Infrared Light From the Sun Boosts ATP Production in Your Mitochondria Without Food (Scientists Just Figured Out How It Works)

• Jeffery et al. (2025) – Longer wavelengths in sunlight penetrating human tissue
• Ma et al. (2018) – Infrared perturbation of charge separation and recombination
• Sanderson et al. (2018) – Inhibitory modulation of cytochrome c oxidase with near-infrared wavelengths
• Dai et al. (2026) – Infrared stimulation of mitochondrial metabolism in deep-sea yeast
• Hayashi et al. (2010) – Water-mediated electron transfer in iron-sulfur bridges
• Marcus and Sutin (1985) – Electron transfer reactions in chemistry

• Jeffery et al. (2025) – Longer wavelengths in sunlight penetrating human tissue
• Ma et al. (2018) – Infrared perturbation of charge separation and recombination
• Sanderson et al. (2018) – Inhibitory modulation of cytochrome c oxidase with near-infrared wavelengths
• Dai et al. (2026) – Infrared stimulation of mitochondrial metabolism in deep-sea yeast
• Hayashi et al. (2010) – Water-mediated electron transfer in iron-sulfur bridges
• Marcus and Sutin (1985) – Electron transfer reactions in chemistry

Sources

• Jeffery et al. (2025) – Longer wavelengths in sunlight penetrating human tissue
• Ma et al. (2018) – Infrared perturbation of charge separation and recombination
• Sanderson et al. (2018) – Inhibitory modulation of cytochrome c oxidase with near-infrared wavelengths
• Dai et al. (2026) – Infrared stimulation of mitochondrial metabolism in deep-sea yeast
• Hayashi et al. (2010) – Water-mediated electron transfer in iron-sulfur bridges
• Marcus and Sutin (1985) – Electron transfer reactions in chemistry

Sources

• Jeffery et al. (2025) – Longer wavelengths in sunlight penetrating human tissue
• Ma et al. (2018) – Infrared perturbation of charge separation and recombination
• Sanderson et al. (2018) – Inhibitory modulation of cytochrome c oxidase with near-infrared wavelengths
• Dai et al. (2026) – Infrared stimulation of mitochondrial metabolism in deep-sea yeast
• Hayashi et al. (2010) – Water-mediated electron transfer in iron-sulfur bridges
• Marcus and Sutin (1985) – Electron transfer reactions in chemistry

I believe that this hypothesis if true has major implications for the built environment and how we live and the type of light that we require to live, and I believe it’s one of the major reasons why we need to be treating our patients outside.

Sources

• Jeffery et al. (2025) – Longer wavelengths in sunlight penetrating human tissue
• Ma et al. (2018) – Infrared perturbation of charge separation and recombination
• Sanderson et al. (2018) – Inhibitory modulation of cytochrome c oxidase with near-infrared wavelengths
• Dai et al. (2026) – Infrared stimulation of mitochondrial metabolism in deep-sea yeast
• Hayashi et al. (2010) – Water-mediated electron transfer in iron-sulfur bridges
• Marcus and Sutin (1985) – Electron transfer reactions in chemistry

I believe that this hypothesis if true has major implications for the built environment and how we live and the type of light that we require to live, and I believe it’s one of the major reasons why we need to be treating our patients outside.

Sources

• Jeffery et al. (2025) – Longer wavelengths in sunlight penetrating human tissue
• Ma et al. (2018) – Infrared perturbation of charge separation and recombination
• Sanderson et al. (2018) – Inhibitory modulation of cytochrome c oxidase with near-infrared wavelengths
• Dai et al. (2026) – Infrared stimulation of mitochondrial metabolism in deep-sea yeast
• Hayashi et al. (2010) – Water-mediated electron transfer in iron-sulfur bridges
• Marcus and Sutin (1985) – Electron transfer reactions in chemistry

It’s a concept that positions sunlight not as a passive environmental factor, but as an active participant in the biochemistry of life itself.

I believe that this hypothesis if true has major implications for the built environment and how we live and the type of light that we require to live, and I believe it’s one of the major reasons why we need to be treating our patients outside.

Sources

• Jeffery et al. (2025) – Longer wavelengths in sunlight penetrating human tissue
• Ma et al. (2018) – Infrared perturbation of charge separation and recombination
• Sanderson et al. (2018) – Inhibitory modulation of cytochrome c oxidase with near-infrared wavelengths
• Dai et al. (2026) – Infrared stimulation of mitochondrial metabolism in deep-sea yeast
• Hayashi et al. (2010) – Water-mediated electron transfer in iron-sulfur bridges
• Marcus and Sutin (1985) – Electron transfer reactions in chemistry

It’s a concept that positions sunlight not as a passive environmental factor, but as an active participant in the biochemistry of life itself.

I believe that this hypothesis if true has major implications for the built environment and how we live and the type of light that we require to live, and I believe it’s one of the major reasons why we need to be treating our patients outside.

Sources

• Jeffery et al. (2025) – Longer wavelengths in sunlight penetrating human tissue
• Ma et al. (2018) – Infrared perturbation of charge separation and recombination
• Sanderson et al. (2018) – Inhibitory modulation of cytochrome c oxidase with near-infrared wavelengths
• Dai et al. (2026) – Infrared stimulation of mitochondrial metabolism in deep-sea yeast
• Hayashi et al. (2010) – Water-mediated electron transfer in iron-sulfur bridges
• Marcus and Sutin (1985) – Electron transfer reactions in chemistry

Seheult introduces a new term: photometabolism—solar-driven, non-photosynthetic modulation of core metabolic processes.

It’s a concept that positions sunlight not as a passive environmental factor, but as an active participant in the biochemistry of life itself.

I believe that this hypothesis if true has major implications for the built environment and how we live and the type of light that we require to live, and I believe it’s one of the major reasons why we need to be treating our patients outside.

Sources

• Jeffery et al. (2025) – Longer wavelengths in sunlight penetrating human tissue
• Ma et al. (2018) – Infrared perturbation of charge separation and recombination
• Sanderson et al. (2018) – Inhibitory modulation of cytochrome c oxidase with near-infrared wavelengths
• Dai et al. (2026) – Infrared stimulation of mitochondrial metabolism in deep-sea yeast
• Hayashi et al. (2010) – Water-mediated electron transfer in iron-sulfur bridges
• Marcus and Sutin (1985) – Electron transfer reactions in chemistry

Seheult introduces a new term: photometabolism—solar-driven, non-photosynthetic modulation of core metabolic processes.

It’s a concept that positions sunlight not as a passive environmental factor, but as an active participant in the biochemistry of life itself.

I believe that this hypothesis if true has major implications for the built environment and how we live and the type of light that we require to live, and I believe it’s one of the major reasons why we need to be treating our patients outside.

Sources

• Jeffery et al. (2025) – Longer wavelengths in sunlight penetrating human tissue
• Ma et al. (2018) – Infrared perturbation of charge separation and recombination
• Sanderson et al. (2018) – Inhibitory modulation of cytochrome c oxidase with near-infrared wavelengths
• Dai et al. (2026) – Infrared stimulation of mitochondrial metabolism in deep-sea yeast
• Hayashi et al. (2010) – Water-mediated electron transfer in iron-sulfur bridges
• Marcus and Sutin (1985) – Electron transfer reactions in chemistry

If validated, the implications extend far beyond biology. Urban planning, architecture, workplace design, and lighting standards may all need reconsideration.

Seheult introduces a new term: photometabolism—solar-driven, non-photosynthetic modulation of core metabolic processes.

It’s a concept that positions sunlight not as a passive environmental factor, but as an active participant in the biochemistry of life itself.

I believe that this hypothesis if true has major implications for the built environment and how we live and the type of light that we require to live, and I believe it’s one of the major reasons why we need to be treating our patients outside.

Sources

• Jeffery et al. (2025) – Longer wavelengths in sunlight penetrating human tissue
• Ma et al. (2018) – Infrared perturbation of charge separation and recombination
• Sanderson et al. (2018) – Inhibitory modulation of cytochrome c oxidase with near-infrared wavelengths
• Dai et al. (2026) – Infrared stimulation of mitochondrial metabolism in deep-sea yeast
• Hayashi et al. (2010) – Water-mediated electron transfer in iron-sulfur bridges
• Marcus and Sutin (1985) – Electron transfer reactions in chemistry

If validated, the implications extend far beyond biology. Urban planning, architecture, workplace design, and lighting standards may all need reconsideration.

Seheult introduces a new term: photometabolism—solar-driven, non-photosynthetic modulation of core metabolic processes.

It’s a concept that positions sunlight not as a passive environmental factor, but as an active participant in the biochemistry of life itself.

I believe that this hypothesis if true has major implications for the built environment and how we live and the type of light that we require to live, and I believe it’s one of the major reasons why we need to be treating our patients outside.

Sources

• Jeffery et al. (2025) – Longer wavelengths in sunlight penetrating human tissue
• Ma et al. (2018) – Infrared perturbation of charge separation and recombination
• Sanderson et al. (2018) – Inhibitory modulation of cytochrome c oxidase with near-infrared wavelengths
• Dai et al. (2026) – Infrared stimulation of mitochondrial metabolism in deep-sea yeast
• Hayashi et al. (2010) – Water-mediated electron transfer in iron-sulfur bridges
• Marcus and Sutin (1985) – Electron transfer reactions in chemistry

The hypothesis is testable. Future experiments could measure how different infrared wavelengths alter specific Marcus crossing configurations in isolated mitochondrial complexes, or track real-time changes in reorganization energy using advanced spectroscopy.

If validated, the implications extend far beyond biology. Urban planning, architecture, workplace design, and lighting standards may all need reconsideration.

Seheult introduces a new term: photometabolism—solar-driven, non-photosynthetic modulation of core metabolic processes.

It’s a concept that positions sunlight not as a passive environmental factor, but as an active participant in the biochemistry of life itself.

I believe that this hypothesis if true has major implications for the built environment and how we live and the type of light that we require to live, and I believe it’s one of the major reasons why we need to be treating our patients outside.

Sources

• Jeffery et al. (2025) – Longer wavelengths in sunlight penetrating human tissue
• Ma et al. (2018) – Infrared perturbation of charge separation and recombination
• Sanderson et al. (2018) – Inhibitory modulation of cytochrome c oxidase with near-infrared wavelengths
• Dai et al. (2026) – Infrared stimulation of mitochondrial metabolism in deep-sea yeast
• Hayashi et al. (2010) – Water-mediated electron transfer in iron-sulfur bridges
• Marcus and Sutin (1985) – Electron transfer reactions in chemistry

The hypothesis is testable. Future experiments could measure how different infrared wavelengths alter specific Marcus crossing configurations in isolated mitochondrial complexes, or track real-time changes in reorganization energy using advanced spectroscopy.

If validated, the implications extend far beyond biology. Urban planning, architecture, workplace design, and lighting standards may all need reconsideration.

Seheult introduces a new term: photometabolism—solar-driven, non-photosynthetic modulation of core metabolic processes.

It’s a concept that positions sunlight not as a passive environmental factor, but as an active participant in the biochemistry of life itself.

I believe that this hypothesis if true has major implications for the built environment and how we live and the type of light that we require to live, and I believe it’s one of the major reasons why we need to be treating our patients outside.

Sources

• Jeffery et al. (2025) – Longer wavelengths in sunlight penetrating human tissue
• Ma et al. (2018) – Infrared perturbation of charge separation and recombination
• Sanderson et al. (2018) – Inhibitory modulation of cytochrome c oxidase with near-infrared wavelengths
• Dai et al. (2026) – Infrared stimulation of mitochondrial metabolism in deep-sea yeast
• Hayashi et al. (2010) – Water-mediated electron transfer in iron-sulfur bridges
• Marcus and Sutin (1985) – Electron transfer reactions in chemistry

What Comes Next

The hypothesis is testable. Future experiments could measure how different infrared wavelengths alter specific Marcus crossing configurations in isolated mitochondrial complexes, or track real-time changes in reorganization energy using advanced spectroscopy.

If validated, the implications extend far beyond biology. Urban planning, architecture, workplace design, and lighting standards may all need reconsideration.

Seheult introduces a new term: photometabolism—solar-driven, non-photosynthetic modulation of core metabolic processes.

It’s a concept that positions sunlight not as a passive environmental factor, but as an active participant in the biochemistry of life itself.

I believe that this hypothesis if true has major implications for the built environment and how we live and the type of light that we require to live, and I believe it’s one of the major reasons why we need to be treating our patients outside.

Sources

• Jeffery et al. (2025) – Longer wavelengths in sunlight penetrating human tissue
• Ma et al. (2018) – Infrared perturbation of charge separation and recombination
• Sanderson et al. (2018) – Inhibitory modulation of cytochrome c oxidase with near-infrared wavelengths
• Dai et al. (2026) – Infrared stimulation of mitochondrial metabolism in deep-sea yeast
• Hayashi et al. (2010) – Water-mediated electron transfer in iron-sulfur bridges
• Marcus and Sutin (1985) – Electron transfer reactions in chemistry

What Comes Next

The hypothesis is testable. Future experiments could measure how different infrared wavelengths alter specific Marcus crossing configurations in isolated mitochondrial complexes, or track real-time changes in reorganization energy using advanced spectroscopy.

If validated, the implications extend far beyond biology. Urban planning, architecture, workplace design, and lighting standards may all need reconsideration.

Seheult introduces a new term: photometabolism—solar-driven, non-photosynthetic modulation of core metabolic processes.

It’s a concept that positions sunlight not as a passive environmental factor, but as an active participant in the biochemistry of life itself.

I believe that this hypothesis if true has major implications for the built environment and how we live and the type of light that we require to live, and I believe it’s one of the major reasons why we need to be treating our patients outside.

Sources

• Jeffery et al. (2025) – Longer wavelengths in sunlight penetrating human tissue
• Ma et al. (2018) – Infrared perturbation of charge separation and recombination
• Sanderson et al. (2018) – Inhibitory modulation of cytochrome c oxidase with near-infrared wavelengths
• Dai et al. (2026) – Infrared stimulation of mitochondrial metabolism in deep-sea yeast
• Hayashi et al. (2010) – Water-mediated electron transfer in iron-sulfur bridges
• Marcus and Sutin (1985) – Electron transfer reactions in chemistry

“The novelty lies in the mechanistic integration,” Seheult emphasizes, “not in any single component.”

What Comes Next

The hypothesis is testable. Future experiments could measure how different infrared wavelengths alter specific Marcus crossing configurations in isolated mitochondrial complexes, or track real-time changes in reorganization energy using advanced spectroscopy.

If validated, the implications extend far beyond biology. Urban planning, architecture, workplace design, and lighting standards may all need reconsideration.

Seheult introduces a new term: photometabolism—solar-driven, non-photosynthetic modulation of core metabolic processes.

It’s a concept that positions sunlight not as a passive environmental factor, but as an active participant in the biochemistry of life itself.

I believe that this hypothesis if true has major implications for the built environment and how we live and the type of light that we require to live, and I believe it’s one of the major reasons why we need to be treating our patients outside.

Sources

• Jeffery et al. (2025) – Longer wavelengths in sunlight penetrating human tissue
• Ma et al. (2018) – Infrared perturbation of charge separation and recombination
• Sanderson et al. (2018) – Inhibitory modulation of cytochrome c oxidase with near-infrared wavelengths
• Dai et al. (2026) – Infrared stimulation of mitochondrial metabolism in deep-sea yeast
• Hayashi et al. (2010) – Water-mediated electron transfer in iron-sulfur bridges
• Marcus and Sutin (1985) – Electron transfer reactions in chemistry

“The novelty lies in the mechanistic integration,” Seheult emphasizes, “not in any single component.”

What Comes Next

The hypothesis is testable. Future experiments could measure how different infrared wavelengths alter specific Marcus crossing configurations in isolated mitochondrial complexes, or track real-time changes in reorganization energy using advanced spectroscopy.

If validated, the implications extend far beyond biology. Urban planning, architecture, workplace design, and lighting standards may all need reconsideration.

Seheult introduces a new term: photometabolism—solar-driven, non-photosynthetic modulation of core metabolic processes.

It’s a concept that positions sunlight not as a passive environmental factor, but as an active participant in the biochemistry of life itself.

I believe that this hypothesis if true has major implications for the built environment and how we live and the type of light that we require to live, and I believe it’s one of the major reasons why we need to be treating our patients outside.

Sources

• Jeffery et al. (2025) – Longer wavelengths in sunlight penetrating human tissue
• Ma et al. (2018) – Infrared perturbation of charge separation and recombination
• Sanderson et al. (2018) – Inhibitory modulation of cytochrome c oxidase with near-infrared wavelengths
• Dai et al. (2026) – Infrared stimulation of mitochondrial metabolism in deep-sea yeast
• Hayashi et al. (2010) – Water-mediated electron transfer in iron-sulfur bridges
• Marcus and Sutin (1985) – Electron transfer reactions in chemistry

• Mitochondrial electron transfer follows Marcus physics
• Red and near-infrared light alter mitochondrial function
• Water and protein structures affect electron transfer kinetics
• Infrared radiation changes molecular electron transfer rates

“The novelty lies in the mechanistic integration,” Seheult emphasizes, “not in any single component.”

What Comes Next

The hypothesis is testable. Future experiments could measure how different infrared wavelengths alter specific Marcus crossing configurations in isolated mitochondrial complexes, or track real-time changes in reorganization energy using advanced spectroscopy.

If validated, the implications extend far beyond biology. Urban planning, architecture, workplace design, and lighting standards may all need reconsideration.

Seheult introduces a new term: photometabolism—solar-driven, non-photosynthetic modulation of core metabolic processes.

It’s a concept that positions sunlight not as a passive environmental factor, but as an active participant in the biochemistry of life itself.

I believe that this hypothesis if true has major implications for the built environment and how we live and the type of light that we require to live, and I believe it’s one of the major reasons why we need to be treating our patients outside.

Sources

• Jeffery et al. (2025) – Longer wavelengths in sunlight penetrating human tissue
• Ma et al. (2018) – Infrared perturbation of charge separation and recombination
• Sanderson et al. (2018) – Inhibitory modulation of cytochrome c oxidase with near-infrared wavelengths
• Dai et al. (2026) – Infrared stimulation of mitochondrial metabolism in deep-sea yeast
• Hayashi et al. (2010) – Water-mediated electron transfer in iron-sulfur bridges
• Marcus and Sutin (1985) – Electron transfer reactions in chemistry

• Mitochondrial electron transfer follows Marcus physics
• Red and near-infrared light alter mitochondrial function
• Water and protein structures affect electron transfer kinetics
• Infrared radiation changes molecular electron transfer rates

“The novelty lies in the mechanistic integration,” Seheult emphasizes, “not in any single component.”

What Comes Next

The hypothesis is testable. Future experiments could measure how different infrared wavelengths alter specific Marcus crossing configurations in isolated mitochondrial complexes, or track real-time changes in reorganization energy using advanced spectroscopy.

If validated, the implications extend far beyond biology. Urban planning, architecture, workplace design, and lighting standards may all need reconsideration.

Seheult introduces a new term: photometabolism—solar-driven, non-photosynthetic modulation of core metabolic processes.

It’s a concept that positions sunlight not as a passive environmental factor, but as an active participant in the biochemistry of life itself.

I believe that this hypothesis if true has major implications for the built environment and how we live and the type of light that we require to live, and I believe it’s one of the major reasons why we need to be treating our patients outside.

Sources

• Jeffery et al. (2025) – Longer wavelengths in sunlight penetrating human tissue
• Ma et al. (2018) – Infrared perturbation of charge separation and recombination
• Sanderson et al. (2018) – Inhibitory modulation of cytochrome c oxidase with near-infrared wavelengths
• Dai et al. (2026) – Infrared stimulation of mitochondrial metabolism in deep-sea yeast
• Hayashi et al. (2010) – Water-mediated electron transfer in iron-sulfur bridges
• Marcus and Sutin (1985) – Electron transfer reactions in chemistry

The paper is the first to integrate four separate literature streams:

• Mitochondrial electron transfer follows Marcus physics
• Red and near-infrared light alter mitochondrial function
• Water and protein structures affect electron transfer kinetics
• Infrared radiation changes molecular electron transfer rates

“The novelty lies in the mechanistic integration,” Seheult emphasizes, “not in any single component.”

What Comes Next

The hypothesis is testable. Future experiments could measure how different infrared wavelengths alter specific Marcus crossing configurations in isolated mitochondrial complexes, or track real-time changes in reorganization energy using advanced spectroscopy.

If validated, the implications extend far beyond biology. Urban planning, architecture, workplace design, and lighting standards may all need reconsideration.

Seheult introduces a new term: photometabolism—solar-driven, non-photosynthetic modulation of core metabolic processes.

It’s a concept that positions sunlight not as a passive environmental factor, but as an active participant in the biochemistry of life itself.

I believe that this hypothesis if true has major implications for the built environment and how we live and the type of light that we require to live, and I believe it’s one of the major reasons why we need to be treating our patients outside.

Sources

• Jeffery et al. (2025) – Longer wavelengths in sunlight penetrating human tissue
• Ma et al. (2018) – Infrared perturbation of charge separation and recombination
• Sanderson et al. (2018) – Inhibitory modulation of cytochrome c oxidase with near-infrared wavelengths
• Dai et al. (2026) – Infrared stimulation of mitochondrial metabolism in deep-sea yeast
• Hayashi et al. (2010) – Water-mediated electron transfer in iron-sulfur bridges
• Marcus and Sutin (1985) – Electron transfer reactions in chemistry

The paper is the first to integrate four separate literature streams:

• Mitochondrial electron transfer follows Marcus physics
• Red and near-infrared light alter mitochondrial function
• Water and protein structures affect electron transfer kinetics
• Infrared radiation changes molecular electron transfer rates

“The novelty lies in the mechanistic integration,” Seheult emphasizes, “not in any single component.”

What Comes Next

The hypothesis is testable. Future experiments could measure how different infrared wavelengths alter specific Marcus crossing configurations in isolated mitochondrial complexes, or track real-time changes in reorganization energy using advanced spectroscopy.

If validated, the implications extend far beyond biology. Urban planning, architecture, workplace design, and lighting standards may all need reconsideration.

Seheult introduces a new term: photometabolism—solar-driven, non-photosynthetic modulation of core metabolic processes.

It’s a concept that positions sunlight not as a passive environmental factor, but as an active participant in the biochemistry of life itself.

I believe that this hypothesis if true has major implications for the built environment and how we live and the type of light that we require to live, and I believe it’s one of the major reasons why we need to be treating our patients outside.

Sources

• Jeffery et al. (2025) – Longer wavelengths in sunlight penetrating human tissue
• Ma et al. (2018) – Infrared perturbation of charge separation and recombination
• Sanderson et al. (2018) – Inhibitory modulation of cytochrome c oxidase with near-infrared wavelengths
• Dai et al. (2026) – Infrared stimulation of mitochondrial metabolism in deep-sea yeast
• Hayashi et al. (2010) – Water-mediated electron transfer in iron-sulfur bridges
• Marcus and Sutin (1985) – Electron transfer reactions in chemistry

The Marcus framework explains phenomena earlier models couldn’t: why some infrared wavelengths inhibit rather than enhance mitochondrial activity, why broadband light outperforms monochromatic sources, and why effects persist across vastly different organisms.

The paper is the first to integrate four separate literature streams:

• Mitochondrial electron transfer follows Marcus physics
• Red and near-infrared light alter mitochondrial function
• Water and protein structures affect electron transfer kinetics
• Infrared radiation changes molecular electron transfer rates

“The novelty lies in the mechanistic integration,” Seheult emphasizes, “not in any single component.”

What Comes Next

The hypothesis is testable. Future experiments could measure how different infrared wavelengths alter specific Marcus crossing configurations in isolated mitochondrial complexes, or track real-time changes in reorganization energy using advanced spectroscopy.

If validated, the implications extend far beyond biology. Urban planning, architecture, workplace design, and lighting standards may all need reconsideration.

Seheult introduces a new term: photometabolism—solar-driven, non-photosynthetic modulation of core metabolic processes.

It’s a concept that positions sunlight not as a passive environmental factor, but as an active participant in the biochemistry of life itself.

I believe that this hypothesis if true has major implications for the built environment and how we live and the type of light that we require to live, and I believe it’s one of the major reasons why we need to be treating our patients outside.

Sources

• Jeffery et al. (2025) – Longer wavelengths in sunlight penetrating human tissue
• Ma et al. (2018) – Infrared perturbation of charge separation and recombination
• Sanderson et al. (2018) – Inhibitory modulation of cytochrome c oxidase with near-infrared wavelengths
• Dai et al. (2026) – Infrared stimulation of mitochondrial metabolism in deep-sea yeast
• Hayashi et al. (2010) – Water-mediated electron transfer in iron-sulfur bridges
• Marcus and Sutin (1985) – Electron transfer reactions in chemistry

The Marcus framework explains phenomena earlier models couldn’t: why some infrared wavelengths inhibit rather than enhance mitochondrial activity, why broadband light outperforms monochromatic sources, and why effects persist across vastly different organisms.

The paper is the first to integrate four separate literature streams:

• Mitochondrial electron transfer follows Marcus physics
• Red and near-infrared light alter mitochondrial function
• Water and protein structures affect electron transfer kinetics
• Infrared radiation changes molecular electron transfer rates

“The novelty lies in the mechanistic integration,” Seheult emphasizes, “not in any single component.”

What Comes Next

The hypothesis is testable. Future experiments could measure how different infrared wavelengths alter specific Marcus crossing configurations in isolated mitochondrial complexes, or track real-time changes in reorganization energy using advanced spectroscopy.

If validated, the implications extend far beyond biology. Urban planning, architecture, workplace design, and lighting standards may all need reconsideration.

Seheult introduces a new term: photometabolism—solar-driven, non-photosynthetic modulation of core metabolic processes.

It’s a concept that positions sunlight not as a passive environmental factor, but as an active participant in the biochemistry of life itself.

I believe that this hypothesis if true has major implications for the built environment and how we live and the type of light that we require to live, and I believe it’s one of the major reasons why we need to be treating our patients outside.

Sources

• Jeffery et al. (2025) – Longer wavelengths in sunlight penetrating human tissue
• Ma et al. (2018) – Infrared perturbation of charge separation and recombination
• Sanderson et al. (2018) – Inhibitory modulation of cytochrome c oxidase with near-infrared wavelengths
• Dai et al. (2026) – Infrared stimulation of mitochondrial metabolism in deep-sea yeast
• Hayashi et al. (2010) – Water-mediated electron transfer in iron-sulfur bridges
• Marcus and Sutin (1985) – Electron transfer reactions in chemistry

Seheult’s team doesn’t reject these mechanisms—but argues they’re incomplete.

The Marcus framework explains phenomena earlier models couldn’t: why some infrared wavelengths inhibit rather than enhance mitochondrial activity, why broadband light outperforms monochromatic sources, and why effects persist across vastly different organisms.

The paper is the first to integrate four separate literature streams:

• Mitochondrial electron transfer follows Marcus physics
• Red and near-infrared light alter mitochondrial function
• Water and protein structures affect electron transfer kinetics
• Infrared radiation changes molecular electron transfer rates

“The novelty lies in the mechanistic integration,” Seheult emphasizes, “not in any single component.”

What Comes Next

The hypothesis is testable. Future experiments could measure how different infrared wavelengths alter specific Marcus crossing configurations in isolated mitochondrial complexes, or track real-time changes in reorganization energy using advanced spectroscopy.

If validated, the implications extend far beyond biology. Urban planning, architecture, workplace design, and lighting standards may all need reconsideration.

Seheult introduces a new term: photometabolism—solar-driven, non-photosynthetic modulation of core metabolic processes.

It’s a concept that positions sunlight not as a passive environmental factor, but as an active participant in the biochemistry of life itself.

I believe that this hypothesis if true has major implications for the built environment and how we live and the type of light that we require to live, and I believe it’s one of the major reasons why we need to be treating our patients outside.

Sources

• Jeffery et al. (2025) – Longer wavelengths in sunlight penetrating human tissue
• Ma et al. (2018) – Infrared perturbation of charge separation and recombination
• Sanderson et al. (2018) – Inhibitory modulation of cytochrome c oxidase with near-infrared wavelengths
• Dai et al. (2026) – Infrared stimulation of mitochondrial metabolism in deep-sea yeast
• Hayashi et al. (2010) – Water-mediated electron transfer in iron-sulfur bridges
• Marcus and Sutin (1985) – Electron transfer reactions in chemistry

Seheult’s team doesn’t reject these mechanisms—but argues they’re incomplete.

The Marcus framework explains phenomena earlier models couldn’t: why some infrared wavelengths inhibit rather than enhance mitochondrial activity, why broadband light outperforms monochromatic sources, and why effects persist across vastly different organisms.

The paper is the first to integrate four separate literature streams:

• Mitochondrial electron transfer follows Marcus physics
• Red and near-infrared light alter mitochondrial function
• Water and protein structures affect electron transfer kinetics
• Infrared radiation changes molecular electron transfer rates

“The novelty lies in the mechanistic integration,” Seheult emphasizes, “not in any single component.”

What Comes Next

The hypothesis is testable. Future experiments could measure how different infrared wavelengths alter specific Marcus crossing configurations in isolated mitochondrial complexes, or track real-time changes in reorganization energy using advanced spectroscopy.

If validated, the implications extend far beyond biology. Urban planning, architecture, workplace design, and lighting standards may all need reconsideration.

Seheult introduces a new term: photometabolism—solar-driven, non-photosynthetic modulation of core metabolic processes.

It’s a concept that positions sunlight not as a passive environmental factor, but as an active participant in the biochemistry of life itself.

I believe that this hypothesis if true has major implications for the built environment and how we live and the type of light that we require to live, and I believe it’s one of the major reasons why we need to be treating our patients outside.

Sources

• Jeffery et al. (2025) – Longer wavelengths in sunlight penetrating human tissue
• Ma et al. (2018) – Infrared perturbation of charge separation and recombination
• Sanderson et al. (2018) – Inhibitory modulation of cytochrome c oxidase with near-infrared wavelengths
• Dai et al. (2026) – Infrared stimulation of mitochondrial metabolism in deep-sea yeast
• Hayashi et al. (2010) – Water-mediated electron transfer in iron-sulfur bridges
• Marcus and Sutin (1985) – Electron transfer reactions in chemistry

Earlier theories proposed infrared light works by activating a photoreceptor in cytochrome c oxidase (complex IV) or by reducing water viscosity around ATP synthase motors.

Seheult’s team doesn’t reject these mechanisms—but argues they’re incomplete.

The Marcus framework explains phenomena earlier models couldn’t: why some infrared wavelengths inhibit rather than enhance mitochondrial activity, why broadband light outperforms monochromatic sources, and why effects persist across vastly different organisms.

The paper is the first to integrate four separate literature streams:

• Mitochondrial electron transfer follows Marcus physics
• Red and near-infrared light alter mitochondrial function
• Water and protein structures affect electron transfer kinetics
• Infrared radiation changes molecular electron transfer rates

“The novelty lies in the mechanistic integration,” Seheult emphasizes, “not in any single component.”

What Comes Next

The hypothesis is testable. Future experiments could measure how different infrared wavelengths alter specific Marcus crossing configurations in isolated mitochondrial complexes, or track real-time changes in reorganization energy using advanced spectroscopy.

If validated, the implications extend far beyond biology. Urban planning, architecture, workplace design, and lighting standards may all need reconsideration.

Seheult introduces a new term: photometabolism—solar-driven, non-photosynthetic modulation of core metabolic processes.

It’s a concept that positions sunlight not as a passive environmental factor, but as an active participant in the biochemistry of life itself.

I believe that this hypothesis if true has major implications for the built environment and how we live and the type of light that we require to live, and I believe it’s one of the major reasons why we need to be treating our patients outside.

Sources

• Jeffery et al. (2025) – Longer wavelengths in sunlight penetrating human tissue
• Ma et al. (2018) – Infrared perturbation of charge separation and recombination
• Sanderson et al. (2018) – Inhibitory modulation of cytochrome c oxidase with near-infrared wavelengths
• Dai et al. (2026) – Infrared stimulation of mitochondrial metabolism in deep-sea yeast
• Hayashi et al. (2010) – Water-mediated electron transfer in iron-sulfur bridges
• Marcus and Sutin (1985) – Electron transfer reactions in chemistry

Earlier theories proposed infrared light works by activating a photoreceptor in cytochrome c oxidase (complex IV) or by reducing water viscosity around ATP synthase motors.

Seheult’s team doesn’t reject these mechanisms—but argues they’re incomplete.

The Marcus framework explains phenomena earlier models couldn’t: why some infrared wavelengths inhibit rather than enhance mitochondrial activity, why broadband light outperforms monochromatic sources, and why effects persist across vastly different organisms.

The paper is the first to integrate four separate literature streams:

• Mitochondrial electron transfer follows Marcus physics
• Red and near-infrared light alter mitochondrial function
• Water and protein structures affect electron transfer kinetics
• Infrared radiation changes molecular electron transfer rates

“The novelty lies in the mechanistic integration,” Seheult emphasizes, “not in any single component.”

What Comes Next

The hypothesis is testable. Future experiments could measure how different infrared wavelengths alter specific Marcus crossing configurations in isolated mitochondrial complexes, or track real-time changes in reorganization energy using advanced spectroscopy.

If validated, the implications extend far beyond biology. Urban planning, architecture, workplace design, and lighting standards may all need reconsideration.

Seheult introduces a new term: photometabolism—solar-driven, non-photosynthetic modulation of core metabolic processes.

It’s a concept that positions sunlight not as a passive environmental factor, but as an active participant in the biochemistry of life itself.

I believe that this hypothesis if true has major implications for the built environment and how we live and the type of light that we require to live, and I believe it’s one of the major reasons why we need to be treating our patients outside.

Sources

• Jeffery et al. (2025) – Longer wavelengths in sunlight penetrating human tissue
• Ma et al. (2018) – Infrared perturbation of charge separation and recombination
• Sanderson et al. (2018) – Inhibitory modulation of cytochrome c oxidase with near-infrared wavelengths
• Dai et al. (2026) – Infrared stimulation of mitochondrial metabolism in deep-sea yeast
• Hayashi et al. (2010) – Water-mediated electron transfer in iron-sulfur bridges
• Marcus and Sutin (1985) – Electron transfer reactions in chemistry

What Makes This Hypothesis Different

Earlier theories proposed infrared light works by activating a photoreceptor in cytochrome c oxidase (complex IV) or by reducing water viscosity around ATP synthase motors.

Seheult’s team doesn’t reject these mechanisms—but argues they’re incomplete.

The Marcus framework explains phenomena earlier models couldn’t: why some infrared wavelengths inhibit rather than enhance mitochondrial activity, why broadband light outperforms monochromatic sources, and why effects persist across vastly different organisms.

The paper is the first to integrate four separate literature streams:

• Mitochondrial electron transfer follows Marcus physics
• Red and near-infrared light alter mitochondrial function
• Water and protein structures affect electron transfer kinetics
• Infrared radiation changes molecular electron transfer rates

“The novelty lies in the mechanistic integration,” Seheult emphasizes, “not in any single component.”

What Comes Next

The hypothesis is testable. Future experiments could measure how different infrared wavelengths alter specific Marcus crossing configurations in isolated mitochondrial complexes, or track real-time changes in reorganization energy using advanced spectroscopy.

If validated, the implications extend far beyond biology. Urban planning, architecture, workplace design, and lighting standards may all need reconsideration.

Seheult introduces a new term: photometabolism—solar-driven, non-photosynthetic modulation of core metabolic processes.

It’s a concept that positions sunlight not as a passive environmental factor, but as an active participant in the biochemistry of life itself.

I believe that this hypothesis if true has major implications for the built environment and how we live and the type of light that we require to live, and I believe it’s one of the major reasons why we need to be treating our patients outside.

Sources

• Jeffery et al. (2025) – Longer wavelengths in sunlight penetrating human tissue
• Ma et al. (2018) – Infrared perturbation of charge separation and recombination
• Sanderson et al. (2018) – Inhibitory modulation of cytochrome c oxidase with near-infrared wavelengths
• Dai et al. (2026) – Infrared stimulation of mitochondrial metabolism in deep-sea yeast
• Hayashi et al. (2010) – Water-mediated electron transfer in iron-sulfur bridges
• Marcus and Sutin (1985) – Electron transfer reactions in chemistry

What Makes This Hypothesis Different

Earlier theories proposed infrared light works by activating a photoreceptor in cytochrome c oxidase (complex IV) or by reducing water viscosity around ATP synthase motors.

Seheult’s team doesn’t reject these mechanisms—but argues they’re incomplete.

The Marcus framework explains phenomena earlier models couldn’t: why some infrared wavelengths inhibit rather than enhance mitochondrial activity, why broadband light outperforms monochromatic sources, and why effects persist across vastly different organisms.

The paper is the first to integrate four separate literature streams:

• Mitochondrial electron transfer follows Marcus physics
• Red and near-infrared light alter mitochondrial function
• Water and protein structures affect electron transfer kinetics
• Infrared radiation changes molecular electron transfer rates

“The novelty lies in the mechanistic integration,” Seheult emphasizes, “not in any single component.”

What Comes Next

The hypothesis is testable. Future experiments could measure how different infrared wavelengths alter specific Marcus crossing configurations in isolated mitochondrial complexes, or track real-time changes in reorganization energy using advanced spectroscopy.

If validated, the implications extend far beyond biology. Urban planning, architecture, workplace design, and lighting standards may all need reconsideration.

Seheult introduces a new term: photometabolism—solar-driven, non-photosynthetic modulation of core metabolic processes.

It’s a concept that positions sunlight not as a passive environmental factor, but as an active participant in the biochemistry of life itself.

I believe that this hypothesis if true has major implications for the built environment and how we live and the type of light that we require to live, and I believe it’s one of the major reasons why we need to be treating our patients outside.

Sources

• Jeffery et al. (2025) – Longer wavelengths in sunlight penetrating human tissue
• Ma et al. (2018) – Infrared perturbation of charge separation and recombination
• Sanderson et al. (2018) – Inhibitory modulation of cytochrome c oxidase with near-infrared wavelengths
• Dai et al. (2026) – Infrared stimulation of mitochondrial metabolism in deep-sea yeast
• Hayashi et al. (2010) – Water-mediated electron transfer in iron-sulfur bridges
• Marcus and Sutin (1985) – Electron transfer reactions in chemistry

This doesn’t prove causation, but it suggests sunlight could be a universal regulator of metabolic activity across the biosphere, with mitochondria in all organisms tuned to respond to the same infrared wavelengths present in Earth’s solar photon field.

What Makes This Hypothesis Different

Earlier theories proposed infrared light works by activating a photoreceptor in cytochrome c oxidase (complex IV) or by reducing water viscosity around ATP synthase motors.

Seheult’s team doesn’t reject these mechanisms—but argues they’re incomplete.

The Marcus framework explains phenomena earlier models couldn’t: why some infrared wavelengths inhibit rather than enhance mitochondrial activity, why broadband light outperforms monochromatic sources, and why effects persist across vastly different organisms.

The paper is the first to integrate four separate literature streams:

• Mitochondrial electron transfer follows Marcus physics
• Red and near-infrared light alter mitochondrial function
• Water and protein structures affect electron transfer kinetics
• Infrared radiation changes molecular electron transfer rates

“The novelty lies in the mechanistic integration,” Seheult emphasizes, “not in any single component.”

What Comes Next

The hypothesis is testable. Future experiments could measure how different infrared wavelengths alter specific Marcus crossing configurations in isolated mitochondrial complexes, or track real-time changes in reorganization energy using advanced spectroscopy.

If validated, the implications extend far beyond biology. Urban planning, architecture, workplace design, and lighting standards may all need reconsideration.

Seheult introduces a new term: photometabolism—solar-driven, non-photosynthetic modulation of core metabolic processes.

It’s a concept that positions sunlight not as a passive environmental factor, but as an active participant in the biochemistry of life itself.

I believe that this hypothesis if true has major implications for the built environment and how we live and the type of light that we require to live, and I believe it’s one of the major reasons why we need to be treating our patients outside.

Sources

• Jeffery et al. (2025) – Longer wavelengths in sunlight penetrating human tissue
• Ma et al. (2018) – Infrared perturbation of charge separation and recombination
• Sanderson et al. (2018) – Inhibitory modulation of cytochrome c oxidase with near-infrared wavelengths
• Dai et al. (2026) – Infrared stimulation of mitochondrial metabolism in deep-sea yeast
• Hayashi et al. (2010) – Water-mediated electron transfer in iron-sulfur bridges
• Marcus and Sutin (1985) – Electron transfer reactions in chemistry

This doesn’t prove causation, but it suggests sunlight could be a universal regulator of metabolic activity across the biosphere, with mitochondria in all organisms tuned to respond to the same infrared wavelengths present in Earth’s solar photon field.

What Makes This Hypothesis Different

Earlier theories proposed infrared light works by activating a photoreceptor in cytochrome c oxidase (complex IV) or by reducing water viscosity around ATP synthase motors.

Seheult’s team doesn’t reject these mechanisms—but argues they’re incomplete.

The Marcus framework explains phenomena earlier models couldn’t: why some infrared wavelengths inhibit rather than enhance mitochondrial activity, why broadband light outperforms monochromatic sources, and why effects persist across vastly different organisms.

The paper is the first to integrate four separate literature streams:

• Mitochondrial electron transfer follows Marcus physics
• Red and near-infrared light alter mitochondrial function
• Water and protein structures affect electron transfer kinetics
• Infrared radiation changes molecular electron transfer rates

“The novelty lies in the mechanistic integration,” Seheult emphasizes, “not in any single component.”

What Comes Next

The hypothesis is testable. Future experiments could measure how different infrared wavelengths alter specific Marcus crossing configurations in isolated mitochondrial complexes, or track real-time changes in reorganization energy using advanced spectroscopy.

If validated, the implications extend far beyond biology. Urban planning, architecture, workplace design, and lighting standards may all need reconsideration.

Seheult introduces a new term: photometabolism—solar-driven, non-photosynthetic modulation of core metabolic processes.

It’s a concept that positions sunlight not as a passive environmental factor, but as an active participant in the biochemistry of life itself.

I believe that this hypothesis if true has major implications for the built environment and how we live and the type of light that we require to live, and I believe it’s one of the major reasons why we need to be treating our patients outside.

Sources

• Jeffery et al. (2025) – Longer wavelengths in sunlight penetrating human tissue
• Ma et al. (2018) – Infrared perturbation of charge separation and recombination
• Sanderson et al. (2018) – Inhibitory modulation of cytochrome c oxidase with near-infrared wavelengths
• Dai et al. (2026) – Infrared stimulation of mitochondrial metabolism in deep-sea yeast
• Hayashi et al. (2010) – Water-mediated electron transfer in iron-sulfur bridges
• Marcus and Sutin (1985) – Electron transfer reactions in chemistry

Solar power intercepted by an organism also scales to the 3/4 power of mass—nearly identical.

This doesn’t prove causation, but it suggests sunlight could be a universal regulator of metabolic activity across the biosphere, with mitochondria in all organisms tuned to respond to the same infrared wavelengths present in Earth’s solar photon field.

What Makes This Hypothesis Different

Earlier theories proposed infrared light works by activating a photoreceptor in cytochrome c oxidase (complex IV) or by reducing water viscosity around ATP synthase motors.

Seheult’s team doesn’t reject these mechanisms—but argues they’re incomplete.

The Marcus framework explains phenomena earlier models couldn’t: why some infrared wavelengths inhibit rather than enhance mitochondrial activity, why broadband light outperforms monochromatic sources, and why effects persist across vastly different organisms.

The paper is the first to integrate four separate literature streams:

• Mitochondrial electron transfer follows Marcus physics
• Red and near-infrared light alter mitochondrial function
• Water and protein structures affect electron transfer kinetics
• Infrared radiation changes molecular electron transfer rates

“The novelty lies in the mechanistic integration,” Seheult emphasizes, “not in any single component.”

What Comes Next

The hypothesis is testable. Future experiments could measure how different infrared wavelengths alter specific Marcus crossing configurations in isolated mitochondrial complexes, or track real-time changes in reorganization energy using advanced spectroscopy.

If validated, the implications extend far beyond biology. Urban planning, architecture, workplace design, and lighting standards may all need reconsideration.

Seheult introduces a new term: photometabolism—solar-driven, non-photosynthetic modulation of core metabolic processes.

It’s a concept that positions sunlight not as a passive environmental factor, but as an active participant in the biochemistry of life itself.

I believe that this hypothesis if true has major implications for the built environment and how we live and the type of light that we require to live, and I believe it’s one of the major reasons why we need to be treating our patients outside.

Sources

• Jeffery et al. (2025) – Longer wavelengths in sunlight penetrating human tissue
• Ma et al. (2018) – Infrared perturbation of charge separation and recombination
• Sanderson et al. (2018) – Inhibitory modulation of cytochrome c oxidase with near-infrared wavelengths
• Dai et al. (2026) – Infrared stimulation of mitochondrial metabolism in deep-sea yeast
• Hayashi et al. (2010) – Water-mediated electron transfer in iron-sulfur bridges
• Marcus and Sutin (1985) – Electron transfer reactions in chemistry

Solar power intercepted by an organism also scales to the 3/4 power of mass—nearly identical.

This doesn’t prove causation, but it suggests sunlight could be a universal regulator of metabolic activity across the biosphere, with mitochondria in all organisms tuned to respond to the same infrared wavelengths present in Earth’s solar photon field.

What Makes This Hypothesis Different

Earlier theories proposed infrared light works by activating a photoreceptor in cytochrome c oxidase (complex IV) or by reducing water viscosity around ATP synthase motors.

Seheult’s team doesn’t reject these mechanisms—but argues they’re incomplete.

The Marcus framework explains phenomena earlier models couldn’t: why some infrared wavelengths inhibit rather than enhance mitochondrial activity, why broadband light outperforms monochromatic sources, and why effects persist across vastly different organisms.

The paper is the first to integrate four separate literature streams:

• Mitochondrial electron transfer follows Marcus physics
• Red and near-infrared light alter mitochondrial function
• Water and protein structures affect electron transfer kinetics
• Infrared radiation changes molecular electron transfer rates

“The novelty lies in the mechanistic integration,” Seheult emphasizes, “not in any single component.”

What Comes Next

The hypothesis is testable. Future experiments could measure how different infrared wavelengths alter specific Marcus crossing configurations in isolated mitochondrial complexes, or track real-time changes in reorganization energy using advanced spectroscopy.

If validated, the implications extend far beyond biology. Urban planning, architecture, workplace design, and lighting standards may all need reconsideration.

Seheult introduces a new term: photometabolism—solar-driven, non-photosynthetic modulation of core metabolic processes.

It’s a concept that positions sunlight not as a passive environmental factor, but as an active participant in the biochemistry of life itself.

I believe that this hypothesis if true has major implications for the built environment and how we live and the type of light that we require to live, and I believe it’s one of the major reasons why we need to be treating our patients outside.

Sources

• Jeffery et al. (2025) – Longer wavelengths in sunlight penetrating human tissue
• Ma et al. (2018) – Infrared perturbation of charge separation and recombination
• Sanderson et al. (2018) – Inhibitory modulation of cytochrome c oxidase with near-infrared wavelengths
• Dai et al. (2026) – Infrared stimulation of mitochondrial metabolism in deep-sea yeast
• Hayashi et al. (2010) – Water-mediated electron transfer in iron-sulfur bridges
• Marcus and Sutin (1985) – Electron transfer reactions in chemistry

One of the paper’s most intriguing observations: metabolic rate scales with body mass to the 3/4 power across species from flies to elephants.

Solar power intercepted by an organism also scales to the 3/4 power of mass—nearly identical.

This doesn’t prove causation, but it suggests sunlight could be a universal regulator of metabolic activity across the biosphere, with mitochondria in all organisms tuned to respond to the same infrared wavelengths present in Earth’s solar photon field.

What Makes This Hypothesis Different

Earlier theories proposed infrared light works by activating a photoreceptor in cytochrome c oxidase (complex IV) or by reducing water viscosity around ATP synthase motors.

Seheult’s team doesn’t reject these mechanisms—but argues they’re incomplete.

The Marcus framework explains phenomena earlier models couldn’t: why some infrared wavelengths inhibit rather than enhance mitochondrial activity, why broadband light outperforms monochromatic sources, and why effects persist across vastly different organisms.

The paper is the first to integrate four separate literature streams:

• Mitochondrial electron transfer follows Marcus physics
• Red and near-infrared light alter mitochondrial function
• Water and protein structures affect electron transfer kinetics
• Infrared radiation changes molecular electron transfer rates

“The novelty lies in the mechanistic integration,” Seheult emphasizes, “not in any single component.”

What Comes Next

The hypothesis is testable. Future experiments could measure how different infrared wavelengths alter specific Marcus crossing configurations in isolated mitochondrial complexes, or track real-time changes in reorganization energy using advanced spectroscopy.

If validated, the implications extend far beyond biology. Urban planning, architecture, workplace design, and lighting standards may all need reconsideration.

Seheult introduces a new term: photometabolism—solar-driven, non-photosynthetic modulation of core metabolic processes.

It’s a concept that positions sunlight not as a passive environmental factor, but as an active participant in the biochemistry of life itself.

I believe that this hypothesis if true has major implications for the built environment and how we live and the type of light that we require to live, and I believe it’s one of the major reasons why we need to be treating our patients outside.

Sources

• Jeffery et al. (2025) – Longer wavelengths in sunlight penetrating human tissue
• Ma et al. (2018) – Infrared perturbation of charge separation and recombination
• Sanderson et al. (2018) – Inhibitory modulation of cytochrome c oxidase with near-infrared wavelengths
• Dai et al. (2026) – Infrared stimulation of mitochondrial metabolism in deep-sea yeast
• Hayashi et al. (2010) – Water-mediated electron transfer in iron-sulfur bridges
• Marcus and Sutin (1985) – Electron transfer reactions in chemistry

One of the paper’s most intriguing observations: metabolic rate scales with body mass to the 3/4 power across species from flies to elephants.

Solar power intercepted by an organism also scales to the 3/4 power of mass—nearly identical.

This doesn’t prove causation, but it suggests sunlight could be a universal regulator of metabolic activity across the biosphere, with mitochondria in all organisms tuned to respond to the same infrared wavelengths present in Earth’s solar photon field.

What Makes This Hypothesis Different

Earlier theories proposed infrared light works by activating a photoreceptor in cytochrome c oxidase (complex IV) or by reducing water viscosity around ATP synthase motors.

Seheult’s team doesn’t reject these mechanisms—but argues they’re incomplete.

The Marcus framework explains phenomena earlier models couldn’t: why some infrared wavelengths inhibit rather than enhance mitochondrial activity, why broadband light outperforms monochromatic sources, and why effects persist across vastly different organisms.

The paper is the first to integrate four separate literature streams:

• Mitochondrial electron transfer follows Marcus physics
• Red and near-infrared light alter mitochondrial function
• Water and protein structures affect electron transfer kinetics
• Infrared radiation changes molecular electron transfer rates

“The novelty lies in the mechanistic integration,” Seheult emphasizes, “not in any single component.”

What Comes Next

The hypothesis is testable. Future experiments could measure how different infrared wavelengths alter specific Marcus crossing configurations in isolated mitochondrial complexes, or track real-time changes in reorganization energy using advanced spectroscopy.

If validated, the implications extend far beyond biology. Urban planning, architecture, workplace design, and lighting standards may all need reconsideration.

Seheult introduces a new term: photometabolism—solar-driven, non-photosynthetic modulation of core metabolic processes.

It’s a concept that positions sunlight not as a passive environmental factor, but as an active participant in the biochemistry of life itself.

I believe that this hypothesis if true has major implications for the built environment and how we live and the type of light that we require to live, and I believe it’s one of the major reasons why we need to be treating our patients outside.

Sources

• Jeffery et al. (2025) – Longer wavelengths in sunlight penetrating human tissue
• Ma et al. (2018) – Infrared perturbation of charge separation and recombination
• Sanderson et al. (2018) – Inhibitory modulation of cytochrome c oxidase with near-infrared wavelengths
• Dai et al. (2026) – Infrared stimulation of mitochondrial metabolism in deep-sea yeast
• Hayashi et al. (2010) – Water-mediated electron transfer in iron-sulfur bridges
• Marcus and Sutin (1985) – Electron transfer reactions in chemistry

Metabolic Scaling Matches Solar Power Scaling

One of the paper’s most intriguing observations: metabolic rate scales with body mass to the 3/4 power across species from flies to elephants.

Solar power intercepted by an organism also scales to the 3/4 power of mass—nearly identical.

This doesn’t prove causation, but it suggests sunlight could be a universal regulator of metabolic activity across the biosphere, with mitochondria in all organisms tuned to respond to the same infrared wavelengths present in Earth’s solar photon field.

What Makes This Hypothesis Different

Earlier theories proposed infrared light works by activating a photoreceptor in cytochrome c oxidase (complex IV) or by reducing water viscosity around ATP synthase motors.

Seheult’s team doesn’t reject these mechanisms—but argues they’re incomplete.

The Marcus framework explains phenomena earlier models couldn’t: why some infrared wavelengths inhibit rather than enhance mitochondrial activity, why broadband light outperforms monochromatic sources, and why effects persist across vastly different organisms.

The paper is the first to integrate four separate literature streams:

• Mitochondrial electron transfer follows Marcus physics
• Red and near-infrared light alter mitochondrial function
• Water and protein structures affect electron transfer kinetics
• Infrared radiation changes molecular electron transfer rates

“The novelty lies in the mechanistic integration,” Seheult emphasizes, “not in any single component.”

What Comes Next

The hypothesis is testable. Future experiments could measure how different infrared wavelengths alter specific Marcus crossing configurations in isolated mitochondrial complexes, or track real-time changes in reorganization energy using advanced spectroscopy.

If validated, the implications extend far beyond biology. Urban planning, architecture, workplace design, and lighting standards may all need reconsideration.

Seheult introduces a new term: photometabolism—solar-driven, non-photosynthetic modulation of core metabolic processes.

It’s a concept that positions sunlight not as a passive environmental factor, but as an active participant in the biochemistry of life itself.

I believe that this hypothesis if true has major implications for the built environment and how we live and the type of light that we require to live, and I believe it’s one of the major reasons why we need to be treating our patients outside.

Sources

• Jeffery et al. (2025) – Longer wavelengths in sunlight penetrating human tissue
• Ma et al. (2018) – Infrared perturbation of charge separation and recombination
• Sanderson et al. (2018) – Inhibitory modulation of cytochrome c oxidase with near-infrared wavelengths
• Dai et al. (2026) – Infrared stimulation of mitochondrial metabolism in deep-sea yeast
• Hayashi et al. (2010) – Water-mediated electron transfer in iron-sulfur bridges
• Marcus and Sutin (1985) – Electron transfer reactions in chemistry

Metabolic Scaling Matches Solar Power Scaling

One of the paper’s most intriguing observations: metabolic rate scales with body mass to the 3/4 power across species from flies to elephants.

Solar power intercepted by an organism also scales to the 3/4 power of mass—nearly identical.

This doesn’t prove causation, but it suggests sunlight could be a universal regulator of metabolic activity across the biosphere, with mitochondria in all organisms tuned to respond to the same infrared wavelengths present in Earth’s solar photon field.

What Makes This Hypothesis Different

Earlier theories proposed infrared light works by activating a photoreceptor in cytochrome c oxidase (complex IV) or by reducing water viscosity around ATP synthase motors.

Seheult’s team doesn’t reject these mechanisms—but argues they’re incomplete.

The Marcus framework explains phenomena earlier models couldn’t: why some infrared wavelengths inhibit rather than enhance mitochondrial activity, why broadband light outperforms monochromatic sources, and why effects persist across vastly different organisms.

The paper is the first to integrate four separate literature streams:

• Mitochondrial electron transfer follows Marcus physics
• Red and near-infrared light alter mitochondrial function
• Water and protein structures affect electron transfer kinetics
• Infrared radiation changes molecular electron transfer rates

“The novelty lies in the mechanistic integration,” Seheult emphasizes, “not in any single component.”

What Comes Next

The hypothesis is testable. Future experiments could measure how different infrared wavelengths alter specific Marcus crossing configurations in isolated mitochondrial complexes, or track real-time changes in reorganization energy using advanced spectroscopy.

If validated, the implications extend far beyond biology. Urban planning, architecture, workplace design, and lighting standards may all need reconsideration.

Seheult introduces a new term: photometabolism—solar-driven, non-photosynthetic modulation of core metabolic processes.

It’s a concept that positions sunlight not as a passive environmental factor, but as an active participant in the biochemistry of life itself.

I believe that this hypothesis if true has major implications for the built environment and how we live and the type of light that we require to live, and I believe it’s one of the major reasons why we need to be treating our patients outside.

Sources

• Jeffery et al. (2025) – Longer wavelengths in sunlight penetrating human tissue
• Ma et al. (2018) – Infrared perturbation of charge separation and recombination
• Sanderson et al. (2018) – Inhibitory modulation of cytochrome c oxidase with near-infrared wavelengths
• Dai et al. (2026) – Infrared stimulation of mitochondrial metabolism in deep-sea yeast
• Hayashi et al. (2010) – Water-mediated electron transfer in iron-sulfur bridges
• Marcus and Sutin (1985) – Electron transfer reactions in chemistry

Randomized controlled trials using infrared vests delivering roughly 20–30 watts per square meter (comparable to sitting under a tree) showed 30% reductions in ICU length of stay and improved muscle strength in critically ill COVID-19 patients.

Metabolic Scaling Matches Solar Power Scaling

One of the paper’s most intriguing observations: metabolic rate scales with body mass to the 3/4 power across species from flies to elephants.

Solar power intercepted by an organism also scales to the 3/4 power of mass—nearly identical.

This doesn’t prove causation, but it suggests sunlight could be a universal regulator of metabolic activity across the biosphere, with mitochondria in all organisms tuned to respond to the same infrared wavelengths present in Earth’s solar photon field.

What Makes This Hypothesis Different

Earlier theories proposed infrared light works by activating a photoreceptor in cytochrome c oxidase (complex IV) or by reducing water viscosity around ATP synthase motors.

Seheult’s team doesn’t reject these mechanisms—but argues they’re incomplete.

The Marcus framework explains phenomena earlier models couldn’t: why some infrared wavelengths inhibit rather than enhance mitochondrial activity, why broadband light outperforms monochromatic sources, and why effects persist across vastly different organisms.

The paper is the first to integrate four separate literature streams:

• Mitochondrial electron transfer follows Marcus physics
• Red and near-infrared light alter mitochondrial function
• Water and protein structures affect electron transfer kinetics
• Infrared radiation changes molecular electron transfer rates

“The novelty lies in the mechanistic integration,” Seheult emphasizes, “not in any single component.”

What Comes Next

The hypothesis is testable. Future experiments could measure how different infrared wavelengths alter specific Marcus crossing configurations in isolated mitochondrial complexes, or track real-time changes in reorganization energy using advanced spectroscopy.

If validated, the implications extend far beyond biology. Urban planning, architecture, workplace design, and lighting standards may all need reconsideration.

Seheult introduces a new term: photometabolism—solar-driven, non-photosynthetic modulation of core metabolic processes.

It’s a concept that positions sunlight not as a passive environmental factor, but as an active participant in the biochemistry of life itself.

I believe that this hypothesis if true has major implications for the built environment and how we live and the type of light that we require to live, and I believe it’s one of the major reasons why we need to be treating our patients outside.

Sources

• Jeffery et al. (2025) – Longer wavelengths in sunlight penetrating human tissue
• Ma et al. (2018) – Infrared perturbation of charge separation and recombination
• Sanderson et al. (2018) – Inhibitory modulation of cytochrome c oxidase with near-infrared wavelengths
• Dai et al. (2026) – Infrared stimulation of mitochondrial metabolism in deep-sea yeast
• Hayashi et al. (2010) – Water-mediated electron transfer in iron-sulfur bridges
• Marcus and Sutin (1985) – Electron transfer reactions in chemistry

Randomized controlled trials using infrared vests delivering roughly 20–30 watts per square meter (comparable to sitting under a tree) showed 30% reductions in ICU length of stay and improved muscle strength in critically ill COVID-19 patients.

Metabolic Scaling Matches Solar Power Scaling

One of the paper’s most intriguing observations: metabolic rate scales with body mass to the 3/4 power across species from flies to elephants.

Solar power intercepted by an organism also scales to the 3/4 power of mass—nearly identical.

This doesn’t prove causation, but it suggests sunlight could be a universal regulator of metabolic activity across the biosphere, with mitochondria in all organisms tuned to respond to the same infrared wavelengths present in Earth’s solar photon field.

What Makes This Hypothesis Different

Earlier theories proposed infrared light works by activating a photoreceptor in cytochrome c oxidase (complex IV) or by reducing water viscosity around ATP synthase motors.

Seheult’s team doesn’t reject these mechanisms—but argues they’re incomplete.

The Marcus framework explains phenomena earlier models couldn’t: why some infrared wavelengths inhibit rather than enhance mitochondrial activity, why broadband light outperforms monochromatic sources, and why effects persist across vastly different organisms.

The paper is the first to integrate four separate literature streams:

• Mitochondrial electron transfer follows Marcus physics
• Red and near-infrared light alter mitochondrial function
• Water and protein structures affect electron transfer kinetics
• Infrared radiation changes molecular electron transfer rates

“The novelty lies in the mechanistic integration,” Seheult emphasizes, “not in any single component.”

What Comes Next

The hypothesis is testable. Future experiments could measure how different infrared wavelengths alter specific Marcus crossing configurations in isolated mitochondrial complexes, or track real-time changes in reorganization energy using advanced spectroscopy.

If validated, the implications extend far beyond biology. Urban planning, architecture, workplace design, and lighting standards may all need reconsideration.

Seheult introduces a new term: photometabolism—solar-driven, non-photosynthetic modulation of core metabolic processes.

It’s a concept that positions sunlight not as a passive environmental factor, but as an active participant in the biochemistry of life itself.

I believe that this hypothesis if true has major implications for the built environment and how we live and the type of light that we require to live, and I believe it’s one of the major reasons why we need to be treating our patients outside.

Sources

• Jeffery et al. (2025) – Longer wavelengths in sunlight penetrating human tissue
• Ma et al. (2018) – Infrared perturbation of charge separation and recombination
• Sanderson et al. (2018) – Inhibitory modulation of cytochrome c oxidase with near-infrared wavelengths
• Dai et al. (2026) – Infrared stimulation of mitochondrial metabolism in deep-sea yeast
• Hayashi et al. (2010) – Water-mediated electron transfer in iron-sulfur bridges
• Marcus and Sutin (1985) – Electron transfer reactions in chemistry

St. George’s Hospital in London followed suit, creating a neurointensive care rooftop unit. Queen Camilla visited the facility in 2026 to recognize the innovation.

Randomized controlled trials using infrared vests delivering roughly 20–30 watts per square meter (comparable to sitting under a tree) showed 30% reductions in ICU length of stay and improved muscle strength in critically ill COVID-19 patients.

Metabolic Scaling Matches Solar Power Scaling

One of the paper’s most intriguing observations: metabolic rate scales with body mass to the 3/4 power across species from flies to elephants.

Solar power intercepted by an organism also scales to the 3/4 power of mass—nearly identical.

This doesn’t prove causation, but it suggests sunlight could be a universal regulator of metabolic activity across the biosphere, with mitochondria in all organisms tuned to respond to the same infrared wavelengths present in Earth’s solar photon field.

What Makes This Hypothesis Different

Earlier theories proposed infrared light works by activating a photoreceptor in cytochrome c oxidase (complex IV) or by reducing water viscosity around ATP synthase motors.

Seheult’s team doesn’t reject these mechanisms—but argues they’re incomplete.

The Marcus framework explains phenomena earlier models couldn’t: why some infrared wavelengths inhibit rather than enhance mitochondrial activity, why broadband light outperforms monochromatic sources, and why effects persist across vastly different organisms.

The paper is the first to integrate four separate literature streams:

• Mitochondrial electron transfer follows Marcus physics
• Red and near-infrared light alter mitochondrial function
• Water and protein structures affect electron transfer kinetics
• Infrared radiation changes molecular electron transfer rates

“The novelty lies in the mechanistic integration,” Seheult emphasizes, “not in any single component.”

What Comes Next

The hypothesis is testable. Future experiments could measure how different infrared wavelengths alter specific Marcus crossing configurations in isolated mitochondrial complexes, or track real-time changes in reorganization energy using advanced spectroscopy.

If validated, the implications extend far beyond biology. Urban planning, architecture, workplace design, and lighting standards may all need reconsideration.

Seheult introduces a new term: photometabolism—solar-driven, non-photosynthetic modulation of core metabolic processes.

It’s a concept that positions sunlight not as a passive environmental factor, but as an active participant in the biochemistry of life itself.

I believe that this hypothesis if true has major implications for the built environment and how we live and the type of light that we require to live, and I believe it’s one of the major reasons why we need to be treating our patients outside.

Sources

• Jeffery et al. (2025) – Longer wavelengths in sunlight penetrating human tissue
• Ma et al. (2018) – Infrared perturbation of charge separation and recombination
• Sanderson et al. (2018) – Inhibitory modulation of cytochrome c oxidase with near-infrared wavelengths
• Dai et al. (2026) – Infrared stimulation of mitochondrial metabolism in deep-sea yeast
• Hayashi et al. (2010) – Water-mediated electron transfer in iron-sulfur bridges
• Marcus and Sutin (1985) – Electron transfer reactions in chemistry

St. George’s Hospital in London followed suit, creating a neurointensive care rooftop unit. Queen Camilla visited the facility in 2026 to recognize the innovation.

Randomized controlled trials using infrared vests delivering roughly 20–30 watts per square meter (comparable to sitting under a tree) showed 30% reductions in ICU length of stay and improved muscle strength in critically ill COVID-19 patients.

Metabolic Scaling Matches Solar Power Scaling

One of the paper’s most intriguing observations: metabolic rate scales with body mass to the 3/4 power across species from flies to elephants.

Solar power intercepted by an organism also scales to the 3/4 power of mass—nearly identical.

This doesn’t prove causation, but it suggests sunlight could be a universal regulator of metabolic activity across the biosphere, with mitochondria in all organisms tuned to respond to the same infrared wavelengths present in Earth’s solar photon field.

What Makes This Hypothesis Different

Earlier theories proposed infrared light works by activating a photoreceptor in cytochrome c oxidase (complex IV) or by reducing water viscosity around ATP synthase motors.

Seheult’s team doesn’t reject these mechanisms—but argues they’re incomplete.

The Marcus framework explains phenomena earlier models couldn’t: why some infrared wavelengths inhibit rather than enhance mitochondrial activity, why broadband light outperforms monochromatic sources, and why effects persist across vastly different organisms.

The paper is the first to integrate four separate literature streams:

• Mitochondrial electron transfer follows Marcus physics
• Red and near-infrared light alter mitochondrial function
• Water and protein structures affect electron transfer kinetics
• Infrared radiation changes molecular electron transfer rates

“The novelty lies in the mechanistic integration,” Seheult emphasizes, “not in any single component.”

What Comes Next

The hypothesis is testable. Future experiments could measure how different infrared wavelengths alter specific Marcus crossing configurations in isolated mitochondrial complexes, or track real-time changes in reorganization energy using advanced spectroscopy.

If validated, the implications extend far beyond biology. Urban planning, architecture, workplace design, and lighting standards may all need reconsideration.

Seheult introduces a new term: photometabolism—solar-driven, non-photosynthetic modulation of core metabolic processes.

It’s a concept that positions sunlight not as a passive environmental factor, but as an active participant in the biochemistry of life itself.

I believe that this hypothesis if true has major implications for the built environment and how we live and the type of light that we require to live, and I believe it’s one of the major reasons why we need to be treating our patients outside.

Sources

• Jeffery et al. (2025) – Longer wavelengths in sunlight penetrating human tissue
• Ma et al. (2018) – Infrared perturbation of charge separation and recombination
• Sanderson et al. (2018) – Inhibitory modulation of cytochrome c oxidase with near-infrared wavelengths
• Dai et al. (2026) – Infrared stimulation of mitochondrial metabolism in deep-sea yeast
• Hayashi et al. (2010) – Water-mediated electron transfer in iron-sulfur bridges
• Marcus and Sutin (1985) – Electron transfer reactions in chemistry

A $1.5 billion hospital in Footscray, Australia, built ICU beds with direct outdoor access. King’s College Hospital in London invested £2 million to transform its rooftop into a critical care garden where up to six ICU patients can receive treatment surrounded by greenery and natural light.

St. George’s Hospital in London followed suit, creating a neurointensive care rooftop unit. Queen Camilla visited the facility in 2026 to recognize the innovation.

Randomized controlled trials using infrared vests delivering roughly 20–30 watts per square meter (comparable to sitting under a tree) showed 30% reductions in ICU length of stay and improved muscle strength in critically ill COVID-19 patients.

Metabolic Scaling Matches Solar Power Scaling

One of the paper’s most intriguing observations: metabolic rate scales with body mass to the 3/4 power across species from flies to elephants.

Solar power intercepted by an organism also scales to the 3/4 power of mass—nearly identical.

This doesn’t prove causation, but it suggests sunlight could be a universal regulator of metabolic activity across the biosphere, with mitochondria in all organisms tuned to respond to the same infrared wavelengths present in Earth’s solar photon field.

What Makes This Hypothesis Different

Earlier theories proposed infrared light works by activating a photoreceptor in cytochrome c oxidase (complex IV) or by reducing water viscosity around ATP synthase motors.

Seheult’s team doesn’t reject these mechanisms—but argues they’re incomplete.

The Marcus framework explains phenomena earlier models couldn’t: why some infrared wavelengths inhibit rather than enhance mitochondrial activity, why broadband light outperforms monochromatic sources, and why effects persist across vastly different organisms.

The paper is the first to integrate four separate literature streams:

• Mitochondrial electron transfer follows Marcus physics
• Red and near-infrared light alter mitochondrial function
• Water and protein structures affect electron transfer kinetics
• Infrared radiation changes molecular electron transfer rates

“The novelty lies in the mechanistic integration,” Seheult emphasizes, “not in any single component.”

What Comes Next

The hypothesis is testable. Future experiments could measure how different infrared wavelengths alter specific Marcus crossing configurations in isolated mitochondrial complexes, or track real-time changes in reorganization energy using advanced spectroscopy.

If validated, the implications extend far beyond biology. Urban planning, architecture, workplace design, and lighting standards may all need reconsideration.

Seheult introduces a new term: photometabolism—solar-driven, non-photosynthetic modulation of core metabolic processes.

It’s a concept that positions sunlight not as a passive environmental factor, but as an active participant in the biochemistry of life itself.

I believe that this hypothesis if true has major implications for the built environment and how we live and the type of light that we require to live, and I believe it’s one of the major reasons why we need to be treating our patients outside.

Sources

• Jeffery et al. (2025) – Longer wavelengths in sunlight penetrating human tissue
• Ma et al. (2018) – Infrared perturbation of charge separation and recombination
• Sanderson et al. (2018) – Inhibitory modulation of cytochrome c oxidase with near-infrared wavelengths
• Dai et al. (2026) – Infrared stimulation of mitochondrial metabolism in deep-sea yeast
• Hayashi et al. (2010) – Water-mediated electron transfer in iron-sulfur bridges
• Marcus and Sutin (1985) – Electron transfer reactions in chemistry

A $1.5 billion hospital in Footscray, Australia, built ICU beds with direct outdoor access. King’s College Hospital in London invested £2 million to transform its rooftop into a critical care garden where up to six ICU patients can receive treatment surrounded by greenery and natural light.

St. George’s Hospital in London followed suit, creating a neurointensive care rooftop unit. Queen Camilla visited the facility in 2026 to recognize the innovation.

Randomized controlled trials using infrared vests delivering roughly 20–30 watts per square meter (comparable to sitting under a tree) showed 30% reductions in ICU length of stay and improved muscle strength in critically ill COVID-19 patients.

Metabolic Scaling Matches Solar Power Scaling

One of the paper’s most intriguing observations: metabolic rate scales with body mass to the 3/4 power across species from flies to elephants.

Solar power intercepted by an organism also scales to the 3/4 power of mass—nearly identical.

This doesn’t prove causation, but it suggests sunlight could be a universal regulator of metabolic activity across the biosphere, with mitochondria in all organisms tuned to respond to the same infrared wavelengths present in Earth’s solar photon field.

What Makes This Hypothesis Different

Earlier theories proposed infrared light works by activating a photoreceptor in cytochrome c oxidase (complex IV) or by reducing water viscosity around ATP synthase motors.

Seheult’s team doesn’t reject these mechanisms—but argues they’re incomplete.

The Marcus framework explains phenomena earlier models couldn’t: why some infrared wavelengths inhibit rather than enhance mitochondrial activity, why broadband light outperforms monochromatic sources, and why effects persist across vastly different organisms.

The paper is the first to integrate four separate literature streams:

• Mitochondrial electron transfer follows Marcus physics
• Red and near-infrared light alter mitochondrial function
• Water and protein structures affect electron transfer kinetics
• Infrared radiation changes molecular electron transfer rates

“The novelty lies in the mechanistic integration,” Seheult emphasizes, “not in any single component.”

What Comes Next

The hypothesis is testable. Future experiments could measure how different infrared wavelengths alter specific Marcus crossing configurations in isolated mitochondrial complexes, or track real-time changes in reorganization energy using advanced spectroscopy.

If validated, the implications extend far beyond biology. Urban planning, architecture, workplace design, and lighting standards may all need reconsideration.

Seheult introduces a new term: photometabolism—solar-driven, non-photosynthetic modulation of core metabolic processes.

It’s a concept that positions sunlight not as a passive environmental factor, but as an active participant in the biochemistry of life itself.

I believe that this hypothesis if true has major implications for the built environment and how we live and the type of light that we require to live, and I believe it’s one of the major reasons why we need to be treating our patients outside.

Sources

• Jeffery et al. (2025) – Longer wavelengths in sunlight penetrating human tissue
• Ma et al. (2018) – Infrared perturbation of charge separation and recombination
• Sanderson et al. (2018) – Inhibitory modulation of cytochrome c oxidase with near-infrared wavelengths
• Dai et al. (2026) – Infrared stimulation of mitochondrial metabolism in deep-sea yeast
• Hayashi et al. (2010) – Water-mediated electron transfer in iron-sulfur bridges
• Marcus and Sutin (1985) – Electron transfer reactions in chemistry

Armed with mounting evidence, hospitals worldwide are redesigning care spaces to maximize sunlight exposure.

A $1.5 billion hospital in Footscray, Australia, built ICU beds with direct outdoor access. King’s College Hospital in London invested £2 million to transform its rooftop into a critical care garden where up to six ICU patients can receive treatment surrounded by greenery and natural light.

St. George’s Hospital in London followed suit, creating a neurointensive care rooftop unit. Queen Camilla visited the facility in 2026 to recognize the innovation.

Randomized controlled trials using infrared vests delivering roughly 20–30 watts per square meter (comparable to sitting under a tree) showed 30% reductions in ICU length of stay and improved muscle strength in critically ill COVID-19 patients.

Metabolic Scaling Matches Solar Power Scaling

One of the paper’s most intriguing observations: metabolic rate scales with body mass to the 3/4 power across species from flies to elephants.

Solar power intercepted by an organism also scales to the 3/4 power of mass—nearly identical.

This doesn’t prove causation, but it suggests sunlight could be a universal regulator of metabolic activity across the biosphere, with mitochondria in all organisms tuned to respond to the same infrared wavelengths present in Earth’s solar photon field.

What Makes This Hypothesis Different

Earlier theories proposed infrared light works by activating a photoreceptor in cytochrome c oxidase (complex IV) or by reducing water viscosity around ATP synthase motors.

Seheult’s team doesn’t reject these mechanisms—but argues they’re incomplete.

The Marcus framework explains phenomena earlier models couldn’t: why some infrared wavelengths inhibit rather than enhance mitochondrial activity, why broadband light outperforms monochromatic sources, and why effects persist across vastly different organisms.

The paper is the first to integrate four separate literature streams:

• Mitochondrial electron transfer follows Marcus physics
• Red and near-infrared light alter mitochondrial function
• Water and protein structures affect electron transfer kinetics
• Infrared radiation changes molecular electron transfer rates

“The novelty lies in the mechanistic integration,” Seheult emphasizes, “not in any single component.”

What Comes Next

The hypothesis is testable. Future experiments could measure how different infrared wavelengths alter specific Marcus crossing configurations in isolated mitochondrial complexes, or track real-time changes in reorganization energy using advanced spectroscopy.

If validated, the implications extend far beyond biology. Urban planning, architecture, workplace design, and lighting standards may all need reconsideration.

Seheult introduces a new term: photometabolism—solar-driven, non-photosynthetic modulation of core metabolic processes.

It’s a concept that positions sunlight not as a passive environmental factor, but as an active participant in the biochemistry of life itself.

I believe that this hypothesis if true has major implications for the built environment and how we live and the type of light that we require to live, and I believe it’s one of the major reasons why we need to be treating our patients outside.

Sources

• Jeffery et al. (2025) – Longer wavelengths in sunlight penetrating human tissue
• Ma et al. (2018) – Infrared perturbation of charge separation and recombination
• Sanderson et al. (2018) – Inhibitory modulation of cytochrome c oxidase with near-infrared wavelengths
• Dai et al. (2026) – Infrared stimulation of mitochondrial metabolism in deep-sea yeast
• Hayashi et al. (2010) – Water-mediated electron transfer in iron-sulfur bridges
• Marcus and Sutin (1985) – Electron transfer reactions in chemistry

Armed with mounting evidence, hospitals worldwide are redesigning care spaces to maximize sunlight exposure.

A $1.5 billion hospital in Footscray, Australia, built ICU beds with direct outdoor access. King’s College Hospital in London invested £2 million to transform its rooftop into a critical care garden where up to six ICU patients can receive treatment surrounded by greenery and natural light.

St. George’s Hospital in London followed suit, creating a neurointensive care rooftop unit. Queen Camilla visited the facility in 2026 to recognize the innovation.

Randomized controlled trials using infrared vests delivering roughly 20–30 watts per square meter (comparable to sitting under a tree) showed 30% reductions in ICU length of stay and improved muscle strength in critically ill COVID-19 patients.

Metabolic Scaling Matches Solar Power Scaling

One of the paper’s most intriguing observations: metabolic rate scales with body mass to the 3/4 power across species from flies to elephants.

Solar power intercepted by an organism also scales to the 3/4 power of mass—nearly identical.

This doesn’t prove causation, but it suggests sunlight could be a universal regulator of metabolic activity across the biosphere, with mitochondria in all organisms tuned to respond to the same infrared wavelengths present in Earth’s solar photon field.

What Makes This Hypothesis Different

Earlier theories proposed infrared light works by activating a photoreceptor in cytochrome c oxidase (complex IV) or by reducing water viscosity around ATP synthase motors.

Seheult’s team doesn’t reject these mechanisms—but argues they’re incomplete.

The Marcus framework explains phenomena earlier models couldn’t: why some infrared wavelengths inhibit rather than enhance mitochondrial activity, why broadband light outperforms monochromatic sources, and why effects persist across vastly different organisms.

The paper is the first to integrate four separate literature streams:

• Mitochondrial electron transfer follows Marcus physics
• Red and near-infrared light alter mitochondrial function
• Water and protein structures affect electron transfer kinetics
• Infrared radiation changes molecular electron transfer rates

“The novelty lies in the mechanistic integration,” Seheult emphasizes, “not in any single component.”

What Comes Next

The hypothesis is testable. Future experiments could measure how different infrared wavelengths alter specific Marcus crossing configurations in isolated mitochondrial complexes, or track real-time changes in reorganization energy using advanced spectroscopy.

If validated, the implications extend far beyond biology. Urban planning, architecture, workplace design, and lighting standards may all need reconsideration.

Seheult introduces a new term: photometabolism—solar-driven, non-photosynthetic modulation of core metabolic processes.

It’s a concept that positions sunlight not as a passive environmental factor, but as an active participant in the biochemistry of life itself.

I believe that this hypothesis if true has major implications for the built environment and how we live and the type of light that we require to live, and I believe it’s one of the major reasons why we need to be treating our patients outside.

Sources

• Jeffery et al. (2025) – Longer wavelengths in sunlight penetrating human tissue
• Ma et al. (2018) – Infrared perturbation of charge separation and recombination
• Sanderson et al. (2018) – Inhibitory modulation of cytochrome c oxidase with near-infrared wavelengths
• Dai et al. (2026) – Infrared stimulation of mitochondrial metabolism in deep-sea yeast
• Hayashi et al. (2010) – Water-mediated electron transfer in iron-sulfur bridges
• Marcus and Sutin (1985) – Electron transfer reactions in chemistry

Hospitals Are Bringing Patients Outside

Armed with mounting evidence, hospitals worldwide are redesigning care spaces to maximize sunlight exposure.

A $1.5 billion hospital in Footscray, Australia, built ICU beds with direct outdoor access. King’s College Hospital in London invested £2 million to transform its rooftop into a critical care garden where up to six ICU patients can receive treatment surrounded by greenery and natural light.

St. George’s Hospital in London followed suit, creating a neurointensive care rooftop unit. Queen Camilla visited the facility in 2026 to recognize the innovation.

Randomized controlled trials using infrared vests delivering roughly 20–30 watts per square meter (comparable to sitting under a tree) showed 30% reductions in ICU length of stay and improved muscle strength in critically ill COVID-19 patients.

Metabolic Scaling Matches Solar Power Scaling

One of the paper’s most intriguing observations: metabolic rate scales with body mass to the 3/4 power across species from flies to elephants.

Solar power intercepted by an organism also scales to the 3/4 power of mass—nearly identical.

This doesn’t prove causation, but it suggests sunlight could be a universal regulator of metabolic activity across the biosphere, with mitochondria in all organisms tuned to respond to the same infrared wavelengths present in Earth’s solar photon field.

What Makes This Hypothesis Different

Earlier theories proposed infrared light works by activating a photoreceptor in cytochrome c oxidase (complex IV) or by reducing water viscosity around ATP synthase motors.

Seheult’s team doesn’t reject these mechanisms—but argues they’re incomplete.

The Marcus framework explains phenomena earlier models couldn’t: why some infrared wavelengths inhibit rather than enhance mitochondrial activity, why broadband light outperforms monochromatic sources, and why effects persist across vastly different organisms.

The paper is the first to integrate four separate literature streams:

• Mitochondrial electron transfer follows Marcus physics
• Red and near-infrared light alter mitochondrial function
• Water and protein structures affect electron transfer kinetics
• Infrared radiation changes molecular electron transfer rates

“The novelty lies in the mechanistic integration,” Seheult emphasizes, “not in any single component.”

What Comes Next

The hypothesis is testable. Future experiments could measure how different infrared wavelengths alter specific Marcus crossing configurations in isolated mitochondrial complexes, or track real-time changes in reorganization energy using advanced spectroscopy.

If validated, the implications extend far beyond biology. Urban planning, architecture, workplace design, and lighting standards may all need reconsideration.

Seheult introduces a new term: photometabolism—solar-driven, non-photosynthetic modulation of core metabolic processes.

It’s a concept that positions sunlight not as a passive environmental factor, but as an active participant in the biochemistry of life itself.

I believe that this hypothesis if true has major implications for the built environment and how we live and the type of light that we require to live, and I believe it’s one of the major reasons why we need to be treating our patients outside.

Sources

• Jeffery et al. (2025) – Longer wavelengths in sunlight penetrating human tissue
• Ma et al. (2018) – Infrared perturbation of charge separation and recombination
• Sanderson et al. (2018) – Inhibitory modulation of cytochrome c oxidase with near-infrared wavelengths
• Dai et al. (2026) – Infrared stimulation of mitochondrial metabolism in deep-sea yeast
• Hayashi et al. (2010) – Water-mediated electron transfer in iron-sulfur bridges
• Marcus and Sutin (1985) – Electron transfer reactions in chemistry

Hospitals Are Bringing Patients Outside

Armed with mounting evidence, hospitals worldwide are redesigning care spaces to maximize sunlight exposure.

A $1.5 billion hospital in Footscray, Australia, built ICU beds with direct outdoor access. King’s College Hospital in London invested £2 million to transform its rooftop into a critical care garden where up to six ICU patients can receive treatment surrounded by greenery and natural light.

St. George’s Hospital in London followed suit, creating a neurointensive care rooftop unit. Queen Camilla visited the facility in 2026 to recognize the innovation.

Randomized controlled trials using infrared vests delivering roughly 20–30 watts per square meter (comparable to sitting under a tree) showed 30% reductions in ICU length of stay and improved muscle strength in critically ill COVID-19 patients.

Metabolic Scaling Matches Solar Power Scaling

One of the paper’s most intriguing observations: metabolic rate scales with body mass to the 3/4 power across species from flies to elephants.

Solar power intercepted by an organism also scales to the 3/4 power of mass—nearly identical.

This doesn’t prove causation, but it suggests sunlight could be a universal regulator of metabolic activity across the biosphere, with mitochondria in all organisms tuned to respond to the same infrared wavelengths present in Earth’s solar photon field.

What Makes This Hypothesis Different

Earlier theories proposed infrared light works by activating a photoreceptor in cytochrome c oxidase (complex IV) or by reducing water viscosity around ATP synthase motors.

Seheult’s team doesn’t reject these mechanisms—but argues they’re incomplete.

The Marcus framework explains phenomena earlier models couldn’t: why some infrared wavelengths inhibit rather than enhance mitochondrial activity, why broadband light outperforms monochromatic sources, and why effects persist across vastly different organisms.

The paper is the first to integrate four separate literature streams:

• Mitochondrial electron transfer follows Marcus physics
• Red and near-infrared light alter mitochondrial function
• Water and protein structures affect electron transfer kinetics
• Infrared radiation changes molecular electron transfer rates

“The novelty lies in the mechanistic integration,” Seheult emphasizes, “not in any single component.”

What Comes Next

The hypothesis is testable. Future experiments could measure how different infrared wavelengths alter specific Marcus crossing configurations in isolated mitochondrial complexes, or track real-time changes in reorganization energy using advanced spectroscopy.

If validated, the implications extend far beyond biology. Urban planning, architecture, workplace design, and lighting standards may all need reconsideration.

Seheult introduces a new term: photometabolism—solar-driven, non-photosynthetic modulation of core metabolic processes.

It’s a concept that positions sunlight not as a passive environmental factor, but as an active participant in the biochemistry of life itself.

I believe that this hypothesis if true has major implications for the built environment and how we live and the type of light that we require to live, and I believe it’s one of the major reasons why we need to be treating our patients outside.

Sources

• Jeffery et al. (2025) – Longer wavelengths in sunlight penetrating human tissue
• Ma et al. (2018) – Infrared perturbation of charge separation and recombination
• Sanderson et al. (2018) – Inhibitory modulation of cytochrome c oxidase with near-infrared wavelengths
• Dai et al. (2026) – Infrared stimulation of mitochondrial metabolism in deep-sea yeast
• Hayashi et al. (2010) – Water-mediated electron transfer in iron-sulfur bridges
• Marcus and Sutin (1985) – Electron transfer reactions in chemistry

Multiple studies have linked mortality rates to latitude, independent of vitamin D levels, suggesting sunlight itself—particularly its infrared component—plays a direct metabolic role.

Hospitals Are Bringing Patients Outside

Armed with mounting evidence, hospitals worldwide are redesigning care spaces to maximize sunlight exposure.

A $1.5 billion hospital in Footscray, Australia, built ICU beds with direct outdoor access. King’s College Hospital in London invested £2 million to transform its rooftop into a critical care garden where up to six ICU patients can receive treatment surrounded by greenery and natural light.

St. George’s Hospital in London followed suit, creating a neurointensive care rooftop unit. Queen Camilla visited the facility in 2026 to recognize the innovation.

Randomized controlled trials using infrared vests delivering roughly 20–30 watts per square meter (comparable to sitting under a tree) showed 30% reductions in ICU length of stay and improved muscle strength in critically ill COVID-19 patients.

Metabolic Scaling Matches Solar Power Scaling

One of the paper’s most intriguing observations: metabolic rate scales with body mass to the 3/4 power across species from flies to elephants.

Solar power intercepted by an organism also scales to the 3/4 power of mass—nearly identical.

This doesn’t prove causation, but it suggests sunlight could be a universal regulator of metabolic activity across the biosphere, with mitochondria in all organisms tuned to respond to the same infrared wavelengths present in Earth’s solar photon field.

What Makes This Hypothesis Different

Earlier theories proposed infrared light works by activating a photoreceptor in cytochrome c oxidase (complex IV) or by reducing water viscosity around ATP synthase motors.

Seheult’s team doesn’t reject these mechanisms—but argues they’re incomplete.

The Marcus framework explains phenomena earlier models couldn’t: why some infrared wavelengths inhibit rather than enhance mitochondrial activity, why broadband light outperforms monochromatic sources, and why effects persist across vastly different organisms.

The paper is the first to integrate four separate literature streams:

• Mitochondrial electron transfer follows Marcus physics
• Red and near-infrared light alter mitochondrial function
• Water and protein structures affect electron transfer kinetics
• Infrared radiation changes molecular electron transfer rates

“The novelty lies in the mechanistic integration,” Seheult emphasizes, “not in any single component.”

What Comes Next

The hypothesis is testable. Future experiments could measure how different infrared wavelengths alter specific Marcus crossing configurations in isolated mitochondrial complexes, or track real-time changes in reorganization energy using advanced spectroscopy.

If validated, the implications extend far beyond biology. Urban planning, architecture, workplace design, and lighting standards may all need reconsideration.

Seheult introduces a new term: photometabolism—solar-driven, non-photosynthetic modulation of core metabolic processes.

It’s a concept that positions sunlight not as a passive environmental factor, but as an active participant in the biochemistry of life itself.

I believe that this hypothesis if true has major implications for the built environment and how we live and the type of light that we require to live, and I believe it’s one of the major reasons why we need to be treating our patients outside.

Sources

• Jeffery et al. (2025) – Longer wavelengths in sunlight penetrating human tissue
• Ma et al. (2018) – Infrared perturbation of charge separation and recombination
• Sanderson et al. (2018) – Inhibitory modulation of cytochrome c oxidase with near-infrared wavelengths
• Dai et al. (2026) – Infrared stimulation of mitochondrial metabolism in deep-sea yeast
• Hayashi et al. (2010) – Water-mediated electron transfer in iron-sulfur bridges
• Marcus and Sutin (1985) – Electron transfer reactions in chemistry

Multiple studies have linked mortality rates to latitude, independent of vitamin D levels, suggesting sunlight itself—particularly its infrared component—plays a direct metabolic role.

Hospitals Are Bringing Patients Outside

Armed with mounting evidence, hospitals worldwide are redesigning care spaces to maximize sunlight exposure.

A $1.5 billion hospital in Footscray, Australia, built ICU beds with direct outdoor access. King’s College Hospital in London invested £2 million to transform its rooftop into a critical care garden where up to six ICU patients can receive treatment surrounded by greenery and natural light.

St. George’s Hospital in London followed suit, creating a neurointensive care rooftop unit. Queen Camilla visited the facility in 2026 to recognize the innovation.

Randomized controlled trials using infrared vests delivering roughly 20–30 watts per square meter (comparable to sitting under a tree) showed 30% reductions in ICU length of stay and improved muscle strength in critically ill COVID-19 patients.

Metabolic Scaling Matches Solar Power Scaling

One of the paper’s most intriguing observations: metabolic rate scales with body mass to the 3/4 power across species from flies to elephants.

Solar power intercepted by an organism also scales to the 3/4 power of mass—nearly identical.

This doesn’t prove causation, but it suggests sunlight could be a universal regulator of metabolic activity across the biosphere, with mitochondria in all organisms tuned to respond to the same infrared wavelengths present in Earth’s solar photon field.

What Makes This Hypothesis Different

Earlier theories proposed infrared light works by activating a photoreceptor in cytochrome c oxidase (complex IV) or by reducing water viscosity around ATP synthase motors.

Seheult’s team doesn’t reject these mechanisms—but argues they’re incomplete.

The Marcus framework explains phenomena earlier models couldn’t: why some infrared wavelengths inhibit rather than enhance mitochondrial activity, why broadband light outperforms monochromatic sources, and why effects persist across vastly different organisms.

The paper is the first to integrate four separate literature streams:

• Mitochondrial electron transfer follows Marcus physics
• Red and near-infrared light alter mitochondrial function
• Water and protein structures affect electron transfer kinetics
• Infrared radiation changes molecular electron transfer rates

“The novelty lies in the mechanistic integration,” Seheult emphasizes, “not in any single component.”

What Comes Next

The hypothesis is testable. Future experiments could measure how different infrared wavelengths alter specific Marcus crossing configurations in isolated mitochondrial complexes, or track real-time changes in reorganization energy using advanced spectroscopy.

If validated, the implications extend far beyond biology. Urban planning, architecture, workplace design, and lighting standards may all need reconsideration.

Seheult introduces a new term: photometabolism—solar-driven, non-photosynthetic modulation of core metabolic processes.

It’s a concept that positions sunlight not as a passive environmental factor, but as an active participant in the biochemistry of life itself.

I believe that this hypothesis if true has major implications for the built environment and how we live and the type of light that we require to live, and I believe it’s one of the major reasons why we need to be treating our patients outside.

Sources

• Jeffery et al. (2025) – Longer wavelengths in sunlight penetrating human tissue
• Ma et al. (2018) – Infrared perturbation of charge separation and recombination
• Sanderson et al. (2018) – Inhibitory modulation of cytochrome c oxidase with near-infrared wavelengths
• Dai et al. (2026) – Infrared stimulation of mitochondrial metabolism in deep-sea yeast
• Hayashi et al. (2010) – Water-mediated electron transfer in iron-sulfur bridges
• Marcus and Sutin (1985) – Electron transfer reactions in chemistry

Australia shows the same pattern, but shifted six months—deaths peak in July, their winter. Singapore, 80 miles from the equator with year-round sun, shows no seasonal mortality pattern.

Multiple studies have linked mortality rates to latitude, independent of vitamin D levels, suggesting sunlight itself—particularly its infrared component—plays a direct metabolic role.

Hospitals Are Bringing Patients Outside

Armed with mounting evidence, hospitals worldwide are redesigning care spaces to maximize sunlight exposure.

A $1.5 billion hospital in Footscray, Australia, built ICU beds with direct outdoor access. King’s College Hospital in London invested £2 million to transform its rooftop into a critical care garden where up to six ICU patients can receive treatment surrounded by greenery and natural light.

St. George’s Hospital in London followed suit, creating a neurointensive care rooftop unit. Queen Camilla visited the facility in 2026 to recognize the innovation.

Randomized controlled trials using infrared vests delivering roughly 20–30 watts per square meter (comparable to sitting under a tree) showed 30% reductions in ICU length of stay and improved muscle strength in critically ill COVID-19 patients.

Metabolic Scaling Matches Solar Power Scaling

One of the paper’s most intriguing observations: metabolic rate scales with body mass to the 3/4 power across species from flies to elephants.

Solar power intercepted by an organism also scales to the 3/4 power of mass—nearly identical.

This doesn’t prove causation, but it suggests sunlight could be a universal regulator of metabolic activity across the biosphere, with mitochondria in all organisms tuned to respond to the same infrared wavelengths present in Earth’s solar photon field.

What Makes This Hypothesis Different

Earlier theories proposed infrared light works by activating a photoreceptor in cytochrome c oxidase (complex IV) or by reducing water viscosity around ATP synthase motors.

Seheult’s team doesn’t reject these mechanisms—but argues they’re incomplete.

The Marcus framework explains phenomena earlier models couldn’t: why some infrared wavelengths inhibit rather than enhance mitochondrial activity, why broadband light outperforms monochromatic sources, and why effects persist across vastly different organisms.

The paper is the first to integrate four separate literature streams:

• Mitochondrial electron transfer follows Marcus physics
• Red and near-infrared light alter mitochondrial function
• Water and protein structures affect electron transfer kinetics
• Infrared radiation changes molecular electron transfer rates

“The novelty lies in the mechanistic integration,” Seheult emphasizes, “not in any single component.”

What Comes Next

The hypothesis is testable. Future experiments could measure how different infrared wavelengths alter specific Marcus crossing configurations in isolated mitochondrial complexes, or track real-time changes in reorganization energy using advanced spectroscopy.

If validated, the implications extend far beyond biology. Urban planning, architecture, workplace design, and lighting standards may all need reconsideration.

Seheult introduces a new term: photometabolism—solar-driven, non-photosynthetic modulation of core metabolic processes.

It’s a concept that positions sunlight not as a passive environmental factor, but as an active participant in the biochemistry of life itself.

I believe that this hypothesis if true has major implications for the built environment and how we live and the type of light that we require to live, and I believe it’s one of the major reasons why we need to be treating our patients outside.

Sources

• Jeffery et al. (2025) – Longer wavelengths in sunlight penetrating human tissue
• Ma et al. (2018) – Infrared perturbation of charge separation and recombination
• Sanderson et al. (2018) – Inhibitory modulation of cytochrome c oxidase with near-infrared wavelengths
• Dai et al. (2026) – Infrared stimulation of mitochondrial metabolism in deep-sea yeast
• Hayashi et al. (2010) – Water-mediated electron transfer in iron-sulfur bridges
• Marcus and Sutin (1985) – Electron transfer reactions in chemistry

Australia shows the same pattern, but shifted six months—deaths peak in July, their winter. Singapore, 80 miles from the equator with year-round sun, shows no seasonal mortality pattern.

Multiple studies have linked mortality rates to latitude, independent of vitamin D levels, suggesting sunlight itself—particularly its infrared component—plays a direct metabolic role.

Hospitals Are Bringing Patients Outside

Armed with mounting evidence, hospitals worldwide are redesigning care spaces to maximize sunlight exposure.

A $1.5 billion hospital in Footscray, Australia, built ICU beds with direct outdoor access. King’s College Hospital in London invested £2 million to transform its rooftop into a critical care garden where up to six ICU patients can receive treatment surrounded by greenery and natural light.

St. George’s Hospital in London followed suit, creating a neurointensive care rooftop unit. Queen Camilla visited the facility in 2026 to recognize the innovation.

Randomized controlled trials using infrared vests delivering roughly 20–30 watts per square meter (comparable to sitting under a tree) showed 30% reductions in ICU length of stay and improved muscle strength in critically ill COVID-19 patients.

Metabolic Scaling Matches Solar Power Scaling

One of the paper’s most intriguing observations: metabolic rate scales with body mass to the 3/4 power across species from flies to elephants.

Solar power intercepted by an organism also scales to the 3/4 power of mass—nearly identical.

This doesn’t prove causation, but it suggests sunlight could be a universal regulator of metabolic activity across the biosphere, with mitochondria in all organisms tuned to respond to the same infrared wavelengths present in Earth’s solar photon field.

What Makes This Hypothesis Different

Earlier theories proposed infrared light works by activating a photoreceptor in cytochrome c oxidase (complex IV) or by reducing water viscosity around ATP synthase motors.

Seheult’s team doesn’t reject these mechanisms—but argues they’re incomplete.

The Marcus framework explains phenomena earlier models couldn’t: why some infrared wavelengths inhibit rather than enhance mitochondrial activity, why broadband light outperforms monochromatic sources, and why effects persist across vastly different organisms.

The paper is the first to integrate four separate literature streams:

• Mitochondrial electron transfer follows Marcus physics
• Red and near-infrared light alter mitochondrial function
• Water and protein structures affect electron transfer kinetics
• Infrared radiation changes molecular electron transfer rates

“The novelty lies in the mechanistic integration,” Seheult emphasizes, “not in any single component.”

What Comes Next

The hypothesis is testable. Future experiments could measure how different infrared wavelengths alter specific Marcus crossing configurations in isolated mitochondrial complexes, or track real-time changes in reorganization energy using advanced spectroscopy.

If validated, the implications extend far beyond biology. Urban planning, architecture, workplace design, and lighting standards may all need reconsideration.

Seheult introduces a new term: photometabolism—solar-driven, non-photosynthetic modulation of core metabolic processes.

It’s a concept that positions sunlight not as a passive environmental factor, but as an active participant in the biochemistry of life itself.

I believe that this hypothesis if true has major implications for the built environment and how we live and the type of light that we require to live, and I believe it’s one of the major reasons why we need to be treating our patients outside.

Sources

• Jeffery et al. (2025) – Longer wavelengths in sunlight penetrating human tissue
• Ma et al. (2018) – Infrared perturbation of charge separation and recombination
• Sanderson et al. (2018) – Inhibitory modulation of cytochrome c oxidase with near-infrared wavelengths
• Dai et al. (2026) – Infrared stimulation of mitochondrial metabolism in deep-sea yeast
• Hayashi et al. (2010) – Water-mediated electron transfer in iron-sulfur bridges
• Marcus and Sutin (1985) – Electron transfer reactions in chemistry

This pattern holds across both infectious and non-infectious causes. The seasonal variation in heart disease deaths alone exceeds total influenza deaths during flu season.

Australia shows the same pattern, but shifted six months—deaths peak in July, their winter. Singapore, 80 miles from the equator with year-round sun, shows no seasonal mortality pattern.

Multiple studies have linked mortality rates to latitude, independent of vitamin D levels, suggesting sunlight itself—particularly its infrared component—plays a direct metabolic role.

Hospitals Are Bringing Patients Outside

Armed with mounting evidence, hospitals worldwide are redesigning care spaces to maximize sunlight exposure.

A $1.5 billion hospital in Footscray, Australia, built ICU beds with direct outdoor access. King’s College Hospital in London invested £2 million to transform its rooftop into a critical care garden where up to six ICU patients can receive treatment surrounded by greenery and natural light.

St. George’s Hospital in London followed suit, creating a neurointensive care rooftop unit. Queen Camilla visited the facility in 2026 to recognize the innovation.

Randomized controlled trials using infrared vests delivering roughly 20–30 watts per square meter (comparable to sitting under a tree) showed 30% reductions in ICU length of stay and improved muscle strength in critically ill COVID-19 patients.

Metabolic Scaling Matches Solar Power Scaling

One of the paper’s most intriguing observations: metabolic rate scales with body mass to the 3/4 power across species from flies to elephants.

Solar power intercepted by an organism also scales to the 3/4 power of mass—nearly identical.

This doesn’t prove causation, but it suggests sunlight could be a universal regulator of metabolic activity across the biosphere, with mitochondria in all organisms tuned to respond to the same infrared wavelengths present in Earth’s solar photon field.

What Makes This Hypothesis Different

Earlier theories proposed infrared light works by activating a photoreceptor in cytochrome c oxidase (complex IV) or by reducing water viscosity around ATP synthase motors.

Seheult’s team doesn’t reject these mechanisms—but argues they’re incomplete.

The Marcus framework explains phenomena earlier models couldn’t: why some infrared wavelengths inhibit rather than enhance mitochondrial activity, why broadband light outperforms monochromatic sources, and why effects persist across vastly different organisms.

The paper is the first to integrate four separate literature streams:

• Mitochondrial electron transfer follows Marcus physics
• Red and near-infrared light alter mitochondrial function
• Water and protein structures affect electron transfer kinetics
• Infrared radiation changes molecular electron transfer rates

“The novelty lies in the mechanistic integration,” Seheult emphasizes, “not in any single component.”

What Comes Next

The hypothesis is testable. Future experiments could measure how different infrared wavelengths alter specific Marcus crossing configurations in isolated mitochondrial complexes, or track real-time changes in reorganization energy using advanced spectroscopy.

If validated, the implications extend far beyond biology. Urban planning, architecture, workplace design, and lighting standards may all need reconsideration.

Seheult introduces a new term: photometabolism—solar-driven, non-photosynthetic modulation of core metabolic processes.

It’s a concept that positions sunlight not as a passive environmental factor, but as an active participant in the biochemistry of life itself.

I believe that this hypothesis if true has major implications for the built environment and how we live and the type of light that we require to live, and I believe it’s one of the major reasons why we need to be treating our patients outside.

Sources

• Jeffery et al. (2025) – Longer wavelengths in sunlight penetrating human tissue
• Ma et al. (2018) – Infrared perturbation of charge separation and recombination
• Sanderson et al. (2018) – Inhibitory modulation of cytochrome c oxidase with near-infrared wavelengths
• Dai et al. (2026) – Infrared stimulation of mitochondrial metabolism in deep-sea yeast
• Hayashi et al. (2010) – Water-mediated electron transfer in iron-sulfur bridges
• Marcus and Sutin (1985) – Electron transfer reactions in chemistry

This pattern holds across both infectious and non-infectious causes. The seasonal variation in heart disease deaths alone exceeds total influenza deaths during flu season.

Australia shows the same pattern, but shifted six months—deaths peak in July, their winter. Singapore, 80 miles from the equator with year-round sun, shows no seasonal mortality pattern.

Multiple studies have linked mortality rates to latitude, independent of vitamin D levels, suggesting sunlight itself—particularly its infrared component—plays a direct metabolic role.

Hospitals Are Bringing Patients Outside

Armed with mounting evidence, hospitals worldwide are redesigning care spaces to maximize sunlight exposure.

A $1.5 billion hospital in Footscray, Australia, built ICU beds with direct outdoor access. King’s College Hospital in London invested £2 million to transform its rooftop into a critical care garden where up to six ICU patients can receive treatment surrounded by greenery and natural light.

St. George’s Hospital in London followed suit, creating a neurointensive care rooftop unit. Queen Camilla visited the facility in 2026 to recognize the innovation.

Randomized controlled trials using infrared vests delivering roughly 20–30 watts per square meter (comparable to sitting under a tree) showed 30% reductions in ICU length of stay and improved muscle strength in critically ill COVID-19 patients.

Metabolic Scaling Matches Solar Power Scaling

One of the paper’s most intriguing observations: metabolic rate scales with body mass to the 3/4 power across species from flies to elephants.

Solar power intercepted by an organism also scales to the 3/4 power of mass—nearly identical.

This doesn’t prove causation, but it suggests sunlight could be a universal regulator of metabolic activity across the biosphere, with mitochondria in all organisms tuned to respond to the same infrared wavelengths present in Earth’s solar photon field.

What Makes This Hypothesis Different

Earlier theories proposed infrared light works by activating a photoreceptor in cytochrome c oxidase (complex IV) or by reducing water viscosity around ATP synthase motors.

Seheult’s team doesn’t reject these mechanisms—but argues they’re incomplete.

The Marcus framework explains phenomena earlier models couldn’t: why some infrared wavelengths inhibit rather than enhance mitochondrial activity, why broadband light outperforms monochromatic sources, and why effects persist across vastly different organisms.

The paper is the first to integrate four separate literature streams:

• Mitochondrial electron transfer follows Marcus physics
• Red and near-infrared light alter mitochondrial function
• Water and protein structures affect electron transfer kinetics
• Infrared radiation changes molecular electron transfer rates

“The novelty lies in the mechanistic integration,” Seheult emphasizes, “not in any single component.”

What Comes Next

The hypothesis is testable. Future experiments could measure how different infrared wavelengths alter specific Marcus crossing configurations in isolated mitochondrial complexes, or track real-time changes in reorganization energy using advanced spectroscopy.

If validated, the implications extend far beyond biology. Urban planning, architecture, workplace design, and lighting standards may all need reconsideration.

Seheult introduces a new term: photometabolism—solar-driven, non-photosynthetic modulation of core metabolic processes.

It’s a concept that positions sunlight not as a passive environmental factor, but as an active participant in the biochemistry of life itself.

I believe that this hypothesis if true has major implications for the built environment and how we live and the type of light that we require to live, and I believe it’s one of the major reasons why we need to be treating our patients outside.

Sources

• Jeffery et al. (2025) – Longer wavelengths in sunlight penetrating human tissue
• Ma et al. (2018) – Infrared perturbation of charge separation and recombination
• Sanderson et al. (2018) – Inhibitory modulation of cytochrome c oxidase with near-infrared wavelengths
• Dai et al. (2026) – Infrared stimulation of mitochondrial metabolism in deep-sea yeast
• Hayashi et al. (2010) – Water-mediated electron transfer in iron-sulfur bridges
• Marcus and Sutin (1985) – Electron transfer reactions in chemistry

Death rates from heart disease, cancer, stroke, Alzheimer’s, diabetes, and respiratory illness all peak one to three weeks after the shortest day of the year and bottom out after the longest day.

This pattern holds across both infectious and non-infectious causes. The seasonal variation in heart disease deaths alone exceeds total influenza deaths during flu season.

Australia shows the same pattern, but shifted six months—deaths peak in July, their winter. Singapore, 80 miles from the equator with year-round sun, shows no seasonal mortality pattern.

Multiple studies have linked mortality rates to latitude, independent of vitamin D levels, suggesting sunlight itself—particularly its infrared component—plays a direct metabolic role.

Hospitals Are Bringing Patients Outside

Armed with mounting evidence, hospitals worldwide are redesigning care spaces to maximize sunlight exposure.

A $1.5 billion hospital in Footscray, Australia, built ICU beds with direct outdoor access. King’s College Hospital in London invested £2 million to transform its rooftop into a critical care garden where up to six ICU patients can receive treatment surrounded by greenery and natural light.

St. George’s Hospital in London followed suit, creating a neurointensive care rooftop unit. Queen Camilla visited the facility in 2026 to recognize the innovation.

Randomized controlled trials using infrared vests delivering roughly 20–30 watts per square meter (comparable to sitting under a tree) showed 30% reductions in ICU length of stay and improved muscle strength in critically ill COVID-19 patients.

Metabolic Scaling Matches Solar Power Scaling

One of the paper’s most intriguing observations: metabolic rate scales with body mass to the 3/4 power across species from flies to elephants.

Solar power intercepted by an organism also scales to the 3/4 power of mass—nearly identical.

This doesn’t prove causation, but it suggests sunlight could be a universal regulator of metabolic activity across the biosphere, with mitochondria in all organisms tuned to respond to the same infrared wavelengths present in Earth’s solar photon field.

What Makes This Hypothesis Different

Earlier theories proposed infrared light works by activating a photoreceptor in cytochrome c oxidase (complex IV) or by reducing water viscosity around ATP synthase motors.

Seheult’s team doesn’t reject these mechanisms—but argues they’re incomplete.

The Marcus framework explains phenomena earlier models couldn’t: why some infrared wavelengths inhibit rather than enhance mitochondrial activity, why broadband light outperforms monochromatic sources, and why effects persist across vastly different organisms.

The paper is the first to integrate four separate literature streams:

• Mitochondrial electron transfer follows Marcus physics
• Red and near-infrared light alter mitochondrial function
• Water and protein structures affect electron transfer kinetics
• Infrared radiation changes molecular electron transfer rates

“The novelty lies in the mechanistic integration,” Seheult emphasizes, “not in any single component.”

What Comes Next

The hypothesis is testable. Future experiments could measure how different infrared wavelengths alter specific Marcus crossing configurations in isolated mitochondrial complexes, or track real-time changes in reorganization energy using advanced spectroscopy.

If validated, the implications extend far beyond biology. Urban planning, architecture, workplace design, and lighting standards may all need reconsideration.

Seheult introduces a new term: photometabolism—solar-driven, non-photosynthetic modulation of core metabolic processes.

It’s a concept that positions sunlight not as a passive environmental factor, but as an active participant in the biochemistry of life itself.

I believe that this hypothesis if true has major implications for the built environment and how we live and the type of light that we require to live, and I believe it’s one of the major reasons why we need to be treating our patients outside.

Sources

• Jeffery et al. (2025) – Longer wavelengths in sunlight penetrating human tissue
• Ma et al. (2018) – Infrared perturbation of charge separation and recombination
• Sanderson et al. (2018) – Inhibitory modulation of cytochrome c oxidase with near-infrared wavelengths
• Dai et al. (2026) – Infrared stimulation of mitochondrial metabolism in deep-sea yeast
• Hayashi et al. (2010) – Water-mediated electron transfer in iron-sulfur bridges
• Marcus and Sutin (1985) – Electron transfer reactions in chemistry

Death rates from heart disease, cancer, stroke, Alzheimer’s, diabetes, and respiratory illness all peak one to three weeks after the shortest day of the year and bottom out after the longest day.

This pattern holds across both infectious and non-infectious causes. The seasonal variation in heart disease deaths alone exceeds total influenza deaths during flu season.

Australia shows the same pattern, but shifted six months—deaths peak in July, their winter. Singapore, 80 miles from the equator with year-round sun, shows no seasonal mortality pattern.

Multiple studies have linked mortality rates to latitude, independent of vitamin D levels, suggesting sunlight itself—particularly its infrared component—plays a direct metabolic role.

Hospitals Are Bringing Patients Outside

Armed with mounting evidence, hospitals worldwide are redesigning care spaces to maximize sunlight exposure.

A $1.5 billion hospital in Footscray, Australia, built ICU beds with direct outdoor access. King’s College Hospital in London invested £2 million to transform its rooftop into a critical care garden where up to six ICU patients can receive treatment surrounded by greenery and natural light.

St. George’s Hospital in London followed suit, creating a neurointensive care rooftop unit. Queen Camilla visited the facility in 2026 to recognize the innovation.

Randomized controlled trials using infrared vests delivering roughly 20–30 watts per square meter (comparable to sitting under a tree) showed 30% reductions in ICU length of stay and improved muscle strength in critically ill COVID-19 patients.

Metabolic Scaling Matches Solar Power Scaling

One of the paper’s most intriguing observations: metabolic rate scales with body mass to the 3/4 power across species from flies to elephants.

Solar power intercepted by an organism also scales to the 3/4 power of mass—nearly identical.

This doesn’t prove causation, but it suggests sunlight could be a universal regulator of metabolic activity across the biosphere, with mitochondria in all organisms tuned to respond to the same infrared wavelengths present in Earth’s solar photon field.

What Makes This Hypothesis Different

Earlier theories proposed infrared light works by activating a photoreceptor in cytochrome c oxidase (complex IV) or by reducing water viscosity around ATP synthase motors.

Seheult’s team doesn’t reject these mechanisms—but argues they’re incomplete.

The Marcus framework explains phenomena earlier models couldn’t: why some infrared wavelengths inhibit rather than enhance mitochondrial activity, why broadband light outperforms monochromatic sources, and why effects persist across vastly different organisms.

The paper is the first to integrate four separate literature streams:

• Mitochondrial electron transfer follows Marcus physics
• Red and near-infrared light alter mitochondrial function
• Water and protein structures affect electron transfer kinetics
• Infrared radiation changes molecular electron transfer rates

“The novelty lies in the mechanistic integration,” Seheult emphasizes, “not in any single component.”

What Comes Next

The hypothesis is testable. Future experiments could measure how different infrared wavelengths alter specific Marcus crossing configurations in isolated mitochondrial complexes, or track real-time changes in reorganization energy using advanced spectroscopy.

If validated, the implications extend far beyond biology. Urban planning, architecture, workplace design, and lighting standards may all need reconsideration.

Seheult introduces a new term: photometabolism—solar-driven, non-photosynthetic modulation of core metabolic processes.

It’s a concept that positions sunlight not as a passive environmental factor, but as an active participant in the biochemistry of life itself.

I believe that this hypothesis if true has major implications for the built environment and how we live and the type of light that we require to live, and I believe it’s one of the major reasons why we need to be treating our patients outside.

Sources

• Jeffery et al. (2025) – Longer wavelengths in sunlight penetrating human tissue
• Ma et al. (2018) – Infrared perturbation of charge separation and recombination
• Sanderson et al. (2018) – Inhibitory modulation of cytochrome c oxidase with near-infrared wavelengths
• Dai et al. (2026) – Infrared stimulation of mitochondrial metabolism in deep-sea yeast
• Hayashi et al. (2010) – Water-mediated electron transfer in iron-sulfur bridges
• Marcus and Sutin (1985) – Electron transfer reactions in chemistry

Seasonal Mortality Patterns Point to Sunlight’s Role

Death rates from heart disease, cancer, stroke, Alzheimer’s, diabetes, and respiratory illness all peak one to three weeks after the shortest day of the year and bottom out after the longest day.

This pattern holds across both infectious and non-infectious causes. The seasonal variation in heart disease deaths alone exceeds total influenza deaths during flu season.

Australia shows the same pattern, but shifted six months—deaths peak in July, their winter. Singapore, 80 miles from the equator with year-round sun, shows no seasonal mortality pattern.

Multiple studies have linked mortality rates to latitude, independent of vitamin D levels, suggesting sunlight itself—particularly its infrared component—plays a direct metabolic role.

Hospitals Are Bringing Patients Outside

Armed with mounting evidence, hospitals worldwide are redesigning care spaces to maximize sunlight exposure.

A $1.5 billion hospital in Footscray, Australia, built ICU beds with direct outdoor access. King’s College Hospital in London invested £2 million to transform its rooftop into a critical care garden where up to six ICU patients can receive treatment surrounded by greenery and natural light.

St. George’s Hospital in London followed suit, creating a neurointensive care rooftop unit. Queen Camilla visited the facility in 2026 to recognize the innovation.

Randomized controlled trials using infrared vests delivering roughly 20–30 watts per square meter (comparable to sitting under a tree) showed 30% reductions in ICU length of stay and improved muscle strength in critically ill COVID-19 patients.

Metabolic Scaling Matches Solar Power Scaling

One of the paper’s most intriguing observations: metabolic rate scales with body mass to the 3/4 power across species from flies to elephants.

Solar power intercepted by an organism also scales to the 3/4 power of mass—nearly identical.

This doesn’t prove causation, but it suggests sunlight could be a universal regulator of metabolic activity across the biosphere, with mitochondria in all organisms tuned to respond to the same infrared wavelengths present in Earth’s solar photon field.

What Makes This Hypothesis Different

Earlier theories proposed infrared light works by activating a photoreceptor in cytochrome c oxidase (complex IV) or by reducing water viscosity around ATP synthase motors.

Seheult’s team doesn’t reject these mechanisms—but argues they’re incomplete.

The Marcus framework explains phenomena earlier models couldn’t: why some infrared wavelengths inhibit rather than enhance mitochondrial activity, why broadband light outperforms monochromatic sources, and why effects persist across vastly different organisms.

The paper is the first to integrate four separate literature streams:

• Mitochondrial electron transfer follows Marcus physics
• Red and near-infrared light alter mitochondrial function
• Water and protein structures affect electron transfer kinetics
• Infrared radiation changes molecular electron transfer rates

“The novelty lies in the mechanistic integration,” Seheult emphasizes, “not in any single component.”

What Comes Next

The hypothesis is testable. Future experiments could measure how different infrared wavelengths alter specific Marcus crossing configurations in isolated mitochondrial complexes, or track real-time changes in reorganization energy using advanced spectroscopy.

If validated, the implications extend far beyond biology. Urban planning, architecture, workplace design, and lighting standards may all need reconsideration.

Seheult introduces a new term: photometabolism—solar-driven, non-photosynthetic modulation of core metabolic processes.

It’s a concept that positions sunlight not as a passive environmental factor, but as an active participant in the biochemistry of life itself.

I believe that this hypothesis if true has major implications for the built environment and how we live and the type of light that we require to live, and I believe it’s one of the major reasons why we need to be treating our patients outside.

Sources

• Jeffery et al. (2025) – Longer wavelengths in sunlight penetrating human tissue
• Ma et al. (2018) – Infrared perturbation of charge separation and recombination
• Sanderson et al. (2018) – Inhibitory modulation of cytochrome c oxidase with near-infrared wavelengths
• Dai et al. (2026) – Infrared stimulation of mitochondrial metabolism in deep-sea yeast
• Hayashi et al. (2010) – Water-mediated electron transfer in iron-sulfur bridges
• Marcus and Sutin (1985) – Electron transfer reactions in chemistry

Seasonal Mortality Patterns Point to Sunlight’s Role

Death rates from heart disease, cancer, stroke, Alzheimer’s, diabetes, and respiratory illness all peak one to three weeks after the shortest day of the year and bottom out after the longest day.

This pattern holds across both infectious and non-infectious causes. The seasonal variation in heart disease deaths alone exceeds total influenza deaths during flu season.

Australia shows the same pattern, but shifted six months—deaths peak in July, their winter. Singapore, 80 miles from the equator with year-round sun, shows no seasonal mortality pattern.

Multiple studies have linked mortality rates to latitude, independent of vitamin D levels, suggesting sunlight itself—particularly its infrared component—plays a direct metabolic role.

Hospitals Are Bringing Patients Outside

Armed with mounting evidence, hospitals worldwide are redesigning care spaces to maximize sunlight exposure.

A $1.5 billion hospital in Footscray, Australia, built ICU beds with direct outdoor access. King’s College Hospital in London invested £2 million to transform its rooftop into a critical care garden where up to six ICU patients can receive treatment surrounded by greenery and natural light.

St. George’s Hospital in London followed suit, creating a neurointensive care rooftop unit. Queen Camilla visited the facility in 2026 to recognize the innovation.

Randomized controlled trials using infrared vests delivering roughly 20–30 watts per square meter (comparable to sitting under a tree) showed 30% reductions in ICU length of stay and improved muscle strength in critically ill COVID-19 patients.

Metabolic Scaling Matches Solar Power Scaling

One of the paper’s most intriguing observations: metabolic rate scales with body mass to the 3/4 power across species from flies to elephants.

Solar power intercepted by an organism also scales to the 3/4 power of mass—nearly identical.

This doesn’t prove causation, but it suggests sunlight could be a universal regulator of metabolic activity across the biosphere, with mitochondria in all organisms tuned to respond to the same infrared wavelengths present in Earth’s solar photon field.

What Makes This Hypothesis Different

Earlier theories proposed infrared light works by activating a photoreceptor in cytochrome c oxidase (complex IV) or by reducing water viscosity around ATP synthase motors.

Seheult’s team doesn’t reject these mechanisms—but argues they’re incomplete.

The Marcus framework explains phenomena earlier models couldn’t: why some infrared wavelengths inhibit rather than enhance mitochondrial activity, why broadband light outperforms monochromatic sources, and why effects persist across vastly different organisms.

The paper is the first to integrate four separate literature streams:

• Mitochondrial electron transfer follows Marcus physics
• Red and near-infrared light alter mitochondrial function
• Water and protein structures affect electron transfer kinetics
• Infrared radiation changes molecular electron transfer rates

“The novelty lies in the mechanistic integration,” Seheult emphasizes, “not in any single component.”

What Comes Next

The hypothesis is testable. Future experiments could measure how different infrared wavelengths alter specific Marcus crossing configurations in isolated mitochondrial complexes, or track real-time changes in reorganization energy using advanced spectroscopy.

If validated, the implications extend far beyond biology. Urban planning, architecture, workplace design, and lighting standards may all need reconsideration.

Seheult introduces a new term: photometabolism—solar-driven, non-photosynthetic modulation of core metabolic processes.

It’s a concept that positions sunlight not as a passive environmental factor, but as an active participant in the biochemistry of life itself.

I believe that this hypothesis if true has major implications for the built environment and how we live and the type of light that we require to live, and I believe it’s one of the major reasons why we need to be treating our patients outside.

Sources

• Jeffery et al. (2025) – Longer wavelengths in sunlight penetrating human tissue
• Ma et al. (2018) – Infrared perturbation of charge separation and recombination
• Sanderson et al. (2018) – Inhibitory modulation of cytochrome c oxidase with near-infrared wavelengths
• Dai et al. (2026) – Infrared stimulation of mitochondrial metabolism in deep-sea yeast
• Hayashi et al. (2010) – Water-mediated electron transfer in iron-sulfur bridges
• Marcus and Sutin (1985) – Electron transfer reactions in chemistry

This raises profound questions about whether chronic infrared deficiency could contribute to the rising burden of metabolic diseases, especially among populations spending most of their time indoors.

Seasonal Mortality Patterns Point to Sunlight’s Role

Death rates from heart disease, cancer, stroke, Alzheimer’s, diabetes, and respiratory illness all peak one to three weeks after the shortest day of the year and bottom out after the longest day.

This pattern holds across both infectious and non-infectious causes. The seasonal variation in heart disease deaths alone exceeds total influenza deaths during flu season.

Australia shows the same pattern, but shifted six months—deaths peak in July, their winter. Singapore, 80 miles from the equator with year-round sun, shows no seasonal mortality pattern.

Multiple studies have linked mortality rates to latitude, independent of vitamin D levels, suggesting sunlight itself—particularly its infrared component—plays a direct metabolic role.

Hospitals Are Bringing Patients Outside

Armed with mounting evidence, hospitals worldwide are redesigning care spaces to maximize sunlight exposure.

A $1.5 billion hospital in Footscray, Australia, built ICU beds with direct outdoor access. King’s College Hospital in London invested £2 million to transform its rooftop into a critical care garden where up to six ICU patients can receive treatment surrounded by greenery and natural light.

St. George’s Hospital in London followed suit, creating a neurointensive care rooftop unit. Queen Camilla visited the facility in 2026 to recognize the innovation.

Randomized controlled trials using infrared vests delivering roughly 20–30 watts per square meter (comparable to sitting under a tree) showed 30% reductions in ICU length of stay and improved muscle strength in critically ill COVID-19 patients.

Metabolic Scaling Matches Solar Power Scaling

One of the paper’s most intriguing observations: metabolic rate scales with body mass to the 3/4 power across species from flies to elephants.

Solar power intercepted by an organism also scales to the 3/4 power of mass—nearly identical.

This doesn’t prove causation, but it suggests sunlight could be a universal regulator of metabolic activity across the biosphere, with mitochondria in all organisms tuned to respond to the same infrared wavelengths present in Earth’s solar photon field.

What Makes This Hypothesis Different

Earlier theories proposed infrared light works by activating a photoreceptor in cytochrome c oxidase (complex IV) or by reducing water viscosity around ATP synthase motors.

Seheult’s team doesn’t reject these mechanisms—but argues they’re incomplete.

The Marcus framework explains phenomena earlier models couldn’t: why some infrared wavelengths inhibit rather than enhance mitochondrial activity, why broadband light outperforms monochromatic sources, and why effects persist across vastly different organisms.

The paper is the first to integrate four separate literature streams:

• Mitochondrial electron transfer follows Marcus physics
• Red and near-infrared light alter mitochondrial function
• Water and protein structures affect electron transfer kinetics
• Infrared radiation changes molecular electron transfer rates

“The novelty lies in the mechanistic integration,” Seheult emphasizes, “not in any single component.”

What Comes Next

The hypothesis is testable. Future experiments could measure how different infrared wavelengths alter specific Marcus crossing configurations in isolated mitochondrial complexes, or track real-time changes in reorganization energy using advanced spectroscopy.

If validated, the implications extend far beyond biology. Urban planning, architecture, workplace design, and lighting standards may all need reconsideration.

Seheult introduces a new term: photometabolism—solar-driven, non-photosynthetic modulation of core metabolic processes.

It’s a concept that positions sunlight not as a passive environmental factor, but as an active participant in the biochemistry of life itself.

I believe that this hypothesis if true has major implications for the built environment and how we live and the type of light that we require to live, and I believe it’s one of the major reasons why we need to be treating our patients outside.

Sources

• Jeffery et al. (2025) – Longer wavelengths in sunlight penetrating human tissue
• Ma et al. (2018) – Infrared perturbation of charge separation and recombination
• Sanderson et al. (2018) – Inhibitory modulation of cytochrome c oxidase with near-infrared wavelengths
• Dai et al. (2026) – Infrared stimulation of mitochondrial metabolism in deep-sea yeast
• Hayashi et al. (2010) – Water-mediated electron transfer in iron-sulfur bridges
• Marcus and Sutin (1985) – Electron transfer reactions in chemistry

This raises profound questions about whether chronic infrared deficiency could contribute to the rising burden of metabolic diseases, especially among populations spending most of their time indoors.

Seasonal Mortality Patterns Point to Sunlight’s Role

Death rates from heart disease, cancer, stroke, Alzheimer’s, diabetes, and respiratory illness all peak one to three weeks after the shortest day of the year and bottom out after the longest day.

This pattern holds across both infectious and non-infectious causes. The seasonal variation in heart disease deaths alone exceeds total influenza deaths during flu season.

Australia shows the same pattern, but shifted six months—deaths peak in July, their winter. Singapore, 80 miles from the equator with year-round sun, shows no seasonal mortality pattern.

Multiple studies have linked mortality rates to latitude, independent of vitamin D levels, suggesting sunlight itself—particularly its infrared component—plays a direct metabolic role.

Hospitals Are Bringing Patients Outside

Armed with mounting evidence, hospitals worldwide are redesigning care spaces to maximize sunlight exposure.

A $1.5 billion hospital in Footscray, Australia, built ICU beds with direct outdoor access. King’s College Hospital in London invested £2 million to transform its rooftop into a critical care garden where up to six ICU patients can receive treatment surrounded by greenery and natural light.

St. George’s Hospital in London followed suit, creating a neurointensive care rooftop unit. Queen Camilla visited the facility in 2026 to recognize the innovation.

Randomized controlled trials using infrared vests delivering roughly 20–30 watts per square meter (comparable to sitting under a tree) showed 30% reductions in ICU length of stay and improved muscle strength in critically ill COVID-19 patients.

Metabolic Scaling Matches Solar Power Scaling

One of the paper’s most intriguing observations: metabolic rate scales with body mass to the 3/4 power across species from flies to elephants.

Solar power intercepted by an organism also scales to the 3/4 power of mass—nearly identical.

This doesn’t prove causation, but it suggests sunlight could be a universal regulator of metabolic activity across the biosphere, with mitochondria in all organisms tuned to respond to the same infrared wavelengths present in Earth’s solar photon field.

What Makes This Hypothesis Different

Earlier theories proposed infrared light works by activating a photoreceptor in cytochrome c oxidase (complex IV) or by reducing water viscosity around ATP synthase motors.

Seheult’s team doesn’t reject these mechanisms—but argues they’re incomplete.

The Marcus framework explains phenomena earlier models couldn’t: why some infrared wavelengths inhibit rather than enhance mitochondrial activity, why broadband light outperforms monochromatic sources, and why effects persist across vastly different organisms.

The paper is the first to integrate four separate literature streams:

• Mitochondrial electron transfer follows Marcus physics
• Red and near-infrared light alter mitochondrial function
• Water and protein structures affect electron transfer kinetics
• Infrared radiation changes molecular electron transfer rates

“The novelty lies in the mechanistic integration,” Seheult emphasizes, “not in any single component.”

What Comes Next

The hypothesis is testable. Future experiments could measure how different infrared wavelengths alter specific Marcus crossing configurations in isolated mitochondrial complexes, or track real-time changes in reorganization energy using advanced spectroscopy.

If validated, the implications extend far beyond biology. Urban planning, architecture, workplace design, and lighting standards may all need reconsideration.

Seheult introduces a new term: photometabolism—solar-driven, non-photosynthetic modulation of core metabolic processes.

It’s a concept that positions sunlight not as a passive environmental factor, but as an active participant in the biochemistry of life itself.

I believe that this hypothesis if true has major implications for the built environment and how we live and the type of light that we require to live, and I believe it’s one of the major reasons why we need to be treating our patients outside.

Sources

• Jeffery et al. (2025) – Longer wavelengths in sunlight penetrating human tissue
• Ma et al. (2018) – Infrared perturbation of charge separation and recombination
• Sanderson et al. (2018) – Inhibitory modulation of cytochrome c oxidase with near-infrared wavelengths
• Dai et al. (2026) – Infrared stimulation of mitochondrial metabolism in deep-sea yeast
• Hayashi et al. (2010) – Water-mediated electron transfer in iron-sulfur bridges
• Marcus and Sutin (1985) – Electron transfer reactions in chemistry

We have set up a situation where outdoors we’re getting plenty of infrared light, versus being indoors where we have Low-E glass blocking it and LED bulbs producing none.

This raises profound questions about whether chronic infrared deficiency could contribute to the rising burden of metabolic diseases, especially among populations spending most of their time indoors.

Seasonal Mortality Patterns Point to Sunlight’s Role

Death rates from heart disease, cancer, stroke, Alzheimer’s, diabetes, and respiratory illness all peak one to three weeks after the shortest day of the year and bottom out after the longest day.

This pattern holds across both infectious and non-infectious causes. The seasonal variation in heart disease deaths alone exceeds total influenza deaths during flu season.

Australia shows the same pattern, but shifted six months—deaths peak in July, their winter. Singapore, 80 miles from the equator with year-round sun, shows no seasonal mortality pattern.

Multiple studies have linked mortality rates to latitude, independent of vitamin D levels, suggesting sunlight itself—particularly its infrared component—plays a direct metabolic role.

Hospitals Are Bringing Patients Outside

Armed with mounting evidence, hospitals worldwide are redesigning care spaces to maximize sunlight exposure.

A $1.5 billion hospital in Footscray, Australia, built ICU beds with direct outdoor access. King’s College Hospital in London invested £2 million to transform its rooftop into a critical care garden where up to six ICU patients can receive treatment surrounded by greenery and natural light.

St. George’s Hospital in London followed suit, creating a neurointensive care rooftop unit. Queen Camilla visited the facility in 2026 to recognize the innovation.

Randomized controlled trials using infrared vests delivering roughly 20–30 watts per square meter (comparable to sitting under a tree) showed 30% reductions in ICU length of stay and improved muscle strength in critically ill COVID-19 patients.

Metabolic Scaling Matches Solar Power Scaling

One of the paper’s most intriguing observations: metabolic rate scales with body mass to the 3/4 power across species from flies to elephants.

Solar power intercepted by an organism also scales to the 3/4 power of mass—nearly identical.

This doesn’t prove causation, but it suggests sunlight could be a universal regulator of metabolic activity across the biosphere, with mitochondria in all organisms tuned to respond to the same infrared wavelengths present in Earth’s solar photon field.

What Makes This Hypothesis Different

Earlier theories proposed infrared light works by activating a photoreceptor in cytochrome c oxidase (complex IV) or by reducing water viscosity around ATP synthase motors.

Seheult’s team doesn’t reject these mechanisms—but argues they’re incomplete.

The Marcus framework explains phenomena earlier models couldn’t: why some infrared wavelengths inhibit rather than enhance mitochondrial activity, why broadband light outperforms monochromatic sources, and why effects persist across vastly different organisms.

The paper is the first to integrate four separate literature streams:

• Mitochondrial electron transfer follows Marcus physics
• Red and near-infrared light alter mitochondrial function
• Water and protein structures affect electron transfer kinetics
• Infrared radiation changes molecular electron transfer rates

“The novelty lies in the mechanistic integration,” Seheult emphasizes, “not in any single component.”

What Comes Next

The hypothesis is testable. Future experiments could measure how different infrared wavelengths alter specific Marcus crossing configurations in isolated mitochondrial complexes, or track real-time changes in reorganization energy using advanced spectroscopy.

If validated, the implications extend far beyond biology. Urban planning, architecture, workplace design, and lighting standards may all need reconsideration.

Seheult introduces a new term: photometabolism—solar-driven, non-photosynthetic modulation of core metabolic processes.

It’s a concept that positions sunlight not as a passive environmental factor, but as an active participant in the biochemistry of life itself.

I believe that this hypothesis if true has major implications for the built environment and how we live and the type of light that we require to live, and I believe it’s one of the major reasons why we need to be treating our patients outside.

Sources

• Jeffery et al. (2025) – Longer wavelengths in sunlight penetrating human tissue
• Ma et al. (2018) – Infrared perturbation of charge separation and recombination
• Sanderson et al. (2018) – Inhibitory modulation of cytochrome c oxidase with near-infrared wavelengths
• Dai et al. (2026) – Infrared stimulation of mitochondrial metabolism in deep-sea yeast
• Hayashi et al. (2010) – Water-mediated electron transfer in iron-sulfur bridges
• Marcus and Sutin (1985) – Electron transfer reactions in chemistry

We have set up a situation where outdoors we’re getting plenty of infrared light, versus being indoors where we have Low-E glass blocking it and LED bulbs producing none.

This raises profound questions about whether chronic infrared deficiency could contribute to the rising burden of metabolic diseases, especially among populations spending most of their time indoors.

Seasonal Mortality Patterns Point to Sunlight’s Role

Death rates from heart disease, cancer, stroke, Alzheimer’s, diabetes, and respiratory illness all peak one to three weeks after the shortest day of the year and bottom out after the longest day.

This pattern holds across both infectious and non-infectious causes. The seasonal variation in heart disease deaths alone exceeds total influenza deaths during flu season.

Australia shows the same pattern, but shifted six months—deaths peak in July, their winter. Singapore, 80 miles from the equator with year-round sun, shows no seasonal mortality pattern.

Multiple studies have linked mortality rates to latitude, independent of vitamin D levels, suggesting sunlight itself—particularly its infrared component—plays a direct metabolic role.

Hospitals Are Bringing Patients Outside

Armed with mounting evidence, hospitals worldwide are redesigning care spaces to maximize sunlight exposure.

A $1.5 billion hospital in Footscray, Australia, built ICU beds with direct outdoor access. King’s College Hospital in London invested £2 million to transform its rooftop into a critical care garden where up to six ICU patients can receive treatment surrounded by greenery and natural light.

St. George’s Hospital in London followed suit, creating a neurointensive care rooftop unit. Queen Camilla visited the facility in 2026 to recognize the innovation.

Randomized controlled trials using infrared vests delivering roughly 20–30 watts per square meter (comparable to sitting under a tree) showed 30% reductions in ICU length of stay and improved muscle strength in critically ill COVID-19 patients.

Metabolic Scaling Matches Solar Power Scaling

One of the paper’s most intriguing observations: metabolic rate scales with body mass to the 3/4 power across species from flies to elephants.

Solar power intercepted by an organism also scales to the 3/4 power of mass—nearly identical.

This doesn’t prove causation, but it suggests sunlight could be a universal regulator of metabolic activity across the biosphere, with mitochondria in all organisms tuned to respond to the same infrared wavelengths present in Earth’s solar photon field.

What Makes This Hypothesis Different

Earlier theories proposed infrared light works by activating a photoreceptor in cytochrome c oxidase (complex IV) or by reducing water viscosity around ATP synthase motors.

Seheult’s team doesn’t reject these mechanisms—but argues they’re incomplete.

The Marcus framework explains phenomena earlier models couldn’t: why some infrared wavelengths inhibit rather than enhance mitochondrial activity, why broadband light outperforms monochromatic sources, and why effects persist across vastly different organisms.

The paper is the first to integrate four separate literature streams:

• Mitochondrial electron transfer follows Marcus physics
• Red and near-infrared light alter mitochondrial function
• Water and protein structures affect electron transfer kinetics
• Infrared radiation changes molecular electron transfer rates

“The novelty lies in the mechanistic integration,” Seheult emphasizes, “not in any single component.”

What Comes Next

The hypothesis is testable. Future experiments could measure how different infrared wavelengths alter specific Marcus crossing configurations in isolated mitochondrial complexes, or track real-time changes in reorganization energy using advanced spectroscopy.

If validated, the implications extend far beyond biology. Urban planning, architecture, workplace design, and lighting standards may all need reconsideration.

Seheult introduces a new term: photometabolism—solar-driven, non-photosynthetic modulation of core metabolic processes.

It’s a concept that positions sunlight not as a passive environmental factor, but as an active participant in the biochemistry of life itself.

I believe that this hypothesis if true has major implications for the built environment and how we live and the type of light that we require to live, and I believe it’s one of the major reasons why we need to be treating our patients outside.

Sources

• Jeffery et al. (2025) – Longer wavelengths in sunlight penetrating human tissue
• Ma et al. (2018) – Infrared perturbation of charge separation and recombination
• Sanderson et al. (2018) – Inhibitory modulation of cytochrome c oxidase with near-infrared wavelengths
• Dai et al. (2026) – Infrared stimulation of mitochondrial metabolism in deep-sea yeast
• Hayashi et al. (2010) – Water-mediated electron transfer in iron-sulfur bridges
• Marcus and Sutin (1985) – Electron transfer reactions in chemistry

Step outside under a shade tree with grass reflecting sunlight? 41.9 watts per square meter—more than 50 times higher.

We have set up a situation where outdoors we’re getting plenty of infrared light, versus being indoors where we have Low-E glass blocking it and LED bulbs producing none.

This raises profound questions about whether chronic infrared deficiency could contribute to the rising burden of metabolic diseases, especially among populations spending most of their time indoors.

Seasonal Mortality Patterns Point to Sunlight’s Role

Death rates from heart disease, cancer, stroke, Alzheimer’s, diabetes, and respiratory illness all peak one to three weeks after the shortest day of the year and bottom out after the longest day.

This pattern holds across both infectious and non-infectious causes. The seasonal variation in heart disease deaths alone exceeds total influenza deaths during flu season.

Australia shows the same pattern, but shifted six months—deaths peak in July, their winter. Singapore, 80 miles from the equator with year-round sun, shows no seasonal mortality pattern.

Multiple studies have linked mortality rates to latitude, independent of vitamin D levels, suggesting sunlight itself—particularly its infrared component—plays a direct metabolic role.

Hospitals Are Bringing Patients Outside

Armed with mounting evidence, hospitals worldwide are redesigning care spaces to maximize sunlight exposure.

A $1.5 billion hospital in Footscray, Australia, built ICU beds with direct outdoor access. King’s College Hospital in London invested £2 million to transform its rooftop into a critical care garden where up to six ICU patients can receive treatment surrounded by greenery and natural light.

St. George’s Hospital in London followed suit, creating a neurointensive care rooftop unit. Queen Camilla visited the facility in 2026 to recognize the innovation.

Randomized controlled trials using infrared vests delivering roughly 20–30 watts per square meter (comparable to sitting under a tree) showed 30% reductions in ICU length of stay and improved muscle strength in critically ill COVID-19 patients.

Metabolic Scaling Matches Solar Power Scaling

One of the paper’s most intriguing observations: metabolic rate scales with body mass to the 3/4 power across species from flies to elephants.

Solar power intercepted by an organism also scales to the 3/4 power of mass—nearly identical.

This doesn’t prove causation, but it suggests sunlight could be a universal regulator of metabolic activity across the biosphere, with mitochondria in all organisms tuned to respond to the same infrared wavelengths present in Earth’s solar photon field.

What Makes This Hypothesis Different

Earlier theories proposed infrared light works by activating a photoreceptor in cytochrome c oxidase (complex IV) or by reducing water viscosity around ATP synthase motors.

Seheult’s team doesn’t reject these mechanisms—but argues they’re incomplete.

The Marcus framework explains phenomena earlier models couldn’t: why some infrared wavelengths inhibit rather than enhance mitochondrial activity, why broadband light outperforms monochromatic sources, and why effects persist across vastly different organisms.

The paper is the first to integrate four separate literature streams:

• Mitochondrial electron transfer follows Marcus physics
• Red and near-infrared light alter mitochondrial function
• Water and protein structures affect electron transfer kinetics
• Infrared radiation changes molecular electron transfer rates

“The novelty lies in the mechanistic integration,” Seheult emphasizes, “not in any single component.”

What Comes Next

The hypothesis is testable. Future experiments could measure how different infrared wavelengths alter specific Marcus crossing configurations in isolated mitochondrial complexes, or track real-time changes in reorganization energy using advanced spectroscopy.

If validated, the implications extend far beyond biology. Urban planning, architecture, workplace design, and lighting standards may all need reconsideration.

Seheult introduces a new term: photometabolism—solar-driven, non-photosynthetic modulation of core metabolic processes.

It’s a concept that positions sunlight not as a passive environmental factor, but as an active participant in the biochemistry of life itself.

I believe that this hypothesis if true has major implications for the built environment and how we live and the type of light that we require to live, and I believe it’s one of the major reasons why we need to be treating our patients outside.

Sources

• Jeffery et al. (2025) – Longer wavelengths in sunlight penetrating human tissue
• Ma et al. (2018) – Infrared perturbation of charge separation and recombination
• Sanderson et al. (2018) – Inhibitory modulation of cytochrome c oxidase with near-infrared wavelengths
• Dai et al. (2026) – Infrared stimulation of mitochondrial metabolism in deep-sea yeast
• Hayashi et al. (2010) – Water-mediated electron transfer in iron-sulfur bridges
• Marcus and Sutin (1985) – Electron transfer reactions in chemistry

Step outside under a shade tree with grass reflecting sunlight? 41.9 watts per square meter—more than 50 times higher.

We have set up a situation where outdoors we’re getting plenty of infrared light, versus being indoors where we have Low-E glass blocking it and LED bulbs producing none.

This raises profound questions about whether chronic infrared deficiency could contribute to the rising burden of metabolic diseases, especially among populations spending most of their time indoors.

Seasonal Mortality Patterns Point to Sunlight’s Role

Death rates from heart disease, cancer, stroke, Alzheimer’s, diabetes, and respiratory illness all peak one to three weeks after the shortest day of the year and bottom out after the longest day.

This pattern holds across both infectious and non-infectious causes. The seasonal variation in heart disease deaths alone exceeds total influenza deaths during flu season.

Australia shows the same pattern, but shifted six months—deaths peak in July, their winter. Singapore, 80 miles from the equator with year-round sun, shows no seasonal mortality pattern.

Multiple studies have linked mortality rates to latitude, independent of vitamin D levels, suggesting sunlight itself—particularly its infrared component—plays a direct metabolic role.

Hospitals Are Bringing Patients Outside

Armed with mounting evidence, hospitals worldwide are redesigning care spaces to maximize sunlight exposure.

A $1.5 billion hospital in Footscray, Australia, built ICU beds with direct outdoor access. King’s College Hospital in London invested £2 million to transform its rooftop into a critical care garden where up to six ICU patients can receive treatment surrounded by greenery and natural light.

St. George’s Hospital in London followed suit, creating a neurointensive care rooftop unit. Queen Camilla visited the facility in 2026 to recognize the innovation.

Randomized controlled trials using infrared vests delivering roughly 20–30 watts per square meter (comparable to sitting under a tree) showed 30% reductions in ICU length of stay and improved muscle strength in critically ill COVID-19 patients.

Metabolic Scaling Matches Solar Power Scaling

One of the paper’s most intriguing observations: metabolic rate scales with body mass to the 3/4 power across species from flies to elephants.

Solar power intercepted by an organism also scales to the 3/4 power of mass—nearly identical.

This doesn’t prove causation, but it suggests sunlight could be a universal regulator of metabolic activity across the biosphere, with mitochondria in all organisms tuned to respond to the same infrared wavelengths present in Earth’s solar photon field.

What Makes This Hypothesis Different

Earlier theories proposed infrared light works by activating a photoreceptor in cytochrome c oxidase (complex IV) or by reducing water viscosity around ATP synthase motors.

Seheult’s team doesn’t reject these mechanisms—but argues they’re incomplete.

The Marcus framework explains phenomena earlier models couldn’t: why some infrared wavelengths inhibit rather than enhance mitochondrial activity, why broadband light outperforms monochromatic sources, and why effects persist across vastly different organisms.

The paper is the first to integrate four separate literature streams:

• Mitochondrial electron transfer follows Marcus physics
• Red and near-infrared light alter mitochondrial function
• Water and protein structures affect electron transfer kinetics
• Infrared radiation changes molecular electron transfer rates

“The novelty lies in the mechanistic integration,” Seheult emphasizes, “not in any single component.”

What Comes Next

The hypothesis is testable. Future experiments could measure how different infrared wavelengths alter specific Marcus crossing configurations in isolated mitochondrial complexes, or track real-time changes in reorganization energy using advanced spectroscopy.

If validated, the implications extend far beyond biology. Urban planning, architecture, workplace design, and lighting standards may all need reconsideration.

Seheult introduces a new term: photometabolism—solar-driven, non-photosynthetic modulation of core metabolic processes.

It’s a concept that positions sunlight not as a passive environmental factor, but as an active participant in the biochemistry of life itself.

I believe that this hypothesis if true has major implications for the built environment and how we live and the type of light that we require to live, and I believe it’s one of the major reasons why we need to be treating our patients outside.

Sources

• Jeffery et al. (2025) – Longer wavelengths in sunlight penetrating human tissue
• Ma et al. (2018) – Infrared perturbation of charge separation and recombination
• Sanderson et al. (2018) – Inhibitory modulation of cytochrome c oxidase with near-infrared wavelengths
• Dai et al. (2026) – Infrared stimulation of mitochondrial metabolism in deep-sea yeast
• Hayashi et al. (2010) – Water-mediated electron transfer in iron-sulfur bridges
• Marcus and Sutin (1985) – Electron transfer reactions in chemistry

Seheult measured infrared exposure in his own dining room with windows open: 0.8 watts per square meter.

Step outside under a shade tree with grass reflecting sunlight? 41.9 watts per square meter—more than 50 times higher.

We have set up a situation where outdoors we’re getting plenty of infrared light, versus being indoors where we have Low-E glass blocking it and LED bulbs producing none.

This raises profound questions about whether chronic infrared deficiency could contribute to the rising burden of metabolic diseases, especially among populations spending most of their time indoors.

Seasonal Mortality Patterns Point to Sunlight’s Role

Death rates from heart disease, cancer, stroke, Alzheimer’s, diabetes, and respiratory illness all peak one to three weeks after the shortest day of the year and bottom out after the longest day.

This pattern holds across both infectious and non-infectious causes. The seasonal variation in heart disease deaths alone exceeds total influenza deaths during flu season.

Australia shows the same pattern, but shifted six months—deaths peak in July, their winter. Singapore, 80 miles from the equator with year-round sun, shows no seasonal mortality pattern.

Multiple studies have linked mortality rates to latitude, independent of vitamin D levels, suggesting sunlight itself—particularly its infrared component—plays a direct metabolic role.

Hospitals Are Bringing Patients Outside

Armed with mounting evidence, hospitals worldwide are redesigning care spaces to maximize sunlight exposure.

A $1.5 billion hospital in Footscray, Australia, built ICU beds with direct outdoor access. King’s College Hospital in London invested £2 million to transform its rooftop into a critical care garden where up to six ICU patients can receive treatment surrounded by greenery and natural light.

St. George’s Hospital in London followed suit, creating a neurointensive care rooftop unit. Queen Camilla visited the facility in 2026 to recognize the innovation.

Randomized controlled trials using infrared vests delivering roughly 20–30 watts per square meter (comparable to sitting under a tree) showed 30% reductions in ICU length of stay and improved muscle strength in critically ill COVID-19 patients.

Metabolic Scaling Matches Solar Power Scaling

One of the paper’s most intriguing observations: metabolic rate scales with body mass to the 3/4 power across species from flies to elephants.

Solar power intercepted by an organism also scales to the 3/4 power of mass—nearly identical.

This doesn’t prove causation, but it suggests sunlight could be a universal regulator of metabolic activity across the biosphere, with mitochondria in all organisms tuned to respond to the same infrared wavelengths present in Earth’s solar photon field.

What Makes This Hypothesis Different

Earlier theories proposed infrared light works by activating a photoreceptor in cytochrome c oxidase (complex IV) or by reducing water viscosity around ATP synthase motors.

Seheult’s team doesn’t reject these mechanisms—but argues they’re incomplete.

The Marcus framework explains phenomena earlier models couldn’t: why some infrared wavelengths inhibit rather than enhance mitochondrial activity, why broadband light outperforms monochromatic sources, and why effects persist across vastly different organisms.

The paper is the first to integrate four separate literature streams:

• Mitochondrial electron transfer follows Marcus physics
• Red and near-infrared light alter mitochondrial function
• Water and protein structures affect electron transfer kinetics
• Infrared radiation changes molecular electron transfer rates

“The novelty lies in the mechanistic integration,” Seheult emphasizes, “not in any single component.”

What Comes Next

The hypothesis is testable. Future experiments could measure how different infrared wavelengths alter specific Marcus crossing configurations in isolated mitochondrial complexes, or track real-time changes in reorganization energy using advanced spectroscopy.

If validated, the implications extend far beyond biology. Urban planning, architecture, workplace design, and lighting standards may all need reconsideration.

Seheult introduces a new term: photometabolism—solar-driven, non-photosynthetic modulation of core metabolic processes.

It’s a concept that positions sunlight not as a passive environmental factor, but as an active participant in the biochemistry of life itself.

I believe that this hypothesis if true has major implications for the built environment and how we live and the type of light that we require to live, and I believe it’s one of the major reasons why we need to be treating our patients outside.

Sources

• Jeffery et al. (2025) – Longer wavelengths in sunlight penetrating human tissue
• Ma et al. (2018) – Infrared perturbation of charge separation and recombination
• Sanderson et al. (2018) – Inhibitory modulation of cytochrome c oxidase with near-infrared wavelengths
• Dai et al. (2026) – Infrared stimulation of mitochondrial metabolism in deep-sea yeast
• Hayashi et al. (2010) – Water-mediated electron transfer in iron-sulfur bridges
• Marcus and Sutin (1985) – Electron transfer reactions in chemistry

Seheult measured infrared exposure in his own dining room with windows open: 0.8 watts per square meter.

Step outside under a shade tree with grass reflecting sunlight? 41.9 watts per square meter—more than 50 times higher.

We have set up a situation where outdoors we’re getting plenty of infrared light, versus being indoors where we have Low-E glass blocking it and LED bulbs producing none.

This raises profound questions about whether chronic infrared deficiency could contribute to the rising burden of metabolic diseases, especially among populations spending most of their time indoors.

Seasonal Mortality Patterns Point to Sunlight’s Role

Death rates from heart disease, cancer, stroke, Alzheimer’s, diabetes, and respiratory illness all peak one to three weeks after the shortest day of the year and bottom out after the longest day.

This pattern holds across both infectious and non-infectious causes. The seasonal variation in heart disease deaths alone exceeds total influenza deaths during flu season.

Australia shows the same pattern, but shifted six months—deaths peak in July, their winter. Singapore, 80 miles from the equator with year-round sun, shows no seasonal mortality pattern.

Multiple studies have linked mortality rates to latitude, independent of vitamin D levels, suggesting sunlight itself—particularly its infrared component—plays a direct metabolic role.

Hospitals Are Bringing Patients Outside

Armed with mounting evidence, hospitals worldwide are redesigning care spaces to maximize sunlight exposure.

A $1.5 billion hospital in Footscray, Australia, built ICU beds with direct outdoor access. King’s College Hospital in London invested £2 million to transform its rooftop into a critical care garden where up to six ICU patients can receive treatment surrounded by greenery and natural light.

St. George’s Hospital in London followed suit, creating a neurointensive care rooftop unit. Queen Camilla visited the facility in 2026 to recognize the innovation.

Randomized controlled trials using infrared vests delivering roughly 20–30 watts per square meter (comparable to sitting under a tree) showed 30% reductions in ICU length of stay and improved muscle strength in critically ill COVID-19 patients.

Metabolic Scaling Matches Solar Power Scaling

One of the paper’s most intriguing observations: metabolic rate scales with body mass to the 3/4 power across species from flies to elephants.

Solar power intercepted by an organism also scales to the 3/4 power of mass—nearly identical.

This doesn’t prove causation, but it suggests sunlight could be a universal regulator of metabolic activity across the biosphere, with mitochondria in all organisms tuned to respond to the same infrared wavelengths present in Earth’s solar photon field.

What Makes This Hypothesis Different

Earlier theories proposed infrared light works by activating a photoreceptor in cytochrome c oxidase (complex IV) or by reducing water viscosity around ATP synthase motors.

Seheult’s team doesn’t reject these mechanisms—but argues they’re incomplete.

The Marcus framework explains phenomena earlier models couldn’t: why some infrared wavelengths inhibit rather than enhance mitochondrial activity, why broadband light outperforms monochromatic sources, and why effects persist across vastly different organisms.

The paper is the first to integrate four separate literature streams:

• Mitochondrial electron transfer follows Marcus physics
• Red and near-infrared light alter mitochondrial function
• Water and protein structures affect electron transfer kinetics
• Infrared radiation changes molecular electron transfer rates

“The novelty lies in the mechanistic integration,” Seheult emphasizes, “not in any single component.”

What Comes Next

The hypothesis is testable. Future experiments could measure how different infrared wavelengths alter specific Marcus crossing configurations in isolated mitochondrial complexes, or track real-time changes in reorganization energy using advanced spectroscopy.

If validated, the implications extend far beyond biology. Urban planning, architecture, workplace design, and lighting standards may all need reconsideration.

Seheult introduces a new term: photometabolism—solar-driven, non-photosynthetic modulation of core metabolic processes.

It’s a concept that positions sunlight not as a passive environmental factor, but as an active participant in the biochemistry of life itself.

I believe that this hypothesis if true has major implications for the built environment and how we live and the type of light that we require to live, and I believe it’s one of the major reasons why we need to be treating our patients outside.

Sources

• Jeffery et al. (2025) – Longer wavelengths in sunlight penetrating human tissue
• Ma et al. (2018) – Infrared perturbation of charge separation and recombination
• Sanderson et al. (2018) – Inhibitory modulation of cytochrome c oxidase with near-infrared wavelengths
• Dai et al. (2026) – Infrared stimulation of mitochondrial metabolism in deep-sea yeast
• Hayashi et al. (2010) – Water-mediated electron transfer in iron-sulfur bridges
• Marcus and Sutin (1985) – Electron transfer reactions in chemistry

LED bulbs emit virtually no infrared radiation. Low-emissivity (Low-E) glass windows, designed to improve energy efficiency, block infrared wavelengths.

Seheult measured infrared exposure in his own dining room with windows open: 0.8 watts per square meter.

Step outside under a shade tree with grass reflecting sunlight? 41.9 watts per square meter—more than 50 times higher.

We have set up a situation where outdoors we’re getting plenty of infrared light, versus being indoors where we have Low-E glass blocking it and LED bulbs producing none.

This raises profound questions about whether chronic infrared deficiency could contribute to the rising burden of metabolic diseases, especially among populations spending most of their time indoors.

Seasonal Mortality Patterns Point to Sunlight’s Role

Death rates from heart disease, cancer, stroke, Alzheimer’s, diabetes, and respiratory illness all peak one to three weeks after the shortest day of the year and bottom out after the longest day.

This pattern holds across both infectious and non-infectious causes. The seasonal variation in heart disease deaths alone exceeds total influenza deaths during flu season.

Australia shows the same pattern, but shifted six months—deaths peak in July, their winter. Singapore, 80 miles from the equator with year-round sun, shows no seasonal mortality pattern.

Multiple studies have linked mortality rates to latitude, independent of vitamin D levels, suggesting sunlight itself—particularly its infrared component—plays a direct metabolic role.

Hospitals Are Bringing Patients Outside

Armed with mounting evidence, hospitals worldwide are redesigning care spaces to maximize sunlight exposure.

A $1.5 billion hospital in Footscray, Australia, built ICU beds with direct outdoor access. King’s College Hospital in London invested £2 million to transform its rooftop into a critical care garden where up to six ICU patients can receive treatment surrounded by greenery and natural light.

St. George’s Hospital in London followed suit, creating a neurointensive care rooftop unit. Queen Camilla visited the facility in 2026 to recognize the innovation.

Randomized controlled trials using infrared vests delivering roughly 20–30 watts per square meter (comparable to sitting under a tree) showed 30% reductions in ICU length of stay and improved muscle strength in critically ill COVID-19 patients.

Metabolic Scaling Matches Solar Power Scaling

One of the paper’s most intriguing observations: metabolic rate scales with body mass to the 3/4 power across species from flies to elephants.

Solar power intercepted by an organism also scales to the 3/4 power of mass—nearly identical.

This doesn’t prove causation, but it suggests sunlight could be a universal regulator of metabolic activity across the biosphere, with mitochondria in all organisms tuned to respond to the same infrared wavelengths present in Earth’s solar photon field.

What Makes This Hypothesis Different

Earlier theories proposed infrared light works by activating a photoreceptor in cytochrome c oxidase (complex IV) or by reducing water viscosity around ATP synthase motors.

Seheult’s team doesn’t reject these mechanisms—but argues they’re incomplete.

The Marcus framework explains phenomena earlier models couldn’t: why some infrared wavelengths inhibit rather than enhance mitochondrial activity, why broadband light outperforms monochromatic sources, and why effects persist across vastly different organisms.

The paper is the first to integrate four separate literature streams:

• Mitochondrial electron transfer follows Marcus physics
• Red and near-infrared light alter mitochondrial function
• Water and protein structures affect electron transfer kinetics
• Infrared radiation changes molecular electron transfer rates

“The novelty lies in the mechanistic integration,” Seheult emphasizes, “not in any single component.”

What Comes Next

The hypothesis is testable. Future experiments could measure how different infrared wavelengths alter specific Marcus crossing configurations in isolated mitochondrial complexes, or track real-time changes in reorganization energy using advanced spectroscopy.

If validated, the implications extend far beyond biology. Urban planning, architecture, workplace design, and lighting standards may all need reconsideration.

Seheult introduces a new term: photometabolism—solar-driven, non-photosynthetic modulation of core metabolic processes.

It’s a concept that positions sunlight not as a passive environmental factor, but as an active participant in the biochemistry of life itself.

I believe that this hypothesis if true has major implications for the built environment and how we live and the type of light that we require to live, and I believe it’s one of the major reasons why we need to be treating our patients outside.

Sources

• Jeffery et al. (2025) – Longer wavelengths in sunlight penetrating human tissue
• Ma et al. (2018) – Infrared perturbation of charge separation and recombination
• Sanderson et al. (2018) – Inhibitory modulation of cytochrome c oxidase with near-infrared wavelengths
• Dai et al. (2026) – Infrared stimulation of mitochondrial metabolism in deep-sea yeast
• Hayashi et al. (2010) – Water-mediated electron transfer in iron-sulfur bridges
• Marcus and Sutin (1985) – Electron transfer reactions in chemistry

LED bulbs emit virtually no infrared radiation. Low-emissivity (Low-E) glass windows, designed to improve energy efficiency, block infrared wavelengths.

Seheult measured infrared exposure in his own dining room with windows open: 0.8 watts per square meter.

Step outside under a shade tree with grass reflecting sunlight? 41.9 watts per square meter—more than 50 times higher.

We have set up a situation where outdoors we’re getting plenty of infrared light, versus being indoors where we have Low-E glass blocking it and LED bulbs producing none.

This raises profound questions about whether chronic infrared deficiency could contribute to the rising burden of metabolic diseases, especially among populations spending most of their time indoors.

Seasonal Mortality Patterns Point to Sunlight’s Role

Death rates from heart disease, cancer, stroke, Alzheimer’s, diabetes, and respiratory illness all peak one to three weeks after the shortest day of the year and bottom out after the longest day.

This pattern holds across both infectious and non-infectious causes. The seasonal variation in heart disease deaths alone exceeds total influenza deaths during flu season.

Australia shows the same pattern, but shifted six months—deaths peak in July, their winter. Singapore, 80 miles from the equator with year-round sun, shows no seasonal mortality pattern.

Multiple studies have linked mortality rates to latitude, independent of vitamin D levels, suggesting sunlight itself—particularly its infrared component—plays a direct metabolic role.

Hospitals Are Bringing Patients Outside

Armed with mounting evidence, hospitals worldwide are redesigning care spaces to maximize sunlight exposure.

A $1.5 billion hospital in Footscray, Australia, built ICU beds with direct outdoor access. King’s College Hospital in London invested £2 million to transform its rooftop into a critical care garden where up to six ICU patients can receive treatment surrounded by greenery and natural light.

St. George’s Hospital in London followed suit, creating a neurointensive care rooftop unit. Queen Camilla visited the facility in 2026 to recognize the innovation.

Randomized controlled trials using infrared vests delivering roughly 20–30 watts per square meter (comparable to sitting under a tree) showed 30% reductions in ICU length of stay and improved muscle strength in critically ill COVID-19 patients.

Metabolic Scaling Matches Solar Power Scaling

One of the paper’s most intriguing observations: metabolic rate scales with body mass to the 3/4 power across species from flies to elephants.

Solar power intercepted by an organism also scales to the 3/4 power of mass—nearly identical.

This doesn’t prove causation, but it suggests sunlight could be a universal regulator of metabolic activity across the biosphere, with mitochondria in all organisms tuned to respond to the same infrared wavelengths present in Earth’s solar photon field.

What Makes This Hypothesis Different

Earlier theories proposed infrared light works by activating a photoreceptor in cytochrome c oxidase (complex IV) or by reducing water viscosity around ATP synthase motors.

Seheult’s team doesn’t reject these mechanisms—but argues they’re incomplete.

The Marcus framework explains phenomena earlier models couldn’t: why some infrared wavelengths inhibit rather than enhance mitochondrial activity, why broadband light outperforms monochromatic sources, and why effects persist across vastly different organisms.

The paper is the first to integrate four separate literature streams:

• Mitochondrial electron transfer follows Marcus physics
• Red and near-infrared light alter mitochondrial function
• Water and protein structures affect electron transfer kinetics
• Infrared radiation changes molecular electron transfer rates

“The novelty lies in the mechanistic integration,” Seheult emphasizes, “not in any single component.”

What Comes Next

The hypothesis is testable. Future experiments could measure how different infrared wavelengths alter specific Marcus crossing configurations in isolated mitochondrial complexes, or track real-time changes in reorganization energy using advanced spectroscopy.

If validated, the implications extend far beyond biology. Urban planning, architecture, workplace design, and lighting standards may all need reconsideration.

Seheult introduces a new term: photometabolism—solar-driven, non-photosynthetic modulation of core metabolic processes.

It’s a concept that positions sunlight not as a passive environmental factor, but as an active participant in the biochemistry of life itself.

I believe that this hypothesis if true has major implications for the built environment and how we live and the type of light that we require to live, and I believe it’s one of the major reasons why we need to be treating our patients outside.

Sources

• Jeffery et al. (2025) – Longer wavelengths in sunlight penetrating human tissue
• Ma et al. (2018) – Infrared perturbation of charge separation and recombination
• Sanderson et al. (2018) – Inhibitory modulation of cytochrome c oxidase with near-infrared wavelengths
• Dai et al. (2026) – Infrared stimulation of mitochondrial metabolism in deep-sea yeast
• Hayashi et al. (2010) – Water-mediated electron transfer in iron-sulfur bridges
• Marcus and Sutin (1985) – Electron transfer reactions in chemistry

The Modern Indoor Environment: A Metabolic Desert?

LED bulbs emit virtually no infrared radiation. Low-emissivity (Low-E) glass windows, designed to improve energy efficiency, block infrared wavelengths.

Seheult measured infrared exposure in his own dining room with windows open: 0.8 watts per square meter.

Step outside under a shade tree with grass reflecting sunlight? 41.9 watts per square meter—more than 50 times higher.

We have set up a situation where outdoors we’re getting plenty of infrared light, versus being indoors where we have Low-E glass blocking it and LED bulbs producing none.

This raises profound questions about whether chronic infrared deficiency could contribute to the rising burden of metabolic diseases, especially among populations spending most of their time indoors.

Seasonal Mortality Patterns Point to Sunlight’s Role

Death rates from heart disease, cancer, stroke, Alzheimer’s, diabetes, and respiratory illness all peak one to three weeks after the shortest day of the year and bottom out after the longest day.

This pattern holds across both infectious and non-infectious causes. The seasonal variation in heart disease deaths alone exceeds total influenza deaths during flu season.

Australia shows the same pattern, but shifted six months—deaths peak in July, their winter. Singapore, 80 miles from the equator with year-round sun, shows no seasonal mortality pattern.

Multiple studies have linked mortality rates to latitude, independent of vitamin D levels, suggesting sunlight itself—particularly its infrared component—plays a direct metabolic role.

Hospitals Are Bringing Patients Outside

Armed with mounting evidence, hospitals worldwide are redesigning care spaces to maximize sunlight exposure.

A $1.5 billion hospital in Footscray, Australia, built ICU beds with direct outdoor access. King’s College Hospital in London invested £2 million to transform its rooftop into a critical care garden where up to six ICU patients can receive treatment surrounded by greenery and natural light.

St. George’s Hospital in London followed suit, creating a neurointensive care rooftop unit. Queen Camilla visited the facility in 2026 to recognize the innovation.

Randomized controlled trials using infrared vests delivering roughly 20–30 watts per square meter (comparable to sitting under a tree) showed 30% reductions in ICU length of stay and improved muscle strength in critically ill COVID-19 patients.

Metabolic Scaling Matches Solar Power Scaling

One of the paper’s most intriguing observations: metabolic rate scales with body mass to the 3/4 power across species from flies to elephants.

Solar power intercepted by an organism also scales to the 3/4 power of mass—nearly identical.

This doesn’t prove causation, but it suggests sunlight could be a universal regulator of metabolic activity across the biosphere, with mitochondria in all organisms tuned to respond to the same infrared wavelengths present in Earth’s solar photon field.

What Makes This Hypothesis Different

Earlier theories proposed infrared light works by activating a photoreceptor in cytochrome c oxidase (complex IV) or by reducing water viscosity around ATP synthase motors.

Seheult’s team doesn’t reject these mechanisms—but argues they’re incomplete.

The Marcus framework explains phenomena earlier models couldn’t: why some infrared wavelengths inhibit rather than enhance mitochondrial activity, why broadband light outperforms monochromatic sources, and why effects persist across vastly different organisms.

The paper is the first to integrate four separate literature streams:

• Mitochondrial electron transfer follows Marcus physics
• Red and near-infrared light alter mitochondrial function
• Water and protein structures affect electron transfer kinetics
• Infrared radiation changes molecular electron transfer rates

“The novelty lies in the mechanistic integration,” Seheult emphasizes, “not in any single component.”

What Comes Next

The hypothesis is testable. Future experiments could measure how different infrared wavelengths alter specific Marcus crossing configurations in isolated mitochondrial complexes, or track real-time changes in reorganization energy using advanced spectroscopy.

If validated, the implications extend far beyond biology. Urban planning, architecture, workplace design, and lighting standards may all need reconsideration.

Seheult introduces a new term: photometabolism—solar-driven, non-photosynthetic modulation of core metabolic processes.

It’s a concept that positions sunlight not as a passive environmental factor, but as an active participant in the biochemistry of life itself.

I believe that this hypothesis if true has major implications for the built environment and how we live and the type of light that we require to live, and I believe it’s one of the major reasons why we need to be treating our patients outside.

Sources

• Jeffery et al. (2025) – Longer wavelengths in sunlight penetrating human tissue
• Ma et al. (2018) – Infrared perturbation of charge separation and recombination
• Sanderson et al. (2018) – Inhibitory modulation of cytochrome c oxidase with near-infrared wavelengths
• Dai et al. (2026) – Infrared stimulation of mitochondrial metabolism in deep-sea yeast
• Hayashi et al. (2010) – Water-mediated electron transfer in iron-sulfur bridges
• Marcus and Sutin (1985) – Electron transfer reactions in chemistry

The Modern Indoor Environment: A Metabolic Desert?

LED bulbs emit virtually no infrared radiation. Low-emissivity (Low-E) glass windows, designed to improve energy efficiency, block infrared wavelengths.

Seheult measured infrared exposure in his own dining room with windows open: 0.8 watts per square meter.

Step outside under a shade tree with grass reflecting sunlight? 41.9 watts per square meter—more than 50 times higher.

We have set up a situation where outdoors we’re getting plenty of infrared light, versus being indoors where we have Low-E glass blocking it and LED bulbs producing none.

This raises profound questions about whether chronic infrared deficiency could contribute to the rising burden of metabolic diseases, especially among populations spending most of their time indoors.

Seasonal Mortality Patterns Point to Sunlight’s Role

Death rates from heart disease, cancer, stroke, Alzheimer’s, diabetes, and respiratory illness all peak one to three weeks after the shortest day of the year and bottom out after the longest day.

This pattern holds across both infectious and non-infectious causes. The seasonal variation in heart disease deaths alone exceeds total influenza deaths during flu season.

Australia shows the same pattern, but shifted six months—deaths peak in July, their winter. Singapore, 80 miles from the equator with year-round sun, shows no seasonal mortality pattern.

Multiple studies have linked mortality rates to latitude, independent of vitamin D levels, suggesting sunlight itself—particularly its infrared component—plays a direct metabolic role.

Hospitals Are Bringing Patients Outside

Armed with mounting evidence, hospitals worldwide are redesigning care spaces to maximize sunlight exposure.

A $1.5 billion hospital in Footscray, Australia, built ICU beds with direct outdoor access. King’s College Hospital in London invested £2 million to transform its rooftop into a critical care garden where up to six ICU patients can receive treatment surrounded by greenery and natural light.

St. George’s Hospital in London followed suit, creating a neurointensive care rooftop unit. Queen Camilla visited the facility in 2026 to recognize the innovation.

Randomized controlled trials using infrared vests delivering roughly 20–30 watts per square meter (comparable to sitting under a tree) showed 30% reductions in ICU length of stay and improved muscle strength in critically ill COVID-19 patients.

Metabolic Scaling Matches Solar Power Scaling

One of the paper’s most intriguing observations: metabolic rate scales with body mass to the 3/4 power across species from flies to elephants.

Solar power intercepted by an organism also scales to the 3/4 power of mass—nearly identical.

This doesn’t prove causation, but it suggests sunlight could be a universal regulator of metabolic activity across the biosphere, with mitochondria in all organisms tuned to respond to the same infrared wavelengths present in Earth’s solar photon field.

What Makes This Hypothesis Different

Earlier theories proposed infrared light works by activating a photoreceptor in cytochrome c oxidase (complex IV) or by reducing water viscosity around ATP synthase motors.

Seheult’s team doesn’t reject these mechanisms—but argues they’re incomplete.

The Marcus framework explains phenomena earlier models couldn’t: why some infrared wavelengths inhibit rather than enhance mitochondrial activity, why broadband light outperforms monochromatic sources, and why effects persist across vastly different organisms.

The paper is the first to integrate four separate literature streams:

• Mitochondrial electron transfer follows Marcus physics
• Red and near-infrared light alter mitochondrial function
• Water and protein structures affect electron transfer kinetics
• Infrared radiation changes molecular electron transfer rates

“The novelty lies in the mechanistic integration,” Seheult emphasizes, “not in any single component.”

What Comes Next

The hypothesis is testable. Future experiments could measure how different infrared wavelengths alter specific Marcus crossing configurations in isolated mitochondrial complexes, or track real-time changes in reorganization energy using advanced spectroscopy.

If validated, the implications extend far beyond biology. Urban planning, architecture, workplace design, and lighting standards may all need reconsideration.

Seheult introduces a new term: photometabolism—solar-driven, non-photosynthetic modulation of core metabolic processes.

It’s a concept that positions sunlight not as a passive environmental factor, but as an active participant in the biochemistry of life itself.

I believe that this hypothesis if true has major implications for the built environment and how we live and the type of light that we require to live, and I believe it’s one of the major reasons why we need to be treating our patients outside.

Sources

• Jeffery et al. (2025) – Longer wavelengths in sunlight penetrating human tissue
• Ma et al. (2018) – Infrared perturbation of charge separation and recombination
• Sanderson et al. (2018) – Inhibitory modulation of cytochrome c oxidase with near-infrared wavelengths
• Dai et al. (2026) – Infrared stimulation of mitochondrial metabolism in deep-sea yeast
• Hayashi et al. (2010) – Water-mediated electron transfer in iron-sulfur bridges
• Marcus and Sutin (1985) – Electron transfer reactions in chemistry

The research here aligns with the hypothesis, though direct mechanistic proof in human mitochondria remains to be demonstrated.

The Modern Indoor Environment: A Metabolic Desert?

LED bulbs emit virtually no infrared radiation. Low-emissivity (Low-E) glass windows, designed to improve energy efficiency, block infrared wavelengths.

Seheult measured infrared exposure in his own dining room with windows open: 0.8 watts per square meter.

Step outside under a shade tree with grass reflecting sunlight? 41.9 watts per square meter—more than 50 times higher.

We have set up a situation where outdoors we’re getting plenty of infrared light, versus being indoors where we have Low-E glass blocking it and LED bulbs producing none.

This raises profound questions about whether chronic infrared deficiency could contribute to the rising burden of metabolic diseases, especially among populations spending most of their time indoors.

Seasonal Mortality Patterns Point to Sunlight’s Role

Death rates from heart disease, cancer, stroke, Alzheimer’s, diabetes, and respiratory illness all peak one to three weeks after the shortest day of the year and bottom out after the longest day.

This pattern holds across both infectious and non-infectious causes. The seasonal variation in heart disease deaths alone exceeds total influenza deaths during flu season.

Australia shows the same pattern, but shifted six months—deaths peak in July, their winter. Singapore, 80 miles from the equator with year-round sun, shows no seasonal mortality pattern.

Multiple studies have linked mortality rates to latitude, independent of vitamin D levels, suggesting sunlight itself—particularly its infrared component—plays a direct metabolic role.

Hospitals Are Bringing Patients Outside

Armed with mounting evidence, hospitals worldwide are redesigning care spaces to maximize sunlight exposure.

A $1.5 billion hospital in Footscray, Australia, built ICU beds with direct outdoor access. King’s College Hospital in London invested £2 million to transform its rooftop into a critical care garden where up to six ICU patients can receive treatment surrounded by greenery and natural light.

St. George’s Hospital in London followed suit, creating a neurointensive care rooftop unit. Queen Camilla visited the facility in 2026 to recognize the innovation.

Randomized controlled trials using infrared vests delivering roughly 20–30 watts per square meter (comparable to sitting under a tree) showed 30% reductions in ICU length of stay and improved muscle strength in critically ill COVID-19 patients.

Metabolic Scaling Matches Solar Power Scaling

One of the paper’s most intriguing observations: metabolic rate scales with body mass to the 3/4 power across species from flies to elephants.

Solar power intercepted by an organism also scales to the 3/4 power of mass—nearly identical.

This doesn’t prove causation, but it suggests sunlight could be a universal regulator of metabolic activity across the biosphere, with mitochondria in all organisms tuned to respond to the same infrared wavelengths present in Earth’s solar photon field.

What Makes This Hypothesis Different

Earlier theories proposed infrared light works by activating a photoreceptor in cytochrome c oxidase (complex IV) or by reducing water viscosity around ATP synthase motors.

Seheult’s team doesn’t reject these mechanisms—but argues they’re incomplete.

The Marcus framework explains phenomena earlier models couldn’t: why some infrared wavelengths inhibit rather than enhance mitochondrial activity, why broadband light outperforms monochromatic sources, and why effects persist across vastly different organisms.

The paper is the first to integrate four separate literature streams:

• Mitochondrial electron transfer follows Marcus physics
• Red and near-infrared light alter mitochondrial function
• Water and protein structures affect electron transfer kinetics
• Infrared radiation changes molecular electron transfer rates

“The novelty lies in the mechanistic integration,” Seheult emphasizes, “not in any single component.”

What Comes Next

The hypothesis is testable. Future experiments could measure how different infrared wavelengths alter specific Marcus crossing configurations in isolated mitochondrial complexes, or track real-time changes in reorganization energy using advanced spectroscopy.

If validated, the implications extend far beyond biology. Urban planning, architecture, workplace design, and lighting standards may all need reconsideration.

Seheult introduces a new term: photometabolism—solar-driven, non-photosynthetic modulation of core metabolic processes.

It’s a concept that positions sunlight not as a passive environmental factor, but as an active participant in the biochemistry of life itself.

I believe that this hypothesis if true has major implications for the built environment and how we live and the type of light that we require to live, and I believe it’s one of the major reasons why we need to be treating our patients outside.

Sources

• Jeffery et al. (2025) – Longer wavelengths in sunlight penetrating human tissue
• Ma et al. (2018) – Infrared perturbation of charge separation and recombination
• Sanderson et al. (2018) – Inhibitory modulation of cytochrome c oxidase with near-infrared wavelengths
• Dai et al. (2026) – Infrared stimulation of mitochondrial metabolism in deep-sea yeast
• Hayashi et al. (2010) – Water-mediated electron transfer in iron-sulfur bridges
• Marcus and Sutin (1985) – Electron transfer reactions in chemistry

The research here aligns with the hypothesis, though direct mechanistic proof in human mitochondria remains to be demonstrated.

The Modern Indoor Environment: A Metabolic Desert?

LED bulbs emit virtually no infrared radiation. Low-emissivity (Low-E) glass windows, designed to improve energy efficiency, block infrared wavelengths.

Seheult measured infrared exposure in his own dining room with windows open: 0.8 watts per square meter.

Step outside under a shade tree with grass reflecting sunlight? 41.9 watts per square meter—more than 50 times higher.

We have set up a situation where outdoors we’re getting plenty of infrared light, versus being indoors where we have Low-E glass blocking it and LED bulbs producing none.

This raises profound questions about whether chronic infrared deficiency could contribute to the rising burden of metabolic diseases, especially among populations spending most of their time indoors.

Seasonal Mortality Patterns Point to Sunlight’s Role

Death rates from heart disease, cancer, stroke, Alzheimer’s, diabetes, and respiratory illness all peak one to three weeks after the shortest day of the year and bottom out after the longest day.

This pattern holds across both infectious and non-infectious causes. The seasonal variation in heart disease deaths alone exceeds total influenza deaths during flu season.

Australia shows the same pattern, but shifted six months—deaths peak in July, their winter. Singapore, 80 miles from the equator with year-round sun, shows no seasonal mortality pattern.

Multiple studies have linked mortality rates to latitude, independent of vitamin D levels, suggesting sunlight itself—particularly its infrared component—plays a direct metabolic role.

Hospitals Are Bringing Patients Outside

Armed with mounting evidence, hospitals worldwide are redesigning care spaces to maximize sunlight exposure.

A $1.5 billion hospital in Footscray, Australia, built ICU beds with direct outdoor access. King’s College Hospital in London invested £2 million to transform its rooftop into a critical care garden where up to six ICU patients can receive treatment surrounded by greenery and natural light.

St. George’s Hospital in London followed suit, creating a neurointensive care rooftop unit. Queen Camilla visited the facility in 2026 to recognize the innovation.

Randomized controlled trials using infrared vests delivering roughly 20–30 watts per square meter (comparable to sitting under a tree) showed 30% reductions in ICU length of stay and improved muscle strength in critically ill COVID-19 patients.

Metabolic Scaling Matches Solar Power Scaling

One of the paper’s most intriguing observations: metabolic rate scales with body mass to the 3/4 power across species from flies to elephants.

Solar power intercepted by an organism also scales to the 3/4 power of mass—nearly identical.

This doesn’t prove causation, but it suggests sunlight could be a universal regulator of metabolic activity across the biosphere, with mitochondria in all organisms tuned to respond to the same infrared wavelengths present in Earth’s solar photon field.

What Makes This Hypothesis Different

Earlier theories proposed infrared light works by activating a photoreceptor in cytochrome c oxidase (complex IV) or by reducing water viscosity around ATP synthase motors.

Seheult’s team doesn’t reject these mechanisms—but argues they’re incomplete.

The Marcus framework explains phenomena earlier models couldn’t: why some infrared wavelengths inhibit rather than enhance mitochondrial activity, why broadband light outperforms monochromatic sources, and why effects persist across vastly different organisms.

The paper is the first to integrate four separate literature streams:

• Mitochondrial electron transfer follows Marcus physics
• Red and near-infrared light alter mitochondrial function
• Water and protein structures affect electron transfer kinetics
• Infrared radiation changes molecular electron transfer rates

“The novelty lies in the mechanistic integration,” Seheult emphasizes, “not in any single component.”

What Comes Next

The hypothesis is testable. Future experiments could measure how different infrared wavelengths alter specific Marcus crossing configurations in isolated mitochondrial complexes, or track real-time changes in reorganization energy using advanced spectroscopy.

If validated, the implications extend far beyond biology. Urban planning, architecture, workplace design, and lighting standards may all need reconsideration.

Seheult introduces a new term: photometabolism—solar-driven, non-photosynthetic modulation of core metabolic processes.

It’s a concept that positions sunlight not as a passive environmental factor, but as an active participant in the biochemistry of life itself.

I believe that this hypothesis if true has major implications for the built environment and how we live and the type of light that we require to live, and I believe it’s one of the major reasons why we need to be treating our patients outside.

Sources

• Jeffery et al. (2025) – Longer wavelengths in sunlight penetrating human tissue
• Ma et al. (2018) – Infrared perturbation of charge separation and recombination
• Sanderson et al. (2018) – Inhibitory modulation of cytochrome c oxidase with near-infrared wavelengths
• Dai et al. (2026) – Infrared stimulation of mitochondrial metabolism in deep-sea yeast
• Hayashi et al. (2010) – Water-mediated electron transfer in iron-sulfur bridges
• Marcus and Sutin (1985) – Electron transfer reactions in chemistry

• Monochromatic 850 nm: 9% improvement (head and body), 5% (body only)
• 60W incandescent bulb: 28% improvement, sustained for weeks

The research here aligns with the hypothesis, though direct mechanistic proof in human mitochondria remains to be demonstrated.

The Modern Indoor Environment: A Metabolic Desert?

LED bulbs emit virtually no infrared radiation. Low-emissivity (Low-E) glass windows, designed to improve energy efficiency, block infrared wavelengths.

Seheult measured infrared exposure in his own dining room with windows open: 0.8 watts per square meter.

Step outside under a shade tree with grass reflecting sunlight? 41.9 watts per square meter—more than 50 times higher.

We have set up a situation where outdoors we’re getting plenty of infrared light, versus being indoors where we have Low-E glass blocking it and LED bulbs producing none.

This raises profound questions about whether chronic infrared deficiency could contribute to the rising burden of metabolic diseases, especially among populations spending most of their time indoors.

Seasonal Mortality Patterns Point to Sunlight’s Role

Death rates from heart disease, cancer, stroke, Alzheimer’s, diabetes, and respiratory illness all peak one to three weeks after the shortest day of the year and bottom out after the longest day.

This pattern holds across both infectious and non-infectious causes. The seasonal variation in heart disease deaths alone exceeds total influenza deaths during flu season.

Australia shows the same pattern, but shifted six months—deaths peak in July, their winter. Singapore, 80 miles from the equator with year-round sun, shows no seasonal mortality pattern.

Multiple studies have linked mortality rates to latitude, independent of vitamin D levels, suggesting sunlight itself—particularly its infrared component—plays a direct metabolic role.

Hospitals Are Bringing Patients Outside

Armed with mounting evidence, hospitals worldwide are redesigning care spaces to maximize sunlight exposure.

A $1.5 billion hospital in Footscray, Australia, built ICU beds with direct outdoor access. King’s College Hospital in London invested £2 million to transform its rooftop into a critical care garden where up to six ICU patients can receive treatment surrounded by greenery and natural light.

St. George’s Hospital in London followed suit, creating a neurointensive care rooftop unit. Queen Camilla visited the facility in 2026 to recognize the innovation.

Randomized controlled trials using infrared vests delivering roughly 20–30 watts per square meter (comparable to sitting under a tree) showed 30% reductions in ICU length of stay and improved muscle strength in critically ill COVID-19 patients.

Metabolic Scaling Matches Solar Power Scaling

One of the paper’s most intriguing observations: metabolic rate scales with body mass to the 3/4 power across species from flies to elephants.

Solar power intercepted by an organism also scales to the 3/4 power of mass—nearly identical.

This doesn’t prove causation, but it suggests sunlight could be a universal regulator of metabolic activity across the biosphere, with mitochondria in all organisms tuned to respond to the same infrared wavelengths present in Earth’s solar photon field.

What Makes This Hypothesis Different

Earlier theories proposed infrared light works by activating a photoreceptor in cytochrome c oxidase (complex IV) or by reducing water viscosity around ATP synthase motors.

Seheult’s team doesn’t reject these mechanisms—but argues they’re incomplete.

The Marcus framework explains phenomena earlier models couldn’t: why some infrared wavelengths inhibit rather than enhance mitochondrial activity, why broadband light outperforms monochromatic sources, and why effects persist across vastly different organisms.

The paper is the first to integrate four separate literature streams:

• Mitochondrial electron transfer follows Marcus physics
• Red and near-infrared light alter mitochondrial function
• Water and protein structures affect electron transfer kinetics
• Infrared radiation changes molecular electron transfer rates

“The novelty lies in the mechanistic integration,” Seheult emphasizes, “not in any single component.”

What Comes Next

The hypothesis is testable. Future experiments could measure how different infrared wavelengths alter specific Marcus crossing configurations in isolated mitochondrial complexes, or track real-time changes in reorganization energy using advanced spectroscopy.

If validated, the implications extend far beyond biology. Urban planning, architecture, workplace design, and lighting standards may all need reconsideration.

Seheult introduces a new term: photometabolism—solar-driven, non-photosynthetic modulation of core metabolic processes.

It’s a concept that positions sunlight not as a passive environmental factor, but as an active participant in the biochemistry of life itself.

I believe that this hypothesis if true has major implications for the built environment and how we live and the type of light that we require to live, and I believe it’s one of the major reasons why we need to be treating our patients outside.

Sources

• Jeffery et al. (2025) – Longer wavelengths in sunlight penetrating human tissue
• Ma et al. (2018) – Infrared perturbation of charge separation and recombination
• Sanderson et al. (2018) – Inhibitory modulation of cytochrome c oxidase with near-infrared wavelengths
• Dai et al. (2026) – Infrared stimulation of mitochondrial metabolism in deep-sea yeast
• Hayashi et al. (2010) – Water-mediated electron transfer in iron-sulfur bridges
• Marcus and Sutin (1985) – Electron transfer reactions in chemistry

• Monochromatic 850 nm: 9% improvement (head and body), 5% (body only)
• 60W incandescent bulb: 28% improvement, sustained for weeks

The research here aligns with the hypothesis, though direct mechanistic proof in human mitochondria remains to be demonstrated.

The Modern Indoor Environment: A Metabolic Desert?

LED bulbs emit virtually no infrared radiation. Low-emissivity (Low-E) glass windows, designed to improve energy efficiency, block infrared wavelengths.

Seheult measured infrared exposure in his own dining room with windows open: 0.8 watts per square meter.

Step outside under a shade tree with grass reflecting sunlight? 41.9 watts per square meter—more than 50 times higher.

We have set up a situation where outdoors we’re getting plenty of infrared light, versus being indoors where we have Low-E glass blocking it and LED bulbs producing none.

This raises profound questions about whether chronic infrared deficiency could contribute to the rising burden of metabolic diseases, especially among populations spending most of their time indoors.

Seasonal Mortality Patterns Point to Sunlight’s Role

Death rates from heart disease, cancer, stroke, Alzheimer’s, diabetes, and respiratory illness all peak one to three weeks after the shortest day of the year and bottom out after the longest day.

This pattern holds across both infectious and non-infectious causes. The seasonal variation in heart disease deaths alone exceeds total influenza deaths during flu season.

Australia shows the same pattern, but shifted six months—deaths peak in July, their winter. Singapore, 80 miles from the equator with year-round sun, shows no seasonal mortality pattern.

Multiple studies have linked mortality rates to latitude, independent of vitamin D levels, suggesting sunlight itself—particularly its infrared component—plays a direct metabolic role.

Hospitals Are Bringing Patients Outside

Armed with mounting evidence, hospitals worldwide are redesigning care spaces to maximize sunlight exposure.

A $1.5 billion hospital in Footscray, Australia, built ICU beds with direct outdoor access. King’s College Hospital in London invested £2 million to transform its rooftop into a critical care garden where up to six ICU patients can receive treatment surrounded by greenery and natural light.

St. George’s Hospital in London followed suit, creating a neurointensive care rooftop unit. Queen Camilla visited the facility in 2026 to recognize the innovation.

Randomized controlled trials using infrared vests delivering roughly 20–30 watts per square meter (comparable to sitting under a tree) showed 30% reductions in ICU length of stay and improved muscle strength in critically ill COVID-19 patients.

Metabolic Scaling Matches Solar Power Scaling

One of the paper’s most intriguing observations: metabolic rate scales with body mass to the 3/4 power across species from flies to elephants.

Solar power intercepted by an organism also scales to the 3/4 power of mass—nearly identical.

This doesn’t prove causation, but it suggests sunlight could be a universal regulator of metabolic activity across the biosphere, with mitochondria in all organisms tuned to respond to the same infrared wavelengths present in Earth’s solar photon field.

What Makes This Hypothesis Different

Earlier theories proposed infrared light works by activating a photoreceptor in cytochrome c oxidase (complex IV) or by reducing water viscosity around ATP synthase motors.

Seheult’s team doesn’t reject these mechanisms—but argues they’re incomplete.

The Marcus framework explains phenomena earlier models couldn’t: why some infrared wavelengths inhibit rather than enhance mitochondrial activity, why broadband light outperforms monochromatic sources, and why effects persist across vastly different organisms.

The paper is the first to integrate four separate literature streams:

• Mitochondrial electron transfer follows Marcus physics
• Red and near-infrared light alter mitochondrial function
• Water and protein structures affect electron transfer kinetics
• Infrared radiation changes molecular electron transfer rates

“The novelty lies in the mechanistic integration,” Seheult emphasizes, “not in any single component.”

What Comes Next

The hypothesis is testable. Future experiments could measure how different infrared wavelengths alter specific Marcus crossing configurations in isolated mitochondrial complexes, or track real-time changes in reorganization energy using advanced spectroscopy.

If validated, the implications extend far beyond biology. Urban planning, architecture, workplace design, and lighting standards may all need reconsideration.

Seheult introduces a new term: photometabolism—solar-driven, non-photosynthetic modulation of core metabolic processes.

It’s a concept that positions sunlight not as a passive environmental factor, but as an active participant in the biochemistry of life itself.

I believe that this hypothesis if true has major implications for the built environment and how we live and the type of light that we require to live, and I believe it’s one of the major reasons why we need to be treating our patients outside.

Sources

• Jeffery et al. (2025) – Longer wavelengths in sunlight penetrating human tissue
• Ma et al. (2018) – Infrared perturbation of charge separation and recombination
• Sanderson et al. (2018) – Inhibitory modulation of cytochrome c oxidase with near-infrared wavelengths
• Dai et al. (2026) – Infrared stimulation of mitochondrial metabolism in deep-sea yeast
• Hayashi et al. (2010) – Water-mediated electron transfer in iron-sulfur bridges
• Marcus and Sutin (1985) – Electron transfer reactions in chemistry

Research from Jeffery’s lab supports this. When comparing monochromatic 850-nanometer light to a 60-watt incandescent bulb (which emits broad-spectrum infrared), the incandescent bulb produced greater improvements in color blindness.

• Monochromatic 850 nm: 9% improvement (head and body), 5% (body only)
• 60W incandescent bulb: 28% improvement, sustained for weeks

The research here aligns with the hypothesis, though direct mechanistic proof in human mitochondria remains to be demonstrated.

The Modern Indoor Environment: A Metabolic Desert?

LED bulbs emit virtually no infrared radiation. Low-emissivity (Low-E) glass windows, designed to improve energy efficiency, block infrared wavelengths.

Seheult measured infrared exposure in his own dining room with windows open: 0.8 watts per square meter.

Step outside under a shade tree with grass reflecting sunlight? 41.9 watts per square meter—more than 50 times higher.

We have set up a situation where outdoors we’re getting plenty of infrared light, versus being indoors where we have Low-E glass blocking it and LED bulbs producing none.

This raises profound questions about whether chronic infrared deficiency could contribute to the rising burden of metabolic diseases, especially among populations spending most of their time indoors.

Seasonal Mortality Patterns Point to Sunlight’s Role

Death rates from heart disease, cancer, stroke, Alzheimer’s, diabetes, and respiratory illness all peak one to three weeks after the shortest day of the year and bottom out after the longest day.

This pattern holds across both infectious and non-infectious causes. The seasonal variation in heart disease deaths alone exceeds total influenza deaths during flu season.

Australia shows the same pattern, but shifted six months—deaths peak in July, their winter. Singapore, 80 miles from the equator with year-round sun, shows no seasonal mortality pattern.

Multiple studies have linked mortality rates to latitude, independent of vitamin D levels, suggesting sunlight itself—particularly its infrared component—plays a direct metabolic role.

Hospitals Are Bringing Patients Outside

Armed with mounting evidence, hospitals worldwide are redesigning care spaces to maximize sunlight exposure.

A $1.5 billion hospital in Footscray, Australia, built ICU beds with direct outdoor access. King’s College Hospital in London invested £2 million to transform its rooftop into a critical care garden where up to six ICU patients can receive treatment surrounded by greenery and natural light.

St. George’s Hospital in London followed suit, creating a neurointensive care rooftop unit. Queen Camilla visited the facility in 2026 to recognize the innovation.

Randomized controlled trials using infrared vests delivering roughly 20–30 watts per square meter (comparable to sitting under a tree) showed 30% reductions in ICU length of stay and improved muscle strength in critically ill COVID-19 patients.

Metabolic Scaling Matches Solar Power Scaling

One of the paper’s most intriguing observations: metabolic rate scales with body mass to the 3/4 power across species from flies to elephants.

Solar power intercepted by an organism also scales to the 3/4 power of mass—nearly identical.

This doesn’t prove causation, but it suggests sunlight could be a universal regulator of metabolic activity across the biosphere, with mitochondria in all organisms tuned to respond to the same infrared wavelengths present in Earth’s solar photon field.

What Makes This Hypothesis Different

Earlier theories proposed infrared light works by activating a photoreceptor in cytochrome c oxidase (complex IV) or by reducing water viscosity around ATP synthase motors.

Seheult’s team doesn’t reject these mechanisms—but argues they’re incomplete.

The Marcus framework explains phenomena earlier models couldn’t: why some infrared wavelengths inhibit rather than enhance mitochondrial activity, why broadband light outperforms monochromatic sources, and why effects persist across vastly different organisms.

The paper is the first to integrate four separate literature streams:

• Mitochondrial electron transfer follows Marcus physics
• Red and near-infrared light alter mitochondrial function
• Water and protein structures affect electron transfer kinetics
• Infrared radiation changes molecular electron transfer rates

“The novelty lies in the mechanistic integration,” Seheult emphasizes, “not in any single component.”

What Comes Next

The hypothesis is testable. Future experiments could measure how different infrared wavelengths alter specific Marcus crossing configurations in isolated mitochondrial complexes, or track real-time changes in reorganization energy using advanced spectroscopy.

If validated, the implications extend far beyond biology. Urban planning, architecture, workplace design, and lighting standards may all need reconsideration.

Seheult introduces a new term: photometabolism—solar-driven, non-photosynthetic modulation of core metabolic processes.

It’s a concept that positions sunlight not as a passive environmental factor, but as an active participant in the biochemistry of life itself.

I believe that this hypothesis if true has major implications for the built environment and how we live and the type of light that we require to live, and I believe it’s one of the major reasons why we need to be treating our patients outside.

Sources

• Jeffery et al. (2025) – Longer wavelengths in sunlight penetrating human tissue
• Ma et al. (2018) – Infrared perturbation of charge separation and recombination
• Sanderson et al. (2018) – Inhibitory modulation of cytochrome c oxidase with near-infrared wavelengths
• Dai et al. (2026) – Infrared stimulation of mitochondrial metabolism in deep-sea yeast
• Hayashi et al. (2010) – Water-mediated electron transfer in iron-sulfur bridges
• Marcus and Sutin (1985) – Electron transfer reactions in chemistry

Research from Jeffery’s lab supports this. When comparing monochromatic 850-nanometer light to a 60-watt incandescent bulb (which emits broad-spectrum infrared), the incandescent bulb produced greater improvements in color blindness.

• Monochromatic 850 nm: 9% improvement (head and body), 5% (body only)
• 60W incandescent bulb: 28% improvement, sustained for weeks

The research here aligns with the hypothesis, though direct mechanistic proof in human mitochondria remains to be demonstrated.

The Modern Indoor Environment: A Metabolic Desert?

LED bulbs emit virtually no infrared radiation. Low-emissivity (Low-E) glass windows, designed to improve energy efficiency, block infrared wavelengths.

Seheult measured infrared exposure in his own dining room with windows open: 0.8 watts per square meter.

Step outside under a shade tree with grass reflecting sunlight? 41.9 watts per square meter—more than 50 times higher.

We have set up a situation where outdoors we’re getting plenty of infrared light, versus being indoors where we have Low-E glass blocking it and LED bulbs producing none.

This raises profound questions about whether chronic infrared deficiency could contribute to the rising burden of metabolic diseases, especially among populations spending most of their time indoors.

Seasonal Mortality Patterns Point to Sunlight’s Role

Death rates from heart disease, cancer, stroke, Alzheimer’s, diabetes, and respiratory illness all peak one to three weeks after the shortest day of the year and bottom out after the longest day.

This pattern holds across both infectious and non-infectious causes. The seasonal variation in heart disease deaths alone exceeds total influenza deaths during flu season.

Australia shows the same pattern, but shifted six months—deaths peak in July, their winter. Singapore, 80 miles from the equator with year-round sun, shows no seasonal mortality pattern.

Multiple studies have linked mortality rates to latitude, independent of vitamin D levels, suggesting sunlight itself—particularly its infrared component—plays a direct metabolic role.

Hospitals Are Bringing Patients Outside

Armed with mounting evidence, hospitals worldwide are redesigning care spaces to maximize sunlight exposure.

A $1.5 billion hospital in Footscray, Australia, built ICU beds with direct outdoor access. King’s College Hospital in London invested £2 million to transform its rooftop into a critical care garden where up to six ICU patients can receive treatment surrounded by greenery and natural light.

St. George’s Hospital in London followed suit, creating a neurointensive care rooftop unit. Queen Camilla visited the facility in 2026 to recognize the innovation.

Randomized controlled trials using infrared vests delivering roughly 20–30 watts per square meter (comparable to sitting under a tree) showed 30% reductions in ICU length of stay and improved muscle strength in critically ill COVID-19 patients.

Metabolic Scaling Matches Solar Power Scaling

One of the paper’s most intriguing observations: metabolic rate scales with body mass to the 3/4 power across species from flies to elephants.

Solar power intercepted by an organism also scales to the 3/4 power of mass—nearly identical.

This doesn’t prove causation, but it suggests sunlight could be a universal regulator of metabolic activity across the biosphere, with mitochondria in all organisms tuned to respond to the same infrared wavelengths present in Earth’s solar photon field.

What Makes This Hypothesis Different

Earlier theories proposed infrared light works by activating a photoreceptor in cytochrome c oxidase (complex IV) or by reducing water viscosity around ATP synthase motors.

Seheult’s team doesn’t reject these mechanisms—but argues they’re incomplete.

The Marcus framework explains phenomena earlier models couldn’t: why some infrared wavelengths inhibit rather than enhance mitochondrial activity, why broadband light outperforms monochromatic sources, and why effects persist across vastly different organisms.

The paper is the first to integrate four separate literature streams:

• Mitochondrial electron transfer follows Marcus physics
• Red and near-infrared light alter mitochondrial function
• Water and protein structures affect electron transfer kinetics
• Infrared radiation changes molecular electron transfer rates

“The novelty lies in the mechanistic integration,” Seheult emphasizes, “not in any single component.”

What Comes Next

The hypothesis is testable. Future experiments could measure how different infrared wavelengths alter specific Marcus crossing configurations in isolated mitochondrial complexes, or track real-time changes in reorganization energy using advanced spectroscopy.

If validated, the implications extend far beyond biology. Urban planning, architecture, workplace design, and lighting standards may all need reconsideration.

Seheult introduces a new term: photometabolism—solar-driven, non-photosynthetic modulation of core metabolic processes.

It’s a concept that positions sunlight not as a passive environmental factor, but as an active participant in the biochemistry of life itself.

I believe that this hypothesis if true has major implications for the built environment and how we live and the type of light that we require to live, and I believe it’s one of the major reasons why we need to be treating our patients outside.

Sources

• Jeffery et al. (2025) – Longer wavelengths in sunlight penetrating human tissue
• Ma et al. (2018) – Infrared perturbation of charge separation and recombination
• Sanderson et al. (2018) – Inhibitory modulation of cytochrome c oxidase with near-infrared wavelengths
• Dai et al. (2026) – Infrared stimulation of mitochondrial metabolism in deep-sea yeast
• Hayashi et al. (2010) – Water-mediated electron transfer in iron-sulfur bridges
• Marcus and Sutin (1985) – Electron transfer reactions in chemistry

“Sunlight contains a broad spectrum of wavelengths that can interact with many different vibrational modes and electron transfer steps,” he explains, “rather than targeting only one narrow pathway.”

Research from Jeffery’s lab supports this. When comparing monochromatic 850-nanometer light to a 60-watt incandescent bulb (which emits broad-spectrum infrared), the incandescent bulb produced greater improvements in color blindness.

• Monochromatic 850 nm: 9% improvement (head and body), 5% (body only)
• 60W incandescent bulb: 28% improvement, sustained for weeks

The research here aligns with the hypothesis, though direct mechanistic proof in human mitochondria remains to be demonstrated.

The Modern Indoor Environment: A Metabolic Desert?

LED bulbs emit virtually no infrared radiation. Low-emissivity (Low-E) glass windows, designed to improve energy efficiency, block infrared wavelengths.

Seheult measured infrared exposure in his own dining room with windows open: 0.8 watts per square meter.

Step outside under a shade tree with grass reflecting sunlight? 41.9 watts per square meter—more than 50 times higher.

We have set up a situation where outdoors we’re getting plenty of infrared light, versus being indoors where we have Low-E glass blocking it and LED bulbs producing none.

This raises profound questions about whether chronic infrared deficiency could contribute to the rising burden of metabolic diseases, especially among populations spending most of their time indoors.

Seasonal Mortality Patterns Point to Sunlight’s Role

Death rates from heart disease, cancer, stroke, Alzheimer’s, diabetes, and respiratory illness all peak one to three weeks after the shortest day of the year and bottom out after the longest day.

This pattern holds across both infectious and non-infectious causes. The seasonal variation in heart disease deaths alone exceeds total influenza deaths during flu season.

Australia shows the same pattern, but shifted six months—deaths peak in July, their winter. Singapore, 80 miles from the equator with year-round sun, shows no seasonal mortality pattern.

Multiple studies have linked mortality rates to latitude, independent of vitamin D levels, suggesting sunlight itself—particularly its infrared component—plays a direct metabolic role.

Hospitals Are Bringing Patients Outside

Armed with mounting evidence, hospitals worldwide are redesigning care spaces to maximize sunlight exposure.

A $1.5 billion hospital in Footscray, Australia, built ICU beds with direct outdoor access. King’s College Hospital in London invested £2 million to transform its rooftop into a critical care garden where up to six ICU patients can receive treatment surrounded by greenery and natural light.

St. George’s Hospital in London followed suit, creating a neurointensive care rooftop unit. Queen Camilla visited the facility in 2026 to recognize the innovation.

Randomized controlled trials using infrared vests delivering roughly 20–30 watts per square meter (comparable to sitting under a tree) showed 30% reductions in ICU length of stay and improved muscle strength in critically ill COVID-19 patients.

Metabolic Scaling Matches Solar Power Scaling

One of the paper’s most intriguing observations: metabolic rate scales with body mass to the 3/4 power across species from flies to elephants.

Solar power intercepted by an organism also scales to the 3/4 power of mass—nearly identical.

This doesn’t prove causation, but it suggests sunlight could be a universal regulator of metabolic activity across the biosphere, with mitochondria in all organisms tuned to respond to the same infrared wavelengths present in Earth’s solar photon field.

What Makes This Hypothesis Different

Earlier theories proposed infrared light works by activating a photoreceptor in cytochrome c oxidase (complex IV) or by reducing water viscosity around ATP synthase motors.

Seheult’s team doesn’t reject these mechanisms—but argues they’re incomplete.

The Marcus framework explains phenomena earlier models couldn’t: why some infrared wavelengths inhibit rather than enhance mitochondrial activity, why broadband light outperforms monochromatic sources, and why effects persist across vastly different organisms.

The paper is the first to integrate four separate literature streams:

• Mitochondrial electron transfer follows Marcus physics
• Red and near-infrared light alter mitochondrial function
• Water and protein structures affect electron transfer kinetics
• Infrared radiation changes molecular electron transfer rates

“The novelty lies in the mechanistic integration,” Seheult emphasizes, “not in any single component.”

What Comes Next

The hypothesis is testable. Future experiments could measure how different infrared wavelengths alter specific Marcus crossing configurations in isolated mitochondrial complexes, or track real-time changes in reorganization energy using advanced spectroscopy.

If validated, the implications extend far beyond biology. Urban planning, architecture, workplace design, and lighting standards may all need reconsideration.

Seheult introduces a new term: photometabolism—solar-driven, non-photosynthetic modulation of core metabolic processes.

It’s a concept that positions sunlight not as a passive environmental factor, but as an active participant in the biochemistry of life itself.

I believe that this hypothesis if true has major implications for the built environment and how we live and the type of light that we require to live, and I believe it’s one of the major reasons why we need to be treating our patients outside.

Sources

• Jeffery et al. (2025) – Longer wavelengths in sunlight penetrating human tissue
• Ma et al. (2018) – Infrared perturbation of charge separation and recombination
• Sanderson et al. (2018) – Inhibitory modulation of cytochrome c oxidase with near-infrared wavelengths
• Dai et al. (2026) – Infrared stimulation of mitochondrial metabolism in deep-sea yeast
• Hayashi et al. (2010) – Water-mediated electron transfer in iron-sulfur bridges
• Marcus and Sutin (1985) – Electron transfer reactions in chemistry

“Sunlight contains a broad spectrum of wavelengths that can interact with many different vibrational modes and electron transfer steps,” he explains, “rather than targeting only one narrow pathway.”

Research from Jeffery’s lab supports this. When comparing monochromatic 850-nanometer light to a 60-watt incandescent bulb (which emits broad-spectrum infrared), the incandescent bulb produced greater improvements in color blindness.

• Monochromatic 850 nm: 9% improvement (head and body), 5% (body only)
• 60W incandescent bulb: 28% improvement, sustained for weeks

The research here aligns with the hypothesis, though direct mechanistic proof in human mitochondria remains to be demonstrated.

The Modern Indoor Environment: A Metabolic Desert?

LED bulbs emit virtually no infrared radiation. Low-emissivity (Low-E) glass windows, designed to improve energy efficiency, block infrared wavelengths.

Seheult measured infrared exposure in his own dining room with windows open: 0.8 watts per square meter.

Step outside under a shade tree with grass reflecting sunlight? 41.9 watts per square meter—more than 50 times higher.

We have set up a situation where outdoors we’re getting plenty of infrared light, versus being indoors where we have Low-E glass blocking it and LED bulbs producing none.

This raises profound questions about whether chronic infrared deficiency could contribute to the rising burden of metabolic diseases, especially among populations spending most of their time indoors.

Seasonal Mortality Patterns Point to Sunlight’s Role

Death rates from heart disease, cancer, stroke, Alzheimer’s, diabetes, and respiratory illness all peak one to three weeks after the shortest day of the year and bottom out after the longest day.

This pattern holds across both infectious and non-infectious causes. The seasonal variation in heart disease deaths alone exceeds total influenza deaths during flu season.

Australia shows the same pattern, but shifted six months—deaths peak in July, their winter. Singapore, 80 miles from the equator with year-round sun, shows no seasonal mortality pattern.

Multiple studies have linked mortality rates to latitude, independent of vitamin D levels, suggesting sunlight itself—particularly its infrared component—plays a direct metabolic role.

Hospitals Are Bringing Patients Outside

Armed with mounting evidence, hospitals worldwide are redesigning care spaces to maximize sunlight exposure.

A $1.5 billion hospital in Footscray, Australia, built ICU beds with direct outdoor access. King’s College Hospital in London invested £2 million to transform its rooftop into a critical care garden where up to six ICU patients can receive treatment surrounded by greenery and natural light.

St. George’s Hospital in London followed suit, creating a neurointensive care rooftop unit. Queen Camilla visited the facility in 2026 to recognize the innovation.

Randomized controlled trials using infrared vests delivering roughly 20–30 watts per square meter (comparable to sitting under a tree) showed 30% reductions in ICU length of stay and improved muscle strength in critically ill COVID-19 patients.

Metabolic Scaling Matches Solar Power Scaling

One of the paper’s most intriguing observations: metabolic rate scales with body mass to the 3/4 power across species from flies to elephants.

Solar power intercepted by an organism also scales to the 3/4 power of mass—nearly identical.

This doesn’t prove causation, but it suggests sunlight could be a universal regulator of metabolic activity across the biosphere, with mitochondria in all organisms tuned to respond to the same infrared wavelengths present in Earth’s solar photon field.

What Makes This Hypothesis Different

Earlier theories proposed infrared light works by activating a photoreceptor in cytochrome c oxidase (complex IV) or by reducing water viscosity around ATP synthase motors.

Seheult’s team doesn’t reject these mechanisms—but argues they’re incomplete.

The Marcus framework explains phenomena earlier models couldn’t: why some infrared wavelengths inhibit rather than enhance mitochondrial activity, why broadband light outperforms monochromatic sources, and why effects persist across vastly different organisms.

The paper is the first to integrate four separate literature streams:

• Mitochondrial electron transfer follows Marcus physics
• Red and near-infrared light alter mitochondrial function
• Water and protein structures affect electron transfer kinetics
• Infrared radiation changes molecular electron transfer rates

“The novelty lies in the mechanistic integration,” Seheult emphasizes, “not in any single component.”

What Comes Next

The hypothesis is testable. Future experiments could measure how different infrared wavelengths alter specific Marcus crossing configurations in isolated mitochondrial complexes, or track real-time changes in reorganization energy using advanced spectroscopy.

If validated, the implications extend far beyond biology. Urban planning, architecture, workplace design, and lighting standards may all need reconsideration.

Seheult introduces a new term: photometabolism—solar-driven, non-photosynthetic modulation of core metabolic processes.

It’s a concept that positions sunlight not as a passive environmental factor, but as an active participant in the biochemistry of life itself.

I believe that this hypothesis if true has major implications for the built environment and how we live and the type of light that we require to live, and I believe it’s one of the major reasons why we need to be treating our patients outside.

Sources

• Jeffery et al. (2025) – Longer wavelengths in sunlight penetrating human tissue
• Ma et al. (2018) – Infrared perturbation of charge separation and recombination
• Sanderson et al. (2018) – Inhibitory modulation of cytochrome c oxidase with near-infrared wavelengths
• Dai et al. (2026) – Infrared stimulation of mitochondrial metabolism in deep-sea yeast
• Hayashi et al. (2010) – Water-mediated electron transfer in iron-sulfur bridges
• Marcus and Sutin (1985) – Electron transfer reactions in chemistry

But Seheult’s hypothesis suggests broadband infrared from the sun may be even more effective.

“Sunlight contains a broad spectrum of wavelengths that can interact with many different vibrational modes and electron transfer steps,” he explains, “rather than targeting only one narrow pathway.”

Research from Jeffery’s lab supports this. When comparing monochromatic 850-nanometer light to a 60-watt incandescent bulb (which emits broad-spectrum infrared), the incandescent bulb produced greater improvements in color blindness.

• Monochromatic 850 nm: 9% improvement (head and body), 5% (body only)
• 60W incandescent bulb: 28% improvement, sustained for weeks

The research here aligns with the hypothesis, though direct mechanistic proof in human mitochondria remains to be demonstrated.

The Modern Indoor Environment: A Metabolic Desert?

LED bulbs emit virtually no infrared radiation. Low-emissivity (Low-E) glass windows, designed to improve energy efficiency, block infrared wavelengths.

Seheult measured infrared exposure in his own dining room with windows open: 0.8 watts per square meter.

Step outside under a shade tree with grass reflecting sunlight? 41.9 watts per square meter—more than 50 times higher.

We have set up a situation where outdoors we’re getting plenty of infrared light, versus being indoors where we have Low-E glass blocking it and LED bulbs producing none.

This raises profound questions about whether chronic infrared deficiency could contribute to the rising burden of metabolic diseases, especially among populations spending most of their time indoors.

Seasonal Mortality Patterns Point to Sunlight’s Role

Death rates from heart disease, cancer, stroke, Alzheimer’s, diabetes, and respiratory illness all peak one to three weeks after the shortest day of the year and bottom out after the longest day.

This pattern holds across both infectious and non-infectious causes. The seasonal variation in heart disease deaths alone exceeds total influenza deaths during flu season.

Australia shows the same pattern, but shifted six months—deaths peak in July, their winter. Singapore, 80 miles from the equator with year-round sun, shows no seasonal mortality pattern.

Multiple studies have linked mortality rates to latitude, independent of vitamin D levels, suggesting sunlight itself—particularly its infrared component—plays a direct metabolic role.

Hospitals Are Bringing Patients Outside

Armed with mounting evidence, hospitals worldwide are redesigning care spaces to maximize sunlight exposure.

A $1.5 billion hospital in Footscray, Australia, built ICU beds with direct outdoor access. King’s College Hospital in London invested £2 million to transform its rooftop into a critical care garden where up to six ICU patients can receive treatment surrounded by greenery and natural light.

St. George’s Hospital in London followed suit, creating a neurointensive care rooftop unit. Queen Camilla visited the facility in 2026 to recognize the innovation.

Randomized controlled trials using infrared vests delivering roughly 20–30 watts per square meter (comparable to sitting under a tree) showed 30% reductions in ICU length of stay and improved muscle strength in critically ill COVID-19 patients.

Metabolic Scaling Matches Solar Power Scaling

One of the paper’s most intriguing observations: metabolic rate scales with body mass to the 3/4 power across species from flies to elephants.

Solar power intercepted by an organism also scales to the 3/4 power of mass—nearly identical.

This doesn’t prove causation, but it suggests sunlight could be a universal regulator of metabolic activity across the biosphere, with mitochondria in all organisms tuned to respond to the same infrared wavelengths present in Earth’s solar photon field.

What Makes This Hypothesis Different

Earlier theories proposed infrared light works by activating a photoreceptor in cytochrome c oxidase (complex IV) or by reducing water viscosity around ATP synthase motors.

Seheult’s team doesn’t reject these mechanisms—but argues they’re incomplete.

The Marcus framework explains phenomena earlier models couldn’t: why some infrared wavelengths inhibit rather than enhance mitochondrial activity, why broadband light outperforms monochromatic sources, and why effects persist across vastly different organisms.

The paper is the first to integrate four separate literature streams:

• Mitochondrial electron transfer follows Marcus physics
• Red and near-infrared light alter mitochondrial function
• Water and protein structures affect electron transfer kinetics
• Infrared radiation changes molecular electron transfer rates

“The novelty lies in the mechanistic integration,” Seheult emphasizes, “not in any single component.”

What Comes Next

The hypothesis is testable. Future experiments could measure how different infrared wavelengths alter specific Marcus crossing configurations in isolated mitochondrial complexes, or track real-time changes in reorganization energy using advanced spectroscopy.

If validated, the implications extend far beyond biology. Urban planning, architecture, workplace design, and lighting standards may all need reconsideration.

Seheult introduces a new term: photometabolism—solar-driven, non-photosynthetic modulation of core metabolic processes.

It’s a concept that positions sunlight not as a passive environmental factor, but as an active participant in the biochemistry of life itself.

I believe that this hypothesis if true has major implications for the built environment and how we live and the type of light that we require to live, and I believe it’s one of the major reasons why we need to be treating our patients outside.

Sources

• Jeffery et al. (2025) – Longer wavelengths in sunlight penetrating human tissue
• Ma et al. (2018) – Infrared perturbation of charge separation and recombination
• Sanderson et al. (2018) – Inhibitory modulation of cytochrome c oxidase with near-infrared wavelengths
• Dai et al. (2026) – Infrared stimulation of mitochondrial metabolism in deep-sea yeast
• Hayashi et al. (2010) – Water-mediated electron transfer in iron-sulfur bridges
• Marcus and Sutin (1985) – Electron transfer reactions in chemistry

But Seheult’s hypothesis suggests broadband infrared from the sun may be even more effective.

“Sunlight contains a broad spectrum of wavelengths that can interact with many different vibrational modes and electron transfer steps,” he explains, “rather than targeting only one narrow pathway.”

Research from Jeffery’s lab supports this. When comparing monochromatic 850-nanometer light to a 60-watt incandescent bulb (which emits broad-spectrum infrared), the incandescent bulb produced greater improvements in color blindness.

• Monochromatic 850 nm: 9% improvement (head and body), 5% (body only)
• 60W incandescent bulb: 28% improvement, sustained for weeks

The research here aligns with the hypothesis, though direct mechanistic proof in human mitochondria remains to be demonstrated.

The Modern Indoor Environment: A Metabolic Desert?

LED bulbs emit virtually no infrared radiation. Low-emissivity (Low-E) glass windows, designed to improve energy efficiency, block infrared wavelengths.

Seheult measured infrared exposure in his own dining room with windows open: 0.8 watts per square meter.

Step outside under a shade tree with grass reflecting sunlight? 41.9 watts per square meter—more than 50 times higher.

We have set up a situation where outdoors we’re getting plenty of infrared light, versus being indoors where we have Low-E glass blocking it and LED bulbs producing none.

This raises profound questions about whether chronic infrared deficiency could contribute to the rising burden of metabolic diseases, especially among populations spending most of their time indoors.

Seasonal Mortality Patterns Point to Sunlight’s Role

Death rates from heart disease, cancer, stroke, Alzheimer’s, diabetes, and respiratory illness all peak one to three weeks after the shortest day of the year and bottom out after the longest day.

This pattern holds across both infectious and non-infectious causes. The seasonal variation in heart disease deaths alone exceeds total influenza deaths during flu season.

Australia shows the same pattern, but shifted six months—deaths peak in July, their winter. Singapore, 80 miles from the equator with year-round sun, shows no seasonal mortality pattern.

Multiple studies have linked mortality rates to latitude, independent of vitamin D levels, suggesting sunlight itself—particularly its infrared component—plays a direct metabolic role.

Hospitals Are Bringing Patients Outside

Armed with mounting evidence, hospitals worldwide are redesigning care spaces to maximize sunlight exposure.

A $1.5 billion hospital in Footscray, Australia, built ICU beds with direct outdoor access. King’s College Hospital in London invested £2 million to transform its rooftop into a critical care garden where up to six ICU patients can receive treatment surrounded by greenery and natural light.

St. George’s Hospital in London followed suit, creating a neurointensive care rooftop unit. Queen Camilla visited the facility in 2026 to recognize the innovation.

Randomized controlled trials using infrared vests delivering roughly 20–30 watts per square meter (comparable to sitting under a tree) showed 30% reductions in ICU length of stay and improved muscle strength in critically ill COVID-19 patients.

Metabolic Scaling Matches Solar Power Scaling

One of the paper’s most intriguing observations: metabolic rate scales with body mass to the 3/4 power across species from flies to elephants.

Solar power intercepted by an organism also scales to the 3/4 power of mass—nearly identical.

This doesn’t prove causation, but it suggests sunlight could be a universal regulator of metabolic activity across the biosphere, with mitochondria in all organisms tuned to respond to the same infrared wavelengths present in Earth’s solar photon field.

What Makes This Hypothesis Different

Earlier theories proposed infrared light works by activating a photoreceptor in cytochrome c oxidase (complex IV) or by reducing water viscosity around ATP synthase motors.

Seheult’s team doesn’t reject these mechanisms—but argues they’re incomplete.

The Marcus framework explains phenomena earlier models couldn’t: why some infrared wavelengths inhibit rather than enhance mitochondrial activity, why broadband light outperforms monochromatic sources, and why effects persist across vastly different organisms.

The paper is the first to integrate four separate literature streams:

• Mitochondrial electron transfer follows Marcus physics
• Red and near-infrared light alter mitochondrial function
• Water and protein structures affect electron transfer kinetics
• Infrared radiation changes molecular electron transfer rates

“The novelty lies in the mechanistic integration,” Seheult emphasizes, “not in any single component.”

What Comes Next

The hypothesis is testable. Future experiments could measure how different infrared wavelengths alter specific Marcus crossing configurations in isolated mitochondrial complexes, or track real-time changes in reorganization energy using advanced spectroscopy.

If validated, the implications extend far beyond biology. Urban planning, architecture, workplace design, and lighting standards may all need reconsideration.

Seheult introduces a new term: photometabolism—solar-driven, non-photosynthetic modulation of core metabolic processes.

It’s a concept that positions sunlight not as a passive environmental factor, but as an active participant in the biochemistry of life itself.

I believe that this hypothesis if true has major implications for the built environment and how we live and the type of light that we require to live, and I believe it’s one of the major reasons why we need to be treating our patients outside.

Sources

• Jeffery et al. (2025) – Longer wavelengths in sunlight penetrating human tissue
• Ma et al. (2018) – Infrared perturbation of charge separation and recombination
• Sanderson et al. (2018) – Inhibitory modulation of cytochrome c oxidase with near-infrared wavelengths
• Dai et al. (2026) – Infrared stimulation of mitochondrial metabolism in deep-sea yeast
• Hayashi et al. (2010) – Water-mediated electron transfer in iron-sulfur bridges
• Marcus and Sutin (1985) – Electron transfer reactions in chemistry

Clinical studies using single-wavelength infrared devices have shown benefits—from reducing ICU length of stay to improving muscle strength in COVID-19 patients.

But Seheult’s hypothesis suggests broadband infrared from the sun may be even more effective.

“Sunlight contains a broad spectrum of wavelengths that can interact with many different vibrational modes and electron transfer steps,” he explains, “rather than targeting only one narrow pathway.”

Research from Jeffery’s lab supports this. When comparing monochromatic 850-nanometer light to a 60-watt incandescent bulb (which emits broad-spectrum infrared), the incandescent bulb produced greater improvements in color blindness.

• Monochromatic 850 nm: 9% improvement (head and body), 5% (body only)
• 60W incandescent bulb: 28% improvement, sustained for weeks

The research here aligns with the hypothesis, though direct mechanistic proof in human mitochondria remains to be demonstrated.

The Modern Indoor Environment: A Metabolic Desert?

LED bulbs emit virtually no infrared radiation. Low-emissivity (Low-E) glass windows, designed to improve energy efficiency, block infrared wavelengths.

Seheult measured infrared exposure in his own dining room with windows open: 0.8 watts per square meter.

Step outside under a shade tree with grass reflecting sunlight? 41.9 watts per square meter—more than 50 times higher.

We have set up a situation where outdoors we’re getting plenty of infrared light, versus being indoors where we have Low-E glass blocking it and LED bulbs producing none.

This raises profound questions about whether chronic infrared deficiency could contribute to the rising burden of metabolic diseases, especially among populations spending most of their time indoors.

Seasonal Mortality Patterns Point to Sunlight’s Role

Death rates from heart disease, cancer, stroke, Alzheimer’s, diabetes, and respiratory illness all peak one to three weeks after the shortest day of the year and bottom out after the longest day.

This pattern holds across both infectious and non-infectious causes. The seasonal variation in heart disease deaths alone exceeds total influenza deaths during flu season.

Australia shows the same pattern, but shifted six months—deaths peak in July, their winter. Singapore, 80 miles from the equator with year-round sun, shows no seasonal mortality pattern.

Multiple studies have linked mortality rates to latitude, independent of vitamin D levels, suggesting sunlight itself—particularly its infrared component—plays a direct metabolic role.

Hospitals Are Bringing Patients Outside

Armed with mounting evidence, hospitals worldwide are redesigning care spaces to maximize sunlight exposure.

A $1.5 billion hospital in Footscray, Australia, built ICU beds with direct outdoor access. King’s College Hospital in London invested £2 million to transform its rooftop into a critical care garden where up to six ICU patients can receive treatment surrounded by greenery and natural light.

St. George’s Hospital in London followed suit, creating a neurointensive care rooftop unit. Queen Camilla visited the facility in 2026 to recognize the innovation.

Randomized controlled trials using infrared vests delivering roughly 20–30 watts per square meter (comparable to sitting under a tree) showed 30% reductions in ICU length of stay and improved muscle strength in critically ill COVID-19 patients.

Metabolic Scaling Matches Solar Power Scaling

One of the paper’s most intriguing observations: metabolic rate scales with body mass to the 3/4 power across species from flies to elephants.

Solar power intercepted by an organism also scales to the 3/4 power of mass—nearly identical.

This doesn’t prove causation, but it suggests sunlight could be a universal regulator of metabolic activity across the biosphere, with mitochondria in all organisms tuned to respond to the same infrared wavelengths present in Earth’s solar photon field.

What Makes This Hypothesis Different

Earlier theories proposed infrared light works by activating a photoreceptor in cytochrome c oxidase (complex IV) or by reducing water viscosity around ATP synthase motors.

Seheult’s team doesn’t reject these mechanisms—but argues they’re incomplete.

The Marcus framework explains phenomena earlier models couldn’t: why some infrared wavelengths inhibit rather than enhance mitochondrial activity, why broadband light outperforms monochromatic sources, and why effects persist across vastly different organisms.

The paper is the first to integrate four separate literature streams:

• Mitochondrial electron transfer follows Marcus physics
• Red and near-infrared light alter mitochondrial function
• Water and protein structures affect electron transfer kinetics
• Infrared radiation changes molecular electron transfer rates

“The novelty lies in the mechanistic integration,” Seheult emphasizes, “not in any single component.”

What Comes Next

The hypothesis is testable. Future experiments could measure how different infrared wavelengths alter specific Marcus crossing configurations in isolated mitochondrial complexes, or track real-time changes in reorganization energy using advanced spectroscopy.

If validated, the implications extend far beyond biology. Urban planning, architecture, workplace design, and lighting standards may all need reconsideration.

Seheult introduces a new term: photometabolism—solar-driven, non-photosynthetic modulation of core metabolic processes.

It’s a concept that positions sunlight not as a passive environmental factor, but as an active participant in the biochemistry of life itself.

I believe that this hypothesis if true has major implications for the built environment and how we live and the type of light that we require to live, and I believe it’s one of the major reasons why we need to be treating our patients outside.

Sources

• Jeffery et al. (2025) – Longer wavelengths in sunlight penetrating human tissue
• Ma et al. (2018) – Infrared perturbation of charge separation and recombination
• Sanderson et al. (2018) – Inhibitory modulation of cytochrome c oxidase with near-infrared wavelengths
• Dai et al. (2026) – Infrared stimulation of mitochondrial metabolism in deep-sea yeast
• Hayashi et al. (2010) – Water-mediated electron transfer in iron-sulfur bridges
• Marcus and Sutin (1985) – Electron transfer reactions in chemistry

Clinical studies using single-wavelength infrared devices have shown benefits—from reducing ICU length of stay to improving muscle strength in COVID-19 patients.

But Seheult’s hypothesis suggests broadband infrared from the sun may be even more effective.

“Sunlight contains a broad spectrum of wavelengths that can interact with many different vibrational modes and electron transfer steps,” he explains, “rather than targeting only one narrow pathway.”

Research from Jeffery’s lab supports this. When comparing monochromatic 850-nanometer light to a 60-watt incandescent bulb (which emits broad-spectrum infrared), the incandescent bulb produced greater improvements in color blindness.

• Monochromatic 850 nm: 9% improvement (head and body), 5% (body only)
• 60W incandescent bulb: 28% improvement, sustained for weeks

The research here aligns with the hypothesis, though direct mechanistic proof in human mitochondria remains to be demonstrated.

The Modern Indoor Environment: A Metabolic Desert?

LED bulbs emit virtually no infrared radiation. Low-emissivity (Low-E) glass windows, designed to improve energy efficiency, block infrared wavelengths.

Seheult measured infrared exposure in his own dining room with windows open: 0.8 watts per square meter.

Step outside under a shade tree with grass reflecting sunlight? 41.9 watts per square meter—more than 50 times higher.

We have set up a situation where outdoors we’re getting plenty of infrared light, versus being indoors where we have Low-E glass blocking it and LED bulbs producing none.

This raises profound questions about whether chronic infrared deficiency could contribute to the rising burden of metabolic diseases, especially among populations spending most of their time indoors.

Seasonal Mortality Patterns Point to Sunlight’s Role

Death rates from heart disease, cancer, stroke, Alzheimer’s, diabetes, and respiratory illness all peak one to three weeks after the shortest day of the year and bottom out after the longest day.

This pattern holds across both infectious and non-infectious causes. The seasonal variation in heart disease deaths alone exceeds total influenza deaths during flu season.

Australia shows the same pattern, but shifted six months—deaths peak in July, their winter. Singapore, 80 miles from the equator with year-round sun, shows no seasonal mortality pattern.

Multiple studies have linked mortality rates to latitude, independent of vitamin D levels, suggesting sunlight itself—particularly its infrared component—plays a direct metabolic role.

Hospitals Are Bringing Patients Outside

Armed with mounting evidence, hospitals worldwide are redesigning care spaces to maximize sunlight exposure.

A $1.5 billion hospital in Footscray, Australia, built ICU beds with direct outdoor access. King’s College Hospital in London invested £2 million to transform its rooftop into a critical care garden where up to six ICU patients can receive treatment surrounded by greenery and natural light.

St. George’s Hospital in London followed suit, creating a neurointensive care rooftop unit. Queen Camilla visited the facility in 2026 to recognize the innovation.

Randomized controlled trials using infrared vests delivering roughly 20–30 watts per square meter (comparable to sitting under a tree) showed 30% reductions in ICU length of stay and improved muscle strength in critically ill COVID-19 patients.

Metabolic Scaling Matches Solar Power Scaling

One of the paper’s most intriguing observations: metabolic rate scales with body mass to the 3/4 power across species from flies to elephants.

Solar power intercepted by an organism also scales to the 3/4 power of mass—nearly identical.

This doesn’t prove causation, but it suggests sunlight could be a universal regulator of metabolic activity across the biosphere, with mitochondria in all organisms tuned to respond to the same infrared wavelengths present in Earth’s solar photon field.

What Makes This Hypothesis Different

Earlier theories proposed infrared light works by activating a photoreceptor in cytochrome c oxidase (complex IV) or by reducing water viscosity around ATP synthase motors.

Seheult’s team doesn’t reject these mechanisms—but argues they’re incomplete.

The Marcus framework explains phenomena earlier models couldn’t: why some infrared wavelengths inhibit rather than enhance mitochondrial activity, why broadband light outperforms monochromatic sources, and why effects persist across vastly different organisms.

The paper is the first to integrate four separate literature streams:

• Mitochondrial electron transfer follows Marcus physics
• Red and near-infrared light alter mitochondrial function
• Water and protein structures affect electron transfer kinetics
• Infrared radiation changes molecular electron transfer rates

“The novelty lies in the mechanistic integration,” Seheult emphasizes, “not in any single component.”

What Comes Next

The hypothesis is testable. Future experiments could measure how different infrared wavelengths alter specific Marcus crossing configurations in isolated mitochondrial complexes, or track real-time changes in reorganization energy using advanced spectroscopy.

If validated, the implications extend far beyond biology. Urban planning, architecture, workplace design, and lighting standards may all need reconsideration.

Seheult introduces a new term: photometabolism—solar-driven, non-photosynthetic modulation of core metabolic processes.

It’s a concept that positions sunlight not as a passive environmental factor, but as an active participant in the biochemistry of life itself.

I believe that this hypothesis if true has major implications for the built environment and how we live and the type of light that we require to live, and I believe it’s one of the major reasons why we need to be treating our patients outside.

Sources

• Jeffery et al. (2025) – Longer wavelengths in sunlight penetrating human tissue
• Ma et al. (2018) – Infrared perturbation of charge separation and recombination
• Sanderson et al. (2018) – Inhibitory modulation of cytochrome c oxidase with near-infrared wavelengths
• Dai et al. (2026) – Infrared stimulation of mitochondrial metabolism in deep-sea yeast
• Hayashi et al. (2010) – Water-mediated electron transfer in iron-sulfur bridges
• Marcus and Sutin (1985) – Electron transfer reactions in chemistry

Why Broadband Sunlight May Beat Monochromatic LEDs

Clinical studies using single-wavelength infrared devices have shown benefits—from reducing ICU length of stay to improving muscle strength in COVID-19 patients.

But Seheult’s hypothesis suggests broadband infrared from the sun may be even more effective.

“Sunlight contains a broad spectrum of wavelengths that can interact with many different vibrational modes and electron transfer steps,” he explains, “rather than targeting only one narrow pathway.”

Research from Jeffery’s lab supports this. When comparing monochromatic 850-nanometer light to a 60-watt incandescent bulb (which emits broad-spectrum infrared), the incandescent bulb produced greater improvements in color blindness.

• Monochromatic 850 nm: 9% improvement (head and body), 5% (body only)
• 60W incandescent bulb: 28% improvement, sustained for weeks

The research here aligns with the hypothesis, though direct mechanistic proof in human mitochondria remains to be demonstrated.

The Modern Indoor Environment: A Metabolic Desert?

LED bulbs emit virtually no infrared radiation. Low-emissivity (Low-E) glass windows, designed to improve energy efficiency, block infrared wavelengths.

Seheult measured infrared exposure in his own dining room with windows open: 0.8 watts per square meter.

Step outside under a shade tree with grass reflecting sunlight? 41.9 watts per square meter—more than 50 times higher.

We have set up a situation where outdoors we’re getting plenty of infrared light, versus being indoors where we have Low-E glass blocking it and LED bulbs producing none.

This raises profound questions about whether chronic infrared deficiency could contribute to the rising burden of metabolic diseases, especially among populations spending most of their time indoors.

Seasonal Mortality Patterns Point to Sunlight’s Role

Death rates from heart disease, cancer, stroke, Alzheimer’s, diabetes, and respiratory illness all peak one to three weeks after the shortest day of the year and bottom out after the longest day.

This pattern holds across both infectious and non-infectious causes. The seasonal variation in heart disease deaths alone exceeds total influenza deaths during flu season.

Australia shows the same pattern, but shifted six months—deaths peak in July, their winter. Singapore, 80 miles from the equator with year-round sun, shows no seasonal mortality pattern.

Multiple studies have linked mortality rates to latitude, independent of vitamin D levels, suggesting sunlight itself—particularly its infrared component—plays a direct metabolic role.

Hospitals Are Bringing Patients Outside

Armed with mounting evidence, hospitals worldwide are redesigning care spaces to maximize sunlight exposure.

A $1.5 billion hospital in Footscray, Australia, built ICU beds with direct outdoor access. King’s College Hospital in London invested £2 million to transform its rooftop into a critical care garden where up to six ICU patients can receive treatment surrounded by greenery and natural light.

St. George’s Hospital in London followed suit, creating a neurointensive care rooftop unit. Queen Camilla visited the facility in 2026 to recognize the innovation.

Randomized controlled trials using infrared vests delivering roughly 20–30 watts per square meter (comparable to sitting under a tree) showed 30% reductions in ICU length of stay and improved muscle strength in critically ill COVID-19 patients.

Metabolic Scaling Matches Solar Power Scaling

One of the paper’s most intriguing observations: metabolic rate scales with body mass to the 3/4 power across species from flies to elephants.

Solar power intercepted by an organism also scales to the 3/4 power of mass—nearly identical.

This doesn’t prove causation, but it suggests sunlight could be a universal regulator of metabolic activity across the biosphere, with mitochondria in all organisms tuned to respond to the same infrared wavelengths present in Earth’s solar photon field.

What Makes This Hypothesis Different

Earlier theories proposed infrared light works by activating a photoreceptor in cytochrome c oxidase (complex IV) or by reducing water viscosity around ATP synthase motors.

Seheult’s team doesn’t reject these mechanisms—but argues they’re incomplete.

The Marcus framework explains phenomena earlier models couldn’t: why some infrared wavelengths inhibit rather than enhance mitochondrial activity, why broadband light outperforms monochromatic sources, and why effects persist across vastly different organisms.

The paper is the first to integrate four separate literature streams:

• Mitochondrial electron transfer follows Marcus physics
• Red and near-infrared light alter mitochondrial function
• Water and protein structures affect electron transfer kinetics
• Infrared radiation changes molecular electron transfer rates

“The novelty lies in the mechanistic integration,” Seheult emphasizes, “not in any single component.”

What Comes Next

The hypothesis is testable. Future experiments could measure how different infrared wavelengths alter specific Marcus crossing configurations in isolated mitochondrial complexes, or track real-time changes in reorganization energy using advanced spectroscopy.

If validated, the implications extend far beyond biology. Urban planning, architecture, workplace design, and lighting standards may all need reconsideration.

Seheult introduces a new term: photometabolism—solar-driven, non-photosynthetic modulation of core metabolic processes.

It’s a concept that positions sunlight not as a passive environmental factor, but as an active participant in the biochemistry of life itself.

I believe that this hypothesis if true has major implications for the built environment and how we live and the type of light that we require to live, and I believe it’s one of the major reasons why we need to be treating our patients outside.

Sources

• Jeffery et al. (2025) – Longer wavelengths in sunlight penetrating human tissue
• Ma et al. (2018) – Infrared perturbation of charge separation and recombination
• Sanderson et al. (2018) – Inhibitory modulation of cytochrome c oxidase with near-infrared wavelengths
• Dai et al. (2026) – Infrared stimulation of mitochondrial metabolism in deep-sea yeast
• Hayashi et al. (2010) – Water-mediated electron transfer in iron-sulfur bridges
• Marcus and Sutin (1985) – Electron transfer reactions in chemistry

Why Broadband Sunlight May Beat Monochromatic LEDs

Clinical studies using single-wavelength infrared devices have shown benefits—from reducing ICU length of stay to improving muscle strength in COVID-19 patients.

But Seheult’s hypothesis suggests broadband infrared from the sun may be even more effective.

“Sunlight contains a broad spectrum of wavelengths that can interact with many different vibrational modes and electron transfer steps,” he explains, “rather than targeting only one narrow pathway.”

Research from Jeffery’s lab supports this. When comparing monochromatic 850-nanometer light to a 60-watt incandescent bulb (which emits broad-spectrum infrared), the incandescent bulb produced greater improvements in color blindness.

• Monochromatic 850 nm: 9% improvement (head and body), 5% (body only)
• 60W incandescent bulb: 28% improvement, sustained for weeks

The research here aligns with the hypothesis, though direct mechanistic proof in human mitochondria remains to be demonstrated.

The Modern Indoor Environment: A Metabolic Desert?

LED bulbs emit virtually no infrared radiation. Low-emissivity (Low-E) glass windows, designed to improve energy efficiency, block infrared wavelengths.

Seheult measured infrared exposure in his own dining room with windows open: 0.8 watts per square meter.

Step outside under a shade tree with grass reflecting sunlight? 41.9 watts per square meter—more than 50 times higher.

We have set up a situation where outdoors we’re getting plenty of infrared light, versus being indoors where we have Low-E glass blocking it and LED bulbs producing none.

This raises profound questions about whether chronic infrared deficiency could contribute to the rising burden of metabolic diseases, especially among populations spending most of their time indoors.

Seasonal Mortality Patterns Point to Sunlight’s Role

Death rates from heart disease, cancer, stroke, Alzheimer’s, diabetes, and respiratory illness all peak one to three weeks after the shortest day of the year and bottom out after the longest day.

This pattern holds across both infectious and non-infectious causes. The seasonal variation in heart disease deaths alone exceeds total influenza deaths during flu season.

Australia shows the same pattern, but shifted six months—deaths peak in July, their winter. Singapore, 80 miles from the equator with year-round sun, shows no seasonal mortality pattern.

Multiple studies have linked mortality rates to latitude, independent of vitamin D levels, suggesting sunlight itself—particularly its infrared component—plays a direct metabolic role.

Hospitals Are Bringing Patients Outside

Armed with mounting evidence, hospitals worldwide are redesigning care spaces to maximize sunlight exposure.

A $1.5 billion hospital in Footscray, Australia, built ICU beds with direct outdoor access. King’s College Hospital in London invested £2 million to transform its rooftop into a critical care garden where up to six ICU patients can receive treatment surrounded by greenery and natural light.

St. George’s Hospital in London followed suit, creating a neurointensive care rooftop unit. Queen Camilla visited the facility in 2026 to recognize the innovation.

Randomized controlled trials using infrared vests delivering roughly 20–30 watts per square meter (comparable to sitting under a tree) showed 30% reductions in ICU length of stay and improved muscle strength in critically ill COVID-19 patients.

Metabolic Scaling Matches Solar Power Scaling

One of the paper’s most intriguing observations: metabolic rate scales with body mass to the 3/4 power across species from flies to elephants.

Solar power intercepted by an organism also scales to the 3/4 power of mass—nearly identical.

This doesn’t prove causation, but it suggests sunlight could be a universal regulator of metabolic activity across the biosphere, with mitochondria in all organisms tuned to respond to the same infrared wavelengths present in Earth’s solar photon field.

What Makes This Hypothesis Different

Earlier theories proposed infrared light works by activating a photoreceptor in cytochrome c oxidase (complex IV) or by reducing water viscosity around ATP synthase motors.

Seheult’s team doesn’t reject these mechanisms—but argues they’re incomplete.

The Marcus framework explains phenomena earlier models couldn’t: why some infrared wavelengths inhibit rather than enhance mitochondrial activity, why broadband light outperforms monochromatic sources, and why effects persist across vastly different organisms.

The paper is the first to integrate four separate literature streams:

• Mitochondrial electron transfer follows Marcus physics
• Red and near-infrared light alter mitochondrial function
• Water and protein structures affect electron transfer kinetics
• Infrared radiation changes molecular electron transfer rates

“The novelty lies in the mechanistic integration,” Seheult emphasizes, “not in any single component.”

What Comes Next

The hypothesis is testable. Future experiments could measure how different infrared wavelengths alter specific Marcus crossing configurations in isolated mitochondrial complexes, or track real-time changes in reorganization energy using advanced spectroscopy.

If validated, the implications extend far beyond biology. Urban planning, architecture, workplace design, and lighting standards may all need reconsideration.

Seheult introduces a new term: photometabolism—solar-driven, non-photosynthetic modulation of core metabolic processes.

It’s a concept that positions sunlight not as a passive environmental factor, but as an active participant in the biochemistry of life itself.

I believe that this hypothesis if true has major implications for the built environment and how we live and the type of light that we require to live, and I believe it’s one of the major reasons why we need to be treating our patients outside.

Sources

• Jeffery et al. (2025) – Longer wavelengths in sunlight penetrating human tissue
• Ma et al. (2018) – Infrared perturbation of charge separation and recombination
• Sanderson et al. (2018) – Inhibitory modulation of cytochrome c oxidase with near-infrared wavelengths
• Dai et al. (2026) – Infrared stimulation of mitochondrial metabolism in deep-sea yeast
• Hayashi et al. (2010) – Water-mediated electron transfer in iron-sulfur bridges
• Marcus and Sutin (1985) – Electron transfer reactions in chemistry

Proteomics revealed the most upregulated protein after infrared exposure was a mitochondrial ribosomal protein (MRPs8), increased 6.7-fold.

Why Broadband Sunlight May Beat Monochromatic LEDs

Clinical studies using single-wavelength infrared devices have shown benefits—from reducing ICU length of stay to improving muscle strength in COVID-19 patients.

But Seheult’s hypothesis suggests broadband infrared from the sun may be even more effective.

“Sunlight contains a broad spectrum of wavelengths that can interact with many different vibrational modes and electron transfer steps,” he explains, “rather than targeting only one narrow pathway.”

Research from Jeffery’s lab supports this. When comparing monochromatic 850-nanometer light to a 60-watt incandescent bulb (which emits broad-spectrum infrared), the incandescent bulb produced greater improvements in color blindness.

• Monochromatic 850 nm: 9% improvement (head and body), 5% (body only)
• 60W incandescent bulb: 28% improvement, sustained for weeks

The research here aligns with the hypothesis, though direct mechanistic proof in human mitochondria remains to be demonstrated.

The Modern Indoor Environment: A Metabolic Desert?

LED bulbs emit virtually no infrared radiation. Low-emissivity (Low-E) glass windows, designed to improve energy efficiency, block infrared wavelengths.

Seheult measured infrared exposure in his own dining room with windows open: 0.8 watts per square meter.

Step outside under a shade tree with grass reflecting sunlight? 41.9 watts per square meter—more than 50 times higher.

We have set up a situation where outdoors we’re getting plenty of infrared light, versus being indoors where we have Low-E glass blocking it and LED bulbs producing none.

This raises profound questions about whether chronic infrared deficiency could contribute to the rising burden of metabolic diseases, especially among populations spending most of their time indoors.

Seasonal Mortality Patterns Point to Sunlight’s Role

Death rates from heart disease, cancer, stroke, Alzheimer’s, diabetes, and respiratory illness all peak one to three weeks after the shortest day of the year and bottom out after the longest day.

This pattern holds across both infectious and non-infectious causes. The seasonal variation in heart disease deaths alone exceeds total influenza deaths during flu season.

Australia shows the same pattern, but shifted six months—deaths peak in July, their winter. Singapore, 80 miles from the equator with year-round sun, shows no seasonal mortality pattern.

Multiple studies have linked mortality rates to latitude, independent of vitamin D levels, suggesting sunlight itself—particularly its infrared component—plays a direct metabolic role.

Hospitals Are Bringing Patients Outside

Armed with mounting evidence, hospitals worldwide are redesigning care spaces to maximize sunlight exposure.

A $1.5 billion hospital in Footscray, Australia, built ICU beds with direct outdoor access. King’s College Hospital in London invested £2 million to transform its rooftop into a critical care garden where up to six ICU patients can receive treatment surrounded by greenery and natural light.

St. George’s Hospital in London followed suit, creating a neurointensive care rooftop unit. Queen Camilla visited the facility in 2026 to recognize the innovation.

Randomized controlled trials using infrared vests delivering roughly 20–30 watts per square meter (comparable to sitting under a tree) showed 30% reductions in ICU length of stay and improved muscle strength in critically ill COVID-19 patients.

Metabolic Scaling Matches Solar Power Scaling

One of the paper’s most intriguing observations: metabolic rate scales with body mass to the 3/4 power across species from flies to elephants.

Solar power intercepted by an organism also scales to the 3/4 power of mass—nearly identical.

This doesn’t prove causation, but it suggests sunlight could be a universal regulator of metabolic activity across the biosphere, with mitochondria in all organisms tuned to respond to the same infrared wavelengths present in Earth’s solar photon field.

What Makes This Hypothesis Different

Earlier theories proposed infrared light works by activating a photoreceptor in cytochrome c oxidase (complex IV) or by reducing water viscosity around ATP synthase motors.

Seheult’s team doesn’t reject these mechanisms—but argues they’re incomplete.

The Marcus framework explains phenomena earlier models couldn’t: why some infrared wavelengths inhibit rather than enhance mitochondrial activity, why broadband light outperforms monochromatic sources, and why effects persist across vastly different organisms.

The paper is the first to integrate four separate literature streams:

• Mitochondrial electron transfer follows Marcus physics
• Red and near-infrared light alter mitochondrial function
• Water and protein structures affect electron transfer kinetics
• Infrared radiation changes molecular electron transfer rates

“The novelty lies in the mechanistic integration,” Seheult emphasizes, “not in any single component.”

What Comes Next

The hypothesis is testable. Future experiments could measure how different infrared wavelengths alter specific Marcus crossing configurations in isolated mitochondrial complexes, or track real-time changes in reorganization energy using advanced spectroscopy.

If validated, the implications extend far beyond biology. Urban planning, architecture, workplace design, and lighting standards may all need reconsideration.

Seheult introduces a new term: photometabolism—solar-driven, non-photosynthetic modulation of core metabolic processes.

It’s a concept that positions sunlight not as a passive environmental factor, but as an active participant in the biochemistry of life itself.

I believe that this hypothesis if true has major implications for the built environment and how we live and the type of light that we require to live, and I believe it’s one of the major reasons why we need to be treating our patients outside.

Sources

• Jeffery et al. (2025) – Longer wavelengths in sunlight penetrating human tissue
• Ma et al. (2018) – Infrared perturbation of charge separation and recombination
• Sanderson et al. (2018) – Inhibitory modulation of cytochrome c oxidase with near-infrared wavelengths
• Dai et al. (2026) – Infrared stimulation of mitochondrial metabolism in deep-sea yeast
• Hayashi et al. (2010) – Water-mediated electron transfer in iron-sulfur bridges
• Marcus and Sutin (1985) – Electron transfer reactions in chemistry

Proteomics revealed the most upregulated protein after infrared exposure was a mitochondrial ribosomal protein (MRPs8), increased 6.7-fold.

Why Broadband Sunlight May Beat Monochromatic LEDs

Clinical studies using single-wavelength infrared devices have shown benefits—from reducing ICU length of stay to improving muscle strength in COVID-19 patients.

But Seheult’s hypothesis suggests broadband infrared from the sun may be even more effective.

“Sunlight contains a broad spectrum of wavelengths that can interact with many different vibrational modes and electron transfer steps,” he explains, “rather than targeting only one narrow pathway.”

Research from Jeffery’s lab supports this. When comparing monochromatic 850-nanometer light to a 60-watt incandescent bulb (which emits broad-spectrum infrared), the incandescent bulb produced greater improvements in color blindness.

• Monochromatic 850 nm: 9% improvement (head and body), 5% (body only)
• 60W incandescent bulb: 28% improvement, sustained for weeks

The research here aligns with the hypothesis, though direct mechanistic proof in human mitochondria remains to be demonstrated.

The Modern Indoor Environment: A Metabolic Desert?

LED bulbs emit virtually no infrared radiation. Low-emissivity (Low-E) glass windows, designed to improve energy efficiency, block infrared wavelengths.

Seheult measured infrared exposure in his own dining room with windows open: 0.8 watts per square meter.

Step outside under a shade tree with grass reflecting sunlight? 41.9 watts per square meter—more than 50 times higher.

We have set up a situation where outdoors we’re getting plenty of infrared light, versus being indoors where we have Low-E glass blocking it and LED bulbs producing none.

This raises profound questions about whether chronic infrared deficiency could contribute to the rising burden of metabolic diseases, especially among populations spending most of their time indoors.

Seasonal Mortality Patterns Point to Sunlight’s Role

Death rates from heart disease, cancer, stroke, Alzheimer’s, diabetes, and respiratory illness all peak one to three weeks after the shortest day of the year and bottom out after the longest day.

This pattern holds across both infectious and non-infectious causes. The seasonal variation in heart disease deaths alone exceeds total influenza deaths during flu season.

Australia shows the same pattern, but shifted six months—deaths peak in July, their winter. Singapore, 80 miles from the equator with year-round sun, shows no seasonal mortality pattern.

Multiple studies have linked mortality rates to latitude, independent of vitamin D levels, suggesting sunlight itself—particularly its infrared component—plays a direct metabolic role.

Hospitals Are Bringing Patients Outside

Armed with mounting evidence, hospitals worldwide are redesigning care spaces to maximize sunlight exposure.

A $1.5 billion hospital in Footscray, Australia, built ICU beds with direct outdoor access. King’s College Hospital in London invested £2 million to transform its rooftop into a critical care garden where up to six ICU patients can receive treatment surrounded by greenery and natural light.

St. George’s Hospital in London followed suit, creating a neurointensive care rooftop unit. Queen Camilla visited the facility in 2026 to recognize the innovation.

Randomized controlled trials using infrared vests delivering roughly 20–30 watts per square meter (comparable to sitting under a tree) showed 30% reductions in ICU length of stay and improved muscle strength in critically ill COVID-19 patients.

Metabolic Scaling Matches Solar Power Scaling

One of the paper’s most intriguing observations: metabolic rate scales with body mass to the 3/4 power across species from flies to elephants.

Solar power intercepted by an organism also scales to the 3/4 power of mass—nearly identical.

This doesn’t prove causation, but it suggests sunlight could be a universal regulator of metabolic activity across the biosphere, with mitochondria in all organisms tuned to respond to the same infrared wavelengths present in Earth’s solar photon field.

What Makes This Hypothesis Different

Earlier theories proposed infrared light works by activating a photoreceptor in cytochrome c oxidase (complex IV) or by reducing water viscosity around ATP synthase motors.

Seheult’s team doesn’t reject these mechanisms—but argues they’re incomplete.

The Marcus framework explains phenomena earlier models couldn’t: why some infrared wavelengths inhibit rather than enhance mitochondrial activity, why broadband light outperforms monochromatic sources, and why effects persist across vastly different organisms.

The paper is the first to integrate four separate literature streams:

• Mitochondrial electron transfer follows Marcus physics
• Red and near-infrared light alter mitochondrial function
• Water and protein structures affect electron transfer kinetics
• Infrared radiation changes molecular electron transfer rates

“The novelty lies in the mechanistic integration,” Seheult emphasizes, “not in any single component.”

What Comes Next

The hypothesis is testable. Future experiments could measure how different infrared wavelengths alter specific Marcus crossing configurations in isolated mitochondrial complexes, or track real-time changes in reorganization energy using advanced spectroscopy.

If validated, the implications extend far beyond biology. Urban planning, architecture, workplace design, and lighting standards may all need reconsideration.

Seheult introduces a new term: photometabolism—solar-driven, non-photosynthetic modulation of core metabolic processes.

It’s a concept that positions sunlight not as a passive environmental factor, but as an active participant in the biochemistry of life itself.

I believe that this hypothesis if true has major implications for the built environment and how we live and the type of light that we require to live, and I believe it’s one of the major reasons why we need to be treating our patients outside.

Sources

• Jeffery et al. (2025) – Longer wavelengths in sunlight penetrating human tissue
• Ma et al. (2018) – Infrared perturbation of charge separation and recombination
• Sanderson et al. (2018) – Inhibitory modulation of cytochrome c oxidase with near-infrared wavelengths
• Dai et al. (2026) – Infrared stimulation of mitochondrial metabolism in deep-sea yeast
• Hayashi et al. (2010) – Water-mediated electron transfer in iron-sulfur bridges
• Marcus and Sutin (1985) – Electron transfer reactions in chemistry

Infrared light was making up for the cold temperatures by supplying vibrational activation rather than thermal activation.

Proteomics revealed the most upregulated protein after infrared exposure was a mitochondrial ribosomal protein (MRPs8), increased 6.7-fold.

Why Broadband Sunlight May Beat Monochromatic LEDs

Clinical studies using single-wavelength infrared devices have shown benefits—from reducing ICU length of stay to improving muscle strength in COVID-19 patients.

But Seheult’s hypothesis suggests broadband infrared from the sun may be even more effective.

“Sunlight contains a broad spectrum of wavelengths that can interact with many different vibrational modes and electron transfer steps,” he explains, “rather than targeting only one narrow pathway.”

Research from Jeffery’s lab supports this. When comparing monochromatic 850-nanometer light to a 60-watt incandescent bulb (which emits broad-spectrum infrared), the incandescent bulb produced greater improvements in color blindness.

• Monochromatic 850 nm: 9% improvement (head and body), 5% (body only)
• 60W incandescent bulb: 28% improvement, sustained for weeks

The research here aligns with the hypothesis, though direct mechanistic proof in human mitochondria remains to be demonstrated.

The Modern Indoor Environment: A Metabolic Desert?

LED bulbs emit virtually no infrared radiation. Low-emissivity (Low-E) glass windows, designed to improve energy efficiency, block infrared wavelengths.

Seheult measured infrared exposure in his own dining room with windows open: 0.8 watts per square meter.

Step outside under a shade tree with grass reflecting sunlight? 41.9 watts per square meter—more than 50 times higher.

We have set up a situation where outdoors we’re getting plenty of infrared light, versus being indoors where we have Low-E glass blocking it and LED bulbs producing none.

This raises profound questions about whether chronic infrared deficiency could contribute to the rising burden of metabolic diseases, especially among populations spending most of their time indoors.

Seasonal Mortality Patterns Point to Sunlight’s Role

Death rates from heart disease, cancer, stroke, Alzheimer’s, diabetes, and respiratory illness all peak one to three weeks after the shortest day of the year and bottom out after the longest day.

This pattern holds across both infectious and non-infectious causes. The seasonal variation in heart disease deaths alone exceeds total influenza deaths during flu season.

Australia shows the same pattern, but shifted six months—deaths peak in July, their winter. Singapore, 80 miles from the equator with year-round sun, shows no seasonal mortality pattern.

Multiple studies have linked mortality rates to latitude, independent of vitamin D levels, suggesting sunlight itself—particularly its infrared component—plays a direct metabolic role.

Hospitals Are Bringing Patients Outside

Armed with mounting evidence, hospitals worldwide are redesigning care spaces to maximize sunlight exposure.

A $1.5 billion hospital in Footscray, Australia, built ICU beds with direct outdoor access. King’s College Hospital in London invested £2 million to transform its rooftop into a critical care garden where up to six ICU patients can receive treatment surrounded by greenery and natural light.

St. George’s Hospital in London followed suit, creating a neurointensive care rooftop unit. Queen Camilla visited the facility in 2026 to recognize the innovation.

Randomized controlled trials using infrared vests delivering roughly 20–30 watts per square meter (comparable to sitting under a tree) showed 30% reductions in ICU length of stay and improved muscle strength in critically ill COVID-19 patients.

Metabolic Scaling Matches Solar Power Scaling

One of the paper’s most intriguing observations: metabolic rate scales with body mass to the 3/4 power across species from flies to elephants.

Solar power intercepted by an organism also scales to the 3/4 power of mass—nearly identical.

This doesn’t prove causation, but it suggests sunlight could be a universal regulator of metabolic activity across the biosphere, with mitochondria in all organisms tuned to respond to the same infrared wavelengths present in Earth’s solar photon field.

What Makes This Hypothesis Different

Earlier theories proposed infrared light works by activating a photoreceptor in cytochrome c oxidase (complex IV) or by reducing water viscosity around ATP synthase motors.

Seheult’s team doesn’t reject these mechanisms—but argues they’re incomplete.

The Marcus framework explains phenomena earlier models couldn’t: why some infrared wavelengths inhibit rather than enhance mitochondrial activity, why broadband light outperforms monochromatic sources, and why effects persist across vastly different organisms.

The paper is the first to integrate four separate literature streams:

• Mitochondrial electron transfer follows Marcus physics
• Red and near-infrared light alter mitochondrial function
• Water and protein structures affect electron transfer kinetics
• Infrared radiation changes molecular electron transfer rates

“The novelty lies in the mechanistic integration,” Seheult emphasizes, “not in any single component.”

What Comes Next

The hypothesis is testable. Future experiments could measure how different infrared wavelengths alter specific Marcus crossing configurations in isolated mitochondrial complexes, or track real-time changes in reorganization energy using advanced spectroscopy.

If validated, the implications extend far beyond biology. Urban planning, architecture, workplace design, and lighting standards may all need reconsideration.

Seheult introduces a new term: photometabolism—solar-driven, non-photosynthetic modulation of core metabolic processes.

It’s a concept that positions sunlight not as a passive environmental factor, but as an active participant in the biochemistry of life itself.

I believe that this hypothesis if true has major implications for the built environment and how we live and the type of light that we require to live, and I believe it’s one of the major reasons why we need to be treating our patients outside.

Sources

• Jeffery et al. (2025) – Longer wavelengths in sunlight penetrating human tissue
• Ma et al. (2018) – Infrared perturbation of charge separation and recombination
• Sanderson et al. (2018) – Inhibitory modulation of cytochrome c oxidase with near-infrared wavelengths
• Dai et al. (2026) – Infrared stimulation of mitochondrial metabolism in deep-sea yeast
• Hayashi et al. (2010) – Water-mediated electron transfer in iron-sulfur bridges
• Marcus and Sutin (1985) – Electron transfer reactions in chemistry

Infrared light was making up for the cold temperatures by supplying vibrational activation rather than thermal activation.

Proteomics revealed the most upregulated protein after infrared exposure was a mitochondrial ribosomal protein (MRPs8), increased 6.7-fold.

Why Broadband Sunlight May Beat Monochromatic LEDs

Clinical studies using single-wavelength infrared devices have shown benefits—from reducing ICU length of stay to improving muscle strength in COVID-19 patients.

But Seheult’s hypothesis suggests broadband infrared from the sun may be even more effective.

“Sunlight contains a broad spectrum of wavelengths that can interact with many different vibrational modes and electron transfer steps,” he explains, “rather than targeting only one narrow pathway.”

Research from Jeffery’s lab supports this. When comparing monochromatic 850-nanometer light to a 60-watt incandescent bulb (which emits broad-spectrum infrared), the incandescent bulb produced greater improvements in color blindness.

• Monochromatic 850 nm: 9% improvement (head and body), 5% (body only)
• 60W incandescent bulb: 28% improvement, sustained for weeks

The research here aligns with the hypothesis, though direct mechanistic proof in human mitochondria remains to be demonstrated.

The Modern Indoor Environment: A Metabolic Desert?

LED bulbs emit virtually no infrared radiation. Low-emissivity (Low-E) glass windows, designed to improve energy efficiency, block infrared wavelengths.

Seheult measured infrared exposure in his own dining room with windows open: 0.8 watts per square meter.

Step outside under a shade tree with grass reflecting sunlight? 41.9 watts per square meter—more than 50 times higher.

We have set up a situation where outdoors we’re getting plenty of infrared light, versus being indoors where we have Low-E glass blocking it and LED bulbs producing none.

This raises profound questions about whether chronic infrared deficiency could contribute to the rising burden of metabolic diseases, especially among populations spending most of their time indoors.

Seasonal Mortality Patterns Point to Sunlight’s Role

Death rates from heart disease, cancer, stroke, Alzheimer’s, diabetes, and respiratory illness all peak one to three weeks after the shortest day of the year and bottom out after the longest day.

This pattern holds across both infectious and non-infectious causes. The seasonal variation in heart disease deaths alone exceeds total influenza deaths during flu season.

Australia shows the same pattern, but shifted six months—deaths peak in July, their winter. Singapore, 80 miles from the equator with year-round sun, shows no seasonal mortality pattern.

Multiple studies have linked mortality rates to latitude, independent of vitamin D levels, suggesting sunlight itself—particularly its infrared component—plays a direct metabolic role.

Hospitals Are Bringing Patients Outside

Armed with mounting evidence, hospitals worldwide are redesigning care spaces to maximize sunlight exposure.

A $1.5 billion hospital in Footscray, Australia, built ICU beds with direct outdoor access. King’s College Hospital in London invested £2 million to transform its rooftop into a critical care garden where up to six ICU patients can receive treatment surrounded by greenery and natural light.

St. George’s Hospital in London followed suit, creating a neurointensive care rooftop unit. Queen Camilla visited the facility in 2026 to recognize the innovation.

Randomized controlled trials using infrared vests delivering roughly 20–30 watts per square meter (comparable to sitting under a tree) showed 30% reductions in ICU length of stay and improved muscle strength in critically ill COVID-19 patients.

Metabolic Scaling Matches Solar Power Scaling

One of the paper’s most intriguing observations: metabolic rate scales with body mass to the 3/4 power across species from flies to elephants.

Solar power intercepted by an organism also scales to the 3/4 power of mass—nearly identical.

This doesn’t prove causation, but it suggests sunlight could be a universal regulator of metabolic activity across the biosphere, with mitochondria in all organisms tuned to respond to the same infrared wavelengths present in Earth’s solar photon field.

What Makes This Hypothesis Different

Earlier theories proposed infrared light works by activating a photoreceptor in cytochrome c oxidase (complex IV) or by reducing water viscosity around ATP synthase motors.

Seheult’s team doesn’t reject these mechanisms—but argues they’re incomplete.

The Marcus framework explains phenomena earlier models couldn’t: why some infrared wavelengths inhibit rather than enhance mitochondrial activity, why broadband light outperforms monochromatic sources, and why effects persist across vastly different organisms.

The paper is the first to integrate four separate literature streams:

• Mitochondrial electron transfer follows Marcus physics
• Red and near-infrared light alter mitochondrial function
• Water and protein structures affect electron transfer kinetics
• Infrared radiation changes molecular electron transfer rates

“The novelty lies in the mechanistic integration,” Seheult emphasizes, “not in any single component.”

What Comes Next

The hypothesis is testable. Future experiments could measure how different infrared wavelengths alter specific Marcus crossing configurations in isolated mitochondrial complexes, or track real-time changes in reorganization energy using advanced spectroscopy.

If validated, the implications extend far beyond biology. Urban planning, architecture, workplace design, and lighting standards may all need reconsideration.

Seheult introduces a new term: photometabolism—solar-driven, non-photosynthetic modulation of core metabolic processes.

It’s a concept that positions sunlight not as a passive environmental factor, but as an active participant in the biochemistry of life itself.

I believe that this hypothesis if true has major implications for the built environment and how we live and the type of light that we require to live, and I believe it’s one of the major reasons why we need to be treating our patients outside.

Sources

• Jeffery et al. (2025) – Longer wavelengths in sunlight penetrating human tissue
• Ma et al. (2018) – Infrared perturbation of charge separation and recombination
• Sanderson et al. (2018) – Inhibitory modulation of cytochrome c oxidase with near-infrared wavelengths
• Dai et al. (2026) – Infrared stimulation of mitochondrial metabolism in deep-sea yeast
• Hayashi et al. (2010) – Water-mediated electron transfer in iron-sulfur bridges
• Marcus and Sutin (1985) – Electron transfer reactions in chemistry

At 20°C, yeast exposed to 880-nanometer light grew vigorously while dark controls showed minimal activity. The effective activation energy dropped from 12 kilocalories per mole to just 2 kilocalories per mole.

Infrared light was making up for the cold temperatures by supplying vibrational activation rather than thermal activation.

Proteomics revealed the most upregulated protein after infrared exposure was a mitochondrial ribosomal protein (MRPs8), increased 6.7-fold.

Why Broadband Sunlight May Beat Monochromatic LEDs

Clinical studies using single-wavelength infrared devices have shown benefits—from reducing ICU length of stay to improving muscle strength in COVID-19 patients.

But Seheult’s hypothesis suggests broadband infrared from the sun may be even more effective.

“Sunlight contains a broad spectrum of wavelengths that can interact with many different vibrational modes and electron transfer steps,” he explains, “rather than targeting only one narrow pathway.”

Research from Jeffery’s lab supports this. When comparing monochromatic 850-nanometer light to a 60-watt incandescent bulb (which emits broad-spectrum infrared), the incandescent bulb produced greater improvements in color blindness.

• Monochromatic 850 nm: 9% improvement (head and body), 5% (body only)
• 60W incandescent bulb: 28% improvement, sustained for weeks

The research here aligns with the hypothesis, though direct mechanistic proof in human mitochondria remains to be demonstrated.

The Modern Indoor Environment: A Metabolic Desert?

LED bulbs emit virtually no infrared radiation. Low-emissivity (Low-E) glass windows, designed to improve energy efficiency, block infrared wavelengths.

Seheult measured infrared exposure in his own dining room with windows open: 0.8 watts per square meter.

Step outside under a shade tree with grass reflecting sunlight? 41.9 watts per square meter—more than 50 times higher.

We have set up a situation where outdoors we’re getting plenty of infrared light, versus being indoors where we have Low-E glass blocking it and LED bulbs producing none.

This raises profound questions about whether chronic infrared deficiency could contribute to the rising burden of metabolic diseases, especially among populations spending most of their time indoors.

Seasonal Mortality Patterns Point to Sunlight’s Role

Death rates from heart disease, cancer, stroke, Alzheimer’s, diabetes, and respiratory illness all peak one to three weeks after the shortest day of the year and bottom out after the longest day.

This pattern holds across both infectious and non-infectious causes. The seasonal variation in heart disease deaths alone exceeds total influenza deaths during flu season.

Australia shows the same pattern, but shifted six months—deaths peak in July, their winter. Singapore, 80 miles from the equator with year-round sun, shows no seasonal mortality pattern.

Multiple studies have linked mortality rates to latitude, independent of vitamin D levels, suggesting sunlight itself—particularly its infrared component—plays a direct metabolic role.

Hospitals Are Bringing Patients Outside

Armed with mounting evidence, hospitals worldwide are redesigning care spaces to maximize sunlight exposure.

A $1.5 billion hospital in Footscray, Australia, built ICU beds with direct outdoor access. King’s College Hospital in London invested £2 million to transform its rooftop into a critical care garden where up to six ICU patients can receive treatment surrounded by greenery and natural light.

St. George’s Hospital in London followed suit, creating a neurointensive care rooftop unit. Queen Camilla visited the facility in 2026 to recognize the innovation.

Randomized controlled trials using infrared vests delivering roughly 20–30 watts per square meter (comparable to sitting under a tree) showed 30% reductions in ICU length of stay and improved muscle strength in critically ill COVID-19 patients.

Metabolic Scaling Matches Solar Power Scaling

One of the paper’s most intriguing observations: metabolic rate scales with body mass to the 3/4 power across species from flies to elephants.

Solar power intercepted by an organism also scales to the 3/4 power of mass—nearly identical.

This doesn’t prove causation, but it suggests sunlight could be a universal regulator of metabolic activity across the biosphere, with mitochondria in all organisms tuned to respond to the same infrared wavelengths present in Earth’s solar photon field.

What Makes This Hypothesis Different

Earlier theories proposed infrared light works by activating a photoreceptor in cytochrome c oxidase (complex IV) or by reducing water viscosity around ATP synthase motors.

Seheult’s team doesn’t reject these mechanisms—but argues they’re incomplete.

The Marcus framework explains phenomena earlier models couldn’t: why some infrared wavelengths inhibit rather than enhance mitochondrial activity, why broadband light outperforms monochromatic sources, and why effects persist across vastly different organisms.

The paper is the first to integrate four separate literature streams:

• Mitochondrial electron transfer follows Marcus physics
• Red and near-infrared light alter mitochondrial function
• Water and protein structures affect electron transfer kinetics
• Infrared radiation changes molecular electron transfer rates

“The novelty lies in the mechanistic integration,” Seheult emphasizes, “not in any single component.”

What Comes Next

The hypothesis is testable. Future experiments could measure how different infrared wavelengths alter specific Marcus crossing configurations in isolated mitochondrial complexes, or track real-time changes in reorganization energy using advanced spectroscopy.

If validated, the implications extend far beyond biology. Urban planning, architecture, workplace design, and lighting standards may all need reconsideration.

Seheult introduces a new term: photometabolism—solar-driven, non-photosynthetic modulation of core metabolic processes.

It’s a concept that positions sunlight not as a passive environmental factor, but as an active participant in the biochemistry of life itself.

I believe that this hypothesis if true has major implications for the built environment and how we live and the type of light that we require to live, and I believe it’s one of the major reasons why we need to be treating our patients outside.

Sources

• Jeffery et al. (2025) – Longer wavelengths in sunlight penetrating human tissue
• Ma et al. (2018) – Infrared perturbation of charge separation and recombination
• Sanderson et al. (2018) – Inhibitory modulation of cytochrome c oxidase with near-infrared wavelengths
• Dai et al. (2026) – Infrared stimulation of mitochondrial metabolism in deep-sea yeast
• Hayashi et al. (2010) – Water-mediated electron transfer in iron-sulfur bridges
• Marcus and Sutin (1985) – Electron transfer reactions in chemistry

At 20°C, yeast exposed to 880-nanometer light grew vigorously while dark controls showed minimal activity. The effective activation energy dropped from 12 kilocalories per mole to just 2 kilocalories per mole.

Infrared light was making up for the cold temperatures by supplying vibrational activation rather than thermal activation.

Proteomics revealed the most upregulated protein after infrared exposure was a mitochondrial ribosomal protein (MRPs8), increased 6.7-fold.

Why Broadband Sunlight May Beat Monochromatic LEDs

Clinical studies using single-wavelength infrared devices have shown benefits—from reducing ICU length of stay to improving muscle strength in COVID-19 patients.

But Seheult’s hypothesis suggests broadband infrared from the sun may be even more effective.

“Sunlight contains a broad spectrum of wavelengths that can interact with many different vibrational modes and electron transfer steps,” he explains, “rather than targeting only one narrow pathway.”

Research from Jeffery’s lab supports this. When comparing monochromatic 850-nanometer light to a 60-watt incandescent bulb (which emits broad-spectrum infrared), the incandescent bulb produced greater improvements in color blindness.

• Monochromatic 850 nm: 9% improvement (head and body), 5% (body only)
• 60W incandescent bulb: 28% improvement, sustained for weeks

The research here aligns with the hypothesis, though direct mechanistic proof in human mitochondria remains to be demonstrated.

The Modern Indoor Environment: A Metabolic Desert?

LED bulbs emit virtually no infrared radiation. Low-emissivity (Low-E) glass windows, designed to improve energy efficiency, block infrared wavelengths.

Seheult measured infrared exposure in his own dining room with windows open: 0.8 watts per square meter.

Step outside under a shade tree with grass reflecting sunlight? 41.9 watts per square meter—more than 50 times higher.

We have set up a situation where outdoors we’re getting plenty of infrared light, versus being indoors where we have Low-E glass blocking it and LED bulbs producing none.

This raises profound questions about whether chronic infrared deficiency could contribute to the rising burden of metabolic diseases, especially among populations spending most of their time indoors.

Seasonal Mortality Patterns Point to Sunlight’s Role

Death rates from heart disease, cancer, stroke, Alzheimer’s, diabetes, and respiratory illness all peak one to three weeks after the shortest day of the year and bottom out after the longest day.

This pattern holds across both infectious and non-infectious causes. The seasonal variation in heart disease deaths alone exceeds total influenza deaths during flu season.

Australia shows the same pattern, but shifted six months—deaths peak in July, their winter. Singapore, 80 miles from the equator with year-round sun, shows no seasonal mortality pattern.

Multiple studies have linked mortality rates to latitude, independent of vitamin D levels, suggesting sunlight itself—particularly its infrared component—plays a direct metabolic role.

Hospitals Are Bringing Patients Outside

Armed with mounting evidence, hospitals worldwide are redesigning care spaces to maximize sunlight exposure.

A $1.5 billion hospital in Footscray, Australia, built ICU beds with direct outdoor access. King’s College Hospital in London invested £2 million to transform its rooftop into a critical care garden where up to six ICU patients can receive treatment surrounded by greenery and natural light.

St. George’s Hospital in London followed suit, creating a neurointensive care rooftop unit. Queen Camilla visited the facility in 2026 to recognize the innovation.

Randomized controlled trials using infrared vests delivering roughly 20–30 watts per square meter (comparable to sitting under a tree) showed 30% reductions in ICU length of stay and improved muscle strength in critically ill COVID-19 patients.

Metabolic Scaling Matches Solar Power Scaling

One of the paper’s most intriguing observations: metabolic rate scales with body mass to the 3/4 power across species from flies to elephants.

Solar power intercepted by an organism also scales to the 3/4 power of mass—nearly identical.

This doesn’t prove causation, but it suggests sunlight could be a universal regulator of metabolic activity across the biosphere, with mitochondria in all organisms tuned to respond to the same infrared wavelengths present in Earth’s solar photon field.

What Makes This Hypothesis Different

Earlier theories proposed infrared light works by activating a photoreceptor in cytochrome c oxidase (complex IV) or by reducing water viscosity around ATP synthase motors.

Seheult’s team doesn’t reject these mechanisms—but argues they’re incomplete.

The Marcus framework explains phenomena earlier models couldn’t: why some infrared wavelengths inhibit rather than enhance mitochondrial activity, why broadband light outperforms monochromatic sources, and why effects persist across vastly different organisms.

The paper is the first to integrate four separate literature streams:

• Mitochondrial electron transfer follows Marcus physics
• Red and near-infrared light alter mitochondrial function
• Water and protein structures affect electron transfer kinetics
• Infrared radiation changes molecular electron transfer rates

“The novelty lies in the mechanistic integration,” Seheult emphasizes, “not in any single component.”

What Comes Next

The hypothesis is testable. Future experiments could measure how different infrared wavelengths alter specific Marcus crossing configurations in isolated mitochondrial complexes, or track real-time changes in reorganization energy using advanced spectroscopy.

If validated, the implications extend far beyond biology. Urban planning, architecture, workplace design, and lighting standards may all need reconsideration.

Seheult introduces a new term: photometabolism—solar-driven, non-photosynthetic modulation of core metabolic processes.

It’s a concept that positions sunlight not as a passive environmental factor, but as an active participant in the biochemistry of life itself.

I believe that this hypothesis if true has major implications for the built environment and how we live and the type of light that we require to live, and I believe it’s one of the major reasons why we need to be treating our patients outside.

Sources

• Jeffery et al. (2025) – Longer wavelengths in sunlight penetrating human tissue
• Ma et al. (2018) – Infrared perturbation of charge separation and recombination
• Sanderson et al. (2018) – Inhibitory modulation of cytochrome c oxidase with near-infrared wavelengths
• Dai et al. (2026) – Infrared stimulation of mitochondrial metabolism in deep-sea yeast
• Hayashi et al. (2010) – Water-mediated electron transfer in iron-sulfur bridges
• Marcus and Sutin (1985) – Electron transfer reactions in chemistry

Even more remarkable: infrared light allowed yeast to grow at cooler temperatures where dark controls remained dormant.

At 20°C, yeast exposed to 880-nanometer light grew vigorously while dark controls showed minimal activity. The effective activation energy dropped from 12 kilocalories per mole to just 2 kilocalories per mole.

Infrared light was making up for the cold temperatures by supplying vibrational activation rather than thermal activation.

Proteomics revealed the most upregulated protein after infrared exposure was a mitochondrial ribosomal protein (MRPs8), increased 6.7-fold.

Why Broadband Sunlight May Beat Monochromatic LEDs

Clinical studies using single-wavelength infrared devices have shown benefits—from reducing ICU length of stay to improving muscle strength in COVID-19 patients.

But Seheult’s hypothesis suggests broadband infrared from the sun may be even more effective.

“Sunlight contains a broad spectrum of wavelengths that can interact with many different vibrational modes and electron transfer steps,” he explains, “rather than targeting only one narrow pathway.”

Research from Jeffery’s lab supports this. When comparing monochromatic 850-nanometer light to a 60-watt incandescent bulb (which emits broad-spectrum infrared), the incandescent bulb produced greater improvements in color blindness.

• Monochromatic 850 nm: 9% improvement (head and body), 5% (body only)
• 60W incandescent bulb: 28% improvement, sustained for weeks

The research here aligns with the hypothesis, though direct mechanistic proof in human mitochondria remains to be demonstrated.

The Modern Indoor Environment: A Metabolic Desert?

LED bulbs emit virtually no infrared radiation. Low-emissivity (Low-E) glass windows, designed to improve energy efficiency, block infrared wavelengths.

Seheult measured infrared exposure in his own dining room with windows open: 0.8 watts per square meter.

Step outside under a shade tree with grass reflecting sunlight? 41.9 watts per square meter—more than 50 times higher.

We have set up a situation where outdoors we’re getting plenty of infrared light, versus being indoors where we have Low-E glass blocking it and LED bulbs producing none.

This raises profound questions about whether chronic infrared deficiency could contribute to the rising burden of metabolic diseases, especially among populations spending most of their time indoors.

Seasonal Mortality Patterns Point to Sunlight’s Role

Death rates from heart disease, cancer, stroke, Alzheimer’s, diabetes, and respiratory illness all peak one to three weeks after the shortest day of the year and bottom out after the longest day.

This pattern holds across both infectious and non-infectious causes. The seasonal variation in heart disease deaths alone exceeds total influenza deaths during flu season.

Australia shows the same pattern, but shifted six months—deaths peak in July, their winter. Singapore, 80 miles from the equator with year-round sun, shows no seasonal mortality pattern.

Multiple studies have linked mortality rates to latitude, independent of vitamin D levels, suggesting sunlight itself—particularly its infrared component—plays a direct metabolic role.

Hospitals Are Bringing Patients Outside

Armed with mounting evidence, hospitals worldwide are redesigning care spaces to maximize sunlight exposure.

A $1.5 billion hospital in Footscray, Australia, built ICU beds with direct outdoor access. King’s College Hospital in London invested £2 million to transform its rooftop into a critical care garden where up to six ICU patients can receive treatment surrounded by greenery and natural light.

St. George’s Hospital in London followed suit, creating a neurointensive care rooftop unit. Queen Camilla visited the facility in 2026 to recognize the innovation.

Randomized controlled trials using infrared vests delivering roughly 20–30 watts per square meter (comparable to sitting under a tree) showed 30% reductions in ICU length of stay and improved muscle strength in critically ill COVID-19 patients.

Metabolic Scaling Matches Solar Power Scaling

One of the paper’s most intriguing observations: metabolic rate scales with body mass to the 3/4 power across species from flies to elephants.

Solar power intercepted by an organism also scales to the 3/4 power of mass—nearly identical.

This doesn’t prove causation, but it suggests sunlight could be a universal regulator of metabolic activity across the biosphere, with mitochondria in all organisms tuned to respond to the same infrared wavelengths present in Earth’s solar photon field.

What Makes This Hypothesis Different

Earlier theories proposed infrared light works by activating a photoreceptor in cytochrome c oxidase (complex IV) or by reducing water viscosity around ATP synthase motors.

Seheult’s team doesn’t reject these mechanisms—but argues they’re incomplete.

The Marcus framework explains phenomena earlier models couldn’t: why some infrared wavelengths inhibit rather than enhance mitochondrial activity, why broadband light outperforms monochromatic sources, and why effects persist across vastly different organisms.

The paper is the first to integrate four separate literature streams:

• Mitochondrial electron transfer follows Marcus physics
• Red and near-infrared light alter mitochondrial function
• Water and protein structures affect electron transfer kinetics
• Infrared radiation changes molecular electron transfer rates

“The novelty lies in the mechanistic integration,” Seheult emphasizes, “not in any single component.”

What Comes Next

The hypothesis is testable. Future experiments could measure how different infrared wavelengths alter specific Marcus crossing configurations in isolated mitochondrial complexes, or track real-time changes in reorganization energy using advanced spectroscopy.

If validated, the implications extend far beyond biology. Urban planning, architecture, workplace design, and lighting standards may all need reconsideration.

Seheult introduces a new term: photometabolism—solar-driven, non-photosynthetic modulation of core metabolic processes.

It’s a concept that positions sunlight not as a passive environmental factor, but as an active participant in the biochemistry of life itself.

I believe that this hypothesis if true has major implications for the built environment and how we live and the type of light that we require to live, and I believe it’s one of the major reasons why we need to be treating our patients outside.

Sources

• Jeffery et al. (2025) – Longer wavelengths in sunlight penetrating human tissue
• Ma et al. (2018) – Infrared perturbation of charge separation and recombination
• Sanderson et al. (2018) – Inhibitory modulation of cytochrome c oxidase with near-infrared wavelengths
• Dai et al. (2026) – Infrared stimulation of mitochondrial metabolism in deep-sea yeast
• Hayashi et al. (2010) – Water-mediated electron transfer in iron-sulfur bridges
• Marcus and Sutin (1985) – Electron transfer reactions in chemistry

Even more remarkable: infrared light allowed yeast to grow at cooler temperatures where dark controls remained dormant.

At 20°C, yeast exposed to 880-nanometer light grew vigorously while dark controls showed minimal activity. The effective activation energy dropped from 12 kilocalories per mole to just 2 kilocalories per mole.

Infrared light was making up for the cold temperatures by supplying vibrational activation rather than thermal activation.

Proteomics revealed the most upregulated protein after infrared exposure was a mitochondrial ribosomal protein (MRPs8), increased 6.7-fold.

Why Broadband Sunlight May Beat Monochromatic LEDs

Clinical studies using single-wavelength infrared devices have shown benefits—from reducing ICU length of stay to improving muscle strength in COVID-19 patients.

But Seheult’s hypothesis suggests broadband infrared from the sun may be even more effective.

“Sunlight contains a broad spectrum of wavelengths that can interact with many different vibrational modes and electron transfer steps,” he explains, “rather than targeting only one narrow pathway.”

Research from Jeffery’s lab supports this. When comparing monochromatic 850-nanometer light to a 60-watt incandescent bulb (which emits broad-spectrum infrared), the incandescent bulb produced greater improvements in color blindness.

• Monochromatic 850 nm: 9% improvement (head and body), 5% (body only)
• 60W incandescent bulb: 28% improvement, sustained for weeks

The research here aligns with the hypothesis, though direct mechanistic proof in human mitochondria remains to be demonstrated.

The Modern Indoor Environment: A Metabolic Desert?

LED bulbs emit virtually no infrared radiation. Low-emissivity (Low-E) glass windows, designed to improve energy efficiency, block infrared wavelengths.

Seheult measured infrared exposure in his own dining room with windows open: 0.8 watts per square meter.

Step outside under a shade tree with grass reflecting sunlight? 41.9 watts per square meter—more than 50 times higher.

We have set up a situation where outdoors we’re getting plenty of infrared light, versus being indoors where we have Low-E glass blocking it and LED bulbs producing none.

This raises profound questions about whether chronic infrared deficiency could contribute to the rising burden of metabolic diseases, especially among populations spending most of their time indoors.

Seasonal Mortality Patterns Point to Sunlight’s Role

Death rates from heart disease, cancer, stroke, Alzheimer’s, diabetes, and respiratory illness all peak one to three weeks after the shortest day of the year and bottom out after the longest day.

This pattern holds across both infectious and non-infectious causes. The seasonal variation in heart disease deaths alone exceeds total influenza deaths during flu season.

Australia shows the same pattern, but shifted six months—deaths peak in July, their winter. Singapore, 80 miles from the equator with year-round sun, shows no seasonal mortality pattern.

Multiple studies have linked mortality rates to latitude, independent of vitamin D levels, suggesting sunlight itself—particularly its infrared component—plays a direct metabolic role.

Hospitals Are Bringing Patients Outside

Armed with mounting evidence, hospitals worldwide are redesigning care spaces to maximize sunlight exposure.

A $1.5 billion hospital in Footscray, Australia, built ICU beds with direct outdoor access. King’s College Hospital in London invested £2 million to transform its rooftop into a critical care garden where up to six ICU patients can receive treatment surrounded by greenery and natural light.

St. George’s Hospital in London followed suit, creating a neurointensive care rooftop unit. Queen Camilla visited the facility in 2026 to recognize the innovation.

Randomized controlled trials using infrared vests delivering roughly 20–30 watts per square meter (comparable to sitting under a tree) showed 30% reductions in ICU length of stay and improved muscle strength in critically ill COVID-19 patients.

Metabolic Scaling Matches Solar Power Scaling

One of the paper’s most intriguing observations: metabolic rate scales with body mass to the 3/4 power across species from flies to elephants.

Solar power intercepted by an organism also scales to the 3/4 power of mass—nearly identical.

This doesn’t prove causation, but it suggests sunlight could be a universal regulator of metabolic activity across the biosphere, with mitochondria in all organisms tuned to respond to the same infrared wavelengths present in Earth’s solar photon field.

What Makes This Hypothesis Different

Earlier theories proposed infrared light works by activating a photoreceptor in cytochrome c oxidase (complex IV) or by reducing water viscosity around ATP synthase motors.

Seheult’s team doesn’t reject these mechanisms—but argues they’re incomplete.

The Marcus framework explains phenomena earlier models couldn’t: why some infrared wavelengths inhibit rather than enhance mitochondrial activity, why broadband light outperforms monochromatic sources, and why effects persist across vastly different organisms.

The paper is the first to integrate four separate literature streams:

• Mitochondrial electron transfer follows Marcus physics
• Red and near-infrared light alter mitochondrial function
• Water and protein structures affect electron transfer kinetics
• Infrared radiation changes molecular electron transfer rates

“The novelty lies in the mechanistic integration,” Seheult emphasizes, “not in any single component.”

What Comes Next

The hypothesis is testable. Future experiments could measure how different infrared wavelengths alter specific Marcus crossing configurations in isolated mitochondrial complexes, or track real-time changes in reorganization energy using advanced spectroscopy.

If validated, the implications extend far beyond biology. Urban planning, architecture, workplace design, and lighting standards may all need reconsideration.

Seheult introduces a new term: photometabolism—solar-driven, non-photosynthetic modulation of core metabolic processes.

It’s a concept that positions sunlight not as a passive environmental factor, but as an active participant in the biochemistry of life itself.

I believe that this hypothesis if true has major implications for the built environment and how we live and the type of light that we require to live, and I believe it’s one of the major reasons why we need to be treating our patients outside.

Sources

• Jeffery et al. (2025) – Longer wavelengths in sunlight penetrating human tissue
• Ma et al. (2018) – Infrared perturbation of charge separation and recombination
• Sanderson et al. (2018) – Inhibitory modulation of cytochrome c oxidase with near-infrared wavelengths
• Dai et al. (2026) – Infrared stimulation of mitochondrial metabolism in deep-sea yeast
• Hayashi et al. (2010) – Water-mediated electron transfer in iron-sulfur bridges
• Marcus and Sutin (1985) – Electron transfer reactions in chemistry

Cold Temperatures, Warm Light

Even more remarkable: infrared light allowed yeast to grow at cooler temperatures where dark controls remained dormant.

At 20°C, yeast exposed to 880-nanometer light grew vigorously while dark controls showed minimal activity. The effective activation energy dropped from 12 kilocalories per mole to just 2 kilocalories per mole.

Infrared light was making up for the cold temperatures by supplying vibrational activation rather than thermal activation.

Proteomics revealed the most upregulated protein after infrared exposure was a mitochondrial ribosomal protein (MRPs8), increased 6.7-fold.

Why Broadband Sunlight May Beat Monochromatic LEDs

Clinical studies using single-wavelength infrared devices have shown benefits—from reducing ICU length of stay to improving muscle strength in COVID-19 patients.

But Seheult’s hypothesis suggests broadband infrared from the sun may be even more effective.

“Sunlight contains a broad spectrum of wavelengths that can interact with many different vibrational modes and electron transfer steps,” he explains, “rather than targeting only one narrow pathway.”

Research from Jeffery’s lab supports this. When comparing monochromatic 850-nanometer light to a 60-watt incandescent bulb (which emits broad-spectrum infrared), the incandescent bulb produced greater improvements in color blindness.

• Monochromatic 850 nm: 9% improvement (head and body), 5% (body only)
• 60W incandescent bulb: 28% improvement, sustained for weeks

The research here aligns with the hypothesis, though direct mechanistic proof in human mitochondria remains to be demonstrated.

The Modern Indoor Environment: A Metabolic Desert?

LED bulbs emit virtually no infrared radiation. Low-emissivity (Low-E) glass windows, designed to improve energy efficiency, block infrared wavelengths.

Seheult measured infrared exposure in his own dining room with windows open: 0.8 watts per square meter.

Step outside under a shade tree with grass reflecting sunlight? 41.9 watts per square meter—more than 50 times higher.

We have set up a situation where outdoors we’re getting plenty of infrared light, versus being indoors where we have Low-E glass blocking it and LED bulbs producing none.

This raises profound questions about whether chronic infrared deficiency could contribute to the rising burden of metabolic diseases, especially among populations spending most of their time indoors.

Seasonal Mortality Patterns Point to Sunlight’s Role

Death rates from heart disease, cancer, stroke, Alzheimer’s, diabetes, and respiratory illness all peak one to three weeks after the shortest day of the year and bottom out after the longest day.

This pattern holds across both infectious and non-infectious causes. The seasonal variation in heart disease deaths alone exceeds total influenza deaths during flu season.

Australia shows the same pattern, but shifted six months—deaths peak in July, their winter. Singapore, 80 miles from the equator with year-round sun, shows no seasonal mortality pattern.

Multiple studies have linked mortality rates to latitude, independent of vitamin D levels, suggesting sunlight itself—particularly its infrared component—plays a direct metabolic role.

Hospitals Are Bringing Patients Outside

Armed with mounting evidence, hospitals worldwide are redesigning care spaces to maximize sunlight exposure.

A $1.5 billion hospital in Footscray, Australia, built ICU beds with direct outdoor access. King’s College Hospital in London invested £2 million to transform its rooftop into a critical care garden where up to six ICU patients can receive treatment surrounded by greenery and natural light.

St. George’s Hospital in London followed suit, creating a neurointensive care rooftop unit. Queen Camilla visited the facility in 2026 to recognize the innovation.

Randomized controlled trials using infrared vests delivering roughly 20–30 watts per square meter (comparable to sitting under a tree) showed 30% reductions in ICU length of stay and improved muscle strength in critically ill COVID-19 patients.

Metabolic Scaling Matches Solar Power Scaling

One of the paper’s most intriguing observations: metabolic rate scales with body mass to the 3/4 power across species from flies to elephants.

Solar power intercepted by an organism also scales to the 3/4 power of mass—nearly identical.

This doesn’t prove causation, but it suggests sunlight could be a universal regulator of metabolic activity across the biosphere, with mitochondria in all organisms tuned to respond to the same infrared wavelengths present in Earth’s solar photon field.

What Makes This Hypothesis Different

Earlier theories proposed infrared light works by activating a photoreceptor in cytochrome c oxidase (complex IV) or by reducing water viscosity around ATP synthase motors.

Seheult’s team doesn’t reject these mechanisms—but argues they’re incomplete.

The Marcus framework explains phenomena earlier models couldn’t: why some infrared wavelengths inhibit rather than enhance mitochondrial activity, why broadband light outperforms monochromatic sources, and why effects persist across vastly different organisms.

The paper is the first to integrate four separate literature streams:

• Mitochondrial electron transfer follows Marcus physics
• Red and near-infrared light alter mitochondrial function
• Water and protein structures affect electron transfer kinetics
• Infrared radiation changes molecular electron transfer rates

“The novelty lies in the mechanistic integration,” Seheult emphasizes, “not in any single component.”

What Comes Next

The hypothesis is testable. Future experiments could measure how different infrared wavelengths alter specific Marcus crossing configurations in isolated mitochondrial complexes, or track real-time changes in reorganization energy using advanced spectroscopy.

If validated, the implications extend far beyond biology. Urban planning, architecture, workplace design, and lighting standards may all need reconsideration.

Seheult introduces a new term: photometabolism—solar-driven, non-photosynthetic modulation of core metabolic processes.

It’s a concept that positions sunlight not as a passive environmental factor, but as an active participant in the biochemistry of life itself.

I believe that this hypothesis if true has major implications for the built environment and how we live and the type of light that we require to live, and I believe it’s one of the major reasons why we need to be treating our patients outside.

Sources

• Jeffery et al. (2025) – Longer wavelengths in sunlight penetrating human tissue
• Ma et al. (2018) – Infrared perturbation of charge separation and recombination
• Sanderson et al. (2018) – Inhibitory modulation of cytochrome c oxidase with near-infrared wavelengths
• Dai et al. (2026) – Infrared stimulation of mitochondrial metabolism in deep-sea yeast
• Hayashi et al. (2010) – Water-mediated electron transfer in iron-sulfur bridges
• Marcus and Sutin (1985) – Electron transfer reactions in chemistry

Cold Temperatures, Warm Light

Even more remarkable: infrared light allowed yeast to grow at cooler temperatures where dark controls remained dormant.

At 20°C, yeast exposed to 880-nanometer light grew vigorously while dark controls showed minimal activity. The effective activation energy dropped from 12 kilocalories per mole to just 2 kilocalories per mole.

Infrared light was making up for the cold temperatures by supplying vibrational activation rather than thermal activation.

Proteomics revealed the most upregulated protein after infrared exposure was a mitochondrial ribosomal protein (MRPs8), increased 6.7-fold.

Why Broadband Sunlight May Beat Monochromatic LEDs

Clinical studies using single-wavelength infrared devices have shown benefits—from reducing ICU length of stay to improving muscle strength in COVID-19 patients.

But Seheult’s hypothesis suggests broadband infrared from the sun may be even more effective.

“Sunlight contains a broad spectrum of wavelengths that can interact with many different vibrational modes and electron transfer steps,” he explains, “rather than targeting only one narrow pathway.”

Research from Jeffery’s lab supports this. When comparing monochromatic 850-nanometer light to a 60-watt incandescent bulb (which emits broad-spectrum infrared), the incandescent bulb produced greater improvements in color blindness.

• Monochromatic 850 nm: 9% improvement (head and body), 5% (body only)
• 60W incandescent bulb: 28% improvement, sustained for weeks

The research here aligns with the hypothesis, though direct mechanistic proof in human mitochondria remains to be demonstrated.

The Modern Indoor Environment: A Metabolic Desert?

LED bulbs emit virtually no infrared radiation. Low-emissivity (Low-E) glass windows, designed to improve energy efficiency, block infrared wavelengths.

Seheult measured infrared exposure in his own dining room with windows open: 0.8 watts per square meter.

Step outside under a shade tree with grass reflecting sunlight? 41.9 watts per square meter—more than 50 times higher.

We have set up a situation where outdoors we’re getting plenty of infrared light, versus being indoors where we have Low-E glass blocking it and LED bulbs producing none.

This raises profound questions about whether chronic infrared deficiency could contribute to the rising burden of metabolic diseases, especially among populations spending most of their time indoors.

Seasonal Mortality Patterns Point to Sunlight’s Role

Death rates from heart disease, cancer, stroke, Alzheimer’s, diabetes, and respiratory illness all peak one to three weeks after the shortest day of the year and bottom out after the longest day.

This pattern holds across both infectious and non-infectious causes. The seasonal variation in heart disease deaths alone exceeds total influenza deaths during flu season.

Australia shows the same pattern, but shifted six months—deaths peak in July, their winter. Singapore, 80 miles from the equator with year-round sun, shows no seasonal mortality pattern.

Multiple studies have linked mortality rates to latitude, independent of vitamin D levels, suggesting sunlight itself—particularly its infrared component—plays a direct metabolic role.

Hospitals Are Bringing Patients Outside

Armed with mounting evidence, hospitals worldwide are redesigning care spaces to maximize sunlight exposure.

A $1.5 billion hospital in Footscray, Australia, built ICU beds with direct outdoor access. King’s College Hospital in London invested £2 million to transform its rooftop into a critical care garden where up to six ICU patients can receive treatment surrounded by greenery and natural light.

St. George’s Hospital in London followed suit, creating a neurointensive care rooftop unit. Queen Camilla visited the facility in 2026 to recognize the innovation.

Randomized controlled trials using infrared vests delivering roughly 20–30 watts per square meter (comparable to sitting under a tree) showed 30% reductions in ICU length of stay and improved muscle strength in critically ill COVID-19 patients.

Metabolic Scaling Matches Solar Power Scaling

One of the paper’s most intriguing observations: metabolic rate scales with body mass to the 3/4 power across species from flies to elephants.

Solar power intercepted by an organism also scales to the 3/4 power of mass—nearly identical.

This doesn’t prove causation, but it suggests sunlight could be a universal regulator of metabolic activity across the biosphere, with mitochondria in all organisms tuned to respond to the same infrared wavelengths present in Earth’s solar photon field.

What Makes This Hypothesis Different

Earlier theories proposed infrared light works by activating a photoreceptor in cytochrome c oxidase (complex IV) or by reducing water viscosity around ATP synthase motors.

Seheult’s team doesn’t reject these mechanisms—but argues they’re incomplete.

The Marcus framework explains phenomena earlier models couldn’t: why some infrared wavelengths inhibit rather than enhance mitochondrial activity, why broadband light outperforms monochromatic sources, and why effects persist across vastly different organisms.

The paper is the first to integrate four separate literature streams:

• Mitochondrial electron transfer follows Marcus physics
• Red and near-infrared light alter mitochondrial function
• Water and protein structures affect electron transfer kinetics
• Infrared radiation changes molecular electron transfer rates

“The novelty lies in the mechanistic integration,” Seheult emphasizes, “not in any single component.”

What Comes Next

The hypothesis is testable. Future experiments could measure how different infrared wavelengths alter specific Marcus crossing configurations in isolated mitochondrial complexes, or track real-time changes in reorganization energy using advanced spectroscopy.

If validated, the implications extend far beyond biology. Urban planning, architecture, workplace design, and lighting standards may all need reconsideration.

Seheult introduces a new term: photometabolism—solar-driven, non-photosynthetic modulation of core metabolic processes.

It’s a concept that positions sunlight not as a passive environmental factor, but as an active participant in the biochemistry of life itself.

I believe that this hypothesis if true has major implications for the built environment and how we live and the type of light that we require to live, and I believe it’s one of the major reasons why we need to be treating our patients outside.

Sources

• Jeffery et al. (2025) – Longer wavelengths in sunlight penetrating human tissue
• Ma et al. (2018) – Infrared perturbation of charge separation and recombination
• Sanderson et al. (2018) – Inhibitory modulation of cytochrome c oxidase with near-infrared wavelengths
• Dai et al. (2026) – Infrared stimulation of mitochondrial metabolism in deep-sea yeast
• Hayashi et al. (2010) – Water-mediated electron transfer in iron-sulfur bridges
• Marcus and Sutin (1985) – Electron transfer reactions in chemistry

When researchers blocked cytochrome c oxidase (complex IV in mitochondria), near-infrared-stimulated growth dropped by 44%—suggesting the effect operates directly on mitochondrial machinery.

Cold Temperatures, Warm Light

Even more remarkable: infrared light allowed yeast to grow at cooler temperatures where dark controls remained dormant.

At 20°C, yeast exposed to 880-nanometer light grew vigorously while dark controls showed minimal activity. The effective activation energy dropped from 12 kilocalories per mole to just 2 kilocalories per mole.

Infrared light was making up for the cold temperatures by supplying vibrational activation rather than thermal activation.

Proteomics revealed the most upregulated protein after infrared exposure was a mitochondrial ribosomal protein (MRPs8), increased 6.7-fold.

Why Broadband Sunlight May Beat Monochromatic LEDs

Clinical studies using single-wavelength infrared devices have shown benefits—from reducing ICU length of stay to improving muscle strength in COVID-19 patients.

But Seheult’s hypothesis suggests broadband infrared from the sun may be even more effective.

“Sunlight contains a broad spectrum of wavelengths that can interact with many different vibrational modes and electron transfer steps,” he explains, “rather than targeting only one narrow pathway.”

Research from Jeffery’s lab supports this. When comparing monochromatic 850-nanometer light to a 60-watt incandescent bulb (which emits broad-spectrum infrared), the incandescent bulb produced greater improvements in color blindness.

• Monochromatic 850 nm: 9% improvement (head and body), 5% (body only)
• 60W incandescent bulb: 28% improvement, sustained for weeks

The research here aligns with the hypothesis, though direct mechanistic proof in human mitochondria remains to be demonstrated.

The Modern Indoor Environment: A Metabolic Desert?

LED bulbs emit virtually no infrared radiation. Low-emissivity (Low-E) glass windows, designed to improve energy efficiency, block infrared wavelengths.

Seheult measured infrared exposure in his own dining room with windows open: 0.8 watts per square meter.

Step outside under a shade tree with grass reflecting sunlight? 41.9 watts per square meter—more than 50 times higher.

We have set up a situation where outdoors we’re getting plenty of infrared light, versus being indoors where we have Low-E glass blocking it and LED bulbs producing none.

This raises profound questions about whether chronic infrared deficiency could contribute to the rising burden of metabolic diseases, especially among populations spending most of their time indoors.

Seasonal Mortality Patterns Point to Sunlight’s Role

Death rates from heart disease, cancer, stroke, Alzheimer’s, diabetes, and respiratory illness all peak one to three weeks after the shortest day of the year and bottom out after the longest day.

This pattern holds across both infectious and non-infectious causes. The seasonal variation in heart disease deaths alone exceeds total influenza deaths during flu season.

Australia shows the same pattern, but shifted six months—deaths peak in July, their winter. Singapore, 80 miles from the equator with year-round sun, shows no seasonal mortality pattern.

Multiple studies have linked mortality rates to latitude, independent of vitamin D levels, suggesting sunlight itself—particularly its infrared component—plays a direct metabolic role.

Hospitals Are Bringing Patients Outside

Armed with mounting evidence, hospitals worldwide are redesigning care spaces to maximize sunlight exposure.

A $1.5 billion hospital in Footscray, Australia, built ICU beds with direct outdoor access. King’s College Hospital in London invested £2 million to transform its rooftop into a critical care garden where up to six ICU patients can receive treatment surrounded by greenery and natural light.

St. George’s Hospital in London followed suit, creating a neurointensive care rooftop unit. Queen Camilla visited the facility in 2026 to recognize the innovation.

Randomized controlled trials using infrared vests delivering roughly 20–30 watts per square meter (comparable to sitting under a tree) showed 30% reductions in ICU length of stay and improved muscle strength in critically ill COVID-19 patients.

Metabolic Scaling Matches Solar Power Scaling

One of the paper’s most intriguing observations: metabolic rate scales with body mass to the 3/4 power across species from flies to elephants.

Solar power intercepted by an organism also scales to the 3/4 power of mass—nearly identical.

This doesn’t prove causation, but it suggests sunlight could be a universal regulator of metabolic activity across the biosphere, with mitochondria in all organisms tuned to respond to the same infrared wavelengths present in Earth’s solar photon field.

What Makes This Hypothesis Different

Earlier theories proposed infrared light works by activating a photoreceptor in cytochrome c oxidase (complex IV) or by reducing water viscosity around ATP synthase motors.

Seheult’s team doesn’t reject these mechanisms—but argues they’re incomplete.

The Marcus framework explains phenomena earlier models couldn’t: why some infrared wavelengths inhibit rather than enhance mitochondrial activity, why broadband light outperforms monochromatic sources, and why effects persist across vastly different organisms.

The paper is the first to integrate four separate literature streams:

• Mitochondrial electron transfer follows Marcus physics
• Red and near-infrared light alter mitochondrial function
• Water and protein structures affect electron transfer kinetics
• Infrared radiation changes molecular electron transfer rates

“The novelty lies in the mechanistic integration,” Seheult emphasizes, “not in any single component.”

What Comes Next

The hypothesis is testable. Future experiments could measure how different infrared wavelengths alter specific Marcus crossing configurations in isolated mitochondrial complexes, or track real-time changes in reorganization energy using advanced spectroscopy.

If validated, the implications extend far beyond biology. Urban planning, architecture, workplace design, and lighting standards may all need reconsideration.

Seheult introduces a new term: photometabolism—solar-driven, non-photosynthetic modulation of core metabolic processes.

It’s a concept that positions sunlight not as a passive environmental factor, but as an active participant in the biochemistry of life itself.

I believe that this hypothesis if true has major implications for the built environment and how we live and the type of light that we require to live, and I believe it’s one of the major reasons why we need to be treating our patients outside.

Sources

• Jeffery et al. (2025) – Longer wavelengths in sunlight penetrating human tissue
• Ma et al. (2018) – Infrared perturbation of charge separation and recombination
• Sanderson et al. (2018) – Inhibitory modulation of cytochrome c oxidase with near-infrared wavelengths
• Dai et al. (2026) – Infrared stimulation of mitochondrial metabolism in deep-sea yeast
• Hayashi et al. (2010) – Water-mediated electron transfer in iron-sulfur bridges
• Marcus and Sutin (1985) – Electron transfer reactions in chemistry

When researchers blocked cytochrome c oxidase (complex IV in mitochondria), near-infrared-stimulated growth dropped by 44%—suggesting the effect operates directly on mitochondrial machinery.

Cold Temperatures, Warm Light

Even more remarkable: infrared light allowed yeast to grow at cooler temperatures where dark controls remained dormant.

At 20°C, yeast exposed to 880-nanometer light grew vigorously while dark controls showed minimal activity. The effective activation energy dropped from 12 kilocalories per mole to just 2 kilocalories per mole.

Infrared light was making up for the cold temperatures by supplying vibrational activation rather than thermal activation.

Proteomics revealed the most upregulated protein after infrared exposure was a mitochondrial ribosomal protein (MRPs8), increased 6.7-fold.

Why Broadband Sunlight May Beat Monochromatic LEDs

Clinical studies using single-wavelength infrared devices have shown benefits—from reducing ICU length of stay to improving muscle strength in COVID-19 patients.

But Seheult’s hypothesis suggests broadband infrared from the sun may be even more effective.

“Sunlight contains a broad spectrum of wavelengths that can interact with many different vibrational modes and electron transfer steps,” he explains, “rather than targeting only one narrow pathway.”

Research from Jeffery’s lab supports this. When comparing monochromatic 850-nanometer light to a 60-watt incandescent bulb (which emits broad-spectrum infrared), the incandescent bulb produced greater improvements in color blindness.

• Monochromatic 850 nm: 9% improvement (head and body), 5% (body only)
• 60W incandescent bulb: 28% improvement, sustained for weeks

The research here aligns with the hypothesis, though direct mechanistic proof in human mitochondria remains to be demonstrated.

The Modern Indoor Environment: A Metabolic Desert?

LED bulbs emit virtually no infrared radiation. Low-emissivity (Low-E) glass windows, designed to improve energy efficiency, block infrared wavelengths.

Seheult measured infrared exposure in his own dining room with windows open: 0.8 watts per square meter.

Step outside under a shade tree with grass reflecting sunlight? 41.9 watts per square meter—more than 50 times higher.

We have set up a situation where outdoors we’re getting plenty of infrared light, versus being indoors where we have Low-E glass blocking it and LED bulbs producing none.

This raises profound questions about whether chronic infrared deficiency could contribute to the rising burden of metabolic diseases, especially among populations spending most of their time indoors.

Seasonal Mortality Patterns Point to Sunlight’s Role

Death rates from heart disease, cancer, stroke, Alzheimer’s, diabetes, and respiratory illness all peak one to three weeks after the shortest day of the year and bottom out after the longest day.

This pattern holds across both infectious and non-infectious causes. The seasonal variation in heart disease deaths alone exceeds total influenza deaths during flu season.

Australia shows the same pattern, but shifted six months—deaths peak in July, their winter. Singapore, 80 miles from the equator with year-round sun, shows no seasonal mortality pattern.

Multiple studies have linked mortality rates to latitude, independent of vitamin D levels, suggesting sunlight itself—particularly its infrared component—plays a direct metabolic role.

Hospitals Are Bringing Patients Outside

Armed with mounting evidence, hospitals worldwide are redesigning care spaces to maximize sunlight exposure.

A $1.5 billion hospital in Footscray, Australia, built ICU beds with direct outdoor access. King’s College Hospital in London invested £2 million to transform its rooftop into a critical care garden where up to six ICU patients can receive treatment surrounded by greenery and natural light.

St. George’s Hospital in London followed suit, creating a neurointensive care rooftop unit. Queen Camilla visited the facility in 2026 to recognize the innovation.

Randomized controlled trials using infrared vests delivering roughly 20–30 watts per square meter (comparable to sitting under a tree) showed 30% reductions in ICU length of stay and improved muscle strength in critically ill COVID-19 patients.

Metabolic Scaling Matches Solar Power Scaling

One of the paper’s most intriguing observations: metabolic rate scales with body mass to the 3/4 power across species from flies to elephants.

Solar power intercepted by an organism also scales to the 3/4 power of mass—nearly identical.

This doesn’t prove causation, but it suggests sunlight could be a universal regulator of metabolic activity across the biosphere, with mitochondria in all organisms tuned to respond to the same infrared wavelengths present in Earth’s solar photon field.

What Makes This Hypothesis Different

Earlier theories proposed infrared light works by activating a photoreceptor in cytochrome c oxidase (complex IV) or by reducing water viscosity around ATP synthase motors.

Seheult’s team doesn’t reject these mechanisms—but argues they’re incomplete.

The Marcus framework explains phenomena earlier models couldn’t: why some infrared wavelengths inhibit rather than enhance mitochondrial activity, why broadband light outperforms monochromatic sources, and why effects persist across vastly different organisms.

The paper is the first to integrate four separate literature streams:

• Mitochondrial electron transfer follows Marcus physics
• Red and near-infrared light alter mitochondrial function
• Water and protein structures affect electron transfer kinetics
• Infrared radiation changes molecular electron transfer rates

“The novelty lies in the mechanistic integration,” Seheult emphasizes, “not in any single component.”

What Comes Next

The hypothesis is testable. Future experiments could measure how different infrared wavelengths alter specific Marcus crossing configurations in isolated mitochondrial complexes, or track real-time changes in reorganization energy using advanced spectroscopy.

If validated, the implications extend far beyond biology. Urban planning, architecture, workplace design, and lighting standards may all need reconsideration.

Seheult introduces a new term: photometabolism—solar-driven, non-photosynthetic modulation of core metabolic processes.

It’s a concept that positions sunlight not as a passive environmental factor, but as an active participant in the biochemistry of life itself.

I believe that this hypothesis if true has major implications for the built environment and how we live and the type of light that we require to live, and I believe it’s one of the major reasons why we need to be treating our patients outside.

Sources

• Jeffery et al. (2025) – Longer wavelengths in sunlight penetrating human tissue
• Ma et al. (2018) – Infrared perturbation of charge separation and recombination
• Sanderson et al. (2018) – Inhibitory modulation of cytochrome c oxidase with near-infrared wavelengths
• Dai et al. (2026) – Infrared stimulation of mitochondrial metabolism in deep-sea yeast
• Hayashi et al. (2010) – Water-mediated electron transfer in iron-sulfur bridges
• Marcus and Sutin (1985) – Electron transfer reactions in chemistry

Infrared light outperformed glucose. Adding glucose increased biomass by only 1.3-fold (not statistically significant), while 880-nanometer infrared light produced a threefold increase.

When researchers blocked cytochrome c oxidase (complex IV in mitochondria), near-infrared-stimulated growth dropped by 44%—suggesting the effect operates directly on mitochondrial machinery.

Cold Temperatures, Warm Light

Even more remarkable: infrared light allowed yeast to grow at cooler temperatures where dark controls remained dormant.

At 20°C, yeast exposed to 880-nanometer light grew vigorously while dark controls showed minimal activity. The effective activation energy dropped from 12 kilocalories per mole to just 2 kilocalories per mole.

Infrared light was making up for the cold temperatures by supplying vibrational activation rather than thermal activation.

Proteomics revealed the most upregulated protein after infrared exposure was a mitochondrial ribosomal protein (MRPs8), increased 6.7-fold.

Why Broadband Sunlight May Beat Monochromatic LEDs

Clinical studies using single-wavelength infrared devices have shown benefits—from reducing ICU length of stay to improving muscle strength in COVID-19 patients.

But Seheult’s hypothesis suggests broadband infrared from the sun may be even more effective.

“Sunlight contains a broad spectrum of wavelengths that can interact with many different vibrational modes and electron transfer steps,” he explains, “rather than targeting only one narrow pathway.”

Research from Jeffery’s lab supports this. When comparing monochromatic 850-nanometer light to a 60-watt incandescent bulb (which emits broad-spectrum infrared), the incandescent bulb produced greater improvements in color blindness.

• Monochromatic 850 nm: 9% improvement (head and body), 5% (body only)
• 60W incandescent bulb: 28% improvement, sustained for weeks

The research here aligns with the hypothesis, though direct mechanistic proof in human mitochondria remains to be demonstrated.

The Modern Indoor Environment: A Metabolic Desert?

LED bulbs emit virtually no infrared radiation. Low-emissivity (Low-E) glass windows, designed to improve energy efficiency, block infrared wavelengths.

Seheult measured infrared exposure in his own dining room with windows open: 0.8 watts per square meter.

Step outside under a shade tree with grass reflecting sunlight? 41.9 watts per square meter—more than 50 times higher.

We have set up a situation where outdoors we’re getting plenty of infrared light, versus being indoors where we have Low-E glass blocking it and LED bulbs producing none.

This raises profound questions about whether chronic infrared deficiency could contribute to the rising burden of metabolic diseases, especially among populations spending most of their time indoors.

Seasonal Mortality Patterns Point to Sunlight’s Role

Death rates from heart disease, cancer, stroke, Alzheimer’s, diabetes, and respiratory illness all peak one to three weeks after the shortest day of the year and bottom out after the longest day.

This pattern holds across both infectious and non-infectious causes. The seasonal variation in heart disease deaths alone exceeds total influenza deaths during flu season.

Australia shows the same pattern, but shifted six months—deaths peak in July, their winter. Singapore, 80 miles from the equator with year-round sun, shows no seasonal mortality pattern.

Multiple studies have linked mortality rates to latitude, independent of vitamin D levels, suggesting sunlight itself—particularly its infrared component—plays a direct metabolic role.

Hospitals Are Bringing Patients Outside

Armed with mounting evidence, hospitals worldwide are redesigning care spaces to maximize sunlight exposure.

A $1.5 billion hospital in Footscray, Australia, built ICU beds with direct outdoor access. King’s College Hospital in London invested £2 million to transform its rooftop into a critical care garden where up to six ICU patients can receive treatment surrounded by greenery and natural light.

St. George’s Hospital in London followed suit, creating a neurointensive care rooftop unit. Queen Camilla visited the facility in 2026 to recognize the innovation.

Randomized controlled trials using infrared vests delivering roughly 20–30 watts per square meter (comparable to sitting under a tree) showed 30% reductions in ICU length of stay and improved muscle strength in critically ill COVID-19 patients.

Metabolic Scaling Matches Solar Power Scaling

One of the paper’s most intriguing observations: metabolic rate scales with body mass to the 3/4 power across species from flies to elephants.

Solar power intercepted by an organism also scales to the 3/4 power of mass—nearly identical.

This doesn’t prove causation, but it suggests sunlight could be a universal regulator of metabolic activity across the biosphere, with mitochondria in all organisms tuned to respond to the same infrared wavelengths present in Earth’s solar photon field.

What Makes This Hypothesis Different

Earlier theories proposed infrared light works by activating a photoreceptor in cytochrome c oxidase (complex IV) or by reducing water viscosity around ATP synthase motors.

Seheult’s team doesn’t reject these mechanisms—but argues they’re incomplete.

The Marcus framework explains phenomena earlier models couldn’t: why some infrared wavelengths inhibit rather than enhance mitochondrial activity, why broadband light outperforms monochromatic sources, and why effects persist across vastly different organisms.

The paper is the first to integrate four separate literature streams:

• Mitochondrial electron transfer follows Marcus physics
• Red and near-infrared light alter mitochondrial function
• Water and protein structures affect electron transfer kinetics
• Infrared radiation changes molecular electron transfer rates

“The novelty lies in the mechanistic integration,” Seheult emphasizes, “not in any single component.”

What Comes Next

The hypothesis is testable. Future experiments could measure how different infrared wavelengths alter specific Marcus crossing configurations in isolated mitochondrial complexes, or track real-time changes in reorganization energy using advanced spectroscopy.

If validated, the implications extend far beyond biology. Urban planning, architecture, workplace design, and lighting standards may all need reconsideration.

Seheult introduces a new term: photometabolism—solar-driven, non-photosynthetic modulation of core metabolic processes.

It’s a concept that positions sunlight not as a passive environmental factor, but as an active participant in the biochemistry of life itself.

I believe that this hypothesis if true has major implications for the built environment and how we live and the type of light that we require to live, and I believe it’s one of the major reasons why we need to be treating our patients outside.

Sources

• Jeffery et al. (2025) – Longer wavelengths in sunlight penetrating human tissue
• Ma et al. (2018) – Infrared perturbation of charge separation and recombination
• Sanderson et al. (2018) – Inhibitory modulation of cytochrome c oxidase with near-infrared wavelengths
• Dai et al. (2026) – Infrared stimulation of mitochondrial metabolism in deep-sea yeast
• Hayashi et al. (2010) – Water-mediated electron transfer in iron-sulfur bridges
• Marcus and Sutin (1985) – Electron transfer reactions in chemistry

Infrared light outperformed glucose. Adding glucose increased biomass by only 1.3-fold (not statistically significant), while 880-nanometer infrared light produced a threefold increase.

When researchers blocked cytochrome c oxidase (complex IV in mitochondria), near-infrared-stimulated growth dropped by 44%—suggesting the effect operates directly on mitochondrial machinery.

Cold Temperatures, Warm Light

Even more remarkable: infrared light allowed yeast to grow at cooler temperatures where dark controls remained dormant.

At 20°C, yeast exposed to 880-nanometer light grew vigorously while dark controls showed minimal activity. The effective activation energy dropped from 12 kilocalories per mole to just 2 kilocalories per mole.

Infrared light was making up for the cold temperatures by supplying vibrational activation rather than thermal activation.

Proteomics revealed the most upregulated protein after infrared exposure was a mitochondrial ribosomal protein (MRPs8), increased 6.7-fold.

Why Broadband Sunlight May Beat Monochromatic LEDs

Clinical studies using single-wavelength infrared devices have shown benefits—from reducing ICU length of stay to improving muscle strength in COVID-19 patients.

But Seheult’s hypothesis suggests broadband infrared from the sun may be even more effective.

“Sunlight contains a broad spectrum of wavelengths that can interact with many different vibrational modes and electron transfer steps,” he explains, “rather than targeting only one narrow pathway.”

Research from Jeffery’s lab supports this. When comparing monochromatic 850-nanometer light to a 60-watt incandescent bulb (which emits broad-spectrum infrared), the incandescent bulb produced greater improvements in color blindness.

• Monochromatic 850 nm: 9% improvement (head and body), 5% (body only)
• 60W incandescent bulb: 28% improvement, sustained for weeks

The research here aligns with the hypothesis, though direct mechanistic proof in human mitochondria remains to be demonstrated.

The Modern Indoor Environment: A Metabolic Desert?

LED bulbs emit virtually no infrared radiation. Low-emissivity (Low-E) glass windows, designed to improve energy efficiency, block infrared wavelengths.

Seheult measured infrared exposure in his own dining room with windows open: 0.8 watts per square meter.

Step outside under a shade tree with grass reflecting sunlight? 41.9 watts per square meter—more than 50 times higher.

We have set up a situation where outdoors we’re getting plenty of infrared light, versus being indoors where we have Low-E glass blocking it and LED bulbs producing none.

This raises profound questions about whether chronic infrared deficiency could contribute to the rising burden of metabolic diseases, especially among populations spending most of their time indoors.

Seasonal Mortality Patterns Point to Sunlight’s Role

Death rates from heart disease, cancer, stroke, Alzheimer’s, diabetes, and respiratory illness all peak one to three weeks after the shortest day of the year and bottom out after the longest day.

This pattern holds across both infectious and non-infectious causes. The seasonal variation in heart disease deaths alone exceeds total influenza deaths during flu season.

Australia shows the same pattern, but shifted six months—deaths peak in July, their winter. Singapore, 80 miles from the equator with year-round sun, shows no seasonal mortality pattern.

Multiple studies have linked mortality rates to latitude, independent of vitamin D levels, suggesting sunlight itself—particularly its infrared component—plays a direct metabolic role.

Hospitals Are Bringing Patients Outside

Armed with mounting evidence, hospitals worldwide are redesigning care spaces to maximize sunlight exposure.

A $1.5 billion hospital in Footscray, Australia, built ICU beds with direct outdoor access. King’s College Hospital in London invested £2 million to transform its rooftop into a critical care garden where up to six ICU patients can receive treatment surrounded by greenery and natural light.

St. George’s Hospital in London followed suit, creating a neurointensive care rooftop unit. Queen Camilla visited the facility in 2026 to recognize the innovation.

Randomized controlled trials using infrared vests delivering roughly 20–30 watts per square meter (comparable to sitting under a tree) showed 30% reductions in ICU length of stay and improved muscle strength in critically ill COVID-19 patients.

Metabolic Scaling Matches Solar Power Scaling

One of the paper’s most intriguing observations: metabolic rate scales with body mass to the 3/4 power across species from flies to elephants.

Solar power intercepted by an organism also scales to the 3/4 power of mass—nearly identical.

This doesn’t prove causation, but it suggests sunlight could be a universal regulator of metabolic activity across the biosphere, with mitochondria in all organisms tuned to respond to the same infrared wavelengths present in Earth’s solar photon field.

What Makes This Hypothesis Different

Earlier theories proposed infrared light works by activating a photoreceptor in cytochrome c oxidase (complex IV) or by reducing water viscosity around ATP synthase motors.

Seheult’s team doesn’t reject these mechanisms—but argues they’re incomplete.

The Marcus framework explains phenomena earlier models couldn’t: why some infrared wavelengths inhibit rather than enhance mitochondrial activity, why broadband light outperforms monochromatic sources, and why effects persist across vastly different organisms.

The paper is the first to integrate four separate literature streams:

• Mitochondrial electron transfer follows Marcus physics
• Red and near-infrared light alter mitochondrial function
• Water and protein structures affect electron transfer kinetics
• Infrared radiation changes molecular electron transfer rates

“The novelty lies in the mechanistic integration,” Seheult emphasizes, “not in any single component.”

What Comes Next

The hypothesis is testable. Future experiments could measure how different infrared wavelengths alter specific Marcus crossing configurations in isolated mitochondrial complexes, or track real-time changes in reorganization energy using advanced spectroscopy.

If validated, the implications extend far beyond biology. Urban planning, architecture, workplace design, and lighting standards may all need reconsideration.

Seheult introduces a new term: photometabolism—solar-driven, non-photosynthetic modulation of core metabolic processes.

It’s a concept that positions sunlight not as a passive environmental factor, but as an active participant in the biochemistry of life itself.

I believe that this hypothesis if true has major implications for the built environment and how we live and the type of light that we require to live, and I believe it’s one of the major reasons why we need to be treating our patients outside.

Sources

• Jeffery et al. (2025) – Longer wavelengths in sunlight penetrating human tissue
• Ma et al. (2018) – Infrared perturbation of charge separation and recombination
• Sanderson et al. (2018) – Inhibitory modulation of cytochrome c oxidase with near-infrared wavelengths
• Dai et al. (2026) – Infrared stimulation of mitochondrial metabolism in deep-sea yeast
• Hayashi et al. (2010) – Water-mediated electron transfer in iron-sulfur bridges
• Marcus and Sutin (1985) – Electron transfer reactions in chemistry

When researchers exposed these yeast cultures to near-infrared light (810–1050 nm) in temperature-controlled conditions, growth increased dramatically compared to dark controls—even though the yeast cannot photosynthesize.

Infrared light outperformed glucose. Adding glucose increased biomass by only 1.3-fold (not statistically significant), while 880-nanometer infrared light produced a threefold increase.

When researchers blocked cytochrome c oxidase (complex IV in mitochondria), near-infrared-stimulated growth dropped by 44%—suggesting the effect operates directly on mitochondrial machinery.

Cold Temperatures, Warm Light

Even more remarkable: infrared light allowed yeast to grow at cooler temperatures where dark controls remained dormant.

At 20°C, yeast exposed to 880-nanometer light grew vigorously while dark controls showed minimal activity. The effective activation energy dropped from 12 kilocalories per mole to just 2 kilocalories per mole.

Infrared light was making up for the cold temperatures by supplying vibrational activation rather than thermal activation.

Proteomics revealed the most upregulated protein after infrared exposure was a mitochondrial ribosomal protein (MRPs8), increased 6.7-fold.

Why Broadband Sunlight May Beat Monochromatic LEDs

Clinical studies using single-wavelength infrared devices have shown benefits—from reducing ICU length of stay to improving muscle strength in COVID-19 patients.

But Seheult’s hypothesis suggests broadband infrared from the sun may be even more effective.

“Sunlight contains a broad spectrum of wavelengths that can interact with many different vibrational modes and electron transfer steps,” he explains, “rather than targeting only one narrow pathway.”

Research from Jeffery’s lab supports this. When comparing monochromatic 850-nanometer light to a 60-watt incandescent bulb (which emits broad-spectrum infrared), the incandescent bulb produced greater improvements in color blindness.

• Monochromatic 850 nm: 9% improvement (head and body), 5% (body only)
• 60W incandescent bulb: 28% improvement, sustained for weeks

The research here aligns with the hypothesis, though direct mechanistic proof in human mitochondria remains to be demonstrated.

The Modern Indoor Environment: A Metabolic Desert?

LED bulbs emit virtually no infrared radiation. Low-emissivity (Low-E) glass windows, designed to improve energy efficiency, block infrared wavelengths.

Seheult measured infrared exposure in his own dining room with windows open: 0.8 watts per square meter.

Step outside under a shade tree with grass reflecting sunlight? 41.9 watts per square meter—more than 50 times higher.

We have set up a situation where outdoors we’re getting plenty of infrared light, versus being indoors where we have Low-E glass blocking it and LED bulbs producing none.

This raises profound questions about whether chronic infrared deficiency could contribute to the rising burden of metabolic diseases, especially among populations spending most of their time indoors.

Seasonal Mortality Patterns Point to Sunlight’s Role

Death rates from heart disease, cancer, stroke, Alzheimer’s, diabetes, and respiratory illness all peak one to three weeks after the shortest day of the year and bottom out after the longest day.

This pattern holds across both infectious and non-infectious causes. The seasonal variation in heart disease deaths alone exceeds total influenza deaths during flu season.

Australia shows the same pattern, but shifted six months—deaths peak in July, their winter. Singapore, 80 miles from the equator with year-round sun, shows no seasonal mortality pattern.

Multiple studies have linked mortality rates to latitude, independent of vitamin D levels, suggesting sunlight itself—particularly its infrared component—plays a direct metabolic role.

Hospitals Are Bringing Patients Outside

Armed with mounting evidence, hospitals worldwide are redesigning care spaces to maximize sunlight exposure.

A $1.5 billion hospital in Footscray, Australia, built ICU beds with direct outdoor access. King’s College Hospital in London invested £2 million to transform its rooftop into a critical care garden where up to six ICU patients can receive treatment surrounded by greenery and natural light.

St. George’s Hospital in London followed suit, creating a neurointensive care rooftop unit. Queen Camilla visited the facility in 2026 to recognize the innovation.

Randomized controlled trials using infrared vests delivering roughly 20–30 watts per square meter (comparable to sitting under a tree) showed 30% reductions in ICU length of stay and improved muscle strength in critically ill COVID-19 patients.

Metabolic Scaling Matches Solar Power Scaling

One of the paper’s most intriguing observations: metabolic rate scales with body mass to the 3/4 power across species from flies to elephants.

Solar power intercepted by an organism also scales to the 3/4 power of mass—nearly identical.

This doesn’t prove causation, but it suggests sunlight could be a universal regulator of metabolic activity across the biosphere, with mitochondria in all organisms tuned to respond to the same infrared wavelengths present in Earth’s solar photon field.

What Makes This Hypothesis Different

Earlier theories proposed infrared light works by activating a photoreceptor in cytochrome c oxidase (complex IV) or by reducing water viscosity around ATP synthase motors.

Seheult’s team doesn’t reject these mechanisms—but argues they’re incomplete.

The Marcus framework explains phenomena earlier models couldn’t: why some infrared wavelengths inhibit rather than enhance mitochondrial activity, why broadband light outperforms monochromatic sources, and why effects persist across vastly different organisms.

The paper is the first to integrate four separate literature streams:

• Mitochondrial electron transfer follows Marcus physics
• Red and near-infrared light alter mitochondrial function
• Water and protein structures affect electron transfer kinetics
• Infrared radiation changes molecular electron transfer rates

“The novelty lies in the mechanistic integration,” Seheult emphasizes, “not in any single component.”

What Comes Next

The hypothesis is testable. Future experiments could measure how different infrared wavelengths alter specific Marcus crossing configurations in isolated mitochondrial complexes, or track real-time changes in reorganization energy using advanced spectroscopy.

If validated, the implications extend far beyond biology. Urban planning, architecture, workplace design, and lighting standards may all need reconsideration.

Seheult introduces a new term: photometabolism—solar-driven, non-photosynthetic modulation of core metabolic processes.

It’s a concept that positions sunlight not as a passive environmental factor, but as an active participant in the biochemistry of life itself.

I believe that this hypothesis if true has major implications for the built environment and how we live and the type of light that we require to live, and I believe it’s one of the major reasons why we need to be treating our patients outside.

Sources

• Jeffery et al. (2025) – Longer wavelengths in sunlight penetrating human tissue
• Ma et al. (2018) – Infrared perturbation of charge separation and recombination
• Sanderson et al. (2018) – Inhibitory modulation of cytochrome c oxidase with near-infrared wavelengths
• Dai et al. (2026) – Infrared stimulation of mitochondrial metabolism in deep-sea yeast
• Hayashi et al. (2010) – Water-mediated electron transfer in iron-sulfur bridges
• Marcus and Sutin (1985) – Electron transfer reactions in chemistry

When researchers exposed these yeast cultures to near-infrared light (810–1050 nm) in temperature-controlled conditions, growth increased dramatically compared to dark controls—even though the yeast cannot photosynthesize.

Infrared light outperformed glucose. Adding glucose increased biomass by only 1.3-fold (not statistically significant), while 880-nanometer infrared light produced a threefold increase.

When researchers blocked cytochrome c oxidase (complex IV in mitochondria), near-infrared-stimulated growth dropped by 44%—suggesting the effect operates directly on mitochondrial machinery.

Cold Temperatures, Warm Light

Even more remarkable: infrared light allowed yeast to grow at cooler temperatures where dark controls remained dormant.

At 20°C, yeast exposed to 880-nanometer light grew vigorously while dark controls showed minimal activity. The effective activation energy dropped from 12 kilocalories per mole to just 2 kilocalories per mole.

Infrared light was making up for the cold temperatures by supplying vibrational activation rather than thermal activation.

Proteomics revealed the most upregulated protein after infrared exposure was a mitochondrial ribosomal protein (MRPs8), increased 6.7-fold.

Why Broadband Sunlight May Beat Monochromatic LEDs

Clinical studies using single-wavelength infrared devices have shown benefits—from reducing ICU length of stay to improving muscle strength in COVID-19 patients.

But Seheult’s hypothesis suggests broadband infrared from the sun may be even more effective.

“Sunlight contains a broad spectrum of wavelengths that can interact with many different vibrational modes and electron transfer steps,” he explains, “rather than targeting only one narrow pathway.”

Research from Jeffery’s lab supports this. When comparing monochromatic 850-nanometer light to a 60-watt incandescent bulb (which emits broad-spectrum infrared), the incandescent bulb produced greater improvements in color blindness.

• Monochromatic 850 nm: 9% improvement (head and body), 5% (body only)
• 60W incandescent bulb: 28% improvement, sustained for weeks

The research here aligns with the hypothesis, though direct mechanistic proof in human mitochondria remains to be demonstrated.

The Modern Indoor Environment: A Metabolic Desert?

LED bulbs emit virtually no infrared radiation. Low-emissivity (Low-E) glass windows, designed to improve energy efficiency, block infrared wavelengths.

Seheult measured infrared exposure in his own dining room with windows open: 0.8 watts per square meter.

Step outside under a shade tree with grass reflecting sunlight? 41.9 watts per square meter—more than 50 times higher.

We have set up a situation where outdoors we’re getting plenty of infrared light, versus being indoors where we have Low-E glass blocking it and LED bulbs producing none.

This raises profound questions about whether chronic infrared deficiency could contribute to the rising burden of metabolic diseases, especially among populations spending most of their time indoors.

Seasonal Mortality Patterns Point to Sunlight’s Role

Death rates from heart disease, cancer, stroke, Alzheimer’s, diabetes, and respiratory illness all peak one to three weeks after the shortest day of the year and bottom out after the longest day.

This pattern holds across both infectious and non-infectious causes. The seasonal variation in heart disease deaths alone exceeds total influenza deaths during flu season.

Australia shows the same pattern, but shifted six months—deaths peak in July, their winter. Singapore, 80 miles from the equator with year-round sun, shows no seasonal mortality pattern.

Multiple studies have linked mortality rates to latitude, independent of vitamin D levels, suggesting sunlight itself—particularly its infrared component—plays a direct metabolic role.

Hospitals Are Bringing Patients Outside

Armed with mounting evidence, hospitals worldwide are redesigning care spaces to maximize sunlight exposure.

A $1.5 billion hospital in Footscray, Australia, built ICU beds with direct outdoor access. King’s College Hospital in London invested £2 million to transform its rooftop into a critical care garden where up to six ICU patients can receive treatment surrounded by greenery and natural light.

St. George’s Hospital in London followed suit, creating a neurointensive care rooftop unit. Queen Camilla visited the facility in 2026 to recognize the innovation.

Randomized controlled trials using infrared vests delivering roughly 20–30 watts per square meter (comparable to sitting under a tree) showed 30% reductions in ICU length of stay and improved muscle strength in critically ill COVID-19 patients.

Metabolic Scaling Matches Solar Power Scaling

One of the paper’s most intriguing observations: metabolic rate scales with body mass to the 3/4 power across species from flies to elephants.

Solar power intercepted by an organism also scales to the 3/4 power of mass—nearly identical.

This doesn’t prove causation, but it suggests sunlight could be a universal regulator of metabolic activity across the biosphere, with mitochondria in all organisms tuned to respond to the same infrared wavelengths present in Earth’s solar photon field.

What Makes This Hypothesis Different

Earlier theories proposed infrared light works by activating a photoreceptor in cytochrome c oxidase (complex IV) or by reducing water viscosity around ATP synthase motors.

Seheult’s team doesn’t reject these mechanisms—but argues they’re incomplete.

The Marcus framework explains phenomena earlier models couldn’t: why some infrared wavelengths inhibit rather than enhance mitochondrial activity, why broadband light outperforms monochromatic sources, and why effects persist across vastly different organisms.

The paper is the first to integrate four separate literature streams:

• Mitochondrial electron transfer follows Marcus physics
• Red and near-infrared light alter mitochondrial function
• Water and protein structures affect electron transfer kinetics
• Infrared radiation changes molecular electron transfer rates

“The novelty lies in the mechanistic integration,” Seheult emphasizes, “not in any single component.”

What Comes Next

The hypothesis is testable. Future experiments could measure how different infrared wavelengths alter specific Marcus crossing configurations in isolated mitochondrial complexes, or track real-time changes in reorganization energy using advanced spectroscopy.

If validated, the implications extend far beyond biology. Urban planning, architecture, workplace design, and lighting standards may all need reconsideration.

Seheult introduces a new term: photometabolism—solar-driven, non-photosynthetic modulation of core metabolic processes.

It’s a concept that positions sunlight not as a passive environmental factor, but as an active participant in the biochemistry of life itself.

I believe that this hypothesis if true has major implications for the built environment and how we live and the type of light that we require to live, and I believe it’s one of the major reasons why we need to be treating our patients outside.

Sources

• Jeffery et al. (2025) – Longer wavelengths in sunlight penetrating human tissue
• Ma et al. (2018) – Infrared perturbation of charge separation and recombination
• Sanderson et al. (2018) – Inhibitory modulation of cytochrome c oxidase with near-infrared wavelengths
• Dai et al. (2026) – Infrared stimulation of mitochondrial metabolism in deep-sea yeast
• Hayashi et al. (2010) – Water-mediated electron transfer in iron-sulfur bridges
• Marcus and Sutin (1985) – Electron transfer reactions in chemistry

A 2026 study by Dai and colleagues isolated yeast from sediments near a “black smoker” chimney in the central Indian Ocean, more than half a meter from superheated mineral plumes reaching 378°C.

When researchers exposed these yeast cultures to near-infrared light (810–1050 nm) in temperature-controlled conditions, growth increased dramatically compared to dark controls—even though the yeast cannot photosynthesize.

Infrared light outperformed glucose. Adding glucose increased biomass by only 1.3-fold (not statistically significant), while 880-nanometer infrared light produced a threefold increase.

When researchers blocked cytochrome c oxidase (complex IV in mitochondria), near-infrared-stimulated growth dropped by 44%—suggesting the effect operates directly on mitochondrial machinery.

Cold Temperatures, Warm Light

Even more remarkable: infrared light allowed yeast to grow at cooler temperatures where dark controls remained dormant.

At 20°C, yeast exposed to 880-nanometer light grew vigorously while dark controls showed minimal activity. The effective activation energy dropped from 12 kilocalories per mole to just 2 kilocalories per mole.

Infrared light was making up for the cold temperatures by supplying vibrational activation rather than thermal activation.

Proteomics revealed the most upregulated protein after infrared exposure was a mitochondrial ribosomal protein (MRPs8), increased 6.7-fold.

Why Broadband Sunlight May Beat Monochromatic LEDs

Clinical studies using single-wavelength infrared devices have shown benefits—from reducing ICU length of stay to improving muscle strength in COVID-19 patients.

But Seheult’s hypothesis suggests broadband infrared from the sun may be even more effective.

“Sunlight contains a broad spectrum of wavelengths that can interact with many different vibrational modes and electron transfer steps,” he explains, “rather than targeting only one narrow pathway.”

Research from Jeffery’s lab supports this. When comparing monochromatic 850-nanometer light to a 60-watt incandescent bulb (which emits broad-spectrum infrared), the incandescent bulb produced greater improvements in color blindness.

• Monochromatic 850 nm: 9% improvement (head and body), 5% (body only)
• 60W incandescent bulb: 28% improvement, sustained for weeks

The research here aligns with the hypothesis, though direct mechanistic proof in human mitochondria remains to be demonstrated.

The Modern Indoor Environment: A Metabolic Desert?

LED bulbs emit virtually no infrared radiation. Low-emissivity (Low-E) glass windows, designed to improve energy efficiency, block infrared wavelengths.

Seheult measured infrared exposure in his own dining room with windows open: 0.8 watts per square meter.

Step outside under a shade tree with grass reflecting sunlight? 41.9 watts per square meter—more than 50 times higher.

We have set up a situation where outdoors we’re getting plenty of infrared light, versus being indoors where we have Low-E glass blocking it and LED bulbs producing none.

This raises profound questions about whether chronic infrared deficiency could contribute to the rising burden of metabolic diseases, especially among populations spending most of their time indoors.

Seasonal Mortality Patterns Point to Sunlight’s Role

Death rates from heart disease, cancer, stroke, Alzheimer’s, diabetes, and respiratory illness all peak one to three weeks after the shortest day of the year and bottom out after the longest day.

This pattern holds across both infectious and non-infectious causes. The seasonal variation in heart disease deaths alone exceeds total influenza deaths during flu season.

Australia shows the same pattern, but shifted six months—deaths peak in July, their winter. Singapore, 80 miles from the equator with year-round sun, shows no seasonal mortality pattern.

Multiple studies have linked mortality rates to latitude, independent of vitamin D levels, suggesting sunlight itself—particularly its infrared component—plays a direct metabolic role.

Hospitals Are Bringing Patients Outside

Armed with mounting evidence, hospitals worldwide are redesigning care spaces to maximize sunlight exposure.

A $1.5 billion hospital in Footscray, Australia, built ICU beds with direct outdoor access. King’s College Hospital in London invested £2 million to transform its rooftop into a critical care garden where up to six ICU patients can receive treatment surrounded by greenery and natural light.

St. George’s Hospital in London followed suit, creating a neurointensive care rooftop unit. Queen Camilla visited the facility in 2026 to recognize the innovation.

Randomized controlled trials using infrared vests delivering roughly 20–30 watts per square meter (comparable to sitting under a tree) showed 30% reductions in ICU length of stay and improved muscle strength in critically ill COVID-19 patients.

Metabolic Scaling Matches Solar Power Scaling

One of the paper’s most intriguing observations: metabolic rate scales with body mass to the 3/4 power across species from flies to elephants.

Solar power intercepted by an organism also scales to the 3/4 power of mass—nearly identical.

This doesn’t prove causation, but it suggests sunlight could be a universal regulator of metabolic activity across the biosphere, with mitochondria in all organisms tuned to respond to the same infrared wavelengths present in Earth’s solar photon field.

What Makes This Hypothesis Different

Earlier theories proposed infrared light works by activating a photoreceptor in cytochrome c oxidase (complex IV) or by reducing water viscosity around ATP synthase motors.

Seheult’s team doesn’t reject these mechanisms—but argues they’re incomplete.

The Marcus framework explains phenomena earlier models couldn’t: why some infrared wavelengths inhibit rather than enhance mitochondrial activity, why broadband light outperforms monochromatic sources, and why effects persist across vastly different organisms.

The paper is the first to integrate four separate literature streams:

• Mitochondrial electron transfer follows Marcus physics
• Red and near-infrared light alter mitochondrial function
• Water and protein structures affect electron transfer kinetics
• Infrared radiation changes molecular electron transfer rates

“The novelty lies in the mechanistic integration,” Seheult emphasizes, “not in any single component.”

What Comes Next

The hypothesis is testable. Future experiments could measure how different infrared wavelengths alter specific Marcus crossing configurations in isolated mitochondrial complexes, or track real-time changes in reorganization energy using advanced spectroscopy.

If validated, the implications extend far beyond biology. Urban planning, architecture, workplace design, and lighting standards may all need reconsideration.

Seheult introduces a new term: photometabolism—solar-driven, non-photosynthetic modulation of core metabolic processes.

It’s a concept that positions sunlight not as a passive environmental factor, but as an active participant in the biochemistry of life itself.

I believe that this hypothesis if true has major implications for the built environment and how we live and the type of light that we require to live, and I believe it’s one of the major reasons why we need to be treating our patients outside.

Sources

• Jeffery et al. (2025) – Longer wavelengths in sunlight penetrating human tissue
• Ma et al. (2018) – Infrared perturbation of charge separation and recombination
• Sanderson et al. (2018) – Inhibitory modulation of cytochrome c oxidase with near-infrared wavelengths
• Dai et al. (2026) – Infrared stimulation of mitochondrial metabolism in deep-sea yeast
• Hayashi et al. (2010) – Water-mediated electron transfer in iron-sulfur bridges
• Marcus and Sutin (1985) – Electron transfer reactions in chemistry

A 2026 study by Dai and colleagues isolated yeast from sediments near a “black smoker” chimney in the central Indian Ocean, more than half a meter from superheated mineral plumes reaching 378°C.

When researchers exposed these yeast cultures to near-infrared light (810–1050 nm) in temperature-controlled conditions, growth increased dramatically compared to dark controls—even though the yeast cannot photosynthesize.

Infrared light outperformed glucose. Adding glucose increased biomass by only 1.3-fold (not statistically significant), while 880-nanometer infrared light produced a threefold increase.

When researchers blocked cytochrome c oxidase (complex IV in mitochondria), near-infrared-stimulated growth dropped by 44%—suggesting the effect operates directly on mitochondrial machinery.

Cold Temperatures, Warm Light

Even more remarkable: infrared light allowed yeast to grow at cooler temperatures where dark controls remained dormant.

At 20°C, yeast exposed to 880-nanometer light grew vigorously while dark controls showed minimal activity. The effective activation energy dropped from 12 kilocalories per mole to just 2 kilocalories per mole.

Infrared light was making up for the cold temperatures by supplying vibrational activation rather than thermal activation.

Proteomics revealed the most upregulated protein after infrared exposure was a mitochondrial ribosomal protein (MRPs8), increased 6.7-fold.

Why Broadband Sunlight May Beat Monochromatic LEDs

Clinical studies using single-wavelength infrared devices have shown benefits—from reducing ICU length of stay to improving muscle strength in COVID-19 patients.

But Seheult’s hypothesis suggests broadband infrared from the sun may be even more effective.

“Sunlight contains a broad spectrum of wavelengths that can interact with many different vibrational modes and electron transfer steps,” he explains, “rather than targeting only one narrow pathway.”

Research from Jeffery’s lab supports this. When comparing monochromatic 850-nanometer light to a 60-watt incandescent bulb (which emits broad-spectrum infrared), the incandescent bulb produced greater improvements in color blindness.

• Monochromatic 850 nm: 9% improvement (head and body), 5% (body only)
• 60W incandescent bulb: 28% improvement, sustained for weeks

The research here aligns with the hypothesis, though direct mechanistic proof in human mitochondria remains to be demonstrated.

The Modern Indoor Environment: A Metabolic Desert?

LED bulbs emit virtually no infrared radiation. Low-emissivity (Low-E) glass windows, designed to improve energy efficiency, block infrared wavelengths.

Seheult measured infrared exposure in his own dining room with windows open: 0.8 watts per square meter.

Step outside under a shade tree with grass reflecting sunlight? 41.9 watts per square meter—more than 50 times higher.

We have set up a situation where outdoors we’re getting plenty of infrared light, versus being indoors where we have Low-E glass blocking it and LED bulbs producing none.

This raises profound questions about whether chronic infrared deficiency could contribute to the rising burden of metabolic diseases, especially among populations spending most of their time indoors.

Seasonal Mortality Patterns Point to Sunlight’s Role

Death rates from heart disease, cancer, stroke, Alzheimer’s, diabetes, and respiratory illness all peak one to three weeks after the shortest day of the year and bottom out after the longest day.

This pattern holds across both infectious and non-infectious causes. The seasonal variation in heart disease deaths alone exceeds total influenza deaths during flu season.

Australia shows the same pattern, but shifted six months—deaths peak in July, their winter. Singapore, 80 miles from the equator with year-round sun, shows no seasonal mortality pattern.

Multiple studies have linked mortality rates to latitude, independent of vitamin D levels, suggesting sunlight itself—particularly its infrared component—plays a direct metabolic role.

Hospitals Are Bringing Patients Outside

Armed with mounting evidence, hospitals worldwide are redesigning care spaces to maximize sunlight exposure.

A $1.5 billion hospital in Footscray, Australia, built ICU beds with direct outdoor access. King’s College Hospital in London invested £2 million to transform its rooftop into a critical care garden where up to six ICU patients can receive treatment surrounded by greenery and natural light.

St. George’s Hospital in London followed suit, creating a neurointensive care rooftop unit. Queen Camilla visited the facility in 2026 to recognize the innovation.

Randomized controlled trials using infrared vests delivering roughly 20–30 watts per square meter (comparable to sitting under a tree) showed 30% reductions in ICU length of stay and improved muscle strength in critically ill COVID-19 patients.

Metabolic Scaling Matches Solar Power Scaling

One of the paper’s most intriguing observations: metabolic rate scales with body mass to the 3/4 power across species from flies to elephants.

Solar power intercepted by an organism also scales to the 3/4 power of mass—nearly identical.

This doesn’t prove causation, but it suggests sunlight could be a universal regulator of metabolic activity across the biosphere, with mitochondria in all organisms tuned to respond to the same infrared wavelengths present in Earth’s solar photon field.

What Makes This Hypothesis Different

Earlier theories proposed infrared light works by activating a photoreceptor in cytochrome c oxidase (complex IV) or by reducing water viscosity around ATP synthase motors.

Seheult’s team doesn’t reject these mechanisms—but argues they’re incomplete.

The Marcus framework explains phenomena earlier models couldn’t: why some infrared wavelengths inhibit rather than enhance mitochondrial activity, why broadband light outperforms monochromatic sources, and why effects persist across vastly different organisms.

The paper is the first to integrate four separate literature streams:

• Mitochondrial electron transfer follows Marcus physics
• Red and near-infrared light alter mitochondrial function
• Water and protein structures affect electron transfer kinetics
• Infrared radiation changes molecular electron transfer rates

“The novelty lies in the mechanistic integration,” Seheult emphasizes, “not in any single component.”

What Comes Next

The hypothesis is testable. Future experiments could measure how different infrared wavelengths alter specific Marcus crossing configurations in isolated mitochondrial complexes, or track real-time changes in reorganization energy using advanced spectroscopy.

If validated, the implications extend far beyond biology. Urban planning, architecture, workplace design, and lighting standards may all need reconsideration.

Seheult introduces a new term: photometabolism—solar-driven, non-photosynthetic modulation of core metabolic processes.

It’s a concept that positions sunlight not as a passive environmental factor, but as an active participant in the biochemistry of life itself.

I believe that this hypothesis if true has major implications for the built environment and how we live and the type of light that we require to live, and I believe it’s one of the major reasons why we need to be treating our patients outside.

Sources

• Jeffery et al. (2025) – Longer wavelengths in sunlight penetrating human tissue
• Ma et al. (2018) – Infrared perturbation of charge separation and recombination
• Sanderson et al. (2018) – Inhibitory modulation of cytochrome c oxidase with near-infrared wavelengths
• Dai et al. (2026) – Infrared stimulation of mitochondrial metabolism in deep-sea yeast
• Hayashi et al. (2010) – Water-mediated electron transfer in iron-sulfur bridges
• Marcus and Sutin (1985) – Electron transfer reactions in chemistry

Perhaps the most striking evidence comes from an unexpected source: yeast living near hydrothermal vents at the bottom of the ocean.

A 2026 study by Dai and colleagues isolated yeast from sediments near a “black smoker” chimney in the central Indian Ocean, more than half a meter from superheated mineral plumes reaching 378°C.

When researchers exposed these yeast cultures to near-infrared light (810–1050 nm) in temperature-controlled conditions, growth increased dramatically compared to dark controls—even though the yeast cannot photosynthesize.

Infrared light outperformed glucose. Adding glucose increased biomass by only 1.3-fold (not statistically significant), while 880-nanometer infrared light produced a threefold increase.

When researchers blocked cytochrome c oxidase (complex IV in mitochondria), near-infrared-stimulated growth dropped by 44%—suggesting the effect operates directly on mitochondrial machinery.

Cold Temperatures, Warm Light

Even more remarkable: infrared light allowed yeast to grow at cooler temperatures where dark controls remained dormant.

At 20°C, yeast exposed to 880-nanometer light grew vigorously while dark controls showed minimal activity. The effective activation energy dropped from 12 kilocalories per mole to just 2 kilocalories per mole.

Infrared light was making up for the cold temperatures by supplying vibrational activation rather than thermal activation.

Proteomics revealed the most upregulated protein after infrared exposure was a mitochondrial ribosomal protein (MRPs8), increased 6.7-fold.

Why Broadband Sunlight May Beat Monochromatic LEDs

Clinical studies using single-wavelength infrared devices have shown benefits—from reducing ICU length of stay to improving muscle strength in COVID-19 patients.

But Seheult’s hypothesis suggests broadband infrared from the sun may be even more effective.

“Sunlight contains a broad spectrum of wavelengths that can interact with many different vibrational modes and electron transfer steps,” he explains, “rather than targeting only one narrow pathway.”

Research from Jeffery’s lab supports this. When comparing monochromatic 850-nanometer light to a 60-watt incandescent bulb (which emits broad-spectrum infrared), the incandescent bulb produced greater improvements in color blindness.

• Monochromatic 850 nm: 9% improvement (head and body), 5% (body only)
• 60W incandescent bulb: 28% improvement, sustained for weeks

The research here aligns with the hypothesis, though direct mechanistic proof in human mitochondria remains to be demonstrated.

The Modern Indoor Environment: A Metabolic Desert?

LED bulbs emit virtually no infrared radiation. Low-emissivity (Low-E) glass windows, designed to improve energy efficiency, block infrared wavelengths.

Seheult measured infrared exposure in his own dining room with windows open: 0.8 watts per square meter.

Step outside under a shade tree with grass reflecting sunlight? 41.9 watts per square meter—more than 50 times higher.

We have set up a situation where outdoors we’re getting plenty of infrared light, versus being indoors where we have Low-E glass blocking it and LED bulbs producing none.

This raises profound questions about whether chronic infrared deficiency could contribute to the rising burden of metabolic diseases, especially among populations spending most of their time indoors.

Seasonal Mortality Patterns Point to Sunlight’s Role

Death rates from heart disease, cancer, stroke, Alzheimer’s, diabetes, and respiratory illness all peak one to three weeks after the shortest day of the year and bottom out after the longest day.

This pattern holds across both infectious and non-infectious causes. The seasonal variation in heart disease deaths alone exceeds total influenza deaths during flu season.

Australia shows the same pattern, but shifted six months—deaths peak in July, their winter. Singapore, 80 miles from the equator with year-round sun, shows no seasonal mortality pattern.

Multiple studies have linked mortality rates to latitude, independent of vitamin D levels, suggesting sunlight itself—particularly its infrared component—plays a direct metabolic role.

Hospitals Are Bringing Patients Outside

Armed with mounting evidence, hospitals worldwide are redesigning care spaces to maximize sunlight exposure.

A $1.5 billion hospital in Footscray, Australia, built ICU beds with direct outdoor access. King’s College Hospital in London invested £2 million to transform its rooftop into a critical care garden where up to six ICU patients can receive treatment surrounded by greenery and natural light.

St. George’s Hospital in London followed suit, creating a neurointensive care rooftop unit. Queen Camilla visited the facility in 2026 to recognize the innovation.

Randomized controlled trials using infrared vests delivering roughly 20–30 watts per square meter (comparable to sitting under a tree) showed 30% reductions in ICU length of stay and improved muscle strength in critically ill COVID-19 patients.

Metabolic Scaling Matches Solar Power Scaling

One of the paper’s most intriguing observations: metabolic rate scales with body mass to the 3/4 power across species from flies to elephants.

Solar power intercepted by an organism also scales to the 3/4 power of mass—nearly identical.

This doesn’t prove causation, but it suggests sunlight could be a universal regulator of metabolic activity across the biosphere, with mitochondria in all organisms tuned to respond to the same infrared wavelengths present in Earth’s solar photon field.

What Makes This Hypothesis Different

Earlier theories proposed infrared light works by activating a photoreceptor in cytochrome c oxidase (complex IV) or by reducing water viscosity around ATP synthase motors.

Seheult’s team doesn’t reject these mechanisms—but argues they’re incomplete.

The Marcus framework explains phenomena earlier models couldn’t: why some infrared wavelengths inhibit rather than enhance mitochondrial activity, why broadband light outperforms monochromatic sources, and why effects persist across vastly different organisms.

The paper is the first to integrate four separate literature streams:

• Mitochondrial electron transfer follows Marcus physics
• Red and near-infrared light alter mitochondrial function
• Water and protein structures affect electron transfer kinetics
• Infrared radiation changes molecular electron transfer rates

“The novelty lies in the mechanistic integration,” Seheult emphasizes, “not in any single component.”

What Comes Next

The hypothesis is testable. Future experiments could measure how different infrared wavelengths alter specific Marcus crossing configurations in isolated mitochondrial complexes, or track real-time changes in reorganization energy using advanced spectroscopy.

If validated, the implications extend far beyond biology. Urban planning, architecture, workplace design, and lighting standards may all need reconsideration.

Seheult introduces a new term: photometabolism—solar-driven, non-photosynthetic modulation of core metabolic processes.

It’s a concept that positions sunlight not as a passive environmental factor, but as an active participant in the biochemistry of life itself.

I believe that this hypothesis if true has major implications for the built environment and how we live and the type of light that we require to live, and I believe it’s one of the major reasons why we need to be treating our patients outside.

Sources

• Jeffery et al. (2025) – Longer wavelengths in sunlight penetrating human tissue
• Ma et al. (2018) – Infrared perturbation of charge separation and recombination
• Sanderson et al. (2018) – Inhibitory modulation of cytochrome c oxidase with near-infrared wavelengths
• Dai et al. (2026) – Infrared stimulation of mitochondrial metabolism in deep-sea yeast
• Hayashi et al. (2010) – Water-mediated electron transfer in iron-sulfur bridges
• Marcus and Sutin (1985) – Electron transfer reactions in chemistry

Perhaps the most striking evidence comes from an unexpected source: yeast living near hydrothermal vents at the bottom of the ocean.

A 2026 study by Dai and colleagues isolated yeast from sediments near a “black smoker” chimney in the central Indian Ocean, more than half a meter from superheated mineral plumes reaching 378°C.

When researchers exposed these yeast cultures to near-infrared light (810–1050 nm) in temperature-controlled conditions, growth increased dramatically compared to dark controls—even though the yeast cannot photosynthesize.

Infrared light outperformed glucose. Adding glucose increased biomass by only 1.3-fold (not statistically significant), while 880-nanometer infrared light produced a threefold increase.

When researchers blocked cytochrome c oxidase (complex IV in mitochondria), near-infrared-stimulated growth dropped by 44%—suggesting the effect operates directly on mitochondrial machinery.

Cold Temperatures, Warm Light

Even more remarkable: infrared light allowed yeast to grow at cooler temperatures where dark controls remained dormant.

At 20°C, yeast exposed to 880-nanometer light grew vigorously while dark controls showed minimal activity. The effective activation energy dropped from 12 kilocalories per mole to just 2 kilocalories per mole.

Infrared light was making up for the cold temperatures by supplying vibrational activation rather than thermal activation.

Proteomics revealed the most upregulated protein after infrared exposure was a mitochondrial ribosomal protein (MRPs8), increased 6.7-fold.

Why Broadband Sunlight May Beat Monochromatic LEDs

Clinical studies using single-wavelength infrared devices have shown benefits—from reducing ICU length of stay to improving muscle strength in COVID-19 patients.

But Seheult’s hypothesis suggests broadband infrared from the sun may be even more effective.

“Sunlight contains a broad spectrum of wavelengths that can interact with many different vibrational modes and electron transfer steps,” he explains, “rather than targeting only one narrow pathway.”

Research from Jeffery’s lab supports this. When comparing monochromatic 850-nanometer light to a 60-watt incandescent bulb (which emits broad-spectrum infrared), the incandescent bulb produced greater improvements in color blindness.

• Monochromatic 850 nm: 9% improvement (head and body), 5% (body only)
• 60W incandescent bulb: 28% improvement, sustained for weeks

The research here aligns with the hypothesis, though direct mechanistic proof in human mitochondria remains to be demonstrated.

The Modern Indoor Environment: A Metabolic Desert?

LED bulbs emit virtually no infrared radiation. Low-emissivity (Low-E) glass windows, designed to improve energy efficiency, block infrared wavelengths.

Seheult measured infrared exposure in his own dining room with windows open: 0.8 watts per square meter.

Step outside under a shade tree with grass reflecting sunlight? 41.9 watts per square meter—more than 50 times higher.

We have set up a situation where outdoors we’re getting plenty of infrared light, versus being indoors where we have Low-E glass blocking it and LED bulbs producing none.

This raises profound questions about whether chronic infrared deficiency could contribute to the rising burden of metabolic diseases, especially among populations spending most of their time indoors.

Seasonal Mortality Patterns Point to Sunlight’s Role

Death rates from heart disease, cancer, stroke, Alzheimer’s, diabetes, and respiratory illness all peak one to three weeks after the shortest day of the year and bottom out after the longest day.

This pattern holds across both infectious and non-infectious causes. The seasonal variation in heart disease deaths alone exceeds total influenza deaths during flu season.

Australia shows the same pattern, but shifted six months—deaths peak in July, their winter. Singapore, 80 miles from the equator with year-round sun, shows no seasonal mortality pattern.

Multiple studies have linked mortality rates to latitude, independent of vitamin D levels, suggesting sunlight itself—particularly its infrared component—plays a direct metabolic role.

Hospitals Are Bringing Patients Outside

Armed with mounting evidence, hospitals worldwide are redesigning care spaces to maximize sunlight exposure.

A $1.5 billion hospital in Footscray, Australia, built ICU beds with direct outdoor access. King’s College Hospital in London invested £2 million to transform its rooftop into a critical care garden where up to six ICU patients can receive treatment surrounded by greenery and natural light.

St. George’s Hospital in London followed suit, creating a neurointensive care rooftop unit. Queen Camilla visited the facility in 2026 to recognize the innovation.

Randomized controlled trials using infrared vests delivering roughly 20–30 watts per square meter (comparable to sitting under a tree) showed 30% reductions in ICU length of stay and improved muscle strength in critically ill COVID-19 patients.

Metabolic Scaling Matches Solar Power Scaling

One of the paper’s most intriguing observations: metabolic rate scales with body mass to the 3/4 power across species from flies to elephants.

Solar power intercepted by an organism also scales to the 3/4 power of mass—nearly identical.

This doesn’t prove causation, but it suggests sunlight could be a universal regulator of metabolic activity across the biosphere, with mitochondria in all organisms tuned to respond to the same infrared wavelengths present in Earth’s solar photon field.

What Makes This Hypothesis Different

Earlier theories proposed infrared light works by activating a photoreceptor in cytochrome c oxidase (complex IV) or by reducing water viscosity around ATP synthase motors.

Seheult’s team doesn’t reject these mechanisms—but argues they’re incomplete.

The Marcus framework explains phenomena earlier models couldn’t: why some infrared wavelengths inhibit rather than enhance mitochondrial activity, why broadband light outperforms monochromatic sources, and why effects persist across vastly different organisms.

The paper is the first to integrate four separate literature streams:

• Mitochondrial electron transfer follows Marcus physics
• Red and near-infrared light alter mitochondrial function
• Water and protein structures affect electron transfer kinetics
• Infrared radiation changes molecular electron transfer rates

“The novelty lies in the mechanistic integration,” Seheult emphasizes, “not in any single component.”

What Comes Next

The hypothesis is testable. Future experiments could measure how different infrared wavelengths alter specific Marcus crossing configurations in isolated mitochondrial complexes, or track real-time changes in reorganization energy using advanced spectroscopy.

If validated, the implications extend far beyond biology. Urban planning, architecture, workplace design, and lighting standards may all need reconsideration.

Seheult introduces a new term: photometabolism—solar-driven, non-photosynthetic modulation of core metabolic processes.

It’s a concept that positions sunlight not as a passive environmental factor, but as an active participant in the biochemistry of life itself.

I believe that this hypothesis if true has major implications for the built environment and how we live and the type of light that we require to live, and I believe it’s one of the major reasons why we need to be treating our patients outside.

Sources

• Jeffery et al. (2025) – Longer wavelengths in sunlight penetrating human tissue
• Ma et al. (2018) – Infrared perturbation of charge separation and recombination
• Sanderson et al. (2018) – Inhibitory modulation of cytochrome c oxidase with near-infrared wavelengths
• Dai et al. (2026) – Infrared stimulation of mitochondrial metabolism in deep-sea yeast
• Hayashi et al. (2010) – Water-mediated electron transfer in iron-sulfur bridges
• Marcus and Sutin (1985) – Electron transfer reactions in chemistry

Deep-Sea Yeast Thrives on Infrared Light—Without Photosynthesis

Perhaps the most striking evidence comes from an unexpected source: yeast living near hydrothermal vents at the bottom of the ocean.

A 2026 study by Dai and colleagues isolated yeast from sediments near a “black smoker” chimney in the central Indian Ocean, more than half a meter from superheated mineral plumes reaching 378°C.

When researchers exposed these yeast cultures to near-infrared light (810–1050 nm) in temperature-controlled conditions, growth increased dramatically compared to dark controls—even though the yeast cannot photosynthesize.

Infrared light outperformed glucose. Adding glucose increased biomass by only 1.3-fold (not statistically significant), while 880-nanometer infrared light produced a threefold increase.

When researchers blocked cytochrome c oxidase (complex IV in mitochondria), near-infrared-stimulated growth dropped by 44%—suggesting the effect operates directly on mitochondrial machinery.

Cold Temperatures, Warm Light

Even more remarkable: infrared light allowed yeast to grow at cooler temperatures where dark controls remained dormant.

At 20°C, yeast exposed to 880-nanometer light grew vigorously while dark controls showed minimal activity. The effective activation energy dropped from 12 kilocalories per mole to just 2 kilocalories per mole.

Infrared light was making up for the cold temperatures by supplying vibrational activation rather than thermal activation.

Proteomics revealed the most upregulated protein after infrared exposure was a mitochondrial ribosomal protein (MRPs8), increased 6.7-fold.

Why Broadband Sunlight May Beat Monochromatic LEDs

Clinical studies using single-wavelength infrared devices have shown benefits—from reducing ICU length of stay to improving muscle strength in COVID-19 patients.

But Seheult’s hypothesis suggests broadband infrared from the sun may be even more effective.

“Sunlight contains a broad spectrum of wavelengths that can interact with many different vibrational modes and electron transfer steps,” he explains, “rather than targeting only one narrow pathway.”

Research from Jeffery’s lab supports this. When comparing monochromatic 850-nanometer light to a 60-watt incandescent bulb (which emits broad-spectrum infrared), the incandescent bulb produced greater improvements in color blindness.

• Monochromatic 850 nm: 9% improvement (head and body), 5% (body only)
• 60W incandescent bulb: 28% improvement, sustained for weeks

The research here aligns with the hypothesis, though direct mechanistic proof in human mitochondria remains to be demonstrated.

The Modern Indoor Environment: A Metabolic Desert?

LED bulbs emit virtually no infrared radiation. Low-emissivity (Low-E) glass windows, designed to improve energy efficiency, block infrared wavelengths.

Seheult measured infrared exposure in his own dining room with windows open: 0.8 watts per square meter.

Step outside under a shade tree with grass reflecting sunlight? 41.9 watts per square meter—more than 50 times higher.

We have set up a situation where outdoors we’re getting plenty of infrared light, versus being indoors where we have Low-E glass blocking it and LED bulbs producing none.

This raises profound questions about whether chronic infrared deficiency could contribute to the rising burden of metabolic diseases, especially among populations spending most of their time indoors.

Seasonal Mortality Patterns Point to Sunlight’s Role

Death rates from heart disease, cancer, stroke, Alzheimer’s, diabetes, and respiratory illness all peak one to three weeks after the shortest day of the year and bottom out after the longest day.

This pattern holds across both infectious and non-infectious causes. The seasonal variation in heart disease deaths alone exceeds total influenza deaths during flu season.

Australia shows the same pattern, but shifted six months—deaths peak in July, their winter. Singapore, 80 miles from the equator with year-round sun, shows no seasonal mortality pattern.

Multiple studies have linked mortality rates to latitude, independent of vitamin D levels, suggesting sunlight itself—particularly its infrared component—plays a direct metabolic role.

Hospitals Are Bringing Patients Outside

Armed with mounting evidence, hospitals worldwide are redesigning care spaces to maximize sunlight exposure.

A $1.5 billion hospital in Footscray, Australia, built ICU beds with direct outdoor access. King’s College Hospital in London invested £2 million to transform its rooftop into a critical care garden where up to six ICU patients can receive treatment surrounded by greenery and natural light.

St. George’s Hospital in London followed suit, creating a neurointensive care rooftop unit. Queen Camilla visited the facility in 2026 to recognize the innovation.

Randomized controlled trials using infrared vests delivering roughly 20–30 watts per square meter (comparable to sitting under a tree) showed 30% reductions in ICU length of stay and improved muscle strength in critically ill COVID-19 patients.

Metabolic Scaling Matches Solar Power Scaling

One of the paper’s most intriguing observations: metabolic rate scales with body mass to the 3/4 power across species from flies to elephants.

Solar power intercepted by an organism also scales to the 3/4 power of mass—nearly identical.

This doesn’t prove causation, but it suggests sunlight could be a universal regulator of metabolic activity across the biosphere, with mitochondria in all organisms tuned to respond to the same infrared wavelengths present in Earth’s solar photon field.

What Makes This Hypothesis Different

Earlier theories proposed infrared light works by activating a photoreceptor in cytochrome c oxidase (complex IV) or by reducing water viscosity around ATP synthase motors.

Seheult’s team doesn’t reject these mechanisms—but argues they’re incomplete.

The Marcus framework explains phenomena earlier models couldn’t: why some infrared wavelengths inhibit rather than enhance mitochondrial activity, why broadband light outperforms monochromatic sources, and why effects persist across vastly different organisms.

The paper is the first to integrate four separate literature streams:

• Mitochondrial electron transfer follows Marcus physics
• Red and near-infrared light alter mitochondrial function
• Water and protein structures affect electron transfer kinetics
• Infrared radiation changes molecular electron transfer rates

“The novelty lies in the mechanistic integration,” Seheult emphasizes, “not in any single component.”

What Comes Next

The hypothesis is testable. Future experiments could measure how different infrared wavelengths alter specific Marcus crossing configurations in isolated mitochondrial complexes, or track real-time changes in reorganization energy using advanced spectroscopy.

If validated, the implications extend far beyond biology. Urban planning, architecture, workplace design, and lighting standards may all need reconsideration.

Seheult introduces a new term: photometabolism—solar-driven, non-photosynthetic modulation of core metabolic processes.

It’s a concept that positions sunlight not as a passive environmental factor, but as an active participant in the biochemistry of life itself.

I believe that this hypothesis if true has major implications for the built environment and how we live and the type of light that we require to live, and I believe it’s one of the major reasons why we need to be treating our patients outside.

Sources

• Jeffery et al. (2025) – Longer wavelengths in sunlight penetrating human tissue
• Ma et al. (2018) – Infrared perturbation of charge separation and recombination
• Sanderson et al. (2018) – Inhibitory modulation of cytochrome c oxidase with near-infrared wavelengths
• Dai et al. (2026) – Infrared stimulation of mitochondrial metabolism in deep-sea yeast
• Hayashi et al. (2010) – Water-mediated electron transfer in iron-sulfur bridges
• Marcus and Sutin (1985) – Electron transfer reactions in chemistry

Deep-Sea Yeast Thrives on Infrared Light—Without Photosynthesis

Perhaps the most striking evidence comes from an unexpected source: yeast living near hydrothermal vents at the bottom of the ocean.

A 2026 study by Dai and colleagues isolated yeast from sediments near a “black smoker” chimney in the central Indian Ocean, more than half a meter from superheated mineral plumes reaching 378°C.

When researchers exposed these yeast cultures to near-infrared light (810–1050 nm) in temperature-controlled conditions, growth increased dramatically compared to dark controls—even though the yeast cannot photosynthesize.

Infrared light outperformed glucose. Adding glucose increased biomass by only 1.3-fold (not statistically significant), while 880-nanometer infrared light produced a threefold increase.

When researchers blocked cytochrome c oxidase (complex IV in mitochondria), near-infrared-stimulated growth dropped by 44%—suggesting the effect operates directly on mitochondrial machinery.

Cold Temperatures, Warm Light

Even more remarkable: infrared light allowed yeast to grow at cooler temperatures where dark controls remained dormant.

At 20°C, yeast exposed to 880-nanometer light grew vigorously while dark controls showed minimal activity. The effective activation energy dropped from 12 kilocalories per mole to just 2 kilocalories per mole.

Infrared light was making up for the cold temperatures by supplying vibrational activation rather than thermal activation.

Proteomics revealed the most upregulated protein after infrared exposure was a mitochondrial ribosomal protein (MRPs8), increased 6.7-fold.

Why Broadband Sunlight May Beat Monochromatic LEDs

Clinical studies using single-wavelength infrared devices have shown benefits—from reducing ICU length of stay to improving muscle strength in COVID-19 patients.

But Seheult’s hypothesis suggests broadband infrared from the sun may be even more effective.

“Sunlight contains a broad spectrum of wavelengths that can interact with many different vibrational modes and electron transfer steps,” he explains, “rather than targeting only one narrow pathway.”

Research from Jeffery’s lab supports this. When comparing monochromatic 850-nanometer light to a 60-watt incandescent bulb (which emits broad-spectrum infrared), the incandescent bulb produced greater improvements in color blindness.

• Monochromatic 850 nm: 9% improvement (head and body), 5% (body only)
• 60W incandescent bulb: 28% improvement, sustained for weeks

The research here aligns with the hypothesis, though direct mechanistic proof in human mitochondria remains to be demonstrated.

The Modern Indoor Environment: A Metabolic Desert?

LED bulbs emit virtually no infrared radiation. Low-emissivity (Low-E) glass windows, designed to improve energy efficiency, block infrared wavelengths.

Seheult measured infrared exposure in his own dining room with windows open: 0.8 watts per square meter.

Step outside under a shade tree with grass reflecting sunlight? 41.9 watts per square meter—more than 50 times higher.

We have set up a situation where outdoors we’re getting plenty of infrared light, versus being indoors where we have Low-E glass blocking it and LED bulbs producing none.

This raises profound questions about whether chronic infrared deficiency could contribute to the rising burden of metabolic diseases, especially among populations spending most of their time indoors.

Seasonal Mortality Patterns Point to Sunlight’s Role

Death rates from heart disease, cancer, stroke, Alzheimer’s, diabetes, and respiratory illness all peak one to three weeks after the shortest day of the year and bottom out after the longest day.

This pattern holds across both infectious and non-infectious causes. The seasonal variation in heart disease deaths alone exceeds total influenza deaths during flu season.

Australia shows the same pattern, but shifted six months—deaths peak in July, their winter. Singapore, 80 miles from the equator with year-round sun, shows no seasonal mortality pattern.

Multiple studies have linked mortality rates to latitude, independent of vitamin D levels, suggesting sunlight itself—particularly its infrared component—plays a direct metabolic role.

Hospitals Are Bringing Patients Outside

Armed with mounting evidence, hospitals worldwide are redesigning care spaces to maximize sunlight exposure.

A $1.5 billion hospital in Footscray, Australia, built ICU beds with direct outdoor access. King’s College Hospital in London invested £2 million to transform its rooftop into a critical care garden where up to six ICU patients can receive treatment surrounded by greenery and natural light.

St. George’s Hospital in London followed suit, creating a neurointensive care rooftop unit. Queen Camilla visited the facility in 2026 to recognize the innovation.

Randomized controlled trials using infrared vests delivering roughly 20–30 watts per square meter (comparable to sitting under a tree) showed 30% reductions in ICU length of stay and improved muscle strength in critically ill COVID-19 patients.

Metabolic Scaling Matches Solar Power Scaling

One of the paper’s most intriguing observations: metabolic rate scales with body mass to the 3/4 power across species from flies to elephants.

Solar power intercepted by an organism also scales to the 3/4 power of mass—nearly identical.

This doesn’t prove causation, but it suggests sunlight could be a universal regulator of metabolic activity across the biosphere, with mitochondria in all organisms tuned to respond to the same infrared wavelengths present in Earth’s solar photon field.

What Makes This Hypothesis Different

Earlier theories proposed infrared light works by activating a photoreceptor in cytochrome c oxidase (complex IV) or by reducing water viscosity around ATP synthase motors.

Seheult’s team doesn’t reject these mechanisms—but argues they’re incomplete.

The Marcus framework explains phenomena earlier models couldn’t: why some infrared wavelengths inhibit rather than enhance mitochondrial activity, why broadband light outperforms monochromatic sources, and why effects persist across vastly different organisms.

The paper is the first to integrate four separate literature streams:

• Mitochondrial electron transfer follows Marcus physics
• Red and near-infrared light alter mitochondrial function
• Water and protein structures affect electron transfer kinetics
• Infrared radiation changes molecular electron transfer rates

“The novelty lies in the mechanistic integration,” Seheult emphasizes, “not in any single component.”

What Comes Next

The hypothesis is testable. Future experiments could measure how different infrared wavelengths alter specific Marcus crossing configurations in isolated mitochondrial complexes, or track real-time changes in reorganization energy using advanced spectroscopy.

If validated, the implications extend far beyond biology. Urban planning, architecture, workplace design, and lighting standards may all need reconsideration.

Seheult introduces a new term: photometabolism—solar-driven, non-photosynthetic modulation of core metabolic processes.

It’s a concept that positions sunlight not as a passive environmental factor, but as an active participant in the biochemistry of life itself.

I believe that this hypothesis if true has major implications for the built environment and how we live and the type of light that we require to live, and I believe it’s one of the major reasons why we need to be treating our patients outside.

Sources

• Jeffery et al. (2025) – Longer wavelengths in sunlight penetrating human tissue
• Ma et al. (2018) – Infrared perturbation of charge separation and recombination
• Sanderson et al. (2018) – Inhibitory modulation of cytochrome c oxidase with near-infrared wavelengths
• Dai et al. (2026) – Infrared stimulation of mitochondrial metabolism in deep-sea yeast
• Hayashi et al. (2010) – Water-mediated electron transfer in iron-sulfur bridges
• Marcus and Sutin (1985) – Electron transfer reactions in chemistry

Seheult notes he and co-author Dr. Robert Fosbury spoke with Marcus himself—just months before the scientist passed away at age 102—to discuss their hypothesis.

Deep-Sea Yeast Thrives on Infrared Light—Without Photosynthesis

Perhaps the most striking evidence comes from an unexpected source: yeast living near hydrothermal vents at the bottom of the ocean.

A 2026 study by Dai and colleagues isolated yeast from sediments near a “black smoker” chimney in the central Indian Ocean, more than half a meter from superheated mineral plumes reaching 378°C.

When researchers exposed these yeast cultures to near-infrared light (810–1050 nm) in temperature-controlled conditions, growth increased dramatically compared to dark controls—even though the yeast cannot photosynthesize.

Infrared light outperformed glucose. Adding glucose increased biomass by only 1.3-fold (not statistically significant), while 880-nanometer infrared light produced a threefold increase.

When researchers blocked cytochrome c oxidase (complex IV in mitochondria), near-infrared-stimulated growth dropped by 44%—suggesting the effect operates directly on mitochondrial machinery.

Cold Temperatures, Warm Light

Even more remarkable: infrared light allowed yeast to grow at cooler temperatures where dark controls remained dormant.

At 20°C, yeast exposed to 880-nanometer light grew vigorously while dark controls showed minimal activity. The effective activation energy dropped from 12 kilocalories per mole to just 2 kilocalories per mole.

Infrared light was making up for the cold temperatures by supplying vibrational activation rather than thermal activation.

Proteomics revealed the most upregulated protein after infrared exposure was a mitochondrial ribosomal protein (MRPs8), increased 6.7-fold.

Why Broadband Sunlight May Beat Monochromatic LEDs

Clinical studies using single-wavelength infrared devices have shown benefits—from reducing ICU length of stay to improving muscle strength in COVID-19 patients.

But Seheult’s hypothesis suggests broadband infrared from the sun may be even more effective.

“Sunlight contains a broad spectrum of wavelengths that can interact with many different vibrational modes and electron transfer steps,” he explains, “rather than targeting only one narrow pathway.”

Research from Jeffery’s lab supports this. When comparing monochromatic 850-nanometer light to a 60-watt incandescent bulb (which emits broad-spectrum infrared), the incandescent bulb produced greater improvements in color blindness.

• Monochromatic 850 nm: 9% improvement (head and body), 5% (body only)
• 60W incandescent bulb: 28% improvement, sustained for weeks

The research here aligns with the hypothesis, though direct mechanistic proof in human mitochondria remains to be demonstrated.

The Modern Indoor Environment: A Metabolic Desert?

LED bulbs emit virtually no infrared radiation. Low-emissivity (Low-E) glass windows, designed to improve energy efficiency, block infrared wavelengths.

Seheult measured infrared exposure in his own dining room with windows open: 0.8 watts per square meter.

Step outside under a shade tree with grass reflecting sunlight? 41.9 watts per square meter—more than 50 times higher.

We have set up a situation where outdoors we’re getting plenty of infrared light, versus being indoors where we have Low-E glass blocking it and LED bulbs producing none.

This raises profound questions about whether chronic infrared deficiency could contribute to the rising burden of metabolic diseases, especially among populations spending most of their time indoors.

Seasonal Mortality Patterns Point to Sunlight’s Role

Death rates from heart disease, cancer, stroke, Alzheimer’s, diabetes, and respiratory illness all peak one to three weeks after the shortest day of the year and bottom out after the longest day.

This pattern holds across both infectious and non-infectious causes. The seasonal variation in heart disease deaths alone exceeds total influenza deaths during flu season.

Australia shows the same pattern, but shifted six months—deaths peak in July, their winter. Singapore, 80 miles from the equator with year-round sun, shows no seasonal mortality pattern.

Multiple studies have linked mortality rates to latitude, independent of vitamin D levels, suggesting sunlight itself—particularly its infrared component—plays a direct metabolic role.

Hospitals Are Bringing Patients Outside

Armed with mounting evidence, hospitals worldwide are redesigning care spaces to maximize sunlight exposure.

A $1.5 billion hospital in Footscray, Australia, built ICU beds with direct outdoor access. King’s College Hospital in London invested £2 million to transform its rooftop into a critical care garden where up to six ICU patients can receive treatment surrounded by greenery and natural light.

St. George’s Hospital in London followed suit, creating a neurointensive care rooftop unit. Queen Camilla visited the facility in 2026 to recognize the innovation.

Randomized controlled trials using infrared vests delivering roughly 20–30 watts per square meter (comparable to sitting under a tree) showed 30% reductions in ICU length of stay and improved muscle strength in critically ill COVID-19 patients.

Metabolic Scaling Matches Solar Power Scaling

One of the paper’s most intriguing observations: metabolic rate scales with body mass to the 3/4 power across species from flies to elephants.

Solar power intercepted by an organism also scales to the 3/4 power of mass—nearly identical.

This doesn’t prove causation, but it suggests sunlight could be a universal regulator of metabolic activity across the biosphere, with mitochondria in all organisms tuned to respond to the same infrared wavelengths present in Earth’s solar photon field.

What Makes This Hypothesis Different

Earlier theories proposed infrared light works by activating a photoreceptor in cytochrome c oxidase (complex IV) or by reducing water viscosity around ATP synthase motors.

Seheult’s team doesn’t reject these mechanisms—but argues they’re incomplete.

The Marcus framework explains phenomena earlier models couldn’t: why some infrared wavelengths inhibit rather than enhance mitochondrial activity, why broadband light outperforms monochromatic sources, and why effects persist across vastly different organisms.

The paper is the first to integrate four separate literature streams:

• Mitochondrial electron transfer follows Marcus physics
• Red and near-infrared light alter mitochondrial function
• Water and protein structures affect electron transfer kinetics
• Infrared radiation changes molecular electron transfer rates

“The novelty lies in the mechanistic integration,” Seheult emphasizes, “not in any single component.”

What Comes Next

The hypothesis is testable. Future experiments could measure how different infrared wavelengths alter specific Marcus crossing configurations in isolated mitochondrial complexes, or track real-time changes in reorganization energy using advanced spectroscopy.

If validated, the implications extend far beyond biology. Urban planning, architecture, workplace design, and lighting standards may all need reconsideration.

Seheult introduces a new term: photometabolism—solar-driven, non-photosynthetic modulation of core metabolic processes.

It’s a concept that positions sunlight not as a passive environmental factor, but as an active participant in the biochemistry of life itself.

I believe that this hypothesis if true has major implications for the built environment and how we live and the type of light that we require to live, and I believe it’s one of the major reasons why we need to be treating our patients outside.

Sources

• Jeffery et al. (2025) – Longer wavelengths in sunlight penetrating human tissue
• Ma et al. (2018) – Infrared perturbation of charge separation and recombination
• Sanderson et al. (2018) – Inhibitory modulation of cytochrome c oxidase with near-infrared wavelengths
• Dai et al. (2026) – Infrared stimulation of mitochondrial metabolism in deep-sea yeast
• Hayashi et al. (2010) – Water-mediated electron transfer in iron-sulfur bridges
• Marcus and Sutin (1985) – Electron transfer reactions in chemistry

Seheult notes he and co-author Dr. Robert Fosbury spoke with Marcus himself—just months before the scientist passed away at age 102—to discuss their hypothesis.

Deep-Sea Yeast Thrives on Infrared Light—Without Photosynthesis

Perhaps the most striking evidence comes from an unexpected source: yeast living near hydrothermal vents at the bottom of the ocean.

A 2026 study by Dai and colleagues isolated yeast from sediments near a “black smoker” chimney in the central Indian Ocean, more than half a meter from superheated mineral plumes reaching 378°C.

When researchers exposed these yeast cultures to near-infrared light (810–1050 nm) in temperature-controlled conditions, growth increased dramatically compared to dark controls—even though the yeast cannot photosynthesize.

Infrared light outperformed glucose. Adding glucose increased biomass by only 1.3-fold (not statistically significant), while 880-nanometer infrared light produced a threefold increase.

When researchers blocked cytochrome c oxidase (complex IV in mitochondria), near-infrared-stimulated growth dropped by 44%—suggesting the effect operates directly on mitochondrial machinery.

Cold Temperatures, Warm Light

Even more remarkable: infrared light allowed yeast to grow at cooler temperatures where dark controls remained dormant.

At 20°C, yeast exposed to 880-nanometer light grew vigorously while dark controls showed minimal activity. The effective activation energy dropped from 12 kilocalories per mole to just 2 kilocalories per mole.

Infrared light was making up for the cold temperatures by supplying vibrational activation rather than thermal activation.

Proteomics revealed the most upregulated protein after infrared exposure was a mitochondrial ribosomal protein (MRPs8), increased 6.7-fold.

Why Broadband Sunlight May Beat Monochromatic LEDs

Clinical studies using single-wavelength infrared devices have shown benefits—from reducing ICU length of stay to improving muscle strength in COVID-19 patients.

But Seheult’s hypothesis suggests broadband infrared from the sun may be even more effective.

“Sunlight contains a broad spectrum of wavelengths that can interact with many different vibrational modes and electron transfer steps,” he explains, “rather than targeting only one narrow pathway.”

Research from Jeffery’s lab supports this. When comparing monochromatic 850-nanometer light to a 60-watt incandescent bulb (which emits broad-spectrum infrared), the incandescent bulb produced greater improvements in color blindness.

• Monochromatic 850 nm: 9% improvement (head and body), 5% (body only)
• 60W incandescent bulb: 28% improvement, sustained for weeks

The research here aligns with the hypothesis, though direct mechanistic proof in human mitochondria remains to be demonstrated.

The Modern Indoor Environment: A Metabolic Desert?

LED bulbs emit virtually no infrared radiation. Low-emissivity (Low-E) glass windows, designed to improve energy efficiency, block infrared wavelengths.

Seheult measured infrared exposure in his own dining room with windows open: 0.8 watts per square meter.

Step outside under a shade tree with grass reflecting sunlight? 41.9 watts per square meter—more than 50 times higher.

We have set up a situation where outdoors we’re getting plenty of infrared light, versus being indoors where we have Low-E glass blocking it and LED bulbs producing none.

This raises profound questions about whether chronic infrared deficiency could contribute to the rising burden of metabolic diseases, especially among populations spending most of their time indoors.

Seasonal Mortality Patterns Point to Sunlight’s Role

Death rates from heart disease, cancer, stroke, Alzheimer’s, diabetes, and respiratory illness all peak one to three weeks after the shortest day of the year and bottom out after the longest day.

This pattern holds across both infectious and non-infectious causes. The seasonal variation in heart disease deaths alone exceeds total influenza deaths during flu season.

Australia shows the same pattern, but shifted six months—deaths peak in July, their winter. Singapore, 80 miles from the equator with year-round sun, shows no seasonal mortality pattern.

Multiple studies have linked mortality rates to latitude, independent of vitamin D levels, suggesting sunlight itself—particularly its infrared component—plays a direct metabolic role.

Hospitals Are Bringing Patients Outside

Armed with mounting evidence, hospitals worldwide are redesigning care spaces to maximize sunlight exposure.

A $1.5 billion hospital in Footscray, Australia, built ICU beds with direct outdoor access. King’s College Hospital in London invested £2 million to transform its rooftop into a critical care garden where up to six ICU patients can receive treatment surrounded by greenery and natural light.

St. George’s Hospital in London followed suit, creating a neurointensive care rooftop unit. Queen Camilla visited the facility in 2026 to recognize the innovation.

Randomized controlled trials using infrared vests delivering roughly 20–30 watts per square meter (comparable to sitting under a tree) showed 30% reductions in ICU length of stay and improved muscle strength in critically ill COVID-19 patients.

Metabolic Scaling Matches Solar Power Scaling

One of the paper’s most intriguing observations: metabolic rate scales with body mass to the 3/4 power across species from flies to elephants.

Solar power intercepted by an organism also scales to the 3/4 power of mass—nearly identical.

This doesn’t prove causation, but it suggests sunlight could be a universal regulator of metabolic activity across the biosphere, with mitochondria in all organisms tuned to respond to the same infrared wavelengths present in Earth’s solar photon field.

What Makes This Hypothesis Different

Earlier theories proposed infrared light works by activating a photoreceptor in cytochrome c oxidase (complex IV) or by reducing water viscosity around ATP synthase motors.

Seheult’s team doesn’t reject these mechanisms—but argues they’re incomplete.

The Marcus framework explains phenomena earlier models couldn’t: why some infrared wavelengths inhibit rather than enhance mitochondrial activity, why broadband light outperforms monochromatic sources, and why effects persist across vastly different organisms.

The paper is the first to integrate four separate literature streams:

• Mitochondrial electron transfer follows Marcus physics
• Red and near-infrared light alter mitochondrial function
• Water and protein structures affect electron transfer kinetics
• Infrared radiation changes molecular electron transfer rates

“The novelty lies in the mechanistic integration,” Seheult emphasizes, “not in any single component.”

What Comes Next

The hypothesis is testable. Future experiments could measure how different infrared wavelengths alter specific Marcus crossing configurations in isolated mitochondrial complexes, or track real-time changes in reorganization energy using advanced spectroscopy.

If validated, the implications extend far beyond biology. Urban planning, architecture, workplace design, and lighting standards may all need reconsideration.

Seheult introduces a new term: photometabolism—solar-driven, non-photosynthetic modulation of core metabolic processes.

It’s a concept that positions sunlight not as a passive environmental factor, but as an active participant in the biochemistry of life itself.

I believe that this hypothesis if true has major implications for the built environment and how we live and the type of light that we require to live, and I believe it’s one of the major reasons why we need to be treating our patients outside.

Sources

• Jeffery et al. (2025) – Longer wavelengths in sunlight penetrating human tissue
• Ma et al. (2018) – Infrared perturbation of charge separation and recombination
• Sanderson et al. (2018) – Inhibitory modulation of cytochrome c oxidase with near-infrared wavelengths
• Dai et al. (2026) – Infrared stimulation of mitochondrial metabolism in deep-sea yeast
• Hayashi et al. (2010) – Water-mediated electron transfer in iron-sulfur bridges
• Marcus and Sutin (1985) – Electron transfer reactions in chemistry

IR excitation increases the probability of donor and acceptor energies to remain in degeneracy, resulting in IR-induced electron transfer rate enhancement.

Seheult notes he and co-author Dr. Robert Fosbury spoke with Marcus himself—just months before the scientist passed away at age 102—to discuss their hypothesis.

Deep-Sea Yeast Thrives on Infrared Light—Without Photosynthesis

Perhaps the most striking evidence comes from an unexpected source: yeast living near hydrothermal vents at the bottom of the ocean.

A 2026 study by Dai and colleagues isolated yeast from sediments near a “black smoker” chimney in the central Indian Ocean, more than half a meter from superheated mineral plumes reaching 378°C.

When researchers exposed these yeast cultures to near-infrared light (810–1050 nm) in temperature-controlled conditions, growth increased dramatically compared to dark controls—even though the yeast cannot photosynthesize.

Infrared light outperformed glucose. Adding glucose increased biomass by only 1.3-fold (not statistically significant), while 880-nanometer infrared light produced a threefold increase.

When researchers blocked cytochrome c oxidase (complex IV in mitochondria), near-infrared-stimulated growth dropped by 44%—suggesting the effect operates directly on mitochondrial machinery.

Cold Temperatures, Warm Light

Even more remarkable: infrared light allowed yeast to grow at cooler temperatures where dark controls remained dormant.

At 20°C, yeast exposed to 880-nanometer light grew vigorously while dark controls showed minimal activity. The effective activation energy dropped from 12 kilocalories per mole to just 2 kilocalories per mole.

Infrared light was making up for the cold temperatures by supplying vibrational activation rather than thermal activation.

Proteomics revealed the most upregulated protein after infrared exposure was a mitochondrial ribosomal protein (MRPs8), increased 6.7-fold.

Why Broadband Sunlight May Beat Monochromatic LEDs

Clinical studies using single-wavelength infrared devices have shown benefits—from reducing ICU length of stay to improving muscle strength in COVID-19 patients.

But Seheult’s hypothesis suggests broadband infrared from the sun may be even more effective.

“Sunlight contains a broad spectrum of wavelengths that can interact with many different vibrational modes and electron transfer steps,” he explains, “rather than targeting only one narrow pathway.”

Research from Jeffery’s lab supports this. When comparing monochromatic 850-nanometer light to a 60-watt incandescent bulb (which emits broad-spectrum infrared), the incandescent bulb produced greater improvements in color blindness.

• Monochromatic 850 nm: 9% improvement (head and body), 5% (body only)
• 60W incandescent bulb: 28% improvement, sustained for weeks

The research here aligns with the hypothesis, though direct mechanistic proof in human mitochondria remains to be demonstrated.

The Modern Indoor Environment: A Metabolic Desert?

LED bulbs emit virtually no infrared radiation. Low-emissivity (Low-E) glass windows, designed to improve energy efficiency, block infrared wavelengths.

Seheult measured infrared exposure in his own dining room with windows open: 0.8 watts per square meter.

Step outside under a shade tree with grass reflecting sunlight? 41.9 watts per square meter—more than 50 times higher.

We have set up a situation where outdoors we’re getting plenty of infrared light, versus being indoors where we have Low-E glass blocking it and LED bulbs producing none.

This raises profound questions about whether chronic infrared deficiency could contribute to the rising burden of metabolic diseases, especially among populations spending most of their time indoors.

Seasonal Mortality Patterns Point to Sunlight’s Role

Death rates from heart disease, cancer, stroke, Alzheimer’s, diabetes, and respiratory illness all peak one to three weeks after the shortest day of the year and bottom out after the longest day.

This pattern holds across both infectious and non-infectious causes. The seasonal variation in heart disease deaths alone exceeds total influenza deaths during flu season.

Australia shows the same pattern, but shifted six months—deaths peak in July, their winter. Singapore, 80 miles from the equator with year-round sun, shows no seasonal mortality pattern.

Multiple studies have linked mortality rates to latitude, independent of vitamin D levels, suggesting sunlight itself—particularly its infrared component—plays a direct metabolic role.

Hospitals Are Bringing Patients Outside

Armed with mounting evidence, hospitals worldwide are redesigning care spaces to maximize sunlight exposure.

A $1.5 billion hospital in Footscray, Australia, built ICU beds with direct outdoor access. King’s College Hospital in London invested £2 million to transform its rooftop into a critical care garden where up to six ICU patients can receive treatment surrounded by greenery and natural light.

St. George’s Hospital in London followed suit, creating a neurointensive care rooftop unit. Queen Camilla visited the facility in 2026 to recognize the innovation.

Randomized controlled trials using infrared vests delivering roughly 20–30 watts per square meter (comparable to sitting under a tree) showed 30% reductions in ICU length of stay and improved muscle strength in critically ill COVID-19 patients.

Metabolic Scaling Matches Solar Power Scaling

One of the paper’s most intriguing observations: metabolic rate scales with body mass to the 3/4 power across species from flies to elephants.

Solar power intercepted by an organism also scales to the 3/4 power of mass—nearly identical.

This doesn’t prove causation, but it suggests sunlight could be a universal regulator of metabolic activity across the biosphere, with mitochondria in all organisms tuned to respond to the same infrared wavelengths present in Earth’s solar photon field.

What Makes This Hypothesis Different

Earlier theories proposed infrared light works by activating a photoreceptor in cytochrome c oxidase (complex IV) or by reducing water viscosity around ATP synthase motors.

Seheult’s team doesn’t reject these mechanisms—but argues they’re incomplete.

The Marcus framework explains phenomena earlier models couldn’t: why some infrared wavelengths inhibit rather than enhance mitochondrial activity, why broadband light outperforms monochromatic sources, and why effects persist across vastly different organisms.

The paper is the first to integrate four separate literature streams:

• Mitochondrial electron transfer follows Marcus physics
• Red and near-infrared light alter mitochondrial function
• Water and protein structures affect electron transfer kinetics
• Infrared radiation changes molecular electron transfer rates

“The novelty lies in the mechanistic integration,” Seheult emphasizes, “not in any single component.”

What Comes Next

The hypothesis is testable. Future experiments could measure how different infrared wavelengths alter specific Marcus crossing configurations in isolated mitochondrial complexes, or track real-time changes in reorganization energy using advanced spectroscopy.

If validated, the implications extend far beyond biology. Urban planning, architecture, workplace design, and lighting standards may all need reconsideration.

Seheult introduces a new term: photometabolism—solar-driven, non-photosynthetic modulation of core metabolic processes.

It’s a concept that positions sunlight not as a passive environmental factor, but as an active participant in the biochemistry of life itself.

I believe that this hypothesis if true has major implications for the built environment and how we live and the type of light that we require to live, and I believe it’s one of the major reasons why we need to be treating our patients outside.

Sources

• Jeffery et al. (2025) – Longer wavelengths in sunlight penetrating human tissue
• Ma et al. (2018) – Infrared perturbation of charge separation and recombination
• Sanderson et al. (2018) – Inhibitory modulation of cytochrome c oxidase with near-infrared wavelengths
• Dai et al. (2026) – Infrared stimulation of mitochondrial metabolism in deep-sea yeast
• Hayashi et al. (2010) – Water-mediated electron transfer in iron-sulfur bridges
• Marcus and Sutin (1985) – Electron transfer reactions in chemistry

IR excitation increases the probability of donor and acceptor energies to remain in degeneracy, resulting in IR-induced electron transfer rate enhancement.

Seheult notes he and co-author Dr. Robert Fosbury spoke with Marcus himself—just months before the scientist passed away at age 102—to discuss their hypothesis.

Deep-Sea Yeast Thrives on Infrared Light—Without Photosynthesis

Perhaps the most striking evidence comes from an unexpected source: yeast living near hydrothermal vents at the bottom of the ocean.

A 2026 study by Dai and colleagues isolated yeast from sediments near a “black smoker” chimney in the central Indian Ocean, more than half a meter from superheated mineral plumes reaching 378°C.

When researchers exposed these yeast cultures to near-infrared light (810–1050 nm) in temperature-controlled conditions, growth increased dramatically compared to dark controls—even though the yeast cannot photosynthesize.

Infrared light outperformed glucose. Adding glucose increased biomass by only 1.3-fold (not statistically significant), while 880-nanometer infrared light produced a threefold increase.

When researchers blocked cytochrome c oxidase (complex IV in mitochondria), near-infrared-stimulated growth dropped by 44%—suggesting the effect operates directly on mitochondrial machinery.

Cold Temperatures, Warm Light

Even more remarkable: infrared light allowed yeast to grow at cooler temperatures where dark controls remained dormant.

At 20°C, yeast exposed to 880-nanometer light grew vigorously while dark controls showed minimal activity. The effective activation energy dropped from 12 kilocalories per mole to just 2 kilocalories per mole.

Infrared light was making up for the cold temperatures by supplying vibrational activation rather than thermal activation.

Proteomics revealed the most upregulated protein after infrared exposure was a mitochondrial ribosomal protein (MRPs8), increased 6.7-fold.

Why Broadband Sunlight May Beat Monochromatic LEDs

Clinical studies using single-wavelength infrared devices have shown benefits—from reducing ICU length of stay to improving muscle strength in COVID-19 patients.

But Seheult’s hypothesis suggests broadband infrared from the sun may be even more effective.

“Sunlight contains a broad spectrum of wavelengths that can interact with many different vibrational modes and electron transfer steps,” he explains, “rather than targeting only one narrow pathway.”

Research from Jeffery’s lab supports this. When comparing monochromatic 850-nanometer light to a 60-watt incandescent bulb (which emits broad-spectrum infrared), the incandescent bulb produced greater improvements in color blindness.

• Monochromatic 850 nm: 9% improvement (head and body), 5% (body only)
• 60W incandescent bulb: 28% improvement, sustained for weeks

The research here aligns with the hypothesis, though direct mechanistic proof in human mitochondria remains to be demonstrated.

The Modern Indoor Environment: A Metabolic Desert?

LED bulbs emit virtually no infrared radiation. Low-emissivity (Low-E) glass windows, designed to improve energy efficiency, block infrared wavelengths.

Seheult measured infrared exposure in his own dining room with windows open: 0.8 watts per square meter.

Step outside under a shade tree with grass reflecting sunlight? 41.9 watts per square meter—more than 50 times higher.

We have set up a situation where outdoors we’re getting plenty of infrared light, versus being indoors where we have Low-E glass blocking it and LED bulbs producing none.

This raises profound questions about whether chronic infrared deficiency could contribute to the rising burden of metabolic diseases, especially among populations spending most of their time indoors.

Seasonal Mortality Patterns Point to Sunlight’s Role

Death rates from heart disease, cancer, stroke, Alzheimer’s, diabetes, and respiratory illness all peak one to three weeks after the shortest day of the year and bottom out after the longest day.

This pattern holds across both infectious and non-infectious causes. The seasonal variation in heart disease deaths alone exceeds total influenza deaths during flu season.

Australia shows the same pattern, but shifted six months—deaths peak in July, their winter. Singapore, 80 miles from the equator with year-round sun, shows no seasonal mortality pattern.

Multiple studies have linked mortality rates to latitude, independent of vitamin D levels, suggesting sunlight itself—particularly its infrared component—plays a direct metabolic role.

Hospitals Are Bringing Patients Outside

Armed with mounting evidence, hospitals worldwide are redesigning care spaces to maximize sunlight exposure.

A $1.5 billion hospital in Footscray, Australia, built ICU beds with direct outdoor access. King’s College Hospital in London invested £2 million to transform its rooftop into a critical care garden where up to six ICU patients can receive treatment surrounded by greenery and natural light.

St. George’s Hospital in London followed suit, creating a neurointensive care rooftop unit. Queen Camilla visited the facility in 2026 to recognize the innovation.

Randomized controlled trials using infrared vests delivering roughly 20–30 watts per square meter (comparable to sitting under a tree) showed 30% reductions in ICU length of stay and improved muscle strength in critically ill COVID-19 patients.

Metabolic Scaling Matches Solar Power Scaling

One of the paper’s most intriguing observations: metabolic rate scales with body mass to the 3/4 power across species from flies to elephants.

Solar power intercepted by an organism also scales to the 3/4 power of mass—nearly identical.

This doesn’t prove causation, but it suggests sunlight could be a universal regulator of metabolic activity across the biosphere, with mitochondria in all organisms tuned to respond to the same infrared wavelengths present in Earth’s solar photon field.

What Makes This Hypothesis Different

Earlier theories proposed infrared light works by activating a photoreceptor in cytochrome c oxidase (complex IV) or by reducing water viscosity around ATP synthase motors.

Seheult’s team doesn’t reject these mechanisms—but argues they’re incomplete.

The Marcus framework explains phenomena earlier models couldn’t: why some infrared wavelengths inhibit rather than enhance mitochondrial activity, why broadband light outperforms monochromatic sources, and why effects persist across vastly different organisms.

The paper is the first to integrate four separate literature streams:

• Mitochondrial electron transfer follows Marcus physics
• Red and near-infrared light alter mitochondrial function
• Water and protein structures affect electron transfer kinetics
• Infrared radiation changes molecular electron transfer rates

“The novelty lies in the mechanistic integration,” Seheult emphasizes, “not in any single component.”

What Comes Next

The hypothesis is testable. Future experiments could measure how different infrared wavelengths alter specific Marcus crossing configurations in isolated mitochondrial complexes, or track real-time changes in reorganization energy using advanced spectroscopy.

If validated, the implications extend far beyond biology. Urban planning, architecture, workplace design, and lighting standards may all need reconsideration.

Seheult introduces a new term: photometabolism—solar-driven, non-photosynthetic modulation of core metabolic processes.

It’s a concept that positions sunlight not as a passive environmental factor, but as an active participant in the biochemistry of life itself.

I believe that this hypothesis if true has major implications for the built environment and how we live and the type of light that we require to live, and I believe it’s one of the major reasons why we need to be treating our patients outside.

Sources

• Jeffery et al. (2025) – Longer wavelengths in sunlight penetrating human tissue
• Ma et al. (2018) – Infrared perturbation of charge separation and recombination
• Sanderson et al. (2018) – Inhibitory modulation of cytochrome c oxidase with near-infrared wavelengths
• Dai et al. (2026) – Infrared stimulation of mitochondrial metabolism in deep-sea yeast
• Hayashi et al. (2010) – Water-mediated electron transfer in iron-sulfur bridges
• Marcus and Sutin (1985) – Electron transfer reactions in chemistry

They found infrared light slowed forward electron transfer but accelerated backward transfer—precisely what Marcus theory predicts when nuclear orientations are shifted along energy curves.

IR excitation increases the probability of donor and acceptor energies to remain in degeneracy, resulting in IR-induced electron transfer rate enhancement.

Seheult notes he and co-author Dr. Robert Fosbury spoke with Marcus himself—just months before the scientist passed away at age 102—to discuss their hypothesis.

Deep-Sea Yeast Thrives on Infrared Light—Without Photosynthesis

Perhaps the most striking evidence comes from an unexpected source: yeast living near hydrothermal vents at the bottom of the ocean.

A 2026 study by Dai and colleagues isolated yeast from sediments near a “black smoker” chimney in the central Indian Ocean, more than half a meter from superheated mineral plumes reaching 378°C.

When researchers exposed these yeast cultures to near-infrared light (810–1050 nm) in temperature-controlled conditions, growth increased dramatically compared to dark controls—even though the yeast cannot photosynthesize.

Infrared light outperformed glucose. Adding glucose increased biomass by only 1.3-fold (not statistically significant), while 880-nanometer infrared light produced a threefold increase.

When researchers blocked cytochrome c oxidase (complex IV in mitochondria), near-infrared-stimulated growth dropped by 44%—suggesting the effect operates directly on mitochondrial machinery.

Cold Temperatures, Warm Light

Even more remarkable: infrared light allowed yeast to grow at cooler temperatures where dark controls remained dormant.

At 20°C, yeast exposed to 880-nanometer light grew vigorously while dark controls showed minimal activity. The effective activation energy dropped from 12 kilocalories per mole to just 2 kilocalories per mole.

Infrared light was making up for the cold temperatures by supplying vibrational activation rather than thermal activation.

Proteomics revealed the most upregulated protein after infrared exposure was a mitochondrial ribosomal protein (MRPs8), increased 6.7-fold.

Why Broadband Sunlight May Beat Monochromatic LEDs

Clinical studies using single-wavelength infrared devices have shown benefits—from reducing ICU length of stay to improving muscle strength in COVID-19 patients.

But Seheult’s hypothesis suggests broadband infrared from the sun may be even more effective.

“Sunlight contains a broad spectrum of wavelengths that can interact with many different vibrational modes and electron transfer steps,” he explains, “rather than targeting only one narrow pathway.”

Research from Jeffery’s lab supports this. When comparing monochromatic 850-nanometer light to a 60-watt incandescent bulb (which emits broad-spectrum infrared), the incandescent bulb produced greater improvements in color blindness.

• Monochromatic 850 nm: 9% improvement (head and body), 5% (body only)
• 60W incandescent bulb: 28% improvement, sustained for weeks

The research here aligns with the hypothesis, though direct mechanistic proof in human mitochondria remains to be demonstrated.

The Modern Indoor Environment: A Metabolic Desert?

LED bulbs emit virtually no infrared radiation. Low-emissivity (Low-E) glass windows, designed to improve energy efficiency, block infrared wavelengths.

Seheult measured infrared exposure in his own dining room with windows open: 0.8 watts per square meter.

Step outside under a shade tree with grass reflecting sunlight? 41.9 watts per square meter—more than 50 times higher.

We have set up a situation where outdoors we’re getting plenty of infrared light, versus being indoors where we have Low-E glass blocking it and LED bulbs producing none.

This raises profound questions about whether chronic infrared deficiency could contribute to the rising burden of metabolic diseases, especially among populations spending most of their time indoors.

Seasonal Mortality Patterns Point to Sunlight’s Role

Death rates from heart disease, cancer, stroke, Alzheimer’s, diabetes, and respiratory illness all peak one to three weeks after the shortest day of the year and bottom out after the longest day.

This pattern holds across both infectious and non-infectious causes. The seasonal variation in heart disease deaths alone exceeds total influenza deaths during flu season.

Australia shows the same pattern, but shifted six months—deaths peak in July, their winter. Singapore, 80 miles from the equator with year-round sun, shows no seasonal mortality pattern.

Multiple studies have linked mortality rates to latitude, independent of vitamin D levels, suggesting sunlight itself—particularly its infrared component—plays a direct metabolic role.

Hospitals Are Bringing Patients Outside

Armed with mounting evidence, hospitals worldwide are redesigning care spaces to maximize sunlight exposure.

A $1.5 billion hospital in Footscray, Australia, built ICU beds with direct outdoor access. King’s College Hospital in London invested £2 million to transform its rooftop into a critical care garden where up to six ICU patients can receive treatment surrounded by greenery and natural light.

St. George’s Hospital in London followed suit, creating a neurointensive care rooftop unit. Queen Camilla visited the facility in 2026 to recognize the innovation.

Randomized controlled trials using infrared vests delivering roughly 20–30 watts per square meter (comparable to sitting under a tree) showed 30% reductions in ICU length of stay and improved muscle strength in critically ill COVID-19 patients.

Metabolic Scaling Matches Solar Power Scaling

One of the paper’s most intriguing observations: metabolic rate scales with body mass to the 3/4 power across species from flies to elephants.

Solar power intercepted by an organism also scales to the 3/4 power of mass—nearly identical.

This doesn’t prove causation, but it suggests sunlight could be a universal regulator of metabolic activity across the biosphere, with mitochondria in all organisms tuned to respond to the same infrared wavelengths present in Earth’s solar photon field.

What Makes This Hypothesis Different

Earlier theories proposed infrared light works by activating a photoreceptor in cytochrome c oxidase (complex IV) or by reducing water viscosity around ATP synthase motors.

Seheult’s team doesn’t reject these mechanisms—but argues they’re incomplete.

The Marcus framework explains phenomena earlier models couldn’t: why some infrared wavelengths inhibit rather than enhance mitochondrial activity, why broadband light outperforms monochromatic sources, and why effects persist across vastly different organisms.

The paper is the first to integrate four separate literature streams:

• Mitochondrial electron transfer follows Marcus physics
• Red and near-infrared light alter mitochondrial function
• Water and protein structures affect electron transfer kinetics
• Infrared radiation changes molecular electron transfer rates

“The novelty lies in the mechanistic integration,” Seheult emphasizes, “not in any single component.”

What Comes Next

The hypothesis is testable. Future experiments could measure how different infrared wavelengths alter specific Marcus crossing configurations in isolated mitochondrial complexes, or track real-time changes in reorganization energy using advanced spectroscopy.

If validated, the implications extend far beyond biology. Urban planning, architecture, workplace design, and lighting standards may all need reconsideration.

Seheult introduces a new term: photometabolism—solar-driven, non-photosynthetic modulation of core metabolic processes.

It’s a concept that positions sunlight not as a passive environmental factor, but as an active participant in the biochemistry of life itself.

I believe that this hypothesis if true has major implications for the built environment and how we live and the type of light that we require to live, and I believe it’s one of the major reasons why we need to be treating our patients outside.

Sources

• Jeffery et al. (2025) – Longer wavelengths in sunlight penetrating human tissue
• Ma et al. (2018) – Infrared perturbation of charge separation and recombination
• Sanderson et al. (2018) – Inhibitory modulation of cytochrome c oxidase with near-infrared wavelengths
• Dai et al. (2026) – Infrared stimulation of mitochondrial metabolism in deep-sea yeast
• Hayashi et al. (2010) – Water-mediated electron transfer in iron-sulfur bridges
• Marcus and Sutin (1985) – Electron transfer reactions in chemistry

They found infrared light slowed forward electron transfer but accelerated backward transfer—precisely what Marcus theory predicts when nuclear orientations are shifted along energy curves.

IR excitation increases the probability of donor and acceptor energies to remain in degeneracy, resulting in IR-induced electron transfer rate enhancement.

Seheult notes he and co-author Dr. Robert Fosbury spoke with Marcus himself—just months before the scientist passed away at age 102—to discuss their hypothesis.

Deep-Sea Yeast Thrives on Infrared Light—Without Photosynthesis

Perhaps the most striking evidence comes from an unexpected source: yeast living near hydrothermal vents at the bottom of the ocean.

A 2026 study by Dai and colleagues isolated yeast from sediments near a “black smoker” chimney in the central Indian Ocean, more than half a meter from superheated mineral plumes reaching 378°C.

When researchers exposed these yeast cultures to near-infrared light (810–1050 nm) in temperature-controlled conditions, growth increased dramatically compared to dark controls—even though the yeast cannot photosynthesize.

Infrared light outperformed glucose. Adding glucose increased biomass by only 1.3-fold (not statistically significant), while 880-nanometer infrared light produced a threefold increase.

When researchers blocked cytochrome c oxidase (complex IV in mitochondria), near-infrared-stimulated growth dropped by 44%—suggesting the effect operates directly on mitochondrial machinery.

Cold Temperatures, Warm Light

Even more remarkable: infrared light allowed yeast to grow at cooler temperatures where dark controls remained dormant.

At 20°C, yeast exposed to 880-nanometer light grew vigorously while dark controls showed minimal activity. The effective activation energy dropped from 12 kilocalories per mole to just 2 kilocalories per mole.

Infrared light was making up for the cold temperatures by supplying vibrational activation rather than thermal activation.

Proteomics revealed the most upregulated protein after infrared exposure was a mitochondrial ribosomal protein (MRPs8), increased 6.7-fold.

Why Broadband Sunlight May Beat Monochromatic LEDs

Clinical studies using single-wavelength infrared devices have shown benefits—from reducing ICU length of stay to improving muscle strength in COVID-19 patients.

But Seheult’s hypothesis suggests broadband infrared from the sun may be even more effective.

“Sunlight contains a broad spectrum of wavelengths that can interact with many different vibrational modes and electron transfer steps,” he explains, “rather than targeting only one narrow pathway.”

Research from Jeffery’s lab supports this. When comparing monochromatic 850-nanometer light to a 60-watt incandescent bulb (which emits broad-spectrum infrared), the incandescent bulb produced greater improvements in color blindness.

• Monochromatic 850 nm: 9% improvement (head and body), 5% (body only)
• 60W incandescent bulb: 28% improvement, sustained for weeks

The research here aligns with the hypothesis, though direct mechanistic proof in human mitochondria remains to be demonstrated.

The Modern Indoor Environment: A Metabolic Desert?

LED bulbs emit virtually no infrared radiation. Low-emissivity (Low-E) glass windows, designed to improve energy efficiency, block infrared wavelengths.

Seheult measured infrared exposure in his own dining room with windows open: 0.8 watts per square meter.

Step outside under a shade tree with grass reflecting sunlight? 41.9 watts per square meter—more than 50 times higher.

We have set up a situation where outdoors we’re getting plenty of infrared light, versus being indoors where we have Low-E glass blocking it and LED bulbs producing none.

This raises profound questions about whether chronic infrared deficiency could contribute to the rising burden of metabolic diseases, especially among populations spending most of their time indoors.

Seasonal Mortality Patterns Point to Sunlight’s Role

Death rates from heart disease, cancer, stroke, Alzheimer’s, diabetes, and respiratory illness all peak one to three weeks after the shortest day of the year and bottom out after the longest day.

This pattern holds across both infectious and non-infectious causes. The seasonal variation in heart disease deaths alone exceeds total influenza deaths during flu season.

Australia shows the same pattern, but shifted six months—deaths peak in July, their winter. Singapore, 80 miles from the equator with year-round sun, shows no seasonal mortality pattern.

Multiple studies have linked mortality rates to latitude, independent of vitamin D levels, suggesting sunlight itself—particularly its infrared component—plays a direct metabolic role.

Hospitals Are Bringing Patients Outside

Armed with mounting evidence, hospitals worldwide are redesigning care spaces to maximize sunlight exposure.

A $1.5 billion hospital in Footscray, Australia, built ICU beds with direct outdoor access. King’s College Hospital in London invested £2 million to transform its rooftop into a critical care garden where up to six ICU patients can receive treatment surrounded by greenery and natural light.

St. George’s Hospital in London followed suit, creating a neurointensive care rooftop unit. Queen Camilla visited the facility in 2026 to recognize the innovation.

Randomized controlled trials using infrared vests delivering roughly 20–30 watts per square meter (comparable to sitting under a tree) showed 30% reductions in ICU length of stay and improved muscle strength in critically ill COVID-19 patients.

Metabolic Scaling Matches Solar Power Scaling

One of the paper’s most intriguing observations: metabolic rate scales with body mass to the 3/4 power across species from flies to elephants.

Solar power intercepted by an organism also scales to the 3/4 power of mass—nearly identical.

This doesn’t prove causation, but it suggests sunlight could be a universal regulator of metabolic activity across the biosphere, with mitochondria in all organisms tuned to respond to the same infrared wavelengths present in Earth’s solar photon field.

What Makes This Hypothesis Different

Earlier theories proposed infrared light works by activating a photoreceptor in cytochrome c oxidase (complex IV) or by reducing water viscosity around ATP synthase motors.

Seheult’s team doesn’t reject these mechanisms—but argues they’re incomplete.

The Marcus framework explains phenomena earlier models couldn’t: why some infrared wavelengths inhibit rather than enhance mitochondrial activity, why broadband light outperforms monochromatic sources, and why effects persist across vastly different organisms.

The paper is the first to integrate four separate literature streams:

• Mitochondrial electron transfer follows Marcus physics
• Red and near-infrared light alter mitochondrial function
• Water and protein structures affect electron transfer kinetics
• Infrared radiation changes molecular electron transfer rates

“The novelty lies in the mechanistic integration,” Seheult emphasizes, “not in any single component.”

What Comes Next

The hypothesis is testable. Future experiments could measure how different infrared wavelengths alter specific Marcus crossing configurations in isolated mitochondrial complexes, or track real-time changes in reorganization energy using advanced spectroscopy.

If validated, the implications extend far beyond biology. Urban planning, architecture, workplace design, and lighting standards may all need reconsideration.

Seheult introduces a new term: photometabolism—solar-driven, non-photosynthetic modulation of core metabolic processes.

It’s a concept that positions sunlight not as a passive environmental factor, but as an active participant in the biochemistry of life itself.

I believe that this hypothesis if true has major implications for the built environment and how we live and the type of light that we require to live, and I believe it’s one of the major reasons why we need to be treating our patients outside.

Sources

• Jeffery et al. (2025) – Longer wavelengths in sunlight penetrating human tissue
• Ma et al. (2018) – Infrared perturbation of charge separation and recombination
• Sanderson et al. (2018) – Inhibitory modulation of cytochrome c oxidase with near-infrared wavelengths
• Dai et al. (2026) – Infrared stimulation of mitochondrial metabolism in deep-sea yeast
• Hayashi et al. (2010) – Water-mediated electron transfer in iron-sulfur bridges
• Marcus and Sutin (1985) – Electron transfer reactions in chemistry

A 2018 study by Ma and colleagues tested this exact principle. Researchers built a custom molecule and used mid-infrared light to excite vibrational modes.

They found infrared light slowed forward electron transfer but accelerated backward transfer—precisely what Marcus theory predicts when nuclear orientations are shifted along energy curves.

IR excitation increases the probability of donor and acceptor energies to remain in degeneracy, resulting in IR-induced electron transfer rate enhancement.

Seheult notes he and co-author Dr. Robert Fosbury spoke with Marcus himself—just months before the scientist passed away at age 102—to discuss their hypothesis.

Deep-Sea Yeast Thrives on Infrared Light—Without Photosynthesis

Perhaps the most striking evidence comes from an unexpected source: yeast living near hydrothermal vents at the bottom of the ocean.

A 2026 study by Dai and colleagues isolated yeast from sediments near a “black smoker” chimney in the central Indian Ocean, more than half a meter from superheated mineral plumes reaching 378°C.

When researchers exposed these yeast cultures to near-infrared light (810–1050 nm) in temperature-controlled conditions, growth increased dramatically compared to dark controls—even though the yeast cannot photosynthesize.

Infrared light outperformed glucose. Adding glucose increased biomass by only 1.3-fold (not statistically significant), while 880-nanometer infrared light produced a threefold increase.

When researchers blocked cytochrome c oxidase (complex IV in mitochondria), near-infrared-stimulated growth dropped by 44%—suggesting the effect operates directly on mitochondrial machinery.

Cold Temperatures, Warm Light

Even more remarkable: infrared light allowed yeast to grow at cooler temperatures where dark controls remained dormant.

At 20°C, yeast exposed to 880-nanometer light grew vigorously while dark controls showed minimal activity. The effective activation energy dropped from 12 kilocalories per mole to just 2 kilocalories per mole.

Infrared light was making up for the cold temperatures by supplying vibrational activation rather than thermal activation.

Proteomics revealed the most upregulated protein after infrared exposure was a mitochondrial ribosomal protein (MRPs8), increased 6.7-fold.

Why Broadband Sunlight May Beat Monochromatic LEDs

Clinical studies using single-wavelength infrared devices have shown benefits—from reducing ICU length of stay to improving muscle strength in COVID-19 patients.

But Seheult’s hypothesis suggests broadband infrared from the sun may be even more effective.

“Sunlight contains a broad spectrum of wavelengths that can interact with many different vibrational modes and electron transfer steps,” he explains, “rather than targeting only one narrow pathway.”

Research from Jeffery’s lab supports this. When comparing monochromatic 850-nanometer light to a 60-watt incandescent bulb (which emits broad-spectrum infrared), the incandescent bulb produced greater improvements in color blindness.

• Monochromatic 850 nm: 9% improvement (head and body), 5% (body only)
• 60W incandescent bulb: 28% improvement, sustained for weeks

The research here aligns with the hypothesis, though direct mechanistic proof in human mitochondria remains to be demonstrated.

The Modern Indoor Environment: A Metabolic Desert?

LED bulbs emit virtually no infrared radiation. Low-emissivity (Low-E) glass windows, designed to improve energy efficiency, block infrared wavelengths.

Seheult measured infrared exposure in his own dining room with windows open: 0.8 watts per square meter.

Step outside under a shade tree with grass reflecting sunlight? 41.9 watts per square meter—more than 50 times higher.

We have set up a situation where outdoors we’re getting plenty of infrared light, versus being indoors where we have Low-E glass blocking it and LED bulbs producing none.

This raises profound questions about whether chronic infrared deficiency could contribute to the rising burden of metabolic diseases, especially among populations spending most of their time indoors.

Seasonal Mortality Patterns Point to Sunlight’s Role

Death rates from heart disease, cancer, stroke, Alzheimer’s, diabetes, and respiratory illness all peak one to three weeks after the shortest day of the year and bottom out after the longest day.

This pattern holds across both infectious and non-infectious causes. The seasonal variation in heart disease deaths alone exceeds total influenza deaths during flu season.

Australia shows the same pattern, but shifted six months—deaths peak in July, their winter. Singapore, 80 miles from the equator with year-round sun, shows no seasonal mortality pattern.

Multiple studies have linked mortality rates to latitude, independent of vitamin D levels, suggesting sunlight itself—particularly its infrared component—plays a direct metabolic role.

Hospitals Are Bringing Patients Outside

Armed with mounting evidence, hospitals worldwide are redesigning care spaces to maximize sunlight exposure.

A $1.5 billion hospital in Footscray, Australia, built ICU beds with direct outdoor access. King’s College Hospital in London invested £2 million to transform its rooftop into a critical care garden where up to six ICU patients can receive treatment surrounded by greenery and natural light.

St. George’s Hospital in London followed suit, creating a neurointensive care rooftop unit. Queen Camilla visited the facility in 2026 to recognize the innovation.

Randomized controlled trials using infrared vests delivering roughly 20–30 watts per square meter (comparable to sitting under a tree) showed 30% reductions in ICU length of stay and improved muscle strength in critically ill COVID-19 patients.

Metabolic Scaling Matches Solar Power Scaling

One of the paper’s most intriguing observations: metabolic rate scales with body mass to the 3/4 power across species from flies to elephants.

Solar power intercepted by an organism also scales to the 3/4 power of mass—nearly identical.

This doesn’t prove causation, but it suggests sunlight could be a universal regulator of metabolic activity across the biosphere, with mitochondria in all organisms tuned to respond to the same infrared wavelengths present in Earth’s solar photon field.

What Makes This Hypothesis Different

Earlier theories proposed infrared light works by activating a photoreceptor in cytochrome c oxidase (complex IV) or by reducing water viscosity around ATP synthase motors.

Seheult’s team doesn’t reject these mechanisms—but argues they’re incomplete.

The Marcus framework explains phenomena earlier models couldn’t: why some infrared wavelengths inhibit rather than enhance mitochondrial activity, why broadband light outperforms monochromatic sources, and why effects persist across vastly different organisms.

The paper is the first to integrate four separate literature streams:

• Mitochondrial electron transfer follows Marcus physics
• Red and near-infrared light alter mitochondrial function
• Water and protein structures affect electron transfer kinetics
• Infrared radiation changes molecular electron transfer rates

“The novelty lies in the mechanistic integration,” Seheult emphasizes, “not in any single component.”

What Comes Next

The hypothesis is testable. Future experiments could measure how different infrared wavelengths alter specific Marcus crossing configurations in isolated mitochondrial complexes, or track real-time changes in reorganization energy using advanced spectroscopy.

If validated, the implications extend far beyond biology. Urban planning, architecture, workplace design, and lighting standards may all need reconsideration.

Seheult introduces a new term: photometabolism—solar-driven, non-photosynthetic modulation of core metabolic processes.

It’s a concept that positions sunlight not as a passive environmental factor, but as an active participant in the biochemistry of life itself.

I believe that this hypothesis if true has major implications for the built environment and how we live and the type of light that we require to live, and I believe it’s one of the major reasons why we need to be treating our patients outside.

Sources

• Jeffery et al. (2025) – Longer wavelengths in sunlight penetrating human tissue
• Ma et al. (2018) – Infrared perturbation of charge separation and recombination
• Sanderson et al. (2018) – Inhibitory modulation of cytochrome c oxidase with near-infrared wavelengths
• Dai et al. (2026) – Infrared stimulation of mitochondrial metabolism in deep-sea yeast
• Hayashi et al. (2010) – Water-mediated electron transfer in iron-sulfur bridges
• Marcus and Sutin (1985) – Electron transfer reactions in chemistry

A 2018 study by Ma and colleagues tested this exact principle. Researchers built a custom molecule and used mid-infrared light to excite vibrational modes.

They found infrared light slowed forward electron transfer but accelerated backward transfer—precisely what Marcus theory predicts when nuclear orientations are shifted along energy curves.

IR excitation increases the probability of donor and acceptor energies to remain in degeneracy, resulting in IR-induced electron transfer rate enhancement.

Seheult notes he and co-author Dr. Robert Fosbury spoke with Marcus himself—just months before the scientist passed away at age 102—to discuss their hypothesis.

Deep-Sea Yeast Thrives on Infrared Light—Without Photosynthesis

Perhaps the most striking evidence comes from an unexpected source: yeast living near hydrothermal vents at the bottom of the ocean.

A 2026 study by Dai and colleagues isolated yeast from sediments near a “black smoker” chimney in the central Indian Ocean, more than half a meter from superheated mineral plumes reaching 378°C.

When researchers exposed these yeast cultures to near-infrared light (810–1050 nm) in temperature-controlled conditions, growth increased dramatically compared to dark controls—even though the yeast cannot photosynthesize.

Infrared light outperformed glucose. Adding glucose increased biomass by only 1.3-fold (not statistically significant), while 880-nanometer infrared light produced a threefold increase.

When researchers blocked cytochrome c oxidase (complex IV in mitochondria), near-infrared-stimulated growth dropped by 44%—suggesting the effect operates directly on mitochondrial machinery.

Cold Temperatures, Warm Light

Even more remarkable: infrared light allowed yeast to grow at cooler temperatures where dark controls remained dormant.

At 20°C, yeast exposed to 880-nanometer light grew vigorously while dark controls showed minimal activity. The effective activation energy dropped from 12 kilocalories per mole to just 2 kilocalories per mole.

Infrared light was making up for the cold temperatures by supplying vibrational activation rather than thermal activation.

Proteomics revealed the most upregulated protein after infrared exposure was a mitochondrial ribosomal protein (MRPs8), increased 6.7-fold.

Why Broadband Sunlight May Beat Monochromatic LEDs

Clinical studies using single-wavelength infrared devices have shown benefits—from reducing ICU length of stay to improving muscle strength in COVID-19 patients.

But Seheult’s hypothesis suggests broadband infrared from the sun may be even more effective.

“Sunlight contains a broad spectrum of wavelengths that can interact with many different vibrational modes and electron transfer steps,” he explains, “rather than targeting only one narrow pathway.”

Research from Jeffery’s lab supports this. When comparing monochromatic 850-nanometer light to a 60-watt incandescent bulb (which emits broad-spectrum infrared), the incandescent bulb produced greater improvements in color blindness.

• Monochromatic 850 nm: 9% improvement (head and body), 5% (body only)
• 60W incandescent bulb: 28% improvement, sustained for weeks

The research here aligns with the hypothesis, though direct mechanistic proof in human mitochondria remains to be demonstrated.

The Modern Indoor Environment: A Metabolic Desert?

LED bulbs emit virtually no infrared radiation. Low-emissivity (Low-E) glass windows, designed to improve energy efficiency, block infrared wavelengths.

Seheult measured infrared exposure in his own dining room with windows open: 0.8 watts per square meter.

Step outside under a shade tree with grass reflecting sunlight? 41.9 watts per square meter—more than 50 times higher.

We have set up a situation where outdoors we’re getting plenty of infrared light, versus being indoors where we have Low-E glass blocking it and LED bulbs producing none.

This raises profound questions about whether chronic infrared deficiency could contribute to the rising burden of metabolic diseases, especially among populations spending most of their time indoors.

Seasonal Mortality Patterns Point to Sunlight’s Role

Death rates from heart disease, cancer, stroke, Alzheimer’s, diabetes, and respiratory illness all peak one to three weeks after the shortest day of the year and bottom out after the longest day.

This pattern holds across both infectious and non-infectious causes. The seasonal variation in heart disease deaths alone exceeds total influenza deaths during flu season.

Australia shows the same pattern, but shifted six months—deaths peak in July, their winter. Singapore, 80 miles from the equator with year-round sun, shows no seasonal mortality pattern.

Multiple studies have linked mortality rates to latitude, independent of vitamin D levels, suggesting sunlight itself—particularly its infrared component—plays a direct metabolic role.

Hospitals Are Bringing Patients Outside

Armed with mounting evidence, hospitals worldwide are redesigning care spaces to maximize sunlight exposure.

A $1.5 billion hospital in Footscray, Australia, built ICU beds with direct outdoor access. King’s College Hospital in London invested £2 million to transform its rooftop into a critical care garden where up to six ICU patients can receive treatment surrounded by greenery and natural light.

St. George’s Hospital in London followed suit, creating a neurointensive care rooftop unit. Queen Camilla visited the facility in 2026 to recognize the innovation.

Randomized controlled trials using infrared vests delivering roughly 20–30 watts per square meter (comparable to sitting under a tree) showed 30% reductions in ICU length of stay and improved muscle strength in critically ill COVID-19 patients.

Metabolic Scaling Matches Solar Power Scaling

One of the paper’s most intriguing observations: metabolic rate scales with body mass to the 3/4 power across species from flies to elephants.

Solar power intercepted by an organism also scales to the 3/4 power of mass—nearly identical.

This doesn’t prove causation, but it suggests sunlight could be a universal regulator of metabolic activity across the biosphere, with mitochondria in all organisms tuned to respond to the same infrared wavelengths present in Earth’s solar photon field.

What Makes This Hypothesis Different

Earlier theories proposed infrared light works by activating a photoreceptor in cytochrome c oxidase (complex IV) or by reducing water viscosity around ATP synthase motors.

Seheult’s team doesn’t reject these mechanisms—but argues they’re incomplete.

The Marcus framework explains phenomena earlier models couldn’t: why some infrared wavelengths inhibit rather than enhance mitochondrial activity, why broadband light outperforms monochromatic sources, and why effects persist across vastly different organisms.

The paper is the first to integrate four separate literature streams:

• Mitochondrial electron transfer follows Marcus physics
• Red and near-infrared light alter mitochondrial function
• Water and protein structures affect electron transfer kinetics
• Infrared radiation changes molecular electron transfer rates

“The novelty lies in the mechanistic integration,” Seheult emphasizes, “not in any single component.”

What Comes Next

The hypothesis is testable. Future experiments could measure how different infrared wavelengths alter specific Marcus crossing configurations in isolated mitochondrial complexes, or track real-time changes in reorganization energy using advanced spectroscopy.

If validated, the implications extend far beyond biology. Urban planning, architecture, workplace design, and lighting standards may all need reconsideration.

Seheult introduces a new term: photometabolism—solar-driven, non-photosynthetic modulation of core metabolic processes.

It’s a concept that positions sunlight not as a passive environmental factor, but as an active participant in the biochemistry of life itself.

I believe that this hypothesis if true has major implications for the built environment and how we live and the type of light that we require to live, and I believe it’s one of the major reasons why we need to be treating our patients outside.

Sources

• Jeffery et al. (2025) – Longer wavelengths in sunlight penetrating human tissue
• Ma et al. (2018) – Infrared perturbation of charge separation and recombination
• Sanderson et al. (2018) – Inhibitory modulation of cytochrome c oxidase with near-infrared wavelengths
• Dai et al. (2026) – Infrared stimulation of mitochondrial metabolism in deep-sea yeast
• Hayashi et al. (2010) – Water-mediated electron transfer in iron-sulfur bridges
• Marcus and Sutin (1985) – Electron transfer reactions in chemistry

Experiments Confirm the Mechanism

A 2018 study by Ma and colleagues tested this exact principle. Researchers built a custom molecule and used mid-infrared light to excite vibrational modes.

They found infrared light slowed forward electron transfer but accelerated backward transfer—precisely what Marcus theory predicts when nuclear orientations are shifted along energy curves.

IR excitation increases the probability of donor and acceptor energies to remain in degeneracy, resulting in IR-induced electron transfer rate enhancement.

Seheult notes he and co-author Dr. Robert Fosbury spoke with Marcus himself—just months before the scientist passed away at age 102—to discuss their hypothesis.

Deep-Sea Yeast Thrives on Infrared Light—Without Photosynthesis

Perhaps the most striking evidence comes from an unexpected source: yeast living near hydrothermal vents at the bottom of the ocean.

A 2026 study by Dai and colleagues isolated yeast from sediments near a “black smoker” chimney in the central Indian Ocean, more than half a meter from superheated mineral plumes reaching 378°C.

When researchers exposed these yeast cultures to near-infrared light (810–1050 nm) in temperature-controlled conditions, growth increased dramatically compared to dark controls—even though the yeast cannot photosynthesize.

Infrared light outperformed glucose. Adding glucose increased biomass by only 1.3-fold (not statistically significant), while 880-nanometer infrared light produced a threefold increase.

When researchers blocked cytochrome c oxidase (complex IV in mitochondria), near-infrared-stimulated growth dropped by 44%—suggesting the effect operates directly on mitochondrial machinery.

Cold Temperatures, Warm Light

Even more remarkable: infrared light allowed yeast to grow at cooler temperatures where dark controls remained dormant.

At 20°C, yeast exposed to 880-nanometer light grew vigorously while dark controls showed minimal activity. The effective activation energy dropped from 12 kilocalories per mole to just 2 kilocalories per mole.

Infrared light was making up for the cold temperatures by supplying vibrational activation rather than thermal activation.

Proteomics revealed the most upregulated protein after infrared exposure was a mitochondrial ribosomal protein (MRPs8), increased 6.7-fold.

Why Broadband Sunlight May Beat Monochromatic LEDs

Clinical studies using single-wavelength infrared devices have shown benefits—from reducing ICU length of stay to improving muscle strength in COVID-19 patients.

But Seheult’s hypothesis suggests broadband infrared from the sun may be even more effective.

“Sunlight contains a broad spectrum of wavelengths that can interact with many different vibrational modes and electron transfer steps,” he explains, “rather than targeting only one narrow pathway.”

Research from Jeffery’s lab supports this. When comparing monochromatic 850-nanometer light to a 60-watt incandescent bulb (which emits broad-spectrum infrared), the incandescent bulb produced greater improvements in color blindness.

• Monochromatic 850 nm: 9% improvement (head and body), 5% (body only)
• 60W incandescent bulb: 28% improvement, sustained for weeks

The research here aligns with the hypothesis, though direct mechanistic proof in human mitochondria remains to be demonstrated.

The Modern Indoor Environment: A Metabolic Desert?

LED bulbs emit virtually no infrared radiation. Low-emissivity (Low-E) glass windows, designed to improve energy efficiency, block infrared wavelengths.

Seheult measured infrared exposure in his own dining room with windows open: 0.8 watts per square meter.

Step outside under a shade tree with grass reflecting sunlight? 41.9 watts per square meter—more than 50 times higher.

We have set up a situation where outdoors we’re getting plenty of infrared light, versus being indoors where we have Low-E glass blocking it and LED bulbs producing none.

This raises profound questions about whether chronic infrared deficiency could contribute to the rising burden of metabolic diseases, especially among populations spending most of their time indoors.

Seasonal Mortality Patterns Point to Sunlight’s Role

Death rates from heart disease, cancer, stroke, Alzheimer’s, diabetes, and respiratory illness all peak one to three weeks after the shortest day of the year and bottom out after the longest day.

This pattern holds across both infectious and non-infectious causes. The seasonal variation in heart disease deaths alone exceeds total influenza deaths during flu season.

Australia shows the same pattern, but shifted six months—deaths peak in July, their winter. Singapore, 80 miles from the equator with year-round sun, shows no seasonal mortality pattern.

Multiple studies have linked mortality rates to latitude, independent of vitamin D levels, suggesting sunlight itself—particularly its infrared component—plays a direct metabolic role.

Hospitals Are Bringing Patients Outside

Armed with mounting evidence, hospitals worldwide are redesigning care spaces to maximize sunlight exposure.

A $1.5 billion hospital in Footscray, Australia, built ICU beds with direct outdoor access. King’s College Hospital in London invested £2 million to transform its rooftop into a critical care garden where up to six ICU patients can receive treatment surrounded by greenery and natural light.

St. George’s Hospital in London followed suit, creating a neurointensive care rooftop unit. Queen Camilla visited the facility in 2026 to recognize the innovation.

Randomized controlled trials using infrared vests delivering roughly 20–30 watts per square meter (comparable to sitting under a tree) showed 30% reductions in ICU length of stay and improved muscle strength in critically ill COVID-19 patients.

Metabolic Scaling Matches Solar Power Scaling

One of the paper’s most intriguing observations: metabolic rate scales with body mass to the 3/4 power across species from flies to elephants.

Solar power intercepted by an organism also scales to the 3/4 power of mass—nearly identical.

This doesn’t prove causation, but it suggests sunlight could be a universal regulator of metabolic activity across the biosphere, with mitochondria in all organisms tuned to respond to the same infrared wavelengths present in Earth’s solar photon field.

What Makes This Hypothesis Different

Earlier theories proposed infrared light works by activating a photoreceptor in cytochrome c oxidase (complex IV) or by reducing water viscosity around ATP synthase motors.

Seheult’s team doesn’t reject these mechanisms—but argues they’re incomplete.

The Marcus framework explains phenomena earlier models couldn’t: why some infrared wavelengths inhibit rather than enhance mitochondrial activity, why broadband light outperforms monochromatic sources, and why effects persist across vastly different organisms.

The paper is the first to integrate four separate literature streams:

• Mitochondrial electron transfer follows Marcus physics
• Red and near-infrared light alter mitochondrial function
• Water and protein structures affect electron transfer kinetics
• Infrared radiation changes molecular electron transfer rates

“The novelty lies in the mechanistic integration,” Seheult emphasizes, “not in any single component.”

What Comes Next

The hypothesis is testable. Future experiments could measure how different infrared wavelengths alter specific Marcus crossing configurations in isolated mitochondrial complexes, or track real-time changes in reorganization energy using advanced spectroscopy.

If validated, the implications extend far beyond biology. Urban planning, architecture, workplace design, and lighting standards may all need reconsideration.

Seheult introduces a new term: photometabolism—solar-driven, non-photosynthetic modulation of core metabolic processes.

It’s a concept that positions sunlight not as a passive environmental factor, but as an active participant in the biochemistry of life itself.

I believe that this hypothesis if true has major implications for the built environment and how we live and the type of light that we require to live, and I believe it’s one of the major reasons why we need to be treating our patients outside.

Sources

• Jeffery et al. (2025) – Longer wavelengths in sunlight penetrating human tissue
• Ma et al. (2018) – Infrared perturbation of charge separation and recombination
• Sanderson et al. (2018) – Inhibitory modulation of cytochrome c oxidase with near-infrared wavelengths
• Dai et al. (2026) – Infrared stimulation of mitochondrial metabolism in deep-sea yeast
• Hayashi et al. (2010) – Water-mediated electron transfer in iron-sulfur bridges
• Marcus and Sutin (1985) – Electron transfer reactions in chemistry

Experiments Confirm the Mechanism

A 2018 study by Ma and colleagues tested this exact principle. Researchers built a custom molecule and used mid-infrared light to excite vibrational modes.

They found infrared light slowed forward electron transfer but accelerated backward transfer—precisely what Marcus theory predicts when nuclear orientations are shifted along energy curves.

IR excitation increases the probability of donor and acceptor energies to remain in degeneracy, resulting in IR-induced electron transfer rate enhancement.

Seheult notes he and co-author Dr. Robert Fosbury spoke with Marcus himself—just months before the scientist passed away at age 102—to discuss their hypothesis.

Deep-Sea Yeast Thrives on Infrared Light—Without Photosynthesis

Perhaps the most striking evidence comes from an unexpected source: yeast living near hydrothermal vents at the bottom of the ocean.

A 2026 study by Dai and colleagues isolated yeast from sediments near a “black smoker” chimney in the central Indian Ocean, more than half a meter from superheated mineral plumes reaching 378°C.

When researchers exposed these yeast cultures to near-infrared light (810–1050 nm) in temperature-controlled conditions, growth increased dramatically compared to dark controls—even though the yeast cannot photosynthesize.

Infrared light outperformed glucose. Adding glucose increased biomass by only 1.3-fold (not statistically significant), while 880-nanometer infrared light produced a threefold increase.

When researchers blocked cytochrome c oxidase (complex IV in mitochondria), near-infrared-stimulated growth dropped by 44%—suggesting the effect operates directly on mitochondrial machinery.

Cold Temperatures, Warm Light

Even more remarkable: infrared light allowed yeast to grow at cooler temperatures where dark controls remained dormant.

At 20°C, yeast exposed to 880-nanometer light grew vigorously while dark controls showed minimal activity. The effective activation energy dropped from 12 kilocalories per mole to just 2 kilocalories per mole.

Infrared light was making up for the cold temperatures by supplying vibrational activation rather than thermal activation.

Proteomics revealed the most upregulated protein after infrared exposure was a mitochondrial ribosomal protein (MRPs8), increased 6.7-fold.

Why Broadband Sunlight May Beat Monochromatic LEDs

Clinical studies using single-wavelength infrared devices have shown benefits—from reducing ICU length of stay to improving muscle strength in COVID-19 patients.

But Seheult’s hypothesis suggests broadband infrared from the sun may be even more effective.

“Sunlight contains a broad spectrum of wavelengths that can interact with many different vibrational modes and electron transfer steps,” he explains, “rather than targeting only one narrow pathway.”

Research from Jeffery’s lab supports this. When comparing monochromatic 850-nanometer light to a 60-watt incandescent bulb (which emits broad-spectrum infrared), the incandescent bulb produced greater improvements in color blindness.

• Monochromatic 850 nm: 9% improvement (head and body), 5% (body only)
• 60W incandescent bulb: 28% improvement, sustained for weeks

The research here aligns with the hypothesis, though direct mechanistic proof in human mitochondria remains to be demonstrated.

The Modern Indoor Environment: A Metabolic Desert?

LED bulbs emit virtually no infrared radiation. Low-emissivity (Low-E) glass windows, designed to improve energy efficiency, block infrared wavelengths.

Seheult measured infrared exposure in his own dining room with windows open: 0.8 watts per square meter.

Step outside under a shade tree with grass reflecting sunlight? 41.9 watts per square meter—more than 50 times higher.

We have set up a situation where outdoors we’re getting plenty of infrared light, versus being indoors where we have Low-E glass blocking it and LED bulbs producing none.

This raises profound questions about whether chronic infrared deficiency could contribute to the rising burden of metabolic diseases, especially among populations spending most of their time indoors.

Seasonal Mortality Patterns Point to Sunlight’s Role

Death rates from heart disease, cancer, stroke, Alzheimer’s, diabetes, and respiratory illness all peak one to three weeks after the shortest day of the year and bottom out after the longest day.

This pattern holds across both infectious and non-infectious causes. The seasonal variation in heart disease deaths alone exceeds total influenza deaths during flu season.

Australia shows the same pattern, but shifted six months—deaths peak in July, their winter. Singapore, 80 miles from the equator with year-round sun, shows no seasonal mortality pattern.

Multiple studies have linked mortality rates to latitude, independent of vitamin D levels, suggesting sunlight itself—particularly its infrared component—plays a direct metabolic role.

Hospitals Are Bringing Patients Outside

Armed with mounting evidence, hospitals worldwide are redesigning care spaces to maximize sunlight exposure.

A $1.5 billion hospital in Footscray, Australia, built ICU beds with direct outdoor access. King’s College Hospital in London invested £2 million to transform its rooftop into a critical care garden where up to six ICU patients can receive treatment surrounded by greenery and natural light.

St. George’s Hospital in London followed suit, creating a neurointensive care rooftop unit. Queen Camilla visited the facility in 2026 to recognize the innovation.

Randomized controlled trials using infrared vests delivering roughly 20–30 watts per square meter (comparable to sitting under a tree) showed 30% reductions in ICU length of stay and improved muscle strength in critically ill COVID-19 patients.

Metabolic Scaling Matches Solar Power Scaling

One of the paper’s most intriguing observations: metabolic rate scales with body mass to the 3/4 power across species from flies to elephants.

Solar power intercepted by an organism also scales to the 3/4 power of mass—nearly identical.

This doesn’t prove causation, but it suggests sunlight could be a universal regulator of metabolic activity across the biosphere, with mitochondria in all organisms tuned to respond to the same infrared wavelengths present in Earth’s solar photon field.

What Makes This Hypothesis Different

Earlier theories proposed infrared light works by activating a photoreceptor in cytochrome c oxidase (complex IV) or by reducing water viscosity around ATP synthase motors.

Seheult’s team doesn’t reject these mechanisms—but argues they’re incomplete.

The Marcus framework explains phenomena earlier models couldn’t: why some infrared wavelengths inhibit rather than enhance mitochondrial activity, why broadband light outperforms monochromatic sources, and why effects persist across vastly different organisms.

The paper is the first to integrate four separate literature streams:

• Mitochondrial electron transfer follows Marcus physics
• Red and near-infrared light alter mitochondrial function
• Water and protein structures affect electron transfer kinetics
• Infrared radiation changes molecular electron transfer rates

“The novelty lies in the mechanistic integration,” Seheult emphasizes, “not in any single component.”

What Comes Next

The hypothesis is testable. Future experiments could measure how different infrared wavelengths alter specific Marcus crossing configurations in isolated mitochondrial complexes, or track real-time changes in reorganization energy using advanced spectroscopy.

If validated, the implications extend far beyond biology. Urban planning, architecture, workplace design, and lighting standards may all need reconsideration.

Seheult introduces a new term: photometabolism—solar-driven, non-photosynthetic modulation of core metabolic processes.

It’s a concept that positions sunlight not as a passive environmental factor, but as an active participant in the biochemistry of life itself.

I believe that this hypothesis if true has major implications for the built environment and how we live and the type of light that we require to live, and I believe it’s one of the major reasons why we need to be treating our patients outside.

Sources

• Jeffery et al. (2025) – Longer wavelengths in sunlight penetrating human tissue
• Ma et al. (2018) – Infrared perturbation of charge separation and recombination
• Sanderson et al. (2018) – Inhibitory modulation of cytochrome c oxidase with near-infrared wavelengths
• Dai et al. (2026) – Infrared stimulation of mitochondrial metabolism in deep-sea yeast
• Hayashi et al. (2010) – Water-mediated electron transfer in iron-sulfur bridges
• Marcus and Sutin (1985) – Electron transfer reactions in chemistry

This explains a puzzling finding from earlier studies: different infrared wavelengths can either increase or decrease mitochondrial activity.

Experiments Confirm the Mechanism

A 2018 study by Ma and colleagues tested this exact principle. Researchers built a custom molecule and used mid-infrared light to excite vibrational modes.

They found infrared light slowed forward electron transfer but accelerated backward transfer—precisely what Marcus theory predicts when nuclear orientations are shifted along energy curves.

IR excitation increases the probability of donor and acceptor energies to remain in degeneracy, resulting in IR-induced electron transfer rate enhancement.

Seheult notes he and co-author Dr. Robert Fosbury spoke with Marcus himself—just months before the scientist passed away at age 102—to discuss their hypothesis.

Deep-Sea Yeast Thrives on Infrared Light—Without Photosynthesis

Perhaps the most striking evidence comes from an unexpected source: yeast living near hydrothermal vents at the bottom of the ocean.

A 2026 study by Dai and colleagues isolated yeast from sediments near a “black smoker” chimney in the central Indian Ocean, more than half a meter from superheated mineral plumes reaching 378°C.

When researchers exposed these yeast cultures to near-infrared light (810–1050 nm) in temperature-controlled conditions, growth increased dramatically compared to dark controls—even though the yeast cannot photosynthesize.

Infrared light outperformed glucose. Adding glucose increased biomass by only 1.3-fold (not statistically significant), while 880-nanometer infrared light produced a threefold increase.

When researchers blocked cytochrome c oxidase (complex IV in mitochondria), near-infrared-stimulated growth dropped by 44%—suggesting the effect operates directly on mitochondrial machinery.

Cold Temperatures, Warm Light

Even more remarkable: infrared light allowed yeast to grow at cooler temperatures where dark controls remained dormant.

At 20°C, yeast exposed to 880-nanometer light grew vigorously while dark controls showed minimal activity. The effective activation energy dropped from 12 kilocalories per mole to just 2 kilocalories per mole.

Infrared light was making up for the cold temperatures by supplying vibrational activation rather than thermal activation.

Proteomics revealed the most upregulated protein after infrared exposure was a mitochondrial ribosomal protein (MRPs8), increased 6.7-fold.

Why Broadband Sunlight May Beat Monochromatic LEDs

Clinical studies using single-wavelength infrared devices have shown benefits—from reducing ICU length of stay to improving muscle strength in COVID-19 patients.

But Seheult’s hypothesis suggests broadband infrared from the sun may be even more effective.

“Sunlight contains a broad spectrum of wavelengths that can interact with many different vibrational modes and electron transfer steps,” he explains, “rather than targeting only one narrow pathway.”

Research from Jeffery’s lab supports this. When comparing monochromatic 850-nanometer light to a 60-watt incandescent bulb (which emits broad-spectrum infrared), the incandescent bulb produced greater improvements in color blindness.

• Monochromatic 850 nm: 9% improvement (head and body), 5% (body only)
• 60W incandescent bulb: 28% improvement, sustained for weeks

The research here aligns with the hypothesis, though direct mechanistic proof in human mitochondria remains to be demonstrated.

The Modern Indoor Environment: A Metabolic Desert?

LED bulbs emit virtually no infrared radiation. Low-emissivity (Low-E) glass windows, designed to improve energy efficiency, block infrared wavelengths.

Seheult measured infrared exposure in his own dining room with windows open: 0.8 watts per square meter.

Step outside under a shade tree with grass reflecting sunlight? 41.9 watts per square meter—more than 50 times higher.

We have set up a situation where outdoors we’re getting plenty of infrared light, versus being indoors where we have Low-E glass blocking it and LED bulbs producing none.

This raises profound questions about whether chronic infrared deficiency could contribute to the rising burden of metabolic diseases, especially among populations spending most of their time indoors.

Seasonal Mortality Patterns Point to Sunlight’s Role

Death rates from heart disease, cancer, stroke, Alzheimer’s, diabetes, and respiratory illness all peak one to three weeks after the shortest day of the year and bottom out after the longest day.

This pattern holds across both infectious and non-infectious causes. The seasonal variation in heart disease deaths alone exceeds total influenza deaths during flu season.

Australia shows the same pattern, but shifted six months—deaths peak in July, their winter. Singapore, 80 miles from the equator with year-round sun, shows no seasonal mortality pattern.

Multiple studies have linked mortality rates to latitude, independent of vitamin D levels, suggesting sunlight itself—particularly its infrared component—plays a direct metabolic role.

Hospitals Are Bringing Patients Outside

Armed with mounting evidence, hospitals worldwide are redesigning care spaces to maximize sunlight exposure.

A $1.5 billion hospital in Footscray, Australia, built ICU beds with direct outdoor access. King’s College Hospital in London invested £2 million to transform its rooftop into a critical care garden where up to six ICU patients can receive treatment surrounded by greenery and natural light.

St. George’s Hospital in London followed suit, creating a neurointensive care rooftop unit. Queen Camilla visited the facility in 2026 to recognize the innovation.

Randomized controlled trials using infrared vests delivering roughly 20–30 watts per square meter (comparable to sitting under a tree) showed 30% reductions in ICU length of stay and improved muscle strength in critically ill COVID-19 patients.

Metabolic Scaling Matches Solar Power Scaling

One of the paper’s most intriguing observations: metabolic rate scales with body mass to the 3/4 power across species from flies to elephants.

Solar power intercepted by an organism also scales to the 3/4 power of mass—nearly identical.

This doesn’t prove causation, but it suggests sunlight could be a universal regulator of metabolic activity across the biosphere, with mitochondria in all organisms tuned to respond to the same infrared wavelengths present in Earth’s solar photon field.

What Makes This Hypothesis Different

Earlier theories proposed infrared light works by activating a photoreceptor in cytochrome c oxidase (complex IV) or by reducing water viscosity around ATP synthase motors.

Seheult’s team doesn’t reject these mechanisms—but argues they’re incomplete.

The Marcus framework explains phenomena earlier models couldn’t: why some infrared wavelengths inhibit rather than enhance mitochondrial activity, why broadband light outperforms monochromatic sources, and why effects persist across vastly different organisms.

The paper is the first to integrate four separate literature streams:

• Mitochondrial electron transfer follows Marcus physics
• Red and near-infrared light alter mitochondrial function
• Water and protein structures affect electron transfer kinetics
• Infrared radiation changes molecular electron transfer rates

“The novelty lies in the mechanistic integration,” Seheult emphasizes, “not in any single component.”

What Comes Next

The hypothesis is testable. Future experiments could measure how different infrared wavelengths alter specific Marcus crossing configurations in isolated mitochondrial complexes, or track real-time changes in reorganization energy using advanced spectroscopy.

If validated, the implications extend far beyond biology. Urban planning, architecture, workplace design, and lighting standards may all need reconsideration.

Seheult introduces a new term: photometabolism—solar-driven, non-photosynthetic modulation of core metabolic processes.

It’s a concept that positions sunlight not as a passive environmental factor, but as an active participant in the biochemistry of life itself.

I believe that this hypothesis if true has major implications for the built environment and how we live and the type of light that we require to live, and I believe it’s one of the major reasons why we need to be treating our patients outside.

Sources

• Jeffery et al. (2025) – Longer wavelengths in sunlight penetrating human tissue
• Ma et al. (2018) – Infrared perturbation of charge separation and recombination
• Sanderson et al. (2018) – Inhibitory modulation of cytochrome c oxidase with near-infrared wavelengths
• Dai et al. (2026) – Infrared stimulation of mitochondrial metabolism in deep-sea yeast
• Hayashi et al. (2010) – Water-mediated electron transfer in iron-sulfur bridges
• Marcus and Sutin (1985) – Electron transfer reactions in chemistry

This explains a puzzling finding from earlier studies: different infrared wavelengths can either increase or decrease mitochondrial activity.

Experiments Confirm the Mechanism

A 2018 study by Ma and colleagues tested this exact principle. Researchers built a custom molecule and used mid-infrared light to excite vibrational modes.

They found infrared light slowed forward electron transfer but accelerated backward transfer—precisely what Marcus theory predicts when nuclear orientations are shifted along energy curves.

IR excitation increases the probability of donor and acceptor energies to remain in degeneracy, resulting in IR-induced electron transfer rate enhancement.

Seheult notes he and co-author Dr. Robert Fosbury spoke with Marcus himself—just months before the scientist passed away at age 102—to discuss their hypothesis.

Deep-Sea Yeast Thrives on Infrared Light—Without Photosynthesis

Perhaps the most striking evidence comes from an unexpected source: yeast living near hydrothermal vents at the bottom of the ocean.

A 2026 study by Dai and colleagues isolated yeast from sediments near a “black smoker” chimney in the central Indian Ocean, more than half a meter from superheated mineral plumes reaching 378°C.

When researchers exposed these yeast cultures to near-infrared light (810–1050 nm) in temperature-controlled conditions, growth increased dramatically compared to dark controls—even though the yeast cannot photosynthesize.

Infrared light outperformed glucose. Adding glucose increased biomass by only 1.3-fold (not statistically significant), while 880-nanometer infrared light produced a threefold increase.

When researchers blocked cytochrome c oxidase (complex IV in mitochondria), near-infrared-stimulated growth dropped by 44%—suggesting the effect operates directly on mitochondrial machinery.

Cold Temperatures, Warm Light

Even more remarkable: infrared light allowed yeast to grow at cooler temperatures where dark controls remained dormant.

At 20°C, yeast exposed to 880-nanometer light grew vigorously while dark controls showed minimal activity. The effective activation energy dropped from 12 kilocalories per mole to just 2 kilocalories per mole.

Infrared light was making up for the cold temperatures by supplying vibrational activation rather than thermal activation.

Proteomics revealed the most upregulated protein after infrared exposure was a mitochondrial ribosomal protein (MRPs8), increased 6.7-fold.

Why Broadband Sunlight May Beat Monochromatic LEDs

Clinical studies using single-wavelength infrared devices have shown benefits—from reducing ICU length of stay to improving muscle strength in COVID-19 patients.

But Seheult’s hypothesis suggests broadband infrared from the sun may be even more effective.

“Sunlight contains a broad spectrum of wavelengths that can interact with many different vibrational modes and electron transfer steps,” he explains, “rather than targeting only one narrow pathway.”

Research from Jeffery’s lab supports this. When comparing monochromatic 850-nanometer light to a 60-watt incandescent bulb (which emits broad-spectrum infrared), the incandescent bulb produced greater improvements in color blindness.

• Monochromatic 850 nm: 9% improvement (head and body), 5% (body only)
• 60W incandescent bulb: 28% improvement, sustained for weeks

The research here aligns with the hypothesis, though direct mechanistic proof in human mitochondria remains to be demonstrated.

The Modern Indoor Environment: A Metabolic Desert?

LED bulbs emit virtually no infrared radiation. Low-emissivity (Low-E) glass windows, designed to improve energy efficiency, block infrared wavelengths.

Seheult measured infrared exposure in his own dining room with windows open: 0.8 watts per square meter.

Step outside under a shade tree with grass reflecting sunlight? 41.9 watts per square meter—more than 50 times higher.

We have set up a situation where outdoors we’re getting plenty of infrared light, versus being indoors where we have Low-E glass blocking it and LED bulbs producing none.

This raises profound questions about whether chronic infrared deficiency could contribute to the rising burden of metabolic diseases, especially among populations spending most of their time indoors.

Seasonal Mortality Patterns Point to Sunlight’s Role

Death rates from heart disease, cancer, stroke, Alzheimer’s, diabetes, and respiratory illness all peak one to three weeks after the shortest day of the year and bottom out after the longest day.

This pattern holds across both infectious and non-infectious causes. The seasonal variation in heart disease deaths alone exceeds total influenza deaths during flu season.

Australia shows the same pattern, but shifted six months—deaths peak in July, their winter. Singapore, 80 miles from the equator with year-round sun, shows no seasonal mortality pattern.

Multiple studies have linked mortality rates to latitude, independent of vitamin D levels, suggesting sunlight itself—particularly its infrared component—plays a direct metabolic role.

Hospitals Are Bringing Patients Outside

Armed with mounting evidence, hospitals worldwide are redesigning care spaces to maximize sunlight exposure.

A $1.5 billion hospital in Footscray, Australia, built ICU beds with direct outdoor access. King’s College Hospital in London invested £2 million to transform its rooftop into a critical care garden where up to six ICU patients can receive treatment surrounded by greenery and natural light.

St. George’s Hospital in London followed suit, creating a neurointensive care rooftop unit. Queen Camilla visited the facility in 2026 to recognize the innovation.

Randomized controlled trials using infrared vests delivering roughly 20–30 watts per square meter (comparable to sitting under a tree) showed 30% reductions in ICU length of stay and improved muscle strength in critically ill COVID-19 patients.

Metabolic Scaling Matches Solar Power Scaling

One of the paper’s most intriguing observations: metabolic rate scales with body mass to the 3/4 power across species from flies to elephants.

Solar power intercepted by an organism also scales to the 3/4 power of mass—nearly identical.

This doesn’t prove causation, but it suggests sunlight could be a universal regulator of metabolic activity across the biosphere, with mitochondria in all organisms tuned to respond to the same infrared wavelengths present in Earth’s solar photon field.

What Makes This Hypothesis Different

Earlier theories proposed infrared light works by activating a photoreceptor in cytochrome c oxidase (complex IV) or by reducing water viscosity around ATP synthase motors.

Seheult’s team doesn’t reject these mechanisms—but argues they’re incomplete.

The Marcus framework explains phenomena earlier models couldn’t: why some infrared wavelengths inhibit rather than enhance mitochondrial activity, why broadband light outperforms monochromatic sources, and why effects persist across vastly different organisms.

The paper is the first to integrate four separate literature streams:

• Mitochondrial electron transfer follows Marcus physics
• Red and near-infrared light alter mitochondrial function
• Water and protein structures affect electron transfer kinetics
• Infrared radiation changes molecular electron transfer rates

“The novelty lies in the mechanistic integration,” Seheult emphasizes, “not in any single component.”

What Comes Next

The hypothesis is testable. Future experiments could measure how different infrared wavelengths alter specific Marcus crossing configurations in isolated mitochondrial complexes, or track real-time changes in reorganization energy using advanced spectroscopy.

If validated, the implications extend far beyond biology. Urban planning, architecture, workplace design, and lighting standards may all need reconsideration.

Seheult introduces a new term: photometabolism—solar-driven, non-photosynthetic modulation of core metabolic processes.

It’s a concept that positions sunlight not as a passive environmental factor, but as an active participant in the biochemistry of life itself.

I believe that this hypothesis if true has major implications for the built environment and how we live and the type of light that we require to live, and I believe it’s one of the major reasons why we need to be treating our patients outside.

Sources

• Jeffery et al. (2025) – Longer wavelengths in sunlight penetrating human tissue
• Ma et al. (2018) – Infrared perturbation of charge separation and recombination
• Sanderson et al. (2018) – Inhibitory modulation of cytochrome c oxidase with near-infrared wavelengths
• Dai et al. (2026) – Infrared stimulation of mitochondrial metabolism in deep-sea yeast
• Hayashi et al. (2010) – Water-mediated electron transfer in iron-sulfur bridges
• Marcus and Sutin (1985) – Electron transfer reactions in chemistry

• If the crossing point is already accessible: Infrared light can push molecules away from optimal configurations, slowing electron transfer
• If the crossing point requires activation: Infrared light can push molecules toward optimal configurations, speeding electron transfer

This explains a puzzling finding from earlier studies: different infrared wavelengths can either increase or decrease mitochondrial activity.

Experiments Confirm the Mechanism

A 2018 study by Ma and colleagues tested this exact principle. Researchers built a custom molecule and used mid-infrared light to excite vibrational modes.

They found infrared light slowed forward electron transfer but accelerated backward transfer—precisely what Marcus theory predicts when nuclear orientations are shifted along energy curves.

IR excitation increases the probability of donor and acceptor energies to remain in degeneracy, resulting in IR-induced electron transfer rate enhancement.

Seheult notes he and co-author Dr. Robert Fosbury spoke with Marcus himself—just months before the scientist passed away at age 102—to discuss their hypothesis.

Deep-Sea Yeast Thrives on Infrared Light—Without Photosynthesis

Perhaps the most striking evidence comes from an unexpected source: yeast living near hydrothermal vents at the bottom of the ocean.

A 2026 study by Dai and colleagues isolated yeast from sediments near a “black smoker” chimney in the central Indian Ocean, more than half a meter from superheated mineral plumes reaching 378°C.

When researchers exposed these yeast cultures to near-infrared light (810–1050 nm) in temperature-controlled conditions, growth increased dramatically compared to dark controls—even though the yeast cannot photosynthesize.

Infrared light outperformed glucose. Adding glucose increased biomass by only 1.3-fold (not statistically significant), while 880-nanometer infrared light produced a threefold increase.

When researchers blocked cytochrome c oxidase (complex IV in mitochondria), near-infrared-stimulated growth dropped by 44%—suggesting the effect operates directly on mitochondrial machinery.

Cold Temperatures, Warm Light

Even more remarkable: infrared light allowed yeast to grow at cooler temperatures where dark controls remained dormant.

At 20°C, yeast exposed to 880-nanometer light grew vigorously while dark controls showed minimal activity. The effective activation energy dropped from 12 kilocalories per mole to just 2 kilocalories per mole.

Infrared light was making up for the cold temperatures by supplying vibrational activation rather than thermal activation.

Proteomics revealed the most upregulated protein after infrared exposure was a mitochondrial ribosomal protein (MRPs8), increased 6.7-fold.

Why Broadband Sunlight May Beat Monochromatic LEDs

Clinical studies using single-wavelength infrared devices have shown benefits—from reducing ICU length of stay to improving muscle strength in COVID-19 patients.

But Seheult’s hypothesis suggests broadband infrared from the sun may be even more effective.

“Sunlight contains a broad spectrum of wavelengths that can interact with many different vibrational modes and electron transfer steps,” he explains, “rather than targeting only one narrow pathway.”

Research from Jeffery’s lab supports this. When comparing monochromatic 850-nanometer light to a 60-watt incandescent bulb (which emits broad-spectrum infrared), the incandescent bulb produced greater improvements in color blindness.

• Monochromatic 850 nm: 9% improvement (head and body), 5% (body only)
• 60W incandescent bulb: 28% improvement, sustained for weeks

The research here aligns with the hypothesis, though direct mechanistic proof in human mitochondria remains to be demonstrated.

The Modern Indoor Environment: A Metabolic Desert?

LED bulbs emit virtually no infrared radiation. Low-emissivity (Low-E) glass windows, designed to improve energy efficiency, block infrared wavelengths.

Seheult measured infrared exposure in his own dining room with windows open: 0.8 watts per square meter.

Step outside under a shade tree with grass reflecting sunlight? 41.9 watts per square meter—more than 50 times higher.

We have set up a situation where outdoors we’re getting plenty of infrared light, versus being indoors where we have Low-E glass blocking it and LED bulbs producing none.

This raises profound questions about whether chronic infrared deficiency could contribute to the rising burden of metabolic diseases, especially among populations spending most of their time indoors.

Seasonal Mortality Patterns Point to Sunlight’s Role

Death rates from heart disease, cancer, stroke, Alzheimer’s, diabetes, and respiratory illness all peak one to three weeks after the shortest day of the year and bottom out after the longest day.

This pattern holds across both infectious and non-infectious causes. The seasonal variation in heart disease deaths alone exceeds total influenza deaths during flu season.

Australia shows the same pattern, but shifted six months—deaths peak in July, their winter. Singapore, 80 miles from the equator with year-round sun, shows no seasonal mortality pattern.

Multiple studies have linked mortality rates to latitude, independent of vitamin D levels, suggesting sunlight itself—particularly its infrared component—plays a direct metabolic role.

Hospitals Are Bringing Patients Outside

Armed with mounting evidence, hospitals worldwide are redesigning care spaces to maximize sunlight exposure.

A $1.5 billion hospital in Footscray, Australia, built ICU beds with direct outdoor access. King’s College Hospital in London invested £2 million to transform its rooftop into a critical care garden where up to six ICU patients can receive treatment surrounded by greenery and natural light.

St. George’s Hospital in London followed suit, creating a neurointensive care rooftop unit. Queen Camilla visited the facility in 2026 to recognize the innovation.

Randomized controlled trials using infrared vests delivering roughly 20–30 watts per square meter (comparable to sitting under a tree) showed 30% reductions in ICU length of stay and improved muscle strength in critically ill COVID-19 patients.

Metabolic Scaling Matches Solar Power Scaling

One of the paper’s most intriguing observations: metabolic rate scales with body mass to the 3/4 power across species from flies to elephants.

Solar power intercepted by an organism also scales to the 3/4 power of mass—nearly identical.

This doesn’t prove causation, but it suggests sunlight could be a universal regulator of metabolic activity across the biosphere, with mitochondria in all organisms tuned to respond to the same infrared wavelengths present in Earth’s solar photon field.

What Makes This Hypothesis Different

Earlier theories proposed infrared light works by activating a photoreceptor in cytochrome c oxidase (complex IV) or by reducing water viscosity around ATP synthase motors.

Seheult’s team doesn’t reject these mechanisms—but argues they’re incomplete.

The Marcus framework explains phenomena earlier models couldn’t: why some infrared wavelengths inhibit rather than enhance mitochondrial activity, why broadband light outperforms monochromatic sources, and why effects persist across vastly different organisms.

The paper is the first to integrate four separate literature streams:

• Mitochondrial electron transfer follows Marcus physics
• Red and near-infrared light alter mitochondrial function
• Water and protein structures affect electron transfer kinetics
• Infrared radiation changes molecular electron transfer rates

“The novelty lies in the mechanistic integration,” Seheult emphasizes, “not in any single component.”

What Comes Next

The hypothesis is testable. Future experiments could measure how different infrared wavelengths alter specific Marcus crossing configurations in isolated mitochondrial complexes, or track real-time changes in reorganization energy using advanced spectroscopy.

If validated, the implications extend far beyond biology. Urban planning, architecture, workplace design, and lighting standards may all need reconsideration.

Seheult introduces a new term: photometabolism—solar-driven, non-photosynthetic modulation of core metabolic processes.

It’s a concept that positions sunlight not as a passive environmental factor, but as an active participant in the biochemistry of life itself.

I believe that this hypothesis if true has major implications for the built environment and how we live and the type of light that we require to live, and I believe it’s one of the major reasons why we need to be treating our patients outside.

Sources

• Jeffery et al. (2025) – Longer wavelengths in sunlight penetrating human tissue
• Ma et al. (2018) – Infrared perturbation of charge separation and recombination
• Sanderson et al. (2018) – Inhibitory modulation of cytochrome c oxidase with near-infrared wavelengths
• Dai et al. (2026) – Infrared stimulation of mitochondrial metabolism in deep-sea yeast
• Hayashi et al. (2010) – Water-mediated electron transfer in iron-sulfur bridges
• Marcus and Sutin (1985) – Electron transfer reactions in chemistry

• If the crossing point is already accessible: Infrared light can push molecules away from optimal configurations, slowing electron transfer
• If the crossing point requires activation: Infrared light can push molecules toward optimal configurations, speeding electron transfer

This explains a puzzling finding from earlier studies: different infrared wavelengths can either increase or decrease mitochondrial activity.

Experiments Confirm the Mechanism

A 2018 study by Ma and colleagues tested this exact principle. Researchers built a custom molecule and used mid-infrared light to excite vibrational modes.

They found infrared light slowed forward electron transfer but accelerated backward transfer—precisely what Marcus theory predicts when nuclear orientations are shifted along energy curves.

IR excitation increases the probability of donor and acceptor energies to remain in degeneracy, resulting in IR-induced electron transfer rate enhancement.

Seheult notes he and co-author Dr. Robert Fosbury spoke with Marcus himself—just months before the scientist passed away at age 102—to discuss their hypothesis.

Deep-Sea Yeast Thrives on Infrared Light—Without Photosynthesis

Perhaps the most striking evidence comes from an unexpected source: yeast living near hydrothermal vents at the bottom of the ocean.

A 2026 study by Dai and colleagues isolated yeast from sediments near a “black smoker” chimney in the central Indian Ocean, more than half a meter from superheated mineral plumes reaching 378°C.

When researchers exposed these yeast cultures to near-infrared light (810–1050 nm) in temperature-controlled conditions, growth increased dramatically compared to dark controls—even though the yeast cannot photosynthesize.

Infrared light outperformed glucose. Adding glucose increased biomass by only 1.3-fold (not statistically significant), while 880-nanometer infrared light produced a threefold increase.

When researchers blocked cytochrome c oxidase (complex IV in mitochondria), near-infrared-stimulated growth dropped by 44%—suggesting the effect operates directly on mitochondrial machinery.

Cold Temperatures, Warm Light

Even more remarkable: infrared light allowed yeast to grow at cooler temperatures where dark controls remained dormant.

At 20°C, yeast exposed to 880-nanometer light grew vigorously while dark controls showed minimal activity. The effective activation energy dropped from 12 kilocalories per mole to just 2 kilocalories per mole.

Infrared light was making up for the cold temperatures by supplying vibrational activation rather than thermal activation.

Proteomics revealed the most upregulated protein after infrared exposure was a mitochondrial ribosomal protein (MRPs8), increased 6.7-fold.

Why Broadband Sunlight May Beat Monochromatic LEDs

Clinical studies using single-wavelength infrared devices have shown benefits—from reducing ICU length of stay to improving muscle strength in COVID-19 patients.

But Seheult’s hypothesis suggests broadband infrared from the sun may be even more effective.

“Sunlight contains a broad spectrum of wavelengths that can interact with many different vibrational modes and electron transfer steps,” he explains, “rather than targeting only one narrow pathway.”

Research from Jeffery’s lab supports this. When comparing monochromatic 850-nanometer light to a 60-watt incandescent bulb (which emits broad-spectrum infrared), the incandescent bulb produced greater improvements in color blindness.

• Monochromatic 850 nm: 9% improvement (head and body), 5% (body only)
• 60W incandescent bulb: 28% improvement, sustained for weeks

The research here aligns with the hypothesis, though direct mechanistic proof in human mitochondria remains to be demonstrated.

The Modern Indoor Environment: A Metabolic Desert?

LED bulbs emit virtually no infrared radiation. Low-emissivity (Low-E) glass windows, designed to improve energy efficiency, block infrared wavelengths.

Seheult measured infrared exposure in his own dining room with windows open: 0.8 watts per square meter.

Step outside under a shade tree with grass reflecting sunlight? 41.9 watts per square meter—more than 50 times higher.

We have set up a situation where outdoors we’re getting plenty of infrared light, versus being indoors where we have Low-E glass blocking it and LED bulbs producing none.

This raises profound questions about whether chronic infrared deficiency could contribute to the rising burden of metabolic diseases, especially among populations spending most of their time indoors.

Seasonal Mortality Patterns Point to Sunlight’s Role

Death rates from heart disease, cancer, stroke, Alzheimer’s, diabetes, and respiratory illness all peak one to three weeks after the shortest day of the year and bottom out after the longest day.

This pattern holds across both infectious and non-infectious causes. The seasonal variation in heart disease deaths alone exceeds total influenza deaths during flu season.

Australia shows the same pattern, but shifted six months—deaths peak in July, their winter. Singapore, 80 miles from the equator with year-round sun, shows no seasonal mortality pattern.

Multiple studies have linked mortality rates to latitude, independent of vitamin D levels, suggesting sunlight itself—particularly its infrared component—plays a direct metabolic role.

Hospitals Are Bringing Patients Outside

Armed with mounting evidence, hospitals worldwide are redesigning care spaces to maximize sunlight exposure.

A $1.5 billion hospital in Footscray, Australia, built ICU beds with direct outdoor access. King’s College Hospital in London invested £2 million to transform its rooftop into a critical care garden where up to six ICU patients can receive treatment surrounded by greenery and natural light.

St. George’s Hospital in London followed suit, creating a neurointensive care rooftop unit. Queen Camilla visited the facility in 2026 to recognize the innovation.

Randomized controlled trials using infrared vests delivering roughly 20–30 watts per square meter (comparable to sitting under a tree) showed 30% reductions in ICU length of stay and improved muscle strength in critically ill COVID-19 patients.

Metabolic Scaling Matches Solar Power Scaling

One of the paper’s most intriguing observations: metabolic rate scales with body mass to the 3/4 power across species from flies to elephants.

Solar power intercepted by an organism also scales to the 3/4 power of mass—nearly identical.

This doesn’t prove causation, but it suggests sunlight could be a universal regulator of metabolic activity across the biosphere, with mitochondria in all organisms tuned to respond to the same infrared wavelengths present in Earth’s solar photon field.

What Makes This Hypothesis Different

Earlier theories proposed infrared light works by activating a photoreceptor in cytochrome c oxidase (complex IV) or by reducing water viscosity around ATP synthase motors.

Seheult’s team doesn’t reject these mechanisms—but argues they’re incomplete.

The Marcus framework explains phenomena earlier models couldn’t: why some infrared wavelengths inhibit rather than enhance mitochondrial activity, why broadband light outperforms monochromatic sources, and why effects persist across vastly different organisms.

The paper is the first to integrate four separate literature streams:

• Mitochondrial electron transfer follows Marcus physics
• Red and near-infrared light alter mitochondrial function
• Water and protein structures affect electron transfer kinetics
• Infrared radiation changes molecular electron transfer rates

“The novelty lies in the mechanistic integration,” Seheult emphasizes, “not in any single component.”

What Comes Next

The hypothesis is testable. Future experiments could measure how different infrared wavelengths alter specific Marcus crossing configurations in isolated mitochondrial complexes, or track real-time changes in reorganization energy using advanced spectroscopy.

If validated, the implications extend far beyond biology. Urban planning, architecture, workplace design, and lighting standards may all need reconsideration.

Seheult introduces a new term: photometabolism—solar-driven, non-photosynthetic modulation of core metabolic processes.

It’s a concept that positions sunlight not as a passive environmental factor, but as an active participant in the biochemistry of life itself.

I believe that this hypothesis if true has major implications for the built environment and how we live and the type of light that we require to live, and I believe it’s one of the major reasons why we need to be treating our patients outside.

Sources

• Jeffery et al. (2025) – Longer wavelengths in sunlight penetrating human tissue
• Ma et al. (2018) – Infrared perturbation of charge separation and recombination
• Sanderson et al. (2018) – Inhibitory modulation of cytochrome c oxidase with near-infrared wavelengths
• Dai et al. (2026) – Infrared stimulation of mitochondrial metabolism in deep-sea yeast
• Hayashi et al. (2010) – Water-mediated electron transfer in iron-sulfur bridges
• Marcus and Sutin (1985) – Electron transfer reactions in chemistry

When infrared light hits these structures, it causes them to vibrate. This shifts the probability that molecules will be in the right arrangement for electron transfer to occur.

• If the crossing point is already accessible: Infrared light can push molecules away from optimal configurations, slowing electron transfer
• If the crossing point requires activation: Infrared light can push molecules toward optimal configurations, speeding electron transfer

This explains a puzzling finding from earlier studies: different infrared wavelengths can either increase or decrease mitochondrial activity.

Experiments Confirm the Mechanism

A 2018 study by Ma and colleagues tested this exact principle. Researchers built a custom molecule and used mid-infrared light to excite vibrational modes.

They found infrared light slowed forward electron transfer but accelerated backward transfer—precisely what Marcus theory predicts when nuclear orientations are shifted along energy curves.

IR excitation increases the probability of donor and acceptor energies to remain in degeneracy, resulting in IR-induced electron transfer rate enhancement.

Seheult notes he and co-author Dr. Robert Fosbury spoke with Marcus himself—just months before the scientist passed away at age 102—to discuss their hypothesis.

Deep-Sea Yeast Thrives on Infrared Light—Without Photosynthesis

Perhaps the most striking evidence comes from an unexpected source: yeast living near hydrothermal vents at the bottom of the ocean.

A 2026 study by Dai and colleagues isolated yeast from sediments near a “black smoker” chimney in the central Indian Ocean, more than half a meter from superheated mineral plumes reaching 378°C.

When researchers exposed these yeast cultures to near-infrared light (810–1050 nm) in temperature-controlled conditions, growth increased dramatically compared to dark controls—even though the yeast cannot photosynthesize.

Infrared light outperformed glucose. Adding glucose increased biomass by only 1.3-fold (not statistically significant), while 880-nanometer infrared light produced a threefold increase.

When researchers blocked cytochrome c oxidase (complex IV in mitochondria), near-infrared-stimulated growth dropped by 44%—suggesting the effect operates directly on mitochondrial machinery.

Cold Temperatures, Warm Light

Even more remarkable: infrared light allowed yeast to grow at cooler temperatures where dark controls remained dormant.

At 20°C, yeast exposed to 880-nanometer light grew vigorously while dark controls showed minimal activity. The effective activation energy dropped from 12 kilocalories per mole to just 2 kilocalories per mole.

Infrared light was making up for the cold temperatures by supplying vibrational activation rather than thermal activation.

Proteomics revealed the most upregulated protein after infrared exposure was a mitochondrial ribosomal protein (MRPs8), increased 6.7-fold.

Why Broadband Sunlight May Beat Monochromatic LEDs

Clinical studies using single-wavelength infrared devices have shown benefits—from reducing ICU length of stay to improving muscle strength in COVID-19 patients.

But Seheult’s hypothesis suggests broadband infrared from the sun may be even more effective.

“Sunlight contains a broad spectrum of wavelengths that can interact with many different vibrational modes and electron transfer steps,” he explains, “rather than targeting only one narrow pathway.”

Research from Jeffery’s lab supports this. When comparing monochromatic 850-nanometer light to a 60-watt incandescent bulb (which emits broad-spectrum infrared), the incandescent bulb produced greater improvements in color blindness.

• Monochromatic 850 nm: 9% improvement (head and body), 5% (body only)
• 60W incandescent bulb: 28% improvement, sustained for weeks

The research here aligns with the hypothesis, though direct mechanistic proof in human mitochondria remains to be demonstrated.

The Modern Indoor Environment: A Metabolic Desert?

LED bulbs emit virtually no infrared radiation. Low-emissivity (Low-E) glass windows, designed to improve energy efficiency, block infrared wavelengths.

Seheult measured infrared exposure in his own dining room with windows open: 0.8 watts per square meter.

Step outside under a shade tree with grass reflecting sunlight? 41.9 watts per square meter—more than 50 times higher.

We have set up a situation where outdoors we’re getting plenty of infrared light, versus being indoors where we have Low-E glass blocking it and LED bulbs producing none.

This raises profound questions about whether chronic infrared deficiency could contribute to the rising burden of metabolic diseases, especially among populations spending most of their time indoors.

Seasonal Mortality Patterns Point to Sunlight’s Role

Death rates from heart disease, cancer, stroke, Alzheimer’s, diabetes, and respiratory illness all peak one to three weeks after the shortest day of the year and bottom out after the longest day.

This pattern holds across both infectious and non-infectious causes. The seasonal variation in heart disease deaths alone exceeds total influenza deaths during flu season.

Australia shows the same pattern, but shifted six months—deaths peak in July, their winter. Singapore, 80 miles from the equator with year-round sun, shows no seasonal mortality pattern.

Multiple studies have linked mortality rates to latitude, independent of vitamin D levels, suggesting sunlight itself—particularly its infrared component—plays a direct metabolic role.

Hospitals Are Bringing Patients Outside

Armed with mounting evidence, hospitals worldwide are redesigning care spaces to maximize sunlight exposure.

A $1.5 billion hospital in Footscray, Australia, built ICU beds with direct outdoor access. King’s College Hospital in London invested £2 million to transform its rooftop into a critical care garden where up to six ICU patients can receive treatment surrounded by greenery and natural light.

St. George’s Hospital in London followed suit, creating a neurointensive care rooftop unit. Queen Camilla visited the facility in 2026 to recognize the innovation.

Randomized controlled trials using infrared vests delivering roughly 20–30 watts per square meter (comparable to sitting under a tree) showed 30% reductions in ICU length of stay and improved muscle strength in critically ill COVID-19 patients.

Metabolic Scaling Matches Solar Power Scaling

One of the paper’s most intriguing observations: metabolic rate scales with body mass to the 3/4 power across species from flies to elephants.

Solar power intercepted by an organism also scales to the 3/4 power of mass—nearly identical.

This doesn’t prove causation, but it suggests sunlight could be a universal regulator of metabolic activity across the biosphere, with mitochondria in all organisms tuned to respond to the same infrared wavelengths present in Earth’s solar photon field.

What Makes This Hypothesis Different

Earlier theories proposed infrared light works by activating a photoreceptor in cytochrome c oxidase (complex IV) or by reducing water viscosity around ATP synthase motors.

Seheult’s team doesn’t reject these mechanisms—but argues they’re incomplete.

The Marcus framework explains phenomena earlier models couldn’t: why some infrared wavelengths inhibit rather than enhance mitochondrial activity, why broadband light outperforms monochromatic sources, and why effects persist across vastly different organisms.

The paper is the first to integrate four separate literature streams:

• Mitochondrial electron transfer follows Marcus physics
• Red and near-infrared light alter mitochondrial function
• Water and protein structures affect electron transfer kinetics
• Infrared radiation changes molecular electron transfer rates

“The novelty lies in the mechanistic integration,” Seheult emphasizes, “not in any single component.”

What Comes Next

The hypothesis is testable. Future experiments could measure how different infrared wavelengths alter specific Marcus crossing configurations in isolated mitochondrial complexes, or track real-time changes in reorganization energy using advanced spectroscopy.

If validated, the implications extend far beyond biology. Urban planning, architecture, workplace design, and lighting standards may all need reconsideration.

Seheult introduces a new term: photometabolism—solar-driven, non-photosynthetic modulation of core metabolic processes.

It’s a concept that positions sunlight not as a passive environmental factor, but as an active participant in the biochemistry of life itself.

I believe that this hypothesis if true has major implications for the built environment and how we live and the type of light that we require to live, and I believe it’s one of the major reasons why we need to be treating our patients outside.

Sources

• Jeffery et al. (2025) – Longer wavelengths in sunlight penetrating human tissue
• Ma et al. (2018) – Infrared perturbation of charge separation and recombination
• Sanderson et al. (2018) – Inhibitory modulation of cytochrome c oxidase with near-infrared wavelengths
• Dai et al. (2026) – Infrared stimulation of mitochondrial metabolism in deep-sea yeast
• Hayashi et al. (2010) – Water-mediated electron transfer in iron-sulfur bridges
• Marcus and Sutin (1985) – Electron transfer reactions in chemistry

When infrared light hits these structures, it causes them to vibrate. This shifts the probability that molecules will be in the right arrangement for electron transfer to occur.

• If the crossing point is already accessible: Infrared light can push molecules away from optimal configurations, slowing electron transfer
• If the crossing point requires activation: Infrared light can push molecules toward optimal configurations, speeding electron transfer

This explains a puzzling finding from earlier studies: different infrared wavelengths can either increase or decrease mitochondrial activity.

Experiments Confirm the Mechanism

A 2018 study by Ma and colleagues tested this exact principle. Researchers built a custom molecule and used mid-infrared light to excite vibrational modes.

They found infrared light slowed forward electron transfer but accelerated backward transfer—precisely what Marcus theory predicts when nuclear orientations are shifted along energy curves.

IR excitation increases the probability of donor and acceptor energies to remain in degeneracy, resulting in IR-induced electron transfer rate enhancement.

Seheult notes he and co-author Dr. Robert Fosbury spoke with Marcus himself—just months before the scientist passed away at age 102—to discuss their hypothesis.

Deep-Sea Yeast Thrives on Infrared Light—Without Photosynthesis

Perhaps the most striking evidence comes from an unexpected source: yeast living near hydrothermal vents at the bottom of the ocean.

A 2026 study by Dai and colleagues isolated yeast from sediments near a “black smoker” chimney in the central Indian Ocean, more than half a meter from superheated mineral plumes reaching 378°C.

When researchers exposed these yeast cultures to near-infrared light (810–1050 nm) in temperature-controlled conditions, growth increased dramatically compared to dark controls—even though the yeast cannot photosynthesize.

Infrared light outperformed glucose. Adding glucose increased biomass by only 1.3-fold (not statistically significant), while 880-nanometer infrared light produced a threefold increase.

When researchers blocked cytochrome c oxidase (complex IV in mitochondria), near-infrared-stimulated growth dropped by 44%—suggesting the effect operates directly on mitochondrial machinery.

Cold Temperatures, Warm Light

Even more remarkable: infrared light allowed yeast to grow at cooler temperatures where dark controls remained dormant.

At 20°C, yeast exposed to 880-nanometer light grew vigorously while dark controls showed minimal activity. The effective activation energy dropped from 12 kilocalories per mole to just 2 kilocalories per mole.

Infrared light was making up for the cold temperatures by supplying vibrational activation rather than thermal activation.

Proteomics revealed the most upregulated protein after infrared exposure was a mitochondrial ribosomal protein (MRPs8), increased 6.7-fold.

Why Broadband Sunlight May Beat Monochromatic LEDs

Clinical studies using single-wavelength infrared devices have shown benefits—from reducing ICU length of stay to improving muscle strength in COVID-19 patients.

But Seheult’s hypothesis suggests broadband infrared from the sun may be even more effective.

“Sunlight contains a broad spectrum of wavelengths that can interact with many different vibrational modes and electron transfer steps,” he explains, “rather than targeting only one narrow pathway.”

Research from Jeffery’s lab supports this. When comparing monochromatic 850-nanometer light to a 60-watt incandescent bulb (which emits broad-spectrum infrared), the incandescent bulb produced greater improvements in color blindness.

• Monochromatic 850 nm: 9% improvement (head and body), 5% (body only)
• 60W incandescent bulb: 28% improvement, sustained for weeks

The research here aligns with the hypothesis, though direct mechanistic proof in human mitochondria remains to be demonstrated.

The Modern Indoor Environment: A Metabolic Desert?

LED bulbs emit virtually no infrared radiation. Low-emissivity (Low-E) glass windows, designed to improve energy efficiency, block infrared wavelengths.

Seheult measured infrared exposure in his own dining room with windows open: 0.8 watts per square meter.

Step outside under a shade tree with grass reflecting sunlight? 41.9 watts per square meter—more than 50 times higher.

We have set up a situation where outdoors we’re getting plenty of infrared light, versus being indoors where we have Low-E glass blocking it and LED bulbs producing none.

This raises profound questions about whether chronic infrared deficiency could contribute to the rising burden of metabolic diseases, especially among populations spending most of their time indoors.

Seasonal Mortality Patterns Point to Sunlight’s Role

Death rates from heart disease, cancer, stroke, Alzheimer’s, diabetes, and respiratory illness all peak one to three weeks after the shortest day of the year and bottom out after the longest day.

This pattern holds across both infectious and non-infectious causes. The seasonal variation in heart disease deaths alone exceeds total influenza deaths during flu season.

Australia shows the same pattern, but shifted six months—deaths peak in July, their winter. Singapore, 80 miles from the equator with year-round sun, shows no seasonal mortality pattern.

Multiple studies have linked mortality rates to latitude, independent of vitamin D levels, suggesting sunlight itself—particularly its infrared component—plays a direct metabolic role.

Hospitals Are Bringing Patients Outside

Armed with mounting evidence, hospitals worldwide are redesigning care spaces to maximize sunlight exposure.

A $1.5 billion hospital in Footscray, Australia, built ICU beds with direct outdoor access. King’s College Hospital in London invested £2 million to transform its rooftop into a critical care garden where up to six ICU patients can receive treatment surrounded by greenery and natural light.

St. George’s Hospital in London followed suit, creating a neurointensive care rooftop unit. Queen Camilla visited the facility in 2026 to recognize the innovation.

Randomized controlled trials using infrared vests delivering roughly 20–30 watts per square meter (comparable to sitting under a tree) showed 30% reductions in ICU length of stay and improved muscle strength in critically ill COVID-19 patients.

Metabolic Scaling Matches Solar Power Scaling

One of the paper’s most intriguing observations: metabolic rate scales with body mass to the 3/4 power across species from flies to elephants.

Solar power intercepted by an organism also scales to the 3/4 power of mass—nearly identical.

This doesn’t prove causation, but it suggests sunlight could be a universal regulator of metabolic activity across the biosphere, with mitochondria in all organisms tuned to respond to the same infrared wavelengths present in Earth’s solar photon field.

What Makes This Hypothesis Different

Earlier theories proposed infrared light works by activating a photoreceptor in cytochrome c oxidase (complex IV) or by reducing water viscosity around ATP synthase motors.

Seheult’s team doesn’t reject these mechanisms—but argues they’re incomplete.

The Marcus framework explains phenomena earlier models couldn’t: why some infrared wavelengths inhibit rather than enhance mitochondrial activity, why broadband light outperforms monochromatic sources, and why effects persist across vastly different organisms.

The paper is the first to integrate four separate literature streams:

• Mitochondrial electron transfer follows Marcus physics
• Red and near-infrared light alter mitochondrial function
• Water and protein structures affect electron transfer kinetics
• Infrared radiation changes molecular electron transfer rates

“The novelty lies in the mechanistic integration,” Seheult emphasizes, “not in any single component.”

What Comes Next

The hypothesis is testable. Future experiments could measure how different infrared wavelengths alter specific Marcus crossing configurations in isolated mitochondrial complexes, or track real-time changes in reorganization energy using advanced spectroscopy.

If validated, the implications extend far beyond biology. Urban planning, architecture, workplace design, and lighting standards may all need reconsideration.

Seheult introduces a new term: photometabolism—solar-driven, non-photosynthetic modulation of core metabolic processes.

It’s a concept that positions sunlight not as a passive environmental factor, but as an active participant in the biochemistry of life itself.

I believe that this hypothesis if true has major implications for the built environment and how we live and the type of light that we require to live, and I believe it’s one of the major reasons why we need to be treating our patients outside.

Sources

• Jeffery et al. (2025) – Longer wavelengths in sunlight penetrating human tissue
• Ma et al. (2018) – Infrared perturbation of charge separation and recombination
• Sanderson et al. (2018) – Inhibitory modulation of cytochrome c oxidase with near-infrared wavelengths
• Dai et al. (2026) – Infrared stimulation of mitochondrial metabolism in deep-sea yeast
• Hayashi et al. (2010) – Water-mediated electron transfer in iron-sulfur bridges
• Marcus and Sutin (1985) – Electron transfer reactions in chemistry

Electrons don’t jump spontaneously between molecules. They require surrounding proteins, water, and lipids to twist into precise configurations—a process that demands energy called “reorganization energy.”

When infrared light hits these structures, it causes them to vibrate. This shifts the probability that molecules will be in the right arrangement for electron transfer to occur.

• If the crossing point is already accessible: Infrared light can push molecules away from optimal configurations, slowing electron transfer
• If the crossing point requires activation: Infrared light can push molecules toward optimal configurations, speeding electron transfer

This explains a puzzling finding from earlier studies: different infrared wavelengths can either increase or decrease mitochondrial activity.

Experiments Confirm the Mechanism

A 2018 study by Ma and colleagues tested this exact principle. Researchers built a custom molecule and used mid-infrared light to excite vibrational modes.

They found infrared light slowed forward electron transfer but accelerated backward transfer—precisely what Marcus theory predicts when nuclear orientations are shifted along energy curves.

IR excitation increases the probability of donor and acceptor energies to remain in degeneracy, resulting in IR-induced electron transfer rate enhancement.

Seheult notes he and co-author Dr. Robert Fosbury spoke with Marcus himself—just months before the scientist passed away at age 102—to discuss their hypothesis.

Deep-Sea Yeast Thrives on Infrared Light—Without Photosynthesis

Perhaps the most striking evidence comes from an unexpected source: yeast living near hydrothermal vents at the bottom of the ocean.

A 2026 study by Dai and colleagues isolated yeast from sediments near a “black smoker” chimney in the central Indian Ocean, more than half a meter from superheated mineral plumes reaching 378°C.

When researchers exposed these yeast cultures to near-infrared light (810–1050 nm) in temperature-controlled conditions, growth increased dramatically compared to dark controls—even though the yeast cannot photosynthesize.

Infrared light outperformed glucose. Adding glucose increased biomass by only 1.3-fold (not statistically significant), while 880-nanometer infrared light produced a threefold increase.

When researchers blocked cytochrome c oxidase (complex IV in mitochondria), near-infrared-stimulated growth dropped by 44%—suggesting the effect operates directly on mitochondrial machinery.

Cold Temperatures, Warm Light

Even more remarkable: infrared light allowed yeast to grow at cooler temperatures where dark controls remained dormant.

At 20°C, yeast exposed to 880-nanometer light grew vigorously while dark controls showed minimal activity. The effective activation energy dropped from 12 kilocalories per mole to just 2 kilocalories per mole.

Infrared light was making up for the cold temperatures by supplying vibrational activation rather than thermal activation.

Proteomics revealed the most upregulated protein after infrared exposure was a mitochondrial ribosomal protein (MRPs8), increased 6.7-fold.

Why Broadband Sunlight May Beat Monochromatic LEDs

Clinical studies using single-wavelength infrared devices have shown benefits—from reducing ICU length of stay to improving muscle strength in COVID-19 patients.

But Seheult’s hypothesis suggests broadband infrared from the sun may be even more effective.

“Sunlight contains a broad spectrum of wavelengths that can interact with many different vibrational modes and electron transfer steps,” he explains, “rather than targeting only one narrow pathway.”

Research from Jeffery’s lab supports this. When comparing monochromatic 850-nanometer light to a 60-watt incandescent bulb (which emits broad-spectrum infrared), the incandescent bulb produced greater improvements in color blindness.

• Monochromatic 850 nm: 9% improvement (head and body), 5% (body only)
• 60W incandescent bulb: 28% improvement, sustained for weeks

The research here aligns with the hypothesis, though direct mechanistic proof in human mitochondria remains to be demonstrated.

The Modern Indoor Environment: A Metabolic Desert?

LED bulbs emit virtually no infrared radiation. Low-emissivity (Low-E) glass windows, designed to improve energy efficiency, block infrared wavelengths.

Seheult measured infrared exposure in his own dining room with windows open: 0.8 watts per square meter.

Step outside under a shade tree with grass reflecting sunlight? 41.9 watts per square meter—more than 50 times higher.

We have set up a situation where outdoors we’re getting plenty of infrared light, versus being indoors where we have Low-E glass blocking it and LED bulbs producing none.

This raises profound questions about whether chronic infrared deficiency could contribute to the rising burden of metabolic diseases, especially among populations spending most of their time indoors.

Seasonal Mortality Patterns Point to Sunlight’s Role

Death rates from heart disease, cancer, stroke, Alzheimer’s, diabetes, and respiratory illness all peak one to three weeks after the shortest day of the year and bottom out after the longest day.

This pattern holds across both infectious and non-infectious causes. The seasonal variation in heart disease deaths alone exceeds total influenza deaths during flu season.

Australia shows the same pattern, but shifted six months—deaths peak in July, their winter. Singapore, 80 miles from the equator with year-round sun, shows no seasonal mortality pattern.

Multiple studies have linked mortality rates to latitude, independent of vitamin D levels, suggesting sunlight itself—particularly its infrared component—plays a direct metabolic role.

Hospitals Are Bringing Patients Outside

Armed with mounting evidence, hospitals worldwide are redesigning care spaces to maximize sunlight exposure.

A $1.5 billion hospital in Footscray, Australia, built ICU beds with direct outdoor access. King’s College Hospital in London invested £2 million to transform its rooftop into a critical care garden where up to six ICU patients can receive treatment surrounded by greenery and natural light.

St. George’s Hospital in London followed suit, creating a neurointensive care rooftop unit. Queen Camilla visited the facility in 2026 to recognize the innovation.

Randomized controlled trials using infrared vests delivering roughly 20–30 watts per square meter (comparable to sitting under a tree) showed 30% reductions in ICU length of stay and improved muscle strength in critically ill COVID-19 patients.

Metabolic Scaling Matches Solar Power Scaling

One of the paper’s most intriguing observations: metabolic rate scales with body mass to the 3/4 power across species from flies to elephants.

Solar power intercepted by an organism also scales to the 3/4 power of mass—nearly identical.

This doesn’t prove causation, but it suggests sunlight could be a universal regulator of metabolic activity across the biosphere, with mitochondria in all organisms tuned to respond to the same infrared wavelengths present in Earth’s solar photon field.

What Makes This Hypothesis Different

Earlier theories proposed infrared light works by activating a photoreceptor in cytochrome c oxidase (complex IV) or by reducing water viscosity around ATP synthase motors.

Seheult’s team doesn’t reject these mechanisms—but argues they’re incomplete.

The Marcus framework explains phenomena earlier models couldn’t: why some infrared wavelengths inhibit rather than enhance mitochondrial activity, why broadband light outperforms monochromatic sources, and why effects persist across vastly different organisms.

The paper is the first to integrate four separate literature streams:

• Mitochondrial electron transfer follows Marcus physics
• Red and near-infrared light alter mitochondrial function
• Water and protein structures affect electron transfer kinetics
• Infrared radiation changes molecular electron transfer rates

“The novelty lies in the mechanistic integration,” Seheult emphasizes, “not in any single component.”

What Comes Next

The hypothesis is testable. Future experiments could measure how different infrared wavelengths alter specific Marcus crossing configurations in isolated mitochondrial complexes, or track real-time changes in reorganization energy using advanced spectroscopy.

If validated, the implications extend far beyond biology. Urban planning, architecture, workplace design, and lighting standards may all need reconsideration.

Seheult introduces a new term: photometabolism—solar-driven, non-photosynthetic modulation of core metabolic processes.

It’s a concept that positions sunlight not as a passive environmental factor, but as an active participant in the biochemistry of life itself.

I believe that this hypothesis if true has major implications for the built environment and how we live and the type of light that we require to live, and I believe it’s one of the major reasons why we need to be treating our patients outside.

Sources

• Jeffery et al. (2025) – Longer wavelengths in sunlight penetrating human tissue
• Ma et al. (2018) – Infrared perturbation of charge separation and recombination
• Sanderson et al. (2018) – Inhibitory modulation of cytochrome c oxidase with near-infrared wavelengths
• Dai et al. (2026) – Infrared stimulation of mitochondrial metabolism in deep-sea yeast
• Hayashi et al. (2010) – Water-mediated electron transfer in iron-sulfur bridges
• Marcus and Sutin (1985) – Electron transfer reactions in chemistry

Electrons don’t jump spontaneously between molecules. They require surrounding proteins, water, and lipids to twist into precise configurations—a process that demands energy called “reorganization energy.”

When infrared light hits these structures, it causes them to vibrate. This shifts the probability that molecules will be in the right arrangement for electron transfer to occur.

• If the crossing point is already accessible: Infrared light can push molecules away from optimal configurations, slowing electron transfer
• If the crossing point requires activation: Infrared light can push molecules toward optimal configurations, speeding electron transfer

This explains a puzzling finding from earlier studies: different infrared wavelengths can either increase or decrease mitochondrial activity.

Experiments Confirm the Mechanism

A 2018 study by Ma and colleagues tested this exact principle. Researchers built a custom molecule and used mid-infrared light to excite vibrational modes.

They found infrared light slowed forward electron transfer but accelerated backward transfer—precisely what Marcus theory predicts when nuclear orientations are shifted along energy curves.

IR excitation increases the probability of donor and acceptor energies to remain in degeneracy, resulting in IR-induced electron transfer rate enhancement.

Seheult notes he and co-author Dr. Robert Fosbury spoke with Marcus himself—just months before the scientist passed away at age 102—to discuss their hypothesis.

Deep-Sea Yeast Thrives on Infrared Light—Without Photosynthesis

Perhaps the most striking evidence comes from an unexpected source: yeast living near hydrothermal vents at the bottom of the ocean.

A 2026 study by Dai and colleagues isolated yeast from sediments near a “black smoker” chimney in the central Indian Ocean, more than half a meter from superheated mineral plumes reaching 378°C.

When researchers exposed these yeast cultures to near-infrared light (810–1050 nm) in temperature-controlled conditions, growth increased dramatically compared to dark controls—even though the yeast cannot photosynthesize.

Infrared light outperformed glucose. Adding glucose increased biomass by only 1.3-fold (not statistically significant), while 880-nanometer infrared light produced a threefold increase.

When researchers blocked cytochrome c oxidase (complex IV in mitochondria), near-infrared-stimulated growth dropped by 44%—suggesting the effect operates directly on mitochondrial machinery.

Cold Temperatures, Warm Light

Even more remarkable: infrared light allowed yeast to grow at cooler temperatures where dark controls remained dormant.

At 20°C, yeast exposed to 880-nanometer light grew vigorously while dark controls showed minimal activity. The effective activation energy dropped from 12 kilocalories per mole to just 2 kilocalories per mole.

Infrared light was making up for the cold temperatures by supplying vibrational activation rather than thermal activation.

Proteomics revealed the most upregulated protein after infrared exposure was a mitochondrial ribosomal protein (MRPs8), increased 6.7-fold.

Why Broadband Sunlight May Beat Monochromatic LEDs

Clinical studies using single-wavelength infrared devices have shown benefits—from reducing ICU length of stay to improving muscle strength in COVID-19 patients.

But Seheult’s hypothesis suggests broadband infrared from the sun may be even more effective.

“Sunlight contains a broad spectrum of wavelengths that can interact with many different vibrational modes and electron transfer steps,” he explains, “rather than targeting only one narrow pathway.”

Research from Jeffery’s lab supports this. When comparing monochromatic 850-nanometer light to a 60-watt incandescent bulb (which emits broad-spectrum infrared), the incandescent bulb produced greater improvements in color blindness.

• Monochromatic 850 nm: 9% improvement (head and body), 5% (body only)
• 60W incandescent bulb: 28% improvement, sustained for weeks

The research here aligns with the hypothesis, though direct mechanistic proof in human mitochondria remains to be demonstrated.

The Modern Indoor Environment: A Metabolic Desert?

LED bulbs emit virtually no infrared radiation. Low-emissivity (Low-E) glass windows, designed to improve energy efficiency, block infrared wavelengths.

Seheult measured infrared exposure in his own dining room with windows open: 0.8 watts per square meter.

Step outside under a shade tree with grass reflecting sunlight? 41.9 watts per square meter—more than 50 times higher.

We have set up a situation where outdoors we’re getting plenty of infrared light, versus being indoors where we have Low-E glass blocking it and LED bulbs producing none.

This raises profound questions about whether chronic infrared deficiency could contribute to the rising burden of metabolic diseases, especially among populations spending most of their time indoors.

Seasonal Mortality Patterns Point to Sunlight’s Role

Death rates from heart disease, cancer, stroke, Alzheimer’s, diabetes, and respiratory illness all peak one to three weeks after the shortest day of the year and bottom out after the longest day.

This pattern holds across both infectious and non-infectious causes. The seasonal variation in heart disease deaths alone exceeds total influenza deaths during flu season.

Australia shows the same pattern, but shifted six months—deaths peak in July, their winter. Singapore, 80 miles from the equator with year-round sun, shows no seasonal mortality pattern.

Multiple studies have linked mortality rates to latitude, independent of vitamin D levels, suggesting sunlight itself—particularly its infrared component—plays a direct metabolic role.

Hospitals Are Bringing Patients Outside

Armed with mounting evidence, hospitals worldwide are redesigning care spaces to maximize sunlight exposure.

A $1.5 billion hospital in Footscray, Australia, built ICU beds with direct outdoor access. King’s College Hospital in London invested £2 million to transform its rooftop into a critical care garden where up to six ICU patients can receive treatment surrounded by greenery and natural light.

St. George’s Hospital in London followed suit, creating a neurointensive care rooftop unit. Queen Camilla visited the facility in 2026 to recognize the innovation.

Randomized controlled trials using infrared vests delivering roughly 20–30 watts per square meter (comparable to sitting under a tree) showed 30% reductions in ICU length of stay and improved muscle strength in critically ill COVID-19 patients.

Metabolic Scaling Matches Solar Power Scaling

One of the paper’s most intriguing observations: metabolic rate scales with body mass to the 3/4 power across species from flies to elephants.

Solar power intercepted by an organism also scales to the 3/4 power of mass—nearly identical.

This doesn’t prove causation, but it suggests sunlight could be a universal regulator of metabolic activity across the biosphere, with mitochondria in all organisms tuned to respond to the same infrared wavelengths present in Earth’s solar photon field.

What Makes This Hypothesis Different

Earlier theories proposed infrared light works by activating a photoreceptor in cytochrome c oxidase (complex IV) or by reducing water viscosity around ATP synthase motors.

Seheult’s team doesn’t reject these mechanisms—but argues they’re incomplete.

The Marcus framework explains phenomena earlier models couldn’t: why some infrared wavelengths inhibit rather than enhance mitochondrial activity, why broadband light outperforms monochromatic sources, and why effects persist across vastly different organisms.

The paper is the first to integrate four separate literature streams:

• Mitochondrial electron transfer follows Marcus physics
• Red and near-infrared light alter mitochondrial function
• Water and protein structures affect electron transfer kinetics
• Infrared radiation changes molecular electron transfer rates

“The novelty lies in the mechanistic integration,” Seheult emphasizes, “not in any single component.”

What Comes Next

The hypothesis is testable. Future experiments could measure how different infrared wavelengths alter specific Marcus crossing configurations in isolated mitochondrial complexes, or track real-time changes in reorganization energy using advanced spectroscopy.

If validated, the implications extend far beyond biology. Urban planning, architecture, workplace design, and lighting standards may all need reconsideration.

Seheult introduces a new term: photometabolism—solar-driven, non-photosynthetic modulation of core metabolic processes.

It’s a concept that positions sunlight not as a passive environmental factor, but as an active participant in the biochemistry of life itself.

I believe that this hypothesis if true has major implications for the built environment and how we live and the type of light that we require to live, and I believe it’s one of the major reasons why we need to be treating our patients outside.

Sources

• Jeffery et al. (2025) – Longer wavelengths in sunlight penetrating human tissue
• Ma et al. (2018) – Infrared perturbation of charge separation and recombination
• Sanderson et al. (2018) – Inhibitory modulation of cytochrome c oxidase with near-infrared wavelengths
• Dai et al. (2026) – Infrared stimulation of mitochondrial metabolism in deep-sea yeast
• Hayashi et al. (2010) – Water-mediated electron transfer in iron-sulfur bridges
• Marcus and Sutin (1985) – Electron transfer reactions in chemistry

To understand how infrared light affects mitochondria, Seheult’s team turned to Marcus electron transfer theory, pioneered by Nobel laureate Rudolph Marcus in the 1960s.

Electrons don’t jump spontaneously between molecules. They require surrounding proteins, water, and lipids to twist into precise configurations—a process that demands energy called “reorganization energy.”

When infrared light hits these structures, it causes them to vibrate. This shifts the probability that molecules will be in the right arrangement for electron transfer to occur.

• If the crossing point is already accessible: Infrared light can push molecules away from optimal configurations, slowing electron transfer
• If the crossing point requires activation: Infrared light can push molecules toward optimal configurations, speeding electron transfer

This explains a puzzling finding from earlier studies: different infrared wavelengths can either increase or decrease mitochondrial activity.

Experiments Confirm the Mechanism

A 2018 study by Ma and colleagues tested this exact principle. Researchers built a custom molecule and used mid-infrared light to excite vibrational modes.

They found infrared light slowed forward electron transfer but accelerated backward transfer—precisely what Marcus theory predicts when nuclear orientations are shifted along energy curves.

IR excitation increases the probability of donor and acceptor energies to remain in degeneracy, resulting in IR-induced electron transfer rate enhancement.

Seheult notes he and co-author Dr. Robert Fosbury spoke with Marcus himself—just months before the scientist passed away at age 102—to discuss their hypothesis.

Deep-Sea Yeast Thrives on Infrared Light—Without Photosynthesis

Perhaps the most striking evidence comes from an unexpected source: yeast living near hydrothermal vents at the bottom of the ocean.

A 2026 study by Dai and colleagues isolated yeast from sediments near a “black smoker” chimney in the central Indian Ocean, more than half a meter from superheated mineral plumes reaching 378°C.

When researchers exposed these yeast cultures to near-infrared light (810–1050 nm) in temperature-controlled conditions, growth increased dramatically compared to dark controls—even though the yeast cannot photosynthesize.

Infrared light outperformed glucose. Adding glucose increased biomass by only 1.3-fold (not statistically significant), while 880-nanometer infrared light produced a threefold increase.

When researchers blocked cytochrome c oxidase (complex IV in mitochondria), near-infrared-stimulated growth dropped by 44%—suggesting the effect operates directly on mitochondrial machinery.

Cold Temperatures, Warm Light

Even more remarkable: infrared light allowed yeast to grow at cooler temperatures where dark controls remained dormant.

At 20°C, yeast exposed to 880-nanometer light grew vigorously while dark controls showed minimal activity. The effective activation energy dropped from 12 kilocalories per mole to just 2 kilocalories per mole.

Infrared light was making up for the cold temperatures by supplying vibrational activation rather than thermal activation.

Proteomics revealed the most upregulated protein after infrared exposure was a mitochondrial ribosomal protein (MRPs8), increased 6.7-fold.

Why Broadband Sunlight May Beat Monochromatic LEDs

Clinical studies using single-wavelength infrared devices have shown benefits—from reducing ICU length of stay to improving muscle strength in COVID-19 patients.

But Seheult’s hypothesis suggests broadband infrared from the sun may be even more effective.

“Sunlight contains a broad spectrum of wavelengths that can interact with many different vibrational modes and electron transfer steps,” he explains, “rather than targeting only one narrow pathway.”

Research from Jeffery’s lab supports this. When comparing monochromatic 850-nanometer light to a 60-watt incandescent bulb (which emits broad-spectrum infrared), the incandescent bulb produced greater improvements in color blindness.

• Monochromatic 850 nm: 9% improvement (head and body), 5% (body only)
• 60W incandescent bulb: 28% improvement, sustained for weeks

The research here aligns with the hypothesis, though direct mechanistic proof in human mitochondria remains to be demonstrated.

The Modern Indoor Environment: A Metabolic Desert?

LED bulbs emit virtually no infrared radiation. Low-emissivity (Low-E) glass windows, designed to improve energy efficiency, block infrared wavelengths.

Seheult measured infrared exposure in his own dining room with windows open: 0.8 watts per square meter.

Step outside under a shade tree with grass reflecting sunlight? 41.9 watts per square meter—more than 50 times higher.

We have set up a situation where outdoors we’re getting plenty of infrared light, versus being indoors where we have Low-E glass blocking it and LED bulbs producing none.

This raises profound questions about whether chronic infrared deficiency could contribute to the rising burden of metabolic diseases, especially among populations spending most of their time indoors.

Seasonal Mortality Patterns Point to Sunlight’s Role

Death rates from heart disease, cancer, stroke, Alzheimer’s, diabetes, and respiratory illness all peak one to three weeks after the shortest day of the year and bottom out after the longest day.

This pattern holds across both infectious and non-infectious causes. The seasonal variation in heart disease deaths alone exceeds total influenza deaths during flu season.

Australia shows the same pattern, but shifted six months—deaths peak in July, their winter. Singapore, 80 miles from the equator with year-round sun, shows no seasonal mortality pattern.

Multiple studies have linked mortality rates to latitude, independent of vitamin D levels, suggesting sunlight itself—particularly its infrared component—plays a direct metabolic role.

Hospitals Are Bringing Patients Outside

Armed with mounting evidence, hospitals worldwide are redesigning care spaces to maximize sunlight exposure.

A $1.5 billion hospital in Footscray, Australia, built ICU beds with direct outdoor access. King’s College Hospital in London invested £2 million to transform its rooftop into a critical care garden where up to six ICU patients can receive treatment surrounded by greenery and natural light.

St. George’s Hospital in London followed suit, creating a neurointensive care rooftop unit. Queen Camilla visited the facility in 2026 to recognize the innovation.

Randomized controlled trials using infrared vests delivering roughly 20–30 watts per square meter (comparable to sitting under a tree) showed 30% reductions in ICU length of stay and improved muscle strength in critically ill COVID-19 patients.

Metabolic Scaling Matches Solar Power Scaling

One of the paper’s most intriguing observations: metabolic rate scales with body mass to the 3/4 power across species from flies to elephants.

Solar power intercepted by an organism also scales to the 3/4 power of mass—nearly identical.

This doesn’t prove causation, but it suggests sunlight could be a universal regulator of metabolic activity across the biosphere, with mitochondria in all organisms tuned to respond to the same infrared wavelengths present in Earth’s solar photon field.

What Makes This Hypothesis Different

Earlier theories proposed infrared light works by activating a photoreceptor in cytochrome c oxidase (complex IV) or by reducing water viscosity around ATP synthase motors.

Seheult’s team doesn’t reject these mechanisms—but argues they’re incomplete.

The Marcus framework explains phenomena earlier models couldn’t: why some infrared wavelengths inhibit rather than enhance mitochondrial activity, why broadband light outperforms monochromatic sources, and why effects persist across vastly different organisms.

The paper is the first to integrate four separate literature streams:

• Mitochondrial electron transfer follows Marcus physics
• Red and near-infrared light alter mitochondrial function
• Water and protein structures affect electron transfer kinetics
• Infrared radiation changes molecular electron transfer rates

“The novelty lies in the mechanistic integration,” Seheult emphasizes, “not in any single component.”

What Comes Next

The hypothesis is testable. Future experiments could measure how different infrared wavelengths alter specific Marcus crossing configurations in isolated mitochondrial complexes, or track real-time changes in reorganization energy using advanced spectroscopy.

If validated, the implications extend far beyond biology. Urban planning, architecture, workplace design, and lighting standards may all need reconsideration.

Seheult introduces a new term: photometabolism—solar-driven, non-photosynthetic modulation of core metabolic processes.

It’s a concept that positions sunlight not as a passive environmental factor, but as an active participant in the biochemistry of life itself.

I believe that this hypothesis if true has major implications for the built environment and how we live and the type of light that we require to live, and I believe it’s one of the major reasons why we need to be treating our patients outside.

Sources

• Jeffery et al. (2025) – Longer wavelengths in sunlight penetrating human tissue
• Ma et al. (2018) – Infrared perturbation of charge separation and recombination
• Sanderson et al. (2018) – Inhibitory modulation of cytochrome c oxidase with near-infrared wavelengths
• Dai et al. (2026) – Infrared stimulation of mitochondrial metabolism in deep-sea yeast
• Hayashi et al. (2010) – Water-mediated electron transfer in iron-sulfur bridges
• Marcus and Sutin (1985) – Electron transfer reactions in chemistry

To understand how infrared light affects mitochondria, Seheult’s team turned to Marcus electron transfer theory, pioneered by Nobel laureate Rudolph Marcus in the 1960s.

Electrons don’t jump spontaneously between molecules. They require surrounding proteins, water, and lipids to twist into precise configurations—a process that demands energy called “reorganization energy.”

When infrared light hits these structures, it causes them to vibrate. This shifts the probability that molecules will be in the right arrangement for electron transfer to occur.

• If the crossing point is already accessible: Infrared light can push molecules away from optimal configurations, slowing electron transfer
• If the crossing point requires activation: Infrared light can push molecules toward optimal configurations, speeding electron transfer

This explains a puzzling finding from earlier studies: different infrared wavelengths can either increase or decrease mitochondrial activity.

Experiments Confirm the Mechanism

A 2018 study by Ma and colleagues tested this exact principle. Researchers built a custom molecule and used mid-infrared light to excite vibrational modes.

They found infrared light slowed forward electron transfer but accelerated backward transfer—precisely what Marcus theory predicts when nuclear orientations are shifted along energy curves.

IR excitation increases the probability of donor and acceptor energies to remain in degeneracy, resulting in IR-induced electron transfer rate enhancement.

Seheult notes he and co-author Dr. Robert Fosbury spoke with Marcus himself—just months before the scientist passed away at age 102—to discuss their hypothesis.

Deep-Sea Yeast Thrives on Infrared Light—Without Photosynthesis

Perhaps the most striking evidence comes from an unexpected source: yeast living near hydrothermal vents at the bottom of the ocean.

A 2026 study by Dai and colleagues isolated yeast from sediments near a “black smoker” chimney in the central Indian Ocean, more than half a meter from superheated mineral plumes reaching 378°C.

When researchers exposed these yeast cultures to near-infrared light (810–1050 nm) in temperature-controlled conditions, growth increased dramatically compared to dark controls—even though the yeast cannot photosynthesize.

Infrared light outperformed glucose. Adding glucose increased biomass by only 1.3-fold (not statistically significant), while 880-nanometer infrared light produced a threefold increase.

When researchers blocked cytochrome c oxidase (complex IV in mitochondria), near-infrared-stimulated growth dropped by 44%—suggesting the effect operates directly on mitochondrial machinery.

Cold Temperatures, Warm Light

Even more remarkable: infrared light allowed yeast to grow at cooler temperatures where dark controls remained dormant.

At 20°C, yeast exposed to 880-nanometer light grew vigorously while dark controls showed minimal activity. The effective activation energy dropped from 12 kilocalories per mole to just 2 kilocalories per mole.

Infrared light was making up for the cold temperatures by supplying vibrational activation rather than thermal activation.

Proteomics revealed the most upregulated protein after infrared exposure was a mitochondrial ribosomal protein (MRPs8), increased 6.7-fold.

Why Broadband Sunlight May Beat Monochromatic LEDs

Clinical studies using single-wavelength infrared devices have shown benefits—from reducing ICU length of stay to improving muscle strength in COVID-19 patients.

But Seheult’s hypothesis suggests broadband infrared from the sun may be even more effective.

“Sunlight contains a broad spectrum of wavelengths that can interact with many different vibrational modes and electron transfer steps,” he explains, “rather than targeting only one narrow pathway.”

Research from Jeffery’s lab supports this. When comparing monochromatic 850-nanometer light to a 60-watt incandescent bulb (which emits broad-spectrum infrared), the incandescent bulb produced greater improvements in color blindness.

• Monochromatic 850 nm: 9% improvement (head and body), 5% (body only)
• 60W incandescent bulb: 28% improvement, sustained for weeks

The research here aligns with the hypothesis, though direct mechanistic proof in human mitochondria remains to be demonstrated.

The Modern Indoor Environment: A Metabolic Desert?

LED bulbs emit virtually no infrared radiation. Low-emissivity (Low-E) glass windows, designed to improve energy efficiency, block infrared wavelengths.

Seheult measured infrared exposure in his own dining room with windows open: 0.8 watts per square meter.

Step outside under a shade tree with grass reflecting sunlight? 41.9 watts per square meter—more than 50 times higher.

We have set up a situation where outdoors we’re getting plenty of infrared light, versus being indoors where we have Low-E glass blocking it and LED bulbs producing none.

This raises profound questions about whether chronic infrared deficiency could contribute to the rising burden of metabolic diseases, especially among populations spending most of their time indoors.

Seasonal Mortality Patterns Point to Sunlight’s Role

Death rates from heart disease, cancer, stroke, Alzheimer’s, diabetes, and respiratory illness all peak one to three weeks after the shortest day of the year and bottom out after the longest day.

This pattern holds across both infectious and non-infectious causes. The seasonal variation in heart disease deaths alone exceeds total influenza deaths during flu season.

Australia shows the same pattern, but shifted six months—deaths peak in July, their winter. Singapore, 80 miles from the equator with year-round sun, shows no seasonal mortality pattern.

Multiple studies have linked mortality rates to latitude, independent of vitamin D levels, suggesting sunlight itself—particularly its infrared component—plays a direct metabolic role.

Hospitals Are Bringing Patients Outside

Armed with mounting evidence, hospitals worldwide are redesigning care spaces to maximize sunlight exposure.

A $1.5 billion hospital in Footscray, Australia, built ICU beds with direct outdoor access. King’s College Hospital in London invested £2 million to transform its rooftop into a critical care garden where up to six ICU patients can receive treatment surrounded by greenery and natural light.

St. George’s Hospital in London followed suit, creating a neurointensive care rooftop unit. Queen Camilla visited the facility in 2026 to recognize the innovation.

Randomized controlled trials using infrared vests delivering roughly 20–30 watts per square meter (comparable to sitting under a tree) showed 30% reductions in ICU length of stay and improved muscle strength in critically ill COVID-19 patients.

Metabolic Scaling Matches Solar Power Scaling

One of the paper’s most intriguing observations: metabolic rate scales with body mass to the 3/4 power across species from flies to elephants.

Solar power intercepted by an organism also scales to the 3/4 power of mass—nearly identical.

This doesn’t prove causation, but it suggests sunlight could be a universal regulator of metabolic activity across the biosphere, with mitochondria in all organisms tuned to respond to the same infrared wavelengths present in Earth’s solar photon field.

What Makes This Hypothesis Different

Earlier theories proposed infrared light works by activating a photoreceptor in cytochrome c oxidase (complex IV) or by reducing water viscosity around ATP synthase motors.

Seheult’s team doesn’t reject these mechanisms—but argues they’re incomplete.

The Marcus framework explains phenomena earlier models couldn’t: why some infrared wavelengths inhibit rather than enhance mitochondrial activity, why broadband light outperforms monochromatic sources, and why effects persist across vastly different organisms.

The paper is the first to integrate four separate literature streams:

• Mitochondrial electron transfer follows Marcus physics
• Red and near-infrared light alter mitochondrial function
• Water and protein structures affect electron transfer kinetics
• Infrared radiation changes molecular electron transfer rates

“The novelty lies in the mechanistic integration,” Seheult emphasizes, “not in any single component.”

What Comes Next

The hypothesis is testable. Future experiments could measure how different infrared wavelengths alter specific Marcus crossing configurations in isolated mitochondrial complexes, or track real-time changes in reorganization energy using advanced spectroscopy.

If validated, the implications extend far beyond biology. Urban planning, architecture, workplace design, and lighting standards may all need reconsideration.

Seheult introduces a new term: photometabolism—solar-driven, non-photosynthetic modulation of core metabolic processes.

It’s a concept that positions sunlight not as a passive environmental factor, but as an active participant in the biochemistry of life itself.

I believe that this hypothesis if true has major implications for the built environment and how we live and the type of light that we require to live, and I believe it’s one of the major reasons why we need to be treating our patients outside.

Sources

• Jeffery et al. (2025) – Longer wavelengths in sunlight penetrating human tissue
• Ma et al. (2018) – Infrared perturbation of charge separation and recombination
• Sanderson et al. (2018) – Inhibitory modulation of cytochrome c oxidase with near-infrared wavelengths
• Dai et al. (2026) – Infrared stimulation of mitochondrial metabolism in deep-sea yeast
• Hayashi et al. (2010) – Water-mediated electron transfer in iron-sulfur bridges
• Marcus and Sutin (1985) – Electron transfer reactions in chemistry

Marcus Electron Transfer: The Physics Behind the Biology

To understand how infrared light affects mitochondria, Seheult’s team turned to Marcus electron transfer theory, pioneered by Nobel laureate Rudolph Marcus in the 1960s.

Electrons don’t jump spontaneously between molecules. They require surrounding proteins, water, and lipids to twist into precise configurations—a process that demands energy called “reorganization energy.”

When infrared light hits these structures, it causes them to vibrate. This shifts the probability that molecules will be in the right arrangement for electron transfer to occur.

• If the crossing point is already accessible: Infrared light can push molecules away from optimal configurations, slowing electron transfer
• If the crossing point requires activation: Infrared light can push molecules toward optimal configurations, speeding electron transfer

This explains a puzzling finding from earlier studies: different infrared wavelengths can either increase or decrease mitochondrial activity.

Experiments Confirm the Mechanism

A 2018 study by Ma and colleagues tested this exact principle. Researchers built a custom molecule and used mid-infrared light to excite vibrational modes.

They found infrared light slowed forward electron transfer but accelerated backward transfer—precisely what Marcus theory predicts when nuclear orientations are shifted along energy curves.

IR excitation increases the probability of donor and acceptor energies to remain in degeneracy, resulting in IR-induced electron transfer rate enhancement.

Seheult notes he and co-author Dr. Robert Fosbury spoke with Marcus himself—just months before the scientist passed away at age 102—to discuss their hypothesis.

Deep-Sea Yeast Thrives on Infrared Light—Without Photosynthesis

Perhaps the most striking evidence comes from an unexpected source: yeast living near hydrothermal vents at the bottom of the ocean.

A 2026 study by Dai and colleagues isolated yeast from sediments near a “black smoker” chimney in the central Indian Ocean, more than half a meter from superheated mineral plumes reaching 378°C.

When researchers exposed these yeast cultures to near-infrared light (810–1050 nm) in temperature-controlled conditions, growth increased dramatically compared to dark controls—even though the yeast cannot photosynthesize.

Infrared light outperformed glucose. Adding glucose increased biomass by only 1.3-fold (not statistically significant), while 880-nanometer infrared light produced a threefold increase.

When researchers blocked cytochrome c oxidase (complex IV in mitochondria), near-infrared-stimulated growth dropped by 44%—suggesting the effect operates directly on mitochondrial machinery.

Cold Temperatures, Warm Light

Even more remarkable: infrared light allowed yeast to grow at cooler temperatures where dark controls remained dormant.

At 20°C, yeast exposed to 880-nanometer light grew vigorously while dark controls showed minimal activity. The effective activation energy dropped from 12 kilocalories per mole to just 2 kilocalories per mole.

Infrared light was making up for the cold temperatures by supplying vibrational activation rather than thermal activation.

Proteomics revealed the most upregulated protein after infrared exposure was a mitochondrial ribosomal protein (MRPs8), increased 6.7-fold.

Why Broadband Sunlight May Beat Monochromatic LEDs

Clinical studies using single-wavelength infrared devices have shown benefits—from reducing ICU length of stay to improving muscle strength in COVID-19 patients.

But Seheult’s hypothesis suggests broadband infrared from the sun may be even more effective.

“Sunlight contains a broad spectrum of wavelengths that can interact with many different vibrational modes and electron transfer steps,” he explains, “rather than targeting only one narrow pathway.”

Research from Jeffery’s lab supports this. When comparing monochromatic 850-nanometer light to a 60-watt incandescent bulb (which emits broad-spectrum infrared), the incandescent bulb produced greater improvements in color blindness.

• Monochromatic 850 nm: 9% improvement (head and body), 5% (body only)
• 60W incandescent bulb: 28% improvement, sustained for weeks

The research here aligns with the hypothesis, though direct mechanistic proof in human mitochondria remains to be demonstrated.

The Modern Indoor Environment: A Metabolic Desert?

LED bulbs emit virtually no infrared radiation. Low-emissivity (Low-E) glass windows, designed to improve energy efficiency, block infrared wavelengths.

Seheult measured infrared exposure in his own dining room with windows open: 0.8 watts per square meter.

Step outside under a shade tree with grass reflecting sunlight? 41.9 watts per square meter—more than 50 times higher.

We have set up a situation where outdoors we’re getting plenty of infrared light, versus being indoors where we have Low-E glass blocking it and LED bulbs producing none.

This raises profound questions about whether chronic infrared deficiency could contribute to the rising burden of metabolic diseases, especially among populations spending most of their time indoors.

Seasonal Mortality Patterns Point to Sunlight’s Role

Death rates from heart disease, cancer, stroke, Alzheimer’s, diabetes, and respiratory illness all peak one to three weeks after the shortest day of the year and bottom out after the longest day.

This pattern holds across both infectious and non-infectious causes. The seasonal variation in heart disease deaths alone exceeds total influenza deaths during flu season.

Australia shows the same pattern, but shifted six months—deaths peak in July, their winter. Singapore, 80 miles from the equator with year-round sun, shows no seasonal mortality pattern.

Multiple studies have linked mortality rates to latitude, independent of vitamin D levels, suggesting sunlight itself—particularly its infrared component—plays a direct metabolic role.

Hospitals Are Bringing Patients Outside

Armed with mounting evidence, hospitals worldwide are redesigning care spaces to maximize sunlight exposure.

A $1.5 billion hospital in Footscray, Australia, built ICU beds with direct outdoor access. King’s College Hospital in London invested £2 million to transform its rooftop into a critical care garden where up to six ICU patients can receive treatment surrounded by greenery and natural light.

St. George’s Hospital in London followed suit, creating a neurointensive care rooftop unit. Queen Camilla visited the facility in 2026 to recognize the innovation.

Randomized controlled trials using infrared vests delivering roughly 20–30 watts per square meter (comparable to sitting under a tree) showed 30% reductions in ICU length of stay and improved muscle strength in critically ill COVID-19 patients.

Metabolic Scaling Matches Solar Power Scaling

One of the paper’s most intriguing observations: metabolic rate scales with body mass to the 3/4 power across species from flies to elephants.

Solar power intercepted by an organism also scales to the 3/4 power of mass—nearly identical.

This doesn’t prove causation, but it suggests sunlight could be a universal regulator of metabolic activity across the biosphere, with mitochondria in all organisms tuned to respond to the same infrared wavelengths present in Earth’s solar photon field.

What Makes This Hypothesis Different

Earlier theories proposed infrared light works by activating a photoreceptor in cytochrome c oxidase (complex IV) or by reducing water viscosity around ATP synthase motors.

Seheult’s team doesn’t reject these mechanisms—but argues they’re incomplete.

The Marcus framework explains phenomena earlier models couldn’t: why some infrared wavelengths inhibit rather than enhance mitochondrial activity, why broadband light outperforms monochromatic sources, and why effects persist across vastly different organisms.

The paper is the first to integrate four separate literature streams:

• Mitochondrial electron transfer follows Marcus physics
• Red and near-infrared light alter mitochondrial function
• Water and protein structures affect electron transfer kinetics
• Infrared radiation changes molecular electron transfer rates

“The novelty lies in the mechanistic integration,” Seheult emphasizes, “not in any single component.”

What Comes Next

The hypothesis is testable. Future experiments could measure how different infrared wavelengths alter specific Marcus crossing configurations in isolated mitochondrial complexes, or track real-time changes in reorganization energy using advanced spectroscopy.

If validated, the implications extend far beyond biology. Urban planning, architecture, workplace design, and lighting standards may all need reconsideration.

Seheult introduces a new term: photometabolism—solar-driven, non-photosynthetic modulation of core metabolic processes.

It’s a concept that positions sunlight not as a passive environmental factor, but as an active participant in the biochemistry of life itself.

I believe that this hypothesis if true has major implications for the built environment and how we live and the type of light that we require to live, and I believe it’s one of the major reasons why we need to be treating our patients outside.

Sources

• Jeffery et al. (2025) – Longer wavelengths in sunlight penetrating human tissue
• Ma et al. (2018) – Infrared perturbation of charge separation and recombination
• Sanderson et al. (2018) – Inhibitory modulation of cytochrome c oxidase with near-infrared wavelengths
• Dai et al. (2026) – Infrared stimulation of mitochondrial metabolism in deep-sea yeast
• Hayashi et al. (2010) – Water-mediated electron transfer in iron-sulfur bridges
• Marcus and Sutin (1985) – Electron transfer reactions in chemistry

Marcus Electron Transfer: The Physics Behind the Biology

To understand how infrared light affects mitochondria, Seheult’s team turned to Marcus electron transfer theory, pioneered by Nobel laureate Rudolph Marcus in the 1960s.

Electrons don’t jump spontaneously between molecules. They require surrounding proteins, water, and lipids to twist into precise configurations—a process that demands energy called “reorganization energy.”

When infrared light hits these structures, it causes them to vibrate. This shifts the probability that molecules will be in the right arrangement for electron transfer to occur.

• If the crossing point is already accessible: Infrared light can push molecules away from optimal configurations, slowing electron transfer
• If the crossing point requires activation: Infrared light can push molecules toward optimal configurations, speeding electron transfer

This explains a puzzling finding from earlier studies: different infrared wavelengths can either increase or decrease mitochondrial activity.

Experiments Confirm the Mechanism

A 2018 study by Ma and colleagues tested this exact principle. Researchers built a custom molecule and used mid-infrared light to excite vibrational modes.

They found infrared light slowed forward electron transfer but accelerated backward transfer—precisely what Marcus theory predicts when nuclear orientations are shifted along energy curves.

IR excitation increases the probability of donor and acceptor energies to remain in degeneracy, resulting in IR-induced electron transfer rate enhancement.

Seheult notes he and co-author Dr. Robert Fosbury spoke with Marcus himself—just months before the scientist passed away at age 102—to discuss their hypothesis.

Deep-Sea Yeast Thrives on Infrared Light—Without Photosynthesis

Perhaps the most striking evidence comes from an unexpected source: yeast living near hydrothermal vents at the bottom of the ocean.

A 2026 study by Dai and colleagues isolated yeast from sediments near a “black smoker” chimney in the central Indian Ocean, more than half a meter from superheated mineral plumes reaching 378°C.

When researchers exposed these yeast cultures to near-infrared light (810–1050 nm) in temperature-controlled conditions, growth increased dramatically compared to dark controls—even though the yeast cannot photosynthesize.

Infrared light outperformed glucose. Adding glucose increased biomass by only 1.3-fold (not statistically significant), while 880-nanometer infrared light produced a threefold increase.

When researchers blocked cytochrome c oxidase (complex IV in mitochondria), near-infrared-stimulated growth dropped by 44%—suggesting the effect operates directly on mitochondrial machinery.

Cold Temperatures, Warm Light

Even more remarkable: infrared light allowed yeast to grow at cooler temperatures where dark controls remained dormant.

At 20°C, yeast exposed to 880-nanometer light grew vigorously while dark controls showed minimal activity. The effective activation energy dropped from 12 kilocalories per mole to just 2 kilocalories per mole.

Infrared light was making up for the cold temperatures by supplying vibrational activation rather than thermal activation.

Proteomics revealed the most upregulated protein after infrared exposure was a mitochondrial ribosomal protein (MRPs8), increased 6.7-fold.

Why Broadband Sunlight May Beat Monochromatic LEDs

Clinical studies using single-wavelength infrared devices have shown benefits—from reducing ICU length of stay to improving muscle strength in COVID-19 patients.

But Seheult’s hypothesis suggests broadband infrared from the sun may be even more effective.

“Sunlight contains a broad spectrum of wavelengths that can interact with many different vibrational modes and electron transfer steps,” he explains, “rather than targeting only one narrow pathway.”

Research from Jeffery’s lab supports this. When comparing monochromatic 850-nanometer light to a 60-watt incandescent bulb (which emits broad-spectrum infrared), the incandescent bulb produced greater improvements in color blindness.

• Monochromatic 850 nm: 9% improvement (head and body), 5% (body only)
• 60W incandescent bulb: 28% improvement, sustained for weeks

The research here aligns with the hypothesis, though direct mechanistic proof in human mitochondria remains to be demonstrated.

The Modern Indoor Environment: A Metabolic Desert?

LED bulbs emit virtually no infrared radiation. Low-emissivity (Low-E) glass windows, designed to improve energy efficiency, block infrared wavelengths.

Seheult measured infrared exposure in his own dining room with windows open: 0.8 watts per square meter.

Step outside under a shade tree with grass reflecting sunlight? 41.9 watts per square meter—more than 50 times higher.

We have set up a situation where outdoors we’re getting plenty of infrared light, versus being indoors where we have Low-E glass blocking it and LED bulbs producing none.

This raises profound questions about whether chronic infrared deficiency could contribute to the rising burden of metabolic diseases, especially among populations spending most of their time indoors.

Seasonal Mortality Patterns Point to Sunlight’s Role

Death rates from heart disease, cancer, stroke, Alzheimer’s, diabetes, and respiratory illness all peak one to three weeks after the shortest day of the year and bottom out after the longest day.

This pattern holds across both infectious and non-infectious causes. The seasonal variation in heart disease deaths alone exceeds total influenza deaths during flu season.

Australia shows the same pattern, but shifted six months—deaths peak in July, their winter. Singapore, 80 miles from the equator with year-round sun, shows no seasonal mortality pattern.

Multiple studies have linked mortality rates to latitude, independent of vitamin D levels, suggesting sunlight itself—particularly its infrared component—plays a direct metabolic role.

Hospitals Are Bringing Patients Outside

Armed with mounting evidence, hospitals worldwide are redesigning care spaces to maximize sunlight exposure.

A $1.5 billion hospital in Footscray, Australia, built ICU beds with direct outdoor access. King’s College Hospital in London invested £2 million to transform its rooftop into a critical care garden where up to six ICU patients can receive treatment surrounded by greenery and natural light.

St. George’s Hospital in London followed suit, creating a neurointensive care rooftop unit. Queen Camilla visited the facility in 2026 to recognize the innovation.

Randomized controlled trials using infrared vests delivering roughly 20–30 watts per square meter (comparable to sitting under a tree) showed 30% reductions in ICU length of stay and improved muscle strength in critically ill COVID-19 patients.

Metabolic Scaling Matches Solar Power Scaling

One of the paper’s most intriguing observations: metabolic rate scales with body mass to the 3/4 power across species from flies to elephants.

Solar power intercepted by an organism also scales to the 3/4 power of mass—nearly identical.

This doesn’t prove causation, but it suggests sunlight could be a universal regulator of metabolic activity across the biosphere, with mitochondria in all organisms tuned to respond to the same infrared wavelengths present in Earth’s solar photon field.

What Makes This Hypothesis Different

Earlier theories proposed infrared light works by activating a photoreceptor in cytochrome c oxidase (complex IV) or by reducing water viscosity around ATP synthase motors.

Seheult’s team doesn’t reject these mechanisms—but argues they’re incomplete.

The Marcus framework explains phenomena earlier models couldn’t: why some infrared wavelengths inhibit rather than enhance mitochondrial activity, why broadband light outperforms monochromatic sources, and why effects persist across vastly different organisms.

The paper is the first to integrate four separate literature streams:

• Mitochondrial electron transfer follows Marcus physics
• Red and near-infrared light alter mitochondrial function
• Water and protein structures affect electron transfer kinetics
• Infrared radiation changes molecular electron transfer rates

“The novelty lies in the mechanistic integration,” Seheult emphasizes, “not in any single component.”

What Comes Next

The hypothesis is testable. Future experiments could measure how different infrared wavelengths alter specific Marcus crossing configurations in isolated mitochondrial complexes, or track real-time changes in reorganization energy using advanced spectroscopy.

If validated, the implications extend far beyond biology. Urban planning, architecture, workplace design, and lighting standards may all need reconsideration.

Seheult introduces a new term: photometabolism—solar-driven, non-photosynthetic modulation of core metabolic processes.

It’s a concept that positions sunlight not as a passive environmental factor, but as an active participant in the biochemistry of life itself.

I believe that this hypothesis if true has major implications for the built environment and how we live and the type of light that we require to live, and I believe it’s one of the major reasons why we need to be treating our patients outside.

Sources

• Jeffery et al. (2025) – Longer wavelengths in sunlight penetrating human tissue
• Ma et al. (2018) – Infrared perturbation of charge separation and recombination
• Sanderson et al. (2018) – Inhibitory modulation of cytochrome c oxidase with near-infrared wavelengths
• Dai et al. (2026) – Infrared stimulation of mitochondrial metabolism in deep-sea yeast
• Hayashi et al. (2010) – Water-mediated electron transfer in iron-sulfur bridges
• Marcus and Sutin (1985) – Electron transfer reactions in chemistry

The result? A unique atmospheric window that allows these photons to reach Earth’s surface in abundance—and potentially interact with living cells in ways artificial light cannot replicate.

Marcus Electron Transfer: The Physics Behind the Biology

To understand how infrared light affects mitochondria, Seheult’s team turned to Marcus electron transfer theory, pioneered by Nobel laureate Rudolph Marcus in the 1960s.

Electrons don’t jump spontaneously between molecules. They require surrounding proteins, water, and lipids to twist into precise configurations—a process that demands energy called “reorganization energy.”

When infrared light hits these structures, it causes them to vibrate. This shifts the probability that molecules will be in the right arrangement for electron transfer to occur.

• If the crossing point is already accessible: Infrared light can push molecules away from optimal configurations, slowing electron transfer
• If the crossing point requires activation: Infrared light can push molecules toward optimal configurations, speeding electron transfer

This explains a puzzling finding from earlier studies: different infrared wavelengths can either increase or decrease mitochondrial activity.

Experiments Confirm the Mechanism

A 2018 study by Ma and colleagues tested this exact principle. Researchers built a custom molecule and used mid-infrared light to excite vibrational modes.

They found infrared light slowed forward electron transfer but accelerated backward transfer—precisely what Marcus theory predicts when nuclear orientations are shifted along energy curves.

IR excitation increases the probability of donor and acceptor energies to remain in degeneracy, resulting in IR-induced electron transfer rate enhancement.

Seheult notes he and co-author Dr. Robert Fosbury spoke with Marcus himself—just months before the scientist passed away at age 102—to discuss their hypothesis.

Deep-Sea Yeast Thrives on Infrared Light—Without Photosynthesis

Perhaps the most striking evidence comes from an unexpected source: yeast living near hydrothermal vents at the bottom of the ocean.

A 2026 study by Dai and colleagues isolated yeast from sediments near a “black smoker” chimney in the central Indian Ocean, more than half a meter from superheated mineral plumes reaching 378°C.

When researchers exposed these yeast cultures to near-infrared light (810–1050 nm) in temperature-controlled conditions, growth increased dramatically compared to dark controls—even though the yeast cannot photosynthesize.

Infrared light outperformed glucose. Adding glucose increased biomass by only 1.3-fold (not statistically significant), while 880-nanometer infrared light produced a threefold increase.

When researchers blocked cytochrome c oxidase (complex IV in mitochondria), near-infrared-stimulated growth dropped by 44%—suggesting the effect operates directly on mitochondrial machinery.

Cold Temperatures, Warm Light

Even more remarkable: infrared light allowed yeast to grow at cooler temperatures where dark controls remained dormant.

At 20°C, yeast exposed to 880-nanometer light grew vigorously while dark controls showed minimal activity. The effective activation energy dropped from 12 kilocalories per mole to just 2 kilocalories per mole.

Infrared light was making up for the cold temperatures by supplying vibrational activation rather than thermal activation.

Proteomics revealed the most upregulated protein after infrared exposure was a mitochondrial ribosomal protein (MRPs8), increased 6.7-fold.

Why Broadband Sunlight May Beat Monochromatic LEDs

Clinical studies using single-wavelength infrared devices have shown benefits—from reducing ICU length of stay to improving muscle strength in COVID-19 patients.

But Seheult’s hypothesis suggests broadband infrared from the sun may be even more effective.

“Sunlight contains a broad spectrum of wavelengths that can interact with many different vibrational modes and electron transfer steps,” he explains, “rather than targeting only one narrow pathway.”

Research from Jeffery’s lab supports this. When comparing monochromatic 850-nanometer light to a 60-watt incandescent bulb (which emits broad-spectrum infrared), the incandescent bulb produced greater improvements in color blindness.

• Monochromatic 850 nm: 9% improvement (head and body), 5% (body only)
• 60W incandescent bulb: 28% improvement, sustained for weeks

The research here aligns with the hypothesis, though direct mechanistic proof in human mitochondria remains to be demonstrated.

The Modern Indoor Environment: A Metabolic Desert?

LED bulbs emit virtually no infrared radiation. Low-emissivity (Low-E) glass windows, designed to improve energy efficiency, block infrared wavelengths.

Seheult measured infrared exposure in his own dining room with windows open: 0.8 watts per square meter.

Step outside under a shade tree with grass reflecting sunlight? 41.9 watts per square meter—more than 50 times higher.

We have set up a situation where outdoors we’re getting plenty of infrared light, versus being indoors where we have Low-E glass blocking it and LED bulbs producing none.

This raises profound questions about whether chronic infrared deficiency could contribute to the rising burden of metabolic diseases, especially among populations spending most of their time indoors.

Seasonal Mortality Patterns Point to Sunlight’s Role

Death rates from heart disease, cancer, stroke, Alzheimer’s, diabetes, and respiratory illness all peak one to three weeks after the shortest day of the year and bottom out after the longest day.

This pattern holds across both infectious and non-infectious causes. The seasonal variation in heart disease deaths alone exceeds total influenza deaths during flu season.

Australia shows the same pattern, but shifted six months—deaths peak in July, their winter. Singapore, 80 miles from the equator with year-round sun, shows no seasonal mortality pattern.

Multiple studies have linked mortality rates to latitude, independent of vitamin D levels, suggesting sunlight itself—particularly its infrared component—plays a direct metabolic role.

Hospitals Are Bringing Patients Outside

Armed with mounting evidence, hospitals worldwide are redesigning care spaces to maximize sunlight exposure.

A $1.5 billion hospital in Footscray, Australia, built ICU beds with direct outdoor access. King’s College Hospital in London invested £2 million to transform its rooftop into a critical care garden where up to six ICU patients can receive treatment surrounded by greenery and natural light.

St. George’s Hospital in London followed suit, creating a neurointensive care rooftop unit. Queen Camilla visited the facility in 2026 to recognize the innovation.

Randomized controlled trials using infrared vests delivering roughly 20–30 watts per square meter (comparable to sitting under a tree) showed 30% reductions in ICU length of stay and improved muscle strength in critically ill COVID-19 patients.

Metabolic Scaling Matches Solar Power Scaling

One of the paper’s most intriguing observations: metabolic rate scales with body mass to the 3/4 power across species from flies to elephants.

Solar power intercepted by an organism also scales to the 3/4 power of mass—nearly identical.

This doesn’t prove causation, but it suggests sunlight could be a universal regulator of metabolic activity across the biosphere, with mitochondria in all organisms tuned to respond to the same infrared wavelengths present in Earth’s solar photon field.

What Makes This Hypothesis Different

Earlier theories proposed infrared light works by activating a photoreceptor in cytochrome c oxidase (complex IV) or by reducing water viscosity around ATP synthase motors.

Seheult’s team doesn’t reject these mechanisms—but argues they’re incomplete.

The Marcus framework explains phenomena earlier models couldn’t: why some infrared wavelengths inhibit rather than enhance mitochondrial activity, why broadband light outperforms monochromatic sources, and why effects persist across vastly different organisms.

The paper is the first to integrate four separate literature streams:

• Mitochondrial electron transfer follows Marcus physics
• Red and near-infrared light alter mitochondrial function
• Water and protein structures affect electron transfer kinetics
• Infrared radiation changes molecular electron transfer rates

“The novelty lies in the mechanistic integration,” Seheult emphasizes, “not in any single component.”

What Comes Next

The hypothesis is testable. Future experiments could measure how different infrared wavelengths alter specific Marcus crossing configurations in isolated mitochondrial complexes, or track real-time changes in reorganization energy using advanced spectroscopy.

If validated, the implications extend far beyond biology. Urban planning, architecture, workplace design, and lighting standards may all need reconsideration.

Seheult introduces a new term: photometabolism—solar-driven, non-photosynthetic modulation of core metabolic processes.

It’s a concept that positions sunlight not as a passive environmental factor, but as an active participant in the biochemistry of life itself.

I believe that this hypothesis if true has major implications for the built environment and how we live and the type of light that we require to live, and I believe it’s one of the major reasons why we need to be treating our patients outside.

Sources

• Jeffery et al. (2025) – Longer wavelengths in sunlight penetrating human tissue
• Ma et al. (2018) – Infrared perturbation of charge separation and recombination
• Sanderson et al. (2018) – Inhibitory modulation of cytochrome c oxidase with near-infrared wavelengths
• Dai et al. (2026) – Infrared stimulation of mitochondrial metabolism in deep-sea yeast
• Hayashi et al. (2010) – Water-mediated electron transfer in iron-sulfur bridges
• Marcus and Sutin (1985) – Electron transfer reactions in chemistry

The result? A unique atmospheric window that allows these photons to reach Earth’s surface in abundance—and potentially interact with living cells in ways artificial light cannot replicate.

Marcus Electron Transfer: The Physics Behind the Biology

To understand how infrared light affects mitochondria, Seheult’s team turned to Marcus electron transfer theory, pioneered by Nobel laureate Rudolph Marcus in the 1960s.

Electrons don’t jump spontaneously between molecules. They require surrounding proteins, water, and lipids to twist into precise configurations—a process that demands energy called “reorganization energy.”

When infrared light hits these structures, it causes them to vibrate. This shifts the probability that molecules will be in the right arrangement for electron transfer to occur.

• If the crossing point is already accessible: Infrared light can push molecules away from optimal configurations, slowing electron transfer
• If the crossing point requires activation: Infrared light can push molecules toward optimal configurations, speeding electron transfer

This explains a puzzling finding from earlier studies: different infrared wavelengths can either increase or decrease mitochondrial activity.

Experiments Confirm the Mechanism

A 2018 study by Ma and colleagues tested this exact principle. Researchers built a custom molecule and used mid-infrared light to excite vibrational modes.

They found infrared light slowed forward electron transfer but accelerated backward transfer—precisely what Marcus theory predicts when nuclear orientations are shifted along energy curves.

IR excitation increases the probability of donor and acceptor energies to remain in degeneracy, resulting in IR-induced electron transfer rate enhancement.

Seheult notes he and co-author Dr. Robert Fosbury spoke with Marcus himself—just months before the scientist passed away at age 102—to discuss their hypothesis.

Deep-Sea Yeast Thrives on Infrared Light—Without Photosynthesis

Perhaps the most striking evidence comes from an unexpected source: yeast living near hydrothermal vents at the bottom of the ocean.

A 2026 study by Dai and colleagues isolated yeast from sediments near a “black smoker” chimney in the central Indian Ocean, more than half a meter from superheated mineral plumes reaching 378°C.

When researchers exposed these yeast cultures to near-infrared light (810–1050 nm) in temperature-controlled conditions, growth increased dramatically compared to dark controls—even though the yeast cannot photosynthesize.

Infrared light outperformed glucose. Adding glucose increased biomass by only 1.3-fold (not statistically significant), while 880-nanometer infrared light produced a threefold increase.

When researchers blocked cytochrome c oxidase (complex IV in mitochondria), near-infrared-stimulated growth dropped by 44%—suggesting the effect operates directly on mitochondrial machinery.

Cold Temperatures, Warm Light

Even more remarkable: infrared light allowed yeast to grow at cooler temperatures where dark controls remained dormant.

At 20°C, yeast exposed to 880-nanometer light grew vigorously while dark controls showed minimal activity. The effective activation energy dropped from 12 kilocalories per mole to just 2 kilocalories per mole.

Infrared light was making up for the cold temperatures by supplying vibrational activation rather than thermal activation.

Proteomics revealed the most upregulated protein after infrared exposure was a mitochondrial ribosomal protein (MRPs8), increased 6.7-fold.

Why Broadband Sunlight May Beat Monochromatic LEDs

Clinical studies using single-wavelength infrared devices have shown benefits—from reducing ICU length of stay to improving muscle strength in COVID-19 patients.

But Seheult’s hypothesis suggests broadband infrared from the sun may be even more effective.

“Sunlight contains a broad spectrum of wavelengths that can interact with many different vibrational modes and electron transfer steps,” he explains, “rather than targeting only one narrow pathway.”

Research from Jeffery’s lab supports this. When comparing monochromatic 850-nanometer light to a 60-watt incandescent bulb (which emits broad-spectrum infrared), the incandescent bulb produced greater improvements in color blindness.

• Monochromatic 850 nm: 9% improvement (head and body), 5% (body only)
• 60W incandescent bulb: 28% improvement, sustained for weeks

The research here aligns with the hypothesis, though direct mechanistic proof in human mitochondria remains to be demonstrated.

The Modern Indoor Environment: A Metabolic Desert?

LED bulbs emit virtually no infrared radiation. Low-emissivity (Low-E) glass windows, designed to improve energy efficiency, block infrared wavelengths.

Seheult measured infrared exposure in his own dining room with windows open: 0.8 watts per square meter.

Step outside under a shade tree with grass reflecting sunlight? 41.9 watts per square meter—more than 50 times higher.

We have set up a situation where outdoors we’re getting plenty of infrared light, versus being indoors where we have Low-E glass blocking it and LED bulbs producing none.

This raises profound questions about whether chronic infrared deficiency could contribute to the rising burden of metabolic diseases, especially among populations spending most of their time indoors.

Seasonal Mortality Patterns Point to Sunlight’s Role

Death rates from heart disease, cancer, stroke, Alzheimer’s, diabetes, and respiratory illness all peak one to three weeks after the shortest day of the year and bottom out after the longest day.

This pattern holds across both infectious and non-infectious causes. The seasonal variation in heart disease deaths alone exceeds total influenza deaths during flu season.

Australia shows the same pattern, but shifted six months—deaths peak in July, their winter. Singapore, 80 miles from the equator with year-round sun, shows no seasonal mortality pattern.

Multiple studies have linked mortality rates to latitude, independent of vitamin D levels, suggesting sunlight itself—particularly its infrared component—plays a direct metabolic role.

Hospitals Are Bringing Patients Outside

Armed with mounting evidence, hospitals worldwide are redesigning care spaces to maximize sunlight exposure.

A $1.5 billion hospital in Footscray, Australia, built ICU beds with direct outdoor access. King’s College Hospital in London invested £2 million to transform its rooftop into a critical care garden where up to six ICU patients can receive treatment surrounded by greenery and natural light.

St. George’s Hospital in London followed suit, creating a neurointensive care rooftop unit. Queen Camilla visited the facility in 2026 to recognize the innovation.

Randomized controlled trials using infrared vests delivering roughly 20–30 watts per square meter (comparable to sitting under a tree) showed 30% reductions in ICU length of stay and improved muscle strength in critically ill COVID-19 patients.

Metabolic Scaling Matches Solar Power Scaling

One of the paper’s most intriguing observations: metabolic rate scales with body mass to the 3/4 power across species from flies to elephants.

Solar power intercepted by an organism also scales to the 3/4 power of mass—nearly identical.

This doesn’t prove causation, but it suggests sunlight could be a universal regulator of metabolic activity across the biosphere, with mitochondria in all organisms tuned to respond to the same infrared wavelengths present in Earth’s solar photon field.

What Makes This Hypothesis Different

Earlier theories proposed infrared light works by activating a photoreceptor in cytochrome c oxidase (complex IV) or by reducing water viscosity around ATP synthase motors.

Seheult’s team doesn’t reject these mechanisms—but argues they’re incomplete.

The Marcus framework explains phenomena earlier models couldn’t: why some infrared wavelengths inhibit rather than enhance mitochondrial activity, why broadband light outperforms monochromatic sources, and why effects persist across vastly different organisms.

The paper is the first to integrate four separate literature streams:

• Mitochondrial electron transfer follows Marcus physics
• Red and near-infrared light alter mitochondrial function
• Water and protein structures affect electron transfer kinetics
• Infrared radiation changes molecular electron transfer rates

“The novelty lies in the mechanistic integration,” Seheult emphasizes, “not in any single component.”

What Comes Next

The hypothesis is testable. Future experiments could measure how different infrared wavelengths alter specific Marcus crossing configurations in isolated mitochondrial complexes, or track real-time changes in reorganization energy using advanced spectroscopy.

If validated, the implications extend far beyond biology. Urban planning, architecture, workplace design, and lighting standards may all need reconsideration.

Seheult introduces a new term: photometabolism—solar-driven, non-photosynthetic modulation of core metabolic processes.

It’s a concept that positions sunlight not as a passive environmental factor, but as an active participant in the biochemistry of life itself.

I believe that this hypothesis if true has major implications for the built environment and how we live and the type of light that we require to live, and I believe it’s one of the major reasons why we need to be treating our patients outside.

Sources

• Jeffery et al. (2025) – Longer wavelengths in sunlight penetrating human tissue
• Ma et al. (2018) – Infrared perturbation of charge separation and recombination
• Sanderson et al. (2018) – Inhibitory modulation of cytochrome c oxidase with near-infrared wavelengths
• Dai et al. (2026) – Infrared stimulation of mitochondrial metabolism in deep-sea yeast
• Hayashi et al. (2010) – Water-mediated electron transfer in iron-sulfur bridges
• Marcus and Sutin (1985) – Electron transfer reactions in chemistry

Seheult likens it to dollar bills falling from the sky. While visible light carries the most total energy (like $100 bills), infrared photons are the most numerous (like $1 bills).

The result? A unique atmospheric window that allows these photons to reach Earth’s surface in abundance—and potentially interact with living cells in ways artificial light cannot replicate.

Marcus Electron Transfer: The Physics Behind the Biology

To understand how infrared light affects mitochondria, Seheult’s team turned to Marcus electron transfer theory, pioneered by Nobel laureate Rudolph Marcus in the 1960s.

Electrons don’t jump spontaneously between molecules. They require surrounding proteins, water, and lipids to twist into precise configurations—a process that demands energy called “reorganization energy.”

When infrared light hits these structures, it causes them to vibrate. This shifts the probability that molecules will be in the right arrangement for electron transfer to occur.

• If the crossing point is already accessible: Infrared light can push molecules away from optimal configurations, slowing electron transfer
• If the crossing point requires activation: Infrared light can push molecules toward optimal configurations, speeding electron transfer

This explains a puzzling finding from earlier studies: different infrared wavelengths can either increase or decrease mitochondrial activity.

Experiments Confirm the Mechanism

A 2018 study by Ma and colleagues tested this exact principle. Researchers built a custom molecule and used mid-infrared light to excite vibrational modes.

They found infrared light slowed forward electron transfer but accelerated backward transfer—precisely what Marcus theory predicts when nuclear orientations are shifted along energy curves.

IR excitation increases the probability of donor and acceptor energies to remain in degeneracy, resulting in IR-induced electron transfer rate enhancement.

Seheult notes he and co-author Dr. Robert Fosbury spoke with Marcus himself—just months before the scientist passed away at age 102—to discuss their hypothesis.

Deep-Sea Yeast Thrives on Infrared Light—Without Photosynthesis

Perhaps the most striking evidence comes from an unexpected source: yeast living near hydrothermal vents at the bottom of the ocean.

A 2026 study by Dai and colleagues isolated yeast from sediments near a “black smoker” chimney in the central Indian Ocean, more than half a meter from superheated mineral plumes reaching 378°C.

When researchers exposed these yeast cultures to near-infrared light (810–1050 nm) in temperature-controlled conditions, growth increased dramatically compared to dark controls—even though the yeast cannot photosynthesize.

Infrared light outperformed glucose. Adding glucose increased biomass by only 1.3-fold (not statistically significant), while 880-nanometer infrared light produced a threefold increase.

When researchers blocked cytochrome c oxidase (complex IV in mitochondria), near-infrared-stimulated growth dropped by 44%—suggesting the effect operates directly on mitochondrial machinery.

Cold Temperatures, Warm Light

Even more remarkable: infrared light allowed yeast to grow at cooler temperatures where dark controls remained dormant.

At 20°C, yeast exposed to 880-nanometer light grew vigorously while dark controls showed minimal activity. The effective activation energy dropped from 12 kilocalories per mole to just 2 kilocalories per mole.

Infrared light was making up for the cold temperatures by supplying vibrational activation rather than thermal activation.

Proteomics revealed the most upregulated protein after infrared exposure was a mitochondrial ribosomal protein (MRPs8), increased 6.7-fold.

Why Broadband Sunlight May Beat Monochromatic LEDs

Clinical studies using single-wavelength infrared devices have shown benefits—from reducing ICU length of stay to improving muscle strength in COVID-19 patients.

But Seheult’s hypothesis suggests broadband infrared from the sun may be even more effective.

“Sunlight contains a broad spectrum of wavelengths that can interact with many different vibrational modes and electron transfer steps,” he explains, “rather than targeting only one narrow pathway.”

Research from Jeffery’s lab supports this. When comparing monochromatic 850-nanometer light to a 60-watt incandescent bulb (which emits broad-spectrum infrared), the incandescent bulb produced greater improvements in color blindness.

• Monochromatic 850 nm: 9% improvement (head and body), 5% (body only)
• 60W incandescent bulb: 28% improvement, sustained for weeks

The research here aligns with the hypothesis, though direct mechanistic proof in human mitochondria remains to be demonstrated.

The Modern Indoor Environment: A Metabolic Desert?

LED bulbs emit virtually no infrared radiation. Low-emissivity (Low-E) glass windows, designed to improve energy efficiency, block infrared wavelengths.

Seheult measured infrared exposure in his own dining room with windows open: 0.8 watts per square meter.

Step outside under a shade tree with grass reflecting sunlight? 41.9 watts per square meter—more than 50 times higher.

We have set up a situation where outdoors we’re getting plenty of infrared light, versus being indoors where we have Low-E glass blocking it and LED bulbs producing none.

This raises profound questions about whether chronic infrared deficiency could contribute to the rising burden of metabolic diseases, especially among populations spending most of their time indoors.

Seasonal Mortality Patterns Point to Sunlight’s Role

Death rates from heart disease, cancer, stroke, Alzheimer’s, diabetes, and respiratory illness all peak one to three weeks after the shortest day of the year and bottom out after the longest day.

This pattern holds across both infectious and non-infectious causes. The seasonal variation in heart disease deaths alone exceeds total influenza deaths during flu season.

Australia shows the same pattern, but shifted six months—deaths peak in July, their winter. Singapore, 80 miles from the equator with year-round sun, shows no seasonal mortality pattern.

Multiple studies have linked mortality rates to latitude, independent of vitamin D levels, suggesting sunlight itself—particularly its infrared component—plays a direct metabolic role.

Hospitals Are Bringing Patients Outside

Armed with mounting evidence, hospitals worldwide are redesigning care spaces to maximize sunlight exposure.

A $1.5 billion hospital in Footscray, Australia, built ICU beds with direct outdoor access. King’s College Hospital in London invested £2 million to transform its rooftop into a critical care garden where up to six ICU patients can receive treatment surrounded by greenery and natural light.

St. George’s Hospital in London followed suit, creating a neurointensive care rooftop unit. Queen Camilla visited the facility in 2026 to recognize the innovation.

Randomized controlled trials using infrared vests delivering roughly 20–30 watts per square meter (comparable to sitting under a tree) showed 30% reductions in ICU length of stay and improved muscle strength in critically ill COVID-19 patients.

Metabolic Scaling Matches Solar Power Scaling

One of the paper’s most intriguing observations: metabolic rate scales with body mass to the 3/4 power across species from flies to elephants.

Solar power intercepted by an organism also scales to the 3/4 power of mass—nearly identical.

This doesn’t prove causation, but it suggests sunlight could be a universal regulator of metabolic activity across the biosphere, with mitochondria in all organisms tuned to respond to the same infrared wavelengths present in Earth’s solar photon field.

What Makes This Hypothesis Different

Earlier theories proposed infrared light works by activating a photoreceptor in cytochrome c oxidase (complex IV) or by reducing water viscosity around ATP synthase motors.

Seheult’s team doesn’t reject these mechanisms—but argues they’re incomplete.

The Marcus framework explains phenomena earlier models couldn’t: why some infrared wavelengths inhibit rather than enhance mitochondrial activity, why broadband light outperforms monochromatic sources, and why effects persist across vastly different organisms.

The paper is the first to integrate four separate literature streams:

• Mitochondrial electron transfer follows Marcus physics
• Red and near-infrared light alter mitochondrial function
• Water and protein structures affect electron transfer kinetics
• Infrared radiation changes molecular electron transfer rates

“The novelty lies in the mechanistic integration,” Seheult emphasizes, “not in any single component.”

What Comes Next

The hypothesis is testable. Future experiments could measure how different infrared wavelengths alter specific Marcus crossing configurations in isolated mitochondrial complexes, or track real-time changes in reorganization energy using advanced spectroscopy.

If validated, the implications extend far beyond biology. Urban planning, architecture, workplace design, and lighting standards may all need reconsideration.

Seheult introduces a new term: photometabolism—solar-driven, non-photosynthetic modulation of core metabolic processes.

It’s a concept that positions sunlight not as a passive environmental factor, but as an active participant in the biochemistry of life itself.

I believe that this hypothesis if true has major implications for the built environment and how we live and the type of light that we require to live, and I believe it’s one of the major reasons why we need to be treating our patients outside.

Sources

• Jeffery et al. (2025) – Longer wavelengths in sunlight penetrating human tissue
• Ma et al. (2018) – Infrared perturbation of charge separation and recombination
• Sanderson et al. (2018) – Inhibitory modulation of cytochrome c oxidase with near-infrared wavelengths
• Dai et al. (2026) – Infrared stimulation of mitochondrial metabolism in deep-sea yeast
• Hayashi et al. (2010) – Water-mediated electron transfer in iron-sulfur bridges
• Marcus and Sutin (1985) – Electron transfer reactions in chemistry

Seheult likens it to dollar bills falling from the sky. While visible light carries the most total energy (like $100 bills), infrared photons are the most numerous (like $1 bills).

The result? A unique atmospheric window that allows these photons to reach Earth’s surface in abundance—and potentially interact with living cells in ways artificial light cannot replicate.

Marcus Electron Transfer: The Physics Behind the Biology

To understand how infrared light affects mitochondria, Seheult’s team turned to Marcus electron transfer theory, pioneered by Nobel laureate Rudolph Marcus in the 1960s.

Electrons don’t jump spontaneously between molecules. They require surrounding proteins, water, and lipids to twist into precise configurations—a process that demands energy called “reorganization energy.”

When infrared light hits these structures, it causes them to vibrate. This shifts the probability that molecules will be in the right arrangement for electron transfer to occur.

• If the crossing point is already accessible: Infrared light can push molecules away from optimal configurations, slowing electron transfer
• If the crossing point requires activation: Infrared light can push molecules toward optimal configurations, speeding electron transfer

This explains a puzzling finding from earlier studies: different infrared wavelengths can either increase or decrease mitochondrial activity.

Experiments Confirm the Mechanism

A 2018 study by Ma and colleagues tested this exact principle. Researchers built a custom molecule and used mid-infrared light to excite vibrational modes.

They found infrared light slowed forward electron transfer but accelerated backward transfer—precisely what Marcus theory predicts when nuclear orientations are shifted along energy curves.

IR excitation increases the probability of donor and acceptor energies to remain in degeneracy, resulting in IR-induced electron transfer rate enhancement.

Seheult notes he and co-author Dr. Robert Fosbury spoke with Marcus himself—just months before the scientist passed away at age 102—to discuss their hypothesis.

Deep-Sea Yeast Thrives on Infrared Light—Without Photosynthesis

Perhaps the most striking evidence comes from an unexpected source: yeast living near hydrothermal vents at the bottom of the ocean.

A 2026 study by Dai and colleagues isolated yeast from sediments near a “black smoker” chimney in the central Indian Ocean, more than half a meter from superheated mineral plumes reaching 378°C.

When researchers exposed these yeast cultures to near-infrared light (810–1050 nm) in temperature-controlled conditions, growth increased dramatically compared to dark controls—even though the yeast cannot photosynthesize.

Infrared light outperformed glucose. Adding glucose increased biomass by only 1.3-fold (not statistically significant), while 880-nanometer infrared light produced a threefold increase.

When researchers blocked cytochrome c oxidase (complex IV in mitochondria), near-infrared-stimulated growth dropped by 44%—suggesting the effect operates directly on mitochondrial machinery.

Cold Temperatures, Warm Light

Even more remarkable: infrared light allowed yeast to grow at cooler temperatures where dark controls remained dormant.

At 20°C, yeast exposed to 880-nanometer light grew vigorously while dark controls showed minimal activity. The effective activation energy dropped from 12 kilocalories per mole to just 2 kilocalories per mole.

Infrared light was making up for the cold temperatures by supplying vibrational activation rather than thermal activation.

Proteomics revealed the most upregulated protein after infrared exposure was a mitochondrial ribosomal protein (MRPs8), increased 6.7-fold.

Why Broadband Sunlight May Beat Monochromatic LEDs

Clinical studies using single-wavelength infrared devices have shown benefits—from reducing ICU length of stay to improving muscle strength in COVID-19 patients.

But Seheult’s hypothesis suggests broadband infrared from the sun may be even more effective.

“Sunlight contains a broad spectrum of wavelengths that can interact with many different vibrational modes and electron transfer steps,” he explains, “rather than targeting only one narrow pathway.”

Research from Jeffery’s lab supports this. When comparing monochromatic 850-nanometer light to a 60-watt incandescent bulb (which emits broad-spectrum infrared), the incandescent bulb produced greater improvements in color blindness.

• Monochromatic 850 nm: 9% improvement (head and body), 5% (body only)
• 60W incandescent bulb: 28% improvement, sustained for weeks

The research here aligns with the hypothesis, though direct mechanistic proof in human mitochondria remains to be demonstrated.

The Modern Indoor Environment: A Metabolic Desert?

LED bulbs emit virtually no infrared radiation. Low-emissivity (Low-E) glass windows, designed to improve energy efficiency, block infrared wavelengths.

Seheult measured infrared exposure in his own dining room with windows open: 0.8 watts per square meter.

Step outside under a shade tree with grass reflecting sunlight? 41.9 watts per square meter—more than 50 times higher.

We have set up a situation where outdoors we’re getting plenty of infrared light, versus being indoors where we have Low-E glass blocking it and LED bulbs producing none.

This raises profound questions about whether chronic infrared deficiency could contribute to the rising burden of metabolic diseases, especially among populations spending most of their time indoors.

Seasonal Mortality Patterns Point to Sunlight’s Role

Death rates from heart disease, cancer, stroke, Alzheimer’s, diabetes, and respiratory illness all peak one to three weeks after the shortest day of the year and bottom out after the longest day.

This pattern holds across both infectious and non-infectious causes. The seasonal variation in heart disease deaths alone exceeds total influenza deaths during flu season.

Australia shows the same pattern, but shifted six months—deaths peak in July, their winter. Singapore, 80 miles from the equator with year-round sun, shows no seasonal mortality pattern.

Multiple studies have linked mortality rates to latitude, independent of vitamin D levels, suggesting sunlight itself—particularly its infrared component—plays a direct metabolic role.

Hospitals Are Bringing Patients Outside

Armed with mounting evidence, hospitals worldwide are redesigning care spaces to maximize sunlight exposure.

A $1.5 billion hospital in Footscray, Australia, built ICU beds with direct outdoor access. King’s College Hospital in London invested £2 million to transform its rooftop into a critical care garden where up to six ICU patients can receive treatment surrounded by greenery and natural light.

St. George’s Hospital in London followed suit, creating a neurointensive care rooftop unit. Queen Camilla visited the facility in 2026 to recognize the innovation.

Randomized controlled trials using infrared vests delivering roughly 20–30 watts per square meter (comparable to sitting under a tree) showed 30% reductions in ICU length of stay and improved muscle strength in critically ill COVID-19 patients.

Metabolic Scaling Matches Solar Power Scaling

One of the paper’s most intriguing observations: metabolic rate scales with body mass to the 3/4 power across species from flies to elephants.

Solar power intercepted by an organism also scales to the 3/4 power of mass—nearly identical.

This doesn’t prove causation, but it suggests sunlight could be a universal regulator of metabolic activity across the biosphere, with mitochondria in all organisms tuned to respond to the same infrared wavelengths present in Earth’s solar photon field.

What Makes This Hypothesis Different

Earlier theories proposed infrared light works by activating a photoreceptor in cytochrome c oxidase (complex IV) or by reducing water viscosity around ATP synthase motors.

Seheult’s team doesn’t reject these mechanisms—but argues they’re incomplete.

The Marcus framework explains phenomena earlier models couldn’t: why some infrared wavelengths inhibit rather than enhance mitochondrial activity, why broadband light outperforms monochromatic sources, and why effects persist across vastly different organisms.

The paper is the first to integrate four separate literature streams:

• Mitochondrial electron transfer follows Marcus physics
• Red and near-infrared light alter mitochondrial function
• Water and protein structures affect electron transfer kinetics
• Infrared radiation changes molecular electron transfer rates

“The novelty lies in the mechanistic integration,” Seheult emphasizes, “not in any single component.”

What Comes Next

The hypothesis is testable. Future experiments could measure how different infrared wavelengths alter specific Marcus crossing configurations in isolated mitochondrial complexes, or track real-time changes in reorganization energy using advanced spectroscopy.

If validated, the implications extend far beyond biology. Urban planning, architecture, workplace design, and lighting standards may all need reconsideration.

Seheult introduces a new term: photometabolism—solar-driven, non-photosynthetic modulation of core metabolic processes.

It’s a concept that positions sunlight not as a passive environmental factor, but as an active participant in the biochemistry of life itself.

I believe that this hypothesis if true has major implications for the built environment and how we live and the type of light that we require to live, and I believe it’s one of the major reasons why we need to be treating our patients outside.

Sources

• Jeffery et al. (2025) – Longer wavelengths in sunlight penetrating human tissue
• Ma et al. (2018) – Infrared perturbation of charge separation and recombination
• Sanderson et al. (2018) – Inhibitory modulation of cytochrome c oxidase with near-infrared wavelengths
• Dai et al. (2026) – Infrared stimulation of mitochondrial metabolism in deep-sea yeast
• Hayashi et al. (2010) – Water-mediated electron transfer in iron-sulfur bridges
• Marcus and Sutin (1985) – Electron transfer reactions in chemistry

This peak occurs because of the sun’s photosphere, a layer rich in negatively charged hydrogen atoms called hydride ions. These ions absorb higher-energy photons and re-emit them at exactly 0.754 electron volts.

Seheult likens it to dollar bills falling from the sky. While visible light carries the most total energy (like $100 bills), infrared photons are the most numerous (like $1 bills).

The result? A unique atmospheric window that allows these photons to reach Earth’s surface in abundance—and potentially interact with living cells in ways artificial light cannot replicate.

Marcus Electron Transfer: The Physics Behind the Biology

To understand how infrared light affects mitochondria, Seheult’s team turned to Marcus electron transfer theory, pioneered by Nobel laureate Rudolph Marcus in the 1960s.

Electrons don’t jump spontaneously between molecules. They require surrounding proteins, water, and lipids to twist into precise configurations—a process that demands energy called “reorganization energy.”

When infrared light hits these structures, it causes them to vibrate. This shifts the probability that molecules will be in the right arrangement for electron transfer to occur.

• If the crossing point is already accessible: Infrared light can push molecules away from optimal configurations, slowing electron transfer
• If the crossing point requires activation: Infrared light can push molecules toward optimal configurations, speeding electron transfer

This explains a puzzling finding from earlier studies: different infrared wavelengths can either increase or decrease mitochondrial activity.

Experiments Confirm the Mechanism

A 2018 study by Ma and colleagues tested this exact principle. Researchers built a custom molecule and used mid-infrared light to excite vibrational modes.

They found infrared light slowed forward electron transfer but accelerated backward transfer—precisely what Marcus theory predicts when nuclear orientations are shifted along energy curves.

IR excitation increases the probability of donor and acceptor energies to remain in degeneracy, resulting in IR-induced electron transfer rate enhancement.

Seheult notes he and co-author Dr. Robert Fosbury spoke with Marcus himself—just months before the scientist passed away at age 102—to discuss their hypothesis.

Deep-Sea Yeast Thrives on Infrared Light—Without Photosynthesis

Perhaps the most striking evidence comes from an unexpected source: yeast living near hydrothermal vents at the bottom of the ocean.

A 2026 study by Dai and colleagues isolated yeast from sediments near a “black smoker” chimney in the central Indian Ocean, more than half a meter from superheated mineral plumes reaching 378°C.

When researchers exposed these yeast cultures to near-infrared light (810–1050 nm) in temperature-controlled conditions, growth increased dramatically compared to dark controls—even though the yeast cannot photosynthesize.

Infrared light outperformed glucose. Adding glucose increased biomass by only 1.3-fold (not statistically significant), while 880-nanometer infrared light produced a threefold increase.

When researchers blocked cytochrome c oxidase (complex IV in mitochondria), near-infrared-stimulated growth dropped by 44%—suggesting the effect operates directly on mitochondrial machinery.

Cold Temperatures, Warm Light

Even more remarkable: infrared light allowed yeast to grow at cooler temperatures where dark controls remained dormant.

At 20°C, yeast exposed to 880-nanometer light grew vigorously while dark controls showed minimal activity. The effective activation energy dropped from 12 kilocalories per mole to just 2 kilocalories per mole.

Infrared light was making up for the cold temperatures by supplying vibrational activation rather than thermal activation.

Proteomics revealed the most upregulated protein after infrared exposure was a mitochondrial ribosomal protein (MRPs8), increased 6.7-fold.

Why Broadband Sunlight May Beat Monochromatic LEDs

Clinical studies using single-wavelength infrared devices have shown benefits—from reducing ICU length of stay to improving muscle strength in COVID-19 patients.

But Seheult’s hypothesis suggests broadband infrared from the sun may be even more effective.

“Sunlight contains a broad spectrum of wavelengths that can interact with many different vibrational modes and electron transfer steps,” he explains, “rather than targeting only one narrow pathway.”

Research from Jeffery’s lab supports this. When comparing monochromatic 850-nanometer light to a 60-watt incandescent bulb (which emits broad-spectrum infrared), the incandescent bulb produced greater improvements in color blindness.

• Monochromatic 850 nm: 9% improvement (head and body), 5% (body only)
• 60W incandescent bulb: 28% improvement, sustained for weeks

The research here aligns with the hypothesis, though direct mechanistic proof in human mitochondria remains to be demonstrated.

The Modern Indoor Environment: A Metabolic Desert?

LED bulbs emit virtually no infrared radiation. Low-emissivity (Low-E) glass windows, designed to improve energy efficiency, block infrared wavelengths.

Seheult measured infrared exposure in his own dining room with windows open: 0.8 watts per square meter.

Step outside under a shade tree with grass reflecting sunlight? 41.9 watts per square meter—more than 50 times higher.

We have set up a situation where outdoors we’re getting plenty of infrared light, versus being indoors where we have Low-E glass blocking it and LED bulbs producing none.

This raises profound questions about whether chronic infrared deficiency could contribute to the rising burden of metabolic diseases, especially among populations spending most of their time indoors.

Seasonal Mortality Patterns Point to Sunlight’s Role

Death rates from heart disease, cancer, stroke, Alzheimer’s, diabetes, and respiratory illness all peak one to three weeks after the shortest day of the year and bottom out after the longest day.

This pattern holds across both infectious and non-infectious causes. The seasonal variation in heart disease deaths alone exceeds total influenza deaths during flu season.

Australia shows the same pattern, but shifted six months—deaths peak in July, their winter. Singapore, 80 miles from the equator with year-round sun, shows no seasonal mortality pattern.

Multiple studies have linked mortality rates to latitude, independent of vitamin D levels, suggesting sunlight itself—particularly its infrared component—plays a direct metabolic role.

Hospitals Are Bringing Patients Outside

Armed with mounting evidence, hospitals worldwide are redesigning care spaces to maximize sunlight exposure.

A $1.5 billion hospital in Footscray, Australia, built ICU beds with direct outdoor access. King’s College Hospital in London invested £2 million to transform its rooftop into a critical care garden where up to six ICU patients can receive treatment surrounded by greenery and natural light.

St. George’s Hospital in London followed suit, creating a neurointensive care rooftop unit. Queen Camilla visited the facility in 2026 to recognize the innovation.

Randomized controlled trials using infrared vests delivering roughly 20–30 watts per square meter (comparable to sitting under a tree) showed 30% reductions in ICU length of stay and improved muscle strength in critically ill COVID-19 patients.

Metabolic Scaling Matches Solar Power Scaling

One of the paper’s most intriguing observations: metabolic rate scales with body mass to the 3/4 power across species from flies to elephants.

Solar power intercepted by an organism also scales to the 3/4 power of mass—nearly identical.

This doesn’t prove causation, but it suggests sunlight could be a universal regulator of metabolic activity across the biosphere, with mitochondria in all organisms tuned to respond to the same infrared wavelengths present in Earth’s solar photon field.

What Makes This Hypothesis Different

Earlier theories proposed infrared light works by activating a photoreceptor in cytochrome c oxidase (complex IV) or by reducing water viscosity around ATP synthase motors.

Seheult’s team doesn’t reject these mechanisms—but argues they’re incomplete.

The Marcus framework explains phenomena earlier models couldn’t: why some infrared wavelengths inhibit rather than enhance mitochondrial activity, why broadband light outperforms monochromatic sources, and why effects persist across vastly different organisms.

The paper is the first to integrate four separate literature streams:

• Mitochondrial electron transfer follows Marcus physics
• Red and near-infrared light alter mitochondrial function
• Water and protein structures affect electron transfer kinetics
• Infrared radiation changes molecular electron transfer rates

“The novelty lies in the mechanistic integration,” Seheult emphasizes, “not in any single component.”

What Comes Next

The hypothesis is testable. Future experiments could measure how different infrared wavelengths alter specific Marcus crossing configurations in isolated mitochondrial complexes, or track real-time changes in reorganization energy using advanced spectroscopy.

If validated, the implications extend far beyond biology. Urban planning, architecture, workplace design, and lighting standards may all need reconsideration.

Seheult introduces a new term: photometabolism—solar-driven, non-photosynthetic modulation of core metabolic processes.

It’s a concept that positions sunlight not as a passive environmental factor, but as an active participant in the biochemistry of life itself.

I believe that this hypothesis if true has major implications for the built environment and how we live and the type of light that we require to live, and I believe it’s one of the major reasons why we need to be treating our patients outside.

Sources

• Jeffery et al. (2025) – Longer wavelengths in sunlight penetrating human tissue
• Ma et al. (2018) – Infrared perturbation of charge separation and recombination
• Sanderson et al. (2018) – Inhibitory modulation of cytochrome c oxidase with near-infrared wavelengths
• Dai et al. (2026) – Infrared stimulation of mitochondrial metabolism in deep-sea yeast
• Hayashi et al. (2010) – Water-mediated electron transfer in iron-sulfur bridges
• Marcus and Sutin (1985) – Electron transfer reactions in chemistry

This peak occurs because of the sun’s photosphere, a layer rich in negatively charged hydrogen atoms called hydride ions. These ions absorb higher-energy photons and re-emit them at exactly 0.754 electron volts.

Seheult likens it to dollar bills falling from the sky. While visible light carries the most total energy (like $100 bills), infrared photons are the most numerous (like $1 bills).

The result? A unique atmospheric window that allows these photons to reach Earth’s surface in abundance—and potentially interact with living cells in ways artificial light cannot replicate.

Marcus Electron Transfer: The Physics Behind the Biology

To understand how infrared light affects mitochondria, Seheult’s team turned to Marcus electron transfer theory, pioneered by Nobel laureate Rudolph Marcus in the 1960s.

Electrons don’t jump spontaneously between molecules. They require surrounding proteins, water, and lipids to twist into precise configurations—a process that demands energy called “reorganization energy.”

When infrared light hits these structures, it causes them to vibrate. This shifts the probability that molecules will be in the right arrangement for electron transfer to occur.

• If the crossing point is already accessible: Infrared light can push molecules away from optimal configurations, slowing electron transfer
• If the crossing point requires activation: Infrared light can push molecules toward optimal configurations, speeding electron transfer

This explains a puzzling finding from earlier studies: different infrared wavelengths can either increase or decrease mitochondrial activity.

Experiments Confirm the Mechanism

A 2018 study by Ma and colleagues tested this exact principle. Researchers built a custom molecule and used mid-infrared light to excite vibrational modes.

They found infrared light slowed forward electron transfer but accelerated backward transfer—precisely what Marcus theory predicts when nuclear orientations are shifted along energy curves.

IR excitation increases the probability of donor and acceptor energies to remain in degeneracy, resulting in IR-induced electron transfer rate enhancement.

Seheult notes he and co-author Dr. Robert Fosbury spoke with Marcus himself—just months before the scientist passed away at age 102—to discuss their hypothesis.

Deep-Sea Yeast Thrives on Infrared Light—Without Photosynthesis

Perhaps the most striking evidence comes from an unexpected source: yeast living near hydrothermal vents at the bottom of the ocean.

A 2026 study by Dai and colleagues isolated yeast from sediments near a “black smoker” chimney in the central Indian Ocean, more than half a meter from superheated mineral plumes reaching 378°C.

When researchers exposed these yeast cultures to near-infrared light (810–1050 nm) in temperature-controlled conditions, growth increased dramatically compared to dark controls—even though the yeast cannot photosynthesize.

Infrared light outperformed glucose. Adding glucose increased biomass by only 1.3-fold (not statistically significant), while 880-nanometer infrared light produced a threefold increase.

When researchers blocked cytochrome c oxidase (complex IV in mitochondria), near-infrared-stimulated growth dropped by 44%—suggesting the effect operates directly on mitochondrial machinery.

Cold Temperatures, Warm Light

Even more remarkable: infrared light allowed yeast to grow at cooler temperatures where dark controls remained dormant.

At 20°C, yeast exposed to 880-nanometer light grew vigorously while dark controls showed minimal activity. The effective activation energy dropped from 12 kilocalories per mole to just 2 kilocalories per mole.

Infrared light was making up for the cold temperatures by supplying vibrational activation rather than thermal activation.

Proteomics revealed the most upregulated protein after infrared exposure was a mitochondrial ribosomal protein (MRPs8), increased 6.7-fold.

Why Broadband Sunlight May Beat Monochromatic LEDs

Clinical studies using single-wavelength infrared devices have shown benefits—from reducing ICU length of stay to improving muscle strength in COVID-19 patients.

But Seheult’s hypothesis suggests broadband infrared from the sun may be even more effective.

“Sunlight contains a broad spectrum of wavelengths that can interact with many different vibrational modes and electron transfer steps,” he explains, “rather than targeting only one narrow pathway.”

Research from Jeffery’s lab supports this. When comparing monochromatic 850-nanometer light to a 60-watt incandescent bulb (which emits broad-spectrum infrared), the incandescent bulb produced greater improvements in color blindness.

• Monochromatic 850 nm: 9% improvement (head and body), 5% (body only)
• 60W incandescent bulb: 28% improvement, sustained for weeks

The research here aligns with the hypothesis, though direct mechanistic proof in human mitochondria remains to be demonstrated.

The Modern Indoor Environment: A Metabolic Desert?

LED bulbs emit virtually no infrared radiation. Low-emissivity (Low-E) glass windows, designed to improve energy efficiency, block infrared wavelengths.

Seheult measured infrared exposure in his own dining room with windows open: 0.8 watts per square meter.

Step outside under a shade tree with grass reflecting sunlight? 41.9 watts per square meter—more than 50 times higher.

We have set up a situation where outdoors we’re getting plenty of infrared light, versus being indoors where we have Low-E glass blocking it and LED bulbs producing none.

This raises profound questions about whether chronic infrared deficiency could contribute to the rising burden of metabolic diseases, especially among populations spending most of their time indoors.

Seasonal Mortality Patterns Point to Sunlight’s Role

Death rates from heart disease, cancer, stroke, Alzheimer’s, diabetes, and respiratory illness all peak one to three weeks after the shortest day of the year and bottom out after the longest day.

This pattern holds across both infectious and non-infectious causes. The seasonal variation in heart disease deaths alone exceeds total influenza deaths during flu season.

Australia shows the same pattern, but shifted six months—deaths peak in July, their winter. Singapore, 80 miles from the equator with year-round sun, shows no seasonal mortality pattern.

Multiple studies have linked mortality rates to latitude, independent of vitamin D levels, suggesting sunlight itself—particularly its infrared component—plays a direct metabolic role.

Hospitals Are Bringing Patients Outside

Armed with mounting evidence, hospitals worldwide are redesigning care spaces to maximize sunlight exposure.

A $1.5 billion hospital in Footscray, Australia, built ICU beds with direct outdoor access. King’s College Hospital in London invested £2 million to transform its rooftop into a critical care garden where up to six ICU patients can receive treatment surrounded by greenery and natural light.

St. George’s Hospital in London followed suit, creating a neurointensive care rooftop unit. Queen Camilla visited the facility in 2026 to recognize the innovation.

Randomized controlled trials using infrared vests delivering roughly 20–30 watts per square meter (comparable to sitting under a tree) showed 30% reductions in ICU length of stay and improved muscle strength in critically ill COVID-19 patients.

Metabolic Scaling Matches Solar Power Scaling

One of the paper’s most intriguing observations: metabolic rate scales with body mass to the 3/4 power across species from flies to elephants.

Solar power intercepted by an organism also scales to the 3/4 power of mass—nearly identical.

This doesn’t prove causation, but it suggests sunlight could be a universal regulator of metabolic activity across the biosphere, with mitochondria in all organisms tuned to respond to the same infrared wavelengths present in Earth’s solar photon field.

What Makes This Hypothesis Different

Earlier theories proposed infrared light works by activating a photoreceptor in cytochrome c oxidase (complex IV) or by reducing water viscosity around ATP synthase motors.

Seheult’s team doesn’t reject these mechanisms—but argues they’re incomplete.

The Marcus framework explains phenomena earlier models couldn’t: why some infrared wavelengths inhibit rather than enhance mitochondrial activity, why broadband light outperforms monochromatic sources, and why effects persist across vastly different organisms.

The paper is the first to integrate four separate literature streams:

• Mitochondrial electron transfer follows Marcus physics
• Red and near-infrared light alter mitochondrial function
• Water and protein structures affect electron transfer kinetics
• Infrared radiation changes molecular electron transfer rates

“The novelty lies in the mechanistic integration,” Seheult emphasizes, “not in any single component.”

What Comes Next

The hypothesis is testable. Future experiments could measure how different infrared wavelengths alter specific Marcus crossing configurations in isolated mitochondrial complexes, or track real-time changes in reorganization energy using advanced spectroscopy.

If validated, the implications extend far beyond biology. Urban planning, architecture, workplace design, and lighting standards may all need reconsideration.

Seheult introduces a new term: photometabolism—solar-driven, non-photosynthetic modulation of core metabolic processes.

It’s a concept that positions sunlight not as a passive environmental factor, but as an active participant in the biochemistry of life itself.

I believe that this hypothesis if true has major implications for the built environment and how we live and the type of light that we require to live, and I believe it’s one of the major reasons why we need to be treating our patients outside.

Sources

• Jeffery et al. (2025) – Longer wavelengths in sunlight penetrating human tissue
• Ma et al. (2018) – Infrared perturbation of charge separation and recombination
• Sanderson et al. (2018) – Inhibitory modulation of cytochrome c oxidase with near-infrared wavelengths
• Dai et al. (2026) – Infrared stimulation of mitochondrial metabolism in deep-sea yeast
• Hayashi et al. (2010) – Water-mediated electron transfer in iron-sulfur bridges
• Marcus and Sutin (1985) – Electron transfer reactions in chemistry

Not all light sources are created equal. The sun emits a broad spectrum of infrared wavelengths, but one particular photon energy—0.754 electron volts—is especially abundant.

This peak occurs because of the sun’s photosphere, a layer rich in negatively charged hydrogen atoms called hydride ions. These ions absorb higher-energy photons and re-emit them at exactly 0.754 electron volts.

Seheult likens it to dollar bills falling from the sky. While visible light carries the most total energy (like $100 bills), infrared photons are the most numerous (like $1 bills).

The result? A unique atmospheric window that allows these photons to reach Earth’s surface in abundance—and potentially interact with living cells in ways artificial light cannot replicate.

Marcus Electron Transfer: The Physics Behind the Biology

To understand how infrared light affects mitochondria, Seheult’s team turned to Marcus electron transfer theory, pioneered by Nobel laureate Rudolph Marcus in the 1960s.

Electrons don’t jump spontaneously between molecules. They require surrounding proteins, water, and lipids to twist into precise configurations—a process that demands energy called “reorganization energy.”

When infrared light hits these structures, it causes them to vibrate. This shifts the probability that molecules will be in the right arrangement for electron transfer to occur.

• If the crossing point is already accessible: Infrared light can push molecules away from optimal configurations, slowing electron transfer
• If the crossing point requires activation: Infrared light can push molecules toward optimal configurations, speeding electron transfer

This explains a puzzling finding from earlier studies: different infrared wavelengths can either increase or decrease mitochondrial activity.

Experiments Confirm the Mechanism

A 2018 study by Ma and colleagues tested this exact principle. Researchers built a custom molecule and used mid-infrared light to excite vibrational modes.

They found infrared light slowed forward electron transfer but accelerated backward transfer—precisely what Marcus theory predicts when nuclear orientations are shifted along energy curves.

IR excitation increases the probability of donor and acceptor energies to remain in degeneracy, resulting in IR-induced electron transfer rate enhancement.

Seheult notes he and co-author Dr. Robert Fosbury spoke with Marcus himself—just months before the scientist passed away at age 102—to discuss their hypothesis.

Deep-Sea Yeast Thrives on Infrared Light—Without Photosynthesis

Perhaps the most striking evidence comes from an unexpected source: yeast living near hydrothermal vents at the bottom of the ocean.

A 2026 study by Dai and colleagues isolated yeast from sediments near a “black smoker” chimney in the central Indian Ocean, more than half a meter from superheated mineral plumes reaching 378°C.

When researchers exposed these yeast cultures to near-infrared light (810–1050 nm) in temperature-controlled conditions, growth increased dramatically compared to dark controls—even though the yeast cannot photosynthesize.

Infrared light outperformed glucose. Adding glucose increased biomass by only 1.3-fold (not statistically significant), while 880-nanometer infrared light produced a threefold increase.

When researchers blocked cytochrome c oxidase (complex IV in mitochondria), near-infrared-stimulated growth dropped by 44%—suggesting the effect operates directly on mitochondrial machinery.

Cold Temperatures, Warm Light

Even more remarkable: infrared light allowed yeast to grow at cooler temperatures where dark controls remained dormant.

At 20°C, yeast exposed to 880-nanometer light grew vigorously while dark controls showed minimal activity. The effective activation energy dropped from 12 kilocalories per mole to just 2 kilocalories per mole.

Infrared light was making up for the cold temperatures by supplying vibrational activation rather than thermal activation.

Proteomics revealed the most upregulated protein after infrared exposure was a mitochondrial ribosomal protein (MRPs8), increased 6.7-fold.

Why Broadband Sunlight May Beat Monochromatic LEDs

Clinical studies using single-wavelength infrared devices have shown benefits—from reducing ICU length of stay to improving muscle strength in COVID-19 patients.

But Seheult’s hypothesis suggests broadband infrared from the sun may be even more effective.

“Sunlight contains a broad spectrum of wavelengths that can interact with many different vibrational modes and electron transfer steps,” he explains, “rather than targeting only one narrow pathway.”

Research from Jeffery’s lab supports this. When comparing monochromatic 850-nanometer light to a 60-watt incandescent bulb (which emits broad-spectrum infrared), the incandescent bulb produced greater improvements in color blindness.

• Monochromatic 850 nm: 9% improvement (head and body), 5% (body only)
• 60W incandescent bulb: 28% improvement, sustained for weeks

The research here aligns with the hypothesis, though direct mechanistic proof in human mitochondria remains to be demonstrated.

The Modern Indoor Environment: A Metabolic Desert?

LED bulbs emit virtually no infrared radiation. Low-emissivity (Low-E) glass windows, designed to improve energy efficiency, block infrared wavelengths.

Seheult measured infrared exposure in his own dining room with windows open: 0.8 watts per square meter.

Step outside under a shade tree with grass reflecting sunlight? 41.9 watts per square meter—more than 50 times higher.

We have set up a situation where outdoors we’re getting plenty of infrared light, versus being indoors where we have Low-E glass blocking it and LED bulbs producing none.

This raises profound questions about whether chronic infrared deficiency could contribute to the rising burden of metabolic diseases, especially among populations spending most of their time indoors.

Seasonal Mortality Patterns Point to Sunlight’s Role

Death rates from heart disease, cancer, stroke, Alzheimer’s, diabetes, and respiratory illness all peak one to three weeks after the shortest day of the year and bottom out after the longest day.

This pattern holds across both infectious and non-infectious causes. The seasonal variation in heart disease deaths alone exceeds total influenza deaths during flu season.

Australia shows the same pattern, but shifted six months—deaths peak in July, their winter. Singapore, 80 miles from the equator with year-round sun, shows no seasonal mortality pattern.

Multiple studies have linked mortality rates to latitude, independent of vitamin D levels, suggesting sunlight itself—particularly its infrared component—plays a direct metabolic role.

Hospitals Are Bringing Patients Outside

Armed with mounting evidence, hospitals worldwide are redesigning care spaces to maximize sunlight exposure.

A $1.5 billion hospital in Footscray, Australia, built ICU beds with direct outdoor access. King’s College Hospital in London invested £2 million to transform its rooftop into a critical care garden where up to six ICU patients can receive treatment surrounded by greenery and natural light.

St. George’s Hospital in London followed suit, creating a neurointensive care rooftop unit. Queen Camilla visited the facility in 2026 to recognize the innovation.

Randomized controlled trials using infrared vests delivering roughly 20–30 watts per square meter (comparable to sitting under a tree) showed 30% reductions in ICU length of stay and improved muscle strength in critically ill COVID-19 patients.

Metabolic Scaling Matches Solar Power Scaling

One of the paper’s most intriguing observations: metabolic rate scales with body mass to the 3/4 power across species from flies to elephants.

Solar power intercepted by an organism also scales to the 3/4 power of mass—nearly identical.

This doesn’t prove causation, but it suggests sunlight could be a universal regulator of metabolic activity across the biosphere, with mitochondria in all organisms tuned to respond to the same infrared wavelengths present in Earth’s solar photon field.

What Makes This Hypothesis Different

Earlier theories proposed infrared light works by activating a photoreceptor in cytochrome c oxidase (complex IV) or by reducing water viscosity around ATP synthase motors.

Seheult’s team doesn’t reject these mechanisms—but argues they’re incomplete.

The Marcus framework explains phenomena earlier models couldn’t: why some infrared wavelengths inhibit rather than enhance mitochondrial activity, why broadband light outperforms monochromatic sources, and why effects persist across vastly different organisms.

The paper is the first to integrate four separate literature streams:

• Mitochondrial electron transfer follows Marcus physics
• Red and near-infrared light alter mitochondrial function
• Water and protein structures affect electron transfer kinetics
• Infrared radiation changes molecular electron transfer rates

“The novelty lies in the mechanistic integration,” Seheult emphasizes, “not in any single component.”

What Comes Next

The hypothesis is testable. Future experiments could measure how different infrared wavelengths alter specific Marcus crossing configurations in isolated mitochondrial complexes, or track real-time changes in reorganization energy using advanced spectroscopy.

If validated, the implications extend far beyond biology. Urban planning, architecture, workplace design, and lighting standards may all need reconsideration.

Seheult introduces a new term: photometabolism—solar-driven, non-photosynthetic modulation of core metabolic processes.

It’s a concept that positions sunlight not as a passive environmental factor, but as an active participant in the biochemistry of life itself.

I believe that this hypothesis if true has major implications for the built environment and how we live and the type of light that we require to live, and I believe it’s one of the major reasons why we need to be treating our patients outside.

Sources

• Jeffery et al. (2025) – Longer wavelengths in sunlight penetrating human tissue
• Ma et al. (2018) – Infrared perturbation of charge separation and recombination
• Sanderson et al. (2018) – Inhibitory modulation of cytochrome c oxidase with near-infrared wavelengths
• Dai et al. (2026) – Infrared stimulation of mitochondrial metabolism in deep-sea yeast
• Hayashi et al. (2010) – Water-mediated electron transfer in iron-sulfur bridges
• Marcus and Sutin (1985) – Electron transfer reactions in chemistry

Not all light sources are created equal. The sun emits a broad spectrum of infrared wavelengths, but one particular photon energy—0.754 electron volts—is especially abundant.

This peak occurs because of the sun’s photosphere, a layer rich in negatively charged hydrogen atoms called hydride ions. These ions absorb higher-energy photons and re-emit them at exactly 0.754 electron volts.

Seheult likens it to dollar bills falling from the sky. While visible light carries the most total energy (like $100 bills), infrared photons are the most numerous (like $1 bills).

The result? A unique atmospheric window that allows these photons to reach Earth’s surface in abundance—and potentially interact with living cells in ways artificial light cannot replicate.

Marcus Electron Transfer: The Physics Behind the Biology

To understand how infrared light affects mitochondria, Seheult’s team turned to Marcus electron transfer theory, pioneered by Nobel laureate Rudolph Marcus in the 1960s.

Electrons don’t jump spontaneously between molecules. They require surrounding proteins, water, and lipids to twist into precise configurations—a process that demands energy called “reorganization energy.”

When infrared light hits these structures, it causes them to vibrate. This shifts the probability that molecules will be in the right arrangement for electron transfer to occur.

• If the crossing point is already accessible: Infrared light can push molecules away from optimal configurations, slowing electron transfer
• If the crossing point requires activation: Infrared light can push molecules toward optimal configurations, speeding electron transfer

This explains a puzzling finding from earlier studies: different infrared wavelengths can either increase or decrease mitochondrial activity.

Experiments Confirm the Mechanism

A 2018 study by Ma and colleagues tested this exact principle. Researchers built a custom molecule and used mid-infrared light to excite vibrational modes.

They found infrared light slowed forward electron transfer but accelerated backward transfer—precisely what Marcus theory predicts when nuclear orientations are shifted along energy curves.

IR excitation increases the probability of donor and acceptor energies to remain in degeneracy, resulting in IR-induced electron transfer rate enhancement.

Seheult notes he and co-author Dr. Robert Fosbury spoke with Marcus himself—just months before the scientist passed away at age 102—to discuss their hypothesis.

Deep-Sea Yeast Thrives on Infrared Light—Without Photosynthesis

Perhaps the most striking evidence comes from an unexpected source: yeast living near hydrothermal vents at the bottom of the ocean.

A 2026 study by Dai and colleagues isolated yeast from sediments near a “black smoker” chimney in the central Indian Ocean, more than half a meter from superheated mineral plumes reaching 378°C.

When researchers exposed these yeast cultures to near-infrared light (810–1050 nm) in temperature-controlled conditions, growth increased dramatically compared to dark controls—even though the yeast cannot photosynthesize.

Infrared light outperformed glucose. Adding glucose increased biomass by only 1.3-fold (not statistically significant), while 880-nanometer infrared light produced a threefold increase.

When researchers blocked cytochrome c oxidase (complex IV in mitochondria), near-infrared-stimulated growth dropped by 44%—suggesting the effect operates directly on mitochondrial machinery.

Cold Temperatures, Warm Light

Even more remarkable: infrared light allowed yeast to grow at cooler temperatures where dark controls remained dormant.

At 20°C, yeast exposed to 880-nanometer light grew vigorously while dark controls showed minimal activity. The effective activation energy dropped from 12 kilocalories per mole to just 2 kilocalories per mole.

Infrared light was making up for the cold temperatures by supplying vibrational activation rather than thermal activation.

Proteomics revealed the most upregulated protein after infrared exposure was a mitochondrial ribosomal protein (MRPs8), increased 6.7-fold.

Why Broadband Sunlight May Beat Monochromatic LEDs

Clinical studies using single-wavelength infrared devices have shown benefits—from reducing ICU length of stay to improving muscle strength in COVID-19 patients.

But Seheult’s hypothesis suggests broadband infrared from the sun may be even more effective.

“Sunlight contains a broad spectrum of wavelengths that can interact with many different vibrational modes and electron transfer steps,” he explains, “rather than targeting only one narrow pathway.”

Research from Jeffery’s lab supports this. When comparing monochromatic 850-nanometer light to a 60-watt incandescent bulb (which emits broad-spectrum infrared), the incandescent bulb produced greater improvements in color blindness.

• Monochromatic 850 nm: 9% improvement (head and body), 5% (body only)
• 60W incandescent bulb: 28% improvement, sustained for weeks

The research here aligns with the hypothesis, though direct mechanistic proof in human mitochondria remains to be demonstrated.

The Modern Indoor Environment: A Metabolic Desert?

LED bulbs emit virtually no infrared radiation. Low-emissivity (Low-E) glass windows, designed to improve energy efficiency, block infrared wavelengths.

Seheult measured infrared exposure in his own dining room with windows open: 0.8 watts per square meter.

Step outside under a shade tree with grass reflecting sunlight? 41.9 watts per square meter—more than 50 times higher.

We have set up a situation where outdoors we’re getting plenty of infrared light, versus being indoors where we have Low-E glass blocking it and LED bulbs producing none.

This raises profound questions about whether chronic infrared deficiency could contribute to the rising burden of metabolic diseases, especially among populations spending most of their time indoors.

Seasonal Mortality Patterns Point to Sunlight’s Role

Death rates from heart disease, cancer, stroke, Alzheimer’s, diabetes, and respiratory illness all peak one to three weeks after the shortest day of the year and bottom out after the longest day.

This pattern holds across both infectious and non-infectious causes. The seasonal variation in heart disease deaths alone exceeds total influenza deaths during flu season.

Australia shows the same pattern, but shifted six months—deaths peak in July, their winter. Singapore, 80 miles from the equator with year-round sun, shows no seasonal mortality pattern.

Multiple studies have linked mortality rates to latitude, independent of vitamin D levels, suggesting sunlight itself—particularly its infrared component—plays a direct metabolic role.

Hospitals Are Bringing Patients Outside

Armed with mounting evidence, hospitals worldwide are redesigning care spaces to maximize sunlight exposure.

A $1.5 billion hospital in Footscray, Australia, built ICU beds with direct outdoor access. King’s College Hospital in London invested £2 million to transform its rooftop into a critical care garden where up to six ICU patients can receive treatment surrounded by greenery and natural light.

St. George’s Hospital in London followed suit, creating a neurointensive care rooftop unit. Queen Camilla visited the facility in 2026 to recognize the innovation.

Randomized controlled trials using infrared vests delivering roughly 20–30 watts per square meter (comparable to sitting under a tree) showed 30% reductions in ICU length of stay and improved muscle strength in critically ill COVID-19 patients.

Metabolic Scaling Matches Solar Power Scaling

One of the paper’s most intriguing observations: metabolic rate scales with body mass to the 3/4 power across species from flies to elephants.

Solar power intercepted by an organism also scales to the 3/4 power of mass—nearly identical.

This doesn’t prove causation, but it suggests sunlight could be a universal regulator of metabolic activity across the biosphere, with mitochondria in all organisms tuned to respond to the same infrared wavelengths present in Earth’s solar photon field.

What Makes This Hypothesis Different

Earlier theories proposed infrared light works by activating a photoreceptor in cytochrome c oxidase (complex IV) or by reducing water viscosity around ATP synthase motors.

Seheult’s team doesn’t reject these mechanisms—but argues they’re incomplete.

The Marcus framework explains phenomena earlier models couldn’t: why some infrared wavelengths inhibit rather than enhance mitochondrial activity, why broadband light outperforms monochromatic sources, and why effects persist across vastly different organisms.

The paper is the first to integrate four separate literature streams:

• Mitochondrial electron transfer follows Marcus physics
• Red and near-infrared light alter mitochondrial function
• Water and protein structures affect electron transfer kinetics
• Infrared radiation changes molecular electron transfer rates

“The novelty lies in the mechanistic integration,” Seheult emphasizes, “not in any single component.”

What Comes Next

The hypothesis is testable. Future experiments could measure how different infrared wavelengths alter specific Marcus crossing configurations in isolated mitochondrial complexes, or track real-time changes in reorganization energy using advanced spectroscopy.

If validated, the implications extend far beyond biology. Urban planning, architecture, workplace design, and lighting standards may all need reconsideration.

Seheult introduces a new term: photometabolism—solar-driven, non-photosynthetic modulation of core metabolic processes.

It’s a concept that positions sunlight not as a passive environmental factor, but as an active participant in the biochemistry of life itself.

I believe that this hypothesis if true has major implications for the built environment and how we live and the type of light that we require to live, and I believe it’s one of the major reasons why we need to be treating our patients outside.

Sources

• Jeffery et al. (2025) – Longer wavelengths in sunlight penetrating human tissue
• Ma et al. (2018) – Infrared perturbation of charge separation and recombination
• Sanderson et al. (2018) – Inhibitory modulation of cytochrome c oxidase with near-infrared wavelengths
• Dai et al. (2026) – Infrared stimulation of mitochondrial metabolism in deep-sea yeast
• Hayashi et al. (2010) – Water-mediated electron transfer in iron-sulfur bridges
• Marcus and Sutin (1985) – Electron transfer reactions in chemistry

The Sun’s Special Infrared Signature

Not all light sources are created equal. The sun emits a broad spectrum of infrared wavelengths, but one particular photon energy—0.754 electron volts—is especially abundant.

This peak occurs because of the sun’s photosphere, a layer rich in negatively charged hydrogen atoms called hydride ions. These ions absorb higher-energy photons and re-emit them at exactly 0.754 electron volts.

Seheult likens it to dollar bills falling from the sky. While visible light carries the most total energy (like $100 bills), infrared photons are the most numerous (like $1 bills).

The result? A unique atmospheric window that allows these photons to reach Earth’s surface in abundance—and potentially interact with living cells in ways artificial light cannot replicate.

Marcus Electron Transfer: The Physics Behind the Biology

To understand how infrared light affects mitochondria, Seheult’s team turned to Marcus electron transfer theory, pioneered by Nobel laureate Rudolph Marcus in the 1960s.

Electrons don’t jump spontaneously between molecules. They require surrounding proteins, water, and lipids to twist into precise configurations—a process that demands energy called “reorganization energy.”

When infrared light hits these structures, it causes them to vibrate. This shifts the probability that molecules will be in the right arrangement for electron transfer to occur.

• If the crossing point is already accessible: Infrared light can push molecules away from optimal configurations, slowing electron transfer
• If the crossing point requires activation: Infrared light can push molecules toward optimal configurations, speeding electron transfer

This explains a puzzling finding from earlier studies: different infrared wavelengths can either increase or decrease mitochondrial activity.

Experiments Confirm the Mechanism

A 2018 study by Ma and colleagues tested this exact principle. Researchers built a custom molecule and used mid-infrared light to excite vibrational modes.

They found infrared light slowed forward electron transfer but accelerated backward transfer—precisely what Marcus theory predicts when nuclear orientations are shifted along energy curves.

IR excitation increases the probability of donor and acceptor energies to remain in degeneracy, resulting in IR-induced electron transfer rate enhancement.

Seheult notes he and co-author Dr. Robert Fosbury spoke with Marcus himself—just months before the scientist passed away at age 102—to discuss their hypothesis.

Deep-Sea Yeast Thrives on Infrared Light—Without Photosynthesis

Perhaps the most striking evidence comes from an unexpected source: yeast living near hydrothermal vents at the bottom of the ocean.

A 2026 study by Dai and colleagues isolated yeast from sediments near a “black smoker” chimney in the central Indian Ocean, more than half a meter from superheated mineral plumes reaching 378°C.

When researchers exposed these yeast cultures to near-infrared light (810–1050 nm) in temperature-controlled conditions, growth increased dramatically compared to dark controls—even though the yeast cannot photosynthesize.

Infrared light outperformed glucose. Adding glucose increased biomass by only 1.3-fold (not statistically significant), while 880-nanometer infrared light produced a threefold increase.

When researchers blocked cytochrome c oxidase (complex IV in mitochondria), near-infrared-stimulated growth dropped by 44%—suggesting the effect operates directly on mitochondrial machinery.

Cold Temperatures, Warm Light

Even more remarkable: infrared light allowed yeast to grow at cooler temperatures where dark controls remained dormant.

At 20°C, yeast exposed to 880-nanometer light grew vigorously while dark controls showed minimal activity. The effective activation energy dropped from 12 kilocalories per mole to just 2 kilocalories per mole.

Infrared light was making up for the cold temperatures by supplying vibrational activation rather than thermal activation.

Proteomics revealed the most upregulated protein after infrared exposure was a mitochondrial ribosomal protein (MRPs8), increased 6.7-fold.

Why Broadband Sunlight May Beat Monochromatic LEDs

Clinical studies using single-wavelength infrared devices have shown benefits—from reducing ICU length of stay to improving muscle strength in COVID-19 patients.

But Seheult’s hypothesis suggests broadband infrared from the sun may be even more effective.

“Sunlight contains a broad spectrum of wavelengths that can interact with many different vibrational modes and electron transfer steps,” he explains, “rather than targeting only one narrow pathway.”

Research from Jeffery’s lab supports this. When comparing monochromatic 850-nanometer light to a 60-watt incandescent bulb (which emits broad-spectrum infrared), the incandescent bulb produced greater improvements in color blindness.

• Monochromatic 850 nm: 9% improvement (head and body), 5% (body only)
• 60W incandescent bulb: 28% improvement, sustained for weeks

The research here aligns with the hypothesis, though direct mechanistic proof in human mitochondria remains to be demonstrated.

The Modern Indoor Environment: A Metabolic Desert?

LED bulbs emit virtually no infrared radiation. Low-emissivity (Low-E) glass windows, designed to improve energy efficiency, block infrared wavelengths.

Seheult measured infrared exposure in his own dining room with windows open: 0.8 watts per square meter.

Step outside under a shade tree with grass reflecting sunlight? 41.9 watts per square meter—more than 50 times higher.

We have set up a situation where outdoors we’re getting plenty of infrared light, versus being indoors where we have Low-E glass blocking it and LED bulbs producing none.

This raises profound questions about whether chronic infrared deficiency could contribute to the rising burden of metabolic diseases, especially among populations spending most of their time indoors.

Seasonal Mortality Patterns Point to Sunlight’s Role

Death rates from heart disease, cancer, stroke, Alzheimer’s, diabetes, and respiratory illness all peak one to three weeks after the shortest day of the year and bottom out after the longest day.

This pattern holds across both infectious and non-infectious causes. The seasonal variation in heart disease deaths alone exceeds total influenza deaths during flu season.

Australia shows the same pattern, but shifted six months—deaths peak in July, their winter. Singapore, 80 miles from the equator with year-round sun, shows no seasonal mortality pattern.

Multiple studies have linked mortality rates to latitude, independent of vitamin D levels, suggesting sunlight itself—particularly its infrared component—plays a direct metabolic role.

Hospitals Are Bringing Patients Outside

Armed with mounting evidence, hospitals worldwide are redesigning care spaces to maximize sunlight exposure.

A $1.5 billion hospital in Footscray, Australia, built ICU beds with direct outdoor access. King’s College Hospital in London invested £2 million to transform its rooftop into a critical care garden where up to six ICU patients can receive treatment surrounded by greenery and natural light.

St. George’s Hospital in London followed suit, creating a neurointensive care rooftop unit. Queen Camilla visited the facility in 2026 to recognize the innovation.

Randomized controlled trials using infrared vests delivering roughly 20–30 watts per square meter (comparable to sitting under a tree) showed 30% reductions in ICU length of stay and improved muscle strength in critically ill COVID-19 patients.

Metabolic Scaling Matches Solar Power Scaling

One of the paper’s most intriguing observations: metabolic rate scales with body mass to the 3/4 power across species from flies to elephants.

Solar power intercepted by an organism also scales to the 3/4 power of mass—nearly identical.

This doesn’t prove causation, but it suggests sunlight could be a universal regulator of metabolic activity across the biosphere, with mitochondria in all organisms tuned to respond to the same infrared wavelengths present in Earth’s solar photon field.

What Makes This Hypothesis Different

Earlier theories proposed infrared light works by activating a photoreceptor in cytochrome c oxidase (complex IV) or by reducing water viscosity around ATP synthase motors.

Seheult’s team doesn’t reject these mechanisms—but argues they’re incomplete.

The Marcus framework explains phenomena earlier models couldn’t: why some infrared wavelengths inhibit rather than enhance mitochondrial activity, why broadband light outperforms monochromatic sources, and why effects persist across vastly different organisms.

The paper is the first to integrate four separate literature streams:

• Mitochondrial electron transfer follows Marcus physics
• Red and near-infrared light alter mitochondrial function
• Water and protein structures affect electron transfer kinetics
• Infrared radiation changes molecular electron transfer rates

“The novelty lies in the mechanistic integration,” Seheult emphasizes, “not in any single component.”

What Comes Next

The hypothesis is testable. Future experiments could measure how different infrared wavelengths alter specific Marcus crossing configurations in isolated mitochondrial complexes, or track real-time changes in reorganization energy using advanced spectroscopy.

If validated, the implications extend far beyond biology. Urban planning, architecture, workplace design, and lighting standards may all need reconsideration.

Seheult introduces a new term: photometabolism—solar-driven, non-photosynthetic modulation of core metabolic processes.

It’s a concept that positions sunlight not as a passive environmental factor, but as an active participant in the biochemistry of life itself.

I believe that this hypothesis if true has major implications for the built environment and how we live and the type of light that we require to live, and I believe it’s one of the major reasons why we need to be treating our patients outside.

Sources

• Jeffery et al. (2025) – Longer wavelengths in sunlight penetrating human tissue
• Ma et al. (2018) – Infrared perturbation of charge separation and recombination
• Sanderson et al. (2018) – Inhibitory modulation of cytochrome c oxidase with near-infrared wavelengths
• Dai et al. (2026) – Infrared stimulation of mitochondrial metabolism in deep-sea yeast
• Hayashi et al. (2010) – Water-mediated electron transfer in iron-sulfur bridges
• Marcus and Sutin (1985) – Electron transfer reactions in chemistry

The Sun’s Special Infrared Signature

Not all light sources are created equal. The sun emits a broad spectrum of infrared wavelengths, but one particular photon energy—0.754 electron volts—is especially abundant.

This peak occurs because of the sun’s photosphere, a layer rich in negatively charged hydrogen atoms called hydride ions. These ions absorb higher-energy photons and re-emit them at exactly 0.754 electron volts.

Seheult likens it to dollar bills falling from the sky. While visible light carries the most total energy (like $100 bills), infrared photons are the most numerous (like $1 bills).

The result? A unique atmospheric window that allows these photons to reach Earth’s surface in abundance—and potentially interact with living cells in ways artificial light cannot replicate.

Marcus Electron Transfer: The Physics Behind the Biology

To understand how infrared light affects mitochondria, Seheult’s team turned to Marcus electron transfer theory, pioneered by Nobel laureate Rudolph Marcus in the 1960s.

Electrons don’t jump spontaneously between molecules. They require surrounding proteins, water, and lipids to twist into precise configurations—a process that demands energy called “reorganization energy.”

When infrared light hits these structures, it causes them to vibrate. This shifts the probability that molecules will be in the right arrangement for electron transfer to occur.

• If the crossing point is already accessible: Infrared light can push molecules away from optimal configurations, slowing electron transfer
• If the crossing point requires activation: Infrared light can push molecules toward optimal configurations, speeding electron transfer

This explains a puzzling finding from earlier studies: different infrared wavelengths can either increase or decrease mitochondrial activity.

Experiments Confirm the Mechanism

A 2018 study by Ma and colleagues tested this exact principle. Researchers built a custom molecule and used mid-infrared light to excite vibrational modes.

They found infrared light slowed forward electron transfer but accelerated backward transfer—precisely what Marcus theory predicts when nuclear orientations are shifted along energy curves.

IR excitation increases the probability of donor and acceptor energies to remain in degeneracy, resulting in IR-induced electron transfer rate enhancement.

Seheult notes he and co-author Dr. Robert Fosbury spoke with Marcus himself—just months before the scientist passed away at age 102—to discuss their hypothesis.

Deep-Sea Yeast Thrives on Infrared Light—Without Photosynthesis

Perhaps the most striking evidence comes from an unexpected source: yeast living near hydrothermal vents at the bottom of the ocean.

A 2026 study by Dai and colleagues isolated yeast from sediments near a “black smoker” chimney in the central Indian Ocean, more than half a meter from superheated mineral plumes reaching 378°C.

When researchers exposed these yeast cultures to near-infrared light (810–1050 nm) in temperature-controlled conditions, growth increased dramatically compared to dark controls—even though the yeast cannot photosynthesize.

Infrared light outperformed glucose. Adding glucose increased biomass by only 1.3-fold (not statistically significant), while 880-nanometer infrared light produced a threefold increase.

When researchers blocked cytochrome c oxidase (complex IV in mitochondria), near-infrared-stimulated growth dropped by 44%—suggesting the effect operates directly on mitochondrial machinery.

Cold Temperatures, Warm Light

Even more remarkable: infrared light allowed yeast to grow at cooler temperatures where dark controls remained dormant.

At 20°C, yeast exposed to 880-nanometer light grew vigorously while dark controls showed minimal activity. The effective activation energy dropped from 12 kilocalories per mole to just 2 kilocalories per mole.

Infrared light was making up for the cold temperatures by supplying vibrational activation rather than thermal activation.

Proteomics revealed the most upregulated protein after infrared exposure was a mitochondrial ribosomal protein (MRPs8), increased 6.7-fold.

Why Broadband Sunlight May Beat Monochromatic LEDs

Clinical studies using single-wavelength infrared devices have shown benefits—from reducing ICU length of stay to improving muscle strength in COVID-19 patients.

But Seheult’s hypothesis suggests broadband infrared from the sun may be even more effective.

“Sunlight contains a broad spectrum of wavelengths that can interact with many different vibrational modes and electron transfer steps,” he explains, “rather than targeting only one narrow pathway.”

Research from Jeffery’s lab supports this. When comparing monochromatic 850-nanometer light to a 60-watt incandescent bulb (which emits broad-spectrum infrared), the incandescent bulb produced greater improvements in color blindness.

• Monochromatic 850 nm: 9% improvement (head and body), 5% (body only)
• 60W incandescent bulb: 28% improvement, sustained for weeks

The research here aligns with the hypothesis, though direct mechanistic proof in human mitochondria remains to be demonstrated.

The Modern Indoor Environment: A Metabolic Desert?

LED bulbs emit virtually no infrared radiation. Low-emissivity (Low-E) glass windows, designed to improve energy efficiency, block infrared wavelengths.

Seheult measured infrared exposure in his own dining room with windows open: 0.8 watts per square meter.

Step outside under a shade tree with grass reflecting sunlight? 41.9 watts per square meter—more than 50 times higher.

We have set up a situation where outdoors we’re getting plenty of infrared light, versus being indoors where we have Low-E glass blocking it and LED bulbs producing none.

This raises profound questions about whether chronic infrared deficiency could contribute to the rising burden of metabolic diseases, especially among populations spending most of their time indoors.

Seasonal Mortality Patterns Point to Sunlight’s Role

Death rates from heart disease, cancer, stroke, Alzheimer’s, diabetes, and respiratory illness all peak one to three weeks after the shortest day of the year and bottom out after the longest day.

This pattern holds across both infectious and non-infectious causes. The seasonal variation in heart disease deaths alone exceeds total influenza deaths during flu season.

Australia shows the same pattern, but shifted six months—deaths peak in July, their winter. Singapore, 80 miles from the equator with year-round sun, shows no seasonal mortality pattern.

Multiple studies have linked mortality rates to latitude, independent of vitamin D levels, suggesting sunlight itself—particularly its infrared component—plays a direct metabolic role.

Hospitals Are Bringing Patients Outside

Armed with mounting evidence, hospitals worldwide are redesigning care spaces to maximize sunlight exposure.

A $1.5 billion hospital in Footscray, Australia, built ICU beds with direct outdoor access. King’s College Hospital in London invested £2 million to transform its rooftop into a critical care garden where up to six ICU patients can receive treatment surrounded by greenery and natural light.

St. George’s Hospital in London followed suit, creating a neurointensive care rooftop unit. Queen Camilla visited the facility in 2026 to recognize the innovation.

Randomized controlled trials using infrared vests delivering roughly 20–30 watts per square meter (comparable to sitting under a tree) showed 30% reductions in ICU length of stay and improved muscle strength in critically ill COVID-19 patients.

Metabolic Scaling Matches Solar Power Scaling

One of the paper’s most intriguing observations: metabolic rate scales with body mass to the 3/4 power across species from flies to elephants.

Solar power intercepted by an organism also scales to the 3/4 power of mass—nearly identical.

This doesn’t prove causation, but it suggests sunlight could be a universal regulator of metabolic activity across the biosphere, with mitochondria in all organisms tuned to respond to the same infrared wavelengths present in Earth’s solar photon field.

What Makes This Hypothesis Different

Earlier theories proposed infrared light works by activating a photoreceptor in cytochrome c oxidase (complex IV) or by reducing water viscosity around ATP synthase motors.

Seheult’s team doesn’t reject these mechanisms—but argues they’re incomplete.

The Marcus framework explains phenomena earlier models couldn’t: why some infrared wavelengths inhibit rather than enhance mitochondrial activity, why broadband light outperforms monochromatic sources, and why effects persist across vastly different organisms.

The paper is the first to integrate four separate literature streams:

• Mitochondrial electron transfer follows Marcus physics
• Red and near-infrared light alter mitochondrial function
• Water and protein structures affect electron transfer kinetics
• Infrared radiation changes molecular electron transfer rates

“The novelty lies in the mechanistic integration,” Seheult emphasizes, “not in any single component.”

What Comes Next

The hypothesis is testable. Future experiments could measure how different infrared wavelengths alter specific Marcus crossing configurations in isolated mitochondrial complexes, or track real-time changes in reorganization energy using advanced spectroscopy.

If validated, the implications extend far beyond biology. Urban planning, architecture, workplace design, and lighting standards may all need reconsideration.

Seheult introduces a new term: photometabolism—solar-driven, non-photosynthetic modulation of core metabolic processes.

It’s a concept that positions sunlight not as a passive environmental factor, but as an active participant in the biochemistry of life itself.

I believe that this hypothesis if true has major implications for the built environment and how we live and the type of light that we require to live, and I believe it’s one of the major reasons why we need to be treating our patients outside.

Sources

• Jeffery et al. (2025) – Longer wavelengths in sunlight penetrating human tissue
• Ma et al. (2018) – Infrared perturbation of charge separation and recombination
• Sanderson et al. (2018) – Inhibitory modulation of cytochrome c oxidase with near-infrared wavelengths
• Dai et al. (2026) – Infrared stimulation of mitochondrial metabolism in deep-sea yeast
• Hayashi et al. (2010) – Water-mediated electron transfer in iron-sulfur bridges
• Marcus and Sutin (1985) – Electron transfer reactions in chemistry

This discovery opens the door to a startling possibility: infrared photons from the sun may be reaching mitochondria deep inside the body and influencing their activity in real time.

The Sun’s Special Infrared Signature

Not all light sources are created equal. The sun emits a broad spectrum of infrared wavelengths, but one particular photon energy—0.754 electron volts—is especially abundant.

This peak occurs because of the sun’s photosphere, a layer rich in negatively charged hydrogen atoms called hydride ions. These ions absorb higher-energy photons and re-emit them at exactly 0.754 electron volts.

Seheult likens it to dollar bills falling from the sky. While visible light carries the most total energy (like $100 bills), infrared photons are the most numerous (like $1 bills).

The result? A unique atmospheric window that allows these photons to reach Earth’s surface in abundance—and potentially interact with living cells in ways artificial light cannot replicate.

Marcus Electron Transfer: The Physics Behind the Biology

To understand how infrared light affects mitochondria, Seheult’s team turned to Marcus electron transfer theory, pioneered by Nobel laureate Rudolph Marcus in the 1960s.

Electrons don’t jump spontaneously between molecules. They require surrounding proteins, water, and lipids to twist into precise configurations—a process that demands energy called “reorganization energy.”

When infrared light hits these structures, it causes them to vibrate. This shifts the probability that molecules will be in the right arrangement for electron transfer to occur.

• If the crossing point is already accessible: Infrared light can push molecules away from optimal configurations, slowing electron transfer
• If the crossing point requires activation: Infrared light can push molecules toward optimal configurations, speeding electron transfer

This explains a puzzling finding from earlier studies: different infrared wavelengths can either increase or decrease mitochondrial activity.

Experiments Confirm the Mechanism

A 2018 study by Ma and colleagues tested this exact principle. Researchers built a custom molecule and used mid-infrared light to excite vibrational modes.

They found infrared light slowed forward electron transfer but accelerated backward transfer—precisely what Marcus theory predicts when nuclear orientations are shifted along energy curves.

IR excitation increases the probability of donor and acceptor energies to remain in degeneracy, resulting in IR-induced electron transfer rate enhancement.

Seheult notes he and co-author Dr. Robert Fosbury spoke with Marcus himself—just months before the scientist passed away at age 102—to discuss their hypothesis.

Deep-Sea Yeast Thrives on Infrared Light—Without Photosynthesis

Perhaps the most striking evidence comes from an unexpected source: yeast living near hydrothermal vents at the bottom of the ocean.

A 2026 study by Dai and colleagues isolated yeast from sediments near a “black smoker” chimney in the central Indian Ocean, more than half a meter from superheated mineral plumes reaching 378°C.

When researchers exposed these yeast cultures to near-infrared light (810–1050 nm) in temperature-controlled conditions, growth increased dramatically compared to dark controls—even though the yeast cannot photosynthesize.

Infrared light outperformed glucose. Adding glucose increased biomass by only 1.3-fold (not statistically significant), while 880-nanometer infrared light produced a threefold increase.

When researchers blocked cytochrome c oxidase (complex IV in mitochondria), near-infrared-stimulated growth dropped by 44%—suggesting the effect operates directly on mitochondrial machinery.

Cold Temperatures, Warm Light

Even more remarkable: infrared light allowed yeast to grow at cooler temperatures where dark controls remained dormant.

At 20°C, yeast exposed to 880-nanometer light grew vigorously while dark controls showed minimal activity. The effective activation energy dropped from 12 kilocalories per mole to just 2 kilocalories per mole.

Infrared light was making up for the cold temperatures by supplying vibrational activation rather than thermal activation.

Proteomics revealed the most upregulated protein after infrared exposure was a mitochondrial ribosomal protein (MRPs8), increased 6.7-fold.

Why Broadband Sunlight May Beat Monochromatic LEDs

Clinical studies using single-wavelength infrared devices have shown benefits—from reducing ICU length of stay to improving muscle strength in COVID-19 patients.

But Seheult’s hypothesis suggests broadband infrared from the sun may be even more effective.

“Sunlight contains a broad spectrum of wavelengths that can interact with many different vibrational modes and electron transfer steps,” he explains, “rather than targeting only one narrow pathway.”

Research from Jeffery’s lab supports this. When comparing monochromatic 850-nanometer light to a 60-watt incandescent bulb (which emits broad-spectrum infrared), the incandescent bulb produced greater improvements in color blindness.

• Monochromatic 850 nm: 9% improvement (head and body), 5% (body only)
• 60W incandescent bulb: 28% improvement, sustained for weeks

The research here aligns with the hypothesis, though direct mechanistic proof in human mitochondria remains to be demonstrated.

The Modern Indoor Environment: A Metabolic Desert?

LED bulbs emit virtually no infrared radiation. Low-emissivity (Low-E) glass windows, designed to improve energy efficiency, block infrared wavelengths.

Seheult measured infrared exposure in his own dining room with windows open: 0.8 watts per square meter.

Step outside under a shade tree with grass reflecting sunlight? 41.9 watts per square meter—more than 50 times higher.

We have set up a situation where outdoors we’re getting plenty of infrared light, versus being indoors where we have Low-E glass blocking it and LED bulbs producing none.

This raises profound questions about whether chronic infrared deficiency could contribute to the rising burden of metabolic diseases, especially among populations spending most of their time indoors.

Seasonal Mortality Patterns Point to Sunlight’s Role

Death rates from heart disease, cancer, stroke, Alzheimer’s, diabetes, and respiratory illness all peak one to three weeks after the shortest day of the year and bottom out after the longest day.

This pattern holds across both infectious and non-infectious causes. The seasonal variation in heart disease deaths alone exceeds total influenza deaths during flu season.

Australia shows the same pattern, but shifted six months—deaths peak in July, their winter. Singapore, 80 miles from the equator with year-round sun, shows no seasonal mortality pattern.

Multiple studies have linked mortality rates to latitude, independent of vitamin D levels, suggesting sunlight itself—particularly its infrared component—plays a direct metabolic role.

Hospitals Are Bringing Patients Outside

Armed with mounting evidence, hospitals worldwide are redesigning care spaces to maximize sunlight exposure.

A $1.5 billion hospital in Footscray, Australia, built ICU beds with direct outdoor access. King’s College Hospital in London invested £2 million to transform its rooftop into a critical care garden where up to six ICU patients can receive treatment surrounded by greenery and natural light.

St. George’s Hospital in London followed suit, creating a neurointensive care rooftop unit. Queen Camilla visited the facility in 2026 to recognize the innovation.

Randomized controlled trials using infrared vests delivering roughly 20–30 watts per square meter (comparable to sitting under a tree) showed 30% reductions in ICU length of stay and improved muscle strength in critically ill COVID-19 patients.

Metabolic Scaling Matches Solar Power Scaling

One of the paper’s most intriguing observations: metabolic rate scales with body mass to the 3/4 power across species from flies to elephants.

Solar power intercepted by an organism also scales to the 3/4 power of mass—nearly identical.

This doesn’t prove causation, but it suggests sunlight could be a universal regulator of metabolic activity across the biosphere, with mitochondria in all organisms tuned to respond to the same infrared wavelengths present in Earth’s solar photon field.

What Makes This Hypothesis Different

Earlier theories proposed infrared light works by activating a photoreceptor in cytochrome c oxidase (complex IV) or by reducing water viscosity around ATP synthase motors.

Seheult’s team doesn’t reject these mechanisms—but argues they’re incomplete.

The Marcus framework explains phenomena earlier models couldn’t: why some infrared wavelengths inhibit rather than enhance mitochondrial activity, why broadband light outperforms monochromatic sources, and why effects persist across vastly different organisms.

The paper is the first to integrate four separate literature streams:

• Mitochondrial electron transfer follows Marcus physics
• Red and near-infrared light alter mitochondrial function
• Water and protein structures affect electron transfer kinetics
• Infrared radiation changes molecular electron transfer rates

“The novelty lies in the mechanistic integration,” Seheult emphasizes, “not in any single component.”

What Comes Next

The hypothesis is testable. Future experiments could measure how different infrared wavelengths alter specific Marcus crossing configurations in isolated mitochondrial complexes, or track real-time changes in reorganization energy using advanced spectroscopy.

If validated, the implications extend far beyond biology. Urban planning, architecture, workplace design, and lighting standards may all need reconsideration.

Seheult introduces a new term: photometabolism—solar-driven, non-photosynthetic modulation of core metabolic processes.

It’s a concept that positions sunlight not as a passive environmental factor, but as an active participant in the biochemistry of life itself.

I believe that this hypothesis if true has major implications for the built environment and how we live and the type of light that we require to live, and I believe it’s one of the major reasons why we need to be treating our patients outside.

Sources

• Jeffery et al. (2025) – Longer wavelengths in sunlight penetrating human tissue
• Ma et al. (2018) – Infrared perturbation of charge separation and recombination
• Sanderson et al. (2018) – Inhibitory modulation of cytochrome c oxidase with near-infrared wavelengths
• Dai et al. (2026) – Infrared stimulation of mitochondrial metabolism in deep-sea yeast
• Hayashi et al. (2010) – Water-mediated electron transfer in iron-sulfur bridges
• Marcus and Sutin (1985) – Electron transfer reactions in chemistry

This discovery opens the door to a startling possibility: infrared photons from the sun may be reaching mitochondria deep inside the body and influencing their activity in real time.

The Sun’s Special Infrared Signature

Not all light sources are created equal. The sun emits a broad spectrum of infrared wavelengths, but one particular photon energy—0.754 electron volts—is especially abundant.

This peak occurs because of the sun’s photosphere, a layer rich in negatively charged hydrogen atoms called hydride ions. These ions absorb higher-energy photons and re-emit them at exactly 0.754 electron volts.

Seheult likens it to dollar bills falling from the sky. While visible light carries the most total energy (like $100 bills), infrared photons are the most numerous (like $1 bills).

The result? A unique atmospheric window that allows these photons to reach Earth’s surface in abundance—and potentially interact with living cells in ways artificial light cannot replicate.

Marcus Electron Transfer: The Physics Behind the Biology

To understand how infrared light affects mitochondria, Seheult’s team turned to Marcus electron transfer theory, pioneered by Nobel laureate Rudolph Marcus in the 1960s.

Electrons don’t jump spontaneously between molecules. They require surrounding proteins, water, and lipids to twist into precise configurations—a process that demands energy called “reorganization energy.”

When infrared light hits these structures, it causes them to vibrate. This shifts the probability that molecules will be in the right arrangement for electron transfer to occur.

• If the crossing point is already accessible: Infrared light can push molecules away from optimal configurations, slowing electron transfer
• If the crossing point requires activation: Infrared light can push molecules toward optimal configurations, speeding electron transfer

This explains a puzzling finding from earlier studies: different infrared wavelengths can either increase or decrease mitochondrial activity.

Experiments Confirm the Mechanism

A 2018 study by Ma and colleagues tested this exact principle. Researchers built a custom molecule and used mid-infrared light to excite vibrational modes.

They found infrared light slowed forward electron transfer but accelerated backward transfer—precisely what Marcus theory predicts when nuclear orientations are shifted along energy curves.

IR excitation increases the probability of donor and acceptor energies to remain in degeneracy, resulting in IR-induced electron transfer rate enhancement.

Seheult notes he and co-author Dr. Robert Fosbury spoke with Marcus himself—just months before the scientist passed away at age 102—to discuss their hypothesis.

Deep-Sea Yeast Thrives on Infrared Light—Without Photosynthesis

Perhaps the most striking evidence comes from an unexpected source: yeast living near hydrothermal vents at the bottom of the ocean.

A 2026 study by Dai and colleagues isolated yeast from sediments near a “black smoker” chimney in the central Indian Ocean, more than half a meter from superheated mineral plumes reaching 378°C.

When researchers exposed these yeast cultures to near-infrared light (810–1050 nm) in temperature-controlled conditions, growth increased dramatically compared to dark controls—even though the yeast cannot photosynthesize.

Infrared light outperformed glucose. Adding glucose increased biomass by only 1.3-fold (not statistically significant), while 880-nanometer infrared light produced a threefold increase.

When researchers blocked cytochrome c oxidase (complex IV in mitochondria), near-infrared-stimulated growth dropped by 44%—suggesting the effect operates directly on mitochondrial machinery.

Cold Temperatures, Warm Light

Even more remarkable: infrared light allowed yeast to grow at cooler temperatures where dark controls remained dormant.

At 20°C, yeast exposed to 880-nanometer light grew vigorously while dark controls showed minimal activity. The effective activation energy dropped from 12 kilocalories per mole to just 2 kilocalories per mole.

Infrared light was making up for the cold temperatures by supplying vibrational activation rather than thermal activation.

Proteomics revealed the most upregulated protein after infrared exposure was a mitochondrial ribosomal protein (MRPs8), increased 6.7-fold.

Why Broadband Sunlight May Beat Monochromatic LEDs

Clinical studies using single-wavelength infrared devices have shown benefits—from reducing ICU length of stay to improving muscle strength in COVID-19 patients.

But Seheult’s hypothesis suggests broadband infrared from the sun may be even more effective.

“Sunlight contains a broad spectrum of wavelengths that can interact with many different vibrational modes and electron transfer steps,” he explains, “rather than targeting only one narrow pathway.”

Research from Jeffery’s lab supports this. When comparing monochromatic 850-nanometer light to a 60-watt incandescent bulb (which emits broad-spectrum infrared), the incandescent bulb produced greater improvements in color blindness.

• Monochromatic 850 nm: 9% improvement (head and body), 5% (body only)
• 60W incandescent bulb: 28% improvement, sustained for weeks

The research here aligns with the hypothesis, though direct mechanistic proof in human mitochondria remains to be demonstrated.

The Modern Indoor Environment: A Metabolic Desert?

LED bulbs emit virtually no infrared radiation. Low-emissivity (Low-E) glass windows, designed to improve energy efficiency, block infrared wavelengths.

Seheult measured infrared exposure in his own dining room with windows open: 0.8 watts per square meter.

Step outside under a shade tree with grass reflecting sunlight? 41.9 watts per square meter—more than 50 times higher.

We have set up a situation where outdoors we’re getting plenty of infrared light, versus being indoors where we have Low-E glass blocking it and LED bulbs producing none.

This raises profound questions about whether chronic infrared deficiency could contribute to the rising burden of metabolic diseases, especially among populations spending most of their time indoors.

Seasonal Mortality Patterns Point to Sunlight’s Role

Death rates from heart disease, cancer, stroke, Alzheimer’s, diabetes, and respiratory illness all peak one to three weeks after the shortest day of the year and bottom out after the longest day.

This pattern holds across both infectious and non-infectious causes. The seasonal variation in heart disease deaths alone exceeds total influenza deaths during flu season.

Australia shows the same pattern, but shifted six months—deaths peak in July, their winter. Singapore, 80 miles from the equator with year-round sun, shows no seasonal mortality pattern.

Multiple studies have linked mortality rates to latitude, independent of vitamin D levels, suggesting sunlight itself—particularly its infrared component—plays a direct metabolic role.

Hospitals Are Bringing Patients Outside

Armed with mounting evidence, hospitals worldwide are redesigning care spaces to maximize sunlight exposure.

A $1.5 billion hospital in Footscray, Australia, built ICU beds with direct outdoor access. King’s College Hospital in London invested £2 million to transform its rooftop into a critical care garden where up to six ICU patients can receive treatment surrounded by greenery and natural light.

St. George’s Hospital in London followed suit, creating a neurointensive care rooftop unit. Queen Camilla visited the facility in 2026 to recognize the innovation.

Randomized controlled trials using infrared vests delivering roughly 20–30 watts per square meter (comparable to sitting under a tree) showed 30% reductions in ICU length of stay and improved muscle strength in critically ill COVID-19 patients.

Metabolic Scaling Matches Solar Power Scaling

One of the paper’s most intriguing observations: metabolic rate scales with body mass to the 3/4 power across species from flies to elephants.

Solar power intercepted by an organism also scales to the 3/4 power of mass—nearly identical.

This doesn’t prove causation, but it suggests sunlight could be a universal regulator of metabolic activity across the biosphere, with mitochondria in all organisms tuned to respond to the same infrared wavelengths present in Earth’s solar photon field.

What Makes This Hypothesis Different

Earlier theories proposed infrared light works by activating a photoreceptor in cytochrome c oxidase (complex IV) or by reducing water viscosity around ATP synthase motors.

Seheult’s team doesn’t reject these mechanisms—but argues they’re incomplete.

The Marcus framework explains phenomena earlier models couldn’t: why some infrared wavelengths inhibit rather than enhance mitochondrial activity, why broadband light outperforms monochromatic sources, and why effects persist across vastly different organisms.

The paper is the first to integrate four separate literature streams:

• Mitochondrial electron transfer follows Marcus physics
• Red and near-infrared light alter mitochondrial function
• Water and protein structures affect electron transfer kinetics
• Infrared radiation changes molecular electron transfer rates

“The novelty lies in the mechanistic integration,” Seheult emphasizes, “not in any single component.”

What Comes Next

The hypothesis is testable. Future experiments could measure how different infrared wavelengths alter specific Marcus crossing configurations in isolated mitochondrial complexes, or track real-time changes in reorganization energy using advanced spectroscopy.

If validated, the implications extend far beyond biology. Urban planning, architecture, workplace design, and lighting standards may all need reconsideration.

Seheult introduces a new term: photometabolism—solar-driven, non-photosynthetic modulation of core metabolic processes.

It’s a concept that positions sunlight not as a passive environmental factor, but as an active participant in the biochemistry of life itself.

I believe that this hypothesis if true has major implications for the built environment and how we live and the type of light that we require to live, and I believe it’s one of the major reasons why we need to be treating our patients outside.

Sources

• Jeffery et al. (2025) – Longer wavelengths in sunlight penetrating human tissue
• Ma et al. (2018) – Infrared perturbation of charge separation and recombination
• Sanderson et al. (2018) – Inhibitory modulation of cytochrome c oxidase with near-infrared wavelengths
• Dai et al. (2026) – Infrared stimulation of mitochondrial metabolism in deep-sea yeast
• Hayashi et al. (2010) – Water-mediated electron transfer in iron-sulfur bridges
• Marcus and Sutin (1985) – Electron transfer reactions in chemistry

In one striking experiment, 850-nanometer light was shown passing through a human hand with measurable intensity on the other side. Infrared wavelengths between 750 and 1,000 nanometers can even penetrate clothing.

This discovery opens the door to a startling possibility: infrared photons from the sun may be reaching mitochondria deep inside the body and influencing their activity in real time.

The Sun’s Special Infrared Signature

Not all light sources are created equal. The sun emits a broad spectrum of infrared wavelengths, but one particular photon energy—0.754 electron volts—is especially abundant.

This peak occurs because of the sun’s photosphere, a layer rich in negatively charged hydrogen atoms called hydride ions. These ions absorb higher-energy photons and re-emit them at exactly 0.754 electron volts.

Seheult likens it to dollar bills falling from the sky. While visible light carries the most total energy (like $100 bills), infrared photons are the most numerous (like $1 bills).

The result? A unique atmospheric window that allows these photons to reach Earth’s surface in abundance—and potentially interact with living cells in ways artificial light cannot replicate.

Marcus Electron Transfer: The Physics Behind the Biology

To understand how infrared light affects mitochondria, Seheult’s team turned to Marcus electron transfer theory, pioneered by Nobel laureate Rudolph Marcus in the 1960s.

Electrons don’t jump spontaneously between molecules. They require surrounding proteins, water, and lipids to twist into precise configurations—a process that demands energy called “reorganization energy.”

When infrared light hits these structures, it causes them to vibrate. This shifts the probability that molecules will be in the right arrangement for electron transfer to occur.

• If the crossing point is already accessible: Infrared light can push molecules away from optimal configurations, slowing electron transfer
• If the crossing point requires activation: Infrared light can push molecules toward optimal configurations, speeding electron transfer

This explains a puzzling finding from earlier studies: different infrared wavelengths can either increase or decrease mitochondrial activity.

Experiments Confirm the Mechanism

A 2018 study by Ma and colleagues tested this exact principle. Researchers built a custom molecule and used mid-infrared light to excite vibrational modes.

They found infrared light slowed forward electron transfer but accelerated backward transfer—precisely what Marcus theory predicts when nuclear orientations are shifted along energy curves.

IR excitation increases the probability of donor and acceptor energies to remain in degeneracy, resulting in IR-induced electron transfer rate enhancement.

Seheult notes he and co-author Dr. Robert Fosbury spoke with Marcus himself—just months before the scientist passed away at age 102—to discuss their hypothesis.

Deep-Sea Yeast Thrives on Infrared Light—Without Photosynthesis

Perhaps the most striking evidence comes from an unexpected source: yeast living near hydrothermal vents at the bottom of the ocean.

A 2026 study by Dai and colleagues isolated yeast from sediments near a “black smoker” chimney in the central Indian Ocean, more than half a meter from superheated mineral plumes reaching 378°C.

When researchers exposed these yeast cultures to near-infrared light (810–1050 nm) in temperature-controlled conditions, growth increased dramatically compared to dark controls—even though the yeast cannot photosynthesize.

Infrared light outperformed glucose. Adding glucose increased biomass by only 1.3-fold (not statistically significant), while 880-nanometer infrared light produced a threefold increase.

When researchers blocked cytochrome c oxidase (complex IV in mitochondria), near-infrared-stimulated growth dropped by 44%—suggesting the effect operates directly on mitochondrial machinery.

Cold Temperatures, Warm Light

Even more remarkable: infrared light allowed yeast to grow at cooler temperatures where dark controls remained dormant.

At 20°C, yeast exposed to 880-nanometer light grew vigorously while dark controls showed minimal activity. The effective activation energy dropped from 12 kilocalories per mole to just 2 kilocalories per mole.

Infrared light was making up for the cold temperatures by supplying vibrational activation rather than thermal activation.

Proteomics revealed the most upregulated protein after infrared exposure was a mitochondrial ribosomal protein (MRPs8), increased 6.7-fold.

Why Broadband Sunlight May Beat Monochromatic LEDs

Clinical studies using single-wavelength infrared devices have shown benefits—from reducing ICU length of stay to improving muscle strength in COVID-19 patients.

But Seheult’s hypothesis suggests broadband infrared from the sun may be even more effective.

“Sunlight contains a broad spectrum of wavelengths that can interact with many different vibrational modes and electron transfer steps,” he explains, “rather than targeting only one narrow pathway.”

Research from Jeffery’s lab supports this. When comparing monochromatic 850-nanometer light to a 60-watt incandescent bulb (which emits broad-spectrum infrared), the incandescent bulb produced greater improvements in color blindness.

• Monochromatic 850 nm: 9% improvement (head and body), 5% (body only)
• 60W incandescent bulb: 28% improvement, sustained for weeks

The research here aligns with the hypothesis, though direct mechanistic proof in human mitochondria remains to be demonstrated.

The Modern Indoor Environment: A Metabolic Desert?

LED bulbs emit virtually no infrared radiation. Low-emissivity (Low-E) glass windows, designed to improve energy efficiency, block infrared wavelengths.

Seheult measured infrared exposure in his own dining room with windows open: 0.8 watts per square meter.

Step outside under a shade tree with grass reflecting sunlight? 41.9 watts per square meter—more than 50 times higher.

We have set up a situation where outdoors we’re getting plenty of infrared light, versus being indoors where we have Low-E glass blocking it and LED bulbs producing none.

This raises profound questions about whether chronic infrared deficiency could contribute to the rising burden of metabolic diseases, especially among populations spending most of their time indoors.

Seasonal Mortality Patterns Point to Sunlight’s Role

Death rates from heart disease, cancer, stroke, Alzheimer’s, diabetes, and respiratory illness all peak one to three weeks after the shortest day of the year and bottom out after the longest day.

This pattern holds across both infectious and non-infectious causes. The seasonal variation in heart disease deaths alone exceeds total influenza deaths during flu season.

Australia shows the same pattern, but shifted six months—deaths peak in July, their winter. Singapore, 80 miles from the equator with year-round sun, shows no seasonal mortality pattern.

Multiple studies have linked mortality rates to latitude, independent of vitamin D levels, suggesting sunlight itself—particularly its infrared component—plays a direct metabolic role.

Hospitals Are Bringing Patients Outside

Armed with mounting evidence, hospitals worldwide are redesigning care spaces to maximize sunlight exposure.

A $1.5 billion hospital in Footscray, Australia, built ICU beds with direct outdoor access. King’s College Hospital in London invested £2 million to transform its rooftop into a critical care garden where up to six ICU patients can receive treatment surrounded by greenery and natural light.

St. George’s Hospital in London followed suit, creating a neurointensive care rooftop unit. Queen Camilla visited the facility in 2026 to recognize the innovation.

Randomized controlled trials using infrared vests delivering roughly 20–30 watts per square meter (comparable to sitting under a tree) showed 30% reductions in ICU length of stay and improved muscle strength in critically ill COVID-19 patients.

Metabolic Scaling Matches Solar Power Scaling

One of the paper’s most intriguing observations: metabolic rate scales with body mass to the 3/4 power across species from flies to elephants.

Solar power intercepted by an organism also scales to the 3/4 power of mass—nearly identical.

This doesn’t prove causation, but it suggests sunlight could be a universal regulator of metabolic activity across the biosphere, with mitochondria in all organisms tuned to respond to the same infrared wavelengths present in Earth’s solar photon field.

What Makes This Hypothesis Different

Earlier theories proposed infrared light works by activating a photoreceptor in cytochrome c oxidase (complex IV) or by reducing water viscosity around ATP synthase motors.

Seheult’s team doesn’t reject these mechanisms—but argues they’re incomplete.

The Marcus framework explains phenomena earlier models couldn’t: why some infrared wavelengths inhibit rather than enhance mitochondrial activity, why broadband light outperforms monochromatic sources, and why effects persist across vastly different organisms.

The paper is the first to integrate four separate literature streams:

• Mitochondrial electron transfer follows Marcus physics
• Red and near-infrared light alter mitochondrial function
• Water and protein structures affect electron transfer kinetics
• Infrared radiation changes molecular electron transfer rates

“The novelty lies in the mechanistic integration,” Seheult emphasizes, “not in any single component.”

What Comes Next

The hypothesis is testable. Future experiments could measure how different infrared wavelengths alter specific Marcus crossing configurations in isolated mitochondrial complexes, or track real-time changes in reorganization energy using advanced spectroscopy.

If validated, the implications extend far beyond biology. Urban planning, architecture, workplace design, and lighting standards may all need reconsideration.

Seheult introduces a new term: photometabolism—solar-driven, non-photosynthetic modulation of core metabolic processes.

It’s a concept that positions sunlight not as a passive environmental factor, but as an active participant in the biochemistry of life itself.

I believe that this hypothesis if true has major implications for the built environment and how we live and the type of light that we require to live, and I believe it’s one of the major reasons why we need to be treating our patients outside.

Sources

• Jeffery et al. (2025) – Longer wavelengths in sunlight penetrating human tissue
• Ma et al. (2018) – Infrared perturbation of charge separation and recombination
• Sanderson et al. (2018) – Inhibitory modulation of cytochrome c oxidase with near-infrared wavelengths
• Dai et al. (2026) – Infrared stimulation of mitochondrial metabolism in deep-sea yeast
• Hayashi et al. (2010) – Water-mediated electron transfer in iron-sulfur bridges
• Marcus and Sutin (1985) – Electron transfer reactions in chemistry

In one striking experiment, 850-nanometer light was shown passing through a human hand with measurable intensity on the other side. Infrared wavelengths between 750 and 1,000 nanometers can even penetrate clothing.

This discovery opens the door to a startling possibility: infrared photons from the sun may be reaching mitochondria deep inside the body and influencing their activity in real time.

The Sun’s Special Infrared Signature

Not all light sources are created equal. The sun emits a broad spectrum of infrared wavelengths, but one particular photon energy—0.754 electron volts—is especially abundant.

This peak occurs because of the sun’s photosphere, a layer rich in negatively charged hydrogen atoms called hydride ions. These ions absorb higher-energy photons and re-emit them at exactly 0.754 electron volts.

Seheult likens it to dollar bills falling from the sky. While visible light carries the most total energy (like $100 bills), infrared photons are the most numerous (like $1 bills).

The result? A unique atmospheric window that allows these photons to reach Earth’s surface in abundance—and potentially interact with living cells in ways artificial light cannot replicate.

Marcus Electron Transfer: The Physics Behind the Biology

To understand how infrared light affects mitochondria, Seheult’s team turned to Marcus electron transfer theory, pioneered by Nobel laureate Rudolph Marcus in the 1960s.

Electrons don’t jump spontaneously between molecules. They require surrounding proteins, water, and lipids to twist into precise configurations—a process that demands energy called “reorganization energy.”

When infrared light hits these structures, it causes them to vibrate. This shifts the probability that molecules will be in the right arrangement for electron transfer to occur.

• If the crossing point is already accessible: Infrared light can push molecules away from optimal configurations, slowing electron transfer
• If the crossing point requires activation: Infrared light can push molecules toward optimal configurations, speeding electron transfer

This explains a puzzling finding from earlier studies: different infrared wavelengths can either increase or decrease mitochondrial activity.

Experiments Confirm the Mechanism

A 2018 study by Ma and colleagues tested this exact principle. Researchers built a custom molecule and used mid-infrared light to excite vibrational modes.

They found infrared light slowed forward electron transfer but accelerated backward transfer—precisely what Marcus theory predicts when nuclear orientations are shifted along energy curves.

IR excitation increases the probability of donor and acceptor energies to remain in degeneracy, resulting in IR-induced electron transfer rate enhancement.

Seheult notes he and co-author Dr. Robert Fosbury spoke with Marcus himself—just months before the scientist passed away at age 102—to discuss their hypothesis.

Deep-Sea Yeast Thrives on Infrared Light—Without Photosynthesis

Perhaps the most striking evidence comes from an unexpected source: yeast living near hydrothermal vents at the bottom of the ocean.

A 2026 study by Dai and colleagues isolated yeast from sediments near a “black smoker” chimney in the central Indian Ocean, more than half a meter from superheated mineral plumes reaching 378°C.

When researchers exposed these yeast cultures to near-infrared light (810–1050 nm) in temperature-controlled conditions, growth increased dramatically compared to dark controls—even though the yeast cannot photosynthesize.

Infrared light outperformed glucose. Adding glucose increased biomass by only 1.3-fold (not statistically significant), while 880-nanometer infrared light produced a threefold increase.

When researchers blocked cytochrome c oxidase (complex IV in mitochondria), near-infrared-stimulated growth dropped by 44%—suggesting the effect operates directly on mitochondrial machinery.

Cold Temperatures, Warm Light

Even more remarkable: infrared light allowed yeast to grow at cooler temperatures where dark controls remained dormant.

At 20°C, yeast exposed to 880-nanometer light grew vigorously while dark controls showed minimal activity. The effective activation energy dropped from 12 kilocalories per mole to just 2 kilocalories per mole.

Infrared light was making up for the cold temperatures by supplying vibrational activation rather than thermal activation.

Proteomics revealed the most upregulated protein after infrared exposure was a mitochondrial ribosomal protein (MRPs8), increased 6.7-fold.

Why Broadband Sunlight May Beat Monochromatic LEDs

Clinical studies using single-wavelength infrared devices have shown benefits—from reducing ICU length of stay to improving muscle strength in COVID-19 patients.

But Seheult’s hypothesis suggests broadband infrared from the sun may be even more effective.

“Sunlight contains a broad spectrum of wavelengths that can interact with many different vibrational modes and electron transfer steps,” he explains, “rather than targeting only one narrow pathway.”

Research from Jeffery’s lab supports this. When comparing monochromatic 850-nanometer light to a 60-watt incandescent bulb (which emits broad-spectrum infrared), the incandescent bulb produced greater improvements in color blindness.

• Monochromatic 850 nm: 9% improvement (head and body), 5% (body only)
• 60W incandescent bulb: 28% improvement, sustained for weeks

The research here aligns with the hypothesis, though direct mechanistic proof in human mitochondria remains to be demonstrated.

The Modern Indoor Environment: A Metabolic Desert?

LED bulbs emit virtually no infrared radiation. Low-emissivity (Low-E) glass windows, designed to improve energy efficiency, block infrared wavelengths.

Seheult measured infrared exposure in his own dining room with windows open: 0.8 watts per square meter.

Step outside under a shade tree with grass reflecting sunlight? 41.9 watts per square meter—more than 50 times higher.

We have set up a situation where outdoors we’re getting plenty of infrared light, versus being indoors where we have Low-E glass blocking it and LED bulbs producing none.

This raises profound questions about whether chronic infrared deficiency could contribute to the rising burden of metabolic diseases, especially among populations spending most of their time indoors.

Seasonal Mortality Patterns Point to Sunlight’s Role

Death rates from heart disease, cancer, stroke, Alzheimer’s, diabetes, and respiratory illness all peak one to three weeks after the shortest day of the year and bottom out after the longest day.

This pattern holds across both infectious and non-infectious causes. The seasonal variation in heart disease deaths alone exceeds total influenza deaths during flu season.

Australia shows the same pattern, but shifted six months—deaths peak in July, their winter. Singapore, 80 miles from the equator with year-round sun, shows no seasonal mortality pattern.

Multiple studies have linked mortality rates to latitude, independent of vitamin D levels, suggesting sunlight itself—particularly its infrared component—plays a direct metabolic role.

Hospitals Are Bringing Patients Outside

Armed with mounting evidence, hospitals worldwide are redesigning care spaces to maximize sunlight exposure.

A $1.5 billion hospital in Footscray, Australia, built ICU beds with direct outdoor access. King’s College Hospital in London invested £2 million to transform its rooftop into a critical care garden where up to six ICU patients can receive treatment surrounded by greenery and natural light.

St. George’s Hospital in London followed suit, creating a neurointensive care rooftop unit. Queen Camilla visited the facility in 2026 to recognize the innovation.

Randomized controlled trials using infrared vests delivering roughly 20–30 watts per square meter (comparable to sitting under a tree) showed 30% reductions in ICU length of stay and improved muscle strength in critically ill COVID-19 patients.

Metabolic Scaling Matches Solar Power Scaling

One of the paper’s most intriguing observations: metabolic rate scales with body mass to the 3/4 power across species from flies to elephants.

Solar power intercepted by an organism also scales to the 3/4 power of mass—nearly identical.

This doesn’t prove causation, but it suggests sunlight could be a universal regulator of metabolic activity across the biosphere, with mitochondria in all organisms tuned to respond to the same infrared wavelengths present in Earth’s solar photon field.

What Makes This Hypothesis Different

Earlier theories proposed infrared light works by activating a photoreceptor in cytochrome c oxidase (complex IV) or by reducing water viscosity around ATP synthase motors.

Seheult’s team doesn’t reject these mechanisms—but argues they’re incomplete.

The Marcus framework explains phenomena earlier models couldn’t: why some infrared wavelengths inhibit rather than enhance mitochondrial activity, why broadband light outperforms monochromatic sources, and why effects persist across vastly different organisms.

The paper is the first to integrate four separate literature streams:

• Mitochondrial electron transfer follows Marcus physics
• Red and near-infrared light alter mitochondrial function
• Water and protein structures affect electron transfer kinetics
• Infrared radiation changes molecular electron transfer rates

“The novelty lies in the mechanistic integration,” Seheult emphasizes, “not in any single component.”

What Comes Next

The hypothesis is testable. Future experiments could measure how different infrared wavelengths alter specific Marcus crossing configurations in isolated mitochondrial complexes, or track real-time changes in reorganization energy using advanced spectroscopy.

If validated, the implications extend far beyond biology. Urban planning, architecture, workplace design, and lighting standards may all need reconsideration.

Seheult introduces a new term: photometabolism—solar-driven, non-photosynthetic modulation of core metabolic processes.

It’s a concept that positions sunlight not as a passive environmental factor, but as an active participant in the biochemistry of life itself.

I believe that this hypothesis if true has major implications for the built environment and how we live and the type of light that we require to live, and I believe it’s one of the major reasons why we need to be treating our patients outside.

Sources

• Jeffery et al. (2025) – Longer wavelengths in sunlight penetrating human tissue
• Ma et al. (2018) – Infrared perturbation of charge separation and recombination
• Sanderson et al. (2018) – Inhibitory modulation of cytochrome c oxidase with near-infrared wavelengths
• Dai et al. (2026) – Infrared stimulation of mitochondrial metabolism in deep-sea yeast
• Hayashi et al. (2010) – Water-mediated electron transfer in iron-sulfur bridges
• Marcus and Sutin (1985) – Electron transfer reactions in chemistry

Light is able to go through the body. It is able to be absorbed and it is doing stuff in the body.

In one striking experiment, 850-nanometer light was shown passing through a human hand with measurable intensity on the other side. Infrared wavelengths between 750 and 1,000 nanometers can even penetrate clothing.

This discovery opens the door to a startling possibility: infrared photons from the sun may be reaching mitochondria deep inside the body and influencing their activity in real time.

The Sun’s Special Infrared Signature

Not all light sources are created equal. The sun emits a broad spectrum of infrared wavelengths, but one particular photon energy—0.754 electron volts—is especially abundant.

This peak occurs because of the sun’s photosphere, a layer rich in negatively charged hydrogen atoms called hydride ions. These ions absorb higher-energy photons and re-emit them at exactly 0.754 electron volts.

Seheult likens it to dollar bills falling from the sky. While visible light carries the most total energy (like $100 bills), infrared photons are the most numerous (like $1 bills).

The result? A unique atmospheric window that allows these photons to reach Earth’s surface in abundance—and potentially interact with living cells in ways artificial light cannot replicate.

Marcus Electron Transfer: The Physics Behind the Biology

To understand how infrared light affects mitochondria, Seheult’s team turned to Marcus electron transfer theory, pioneered by Nobel laureate Rudolph Marcus in the 1960s.

Electrons don’t jump spontaneously between molecules. They require surrounding proteins, water, and lipids to twist into precise configurations—a process that demands energy called “reorganization energy.”

When infrared light hits these structures, it causes them to vibrate. This shifts the probability that molecules will be in the right arrangement for electron transfer to occur.

• If the crossing point is already accessible: Infrared light can push molecules away from optimal configurations, slowing electron transfer
• If the crossing point requires activation: Infrared light can push molecules toward optimal configurations, speeding electron transfer

This explains a puzzling finding from earlier studies: different infrared wavelengths can either increase or decrease mitochondrial activity.

Experiments Confirm the Mechanism

A 2018 study by Ma and colleagues tested this exact principle. Researchers built a custom molecule and used mid-infrared light to excite vibrational modes.

They found infrared light slowed forward electron transfer but accelerated backward transfer—precisely what Marcus theory predicts when nuclear orientations are shifted along energy curves.

IR excitation increases the probability of donor and acceptor energies to remain in degeneracy, resulting in IR-induced electron transfer rate enhancement.

Seheult notes he and co-author Dr. Robert Fosbury spoke with Marcus himself—just months before the scientist passed away at age 102—to discuss their hypothesis.

Deep-Sea Yeast Thrives on Infrared Light—Without Photosynthesis

Perhaps the most striking evidence comes from an unexpected source: yeast living near hydrothermal vents at the bottom of the ocean.

A 2026 study by Dai and colleagues isolated yeast from sediments near a “black smoker” chimney in the central Indian Ocean, more than half a meter from superheated mineral plumes reaching 378°C.

When researchers exposed these yeast cultures to near-infrared light (810–1050 nm) in temperature-controlled conditions, growth increased dramatically compared to dark controls—even though the yeast cannot photosynthesize.

Infrared light outperformed glucose. Adding glucose increased biomass by only 1.3-fold (not statistically significant), while 880-nanometer infrared light produced a threefold increase.

When researchers blocked cytochrome c oxidase (complex IV in mitochondria), near-infrared-stimulated growth dropped by 44%—suggesting the effect operates directly on mitochondrial machinery.

Cold Temperatures, Warm Light

Even more remarkable: infrared light allowed yeast to grow at cooler temperatures where dark controls remained dormant.

At 20°C, yeast exposed to 880-nanometer light grew vigorously while dark controls showed minimal activity. The effective activation energy dropped from 12 kilocalories per mole to just 2 kilocalories per mole.

Infrared light was making up for the cold temperatures by supplying vibrational activation rather than thermal activation.

Proteomics revealed the most upregulated protein after infrared exposure was a mitochondrial ribosomal protein (MRPs8), increased 6.7-fold.

Why Broadband Sunlight May Beat Monochromatic LEDs

Clinical studies using single-wavelength infrared devices have shown benefits—from reducing ICU length of stay to improving muscle strength in COVID-19 patients.

But Seheult’s hypothesis suggests broadband infrared from the sun may be even more effective.

“Sunlight contains a broad spectrum of wavelengths that can interact with many different vibrational modes and electron transfer steps,” he explains, “rather than targeting only one narrow pathway.”

Research from Jeffery’s lab supports this. When comparing monochromatic 850-nanometer light to a 60-watt incandescent bulb (which emits broad-spectrum infrared), the incandescent bulb produced greater improvements in color blindness.

• Monochromatic 850 nm: 9% improvement (head and body), 5% (body only)
• 60W incandescent bulb: 28% improvement, sustained for weeks

The research here aligns with the hypothesis, though direct mechanistic proof in human mitochondria remains to be demonstrated.

The Modern Indoor Environment: A Metabolic Desert?

LED bulbs emit virtually no infrared radiation. Low-emissivity (Low-E) glass windows, designed to improve energy efficiency, block infrared wavelengths.

Seheult measured infrared exposure in his own dining room with windows open: 0.8 watts per square meter.

Step outside under a shade tree with grass reflecting sunlight? 41.9 watts per square meter—more than 50 times higher.

We have set up a situation where outdoors we’re getting plenty of infrared light, versus being indoors where we have Low-E glass blocking it and LED bulbs producing none.

This raises profound questions about whether chronic infrared deficiency could contribute to the rising burden of metabolic diseases, especially among populations spending most of their time indoors.

Seasonal Mortality Patterns Point to Sunlight’s Role

Death rates from heart disease, cancer, stroke, Alzheimer’s, diabetes, and respiratory illness all peak one to three weeks after the shortest day of the year and bottom out after the longest day.

This pattern holds across both infectious and non-infectious causes. The seasonal variation in heart disease deaths alone exceeds total influenza deaths during flu season.

Australia shows the same pattern, but shifted six months—deaths peak in July, their winter. Singapore, 80 miles from the equator with year-round sun, shows no seasonal mortality pattern.

Multiple studies have linked mortality rates to latitude, independent of vitamin D levels, suggesting sunlight itself—particularly its infrared component—plays a direct metabolic role.

Hospitals Are Bringing Patients Outside

Armed with mounting evidence, hospitals worldwide are redesigning care spaces to maximize sunlight exposure.

A $1.5 billion hospital in Footscray, Australia, built ICU beds with direct outdoor access. King’s College Hospital in London invested £2 million to transform its rooftop into a critical care garden where up to six ICU patients can receive treatment surrounded by greenery and natural light.

St. George’s Hospital in London followed suit, creating a neurointensive care rooftop unit. Queen Camilla visited the facility in 2026 to recognize the innovation.

Randomized controlled trials using infrared vests delivering roughly 20–30 watts per square meter (comparable to sitting under a tree) showed 30% reductions in ICU length of stay and improved muscle strength in critically ill COVID-19 patients.

Metabolic Scaling Matches Solar Power Scaling

One of the paper’s most intriguing observations: metabolic rate scales with body mass to the 3/4 power across species from flies to elephants.

Solar power intercepted by an organism also scales to the 3/4 power of mass—nearly identical.

This doesn’t prove causation, but it suggests sunlight could be a universal regulator of metabolic activity across the biosphere, with mitochondria in all organisms tuned to respond to the same infrared wavelengths present in Earth’s solar photon field.

What Makes This Hypothesis Different

Earlier theories proposed infrared light works by activating a photoreceptor in cytochrome c oxidase (complex IV) or by reducing water viscosity around ATP synthase motors.

Seheult’s team doesn’t reject these mechanisms—but argues they’re incomplete.

The Marcus framework explains phenomena earlier models couldn’t: why some infrared wavelengths inhibit rather than enhance mitochondrial activity, why broadband light outperforms monochromatic sources, and why effects persist across vastly different organisms.

The paper is the first to integrate four separate literature streams:

• Mitochondrial electron transfer follows Marcus physics
• Red and near-infrared light alter mitochondrial function
• Water and protein structures affect electron transfer kinetics
• Infrared radiation changes molecular electron transfer rates

“The novelty lies in the mechanistic integration,” Seheult emphasizes, “not in any single component.”

What Comes Next

The hypothesis is testable. Future experiments could measure how different infrared wavelengths alter specific Marcus crossing configurations in isolated mitochondrial complexes, or track real-time changes in reorganization energy using advanced spectroscopy.

If validated, the implications extend far beyond biology. Urban planning, architecture, workplace design, and lighting standards may all need reconsideration.

Seheult introduces a new term: photometabolism—solar-driven, non-photosynthetic modulation of core metabolic processes.

It’s a concept that positions sunlight not as a passive environmental factor, but as an active participant in the biochemistry of life itself.

I believe that this hypothesis if true has major implications for the built environment and how we live and the type of light that we require to live, and I believe it’s one of the major reasons why we need to be treating our patients outside.

Sources

• Jeffery et al. (2025) – Longer wavelengths in sunlight penetrating human tissue
• Ma et al. (2018) – Infrared perturbation of charge separation and recombination
• Sanderson et al. (2018) – Inhibitory modulation of cytochrome c oxidase with near-infrared wavelengths
• Dai et al. (2026) – Infrared stimulation of mitochondrial metabolism in deep-sea yeast
• Hayashi et al. (2010) – Water-mediated electron transfer in iron-sulfur bridges
• Marcus and Sutin (1985) – Electron transfer reactions in chemistry

Light is able to go through the body. It is able to be absorbed and it is doing stuff in the body.

In one striking experiment, 850-nanometer light was shown passing through a human hand with measurable intensity on the other side. Infrared wavelengths between 750 and 1,000 nanometers can even penetrate clothing.

This discovery opens the door to a startling possibility: infrared photons from the sun may be reaching mitochondria deep inside the body and influencing their activity in real time.

The Sun’s Special Infrared Signature

Not all light sources are created equal. The sun emits a broad spectrum of infrared wavelengths, but one particular photon energy—0.754 electron volts—is especially abundant.

This peak occurs because of the sun’s photosphere, a layer rich in negatively charged hydrogen atoms called hydride ions. These ions absorb higher-energy photons and re-emit them at exactly 0.754 electron volts.

Seheult likens it to dollar bills falling from the sky. While visible light carries the most total energy (like $100 bills), infrared photons are the most numerous (like $1 bills).

The result? A unique atmospheric window that allows these photons to reach Earth’s surface in abundance—and potentially interact with living cells in ways artificial light cannot replicate.

Marcus Electron Transfer: The Physics Behind the Biology

To understand how infrared light affects mitochondria, Seheult’s team turned to Marcus electron transfer theory, pioneered by Nobel laureate Rudolph Marcus in the 1960s.

Electrons don’t jump spontaneously between molecules. They require surrounding proteins, water, and lipids to twist into precise configurations—a process that demands energy called “reorganization energy.”

When infrared light hits these structures, it causes them to vibrate. This shifts the probability that molecules will be in the right arrangement for electron transfer to occur.

• If the crossing point is already accessible: Infrared light can push molecules away from optimal configurations, slowing electron transfer
• If the crossing point requires activation: Infrared light can push molecules toward optimal configurations, speeding electron transfer

This explains a puzzling finding from earlier studies: different infrared wavelengths can either increase or decrease mitochondrial activity.

Experiments Confirm the Mechanism

A 2018 study by Ma and colleagues tested this exact principle. Researchers built a custom molecule and used mid-infrared light to excite vibrational modes.

They found infrared light slowed forward electron transfer but accelerated backward transfer—precisely what Marcus theory predicts when nuclear orientations are shifted along energy curves.

IR excitation increases the probability of donor and acceptor energies to remain in degeneracy, resulting in IR-induced electron transfer rate enhancement.

Seheult notes he and co-author Dr. Robert Fosbury spoke with Marcus himself—just months before the scientist passed away at age 102—to discuss their hypothesis.

Deep-Sea Yeast Thrives on Infrared Light—Without Photosynthesis

Perhaps the most striking evidence comes from an unexpected source: yeast living near hydrothermal vents at the bottom of the ocean.

A 2026 study by Dai and colleagues isolated yeast from sediments near a “black smoker” chimney in the central Indian Ocean, more than half a meter from superheated mineral plumes reaching 378°C.

When researchers exposed these yeast cultures to near-infrared light (810–1050 nm) in temperature-controlled conditions, growth increased dramatically compared to dark controls—even though the yeast cannot photosynthesize.

Infrared light outperformed glucose. Adding glucose increased biomass by only 1.3-fold (not statistically significant), while 880-nanometer infrared light produced a threefold increase.

When researchers blocked cytochrome c oxidase (complex IV in mitochondria), near-infrared-stimulated growth dropped by 44%—suggesting the effect operates directly on mitochondrial machinery.

Cold Temperatures, Warm Light

Even more remarkable: infrared light allowed yeast to grow at cooler temperatures where dark controls remained dormant.

At 20°C, yeast exposed to 880-nanometer light grew vigorously while dark controls showed minimal activity. The effective activation energy dropped from 12 kilocalories per mole to just 2 kilocalories per mole.

Infrared light was making up for the cold temperatures by supplying vibrational activation rather than thermal activation.

Proteomics revealed the most upregulated protein after infrared exposure was a mitochondrial ribosomal protein (MRPs8), increased 6.7-fold.

Why Broadband Sunlight May Beat Monochromatic LEDs

Clinical studies using single-wavelength infrared devices have shown benefits—from reducing ICU length of stay to improving muscle strength in COVID-19 patients.

But Seheult’s hypothesis suggests broadband infrared from the sun may be even more effective.

“Sunlight contains a broad spectrum of wavelengths that can interact with many different vibrational modes and electron transfer steps,” he explains, “rather than targeting only one narrow pathway.”

Research from Jeffery’s lab supports this. When comparing monochromatic 850-nanometer light to a 60-watt incandescent bulb (which emits broad-spectrum infrared), the incandescent bulb produced greater improvements in color blindness.

• Monochromatic 850 nm: 9% improvement (head and body), 5% (body only)
• 60W incandescent bulb: 28% improvement, sustained for weeks

The research here aligns with the hypothesis, though direct mechanistic proof in human mitochondria remains to be demonstrated.

The Modern Indoor Environment: A Metabolic Desert?

LED bulbs emit virtually no infrared radiation. Low-emissivity (Low-E) glass windows, designed to improve energy efficiency, block infrared wavelengths.

Seheult measured infrared exposure in his own dining room with windows open: 0.8 watts per square meter.

Step outside under a shade tree with grass reflecting sunlight? 41.9 watts per square meter—more than 50 times higher.

We have set up a situation where outdoors we’re getting plenty of infrared light, versus being indoors where we have Low-E glass blocking it and LED bulbs producing none.

This raises profound questions about whether chronic infrared deficiency could contribute to the rising burden of metabolic diseases, especially among populations spending most of their time indoors.

Seasonal Mortality Patterns Point to Sunlight’s Role

Death rates from heart disease, cancer, stroke, Alzheimer’s, diabetes, and respiratory illness all peak one to three weeks after the shortest day of the year and bottom out after the longest day.

This pattern holds across both infectious and non-infectious causes. The seasonal variation in heart disease deaths alone exceeds total influenza deaths during flu season.

Australia shows the same pattern, but shifted six months—deaths peak in July, their winter. Singapore, 80 miles from the equator with year-round sun, shows no seasonal mortality pattern.

Multiple studies have linked mortality rates to latitude, independent of vitamin D levels, suggesting sunlight itself—particularly its infrared component—plays a direct metabolic role.

Hospitals Are Bringing Patients Outside

Armed with mounting evidence, hospitals worldwide are redesigning care spaces to maximize sunlight exposure.

A $1.5 billion hospital in Footscray, Australia, built ICU beds with direct outdoor access. King’s College Hospital in London invested £2 million to transform its rooftop into a critical care garden where up to six ICU patients can receive treatment surrounded by greenery and natural light.

St. George’s Hospital in London followed suit, creating a neurointensive care rooftop unit. Queen Camilla visited the facility in 2026 to recognize the innovation.

Randomized controlled trials using infrared vests delivering roughly 20–30 watts per square meter (comparable to sitting under a tree) showed 30% reductions in ICU length of stay and improved muscle strength in critically ill COVID-19 patients.

Metabolic Scaling Matches Solar Power Scaling

One of the paper’s most intriguing observations: metabolic rate scales with body mass to the 3/4 power across species from flies to elephants.

Solar power intercepted by an organism also scales to the 3/4 power of mass—nearly identical.

This doesn’t prove causation, but it suggests sunlight could be a universal regulator of metabolic activity across the biosphere, with mitochondria in all organisms tuned to respond to the same infrared wavelengths present in Earth’s solar photon field.

What Makes This Hypothesis Different

Earlier theories proposed infrared light works by activating a photoreceptor in cytochrome c oxidase (complex IV) or by reducing water viscosity around ATP synthase motors.

Seheult’s team doesn’t reject these mechanisms—but argues they’re incomplete.

The Marcus framework explains phenomena earlier models couldn’t: why some infrared wavelengths inhibit rather than enhance mitochondrial activity, why broadband light outperforms monochromatic sources, and why effects persist across vastly different organisms.

The paper is the first to integrate four separate literature streams:

• Mitochondrial electron transfer follows Marcus physics
• Red and near-infrared light alter mitochondrial function
• Water and protein structures affect electron transfer kinetics
• Infrared radiation changes molecular electron transfer rates

“The novelty lies in the mechanistic integration,” Seheult emphasizes, “not in any single component.”

What Comes Next

The hypothesis is testable. Future experiments could measure how different infrared wavelengths alter specific Marcus crossing configurations in isolated mitochondrial complexes, or track real-time changes in reorganization energy using advanced spectroscopy.

If validated, the implications extend far beyond biology. Urban planning, architecture, workplace design, and lighting standards may all need reconsideration.

Seheult introduces a new term: photometabolism—solar-driven, non-photosynthetic modulation of core metabolic processes.

It’s a concept that positions sunlight not as a passive environmental factor, but as an active participant in the biochemistry of life itself.

I believe that this hypothesis if true has major implications for the built environment and how we live and the type of light that we require to live, and I believe it’s one of the major reasons why we need to be treating our patients outside.

Sources

• Jeffery et al. (2025) – Longer wavelengths in sunlight penetrating human tissue
• Ma et al. (2018) – Infrared perturbation of charge separation and recombination
• Sanderson et al. (2018) – Inhibitory modulation of cytochrome c oxidase with near-infrared wavelengths
• Dai et al. (2026) – Infrared stimulation of mitochondrial metabolism in deep-sea yeast
• Hayashi et al. (2010) – Water-mediated electron transfer in iron-sulfur bridges
• Marcus and Sutin (1985) – Electron transfer reactions in chemistry

Most people assume sunlight only affects the skin surface. But research published in 2025 by Dr. Glenn Jeffery’s group demonstrated that longer wavelengths of infrared light can pass completely through human tissue.

Light is able to go through the body. It is able to be absorbed and it is doing stuff in the body.

In one striking experiment, 850-nanometer light was shown passing through a human hand with measurable intensity on the other side. Infrared wavelengths between 750 and 1,000 nanometers can even penetrate clothing.

This discovery opens the door to a startling possibility: infrared photons from the sun may be reaching mitochondria deep inside the body and influencing their activity in real time.

The Sun’s Special Infrared Signature

Not all light sources are created equal. The sun emits a broad spectrum of infrared wavelengths, but one particular photon energy—0.754 electron volts—is especially abundant.

This peak occurs because of the sun’s photosphere, a layer rich in negatively charged hydrogen atoms called hydride ions. These ions absorb higher-energy photons and re-emit them at exactly 0.754 electron volts.

Seheult likens it to dollar bills falling from the sky. While visible light carries the most total energy (like $100 bills), infrared photons are the most numerous (like $1 bills).

The result? A unique atmospheric window that allows these photons to reach Earth’s surface in abundance—and potentially interact with living cells in ways artificial light cannot replicate.

Marcus Electron Transfer: The Physics Behind the Biology

To understand how infrared light affects mitochondria, Seheult’s team turned to Marcus electron transfer theory, pioneered by Nobel laureate Rudolph Marcus in the 1960s.

Electrons don’t jump spontaneously between molecules. They require surrounding proteins, water, and lipids to twist into precise configurations—a process that demands energy called “reorganization energy.”

When infrared light hits these structures, it causes them to vibrate. This shifts the probability that molecules will be in the right arrangement for electron transfer to occur.

• If the crossing point is already accessible: Infrared light can push molecules away from optimal configurations, slowing electron transfer
• If the crossing point requires activation: Infrared light can push molecules toward optimal configurations, speeding electron transfer

This explains a puzzling finding from earlier studies: different infrared wavelengths can either increase or decrease mitochondrial activity.

Experiments Confirm the Mechanism

A 2018 study by Ma and colleagues tested this exact principle. Researchers built a custom molecule and used mid-infrared light to excite vibrational modes.

They found infrared light slowed forward electron transfer but accelerated backward transfer—precisely what Marcus theory predicts when nuclear orientations are shifted along energy curves.

IR excitation increases the probability of donor and acceptor energies to remain in degeneracy, resulting in IR-induced electron transfer rate enhancement.

Seheult notes he and co-author Dr. Robert Fosbury spoke with Marcus himself—just months before the scientist passed away at age 102—to discuss their hypothesis.

Deep-Sea Yeast Thrives on Infrared Light—Without Photosynthesis

Perhaps the most striking evidence comes from an unexpected source: yeast living near hydrothermal vents at the bottom of the ocean.

A 2026 study by Dai and colleagues isolated yeast from sediments near a “black smoker” chimney in the central Indian Ocean, more than half a meter from superheated mineral plumes reaching 378°C.

When researchers exposed these yeast cultures to near-infrared light (810–1050 nm) in temperature-controlled conditions, growth increased dramatically compared to dark controls—even though the yeast cannot photosynthesize.

Infrared light outperformed glucose. Adding glucose increased biomass by only 1.3-fold (not statistically significant), while 880-nanometer infrared light produced a threefold increase.

When researchers blocked cytochrome c oxidase (complex IV in mitochondria), near-infrared-stimulated growth dropped by 44%—suggesting the effect operates directly on mitochondrial machinery.

Cold Temperatures, Warm Light

Even more remarkable: infrared light allowed yeast to grow at cooler temperatures where dark controls remained dormant.

At 20°C, yeast exposed to 880-nanometer light grew vigorously while dark controls showed minimal activity. The effective activation energy dropped from 12 kilocalories per mole to just 2 kilocalories per mole.

Infrared light was making up for the cold temperatures by supplying vibrational activation rather than thermal activation.

Proteomics revealed the most upregulated protein after infrared exposure was a mitochondrial ribosomal protein (MRPs8), increased 6.7-fold.

Why Broadband Sunlight May Beat Monochromatic LEDs

Clinical studies using single-wavelength infrared devices have shown benefits—from reducing ICU length of stay to improving muscle strength in COVID-19 patients.

But Seheult’s hypothesis suggests broadband infrared from the sun may be even more effective.

“Sunlight contains a broad spectrum of wavelengths that can interact with many different vibrational modes and electron transfer steps,” he explains, “rather than targeting only one narrow pathway.”

Research from Jeffery’s lab supports this. When comparing monochromatic 850-nanometer light to a 60-watt incandescent bulb (which emits broad-spectrum infrared), the incandescent bulb produced greater improvements in color blindness.

• Monochromatic 850 nm: 9% improvement (head and body), 5% (body only)
• 60W incandescent bulb: 28% improvement, sustained for weeks

The research here aligns with the hypothesis, though direct mechanistic proof in human mitochondria remains to be demonstrated.

The Modern Indoor Environment: A Metabolic Desert?

LED bulbs emit virtually no infrared radiation. Low-emissivity (Low-E) glass windows, designed to improve energy efficiency, block infrared wavelengths.

Seheult measured infrared exposure in his own dining room with windows open: 0.8 watts per square meter.

Step outside under a shade tree with grass reflecting sunlight? 41.9 watts per square meter—more than 50 times higher.

We have set up a situation where outdoors we’re getting plenty of infrared light, versus being indoors where we have Low-E glass blocking it and LED bulbs producing none.

This raises profound questions about whether chronic infrared deficiency could contribute to the rising burden of metabolic diseases, especially among populations spending most of their time indoors.

Seasonal Mortality Patterns Point to Sunlight’s Role

Death rates from heart disease, cancer, stroke, Alzheimer’s, diabetes, and respiratory illness all peak one to three weeks after the shortest day of the year and bottom out after the longest day.

This pattern holds across both infectious and non-infectious causes. The seasonal variation in heart disease deaths alone exceeds total influenza deaths during flu season.

Australia shows the same pattern, but shifted six months—deaths peak in July, their winter. Singapore, 80 miles from the equator with year-round sun, shows no seasonal mortality pattern.

Multiple studies have linked mortality rates to latitude, independent of vitamin D levels, suggesting sunlight itself—particularly its infrared component—plays a direct metabolic role.

Hospitals Are Bringing Patients Outside

Armed with mounting evidence, hospitals worldwide are redesigning care spaces to maximize sunlight exposure.

A $1.5 billion hospital in Footscray, Australia, built ICU beds with direct outdoor access. King’s College Hospital in London invested £2 million to transform its rooftop into a critical care garden where up to six ICU patients can receive treatment surrounded by greenery and natural light.

St. George’s Hospital in London followed suit, creating a neurointensive care rooftop unit. Queen Camilla visited the facility in 2026 to recognize the innovation.

Randomized controlled trials using infrared vests delivering roughly 20–30 watts per square meter (comparable to sitting under a tree) showed 30% reductions in ICU length of stay and improved muscle strength in critically ill COVID-19 patients.

Metabolic Scaling Matches Solar Power Scaling

One of the paper’s most intriguing observations: metabolic rate scales with body mass to the 3/4 power across species from flies to elephants.

Solar power intercepted by an organism also scales to the 3/4 power of mass—nearly identical.

This doesn’t prove causation, but it suggests sunlight could be a universal regulator of metabolic activity across the biosphere, with mitochondria in all organisms tuned to respond to the same infrared wavelengths present in Earth’s solar photon field.

What Makes This Hypothesis Different

Earlier theories proposed infrared light works by activating a photoreceptor in cytochrome c oxidase (complex IV) or by reducing water viscosity around ATP synthase motors.

Seheult’s team doesn’t reject these mechanisms—but argues they’re incomplete.

The Marcus framework explains phenomena earlier models couldn’t: why some infrared wavelengths inhibit rather than enhance mitochondrial activity, why broadband light outperforms monochromatic sources, and why effects persist across vastly different organisms.

The paper is the first to integrate four separate literature streams:

• Mitochondrial electron transfer follows Marcus physics
• Red and near-infrared light alter mitochondrial function
• Water and protein structures affect electron transfer kinetics
• Infrared radiation changes molecular electron transfer rates

“The novelty lies in the mechanistic integration,” Seheult emphasizes, “not in any single component.”

What Comes Next

The hypothesis is testable. Future experiments could measure how different infrared wavelengths alter specific Marcus crossing configurations in isolated mitochondrial complexes, or track real-time changes in reorganization energy using advanced spectroscopy.

If validated, the implications extend far beyond biology. Urban planning, architecture, workplace design, and lighting standards may all need reconsideration.

Seheult introduces a new term: photometabolism—solar-driven, non-photosynthetic modulation of core metabolic processes.

It’s a concept that positions sunlight not as a passive environmental factor, but as an active participant in the biochemistry of life itself.

I believe that this hypothesis if true has major implications for the built environment and how we live and the type of light that we require to live, and I believe it’s one of the major reasons why we need to be treating our patients outside.

Sources

• Jeffery et al. (2025) – Longer wavelengths in sunlight penetrating human tissue
• Ma et al. (2018) – Infrared perturbation of charge separation and recombination
• Sanderson et al. (2018) – Inhibitory modulation of cytochrome c oxidase with near-infrared wavelengths
• Dai et al. (2026) – Infrared stimulation of mitochondrial metabolism in deep-sea yeast
• Hayashi et al. (2010) – Water-mediated electron transfer in iron-sulfur bridges
• Marcus and Sutin (1985) – Electron transfer reactions in chemistry

Most people assume sunlight only affects the skin surface. But research published in 2025 by Dr. Glenn Jeffery’s group demonstrated that longer wavelengths of infrared light can pass completely through human tissue.

Light is able to go through the body. It is able to be absorbed and it is doing stuff in the body.

In one striking experiment, 850-nanometer light was shown passing through a human hand with measurable intensity on the other side. Infrared wavelengths between 750 and 1,000 nanometers can even penetrate clothing.

This discovery opens the door to a startling possibility: infrared photons from the sun may be reaching mitochondria deep inside the body and influencing their activity in real time.

The Sun’s Special Infrared Signature

Not all light sources are created equal. The sun emits a broad spectrum of infrared wavelengths, but one particular photon energy—0.754 electron volts—is especially abundant.

This peak occurs because of the sun’s photosphere, a layer rich in negatively charged hydrogen atoms called hydride ions. These ions absorb higher-energy photons and re-emit them at exactly 0.754 electron volts.

Seheult likens it to dollar bills falling from the sky. While visible light carries the most total energy (like $100 bills), infrared photons are the most numerous (like $1 bills).

The result? A unique atmospheric window that allows these photons to reach Earth’s surface in abundance—and potentially interact with living cells in ways artificial light cannot replicate.

Marcus Electron Transfer: The Physics Behind the Biology

To understand how infrared light affects mitochondria, Seheult’s team turned to Marcus electron transfer theory, pioneered by Nobel laureate Rudolph Marcus in the 1960s.

Electrons don’t jump spontaneously between molecules. They require surrounding proteins, water, and lipids to twist into precise configurations—a process that demands energy called “reorganization energy.”

When infrared light hits these structures, it causes them to vibrate. This shifts the probability that molecules will be in the right arrangement for electron transfer to occur.

• If the crossing point is already accessible: Infrared light can push molecules away from optimal configurations, slowing electron transfer
• If the crossing point requires activation: Infrared light can push molecules toward optimal configurations, speeding electron transfer

This explains a puzzling finding from earlier studies: different infrared wavelengths can either increase or decrease mitochondrial activity.

Experiments Confirm the Mechanism

A 2018 study by Ma and colleagues tested this exact principle. Researchers built a custom molecule and used mid-infrared light to excite vibrational modes.

They found infrared light slowed forward electron transfer but accelerated backward transfer—precisely what Marcus theory predicts when nuclear orientations are shifted along energy curves.

IR excitation increases the probability of donor and acceptor energies to remain in degeneracy, resulting in IR-induced electron transfer rate enhancement.

Seheult notes he and co-author Dr. Robert Fosbury spoke with Marcus himself—just months before the scientist passed away at age 102—to discuss their hypothesis.

Deep-Sea Yeast Thrives on Infrared Light—Without Photosynthesis

Perhaps the most striking evidence comes from an unexpected source: yeast living near hydrothermal vents at the bottom of the ocean.

A 2026 study by Dai and colleagues isolated yeast from sediments near a “black smoker” chimney in the central Indian Ocean, more than half a meter from superheated mineral plumes reaching 378°C.

When researchers exposed these yeast cultures to near-infrared light (810–1050 nm) in temperature-controlled conditions, growth increased dramatically compared to dark controls—even though the yeast cannot photosynthesize.

Infrared light outperformed glucose. Adding glucose increased biomass by only 1.3-fold (not statistically significant), while 880-nanometer infrared light produced a threefold increase.

When researchers blocked cytochrome c oxidase (complex IV in mitochondria), near-infrared-stimulated growth dropped by 44%—suggesting the effect operates directly on mitochondrial machinery.

Cold Temperatures, Warm Light

Even more remarkable: infrared light allowed yeast to grow at cooler temperatures where dark controls remained dormant.

At 20°C, yeast exposed to 880-nanometer light grew vigorously while dark controls showed minimal activity. The effective activation energy dropped from 12 kilocalories per mole to just 2 kilocalories per mole.

Infrared light was making up for the cold temperatures by supplying vibrational activation rather than thermal activation.

Proteomics revealed the most upregulated protein after infrared exposure was a mitochondrial ribosomal protein (MRPs8), increased 6.7-fold.

Why Broadband Sunlight May Beat Monochromatic LEDs

Clinical studies using single-wavelength infrared devices have shown benefits—from reducing ICU length of stay to improving muscle strength in COVID-19 patients.

But Seheult’s hypothesis suggests broadband infrared from the sun may be even more effective.

“Sunlight contains a broad spectrum of wavelengths that can interact with many different vibrational modes and electron transfer steps,” he explains, “rather than targeting only one narrow pathway.”

Research from Jeffery’s lab supports this. When comparing monochromatic 850-nanometer light to a 60-watt incandescent bulb (which emits broad-spectrum infrared), the incandescent bulb produced greater improvements in color blindness.

• Monochromatic 850 nm: 9% improvement (head and body), 5% (body only)
• 60W incandescent bulb: 28% improvement, sustained for weeks

The research here aligns with the hypothesis, though direct mechanistic proof in human mitochondria remains to be demonstrated.

The Modern Indoor Environment: A Metabolic Desert?

LED bulbs emit virtually no infrared radiation. Low-emissivity (Low-E) glass windows, designed to improve energy efficiency, block infrared wavelengths.

Seheult measured infrared exposure in his own dining room with windows open: 0.8 watts per square meter.

Step outside under a shade tree with grass reflecting sunlight? 41.9 watts per square meter—more than 50 times higher.

We have set up a situation where outdoors we’re getting plenty of infrared light, versus being indoors where we have Low-E glass blocking it and LED bulbs producing none.

This raises profound questions about whether chronic infrared deficiency could contribute to the rising burden of metabolic diseases, especially among populations spending most of their time indoors.

Seasonal Mortality Patterns Point to Sunlight’s Role

Death rates from heart disease, cancer, stroke, Alzheimer’s, diabetes, and respiratory illness all peak one to three weeks after the shortest day of the year and bottom out after the longest day.

This pattern holds across both infectious and non-infectious causes. The seasonal variation in heart disease deaths alone exceeds total influenza deaths during flu season.

Australia shows the same pattern, but shifted six months—deaths peak in July, their winter. Singapore, 80 miles from the equator with year-round sun, shows no seasonal mortality pattern.

Multiple studies have linked mortality rates to latitude, independent of vitamin D levels, suggesting sunlight itself—particularly its infrared component—plays a direct metabolic role.

Hospitals Are Bringing Patients Outside

Armed with mounting evidence, hospitals worldwide are redesigning care spaces to maximize sunlight exposure.

A $1.5 billion hospital in Footscray, Australia, built ICU beds with direct outdoor access. King’s College Hospital in London invested £2 million to transform its rooftop into a critical care garden where up to six ICU patients can receive treatment surrounded by greenery and natural light.

St. George’s Hospital in London followed suit, creating a neurointensive care rooftop unit. Queen Camilla visited the facility in 2026 to recognize the innovation.

Randomized controlled trials using infrared vests delivering roughly 20–30 watts per square meter (comparable to sitting under a tree) showed 30% reductions in ICU length of stay and improved muscle strength in critically ill COVID-19 patients.

Metabolic Scaling Matches Solar Power Scaling

One of the paper’s most intriguing observations: metabolic rate scales with body mass to the 3/4 power across species from flies to elephants.

Solar power intercepted by an organism also scales to the 3/4 power of mass—nearly identical.

This doesn’t prove causation, but it suggests sunlight could be a universal regulator of metabolic activity across the biosphere, with mitochondria in all organisms tuned to respond to the same infrared wavelengths present in Earth’s solar photon field.

What Makes This Hypothesis Different

Earlier theories proposed infrared light works by activating a photoreceptor in cytochrome c oxidase (complex IV) or by reducing water viscosity around ATP synthase motors.

Seheult’s team doesn’t reject these mechanisms—but argues they’re incomplete.

The Marcus framework explains phenomena earlier models couldn’t: why some infrared wavelengths inhibit rather than enhance mitochondrial activity, why broadband light outperforms monochromatic sources, and why effects persist across vastly different organisms.

The paper is the first to integrate four separate literature streams:

• Mitochondrial electron transfer follows Marcus physics
• Red and near-infrared light alter mitochondrial function
• Water and protein structures affect electron transfer kinetics
• Infrared radiation changes molecular electron transfer rates

“The novelty lies in the mechanistic integration,” Seheult emphasizes, “not in any single component.”

What Comes Next

The hypothesis is testable. Future experiments could measure how different infrared wavelengths alter specific Marcus crossing configurations in isolated mitochondrial complexes, or track real-time changes in reorganization energy using advanced spectroscopy.

If validated, the implications extend far beyond biology. Urban planning, architecture, workplace design, and lighting standards may all need reconsideration.

Seheult introduces a new term: photometabolism—solar-driven, non-photosynthetic modulation of core metabolic processes.

It’s a concept that positions sunlight not as a passive environmental factor, but as an active participant in the biochemistry of life itself.

I believe that this hypothesis if true has major implications for the built environment and how we live and the type of light that we require to live, and I believe it’s one of the major reasons why we need to be treating our patients outside.

Sources

• Jeffery et al. (2025) – Longer wavelengths in sunlight penetrating human tissue
• Ma et al. (2018) – Infrared perturbation of charge separation and recombination
• Sanderson et al. (2018) – Inhibitory modulation of cytochrome c oxidase with near-infrared wavelengths
• Dai et al. (2026) – Infrared stimulation of mitochondrial metabolism in deep-sea yeast
• Hayashi et al. (2010) – Water-mediated electron transfer in iron-sulfur bridges
• Marcus and Sutin (1985) – Electron transfer reactions in chemistry

Why Sunlight Penetrates Deeper Than You Think

Most people assume sunlight only affects the skin surface. But research published in 2025 by Dr. Glenn Jeffery’s group demonstrated that longer wavelengths of infrared light can pass completely through human tissue.

Light is able to go through the body. It is able to be absorbed and it is doing stuff in the body.

In one striking experiment, 850-nanometer light was shown passing through a human hand with measurable intensity on the other side. Infrared wavelengths between 750 and 1,000 nanometers can even penetrate clothing.

This discovery opens the door to a startling possibility: infrared photons from the sun may be reaching mitochondria deep inside the body and influencing their activity in real time.

The Sun’s Special Infrared Signature

Not all light sources are created equal. The sun emits a broad spectrum of infrared wavelengths, but one particular photon energy—0.754 electron volts—is especially abundant.

This peak occurs because of the sun’s photosphere, a layer rich in negatively charged hydrogen atoms called hydride ions. These ions absorb higher-energy photons and re-emit them at exactly 0.754 electron volts.

Seheult likens it to dollar bills falling from the sky. While visible light carries the most total energy (like $100 bills), infrared photons are the most numerous (like $1 bills).

The result? A unique atmospheric window that allows these photons to reach Earth’s surface in abundance—and potentially interact with living cells in ways artificial light cannot replicate.

Marcus Electron Transfer: The Physics Behind the Biology

To understand how infrared light affects mitochondria, Seheult’s team turned to Marcus electron transfer theory, pioneered by Nobel laureate Rudolph Marcus in the 1960s.

Electrons don’t jump spontaneously between molecules. They require surrounding proteins, water, and lipids to twist into precise configurations—a process that demands energy called “reorganization energy.”

When infrared light hits these structures, it causes them to vibrate. This shifts the probability that molecules will be in the right arrangement for electron transfer to occur.

• If the crossing point is already accessible: Infrared light can push molecules away from optimal configurations, slowing electron transfer
• If the crossing point requires activation: Infrared light can push molecules toward optimal configurations, speeding electron transfer

This explains a puzzling finding from earlier studies: different infrared wavelengths can either increase or decrease mitochondrial activity.

Experiments Confirm the Mechanism

A 2018 study by Ma and colleagues tested this exact principle. Researchers built a custom molecule and used mid-infrared light to excite vibrational modes.

They found infrared light slowed forward electron transfer but accelerated backward transfer—precisely what Marcus theory predicts when nuclear orientations are shifted along energy curves.

IR excitation increases the probability of donor and acceptor energies to remain in degeneracy, resulting in IR-induced electron transfer rate enhancement.

Seheult notes he and co-author Dr. Robert Fosbury spoke with Marcus himself—just months before the scientist passed away at age 102—to discuss their hypothesis.

Deep-Sea Yeast Thrives on Infrared Light—Without Photosynthesis

Perhaps the most striking evidence comes from an unexpected source: yeast living near hydrothermal vents at the bottom of the ocean.

A 2026 study by Dai and colleagues isolated yeast from sediments near a “black smoker” chimney in the central Indian Ocean, more than half a meter from superheated mineral plumes reaching 378°C.

When researchers exposed these yeast cultures to near-infrared light (810–1050 nm) in temperature-controlled conditions, growth increased dramatically compared to dark controls—even though the yeast cannot photosynthesize.

Infrared light outperformed glucose. Adding glucose increased biomass by only 1.3-fold (not statistically significant), while 880-nanometer infrared light produced a threefold increase.

When researchers blocked cytochrome c oxidase (complex IV in mitochondria), near-infrared-stimulated growth dropped by 44%—suggesting the effect operates directly on mitochondrial machinery.

Cold Temperatures, Warm Light

Even more remarkable: infrared light allowed yeast to grow at cooler temperatures where dark controls remained dormant.

At 20°C, yeast exposed to 880-nanometer light grew vigorously while dark controls showed minimal activity. The effective activation energy dropped from 12 kilocalories per mole to just 2 kilocalories per mole.

Infrared light was making up for the cold temperatures by supplying vibrational activation rather than thermal activation.

Proteomics revealed the most upregulated protein after infrared exposure was a mitochondrial ribosomal protein (MRPs8), increased 6.7-fold.

Why Broadband Sunlight May Beat Monochromatic LEDs

Clinical studies using single-wavelength infrared devices have shown benefits—from reducing ICU length of stay to improving muscle strength in COVID-19 patients.

But Seheult’s hypothesis suggests broadband infrared from the sun may be even more effective.

“Sunlight contains a broad spectrum of wavelengths that can interact with many different vibrational modes and electron transfer steps,” he explains, “rather than targeting only one narrow pathway.”

Research from Jeffery’s lab supports this. When comparing monochromatic 850-nanometer light to a 60-watt incandescent bulb (which emits broad-spectrum infrared), the incandescent bulb produced greater improvements in color blindness.

• Monochromatic 850 nm: 9% improvement (head and body), 5% (body only)
• 60W incandescent bulb: 28% improvement, sustained for weeks

The research here aligns with the hypothesis, though direct mechanistic proof in human mitochondria remains to be demonstrated.

The Modern Indoor Environment: A Metabolic Desert?

LED bulbs emit virtually no infrared radiation. Low-emissivity (Low-E) glass windows, designed to improve energy efficiency, block infrared wavelengths.

Seheult measured infrared exposure in his own dining room with windows open: 0.8 watts per square meter.

Step outside under a shade tree with grass reflecting sunlight? 41.9 watts per square meter—more than 50 times higher.

We have set up a situation where outdoors we’re getting plenty of infrared light, versus being indoors where we have Low-E glass blocking it and LED bulbs producing none.

This raises profound questions about whether chronic infrared deficiency could contribute to the rising burden of metabolic diseases, especially among populations spending most of their time indoors.

Seasonal Mortality Patterns Point to Sunlight’s Role

Death rates from heart disease, cancer, stroke, Alzheimer’s, diabetes, and respiratory illness all peak one to three weeks after the shortest day of the year and bottom out after the longest day.

This pattern holds across both infectious and non-infectious causes. The seasonal variation in heart disease deaths alone exceeds total influenza deaths during flu season.

Australia shows the same pattern, but shifted six months—deaths peak in July, their winter. Singapore, 80 miles from the equator with year-round sun, shows no seasonal mortality pattern.

Multiple studies have linked mortality rates to latitude, independent of vitamin D levels, suggesting sunlight itself—particularly its infrared component—plays a direct metabolic role.

Hospitals Are Bringing Patients Outside

Armed with mounting evidence, hospitals worldwide are redesigning care spaces to maximize sunlight exposure.

A $1.5 billion hospital in Footscray, Australia, built ICU beds with direct outdoor access. King’s College Hospital in London invested £2 million to transform its rooftop into a critical care garden where up to six ICU patients can receive treatment surrounded by greenery and natural light.

St. George’s Hospital in London followed suit, creating a neurointensive care rooftop unit. Queen Camilla visited the facility in 2026 to recognize the innovation.

Randomized controlled trials using infrared vests delivering roughly 20–30 watts per square meter (comparable to sitting under a tree) showed 30% reductions in ICU length of stay and improved muscle strength in critically ill COVID-19 patients.

Metabolic Scaling Matches Solar Power Scaling

One of the paper’s most intriguing observations: metabolic rate scales with body mass to the 3/4 power across species from flies to elephants.

Solar power intercepted by an organism also scales to the 3/4 power of mass—nearly identical.

This doesn’t prove causation, but it suggests sunlight could be a universal regulator of metabolic activity across the biosphere, with mitochondria in all organisms tuned to respond to the same infrared wavelengths present in Earth’s solar photon field.

What Makes This Hypothesis Different

Earlier theories proposed infrared light works by activating a photoreceptor in cytochrome c oxidase (complex IV) or by reducing water viscosity around ATP synthase motors.

Seheult’s team doesn’t reject these mechanisms—but argues they’re incomplete.

The Marcus framework explains phenomena earlier models couldn’t: why some infrared wavelengths inhibit rather than enhance mitochondrial activity, why broadband light outperforms monochromatic sources, and why effects persist across vastly different organisms.

The paper is the first to integrate four separate literature streams:

• Mitochondrial electron transfer follows Marcus physics
• Red and near-infrared light alter mitochondrial function
• Water and protein structures affect electron transfer kinetics
• Infrared radiation changes molecular electron transfer rates

“The novelty lies in the mechanistic integration,” Seheult emphasizes, “not in any single component.”

What Comes Next

The hypothesis is testable. Future experiments could measure how different infrared wavelengths alter specific Marcus crossing configurations in isolated mitochondrial complexes, or track real-time changes in reorganization energy using advanced spectroscopy.

If validated, the implications extend far beyond biology. Urban planning, architecture, workplace design, and lighting standards may all need reconsideration.

Seheult introduces a new term: photometabolism—solar-driven, non-photosynthetic modulation of core metabolic processes.

It’s a concept that positions sunlight not as a passive environmental factor, but as an active participant in the biochemistry of life itself.

I believe that this hypothesis if true has major implications for the built environment and how we live and the type of light that we require to live, and I believe it’s one of the major reasons why we need to be treating our patients outside.

Sources

• Jeffery et al. (2025) – Longer wavelengths in sunlight penetrating human tissue
• Ma et al. (2018) – Infrared perturbation of charge separation and recombination
• Sanderson et al. (2018) – Inhibitory modulation of cytochrome c oxidase with near-infrared wavelengths
• Dai et al. (2026) – Infrared stimulation of mitochondrial metabolism in deep-sea yeast
• Hayashi et al. (2010) – Water-mediated electron transfer in iron-sulfur bridges
• Marcus and Sutin (1985) – Electron transfer reactions in chemistry

Why Sunlight Penetrates Deeper Than You Think

Most people assume sunlight only affects the skin surface. But research published in 2025 by Dr. Glenn Jeffery’s group demonstrated that longer wavelengths of infrared light can pass completely through human tissue.

Light is able to go through the body. It is able to be absorbed and it is doing stuff in the body.

In one striking experiment, 850-nanometer light was shown passing through a human hand with measurable intensity on the other side. Infrared wavelengths between 750 and 1,000 nanometers can even penetrate clothing.

This discovery opens the door to a startling possibility: infrared photons from the sun may be reaching mitochondria deep inside the body and influencing their activity in real time.

The Sun’s Special Infrared Signature

Not all light sources are created equal. The sun emits a broad spectrum of infrared wavelengths, but one particular photon energy—0.754 electron volts—is especially abundant.

This peak occurs because of the sun’s photosphere, a layer rich in negatively charged hydrogen atoms called hydride ions. These ions absorb higher-energy photons and re-emit them at exactly 0.754 electron volts.

Seheult likens it to dollar bills falling from the sky. While visible light carries the most total energy (like $100 bills), infrared photons are the most numerous (like $1 bills).

The result? A unique atmospheric window that allows these photons to reach Earth’s surface in abundance—and potentially interact with living cells in ways artificial light cannot replicate.

Marcus Electron Transfer: The Physics Behind the Biology

To understand how infrared light affects mitochondria, Seheult’s team turned to Marcus electron transfer theory, pioneered by Nobel laureate Rudolph Marcus in the 1960s.

Electrons don’t jump spontaneously between molecules. They require surrounding proteins, water, and lipids to twist into precise configurations—a process that demands energy called “reorganization energy.”

When infrared light hits these structures, it causes them to vibrate. This shifts the probability that molecules will be in the right arrangement for electron transfer to occur.

• If the crossing point is already accessible: Infrared light can push molecules away from optimal configurations, slowing electron transfer
• If the crossing point requires activation: Infrared light can push molecules toward optimal configurations, speeding electron transfer

This explains a puzzling finding from earlier studies: different infrared wavelengths can either increase or decrease mitochondrial activity.

Experiments Confirm the Mechanism

A 2018 study by Ma and colleagues tested this exact principle. Researchers built a custom molecule and used mid-infrared light to excite vibrational modes.

They found infrared light slowed forward electron transfer but accelerated backward transfer—precisely what Marcus theory predicts when nuclear orientations are shifted along energy curves.

IR excitation increases the probability of donor and acceptor energies to remain in degeneracy, resulting in IR-induced electron transfer rate enhancement.

Seheult notes he and co-author Dr. Robert Fosbury spoke with Marcus himself—just months before the scientist passed away at age 102—to discuss their hypothesis.

Deep-Sea Yeast Thrives on Infrared Light—Without Photosynthesis

Perhaps the most striking evidence comes from an unexpected source: yeast living near hydrothermal vents at the bottom of the ocean.

A 2026 study by Dai and colleagues isolated yeast from sediments near a “black smoker” chimney in the central Indian Ocean, more than half a meter from superheated mineral plumes reaching 378°C.

When researchers exposed these yeast cultures to near-infrared light (810–1050 nm) in temperature-controlled conditions, growth increased dramatically compared to dark controls—even though the yeast cannot photosynthesize.

Infrared light outperformed glucose. Adding glucose increased biomass by only 1.3-fold (not statistically significant), while 880-nanometer infrared light produced a threefold increase.

When researchers blocked cytochrome c oxidase (complex IV in mitochondria), near-infrared-stimulated growth dropped by 44%—suggesting the effect operates directly on mitochondrial machinery.

Cold Temperatures, Warm Light

Even more remarkable: infrared light allowed yeast to grow at cooler temperatures where dark controls remained dormant.

At 20°C, yeast exposed to 880-nanometer light grew vigorously while dark controls showed minimal activity. The effective activation energy dropped from 12 kilocalories per mole to just 2 kilocalories per mole.

Infrared light was making up for the cold temperatures by supplying vibrational activation rather than thermal activation.

Proteomics revealed the most upregulated protein after infrared exposure was a mitochondrial ribosomal protein (MRPs8), increased 6.7-fold.

Why Broadband Sunlight May Beat Monochromatic LEDs

Clinical studies using single-wavelength infrared devices have shown benefits—from reducing ICU length of stay to improving muscle strength in COVID-19 patients.

But Seheult’s hypothesis suggests broadband infrared from the sun may be even more effective.

“Sunlight contains a broad spectrum of wavelengths that can interact with many different vibrational modes and electron transfer steps,” he explains, “rather than targeting only one narrow pathway.”

Research from Jeffery’s lab supports this. When comparing monochromatic 850-nanometer light to a 60-watt incandescent bulb (which emits broad-spectrum infrared), the incandescent bulb produced greater improvements in color blindness.

• Monochromatic 850 nm: 9% improvement (head and body), 5% (body only)
• 60W incandescent bulb: 28% improvement, sustained for weeks

The research here aligns with the hypothesis, though direct mechanistic proof in human mitochondria remains to be demonstrated.

The Modern Indoor Environment: A Metabolic Desert?

LED bulbs emit virtually no infrared radiation. Low-emissivity (Low-E) glass windows, designed to improve energy efficiency, block infrared wavelengths.

Seheult measured infrared exposure in his own dining room with windows open: 0.8 watts per square meter.

Step outside under a shade tree with grass reflecting sunlight? 41.9 watts per square meter—more than 50 times higher.

We have set up a situation where outdoors we’re getting plenty of infrared light, versus being indoors where we have Low-E glass blocking it and LED bulbs producing none.

This raises profound questions about whether chronic infrared deficiency could contribute to the rising burden of metabolic diseases, especially among populations spending most of their time indoors.

Seasonal Mortality Patterns Point to Sunlight’s Role

Death rates from heart disease, cancer, stroke, Alzheimer’s, diabetes, and respiratory illness all peak one to three weeks after the shortest day of the year and bottom out after the longest day.

This pattern holds across both infectious and non-infectious causes. The seasonal variation in heart disease deaths alone exceeds total influenza deaths during flu season.

Australia shows the same pattern, but shifted six months—deaths peak in July, their winter. Singapore, 80 miles from the equator with year-round sun, shows no seasonal mortality pattern.

Multiple studies have linked mortality rates to latitude, independent of vitamin D levels, suggesting sunlight itself—particularly its infrared component—plays a direct metabolic role.

Hospitals Are Bringing Patients Outside

Armed with mounting evidence, hospitals worldwide are redesigning care spaces to maximize sunlight exposure.

A $1.5 billion hospital in Footscray, Australia, built ICU beds with direct outdoor access. King’s College Hospital in London invested £2 million to transform its rooftop into a critical care garden where up to six ICU patients can receive treatment surrounded by greenery and natural light.

St. George’s Hospital in London followed suit, creating a neurointensive care rooftop unit. Queen Camilla visited the facility in 2026 to recognize the innovation.

Randomized controlled trials using infrared vests delivering roughly 20–30 watts per square meter (comparable to sitting under a tree) showed 30% reductions in ICU length of stay and improved muscle strength in critically ill COVID-19 patients.

Metabolic Scaling Matches Solar Power Scaling

One of the paper’s most intriguing observations: metabolic rate scales with body mass to the 3/4 power across species from flies to elephants.

Solar power intercepted by an organism also scales to the 3/4 power of mass—nearly identical.

This doesn’t prove causation, but it suggests sunlight could be a universal regulator of metabolic activity across the biosphere, with mitochondria in all organisms tuned to respond to the same infrared wavelengths present in Earth’s solar photon field.

What Makes This Hypothesis Different

Earlier theories proposed infrared light works by activating a photoreceptor in cytochrome c oxidase (complex IV) or by reducing water viscosity around ATP synthase motors.

Seheult’s team doesn’t reject these mechanisms—but argues they’re incomplete.

The Marcus framework explains phenomena earlier models couldn’t: why some infrared wavelengths inhibit rather than enhance mitochondrial activity, why broadband light outperforms monochromatic sources, and why effects persist across vastly different organisms.

The paper is the first to integrate four separate literature streams:

• Mitochondrial electron transfer follows Marcus physics
• Red and near-infrared light alter mitochondrial function
• Water and protein structures affect electron transfer kinetics
• Infrared radiation changes molecular electron transfer rates

“The novelty lies in the mechanistic integration,” Seheult emphasizes, “not in any single component.”

What Comes Next

The hypothesis is testable. Future experiments could measure how different infrared wavelengths alter specific Marcus crossing configurations in isolated mitochondrial complexes, or track real-time changes in reorganization energy using advanced spectroscopy.

If validated, the implications extend far beyond biology. Urban planning, architecture, workplace design, and lighting standards may all need reconsideration.

Seheult introduces a new term: photometabolism—solar-driven, non-photosynthetic modulation of core metabolic processes.

It’s a concept that positions sunlight not as a passive environmental factor, but as an active participant in the biochemistry of life itself.

I believe that this hypothesis if true has major implications for the built environment and how we live and the type of light that we require to live, and I believe it’s one of the major reasons why we need to be treating our patients outside.

Sources

• Jeffery et al. (2025) – Longer wavelengths in sunlight penetrating human tissue
• Ma et al. (2018) – Infrared perturbation of charge separation and recombination
• Sanderson et al. (2018) – Inhibitory modulation of cytochrome c oxidase with near-infrared wavelengths
• Dai et al. (2026) – Infrared stimulation of mitochondrial metabolism in deep-sea yeast
• Hayashi et al. (2010) – Water-mediated electron transfer in iron-sulfur bridges
• Marcus and Sutin (1985) – Electron transfer reactions in chemistry

Unlike previous theories that focused on a single photoreceptor in one mitochondrial protein, this new framework suggests infrared light works across multiple pathways simultaneously by altering the vibrational energy of proteins, water, and lipids that surround electron transfer sites.

Why Sunlight Penetrates Deeper Than You Think

Most people assume sunlight only affects the skin surface. But research published in 2025 by Dr. Glenn Jeffery’s group demonstrated that longer wavelengths of infrared light can pass completely through human tissue.

Light is able to go through the body. It is able to be absorbed and it is doing stuff in the body.

In one striking experiment, 850-nanometer light was shown passing through a human hand with measurable intensity on the other side. Infrared wavelengths between 750 and 1,000 nanometers can even penetrate clothing.

This discovery opens the door to a startling possibility: infrared photons from the sun may be reaching mitochondria deep inside the body and influencing their activity in real time.

The Sun’s Special Infrared Signature

Not all light sources are created equal. The sun emits a broad spectrum of infrared wavelengths, but one particular photon energy—0.754 electron volts—is especially abundant.

This peak occurs because of the sun’s photosphere, a layer rich in negatively charged hydrogen atoms called hydride ions. These ions absorb higher-energy photons and re-emit them at exactly 0.754 electron volts.

Seheult likens it to dollar bills falling from the sky. While visible light carries the most total energy (like $100 bills), infrared photons are the most numerous (like $1 bills).

The result? A unique atmospheric window that allows these photons to reach Earth’s surface in abundance—and potentially interact with living cells in ways artificial light cannot replicate.

Marcus Electron Transfer: The Physics Behind the Biology

To understand how infrared light affects mitochondria, Seheult’s team turned to Marcus electron transfer theory, pioneered by Nobel laureate Rudolph Marcus in the 1960s.

Electrons don’t jump spontaneously between molecules. They require surrounding proteins, water, and lipids to twist into precise configurations—a process that demands energy called “reorganization energy.”

When infrared light hits these structures, it causes them to vibrate. This shifts the probability that molecules will be in the right arrangement for electron transfer to occur.

• If the crossing point is already accessible: Infrared light can push molecules away from optimal configurations, slowing electron transfer
• If the crossing point requires activation: Infrared light can push molecules toward optimal configurations, speeding electron transfer

This explains a puzzling finding from earlier studies: different infrared wavelengths can either increase or decrease mitochondrial activity.

Experiments Confirm the Mechanism

A 2018 study by Ma and colleagues tested this exact principle. Researchers built a custom molecule and used mid-infrared light to excite vibrational modes.

They found infrared light slowed forward electron transfer but accelerated backward transfer—precisely what Marcus theory predicts when nuclear orientations are shifted along energy curves.

IR excitation increases the probability of donor and acceptor energies to remain in degeneracy, resulting in IR-induced electron transfer rate enhancement.

Seheult notes he and co-author Dr. Robert Fosbury spoke with Marcus himself—just months before the scientist passed away at age 102—to discuss their hypothesis.

Deep-Sea Yeast Thrives on Infrared Light—Without Photosynthesis

Perhaps the most striking evidence comes from an unexpected source: yeast living near hydrothermal vents at the bottom of the ocean.

A 2026 study by Dai and colleagues isolated yeast from sediments near a “black smoker” chimney in the central Indian Ocean, more than half a meter from superheated mineral plumes reaching 378°C.

When researchers exposed these yeast cultures to near-infrared light (810–1050 nm) in temperature-controlled conditions, growth increased dramatically compared to dark controls—even though the yeast cannot photosynthesize.

Infrared light outperformed glucose. Adding glucose increased biomass by only 1.3-fold (not statistically significant), while 880-nanometer infrared light produced a threefold increase.

When researchers blocked cytochrome c oxidase (complex IV in mitochondria), near-infrared-stimulated growth dropped by 44%—suggesting the effect operates directly on mitochondrial machinery.

Cold Temperatures, Warm Light

Even more remarkable: infrared light allowed yeast to grow at cooler temperatures where dark controls remained dormant.

At 20°C, yeast exposed to 880-nanometer light grew vigorously while dark controls showed minimal activity. The effective activation energy dropped from 12 kilocalories per mole to just 2 kilocalories per mole.

Infrared light was making up for the cold temperatures by supplying vibrational activation rather than thermal activation.

Proteomics revealed the most upregulated protein after infrared exposure was a mitochondrial ribosomal protein (MRPs8), increased 6.7-fold.

Why Broadband Sunlight May Beat Monochromatic LEDs

Clinical studies using single-wavelength infrared devices have shown benefits—from reducing ICU length of stay to improving muscle strength in COVID-19 patients.

But Seheult’s hypothesis suggests broadband infrared from the sun may be even more effective.

“Sunlight contains a broad spectrum of wavelengths that can interact with many different vibrational modes and electron transfer steps,” he explains, “rather than targeting only one narrow pathway.”

Research from Jeffery’s lab supports this. When comparing monochromatic 850-nanometer light to a 60-watt incandescent bulb (which emits broad-spectrum infrared), the incandescent bulb produced greater improvements in color blindness.

• Monochromatic 850 nm: 9% improvement (head and body), 5% (body only)
• 60W incandescent bulb: 28% improvement, sustained for weeks

The research here aligns with the hypothesis, though direct mechanistic proof in human mitochondria remains to be demonstrated.

The Modern Indoor Environment: A Metabolic Desert?

LED bulbs emit virtually no infrared radiation. Low-emissivity (Low-E) glass windows, designed to improve energy efficiency, block infrared wavelengths.

Seheult measured infrared exposure in his own dining room with windows open: 0.8 watts per square meter.

Step outside under a shade tree with grass reflecting sunlight? 41.9 watts per square meter—more than 50 times higher.

We have set up a situation where outdoors we’re getting plenty of infrared light, versus being indoors where we have Low-E glass blocking it and LED bulbs producing none.

This raises profound questions about whether chronic infrared deficiency could contribute to the rising burden of metabolic diseases, especially among populations spending most of their time indoors.

Seasonal Mortality Patterns Point to Sunlight’s Role

Death rates from heart disease, cancer, stroke, Alzheimer’s, diabetes, and respiratory illness all peak one to three weeks after the shortest day of the year and bottom out after the longest day.

This pattern holds across both infectious and non-infectious causes. The seasonal variation in heart disease deaths alone exceeds total influenza deaths during flu season.

Australia shows the same pattern, but shifted six months—deaths peak in July, their winter. Singapore, 80 miles from the equator with year-round sun, shows no seasonal mortality pattern.

Multiple studies have linked mortality rates to latitude, independent of vitamin D levels, suggesting sunlight itself—particularly its infrared component—plays a direct metabolic role.

Hospitals Are Bringing Patients Outside

Armed with mounting evidence, hospitals worldwide are redesigning care spaces to maximize sunlight exposure.

A $1.5 billion hospital in Footscray, Australia, built ICU beds with direct outdoor access. King’s College Hospital in London invested £2 million to transform its rooftop into a critical care garden where up to six ICU patients can receive treatment surrounded by greenery and natural light.

St. George’s Hospital in London followed suit, creating a neurointensive care rooftop unit. Queen Camilla visited the facility in 2026 to recognize the innovation.

Randomized controlled trials using infrared vests delivering roughly 20–30 watts per square meter (comparable to sitting under a tree) showed 30% reductions in ICU length of stay and improved muscle strength in critically ill COVID-19 patients.

Metabolic Scaling Matches Solar Power Scaling

One of the paper’s most intriguing observations: metabolic rate scales with body mass to the 3/4 power across species from flies to elephants.

Solar power intercepted by an organism also scales to the 3/4 power of mass—nearly identical.

This doesn’t prove causation, but it suggests sunlight could be a universal regulator of metabolic activity across the biosphere, with mitochondria in all organisms tuned to respond to the same infrared wavelengths present in Earth’s solar photon field.

What Makes This Hypothesis Different

Earlier theories proposed infrared light works by activating a photoreceptor in cytochrome c oxidase (complex IV) or by reducing water viscosity around ATP synthase motors.

Seheult’s team doesn’t reject these mechanisms—but argues they’re incomplete.

The Marcus framework explains phenomena earlier models couldn’t: why some infrared wavelengths inhibit rather than enhance mitochondrial activity, why broadband light outperforms monochromatic sources, and why effects persist across vastly different organisms.

The paper is the first to integrate four separate literature streams:

• Mitochondrial electron transfer follows Marcus physics
• Red and near-infrared light alter mitochondrial function
• Water and protein structures affect electron transfer kinetics
• Infrared radiation changes molecular electron transfer rates

“The novelty lies in the mechanistic integration,” Seheult emphasizes, “not in any single component.”

What Comes Next

The hypothesis is testable. Future experiments could measure how different infrared wavelengths alter specific Marcus crossing configurations in isolated mitochondrial complexes, or track real-time changes in reorganization energy using advanced spectroscopy.

If validated, the implications extend far beyond biology. Urban planning, architecture, workplace design, and lighting standards may all need reconsideration.

Seheult introduces a new term: photometabolism—solar-driven, non-photosynthetic modulation of core metabolic processes.

It’s a concept that positions sunlight not as a passive environmental factor, but as an active participant in the biochemistry of life itself.

I believe that this hypothesis if true has major implications for the built environment and how we live and the type of light that we require to live, and I believe it’s one of the major reasons why we need to be treating our patients outside.

Sources

• Jeffery et al. (2025) – Longer wavelengths in sunlight penetrating human tissue
• Ma et al. (2018) – Infrared perturbation of charge separation and recombination
• Sanderson et al. (2018) – Inhibitory modulation of cytochrome c oxidase with near-infrared wavelengths
• Dai et al. (2026) – Infrared stimulation of mitochondrial metabolism in deep-sea yeast
• Hayashi et al. (2010) – Water-mediated electron transfer in iron-sulfur bridges
• Marcus and Sutin (1985) – Electron transfer reactions in chemistry

Unlike previous theories that focused on a single photoreceptor in one mitochondrial protein, this new framework suggests infrared light works across multiple pathways simultaneously by altering the vibrational energy of proteins, water, and lipids that surround electron transfer sites.

Why Sunlight Penetrates Deeper Than You Think

Most people assume sunlight only affects the skin surface. But research published in 2025 by Dr. Glenn Jeffery’s group demonstrated that longer wavelengths of infrared light can pass completely through human tissue.

Light is able to go through the body. It is able to be absorbed and it is doing stuff in the body.

In one striking experiment, 850-nanometer light was shown passing through a human hand with measurable intensity on the other side. Infrared wavelengths between 750 and 1,000 nanometers can even penetrate clothing.

This discovery opens the door to a startling possibility: infrared photons from the sun may be reaching mitochondria deep inside the body and influencing their activity in real time.

The Sun’s Special Infrared Signature

Not all light sources are created equal. The sun emits a broad spectrum of infrared wavelengths, but one particular photon energy—0.754 electron volts—is especially abundant.

This peak occurs because of the sun’s photosphere, a layer rich in negatively charged hydrogen atoms called hydride ions. These ions absorb higher-energy photons and re-emit them at exactly 0.754 electron volts.

Seheult likens it to dollar bills falling from the sky. While visible light carries the most total energy (like $100 bills), infrared photons are the most numerous (like $1 bills).

The result? A unique atmospheric window that allows these photons to reach Earth’s surface in abundance—and potentially interact with living cells in ways artificial light cannot replicate.

Marcus Electron Transfer: The Physics Behind the Biology

To understand how infrared light affects mitochondria, Seheult’s team turned to Marcus electron transfer theory, pioneered by Nobel laureate Rudolph Marcus in the 1960s.

Electrons don’t jump spontaneously between molecules. They require surrounding proteins, water, and lipids to twist into precise configurations—a process that demands energy called “reorganization energy.”

When infrared light hits these structures, it causes them to vibrate. This shifts the probability that molecules will be in the right arrangement for electron transfer to occur.

• If the crossing point is already accessible: Infrared light can push molecules away from optimal configurations, slowing electron transfer
• If the crossing point requires activation: Infrared light can push molecules toward optimal configurations, speeding electron transfer

This explains a puzzling finding from earlier studies: different infrared wavelengths can either increase or decrease mitochondrial activity.

Experiments Confirm the Mechanism

A 2018 study by Ma and colleagues tested this exact principle. Researchers built a custom molecule and used mid-infrared light to excite vibrational modes.

They found infrared light slowed forward electron transfer but accelerated backward transfer—precisely what Marcus theory predicts when nuclear orientations are shifted along energy curves.

IR excitation increases the probability of donor and acceptor energies to remain in degeneracy, resulting in IR-induced electron transfer rate enhancement.

Seheult notes he and co-author Dr. Robert Fosbury spoke with Marcus himself—just months before the scientist passed away at age 102—to discuss their hypothesis.

Deep-Sea Yeast Thrives on Infrared Light—Without Photosynthesis

Perhaps the most striking evidence comes from an unexpected source: yeast living near hydrothermal vents at the bottom of the ocean.

A 2026 study by Dai and colleagues isolated yeast from sediments near a “black smoker” chimney in the central Indian Ocean, more than half a meter from superheated mineral plumes reaching 378°C.

When researchers exposed these yeast cultures to near-infrared light (810–1050 nm) in temperature-controlled conditions, growth increased dramatically compared to dark controls—even though the yeast cannot photosynthesize.

Infrared light outperformed glucose. Adding glucose increased biomass by only 1.3-fold (not statistically significant), while 880-nanometer infrared light produced a threefold increase.

When researchers blocked cytochrome c oxidase (complex IV in mitochondria), near-infrared-stimulated growth dropped by 44%—suggesting the effect operates directly on mitochondrial machinery.

Cold Temperatures, Warm Light

Even more remarkable: infrared light allowed yeast to grow at cooler temperatures where dark controls remained dormant.

At 20°C, yeast exposed to 880-nanometer light grew vigorously while dark controls showed minimal activity. The effective activation energy dropped from 12 kilocalories per mole to just 2 kilocalories per mole.

Infrared light was making up for the cold temperatures by supplying vibrational activation rather than thermal activation.

Proteomics revealed the most upregulated protein after infrared exposure was a mitochondrial ribosomal protein (MRPs8), increased 6.7-fold.

Why Broadband Sunlight May Beat Monochromatic LEDs

Clinical studies using single-wavelength infrared devices have shown benefits—from reducing ICU length of stay to improving muscle strength in COVID-19 patients.

But Seheult’s hypothesis suggests broadband infrared from the sun may be even more effective.

“Sunlight contains a broad spectrum of wavelengths that can interact with many different vibrational modes and electron transfer steps,” he explains, “rather than targeting only one narrow pathway.”

Research from Jeffery’s lab supports this. When comparing monochromatic 850-nanometer light to a 60-watt incandescent bulb (which emits broad-spectrum infrared), the incandescent bulb produced greater improvements in color blindness.

• Monochromatic 850 nm: 9% improvement (head and body), 5% (body only)
• 60W incandescent bulb: 28% improvement, sustained for weeks

The research here aligns with the hypothesis, though direct mechanistic proof in human mitochondria remains to be demonstrated.

The Modern Indoor Environment: A Metabolic Desert?

LED bulbs emit virtually no infrared radiation. Low-emissivity (Low-E) glass windows, designed to improve energy efficiency, block infrared wavelengths.

Seheult measured infrared exposure in his own dining room with windows open: 0.8 watts per square meter.

Step outside under a shade tree with grass reflecting sunlight? 41.9 watts per square meter—more than 50 times higher.

We have set up a situation where outdoors we’re getting plenty of infrared light, versus being indoors where we have Low-E glass blocking it and LED bulbs producing none.

This raises profound questions about whether chronic infrared deficiency could contribute to the rising burden of metabolic diseases, especially among populations spending most of their time indoors.

Seasonal Mortality Patterns Point to Sunlight’s Role

Death rates from heart disease, cancer, stroke, Alzheimer’s, diabetes, and respiratory illness all peak one to three weeks after the shortest day of the year and bottom out after the longest day.

This pattern holds across both infectious and non-infectious causes. The seasonal variation in heart disease deaths alone exceeds total influenza deaths during flu season.

Australia shows the same pattern, but shifted six months—deaths peak in July, their winter. Singapore, 80 miles from the equator with year-round sun, shows no seasonal mortality pattern.

Multiple studies have linked mortality rates to latitude, independent of vitamin D levels, suggesting sunlight itself—particularly its infrared component—plays a direct metabolic role.

Hospitals Are Bringing Patients Outside

Armed with mounting evidence, hospitals worldwide are redesigning care spaces to maximize sunlight exposure.

A $1.5 billion hospital in Footscray, Australia, built ICU beds with direct outdoor access. King’s College Hospital in London invested £2 million to transform its rooftop into a critical care garden where up to six ICU patients can receive treatment surrounded by greenery and natural light.

St. George’s Hospital in London followed suit, creating a neurointensive care rooftop unit. Queen Camilla visited the facility in 2026 to recognize the innovation.

Randomized controlled trials using infrared vests delivering roughly 20–30 watts per square meter (comparable to sitting under a tree) showed 30% reductions in ICU length of stay and improved muscle strength in critically ill COVID-19 patients.

Metabolic Scaling Matches Solar Power Scaling

One of the paper’s most intriguing observations: metabolic rate scales with body mass to the 3/4 power across species from flies to elephants.

Solar power intercepted by an organism also scales to the 3/4 power of mass—nearly identical.

This doesn’t prove causation, but it suggests sunlight could be a universal regulator of metabolic activity across the biosphere, with mitochondria in all organisms tuned to respond to the same infrared wavelengths present in Earth’s solar photon field.

What Makes This Hypothesis Different

Earlier theories proposed infrared light works by activating a photoreceptor in cytochrome c oxidase (complex IV) or by reducing water viscosity around ATP synthase motors.

Seheult’s team doesn’t reject these mechanisms—but argues they’re incomplete.

The Marcus framework explains phenomena earlier models couldn’t: why some infrared wavelengths inhibit rather than enhance mitochondrial activity, why broadband light outperforms monochromatic sources, and why effects persist across vastly different organisms.

The paper is the first to integrate four separate literature streams:

• Mitochondrial electron transfer follows Marcus physics
• Red and near-infrared light alter mitochondrial function
• Water and protein structures affect electron transfer kinetics
• Infrared radiation changes molecular electron transfer rates

“The novelty lies in the mechanistic integration,” Seheult emphasizes, “not in any single component.”

What Comes Next

The hypothesis is testable. Future experiments could measure how different infrared wavelengths alter specific Marcus crossing configurations in isolated mitochondrial complexes, or track real-time changes in reorganization energy using advanced spectroscopy.

If validated, the implications extend far beyond biology. Urban planning, architecture, workplace design, and lighting standards may all need reconsideration.

Seheult introduces a new term: photometabolism—solar-driven, non-photosynthetic modulation of core metabolic processes.

It’s a concept that positions sunlight not as a passive environmental factor, but as an active participant in the biochemistry of life itself.

I believe that this hypothesis if true has major implications for the built environment and how we live and the type of light that we require to live, and I believe it’s one of the major reasons why we need to be treating our patients outside.

Sources

• Jeffery et al. (2025) – Longer wavelengths in sunlight penetrating human tissue
• Ma et al. (2018) – Infrared perturbation of charge separation and recombination
• Sanderson et al. (2018) – Inhibitory modulation of cytochrome c oxidase with near-infrared wavelengths
• Dai et al. (2026) – Infrared stimulation of mitochondrial metabolism in deep-sea yeast
• Hayashi et al. (2010) – Water-mediated electron transfer in iron-sulfur bridges
• Marcus and Sutin (1985) – Electron transfer reactions in chemistry

“Electrons move best when the surrounding molecules are arranged just right,” Seheult explains. “Infrared light causes those molecules to vibrate, changing how often the mitochondria reach those favorable arrangements.”

Unlike previous theories that focused on a single photoreceptor in one mitochondrial protein, this new framework suggests infrared light works across multiple pathways simultaneously by altering the vibrational energy of proteins, water, and lipids that surround electron transfer sites.

Why Sunlight Penetrates Deeper Than You Think

Most people assume sunlight only affects the skin surface. But research published in 2025 by Dr. Glenn Jeffery’s group demonstrated that longer wavelengths of infrared light can pass completely through human tissue.

Light is able to go through the body. It is able to be absorbed and it is doing stuff in the body.

In one striking experiment, 850-nanometer light was shown passing through a human hand with measurable intensity on the other side. Infrared wavelengths between 750 and 1,000 nanometers can even penetrate clothing.

This discovery opens the door to a startling possibility: infrared photons from the sun may be reaching mitochondria deep inside the body and influencing their activity in real time.

The Sun’s Special Infrared Signature

Not all light sources are created equal. The sun emits a broad spectrum of infrared wavelengths, but one particular photon energy—0.754 electron volts—is especially abundant.

This peak occurs because of the sun’s photosphere, a layer rich in negatively charged hydrogen atoms called hydride ions. These ions absorb higher-energy photons and re-emit them at exactly 0.754 electron volts.

Seheult likens it to dollar bills falling from the sky. While visible light carries the most total energy (like $100 bills), infrared photons are the most numerous (like $1 bills).

The result? A unique atmospheric window that allows these photons to reach Earth’s surface in abundance—and potentially interact with living cells in ways artificial light cannot replicate.

Marcus Electron Transfer: The Physics Behind the Biology

To understand how infrared light affects mitochondria, Seheult’s team turned to Marcus electron transfer theory, pioneered by Nobel laureate Rudolph Marcus in the 1960s.

Electrons don’t jump spontaneously between molecules. They require surrounding proteins, water, and lipids to twist into precise configurations—a process that demands energy called “reorganization energy.”

When infrared light hits these structures, it causes them to vibrate. This shifts the probability that molecules will be in the right arrangement for electron transfer to occur.

• If the crossing point is already accessible: Infrared light can push molecules away from optimal configurations, slowing electron transfer
• If the crossing point requires activation: Infrared light can push molecules toward optimal configurations, speeding electron transfer

This explains a puzzling finding from earlier studies: different infrared wavelengths can either increase or decrease mitochondrial activity.

Experiments Confirm the Mechanism

A 2018 study by Ma and colleagues tested this exact principle. Researchers built a custom molecule and used mid-infrared light to excite vibrational modes.

They found infrared light slowed forward electron transfer but accelerated backward transfer—precisely what Marcus theory predicts when nuclear orientations are shifted along energy curves.

IR excitation increases the probability of donor and acceptor energies to remain in degeneracy, resulting in IR-induced electron transfer rate enhancement.

Seheult notes he and co-author Dr. Robert Fosbury spoke with Marcus himself—just months before the scientist passed away at age 102—to discuss their hypothesis.

Deep-Sea Yeast Thrives on Infrared Light—Without Photosynthesis

Perhaps the most striking evidence comes from an unexpected source: yeast living near hydrothermal vents at the bottom of the ocean.

A 2026 study by Dai and colleagues isolated yeast from sediments near a “black smoker” chimney in the central Indian Ocean, more than half a meter from superheated mineral plumes reaching 378°C.

When researchers exposed these yeast cultures to near-infrared light (810–1050 nm) in temperature-controlled conditions, growth increased dramatically compared to dark controls—even though the yeast cannot photosynthesize.

Infrared light outperformed glucose. Adding glucose increased biomass by only 1.3-fold (not statistically significant), while 880-nanometer infrared light produced a threefold increase.

When researchers blocked cytochrome c oxidase (complex IV in mitochondria), near-infrared-stimulated growth dropped by 44%—suggesting the effect operates directly on mitochondrial machinery.

Cold Temperatures, Warm Light

Even more remarkable: infrared light allowed yeast to grow at cooler temperatures where dark controls remained dormant.

At 20°C, yeast exposed to 880-nanometer light grew vigorously while dark controls showed minimal activity. The effective activation energy dropped from 12 kilocalories per mole to just 2 kilocalories per mole.

Infrared light was making up for the cold temperatures by supplying vibrational activation rather than thermal activation.

Proteomics revealed the most upregulated protein after infrared exposure was a mitochondrial ribosomal protein (MRPs8), increased 6.7-fold.

Why Broadband Sunlight May Beat Monochromatic LEDs

Clinical studies using single-wavelength infrared devices have shown benefits—from reducing ICU length of stay to improving muscle strength in COVID-19 patients.

But Seheult’s hypothesis suggests broadband infrared from the sun may be even more effective.

“Sunlight contains a broad spectrum of wavelengths that can interact with many different vibrational modes and electron transfer steps,” he explains, “rather than targeting only one narrow pathway.”

Research from Jeffery’s lab supports this. When comparing monochromatic 850-nanometer light to a 60-watt incandescent bulb (which emits broad-spectrum infrared), the incandescent bulb produced greater improvements in color blindness.

• Monochromatic 850 nm: 9% improvement (head and body), 5% (body only)
• 60W incandescent bulb: 28% improvement, sustained for weeks

The research here aligns with the hypothesis, though direct mechanistic proof in human mitochondria remains to be demonstrated.

The Modern Indoor Environment: A Metabolic Desert?

LED bulbs emit virtually no infrared radiation. Low-emissivity (Low-E) glass windows, designed to improve energy efficiency, block infrared wavelengths.

Seheult measured infrared exposure in his own dining room with windows open: 0.8 watts per square meter.

Step outside under a shade tree with grass reflecting sunlight? 41.9 watts per square meter—more than 50 times higher.

We have set up a situation where outdoors we’re getting plenty of infrared light, versus being indoors where we have Low-E glass blocking it and LED bulbs producing none.

This raises profound questions about whether chronic infrared deficiency could contribute to the rising burden of metabolic diseases, especially among populations spending most of their time indoors.

Seasonal Mortality Patterns Point to Sunlight’s Role

Death rates from heart disease, cancer, stroke, Alzheimer’s, diabetes, and respiratory illness all peak one to three weeks after the shortest day of the year and bottom out after the longest day.

This pattern holds across both infectious and non-infectious causes. The seasonal variation in heart disease deaths alone exceeds total influenza deaths during flu season.

Australia shows the same pattern, but shifted six months—deaths peak in July, their winter. Singapore, 80 miles from the equator with year-round sun, shows no seasonal mortality pattern.

Multiple studies have linked mortality rates to latitude, independent of vitamin D levels, suggesting sunlight itself—particularly its infrared component—plays a direct metabolic role.

Hospitals Are Bringing Patients Outside

Armed with mounting evidence, hospitals worldwide are redesigning care spaces to maximize sunlight exposure.

A $1.5 billion hospital in Footscray, Australia, built ICU beds with direct outdoor access. King’s College Hospital in London invested £2 million to transform its rooftop into a critical care garden where up to six ICU patients can receive treatment surrounded by greenery and natural light.

St. George’s Hospital in London followed suit, creating a neurointensive care rooftop unit. Queen Camilla visited the facility in 2026 to recognize the innovation.

Randomized controlled trials using infrared vests delivering roughly 20–30 watts per square meter (comparable to sitting under a tree) showed 30% reductions in ICU length of stay and improved muscle strength in critically ill COVID-19 patients.

Metabolic Scaling Matches Solar Power Scaling

One of the paper’s most intriguing observations: metabolic rate scales with body mass to the 3/4 power across species from flies to elephants.

Solar power intercepted by an organism also scales to the 3/4 power of mass—nearly identical.

This doesn’t prove causation, but it suggests sunlight could be a universal regulator of metabolic activity across the biosphere, with mitochondria in all organisms tuned to respond to the same infrared wavelengths present in Earth’s solar photon field.

What Makes This Hypothesis Different

Earlier theories proposed infrared light works by activating a photoreceptor in cytochrome c oxidase (complex IV) or by reducing water viscosity around ATP synthase motors.

Seheult’s team doesn’t reject these mechanisms—but argues they’re incomplete.

The Marcus framework explains phenomena earlier models couldn’t: why some infrared wavelengths inhibit rather than enhance mitochondrial activity, why broadband light outperforms monochromatic sources, and why effects persist across vastly different organisms.

The paper is the first to integrate four separate literature streams:

• Mitochondrial electron transfer follows Marcus physics
• Red and near-infrared light alter mitochondrial function
• Water and protein structures affect electron transfer kinetics
• Infrared radiation changes molecular electron transfer rates

“The novelty lies in the mechanistic integration,” Seheult emphasizes, “not in any single component.”

What Comes Next

The hypothesis is testable. Future experiments could measure how different infrared wavelengths alter specific Marcus crossing configurations in isolated mitochondrial complexes, or track real-time changes in reorganization energy using advanced spectroscopy.

If validated, the implications extend far beyond biology. Urban planning, architecture, workplace design, and lighting standards may all need reconsideration.

Seheult introduces a new term: photometabolism—solar-driven, non-photosynthetic modulation of core metabolic processes.

It’s a concept that positions sunlight not as a passive environmental factor, but as an active participant in the biochemistry of life itself.

I believe that this hypothesis if true has major implications for the built environment and how we live and the type of light that we require to live, and I believe it’s one of the major reasons why we need to be treating our patients outside.

Sources

• Jeffery et al. (2025) – Longer wavelengths in sunlight penetrating human tissue
• Ma et al. (2018) – Infrared perturbation of charge separation and recombination
• Sanderson et al. (2018) – Inhibitory modulation of cytochrome c oxidase with near-infrared wavelengths
• Dai et al. (2026) – Infrared stimulation of mitochondrial metabolism in deep-sea yeast
• Hayashi et al. (2010) – Water-mediated electron transfer in iron-sulfur bridges
• Marcus and Sutin (1985) – Electron transfer reactions in chemistry

“Electrons move best when the surrounding molecules are arranged just right,” Seheult explains. “Infrared light causes those molecules to vibrate, changing how often the mitochondria reach those favorable arrangements.”

Unlike previous theories that focused on a single photoreceptor in one mitochondrial protein, this new framework suggests infrared light works across multiple pathways simultaneously by altering the vibrational energy of proteins, water, and lipids that surround electron transfer sites.

Why Sunlight Penetrates Deeper Than You Think

Most people assume sunlight only affects the skin surface. But research published in 2025 by Dr. Glenn Jeffery’s group demonstrated that longer wavelengths of infrared light can pass completely through human tissue.

Light is able to go through the body. It is able to be absorbed and it is doing stuff in the body.

In one striking experiment, 850-nanometer light was shown passing through a human hand with measurable intensity on the other side. Infrared wavelengths between 750 and 1,000 nanometers can even penetrate clothing.

This discovery opens the door to a startling possibility: infrared photons from the sun may be reaching mitochondria deep inside the body and influencing their activity in real time.

The Sun’s Special Infrared Signature

Not all light sources are created equal. The sun emits a broad spectrum of infrared wavelengths, but one particular photon energy—0.754 electron volts—is especially abundant.

This peak occurs because of the sun’s photosphere, a layer rich in negatively charged hydrogen atoms called hydride ions. These ions absorb higher-energy photons and re-emit them at exactly 0.754 electron volts.

Seheult likens it to dollar bills falling from the sky. While visible light carries the most total energy (like $100 bills), infrared photons are the most numerous (like $1 bills).

The result? A unique atmospheric window that allows these photons to reach Earth’s surface in abundance—and potentially interact with living cells in ways artificial light cannot replicate.

Marcus Electron Transfer: The Physics Behind the Biology

To understand how infrared light affects mitochondria, Seheult’s team turned to Marcus electron transfer theory, pioneered by Nobel laureate Rudolph Marcus in the 1960s.

Electrons don’t jump spontaneously between molecules. They require surrounding proteins, water, and lipids to twist into precise configurations—a process that demands energy called “reorganization energy.”

When infrared light hits these structures, it causes them to vibrate. This shifts the probability that molecules will be in the right arrangement for electron transfer to occur.

• If the crossing point is already accessible: Infrared light can push molecules away from optimal configurations, slowing electron transfer
• If the crossing point requires activation: Infrared light can push molecules toward optimal configurations, speeding electron transfer

This explains a puzzling finding from earlier studies: different infrared wavelengths can either increase or decrease mitochondrial activity.

Experiments Confirm the Mechanism

A 2018 study by Ma and colleagues tested this exact principle. Researchers built a custom molecule and used mid-infrared light to excite vibrational modes.

They found infrared light slowed forward electron transfer but accelerated backward transfer—precisely what Marcus theory predicts when nuclear orientations are shifted along energy curves.

IR excitation increases the probability of donor and acceptor energies to remain in degeneracy, resulting in IR-induced electron transfer rate enhancement.

Seheult notes he and co-author Dr. Robert Fosbury spoke with Marcus himself—just months before the scientist passed away at age 102—to discuss their hypothesis.

Deep-Sea Yeast Thrives on Infrared Light—Without Photosynthesis

Perhaps the most striking evidence comes from an unexpected source: yeast living near hydrothermal vents at the bottom of the ocean.

A 2026 study by Dai and colleagues isolated yeast from sediments near a “black smoker” chimney in the central Indian Ocean, more than half a meter from superheated mineral plumes reaching 378°C.

When researchers exposed these yeast cultures to near-infrared light (810–1050 nm) in temperature-controlled conditions, growth increased dramatically compared to dark controls—even though the yeast cannot photosynthesize.

Infrared light outperformed glucose. Adding glucose increased biomass by only 1.3-fold (not statistically significant), while 880-nanometer infrared light produced a threefold increase.

When researchers blocked cytochrome c oxidase (complex IV in mitochondria), near-infrared-stimulated growth dropped by 44%—suggesting the effect operates directly on mitochondrial machinery.

Cold Temperatures, Warm Light

Even more remarkable: infrared light allowed yeast to grow at cooler temperatures where dark controls remained dormant.

At 20°C, yeast exposed to 880-nanometer light grew vigorously while dark controls showed minimal activity. The effective activation energy dropped from 12 kilocalories per mole to just 2 kilocalories per mole.

Infrared light was making up for the cold temperatures by supplying vibrational activation rather than thermal activation.

Proteomics revealed the most upregulated protein after infrared exposure was a mitochondrial ribosomal protein (MRPs8), increased 6.7-fold.

Why Broadband Sunlight May Beat Monochromatic LEDs

Clinical studies using single-wavelength infrared devices have shown benefits—from reducing ICU length of stay to improving muscle strength in COVID-19 patients.

But Seheult’s hypothesis suggests broadband infrared from the sun may be even more effective.

“Sunlight contains a broad spectrum of wavelengths that can interact with many different vibrational modes and electron transfer steps,” he explains, “rather than targeting only one narrow pathway.”

Research from Jeffery’s lab supports this. When comparing monochromatic 850-nanometer light to a 60-watt incandescent bulb (which emits broad-spectrum infrared), the incandescent bulb produced greater improvements in color blindness.

• Monochromatic 850 nm: 9% improvement (head and body), 5% (body only)
• 60W incandescent bulb: 28% improvement, sustained for weeks

The research here aligns with the hypothesis, though direct mechanistic proof in human mitochondria remains to be demonstrated.

The Modern Indoor Environment: A Metabolic Desert?

LED bulbs emit virtually no infrared radiation. Low-emissivity (Low-E) glass windows, designed to improve energy efficiency, block infrared wavelengths.

Seheult measured infrared exposure in his own dining room with windows open: 0.8 watts per square meter.

Step outside under a shade tree with grass reflecting sunlight? 41.9 watts per square meter—more than 50 times higher.

We have set up a situation where outdoors we’re getting plenty of infrared light, versus being indoors where we have Low-E glass blocking it and LED bulbs producing none.

This raises profound questions about whether chronic infrared deficiency could contribute to the rising burden of metabolic diseases, especially among populations spending most of their time indoors.

Seasonal Mortality Patterns Point to Sunlight’s Role

Death rates from heart disease, cancer, stroke, Alzheimer’s, diabetes, and respiratory illness all peak one to three weeks after the shortest day of the year and bottom out after the longest day.

This pattern holds across both infectious and non-infectious causes. The seasonal variation in heart disease deaths alone exceeds total influenza deaths during flu season.

Australia shows the same pattern, but shifted six months—deaths peak in July, their winter. Singapore, 80 miles from the equator with year-round sun, shows no seasonal mortality pattern.

Multiple studies have linked mortality rates to latitude, independent of vitamin D levels, suggesting sunlight itself—particularly its infrared component—plays a direct metabolic role.

Hospitals Are Bringing Patients Outside

Armed with mounting evidence, hospitals worldwide are redesigning care spaces to maximize sunlight exposure.

A $1.5 billion hospital in Footscray, Australia, built ICU beds with direct outdoor access. King’s College Hospital in London invested £2 million to transform its rooftop into a critical care garden where up to six ICU patients can receive treatment surrounded by greenery and natural light.

St. George’s Hospital in London followed suit, creating a neurointensive care rooftop unit. Queen Camilla visited the facility in 2026 to recognize the innovation.

Randomized controlled trials using infrared vests delivering roughly 20–30 watts per square meter (comparable to sitting under a tree) showed 30% reductions in ICU length of stay and improved muscle strength in critically ill COVID-19 patients.

Metabolic Scaling Matches Solar Power Scaling

One of the paper’s most intriguing observations: metabolic rate scales with body mass to the 3/4 power across species from flies to elephants.

Solar power intercepted by an organism also scales to the 3/4 power of mass—nearly identical.

This doesn’t prove causation, but it suggests sunlight could be a universal regulator of metabolic activity across the biosphere, with mitochondria in all organisms tuned to respond to the same infrared wavelengths present in Earth’s solar photon field.

What Makes This Hypothesis Different

Earlier theories proposed infrared light works by activating a photoreceptor in cytochrome c oxidase (complex IV) or by reducing water viscosity around ATP synthase motors.

Seheult’s team doesn’t reject these mechanisms—but argues they’re incomplete.

The Marcus framework explains phenomena earlier models couldn’t: why some infrared wavelengths inhibit rather than enhance mitochondrial activity, why broadband light outperforms monochromatic sources, and why effects persist across vastly different organisms.

The paper is the first to integrate four separate literature streams:

• Mitochondrial electron transfer follows Marcus physics
• Red and near-infrared light alter mitochondrial function
• Water and protein structures affect electron transfer kinetics
• Infrared radiation changes molecular electron transfer rates

“The novelty lies in the mechanistic integration,” Seheult emphasizes, “not in any single component.”

What Comes Next

The hypothesis is testable. Future experiments could measure how different infrared wavelengths alter specific Marcus crossing configurations in isolated mitochondrial complexes, or track real-time changes in reorganization energy using advanced spectroscopy.

If validated, the implications extend far beyond biology. Urban planning, architecture, workplace design, and lighting standards may all need reconsideration.

Seheult introduces a new term: photometabolism—solar-driven, non-photosynthetic modulation of core metabolic processes.

It’s a concept that positions sunlight not as a passive environmental factor, but as an active participant in the biochemistry of life itself.

I believe that this hypothesis if true has major implications for the built environment and how we live and the type of light that we require to live, and I believe it’s one of the major reasons why we need to be treating our patients outside.

Sources

• Jeffery et al. (2025) – Longer wavelengths in sunlight penetrating human tissue
• Ma et al. (2018) – Infrared perturbation of charge separation and recombination
• Sanderson et al. (2018) – Inhibitory modulation of cytochrome c oxidase with near-infrared wavelengths
• Dai et al. (2026) – Infrared stimulation of mitochondrial metabolism in deep-sea yeast
• Hayashi et al. (2010) – Water-mediated electron transfer in iron-sulfur bridges
• Marcus and Sutin (1985) – Electron transfer reactions in chemistry

Seheult and his collaborators propose that infrared light from the sun acts as a metabolic modulator by influencing how efficiently electrons move through the mitochondrial electron transport chain.

“Electrons move best when the surrounding molecules are arranged just right,” Seheult explains. “Infrared light causes those molecules to vibrate, changing how often the mitochondria reach those favorable arrangements.”

Unlike previous theories that focused on a single photoreceptor in one mitochondrial protein, this new framework suggests infrared light works across multiple pathways simultaneously by altering the vibrational energy of proteins, water, and lipids that surround electron transfer sites.

Why Sunlight Penetrates Deeper Than You Think

Most people assume sunlight only affects the skin surface. But research published in 2025 by Dr. Glenn Jeffery’s group demonstrated that longer wavelengths of infrared light can pass completely through human tissue.

Light is able to go through the body. It is able to be absorbed and it is doing stuff in the body.

In one striking experiment, 850-nanometer light was shown passing through a human hand with measurable intensity on the other side. Infrared wavelengths between 750 and 1,000 nanometers can even penetrate clothing.

This discovery opens the door to a startling possibility: infrared photons from the sun may be reaching mitochondria deep inside the body and influencing their activity in real time.

The Sun’s Special Infrared Signature

Not all light sources are created equal. The sun emits a broad spectrum of infrared wavelengths, but one particular photon energy—0.754 electron volts—is especially abundant.

This peak occurs because of the sun’s photosphere, a layer rich in negatively charged hydrogen atoms called hydride ions. These ions absorb higher-energy photons and re-emit them at exactly 0.754 electron volts.

Seheult likens it to dollar bills falling from the sky. While visible light carries the most total energy (like $100 bills), infrared photons are the most numerous (like $1 bills).

The result? A unique atmospheric window that allows these photons to reach Earth’s surface in abundance—and potentially interact with living cells in ways artificial light cannot replicate.

Marcus Electron Transfer: The Physics Behind the Biology

To understand how infrared light affects mitochondria, Seheult’s team turned to Marcus electron transfer theory, pioneered by Nobel laureate Rudolph Marcus in the 1960s.

Electrons don’t jump spontaneously between molecules. They require surrounding proteins, water, and lipids to twist into precise configurations—a process that demands energy called “reorganization energy.”

When infrared light hits these structures, it causes them to vibrate. This shifts the probability that molecules will be in the right arrangement for electron transfer to occur.

• If the crossing point is already accessible: Infrared light can push molecules away from optimal configurations, slowing electron transfer
• If the crossing point requires activation: Infrared light can push molecules toward optimal configurations, speeding electron transfer

This explains a puzzling finding from earlier studies: different infrared wavelengths can either increase or decrease mitochondrial activity.

Experiments Confirm the Mechanism

A 2018 study by Ma and colleagues tested this exact principle. Researchers built a custom molecule and used mid-infrared light to excite vibrational modes.

They found infrared light slowed forward electron transfer but accelerated backward transfer—precisely what Marcus theory predicts when nuclear orientations are shifted along energy curves.

IR excitation increases the probability of donor and acceptor energies to remain in degeneracy, resulting in IR-induced electron transfer rate enhancement.

Seheult notes he and co-author Dr. Robert Fosbury spoke with Marcus himself—just months before the scientist passed away at age 102—to discuss their hypothesis.

Deep-Sea Yeast Thrives on Infrared Light—Without Photosynthesis

Perhaps the most striking evidence comes from an unexpected source: yeast living near hydrothermal vents at the bottom of the ocean.

A 2026 study by Dai and colleagues isolated yeast from sediments near a “black smoker” chimney in the central Indian Ocean, more than half a meter from superheated mineral plumes reaching 378°C.

When researchers exposed these yeast cultures to near-infrared light (810–1050 nm) in temperature-controlled conditions, growth increased dramatically compared to dark controls—even though the yeast cannot photosynthesize.

Infrared light outperformed glucose. Adding glucose increased biomass by only 1.3-fold (not statistically significant), while 880-nanometer infrared light produced a threefold increase.

When researchers blocked cytochrome c oxidase (complex IV in mitochondria), near-infrared-stimulated growth dropped by 44%—suggesting the effect operates directly on mitochondrial machinery.

Cold Temperatures, Warm Light

Even more remarkable: infrared light allowed yeast to grow at cooler temperatures where dark controls remained dormant.

At 20°C, yeast exposed to 880-nanometer light grew vigorously while dark controls showed minimal activity. The effective activation energy dropped from 12 kilocalories per mole to just 2 kilocalories per mole.

Infrared light was making up for the cold temperatures by supplying vibrational activation rather than thermal activation.

Proteomics revealed the most upregulated protein after infrared exposure was a mitochondrial ribosomal protein (MRPs8), increased 6.7-fold.

Why Broadband Sunlight May Beat Monochromatic LEDs

Clinical studies using single-wavelength infrared devices have shown benefits—from reducing ICU length of stay to improving muscle strength in COVID-19 patients.

But Seheult’s hypothesis suggests broadband infrared from the sun may be even more effective.

“Sunlight contains a broad spectrum of wavelengths that can interact with many different vibrational modes and electron transfer steps,” he explains, “rather than targeting only one narrow pathway.”

Research from Jeffery’s lab supports this. When comparing monochromatic 850-nanometer light to a 60-watt incandescent bulb (which emits broad-spectrum infrared), the incandescent bulb produced greater improvements in color blindness.

• Monochromatic 850 nm: 9% improvement (head and body), 5% (body only)
• 60W incandescent bulb: 28% improvement, sustained for weeks

The research here aligns with the hypothesis, though direct mechanistic proof in human mitochondria remains to be demonstrated.

The Modern Indoor Environment: A Metabolic Desert?

LED bulbs emit virtually no infrared radiation. Low-emissivity (Low-E) glass windows, designed to improve energy efficiency, block infrared wavelengths.

Seheult measured infrared exposure in his own dining room with windows open: 0.8 watts per square meter.

Step outside under a shade tree with grass reflecting sunlight? 41.9 watts per square meter—more than 50 times higher.

We have set up a situation where outdoors we’re getting plenty of infrared light, versus being indoors where we have Low-E glass blocking it and LED bulbs producing none.

This raises profound questions about whether chronic infrared deficiency could contribute to the rising burden of metabolic diseases, especially among populations spending most of their time indoors.

Seasonal Mortality Patterns Point to Sunlight’s Role

Death rates from heart disease, cancer, stroke, Alzheimer’s, diabetes, and respiratory illness all peak one to three weeks after the shortest day of the year and bottom out after the longest day.

This pattern holds across both infectious and non-infectious causes. The seasonal variation in heart disease deaths alone exceeds total influenza deaths during flu season.

Australia shows the same pattern, but shifted six months—deaths peak in July, their winter. Singapore, 80 miles from the equator with year-round sun, shows no seasonal mortality pattern.

Multiple studies have linked mortality rates to latitude, independent of vitamin D levels, suggesting sunlight itself—particularly its infrared component—plays a direct metabolic role.

Hospitals Are Bringing Patients Outside

Armed with mounting evidence, hospitals worldwide are redesigning care spaces to maximize sunlight exposure.

A $1.5 billion hospital in Footscray, Australia, built ICU beds with direct outdoor access. King’s College Hospital in London invested £2 million to transform its rooftop into a critical care garden where up to six ICU patients can receive treatment surrounded by greenery and natural light.

St. George’s Hospital in London followed suit, creating a neurointensive care rooftop unit. Queen Camilla visited the facility in 2026 to recognize the innovation.

Randomized controlled trials using infrared vests delivering roughly 20–30 watts per square meter (comparable to sitting under a tree) showed 30% reductions in ICU length of stay and improved muscle strength in critically ill COVID-19 patients.

Metabolic Scaling Matches Solar Power Scaling

One of the paper’s most intriguing observations: metabolic rate scales with body mass to the 3/4 power across species from flies to elephants.

Solar power intercepted by an organism also scales to the 3/4 power of mass—nearly identical.

This doesn’t prove causation, but it suggests sunlight could be a universal regulator of metabolic activity across the biosphere, with mitochondria in all organisms tuned to respond to the same infrared wavelengths present in Earth’s solar photon field.

What Makes This Hypothesis Different

Earlier theories proposed infrared light works by activating a photoreceptor in cytochrome c oxidase (complex IV) or by reducing water viscosity around ATP synthase motors.

Seheult’s team doesn’t reject these mechanisms—but argues they’re incomplete.

The Marcus framework explains phenomena earlier models couldn’t: why some infrared wavelengths inhibit rather than enhance mitochondrial activity, why broadband light outperforms monochromatic sources, and why effects persist across vastly different organisms.

The paper is the first to integrate four separate literature streams:

• Mitochondrial electron transfer follows Marcus physics
• Red and near-infrared light alter mitochondrial function
• Water and protein structures affect electron transfer kinetics
• Infrared radiation changes molecular electron transfer rates

“The novelty lies in the mechanistic integration,” Seheult emphasizes, “not in any single component.”

What Comes Next

The hypothesis is testable. Future experiments could measure how different infrared wavelengths alter specific Marcus crossing configurations in isolated mitochondrial complexes, or track real-time changes in reorganization energy using advanced spectroscopy.

If validated, the implications extend far beyond biology. Urban planning, architecture, workplace design, and lighting standards may all need reconsideration.

Seheult introduces a new term: photometabolism—solar-driven, non-photosynthetic modulation of core metabolic processes.

It’s a concept that positions sunlight not as a passive environmental factor, but as an active participant in the biochemistry of life itself.

I believe that this hypothesis if true has major implications for the built environment and how we live and the type of light that we require to live, and I believe it’s one of the major reasons why we need to be treating our patients outside.

Sources

• Jeffery et al. (2025) – Longer wavelengths in sunlight penetrating human tissue
• Ma et al. (2018) – Infrared perturbation of charge separation and recombination
• Sanderson et al. (2018) – Inhibitory modulation of cytochrome c oxidase with near-infrared wavelengths
• Dai et al. (2026) – Infrared stimulation of mitochondrial metabolism in deep-sea yeast
• Hayashi et al. (2010) – Water-mediated electron transfer in iron-sulfur bridges
• Marcus and Sutin (1985) – Electron transfer reactions in chemistry

Seheult and his collaborators propose that infrared light from the sun acts as a metabolic modulator by influencing how efficiently electrons move through the mitochondrial electron transport chain.

“Electrons move best when the surrounding molecules are arranged just right,” Seheult explains. “Infrared light causes those molecules to vibrate, changing how often the mitochondria reach those favorable arrangements.”

Unlike previous theories that focused on a single photoreceptor in one mitochondrial protein, this new framework suggests infrared light works across multiple pathways simultaneously by altering the vibrational energy of proteins, water, and lipids that surround electron transfer sites.

Why Sunlight Penetrates Deeper Than You Think

Most people assume sunlight only affects the skin surface. But research published in 2025 by Dr. Glenn Jeffery’s group demonstrated that longer wavelengths of infrared light can pass completely through human tissue.

Light is able to go through the body. It is able to be absorbed and it is doing stuff in the body.

In one striking experiment, 850-nanometer light was shown passing through a human hand with measurable intensity on the other side. Infrared wavelengths between 750 and 1,000 nanometers can even penetrate clothing.

This discovery opens the door to a startling possibility: infrared photons from the sun may be reaching mitochondria deep inside the body and influencing their activity in real time.

The Sun’s Special Infrared Signature

Not all light sources are created equal. The sun emits a broad spectrum of infrared wavelengths, but one particular photon energy—0.754 electron volts—is especially abundant.

This peak occurs because of the sun’s photosphere, a layer rich in negatively charged hydrogen atoms called hydride ions. These ions absorb higher-energy photons and re-emit them at exactly 0.754 electron volts.

Seheult likens it to dollar bills falling from the sky. While visible light carries the most total energy (like $100 bills), infrared photons are the most numerous (like $1 bills).

The result? A unique atmospheric window that allows these photons to reach Earth’s surface in abundance—and potentially interact with living cells in ways artificial light cannot replicate.

Marcus Electron Transfer: The Physics Behind the Biology

To understand how infrared light affects mitochondria, Seheult’s team turned to Marcus electron transfer theory, pioneered by Nobel laureate Rudolph Marcus in the 1960s.

Electrons don’t jump spontaneously between molecules. They require surrounding proteins, water, and lipids to twist into precise configurations—a process that demands energy called “reorganization energy.”

When infrared light hits these structures, it causes them to vibrate. This shifts the probability that molecules will be in the right arrangement for electron transfer to occur.

• If the crossing point is already accessible: Infrared light can push molecules away from optimal configurations, slowing electron transfer
• If the crossing point requires activation: Infrared light can push molecules toward optimal configurations, speeding electron transfer

This explains a puzzling finding from earlier studies: different infrared wavelengths can either increase or decrease mitochondrial activity.

Experiments Confirm the Mechanism

A 2018 study by Ma and colleagues tested this exact principle. Researchers built a custom molecule and used mid-infrared light to excite vibrational modes.

They found infrared light slowed forward electron transfer but accelerated backward transfer—precisely what Marcus theory predicts when nuclear orientations are shifted along energy curves.

IR excitation increases the probability of donor and acceptor energies to remain in degeneracy, resulting in IR-induced electron transfer rate enhancement.

Seheult notes he and co-author Dr. Robert Fosbury spoke with Marcus himself—just months before the scientist passed away at age 102—to discuss their hypothesis.

Deep-Sea Yeast Thrives on Infrared Light—Without Photosynthesis

Perhaps the most striking evidence comes from an unexpected source: yeast living near hydrothermal vents at the bottom of the ocean.

A 2026 study by Dai and colleagues isolated yeast from sediments near a “black smoker” chimney in the central Indian Ocean, more than half a meter from superheated mineral plumes reaching 378°C.

When researchers exposed these yeast cultures to near-infrared light (810–1050 nm) in temperature-controlled conditions, growth increased dramatically compared to dark controls—even though the yeast cannot photosynthesize.

Infrared light outperformed glucose. Adding glucose increased biomass by only 1.3-fold (not statistically significant), while 880-nanometer infrared light produced a threefold increase.

When researchers blocked cytochrome c oxidase (complex IV in mitochondria), near-infrared-stimulated growth dropped by 44%—suggesting the effect operates directly on mitochondrial machinery.

Cold Temperatures, Warm Light

Even more remarkable: infrared light allowed yeast to grow at cooler temperatures where dark controls remained dormant.

At 20°C, yeast exposed to 880-nanometer light grew vigorously while dark controls showed minimal activity. The effective activation energy dropped from 12 kilocalories per mole to just 2 kilocalories per mole.

Infrared light was making up for the cold temperatures by supplying vibrational activation rather than thermal activation.

Proteomics revealed the most upregulated protein after infrared exposure was a mitochondrial ribosomal protein (MRPs8), increased 6.7-fold.

Why Broadband Sunlight May Beat Monochromatic LEDs

Clinical studies using single-wavelength infrared devices have shown benefits—from reducing ICU length of stay to improving muscle strength in COVID-19 patients.

But Seheult’s hypothesis suggests broadband infrared from the sun may be even more effective.

“Sunlight contains a broad spectrum of wavelengths that can interact with many different vibrational modes and electron transfer steps,” he explains, “rather than targeting only one narrow pathway.”

Research from Jeffery’s lab supports this. When comparing monochromatic 850-nanometer light to a 60-watt incandescent bulb (which emits broad-spectrum infrared), the incandescent bulb produced greater improvements in color blindness.

• Monochromatic 850 nm: 9% improvement (head and body), 5% (body only)
• 60W incandescent bulb: 28% improvement, sustained for weeks

The research here aligns with the hypothesis, though direct mechanistic proof in human mitochondria remains to be demonstrated.

The Modern Indoor Environment: A Metabolic Desert?

LED bulbs emit virtually no infrared radiation. Low-emissivity (Low-E) glass windows, designed to improve energy efficiency, block infrared wavelengths.

Seheult measured infrared exposure in his own dining room with windows open: 0.8 watts per square meter.

Step outside under a shade tree with grass reflecting sunlight? 41.9 watts per square meter—more than 50 times higher.

We have set up a situation where outdoors we’re getting plenty of infrared light, versus being indoors where we have Low-E glass blocking it and LED bulbs producing none.

This raises profound questions about whether chronic infrared deficiency could contribute to the rising burden of metabolic diseases, especially among populations spending most of their time indoors.

Seasonal Mortality Patterns Point to Sunlight’s Role

Death rates from heart disease, cancer, stroke, Alzheimer’s, diabetes, and respiratory illness all peak one to three weeks after the shortest day of the year and bottom out after the longest day.

This pattern holds across both infectious and non-infectious causes. The seasonal variation in heart disease deaths alone exceeds total influenza deaths during flu season.

Australia shows the same pattern, but shifted six months—deaths peak in July, their winter. Singapore, 80 miles from the equator with year-round sun, shows no seasonal mortality pattern.

Multiple studies have linked mortality rates to latitude, independent of vitamin D levels, suggesting sunlight itself—particularly its infrared component—plays a direct metabolic role.

Hospitals Are Bringing Patients Outside

Armed with mounting evidence, hospitals worldwide are redesigning care spaces to maximize sunlight exposure.

A $1.5 billion hospital in Footscray, Australia, built ICU beds with direct outdoor access. King’s College Hospital in London invested £2 million to transform its rooftop into a critical care garden where up to six ICU patients can receive treatment surrounded by greenery and natural light.

St. George’s Hospital in London followed suit, creating a neurointensive care rooftop unit. Queen Camilla visited the facility in 2026 to recognize the innovation.

Randomized controlled trials using infrared vests delivering roughly 20–30 watts per square meter (comparable to sitting under a tree) showed 30% reductions in ICU length of stay and improved muscle strength in critically ill COVID-19 patients.

Metabolic Scaling Matches Solar Power Scaling

One of the paper’s most intriguing observations: metabolic rate scales with body mass to the 3/4 power across species from flies to elephants.

Solar power intercepted by an organism also scales to the 3/4 power of mass—nearly identical.

This doesn’t prove causation, but it suggests sunlight could be a universal regulator of metabolic activity across the biosphere, with mitochondria in all organisms tuned to respond to the same infrared wavelengths present in Earth’s solar photon field.

What Makes This Hypothesis Different

Earlier theories proposed infrared light works by activating a photoreceptor in cytochrome c oxidase (complex IV) or by reducing water viscosity around ATP synthase motors.

Seheult’s team doesn’t reject these mechanisms—but argues they’re incomplete.

The Marcus framework explains phenomena earlier models couldn’t: why some infrared wavelengths inhibit rather than enhance mitochondrial activity, why broadband light outperforms monochromatic sources, and why effects persist across vastly different organisms.

The paper is the first to integrate four separate literature streams:

• Mitochondrial electron transfer follows Marcus physics
• Red and near-infrared light alter mitochondrial function
• Water and protein structures affect electron transfer kinetics
• Infrared radiation changes molecular electron transfer rates

“The novelty lies in the mechanistic integration,” Seheult emphasizes, “not in any single component.”

What Comes Next

The hypothesis is testable. Future experiments could measure how different infrared wavelengths alter specific Marcus crossing configurations in isolated mitochondrial complexes, or track real-time changes in reorganization energy using advanced spectroscopy.

If validated, the implications extend far beyond biology. Urban planning, architecture, workplace design, and lighting standards may all need reconsideration.

Seheult introduces a new term: photometabolism—solar-driven, non-photosynthetic modulation of core metabolic processes.

It’s a concept that positions sunlight not as a passive environmental factor, but as an active participant in the biochemistry of life itself.

I believe that this hypothesis if true has major implications for the built environment and how we live and the type of light that we require to live, and I believe it’s one of the major reasons why we need to be treating our patients outside.

Sources

• Jeffery et al. (2025) – Longer wavelengths in sunlight penetrating human tissue
• Ma et al. (2018) – Infrared perturbation of charge separation and recombination
• Sanderson et al. (2018) – Inhibitory modulation of cytochrome c oxidase with near-infrared wavelengths
• Dai et al. (2026) – Infrared stimulation of mitochondrial metabolism in deep-sea yeast
• Hayashi et al. (2010) – Water-mediated electron transfer in iron-sulfur bridges
• Marcus and Sutin (1985) – Electron transfer reactions in chemistry

The Core Hypothesis: Sunlight Tunes Mitochondrial Machinery

Seheult and his collaborators propose that infrared light from the sun acts as a metabolic modulator by influencing how efficiently electrons move through the mitochondrial electron transport chain.

“Electrons move best when the surrounding molecules are arranged just right,” Seheult explains. “Infrared light causes those molecules to vibrate, changing how often the mitochondria reach those favorable arrangements.”

Unlike previous theories that focused on a single photoreceptor in one mitochondrial protein, this new framework suggests infrared light works across multiple pathways simultaneously by altering the vibrational energy of proteins, water, and lipids that surround electron transfer sites.

Why Sunlight Penetrates Deeper Than You Think

Most people assume sunlight only affects the skin surface. But research published in 2025 by Dr. Glenn Jeffery’s group demonstrated that longer wavelengths of infrared light can pass completely through human tissue.

Light is able to go through the body. It is able to be absorbed and it is doing stuff in the body.

In one striking experiment, 850-nanometer light was shown passing through a human hand with measurable intensity on the other side. Infrared wavelengths between 750 and 1,000 nanometers can even penetrate clothing.

This discovery opens the door to a startling possibility: infrared photons from the sun may be reaching mitochondria deep inside the body and influencing their activity in real time.

The Sun’s Special Infrared Signature

Not all light sources are created equal. The sun emits a broad spectrum of infrared wavelengths, but one particular photon energy—0.754 electron volts—is especially abundant.

This peak occurs because of the sun’s photosphere, a layer rich in negatively charged hydrogen atoms called hydride ions. These ions absorb higher-energy photons and re-emit them at exactly 0.754 electron volts.

Seheult likens it to dollar bills falling from the sky. While visible light carries the most total energy (like $100 bills), infrared photons are the most numerous (like $1 bills).

The result? A unique atmospheric window that allows these photons to reach Earth’s surface in abundance—and potentially interact with living cells in ways artificial light cannot replicate.

Marcus Electron Transfer: The Physics Behind the Biology

To understand how infrared light affects mitochondria, Seheult’s team turned to Marcus electron transfer theory, pioneered by Nobel laureate Rudolph Marcus in the 1960s.

Electrons don’t jump spontaneously between molecules. They require surrounding proteins, water, and lipids to twist into precise configurations—a process that demands energy called “reorganization energy.”

When infrared light hits these structures, it causes them to vibrate. This shifts the probability that molecules will be in the right arrangement for electron transfer to occur.

• If the crossing point is already accessible: Infrared light can push molecules away from optimal configurations, slowing electron transfer
• If the crossing point requires activation: Infrared light can push molecules toward optimal configurations, speeding electron transfer

This explains a puzzling finding from earlier studies: different infrared wavelengths can either increase or decrease mitochondrial activity.

Experiments Confirm the Mechanism

A 2018 study by Ma and colleagues tested this exact principle. Researchers built a custom molecule and used mid-infrared light to excite vibrational modes.

They found infrared light slowed forward electron transfer but accelerated backward transfer—precisely what Marcus theory predicts when nuclear orientations are shifted along energy curves.

IR excitation increases the probability of donor and acceptor energies to remain in degeneracy, resulting in IR-induced electron transfer rate enhancement.

Seheult notes he and co-author Dr. Robert Fosbury spoke with Marcus himself—just months before the scientist passed away at age 102—to discuss their hypothesis.

Deep-Sea Yeast Thrives on Infrared Light—Without Photosynthesis

Perhaps the most striking evidence comes from an unexpected source: yeast living near hydrothermal vents at the bottom of the ocean.

A 2026 study by Dai and colleagues isolated yeast from sediments near a “black smoker” chimney in the central Indian Ocean, more than half a meter from superheated mineral plumes reaching 378°C.

When researchers exposed these yeast cultures to near-infrared light (810–1050 nm) in temperature-controlled conditions, growth increased dramatically compared to dark controls—even though the yeast cannot photosynthesize.

Infrared light outperformed glucose. Adding glucose increased biomass by only 1.3-fold (not statistically significant), while 880-nanometer infrared light produced a threefold increase.

When researchers blocked cytochrome c oxidase (complex IV in mitochondria), near-infrared-stimulated growth dropped by 44%—suggesting the effect operates directly on mitochondrial machinery.

Cold Temperatures, Warm Light

Even more remarkable: infrared light allowed yeast to grow at cooler temperatures where dark controls remained dormant.

At 20°C, yeast exposed to 880-nanometer light grew vigorously while dark controls showed minimal activity. The effective activation energy dropped from 12 kilocalories per mole to just 2 kilocalories per mole.

Infrared light was making up for the cold temperatures by supplying vibrational activation rather than thermal activation.

Proteomics revealed the most upregulated protein after infrared exposure was a mitochondrial ribosomal protein (MRPs8), increased 6.7-fold.

Why Broadband Sunlight May Beat Monochromatic LEDs

Clinical studies using single-wavelength infrared devices have shown benefits—from reducing ICU length of stay to improving muscle strength in COVID-19 patients.

But Seheult’s hypothesis suggests broadband infrared from the sun may be even more effective.

“Sunlight contains a broad spectrum of wavelengths that can interact with many different vibrational modes and electron transfer steps,” he explains, “rather than targeting only one narrow pathway.”

Research from Jeffery’s lab supports this. When comparing monochromatic 850-nanometer light to a 60-watt incandescent bulb (which emits broad-spectrum infrared), the incandescent bulb produced greater improvements in color blindness.

• Monochromatic 850 nm: 9% improvement (head and body), 5% (body only)
• 60W incandescent bulb: 28% improvement, sustained for weeks

The research here aligns with the hypothesis, though direct mechanistic proof in human mitochondria remains to be demonstrated.

The Modern Indoor Environment: A Metabolic Desert?

LED bulbs emit virtually no infrared radiation. Low-emissivity (Low-E) glass windows, designed to improve energy efficiency, block infrared wavelengths.

Seheult measured infrared exposure in his own dining room with windows open: 0.8 watts per square meter.

Step outside under a shade tree with grass reflecting sunlight? 41.9 watts per square meter—more than 50 times higher.

We have set up a situation where outdoors we’re getting plenty of infrared light, versus being indoors where we have Low-E glass blocking it and LED bulbs producing none.

This raises profound questions about whether chronic infrared deficiency could contribute to the rising burden of metabolic diseases, especially among populations spending most of their time indoors.

Seasonal Mortality Patterns Point to Sunlight’s Role

Death rates from heart disease, cancer, stroke, Alzheimer’s, diabetes, and respiratory illness all peak one to three weeks after the shortest day of the year and bottom out after the longest day.

This pattern holds across both infectious and non-infectious causes. The seasonal variation in heart disease deaths alone exceeds total influenza deaths during flu season.

Australia shows the same pattern, but shifted six months—deaths peak in July, their winter. Singapore, 80 miles from the equator with year-round sun, shows no seasonal mortality pattern.

Multiple studies have linked mortality rates to latitude, independent of vitamin D levels, suggesting sunlight itself—particularly its infrared component—plays a direct metabolic role.

Hospitals Are Bringing Patients Outside

Armed with mounting evidence, hospitals worldwide are redesigning care spaces to maximize sunlight exposure.

A $1.5 billion hospital in Footscray, Australia, built ICU beds with direct outdoor access. King’s College Hospital in London invested £2 million to transform its rooftop into a critical care garden where up to six ICU patients can receive treatment surrounded by greenery and natural light.

St. George’s Hospital in London followed suit, creating a neurointensive care rooftop unit. Queen Camilla visited the facility in 2026 to recognize the innovation.

Randomized controlled trials using infrared vests delivering roughly 20–30 watts per square meter (comparable to sitting under a tree) showed 30% reductions in ICU length of stay and improved muscle strength in critically ill COVID-19 patients.

Metabolic Scaling Matches Solar Power Scaling

One of the paper’s most intriguing observations: metabolic rate scales with body mass to the 3/4 power across species from flies to elephants.

Solar power intercepted by an organism also scales to the 3/4 power of mass—nearly identical.

This doesn’t prove causation, but it suggests sunlight could be a universal regulator of metabolic activity across the biosphere, with mitochondria in all organisms tuned to respond to the same infrared wavelengths present in Earth’s solar photon field.

What Makes This Hypothesis Different

Earlier theories proposed infrared light works by activating a photoreceptor in cytochrome c oxidase (complex IV) or by reducing water viscosity around ATP synthase motors.

Seheult’s team doesn’t reject these mechanisms—but argues they’re incomplete.

The Marcus framework explains phenomena earlier models couldn’t: why some infrared wavelengths inhibit rather than enhance mitochondrial activity, why broadband light outperforms monochromatic sources, and why effects persist across vastly different organisms.

The paper is the first to integrate four separate literature streams:

• Mitochondrial electron transfer follows Marcus physics
• Red and near-infrared light alter mitochondrial function
• Water and protein structures affect electron transfer kinetics
• Infrared radiation changes molecular electron transfer rates

“The novelty lies in the mechanistic integration,” Seheult emphasizes, “not in any single component.”

What Comes Next

The hypothesis is testable. Future experiments could measure how different infrared wavelengths alter specific Marcus crossing configurations in isolated mitochondrial complexes, or track real-time changes in reorganization energy using advanced spectroscopy.

If validated, the implications extend far beyond biology. Urban planning, architecture, workplace design, and lighting standards may all need reconsideration.

Seheult introduces a new term: photometabolism—solar-driven, non-photosynthetic modulation of core metabolic processes.

It’s a concept that positions sunlight not as a passive environmental factor, but as an active participant in the biochemistry of life itself.

I believe that this hypothesis if true has major implications for the built environment and how we live and the type of light that we require to live, and I believe it’s one of the major reasons why we need to be treating our patients outside.

Sources

• Jeffery et al. (2025) – Longer wavelengths in sunlight penetrating human tissue
• Ma et al. (2018) – Infrared perturbation of charge separation and recombination
• Sanderson et al. (2018) – Inhibitory modulation of cytochrome c oxidase with near-infrared wavelengths
• Dai et al. (2026) – Infrared stimulation of mitochondrial metabolism in deep-sea yeast
• Hayashi et al. (2010) – Water-mediated electron transfer in iron-sulfur bridges
• Marcus and Sutin (1985) – Electron transfer reactions in chemistry

The Core Hypothesis: Sunlight Tunes Mitochondrial Machinery

Seheult and his collaborators propose that infrared light from the sun acts as a metabolic modulator by influencing how efficiently electrons move through the mitochondrial electron transport chain.

“Electrons move best when the surrounding molecules are arranged just right,” Seheult explains. “Infrared light causes those molecules to vibrate, changing how often the mitochondria reach those favorable arrangements.”

Unlike previous theories that focused on a single photoreceptor in one mitochondrial protein, this new framework suggests infrared light works across multiple pathways simultaneously by altering the vibrational energy of proteins, water, and lipids that surround electron transfer sites.

Why Sunlight Penetrates Deeper Than You Think

Most people assume sunlight only affects the skin surface. But research published in 2025 by Dr. Glenn Jeffery’s group demonstrated that longer wavelengths of infrared light can pass completely through human tissue.

Light is able to go through the body. It is able to be absorbed and it is doing stuff in the body.

In one striking experiment, 850-nanometer light was shown passing through a human hand with measurable intensity on the other side. Infrared wavelengths between 750 and 1,000 nanometers can even penetrate clothing.

This discovery opens the door to a startling possibility: infrared photons from the sun may be reaching mitochondria deep inside the body and influencing their activity in real time.

The Sun’s Special Infrared Signature

Not all light sources are created equal. The sun emits a broad spectrum of infrared wavelengths, but one particular photon energy—0.754 electron volts—is especially abundant.

This peak occurs because of the sun’s photosphere, a layer rich in negatively charged hydrogen atoms called hydride ions. These ions absorb higher-energy photons and re-emit them at exactly 0.754 electron volts.

Seheult likens it to dollar bills falling from the sky. While visible light carries the most total energy (like $100 bills), infrared photons are the most numerous (like $1 bills).

The result? A unique atmospheric window that allows these photons to reach Earth’s surface in abundance—and potentially interact with living cells in ways artificial light cannot replicate.

Marcus Electron Transfer: The Physics Behind the Biology

To understand how infrared light affects mitochondria, Seheult’s team turned to Marcus electron transfer theory, pioneered by Nobel laureate Rudolph Marcus in the 1960s.

Electrons don’t jump spontaneously between molecules. They require surrounding proteins, water, and lipids to twist into precise configurations—a process that demands energy called “reorganization energy.”

When infrared light hits these structures, it causes them to vibrate. This shifts the probability that molecules will be in the right arrangement for electron transfer to occur.

• If the crossing point is already accessible: Infrared light can push molecules away from optimal configurations, slowing electron transfer
• If the crossing point requires activation: Infrared light can push molecules toward optimal configurations, speeding electron transfer

This explains a puzzling finding from earlier studies: different infrared wavelengths can either increase or decrease mitochondrial activity.

Experiments Confirm the Mechanism

A 2018 study by Ma and colleagues tested this exact principle. Researchers built a custom molecule and used mid-infrared light to excite vibrational modes.

They found infrared light slowed forward electron transfer but accelerated backward transfer—precisely what Marcus theory predicts when nuclear orientations are shifted along energy curves.

IR excitation increases the probability of donor and acceptor energies to remain in degeneracy, resulting in IR-induced electron transfer rate enhancement.

Seheult notes he and co-author Dr. Robert Fosbury spoke with Marcus himself—just months before the scientist passed away at age 102—to discuss their hypothesis.

Deep-Sea Yeast Thrives on Infrared Light—Without Photosynthesis

Perhaps the most striking evidence comes from an unexpected source: yeast living near hydrothermal vents at the bottom of the ocean.

A 2026 study by Dai and colleagues isolated yeast from sediments near a “black smoker” chimney in the central Indian Ocean, more than half a meter from superheated mineral plumes reaching 378°C.

When researchers exposed these yeast cultures to near-infrared light (810–1050 nm) in temperature-controlled conditions, growth increased dramatically compared to dark controls—even though the yeast cannot photosynthesize.

Infrared light outperformed glucose. Adding glucose increased biomass by only 1.3-fold (not statistically significant), while 880-nanometer infrared light produced a threefold increase.

When researchers blocked cytochrome c oxidase (complex IV in mitochondria), near-infrared-stimulated growth dropped by 44%—suggesting the effect operates directly on mitochondrial machinery.

Cold Temperatures, Warm Light

Even more remarkable: infrared light allowed yeast to grow at cooler temperatures where dark controls remained dormant.

At 20°C, yeast exposed to 880-nanometer light grew vigorously while dark controls showed minimal activity. The effective activation energy dropped from 12 kilocalories per mole to just 2 kilocalories per mole.

Infrared light was making up for the cold temperatures by supplying vibrational activation rather than thermal activation.

Proteomics revealed the most upregulated protein after infrared exposure was a mitochondrial ribosomal protein (MRPs8), increased 6.7-fold.

Why Broadband Sunlight May Beat Monochromatic LEDs

Clinical studies using single-wavelength infrared devices have shown benefits—from reducing ICU length of stay to improving muscle strength in COVID-19 patients.

But Seheult’s hypothesis suggests broadband infrared from the sun may be even more effective.

“Sunlight contains a broad spectrum of wavelengths that can interact with many different vibrational modes and electron transfer steps,” he explains, “rather than targeting only one narrow pathway.”

Research from Jeffery’s lab supports this. When comparing monochromatic 850-nanometer light to a 60-watt incandescent bulb (which emits broad-spectrum infrared), the incandescent bulb produced greater improvements in color blindness.

• Monochromatic 850 nm: 9% improvement (head and body), 5% (body only)
• 60W incandescent bulb: 28% improvement, sustained for weeks

The research here aligns with the hypothesis, though direct mechanistic proof in human mitochondria remains to be demonstrated.

The Modern Indoor Environment: A Metabolic Desert?

LED bulbs emit virtually no infrared radiation. Low-emissivity (Low-E) glass windows, designed to improve energy efficiency, block infrared wavelengths.

Seheult measured infrared exposure in his own dining room with windows open: 0.8 watts per square meter.

Step outside under a shade tree with grass reflecting sunlight? 41.9 watts per square meter—more than 50 times higher.

We have set up a situation where outdoors we’re getting plenty of infrared light, versus being indoors where we have Low-E glass blocking it and LED bulbs producing none.

This raises profound questions about whether chronic infrared deficiency could contribute to the rising burden of metabolic diseases, especially among populations spending most of their time indoors.

Seasonal Mortality Patterns Point to Sunlight’s Role

Death rates from heart disease, cancer, stroke, Alzheimer’s, diabetes, and respiratory illness all peak one to three weeks after the shortest day of the year and bottom out after the longest day.

This pattern holds across both infectious and non-infectious causes. The seasonal variation in heart disease deaths alone exceeds total influenza deaths during flu season.

Australia shows the same pattern, but shifted six months—deaths peak in July, their winter. Singapore, 80 miles from the equator with year-round sun, shows no seasonal mortality pattern.

Multiple studies have linked mortality rates to latitude, independent of vitamin D levels, suggesting sunlight itself—particularly its infrared component—plays a direct metabolic role.

Hospitals Are Bringing Patients Outside

Armed with mounting evidence, hospitals worldwide are redesigning care spaces to maximize sunlight exposure.

A $1.5 billion hospital in Footscray, Australia, built ICU beds with direct outdoor access. King’s College Hospital in London invested £2 million to transform its rooftop into a critical care garden where up to six ICU patients can receive treatment surrounded by greenery and natural light.

St. George’s Hospital in London followed suit, creating a neurointensive care rooftop unit. Queen Camilla visited the facility in 2026 to recognize the innovation.

Randomized controlled trials using infrared vests delivering roughly 20–30 watts per square meter (comparable to sitting under a tree) showed 30% reductions in ICU length of stay and improved muscle strength in critically ill COVID-19 patients.

Metabolic Scaling Matches Solar Power Scaling

One of the paper’s most intriguing observations: metabolic rate scales with body mass to the 3/4 power across species from flies to elephants.

Solar power intercepted by an organism also scales to the 3/4 power of mass—nearly identical.

This doesn’t prove causation, but it suggests sunlight could be a universal regulator of metabolic activity across the biosphere, with mitochondria in all organisms tuned to respond to the same infrared wavelengths present in Earth’s solar photon field.

What Makes This Hypothesis Different

Earlier theories proposed infrared light works by activating a photoreceptor in cytochrome c oxidase (complex IV) or by reducing water viscosity around ATP synthase motors.

Seheult’s team doesn’t reject these mechanisms—but argues they’re incomplete.

The Marcus framework explains phenomena earlier models couldn’t: why some infrared wavelengths inhibit rather than enhance mitochondrial activity, why broadband light outperforms monochromatic sources, and why effects persist across vastly different organisms.

The paper is the first to integrate four separate literature streams:

• Mitochondrial electron transfer follows Marcus physics
• Red and near-infrared light alter mitochondrial function
• Water and protein structures affect electron transfer kinetics
• Infrared radiation changes molecular electron transfer rates

“The novelty lies in the mechanistic integration,” Seheult emphasizes, “not in any single component.”

What Comes Next

The hypothesis is testable. Future experiments could measure how different infrared wavelengths alter specific Marcus crossing configurations in isolated mitochondrial complexes, or track real-time changes in reorganization energy using advanced spectroscopy.

If validated, the implications extend far beyond biology. Urban planning, architecture, workplace design, and lighting standards may all need reconsideration.

Seheult introduces a new term: photometabolism—solar-driven, non-photosynthetic modulation of core metabolic processes.

It’s a concept that positions sunlight not as a passive environmental factor, but as an active participant in the biochemistry of life itself.

I believe that this hypothesis if true has major implications for the built environment and how we live and the type of light that we require to live, and I believe it’s one of the major reasons why we need to be treating our patients outside.

Sources

• Jeffery et al. (2025) – Longer wavelengths in sunlight penetrating human tissue
• Ma et al. (2018) – Infrared perturbation of charge separation and recombination
• Sanderson et al. (2018) – Inhibitory modulation of cytochrome c oxidase with near-infrared wavelengths
• Dai et al. (2026) – Infrared stimulation of mitochondrial metabolism in deep-sea yeast
• Hayashi et al. (2010) – Water-mediated electron transfer in iron-sulfur bridges
• Marcus and Sutin (1985) – Electron transfer reactions in chemistry

If the hypothesis holds, it suggests our modern indoor environments—filled with LED lighting and low-E glass windows that block infrared—may be quietly undermining our metabolic health.

The Core Hypothesis: Sunlight Tunes Mitochondrial Machinery

Seheult and his collaborators propose that infrared light from the sun acts as a metabolic modulator by influencing how efficiently electrons move through the mitochondrial electron transport chain.

“Electrons move best when the surrounding molecules are arranged just right,” Seheult explains. “Infrared light causes those molecules to vibrate, changing how often the mitochondria reach those favorable arrangements.”

Unlike previous theories that focused on a single photoreceptor in one mitochondrial protein, this new framework suggests infrared light works across multiple pathways simultaneously by altering the vibrational energy of proteins, water, and lipids that surround electron transfer sites.

Why Sunlight Penetrates Deeper Than You Think

Most people assume sunlight only affects the skin surface. But research published in 2025 by Dr. Glenn Jeffery’s group demonstrated that longer wavelengths of infrared light can pass completely through human tissue.

Light is able to go through the body. It is able to be absorbed and it is doing stuff in the body.

In one striking experiment, 850-nanometer light was shown passing through a human hand with measurable intensity on the other side. Infrared wavelengths between 750 and 1,000 nanometers can even penetrate clothing.

This discovery opens the door to a startling possibility: infrared photons from the sun may be reaching mitochondria deep inside the body and influencing their activity in real time.

The Sun’s Special Infrared Signature

Not all light sources are created equal. The sun emits a broad spectrum of infrared wavelengths, but one particular photon energy—0.754 electron volts—is especially abundant.

This peak occurs because of the sun’s photosphere, a layer rich in negatively charged hydrogen atoms called hydride ions. These ions absorb higher-energy photons and re-emit them at exactly 0.754 electron volts.

Seheult likens it to dollar bills falling from the sky. While visible light carries the most total energy (like $100 bills), infrared photons are the most numerous (like $1 bills).

The result? A unique atmospheric window that allows these photons to reach Earth’s surface in abundance—and potentially interact with living cells in ways artificial light cannot replicate.

Marcus Electron Transfer: The Physics Behind the Biology

To understand how infrared light affects mitochondria, Seheult’s team turned to Marcus electron transfer theory, pioneered by Nobel laureate Rudolph Marcus in the 1960s.

Electrons don’t jump spontaneously between molecules. They require surrounding proteins, water, and lipids to twist into precise configurations—a process that demands energy called “reorganization energy.”

When infrared light hits these structures, it causes them to vibrate. This shifts the probability that molecules will be in the right arrangement for electron transfer to occur.

• If the crossing point is already accessible: Infrared light can push molecules away from optimal configurations, slowing electron transfer
• If the crossing point requires activation: Infrared light can push molecules toward optimal configurations, speeding electron transfer

This explains a puzzling finding from earlier studies: different infrared wavelengths can either increase or decrease mitochondrial activity.

Experiments Confirm the Mechanism

A 2018 study by Ma and colleagues tested this exact principle. Researchers built a custom molecule and used mid-infrared light to excite vibrational modes.

They found infrared light slowed forward electron transfer but accelerated backward transfer—precisely what Marcus theory predicts when nuclear orientations are shifted along energy curves.

IR excitation increases the probability of donor and acceptor energies to remain in degeneracy, resulting in IR-induced electron transfer rate enhancement.

Seheult notes he and co-author Dr. Robert Fosbury spoke with Marcus himself—just months before the scientist passed away at age 102—to discuss their hypothesis.

Deep-Sea Yeast Thrives on Infrared Light—Without Photosynthesis

Perhaps the most striking evidence comes from an unexpected source: yeast living near hydrothermal vents at the bottom of the ocean.

A 2026 study by Dai and colleagues isolated yeast from sediments near a “black smoker” chimney in the central Indian Ocean, more than half a meter from superheated mineral plumes reaching 378°C.

When researchers exposed these yeast cultures to near-infrared light (810–1050 nm) in temperature-controlled conditions, growth increased dramatically compared to dark controls—even though the yeast cannot photosynthesize.

Infrared light outperformed glucose. Adding glucose increased biomass by only 1.3-fold (not statistically significant), while 880-nanometer infrared light produced a threefold increase.

When researchers blocked cytochrome c oxidase (complex IV in mitochondria), near-infrared-stimulated growth dropped by 44%—suggesting the effect operates directly on mitochondrial machinery.

Cold Temperatures, Warm Light

Even more remarkable: infrared light allowed yeast to grow at cooler temperatures where dark controls remained dormant.

At 20°C, yeast exposed to 880-nanometer light grew vigorously while dark controls showed minimal activity. The effective activation energy dropped from 12 kilocalories per mole to just 2 kilocalories per mole.

Infrared light was making up for the cold temperatures by supplying vibrational activation rather than thermal activation.

Proteomics revealed the most upregulated protein after infrared exposure was a mitochondrial ribosomal protein (MRPs8), increased 6.7-fold.

Why Broadband Sunlight May Beat Monochromatic LEDs

Clinical studies using single-wavelength infrared devices have shown benefits—from reducing ICU length of stay to improving muscle strength in COVID-19 patients.

But Seheult’s hypothesis suggests broadband infrared from the sun may be even more effective.

“Sunlight contains a broad spectrum of wavelengths that can interact with many different vibrational modes and electron transfer steps,” he explains, “rather than targeting only one narrow pathway.”

Research from Jeffery’s lab supports this. When comparing monochromatic 850-nanometer light to a 60-watt incandescent bulb (which emits broad-spectrum infrared), the incandescent bulb produced greater improvements in color blindness.

• Monochromatic 850 nm: 9% improvement (head and body), 5% (body only)
• 60W incandescent bulb: 28% improvement, sustained for weeks

The research here aligns with the hypothesis, though direct mechanistic proof in human mitochondria remains to be demonstrated.

The Modern Indoor Environment: A Metabolic Desert?

LED bulbs emit virtually no infrared radiation. Low-emissivity (Low-E) glass windows, designed to improve energy efficiency, block infrared wavelengths.

Seheult measured infrared exposure in his own dining room with windows open: 0.8 watts per square meter.

Step outside under a shade tree with grass reflecting sunlight? 41.9 watts per square meter—more than 50 times higher.

We have set up a situation where outdoors we’re getting plenty of infrared light, versus being indoors where we have Low-E glass blocking it and LED bulbs producing none.

This raises profound questions about whether chronic infrared deficiency could contribute to the rising burden of metabolic diseases, especially among populations spending most of their time indoors.

Seasonal Mortality Patterns Point to Sunlight’s Role

Death rates from heart disease, cancer, stroke, Alzheimer’s, diabetes, and respiratory illness all peak one to three weeks after the shortest day of the year and bottom out after the longest day.

This pattern holds across both infectious and non-infectious causes. The seasonal variation in heart disease deaths alone exceeds total influenza deaths during flu season.

Australia shows the same pattern, but shifted six months—deaths peak in July, their winter. Singapore, 80 miles from the equator with year-round sun, shows no seasonal mortality pattern.

Multiple studies have linked mortality rates to latitude, independent of vitamin D levels, suggesting sunlight itself—particularly its infrared component—plays a direct metabolic role.

Hospitals Are Bringing Patients Outside

Armed with mounting evidence, hospitals worldwide are redesigning care spaces to maximize sunlight exposure.

A $1.5 billion hospital in Footscray, Australia, built ICU beds with direct outdoor access. King’s College Hospital in London invested £2 million to transform its rooftop into a critical care garden where up to six ICU patients can receive treatment surrounded by greenery and natural light.

St. George’s Hospital in London followed suit, creating a neurointensive care rooftop unit. Queen Camilla visited the facility in 2026 to recognize the innovation.

Randomized controlled trials using infrared vests delivering roughly 20–30 watts per square meter (comparable to sitting under a tree) showed 30% reductions in ICU length of stay and improved muscle strength in critically ill COVID-19 patients.

Metabolic Scaling Matches Solar Power Scaling

One of the paper’s most intriguing observations: metabolic rate scales with body mass to the 3/4 power across species from flies to elephants.

Solar power intercepted by an organism also scales to the 3/4 power of mass—nearly identical.

This doesn’t prove causation, but it suggests sunlight could be a universal regulator of metabolic activity across the biosphere, with mitochondria in all organisms tuned to respond to the same infrared wavelengths present in Earth’s solar photon field.

What Makes This Hypothesis Different

Earlier theories proposed infrared light works by activating a photoreceptor in cytochrome c oxidase (complex IV) or by reducing water viscosity around ATP synthase motors.

Seheult’s team doesn’t reject these mechanisms—but argues they’re incomplete.

The Marcus framework explains phenomena earlier models couldn’t: why some infrared wavelengths inhibit rather than enhance mitochondrial activity, why broadband light outperforms monochromatic sources, and why effects persist across vastly different organisms.

The paper is the first to integrate four separate literature streams:

• Mitochondrial electron transfer follows Marcus physics
• Red and near-infrared light alter mitochondrial function
• Water and protein structures affect electron transfer kinetics
• Infrared radiation changes molecular electron transfer rates

“The novelty lies in the mechanistic integration,” Seheult emphasizes, “not in any single component.”

What Comes Next

The hypothesis is testable. Future experiments could measure how different infrared wavelengths alter specific Marcus crossing configurations in isolated mitochondrial complexes, or track real-time changes in reorganization energy using advanced spectroscopy.

If validated, the implications extend far beyond biology. Urban planning, architecture, workplace design, and lighting standards may all need reconsideration.

Seheult introduces a new term: photometabolism—solar-driven, non-photosynthetic modulation of core metabolic processes.

It’s a concept that positions sunlight not as a passive environmental factor, but as an active participant in the biochemistry of life itself.

I believe that this hypothesis if true has major implications for the built environment and how we live and the type of light that we require to live, and I believe it’s one of the major reasons why we need to be treating our patients outside.

Sources

• Jeffery et al. (2025) – Longer wavelengths in sunlight penetrating human tissue
• Ma et al. (2018) – Infrared perturbation of charge separation and recombination
• Sanderson et al. (2018) – Inhibitory modulation of cytochrome c oxidase with near-infrared wavelengths
• Dai et al. (2026) – Infrared stimulation of mitochondrial metabolism in deep-sea yeast
• Hayashi et al. (2010) – Water-mediated electron transfer in iron-sulfur bridges
• Marcus and Sutin (1985) – Electron transfer reactions in chemistry

If the hypothesis holds, it suggests our modern indoor environments—filled with LED lighting and low-E glass windows that block infrared—may be quietly undermining our metabolic health.

The Core Hypothesis: Sunlight Tunes Mitochondrial Machinery

Seheult and his collaborators propose that infrared light from the sun acts as a metabolic modulator by influencing how efficiently electrons move through the mitochondrial electron transport chain.

“Electrons move best when the surrounding molecules are arranged just right,” Seheult explains. “Infrared light causes those molecules to vibrate, changing how often the mitochondria reach those favorable arrangements.”

Unlike previous theories that focused on a single photoreceptor in one mitochondrial protein, this new framework suggests infrared light works across multiple pathways simultaneously by altering the vibrational energy of proteins, water, and lipids that surround electron transfer sites.

Why Sunlight Penetrates Deeper Than You Think

Most people assume sunlight only affects the skin surface. But research published in 2025 by Dr. Glenn Jeffery’s group demonstrated that longer wavelengths of infrared light can pass completely through human tissue.

Light is able to go through the body. It is able to be absorbed and it is doing stuff in the body.

In one striking experiment, 850-nanometer light was shown passing through a human hand with measurable intensity on the other side. Infrared wavelengths between 750 and 1,000 nanometers can even penetrate clothing.

This discovery opens the door to a startling possibility: infrared photons from the sun may be reaching mitochondria deep inside the body and influencing their activity in real time.

The Sun’s Special Infrared Signature

Not all light sources are created equal. The sun emits a broad spectrum of infrared wavelengths, but one particular photon energy—0.754 electron volts—is especially abundant.

This peak occurs because of the sun’s photosphere, a layer rich in negatively charged hydrogen atoms called hydride ions. These ions absorb higher-energy photons and re-emit them at exactly 0.754 electron volts.

Seheult likens it to dollar bills falling from the sky. While visible light carries the most total energy (like $100 bills), infrared photons are the most numerous (like $1 bills).

The result? A unique atmospheric window that allows these photons to reach Earth’s surface in abundance—and potentially interact with living cells in ways artificial light cannot replicate.

Marcus Electron Transfer: The Physics Behind the Biology

To understand how infrared light affects mitochondria, Seheult’s team turned to Marcus electron transfer theory, pioneered by Nobel laureate Rudolph Marcus in the 1960s.

Electrons don’t jump spontaneously between molecules. They require surrounding proteins, water, and lipids to twist into precise configurations—a process that demands energy called “reorganization energy.”

When infrared light hits these structures, it causes them to vibrate. This shifts the probability that molecules will be in the right arrangement for electron transfer to occur.

• If the crossing point is already accessible: Infrared light can push molecules away from optimal configurations, slowing electron transfer
• If the crossing point requires activation: Infrared light can push molecules toward optimal configurations, speeding electron transfer

This explains a puzzling finding from earlier studies: different infrared wavelengths can either increase or decrease mitochondrial activity.

Experiments Confirm the Mechanism

A 2018 study by Ma and colleagues tested this exact principle. Researchers built a custom molecule and used mid-infrared light to excite vibrational modes.

They found infrared light slowed forward electron transfer but accelerated backward transfer—precisely what Marcus theory predicts when nuclear orientations are shifted along energy curves.

IR excitation increases the probability of donor and acceptor energies to remain in degeneracy, resulting in IR-induced electron transfer rate enhancement.

Seheult notes he and co-author Dr. Robert Fosbury spoke with Marcus himself—just months before the scientist passed away at age 102—to discuss their hypothesis.

Deep-Sea Yeast Thrives on Infrared Light—Without Photosynthesis

Perhaps the most striking evidence comes from an unexpected source: yeast living near hydrothermal vents at the bottom of the ocean.

A 2026 study by Dai and colleagues isolated yeast from sediments near a “black smoker” chimney in the central Indian Ocean, more than half a meter from superheated mineral plumes reaching 378°C.

When researchers exposed these yeast cultures to near-infrared light (810–1050 nm) in temperature-controlled conditions, growth increased dramatically compared to dark controls—even though the yeast cannot photosynthesize.

Infrared light outperformed glucose. Adding glucose increased biomass by only 1.3-fold (not statistically significant), while 880-nanometer infrared light produced a threefold increase.

When researchers blocked cytochrome c oxidase (complex IV in mitochondria), near-infrared-stimulated growth dropped by 44%—suggesting the effect operates directly on mitochondrial machinery.

Cold Temperatures, Warm Light

Even more remarkable: infrared light allowed yeast to grow at cooler temperatures where dark controls remained dormant.

At 20°C, yeast exposed to 880-nanometer light grew vigorously while dark controls showed minimal activity. The effective activation energy dropped from 12 kilocalories per mole to just 2 kilocalories per mole.

Infrared light was making up for the cold temperatures by supplying vibrational activation rather than thermal activation.

Proteomics revealed the most upregulated protein after infrared exposure was a mitochondrial ribosomal protein (MRPs8), increased 6.7-fold.

Why Broadband Sunlight May Beat Monochromatic LEDs

Clinical studies using single-wavelength infrared devices have shown benefits—from reducing ICU length of stay to improving muscle strength in COVID-19 patients.

But Seheult’s hypothesis suggests broadband infrared from the sun may be even more effective.

“Sunlight contains a broad spectrum of wavelengths that can interact with many different vibrational modes and electron transfer steps,” he explains, “rather than targeting only one narrow pathway.”

Research from Jeffery’s lab supports this. When comparing monochromatic 850-nanometer light to a 60-watt incandescent bulb (which emits broad-spectrum infrared), the incandescent bulb produced greater improvements in color blindness.

• Monochromatic 850 nm: 9% improvement (head and body), 5% (body only)
• 60W incandescent bulb: 28% improvement, sustained for weeks

The research here aligns with the hypothesis, though direct mechanistic proof in human mitochondria remains to be demonstrated.

The Modern Indoor Environment: A Metabolic Desert?

LED bulbs emit virtually no infrared radiation. Low-emissivity (Low-E) glass windows, designed to improve energy efficiency, block infrared wavelengths.

Seheult measured infrared exposure in his own dining room with windows open: 0.8 watts per square meter.

Step outside under a shade tree with grass reflecting sunlight? 41.9 watts per square meter—more than 50 times higher.

We have set up a situation where outdoors we’re getting plenty of infrared light, versus being indoors where we have Low-E glass blocking it and LED bulbs producing none.

This raises profound questions about whether chronic infrared deficiency could contribute to the rising burden of metabolic diseases, especially among populations spending most of their time indoors.

Seasonal Mortality Patterns Point to Sunlight’s Role

Death rates from heart disease, cancer, stroke, Alzheimer’s, diabetes, and respiratory illness all peak one to three weeks after the shortest day of the year and bottom out after the longest day.

This pattern holds across both infectious and non-infectious causes. The seasonal variation in heart disease deaths alone exceeds total influenza deaths during flu season.

Australia shows the same pattern, but shifted six months—deaths peak in July, their winter. Singapore, 80 miles from the equator with year-round sun, shows no seasonal mortality pattern.

Multiple studies have linked mortality rates to latitude, independent of vitamin D levels, suggesting sunlight itself—particularly its infrared component—plays a direct metabolic role.

Hospitals Are Bringing Patients Outside

Armed with mounting evidence, hospitals worldwide are redesigning care spaces to maximize sunlight exposure.

A $1.5 billion hospital in Footscray, Australia, built ICU beds with direct outdoor access. King’s College Hospital in London invested £2 million to transform its rooftop into a critical care garden where up to six ICU patients can receive treatment surrounded by greenery and natural light.

St. George’s Hospital in London followed suit, creating a neurointensive care rooftop unit. Queen Camilla visited the facility in 2026 to recognize the innovation.

Randomized controlled trials using infrared vests delivering roughly 20–30 watts per square meter (comparable to sitting under a tree) showed 30% reductions in ICU length of stay and improved muscle strength in critically ill COVID-19 patients.

Metabolic Scaling Matches Solar Power Scaling

One of the paper’s most intriguing observations: metabolic rate scales with body mass to the 3/4 power across species from flies to elephants.

Solar power intercepted by an organism also scales to the 3/4 power of mass—nearly identical.

This doesn’t prove causation, but it suggests sunlight could be a universal regulator of metabolic activity across the biosphere, with mitochondria in all organisms tuned to respond to the same infrared wavelengths present in Earth’s solar photon field.

What Makes This Hypothesis Different

Earlier theories proposed infrared light works by activating a photoreceptor in cytochrome c oxidase (complex IV) or by reducing water viscosity around ATP synthase motors.

Seheult’s team doesn’t reject these mechanisms—but argues they’re incomplete.

The Marcus framework explains phenomena earlier models couldn’t: why some infrared wavelengths inhibit rather than enhance mitochondrial activity, why broadband light outperforms monochromatic sources, and why effects persist across vastly different organisms.

The paper is the first to integrate four separate literature streams:

• Mitochondrial electron transfer follows Marcus physics
• Red and near-infrared light alter mitochondrial function
• Water and protein structures affect electron transfer kinetics
• Infrared radiation changes molecular electron transfer rates

“The novelty lies in the mechanistic integration,” Seheult emphasizes, “not in any single component.”

What Comes Next

The hypothesis is testable. Future experiments could measure how different infrared wavelengths alter specific Marcus crossing configurations in isolated mitochondrial complexes, or track real-time changes in reorganization energy using advanced spectroscopy.

If validated, the implications extend far beyond biology. Urban planning, architecture, workplace design, and lighting standards may all need reconsideration.

Seheult introduces a new term: photometabolism—solar-driven, non-photosynthetic modulation of core metabolic processes.

It’s a concept that positions sunlight not as a passive environmental factor, but as an active participant in the biochemistry of life itself.

I believe that this hypothesis if true has major implications for the built environment and how we live and the type of light that we require to live, and I believe it’s one of the major reasons why we need to be treating our patients outside.

Sources

• Jeffery et al. (2025) – Longer wavelengths in sunlight penetrating human tissue
• Ma et al. (2018) – Infrared perturbation of charge separation and recombination
• Sanderson et al. (2018) – Inhibitory modulation of cytochrome c oxidase with near-infrared wavelengths
• Dai et al. (2026) – Infrared stimulation of mitochondrial metabolism in deep-sea yeast
• Hayashi et al. (2010) – Water-mediated electron transfer in iron-sulfur bridges
• Marcus and Sutin (1985) – Electron transfer reactions in chemistry

The work brings together experts from astrophysics, neuroscience, lighting engineering, and medicine to explain why sunlight may be far more than just a source of vitamin D.

If the hypothesis holds, it suggests our modern indoor environments—filled with LED lighting and low-E glass windows that block infrared—may be quietly undermining our metabolic health.

The Core Hypothesis: Sunlight Tunes Mitochondrial Machinery

Seheult and his collaborators propose that infrared light from the sun acts as a metabolic modulator by influencing how efficiently electrons move through the mitochondrial electron transport chain.

“Electrons move best when the surrounding molecules are arranged just right,” Seheult explains. “Infrared light causes those molecules to vibrate, changing how often the mitochondria reach those favorable arrangements.”

Unlike previous theories that focused on a single photoreceptor in one mitochondrial protein, this new framework suggests infrared light works across multiple pathways simultaneously by altering the vibrational energy of proteins, water, and lipids that surround electron transfer sites.

Why Sunlight Penetrates Deeper Than You Think

Most people assume sunlight only affects the skin surface. But research published in 2025 by Dr. Glenn Jeffery’s group demonstrated that longer wavelengths of infrared light can pass completely through human tissue.

Light is able to go through the body. It is able to be absorbed and it is doing stuff in the body.

In one striking experiment, 850-nanometer light was shown passing through a human hand with measurable intensity on the other side. Infrared wavelengths between 750 and 1,000 nanometers can even penetrate clothing.

This discovery opens the door to a startling possibility: infrared photons from the sun may be reaching mitochondria deep inside the body and influencing their activity in real time.

The Sun’s Special Infrared Signature

Not all light sources are created equal. The sun emits a broad spectrum of infrared wavelengths, but one particular photon energy—0.754 electron volts—is especially abundant.

This peak occurs because of the sun’s photosphere, a layer rich in negatively charged hydrogen atoms called hydride ions. These ions absorb higher-energy photons and re-emit them at exactly 0.754 electron volts.

Seheult likens it to dollar bills falling from the sky. While visible light carries the most total energy (like $100 bills), infrared photons are the most numerous (like $1 bills).

The result? A unique atmospheric window that allows these photons to reach Earth’s surface in abundance—and potentially interact with living cells in ways artificial light cannot replicate.

Marcus Electron Transfer: The Physics Behind the Biology

To understand how infrared light affects mitochondria, Seheult’s team turned to Marcus electron transfer theory, pioneered by Nobel laureate Rudolph Marcus in the 1960s.

Electrons don’t jump spontaneously between molecules. They require surrounding proteins, water, and lipids to twist into precise configurations—a process that demands energy called “reorganization energy.”

When infrared light hits these structures, it causes them to vibrate. This shifts the probability that molecules will be in the right arrangement for electron transfer to occur.

• If the crossing point is already accessible: Infrared light can push molecules away from optimal configurations, slowing electron transfer
• If the crossing point requires activation: Infrared light can push molecules toward optimal configurations, speeding electron transfer

This explains a puzzling finding from earlier studies: different infrared wavelengths can either increase or decrease mitochondrial activity.

Experiments Confirm the Mechanism

A 2018 study by Ma and colleagues tested this exact principle. Researchers built a custom molecule and used mid-infrared light to excite vibrational modes.

They found infrared light slowed forward electron transfer but accelerated backward transfer—precisely what Marcus theory predicts when nuclear orientations are shifted along energy curves.

IR excitation increases the probability of donor and acceptor energies to remain in degeneracy, resulting in IR-induced electron transfer rate enhancement.

Seheult notes he and co-author Dr. Robert Fosbury spoke with Marcus himself—just months before the scientist passed away at age 102—to discuss their hypothesis.

Deep-Sea Yeast Thrives on Infrared Light—Without Photosynthesis

Perhaps the most striking evidence comes from an unexpected source: yeast living near hydrothermal vents at the bottom of the ocean.

A 2026 study by Dai and colleagues isolated yeast from sediments near a “black smoker” chimney in the central Indian Ocean, more than half a meter from superheated mineral plumes reaching 378°C.

When researchers exposed these yeast cultures to near-infrared light (810–1050 nm) in temperature-controlled conditions, growth increased dramatically compared to dark controls—even though the yeast cannot photosynthesize.

Infrared light outperformed glucose. Adding glucose increased biomass by only 1.3-fold (not statistically significant), while 880-nanometer infrared light produced a threefold increase.

When researchers blocked cytochrome c oxidase (complex IV in mitochondria), near-infrared-stimulated growth dropped by 44%—suggesting the effect operates directly on mitochondrial machinery.

Cold Temperatures, Warm Light

Even more remarkable: infrared light allowed yeast to grow at cooler temperatures where dark controls remained dormant.

At 20°C, yeast exposed to 880-nanometer light grew vigorously while dark controls showed minimal activity. The effective activation energy dropped from 12 kilocalories per mole to just 2 kilocalories per mole.

Infrared light was making up for the cold temperatures by supplying vibrational activation rather than thermal activation.

Proteomics revealed the most upregulated protein after infrared exposure was a mitochondrial ribosomal protein (MRPs8), increased 6.7-fold.

Why Broadband Sunlight May Beat Monochromatic LEDs

Clinical studies using single-wavelength infrared devices have shown benefits—from reducing ICU length of stay to improving muscle strength in COVID-19 patients.

But Seheult’s hypothesis suggests broadband infrared from the sun may be even more effective.

“Sunlight contains a broad spectrum of wavelengths that can interact with many different vibrational modes and electron transfer steps,” he explains, “rather than targeting only one narrow pathway.”

Research from Jeffery’s lab supports this. When comparing monochromatic 850-nanometer light to a 60-watt incandescent bulb (which emits broad-spectrum infrared), the incandescent bulb produced greater improvements in color blindness.

• Monochromatic 850 nm: 9% improvement (head and body), 5% (body only)
• 60W incandescent bulb: 28% improvement, sustained for weeks

The research here aligns with the hypothesis, though direct mechanistic proof in human mitochondria remains to be demonstrated.

The Modern Indoor Environment: A Metabolic Desert?

LED bulbs emit virtually no infrared radiation. Low-emissivity (Low-E) glass windows, designed to improve energy efficiency, block infrared wavelengths.

Seheult measured infrared exposure in his own dining room with windows open: 0.8 watts per square meter.

Step outside under a shade tree with grass reflecting sunlight? 41.9 watts per square meter—more than 50 times higher.

We have set up a situation where outdoors we’re getting plenty of infrared light, versus being indoors where we have Low-E glass blocking it and LED bulbs producing none.

This raises profound questions about whether chronic infrared deficiency could contribute to the rising burden of metabolic diseases, especially among populations spending most of their time indoors.

Seasonal Mortality Patterns Point to Sunlight’s Role

Death rates from heart disease, cancer, stroke, Alzheimer’s, diabetes, and respiratory illness all peak one to three weeks after the shortest day of the year and bottom out after the longest day.

This pattern holds across both infectious and non-infectious causes. The seasonal variation in heart disease deaths alone exceeds total influenza deaths during flu season.

Australia shows the same pattern, but shifted six months—deaths peak in July, their winter. Singapore, 80 miles from the equator with year-round sun, shows no seasonal mortality pattern.

Multiple studies have linked mortality rates to latitude, independent of vitamin D levels, suggesting sunlight itself—particularly its infrared component—plays a direct metabolic role.

Hospitals Are Bringing Patients Outside

Armed with mounting evidence, hospitals worldwide are redesigning care spaces to maximize sunlight exposure.

A $1.5 billion hospital in Footscray, Australia, built ICU beds with direct outdoor access. King’s College Hospital in London invested £2 million to transform its rooftop into a critical care garden where up to six ICU patients can receive treatment surrounded by greenery and natural light.

St. George’s Hospital in London followed suit, creating a neurointensive care rooftop unit. Queen Camilla visited the facility in 2026 to recognize the innovation.

Randomized controlled trials using infrared vests delivering roughly 20–30 watts per square meter (comparable to sitting under a tree) showed 30% reductions in ICU length of stay and improved muscle strength in critically ill COVID-19 patients.

Metabolic Scaling Matches Solar Power Scaling

One of the paper’s most intriguing observations: metabolic rate scales with body mass to the 3/4 power across species from flies to elephants.

Solar power intercepted by an organism also scales to the 3/4 power of mass—nearly identical.

This doesn’t prove causation, but it suggests sunlight could be a universal regulator of metabolic activity across the biosphere, with mitochondria in all organisms tuned to respond to the same infrared wavelengths present in Earth’s solar photon field.

What Makes This Hypothesis Different

Earlier theories proposed infrared light works by activating a photoreceptor in cytochrome c oxidase (complex IV) or by reducing water viscosity around ATP synthase motors.

Seheult’s team doesn’t reject these mechanisms—but argues they’re incomplete.

The Marcus framework explains phenomena earlier models couldn’t: why some infrared wavelengths inhibit rather than enhance mitochondrial activity, why broadband light outperforms monochromatic sources, and why effects persist across vastly different organisms.

The paper is the first to integrate four separate literature streams:

• Mitochondrial electron transfer follows Marcus physics
• Red and near-infrared light alter mitochondrial function
• Water and protein structures affect electron transfer kinetics
• Infrared radiation changes molecular electron transfer rates

“The novelty lies in the mechanistic integration,” Seheult emphasizes, “not in any single component.”

What Comes Next

The hypothesis is testable. Future experiments could measure how different infrared wavelengths alter specific Marcus crossing configurations in isolated mitochondrial complexes, or track real-time changes in reorganization energy using advanced spectroscopy.

If validated, the implications extend far beyond biology. Urban planning, architecture, workplace design, and lighting standards may all need reconsideration.

Seheult introduces a new term: photometabolism—solar-driven, non-photosynthetic modulation of core metabolic processes.

It’s a concept that positions sunlight not as a passive environmental factor, but as an active participant in the biochemistry of life itself.

I believe that this hypothesis if true has major implications for the built environment and how we live and the type of light that we require to live, and I believe it’s one of the major reasons why we need to be treating our patients outside.

Sources

• Jeffery et al. (2025) – Longer wavelengths in sunlight penetrating human tissue
• Ma et al. (2018) – Infrared perturbation of charge separation and recombination
• Sanderson et al. (2018) – Inhibitory modulation of cytochrome c oxidase with near-infrared wavelengths
• Dai et al. (2026) – Infrared stimulation of mitochondrial metabolism in deep-sea yeast
• Hayashi et al. (2010) – Water-mediated electron transfer in iron-sulfur bridges
• Marcus and Sutin (1985) – Electron transfer reactions in chemistry

The work brings together experts from astrophysics, neuroscience, lighting engineering, and medicine to explain why sunlight may be far more than just a source of vitamin D.

If the hypothesis holds, it suggests our modern indoor environments—filled with LED lighting and low-E glass windows that block infrared—may be quietly undermining our metabolic health.

The Core Hypothesis: Sunlight Tunes Mitochondrial Machinery

Seheult and his collaborators propose that infrared light from the sun acts as a metabolic modulator by influencing how efficiently electrons move through the mitochondrial electron transport chain.

“Electrons move best when the surrounding molecules are arranged just right,” Seheult explains. “Infrared light causes those molecules to vibrate, changing how often the mitochondria reach those favorable arrangements.”

Unlike previous theories that focused on a single photoreceptor in one mitochondrial protein, this new framework suggests infrared light works across multiple pathways simultaneously by altering the vibrational energy of proteins, water, and lipids that surround electron transfer sites.

Why Sunlight Penetrates Deeper Than You Think

Most people assume sunlight only affects the skin surface. But research published in 2025 by Dr. Glenn Jeffery’s group demonstrated that longer wavelengths of infrared light can pass completely through human tissue.

Light is able to go through the body. It is able to be absorbed and it is doing stuff in the body.

In one striking experiment, 850-nanometer light was shown passing through a human hand with measurable intensity on the other side. Infrared wavelengths between 750 and 1,000 nanometers can even penetrate clothing.

This discovery opens the door to a startling possibility: infrared photons from the sun may be reaching mitochondria deep inside the body and influencing their activity in real time.

The Sun’s Special Infrared Signature

Not all light sources are created equal. The sun emits a broad spectrum of infrared wavelengths, but one particular photon energy—0.754 electron volts—is especially abundant.

This peak occurs because of the sun’s photosphere, a layer rich in negatively charged hydrogen atoms called hydride ions. These ions absorb higher-energy photons and re-emit them at exactly 0.754 electron volts.

Seheult likens it to dollar bills falling from the sky. While visible light carries the most total energy (like $100 bills), infrared photons are the most numerous (like $1 bills).

The result? A unique atmospheric window that allows these photons to reach Earth’s surface in abundance—and potentially interact with living cells in ways artificial light cannot replicate.

Marcus Electron Transfer: The Physics Behind the Biology

To understand how infrared light affects mitochondria, Seheult’s team turned to Marcus electron transfer theory, pioneered by Nobel laureate Rudolph Marcus in the 1960s.

Electrons don’t jump spontaneously between molecules. They require surrounding proteins, water, and lipids to twist into precise configurations—a process that demands energy called “reorganization energy.”

When infrared light hits these structures, it causes them to vibrate. This shifts the probability that molecules will be in the right arrangement for electron transfer to occur.

• If the crossing point is already accessible: Infrared light can push molecules away from optimal configurations, slowing electron transfer
• If the crossing point requires activation: Infrared light can push molecules toward optimal configurations, speeding electron transfer

This explains a puzzling finding from earlier studies: different infrared wavelengths can either increase or decrease mitochondrial activity.

Experiments Confirm the Mechanism

A 2018 study by Ma and colleagues tested this exact principle. Researchers built a custom molecule and used mid-infrared light to excite vibrational modes.

They found infrared light slowed forward electron transfer but accelerated backward transfer—precisely what Marcus theory predicts when nuclear orientations are shifted along energy curves.

IR excitation increases the probability of donor and acceptor energies to remain in degeneracy, resulting in IR-induced electron transfer rate enhancement.

Seheult notes he and co-author Dr. Robert Fosbury spoke with Marcus himself—just months before the scientist passed away at age 102—to discuss their hypothesis.

Deep-Sea Yeast Thrives on Infrared Light—Without Photosynthesis

Perhaps the most striking evidence comes from an unexpected source: yeast living near hydrothermal vents at the bottom of the ocean.

A 2026 study by Dai and colleagues isolated yeast from sediments near a “black smoker” chimney in the central Indian Ocean, more than half a meter from superheated mineral plumes reaching 378°C.

When researchers exposed these yeast cultures to near-infrared light (810–1050 nm) in temperature-controlled conditions, growth increased dramatically compared to dark controls—even though the yeast cannot photosynthesize.

Infrared light outperformed glucose. Adding glucose increased biomass by only 1.3-fold (not statistically significant), while 880-nanometer infrared light produced a threefold increase.

When researchers blocked cytochrome c oxidase (complex IV in mitochondria), near-infrared-stimulated growth dropped by 44%—suggesting the effect operates directly on mitochondrial machinery.

Cold Temperatures, Warm Light

Even more remarkable: infrared light allowed yeast to grow at cooler temperatures where dark controls remained dormant.

At 20°C, yeast exposed to 880-nanometer light grew vigorously while dark controls showed minimal activity. The effective activation energy dropped from 12 kilocalories per mole to just 2 kilocalories per mole.

Infrared light was making up for the cold temperatures by supplying vibrational activation rather than thermal activation.

Proteomics revealed the most upregulated protein after infrared exposure was a mitochondrial ribosomal protein (MRPs8), increased 6.7-fold.

Why Broadband Sunlight May Beat Monochromatic LEDs

Clinical studies using single-wavelength infrared devices have shown benefits—from reducing ICU length of stay to improving muscle strength in COVID-19 patients.

But Seheult’s hypothesis suggests broadband infrared from the sun may be even more effective.

“Sunlight contains a broad spectrum of wavelengths that can interact with many different vibrational modes and electron transfer steps,” he explains, “rather than targeting only one narrow pathway.”

Research from Jeffery’s lab supports this. When comparing monochromatic 850-nanometer light to a 60-watt incandescent bulb (which emits broad-spectrum infrared), the incandescent bulb produced greater improvements in color blindness.

• Monochromatic 850 nm: 9% improvement (head and body), 5% (body only)
• 60W incandescent bulb: 28% improvement, sustained for weeks

The research here aligns with the hypothesis, though direct mechanistic proof in human mitochondria remains to be demonstrated.

The Modern Indoor Environment: A Metabolic Desert?

LED bulbs emit virtually no infrared radiation. Low-emissivity (Low-E) glass windows, designed to improve energy efficiency, block infrared wavelengths.

Seheult measured infrared exposure in his own dining room with windows open: 0.8 watts per square meter.

Step outside under a shade tree with grass reflecting sunlight? 41.9 watts per square meter—more than 50 times higher.

We have set up a situation where outdoors we’re getting plenty of infrared light, versus being indoors where we have Low-E glass blocking it and LED bulbs producing none.

This raises profound questions about whether chronic infrared deficiency could contribute to the rising burden of metabolic diseases, especially among populations spending most of their time indoors.

Seasonal Mortality Patterns Point to Sunlight’s Role

Death rates from heart disease, cancer, stroke, Alzheimer’s, diabetes, and respiratory illness all peak one to three weeks after the shortest day of the year and bottom out after the longest day.

This pattern holds across both infectious and non-infectious causes. The seasonal variation in heart disease deaths alone exceeds total influenza deaths during flu season.

Australia shows the same pattern, but shifted six months—deaths peak in July, their winter. Singapore, 80 miles from the equator with year-round sun, shows no seasonal mortality pattern.

Multiple studies have linked mortality rates to latitude, independent of vitamin D levels, suggesting sunlight itself—particularly its infrared component—plays a direct metabolic role.

Hospitals Are Bringing Patients Outside

Armed with mounting evidence, hospitals worldwide are redesigning care spaces to maximize sunlight exposure.

A $1.5 billion hospital in Footscray, Australia, built ICU beds with direct outdoor access. King’s College Hospital in London invested £2 million to transform its rooftop into a critical care garden where up to six ICU patients can receive treatment surrounded by greenery and natural light.

St. George’s Hospital in London followed suit, creating a neurointensive care rooftop unit. Queen Camilla visited the facility in 2026 to recognize the innovation.

Randomized controlled trials using infrared vests delivering roughly 20–30 watts per square meter (comparable to sitting under a tree) showed 30% reductions in ICU length of stay and improved muscle strength in critically ill COVID-19 patients.

Metabolic Scaling Matches Solar Power Scaling

One of the paper’s most intriguing observations: metabolic rate scales with body mass to the 3/4 power across species from flies to elephants.

Solar power intercepted by an organism also scales to the 3/4 power of mass—nearly identical.

This doesn’t prove causation, but it suggests sunlight could be a universal regulator of metabolic activity across the biosphere, with mitochondria in all organisms tuned to respond to the same infrared wavelengths present in Earth’s solar photon field.

What Makes This Hypothesis Different

Earlier theories proposed infrared light works by activating a photoreceptor in cytochrome c oxidase (complex IV) or by reducing water viscosity around ATP synthase motors.

Seheult’s team doesn’t reject these mechanisms—but argues they’re incomplete.

The Marcus framework explains phenomena earlier models couldn’t: why some infrared wavelengths inhibit rather than enhance mitochondrial activity, why broadband light outperforms monochromatic sources, and why effects persist across vastly different organisms.

The paper is the first to integrate four separate literature streams:

• Mitochondrial electron transfer follows Marcus physics
• Red and near-infrared light alter mitochondrial function
• Water and protein structures affect electron transfer kinetics
• Infrared radiation changes molecular electron transfer rates

“The novelty lies in the mechanistic integration,” Seheult emphasizes, “not in any single component.”

What Comes Next

The hypothesis is testable. Future experiments could measure how different infrared wavelengths alter specific Marcus crossing configurations in isolated mitochondrial complexes, or track real-time changes in reorganization energy using advanced spectroscopy.

If validated, the implications extend far beyond biology. Urban planning, architecture, workplace design, and lighting standards may all need reconsideration.

Seheult introduces a new term: photometabolism—solar-driven, non-photosynthetic modulation of core metabolic processes.

It’s a concept that positions sunlight not as a passive environmental factor, but as an active participant in the biochemistry of life itself.

I believe that this hypothesis if true has major implications for the built environment and how we live and the type of light that we require to live, and I believe it’s one of the major reasons why we need to be treating our patients outside.

Sources

• Jeffery et al. (2025) – Longer wavelengths in sunlight penetrating human tissue
• Ma et al. (2018) – Infrared perturbation of charge separation and recombination
• Sanderson et al. (2018) – Inhibitory modulation of cytochrome c oxidase with near-infrared wavelengths
• Dai et al. (2026) – Infrared stimulation of mitochondrial metabolism in deep-sea yeast
• Hayashi et al. (2010) – Water-mediated electron transfer in iron-sulfur bridges
• Marcus and Sutin (1985) – Electron transfer reactions in chemistry

Dr. Roger Seheult, co-founder of MedCram, has spent a year developing a preprint paper titled “Metabolism in the Solar Photon Field” that proposes a radical explanation for how infrared light from the sun directly affects the mitochondria—the powerhouses of our cells.

The work brings together experts from astrophysics, neuroscience, lighting engineering, and medicine to explain why sunlight may be far more than just a source of vitamin D.

If the hypothesis holds, it suggests our modern indoor environments—filled with LED lighting and low-E glass windows that block infrared—may be quietly undermining our metabolic health.

The Core Hypothesis: Sunlight Tunes Mitochondrial Machinery

Seheult and his collaborators propose that infrared light from the sun acts as a metabolic modulator by influencing how efficiently electrons move through the mitochondrial electron transport chain.

“Electrons move best when the surrounding molecules are arranged just right,” Seheult explains. “Infrared light causes those molecules to vibrate, changing how often the mitochondria reach those favorable arrangements.”

Unlike previous theories that focused on a single photoreceptor in one mitochondrial protein, this new framework suggests infrared light works across multiple pathways simultaneously by altering the vibrational energy of proteins, water, and lipids that surround electron transfer sites.

Why Sunlight Penetrates Deeper Than You Think

Most people assume sunlight only affects the skin surface. But research published in 2025 by Dr. Glenn Jeffery’s group demonstrated that longer wavelengths of infrared light can pass completely through human tissue.

Light is able to go through the body. It is able to be absorbed and it is doing stuff in the body.

In one striking experiment, 850-nanometer light was shown passing through a human hand with measurable intensity on the other side. Infrared wavelengths between 750 and 1,000 nanometers can even penetrate clothing.

This discovery opens the door to a startling possibility: infrared photons from the sun may be reaching mitochondria deep inside the body and influencing their activity in real time.

The Sun’s Special Infrared Signature

Not all light sources are created equal. The sun emits a broad spectrum of infrared wavelengths, but one particular photon energy—0.754 electron volts—is especially abundant.

This peak occurs because of the sun’s photosphere, a layer rich in negatively charged hydrogen atoms called hydride ions. These ions absorb higher-energy photons and re-emit them at exactly 0.754 electron volts.

Seheult likens it to dollar bills falling from the sky. While visible light carries the most total energy (like $100 bills), infrared photons are the most numerous (like $1 bills).

The result? A unique atmospheric window that allows these photons to reach Earth’s surface in abundance—and potentially interact with living cells in ways artificial light cannot replicate.

Marcus Electron Transfer: The Physics Behind the Biology

To understand how infrared light affects mitochondria, Seheult’s team turned to Marcus electron transfer theory, pioneered by Nobel laureate Rudolph Marcus in the 1960s.

Electrons don’t jump spontaneously between molecules. They require surrounding proteins, water, and lipids to twist into precise configurations—a process that demands energy called “reorganization energy.”

When infrared light hits these structures, it causes them to vibrate. This shifts the probability that molecules will be in the right arrangement for electron transfer to occur.

• If the crossing point is already accessible: Infrared light can push molecules away from optimal configurations, slowing electron transfer
• If the crossing point requires activation: Infrared light can push molecules toward optimal configurations, speeding electron transfer

This explains a puzzling finding from earlier studies: different infrared wavelengths can either increase or decrease mitochondrial activity.

Experiments Confirm the Mechanism

A 2018 study by Ma and colleagues tested this exact principle. Researchers built a custom molecule and used mid-infrared light to excite vibrational modes.

They found infrared light slowed forward electron transfer but accelerated backward transfer—precisely what Marcus theory predicts when nuclear orientations are shifted along energy curves.

IR excitation increases the probability of donor and acceptor energies to remain in degeneracy, resulting in IR-induced electron transfer rate enhancement.

Seheult notes he and co-author Dr. Robert Fosbury spoke with Marcus himself—just months before the scientist passed away at age 102—to discuss their hypothesis.

Deep-Sea Yeast Thrives on Infrared Light—Without Photosynthesis

Perhaps the most striking evidence comes from an unexpected source: yeast living near hydrothermal vents at the bottom of the ocean.

A 2026 study by Dai and colleagues isolated yeast from sediments near a “black smoker” chimney in the central Indian Ocean, more than half a meter from superheated mineral plumes reaching 378°C.

When researchers exposed these yeast cultures to near-infrared light (810–1050 nm) in temperature-controlled conditions, growth increased dramatically compared to dark controls—even though the yeast cannot photosynthesize.

Infrared light outperformed glucose. Adding glucose increased biomass by only 1.3-fold (not statistically significant), while 880-nanometer infrared light produced a threefold increase.

When researchers blocked cytochrome c oxidase (complex IV in mitochondria), near-infrared-stimulated growth dropped by 44%—suggesting the effect operates directly on mitochondrial machinery.

Cold Temperatures, Warm Light

Even more remarkable: infrared light allowed yeast to grow at cooler temperatures where dark controls remained dormant.

At 20°C, yeast exposed to 880-nanometer light grew vigorously while dark controls showed minimal activity. The effective activation energy dropped from 12 kilocalories per mole to just 2 kilocalories per mole.

Infrared light was making up for the cold temperatures by supplying vibrational activation rather than thermal activation.

Proteomics revealed the most upregulated protein after infrared exposure was a mitochondrial ribosomal protein (MRPs8), increased 6.7-fold.

Why Broadband Sunlight May Beat Monochromatic LEDs

Clinical studies using single-wavelength infrared devices have shown benefits—from reducing ICU length of stay to improving muscle strength in COVID-19 patients.

But Seheult’s hypothesis suggests broadband infrared from the sun may be even more effective.

“Sunlight contains a broad spectrum of wavelengths that can interact with many different vibrational modes and electron transfer steps,” he explains, “rather than targeting only one narrow pathway.”

Research from Jeffery’s lab supports this. When comparing monochromatic 850-nanometer light to a 60-watt incandescent bulb (which emits broad-spectrum infrared), the incandescent bulb produced greater improvements in color blindness.

• Monochromatic 850 nm: 9% improvement (head and body), 5% (body only)
• 60W incandescent bulb: 28% improvement, sustained for weeks

The research here aligns with the hypothesis, though direct mechanistic proof in human mitochondria remains to be demonstrated.

The Modern Indoor Environment: A Metabolic Desert?

LED bulbs emit virtually no infrared radiation. Low-emissivity (Low-E) glass windows, designed to improve energy efficiency, block infrared wavelengths.

Seheult measured infrared exposure in his own dining room with windows open: 0.8 watts per square meter.

Step outside under a shade tree with grass reflecting sunlight? 41.9 watts per square meter—more than 50 times higher.

We have set up a situation where outdoors we’re getting plenty of infrared light, versus being indoors where we have Low-E glass blocking it and LED bulbs producing none.

This raises profound questions about whether chronic infrared deficiency could contribute to the rising burden of metabolic diseases, especially among populations spending most of their time indoors.

Seasonal Mortality Patterns Point to Sunlight’s Role

Death rates from heart disease, cancer, stroke, Alzheimer’s, diabetes, and respiratory illness all peak one to three weeks after the shortest day of the year and bottom out after the longest day.

This pattern holds across both infectious and non-infectious causes. The seasonal variation in heart disease deaths alone exceeds total influenza deaths during flu season.

Australia shows the same pattern, but shifted six months—deaths peak in July, their winter. Singapore, 80 miles from the equator with year-round sun, shows no seasonal mortality pattern.

Multiple studies have linked mortality rates to latitude, independent of vitamin D levels, suggesting sunlight itself—particularly its infrared component—plays a direct metabolic role.

Hospitals Are Bringing Patients Outside

Armed with mounting evidence, hospitals worldwide are redesigning care spaces to maximize sunlight exposure.

A $1.5 billion hospital in Footscray, Australia, built ICU beds with direct outdoor access. King’s College Hospital in London invested £2 million to transform its rooftop into a critical care garden where up to six ICU patients can receive treatment surrounded by greenery and natural light.

St. George’s Hospital in London followed suit, creating a neurointensive care rooftop unit. Queen Camilla visited the facility in 2026 to recognize the innovation.

Randomized controlled trials using infrared vests delivering roughly 20–30 watts per square meter (comparable to sitting under a tree) showed 30% reductions in ICU length of stay and improved muscle strength in critically ill COVID-19 patients.

Metabolic Scaling Matches Solar Power Scaling

One of the paper’s most intriguing observations: metabolic rate scales with body mass to the 3/4 power across species from flies to elephants.

Solar power intercepted by an organism also scales to the 3/4 power of mass—nearly identical.

This doesn’t prove causation, but it suggests sunlight could be a universal regulator of metabolic activity across the biosphere, with mitochondria in all organisms tuned to respond to the same infrared wavelengths present in Earth’s solar photon field.

What Makes This Hypothesis Different

Earlier theories proposed infrared light works by activating a photoreceptor in cytochrome c oxidase (complex IV) or by reducing water viscosity around ATP synthase motors.

Seheult’s team doesn’t reject these mechanisms—but argues they’re incomplete.

The Marcus framework explains phenomena earlier models couldn’t: why some infrared wavelengths inhibit rather than enhance mitochondrial activity, why broadband light outperforms monochromatic sources, and why effects persist across vastly different organisms.

The paper is the first to integrate four separate literature streams:

• Mitochondrial electron transfer follows Marcus physics
• Red and near-infrared light alter mitochondrial function
• Water and protein structures affect electron transfer kinetics
• Infrared radiation changes molecular electron transfer rates

“The novelty lies in the mechanistic integration,” Seheult emphasizes, “not in any single component.”

What Comes Next

The hypothesis is testable. Future experiments could measure how different infrared wavelengths alter specific Marcus crossing configurations in isolated mitochondrial complexes, or track real-time changes in reorganization energy using advanced spectroscopy.

If validated, the implications extend far beyond biology. Urban planning, architecture, workplace design, and lighting standards may all need reconsideration.

Seheult introduces a new term: photometabolism—solar-driven, non-photosynthetic modulation of core metabolic processes.

It’s a concept that positions sunlight not as a passive environmental factor, but as an active participant in the biochemistry of life itself.

I believe that this hypothesis if true has major implications for the built environment and how we live and the type of light that we require to live, and I believe it’s one of the major reasons why we need to be treating our patients outside.

Sources

• Jeffery et al. (2025) – Longer wavelengths in sunlight penetrating human tissue
• Ma et al. (2018) – Infrared perturbation of charge separation and recombination
• Sanderson et al. (2018) – Inhibitory modulation of cytochrome c oxidase with near-infrared wavelengths
• Dai et al. (2026) – Infrared stimulation of mitochondrial metabolism in deep-sea yeast
• Hayashi et al. (2010) – Water-mediated electron transfer in iron-sulfur bridges
• Marcus and Sutin (1985) – Electron transfer reactions in chemistry

Dr. Roger Seheult, co-founder of MedCram, has spent a year developing a preprint paper titled “Metabolism in the Solar Photon Field” that proposes a radical explanation for how infrared light from the sun directly affects the mitochondria—the powerhouses of our cells.

The work brings together experts from astrophysics, neuroscience, lighting engineering, and medicine to explain why sunlight may be far more than just a source of vitamin D.

If the hypothesis holds, it suggests our modern indoor environments—filled with LED lighting and low-E glass windows that block infrared—may be quietly undermining our metabolic health.

The Core Hypothesis: Sunlight Tunes Mitochondrial Machinery

Seheult and his collaborators propose that infrared light from the sun acts as a metabolic modulator by influencing how efficiently electrons move through the mitochondrial electron transport chain.

“Electrons move best when the surrounding molecules are arranged just right,” Seheult explains. “Infrared light causes those molecules to vibrate, changing how often the mitochondria reach those favorable arrangements.”

Unlike previous theories that focused on a single photoreceptor in one mitochondrial protein, this new framework suggests infrared light works across multiple pathways simultaneously by altering the vibrational energy of proteins, water, and lipids that surround electron transfer sites.

Why Sunlight Penetrates Deeper Than You Think

Most people assume sunlight only affects the skin surface. But research published in 2025 by Dr. Glenn Jeffery’s group demonstrated that longer wavelengths of infrared light can pass completely through human tissue.

Light is able to go through the body. It is able to be absorbed and it is doing stuff in the body.

In one striking experiment, 850-nanometer light was shown passing through a human hand with measurable intensity on the other side. Infrared wavelengths between 750 and 1,000 nanometers can even penetrate clothing.

This discovery opens the door to a startling possibility: infrared photons from the sun may be reaching mitochondria deep inside the body and influencing their activity in real time.

The Sun’s Special Infrared Signature

Not all light sources are created equal. The sun emits a broad spectrum of infrared wavelengths, but one particular photon energy—0.754 electron volts—is especially abundant.

This peak occurs because of the sun’s photosphere, a layer rich in negatively charged hydrogen atoms called hydride ions. These ions absorb higher-energy photons and re-emit them at exactly 0.754 electron volts.

Seheult likens it to dollar bills falling from the sky. While visible light carries the most total energy (like $100 bills), infrared photons are the most numerous (like $1 bills).

The result? A unique atmospheric window that allows these photons to reach Earth’s surface in abundance—and potentially interact with living cells in ways artificial light cannot replicate.

Marcus Electron Transfer: The Physics Behind the Biology

To understand how infrared light affects mitochondria, Seheult’s team turned to Marcus electron transfer theory, pioneered by Nobel laureate Rudolph Marcus in the 1960s.

Electrons don’t jump spontaneously between molecules. They require surrounding proteins, water, and lipids to twist into precise configurations—a process that demands energy called “reorganization energy.”

When infrared light hits these structures, it causes them to vibrate. This shifts the probability that molecules will be in the right arrangement for electron transfer to occur.

• If the crossing point is already accessible: Infrared light can push molecules away from optimal configurations, slowing electron transfer
• If the crossing point requires activation: Infrared light can push molecules toward optimal configurations, speeding electron transfer

This explains a puzzling finding from earlier studies: different infrared wavelengths can either increase or decrease mitochondrial activity.

Experiments Confirm the Mechanism

A 2018 study by Ma and colleagues tested this exact principle. Researchers built a custom molecule and used mid-infrared light to excite vibrational modes.

They found infrared light slowed forward electron transfer but accelerated backward transfer—precisely what Marcus theory predicts when nuclear orientations are shifted along energy curves.

IR excitation increases the probability of donor and acceptor energies to remain in degeneracy, resulting in IR-induced electron transfer rate enhancement.

Seheult notes he and co-author Dr. Robert Fosbury spoke with Marcus himself—just months before the scientist passed away at age 102—to discuss their hypothesis.

Deep-Sea Yeast Thrives on Infrared Light—Without Photosynthesis

Perhaps the most striking evidence comes from an unexpected source: yeast living near hydrothermal vents at the bottom of the ocean.

A 2026 study by Dai and colleagues isolated yeast from sediments near a “black smoker” chimney in the central Indian Ocean, more than half a meter from superheated mineral plumes reaching 378°C.

When researchers exposed these yeast cultures to near-infrared light (810–1050 nm) in temperature-controlled conditions, growth increased dramatically compared to dark controls—even though the yeast cannot photosynthesize.

Infrared light outperformed glucose. Adding glucose increased biomass by only 1.3-fold (not statistically significant), while 880-nanometer infrared light produced a threefold increase.

When researchers blocked cytochrome c oxidase (complex IV in mitochondria), near-infrared-stimulated growth dropped by 44%—suggesting the effect operates directly on mitochondrial machinery.

Cold Temperatures, Warm Light

Even more remarkable: infrared light allowed yeast to grow at cooler temperatures where dark controls remained dormant.

At 20°C, yeast exposed to 880-nanometer light grew vigorously while dark controls showed minimal activity. The effective activation energy dropped from 12 kilocalories per mole to just 2 kilocalories per mole.

Infrared light was making up for the cold temperatures by supplying vibrational activation rather than thermal activation.

Proteomics revealed the most upregulated protein after infrared exposure was a mitochondrial ribosomal protein (MRPs8), increased 6.7-fold.

Why Broadband Sunlight May Beat Monochromatic LEDs

Clinical studies using single-wavelength infrared devices have shown benefits—from reducing ICU length of stay to improving muscle strength in COVID-19 patients.

But Seheult’s hypothesis suggests broadband infrared from the sun may be even more effective.

“Sunlight contains a broad spectrum of wavelengths that can interact with many different vibrational modes and electron transfer steps,” he explains, “rather than targeting only one narrow pathway.”

Research from Jeffery’s lab supports this. When comparing monochromatic 850-nanometer light to a 60-watt incandescent bulb (which emits broad-spectrum infrared), the incandescent bulb produced greater improvements in color blindness.

• Monochromatic 850 nm: 9% improvement (head and body), 5% (body only)
• 60W incandescent bulb: 28% improvement, sustained for weeks

The research here aligns with the hypothesis, though direct mechanistic proof in human mitochondria remains to be demonstrated.

The Modern Indoor Environment: A Metabolic Desert?

LED bulbs emit virtually no infrared radiation. Low-emissivity (Low-E) glass windows, designed to improve energy efficiency, block infrared wavelengths.

Seheult measured infrared exposure in his own dining room with windows open: 0.8 watts per square meter.

Step outside under a shade tree with grass reflecting sunlight? 41.9 watts per square meter—more than 50 times higher.

We have set up a situation where outdoors we’re getting plenty of infrared light, versus being indoors where we have Low-E glass blocking it and LED bulbs producing none.

This raises profound questions about whether chronic infrared deficiency could contribute to the rising burden of metabolic diseases, especially among populations spending most of their time indoors.

Seasonal Mortality Patterns Point to Sunlight’s Role

Death rates from heart disease, cancer, stroke, Alzheimer’s, diabetes, and respiratory illness all peak one to three weeks after the shortest day of the year and bottom out after the longest day.

This pattern holds across both infectious and non-infectious causes. The seasonal variation in heart disease deaths alone exceeds total influenza deaths during flu season.

Australia shows the same pattern, but shifted six months—deaths peak in July, their winter. Singapore, 80 miles from the equator with year-round sun, shows no seasonal mortality pattern.

Multiple studies have linked mortality rates to latitude, independent of vitamin D levels, suggesting sunlight itself—particularly its infrared component—plays a direct metabolic role.

Hospitals Are Bringing Patients Outside

Armed with mounting evidence, hospitals worldwide are redesigning care spaces to maximize sunlight exposure.

A $1.5 billion hospital in Footscray, Australia, built ICU beds with direct outdoor access. King’s College Hospital in London invested £2 million to transform its rooftop into a critical care garden where up to six ICU patients can receive treatment surrounded by greenery and natural light.

St. George’s Hospital in London followed suit, creating a neurointensive care rooftop unit. Queen Camilla visited the facility in 2026 to recognize the innovation.

Randomized controlled trials using infrared vests delivering roughly 20–30 watts per square meter (comparable to sitting under a tree) showed 30% reductions in ICU length of stay and improved muscle strength in critically ill COVID-19 patients.

Metabolic Scaling Matches Solar Power Scaling

One of the paper’s most intriguing observations: metabolic rate scales with body mass to the 3/4 power across species from flies to elephants.

Solar power intercepted by an organism also scales to the 3/4 power of mass—nearly identical.

This doesn’t prove causation, but it suggests sunlight could be a universal regulator of metabolic activity across the biosphere, with mitochondria in all organisms tuned to respond to the same infrared wavelengths present in Earth’s solar photon field.

What Makes This Hypothesis Different

Earlier theories proposed infrared light works by activating a photoreceptor in cytochrome c oxidase (complex IV) or by reducing water viscosity around ATP synthase motors.

Seheult’s team doesn’t reject these mechanisms—but argues they’re incomplete.

The Marcus framework explains phenomena earlier models couldn’t: why some infrared wavelengths inhibit rather than enhance mitochondrial activity, why broadband light outperforms monochromatic sources, and why effects persist across vastly different organisms.

The paper is the first to integrate four separate literature streams:

• Mitochondrial electron transfer follows Marcus physics
• Red and near-infrared light alter mitochondrial function
• Water and protein structures affect electron transfer kinetics
• Infrared radiation changes molecular electron transfer rates

“The novelty lies in the mechanistic integration,” Seheult emphasizes, “not in any single component.”

What Comes Next

The hypothesis is testable. Future experiments could measure how different infrared wavelengths alter specific Marcus crossing configurations in isolated mitochondrial complexes, or track real-time changes in reorganization energy using advanced spectroscopy.

If validated, the implications extend far beyond biology. Urban planning, architecture, workplace design, and lighting standards may all need reconsideration.

Seheult introduces a new term: photometabolism—solar-driven, non-photosynthetic modulation of core metabolic processes.

It’s a concept that positions sunlight not as a passive environmental factor, but as an active participant in the biochemistry of life itself.

I believe that this hypothesis if true has major implications for the built environment and how we live and the type of light that we require to live, and I believe it’s one of the major reasons why we need to be treating our patients outside.

Sources

• Jeffery et al. (2025) – Longer wavelengths in sunlight penetrating human tissue
• Ma et al. (2018) – Infrared perturbation of charge separation and recombination
• Sanderson et al. (2018) – Inhibitory modulation of cytochrome c oxidase with near-infrared wavelengths
• Dai et al. (2026) – Infrared stimulation of mitochondrial metabolism in deep-sea yeast
• Hayashi et al. (2010) – Water-mediated electron transfer in iron-sulfur bridges
• Marcus and Sutin (1985) – Electron transfer reactions in chemistry

A new hypothesis about how sunlight influences human metabolism could reshape our understanding of health, aging, and even hospital design.

Dr. Roger Seheult, co-founder of MedCram, has spent a year developing a preprint paper titled “Metabolism in the Solar Photon Field” that proposes a radical explanation for how infrared light from the sun directly affects the mitochondria—the powerhouses of our cells.

The work brings together experts from astrophysics, neuroscience, lighting engineering, and medicine to explain why sunlight may be far more than just a source of vitamin D.

If the hypothesis holds, it suggests our modern indoor environments—filled with LED lighting and low-E glass windows that block infrared—may be quietly undermining our metabolic health.

The Core Hypothesis: Sunlight Tunes Mitochondrial Machinery

Seheult and his collaborators propose that infrared light from the sun acts as a metabolic modulator by influencing how efficiently electrons move through the mitochondrial electron transport chain.

“Electrons move best when the surrounding molecules are arranged just right,” Seheult explains. “Infrared light causes those molecules to vibrate, changing how often the mitochondria reach those favorable arrangements.”

Unlike previous theories that focused on a single photoreceptor in one mitochondrial protein, this new framework suggests infrared light works across multiple pathways simultaneously by altering the vibrational energy of proteins, water, and lipids that surround electron transfer sites.

Why Sunlight Penetrates Deeper Than You Think

Most people assume sunlight only affects the skin surface. But research published in 2025 by Dr. Glenn Jeffery’s group demonstrated that longer wavelengths of infrared light can pass completely through human tissue.

Light is able to go through the body. It is able to be absorbed and it is doing stuff in the body.

In one striking experiment, 850-nanometer light was shown passing through a human hand with measurable intensity on the other side. Infrared wavelengths between 750 and 1,000 nanometers can even penetrate clothing.

This discovery opens the door to a startling possibility: infrared photons from the sun may be reaching mitochondria deep inside the body and influencing their activity in real time.

The Sun’s Special Infrared Signature

Not all light sources are created equal. The sun emits a broad spectrum of infrared wavelengths, but one particular photon energy—0.754 electron volts—is especially abundant.

This peak occurs because of the sun’s photosphere, a layer rich in negatively charged hydrogen atoms called hydride ions. These ions absorb higher-energy photons and re-emit them at exactly 0.754 electron volts.

Seheult likens it to dollar bills falling from the sky. While visible light carries the most total energy (like $100 bills), infrared photons are the most numerous (like $1 bills).

The result? A unique atmospheric window that allows these photons to reach Earth’s surface in abundance—and potentially interact with living cells in ways artificial light cannot replicate.

Marcus Electron Transfer: The Physics Behind the Biology

To understand how infrared light affects mitochondria, Seheult’s team turned to Marcus electron transfer theory, pioneered by Nobel laureate Rudolph Marcus in the 1960s.

Electrons don’t jump spontaneously between molecules. They require surrounding proteins, water, and lipids to twist into precise configurations—a process that demands energy called “reorganization energy.”

When infrared light hits these structures, it causes them to vibrate. This shifts the probability that molecules will be in the right arrangement for electron transfer to occur.

• If the crossing point is already accessible: Infrared light can push molecules away from optimal configurations, slowing electron transfer
• If the crossing point requires activation: Infrared light can push molecules toward optimal configurations, speeding electron transfer

This explains a puzzling finding from earlier studies: different infrared wavelengths can either increase or decrease mitochondrial activity.

Experiments Confirm the Mechanism

A 2018 study by Ma and colleagues tested this exact principle. Researchers built a custom molecule and used mid-infrared light to excite vibrational modes.

They found infrared light slowed forward electron transfer but accelerated backward transfer—precisely what Marcus theory predicts when nuclear orientations are shifted along energy curves.

IR excitation increases the probability of donor and acceptor energies to remain in degeneracy, resulting in IR-induced electron transfer rate enhancement.

Seheult notes he and co-author Dr. Robert Fosbury spoke with Marcus himself—just months before the scientist passed away at age 102—to discuss their hypothesis.

Deep-Sea Yeast Thrives on Infrared Light—Without Photosynthesis

Perhaps the most striking evidence comes from an unexpected source: yeast living near hydrothermal vents at the bottom of the ocean.

A 2026 study by Dai and colleagues isolated yeast from sediments near a “black smoker” chimney in the central Indian Ocean, more than half a meter from superheated mineral plumes reaching 378°C.

When researchers exposed these yeast cultures to near-infrared light (810–1050 nm) in temperature-controlled conditions, growth increased dramatically compared to dark controls—even though the yeast cannot photosynthesize.

Infrared light outperformed glucose. Adding glucose increased biomass by only 1.3-fold (not statistically significant), while 880-nanometer infrared light produced a threefold increase.

When researchers blocked cytochrome c oxidase (complex IV in mitochondria), near-infrared-stimulated growth dropped by 44%—suggesting the effect operates directly on mitochondrial machinery.

Cold Temperatures, Warm Light

Even more remarkable: infrared light allowed yeast to grow at cooler temperatures where dark controls remained dormant.

At 20°C, yeast exposed to 880-nanometer light grew vigorously while dark controls showed minimal activity. The effective activation energy dropped from 12 kilocalories per mole to just 2 kilocalories per mole.

Infrared light was making up for the cold temperatures by supplying vibrational activation rather than thermal activation.

Proteomics revealed the most upregulated protein after infrared exposure was a mitochondrial ribosomal protein (MRPs8), increased 6.7-fold.

Why Broadband Sunlight May Beat Monochromatic LEDs

Clinical studies using single-wavelength infrared devices have shown benefits—from reducing ICU length of stay to improving muscle strength in COVID-19 patients.

But Seheult’s hypothesis suggests broadband infrared from the sun may be even more effective.

“Sunlight contains a broad spectrum of wavelengths that can interact with many different vibrational modes and electron transfer steps,” he explains, “rather than targeting only one narrow pathway.”

Research from Jeffery’s lab supports this. When comparing monochromatic 850-nanometer light to a 60-watt incandescent bulb (which emits broad-spectrum infrared), the incandescent bulb produced greater improvements in color blindness.

• Monochromatic 850 nm: 9% improvement (head and body), 5% (body only)
• 60W incandescent bulb: 28% improvement, sustained for weeks

The research here aligns with the hypothesis, though direct mechanistic proof in human mitochondria remains to be demonstrated.

The Modern Indoor Environment: A Metabolic Desert?

LED bulbs emit virtually no infrared radiation. Low-emissivity (Low-E) glass windows, designed to improve energy efficiency, block infrared wavelengths.

Seheult measured infrared exposure in his own dining room with windows open: 0.8 watts per square meter.

Step outside under a shade tree with grass reflecting sunlight? 41.9 watts per square meter—more than 50 times higher.

We have set up a situation where outdoors we’re getting plenty of infrared light, versus being indoors where we have Low-E glass blocking it and LED bulbs producing none.

This raises profound questions about whether chronic infrared deficiency could contribute to the rising burden of metabolic diseases, especially among populations spending most of their time indoors.

Seasonal Mortality Patterns Point to Sunlight’s Role

Death rates from heart disease, cancer, stroke, Alzheimer’s, diabetes, and respiratory illness all peak one to three weeks after the shortest day of the year and bottom out after the longest day.

This pattern holds across both infectious and non-infectious causes. The seasonal variation in heart disease deaths alone exceeds total influenza deaths during flu season.

Australia shows the same pattern, but shifted six months—deaths peak in July, their winter. Singapore, 80 miles from the equator with year-round sun, shows no seasonal mortality pattern.

Multiple studies have linked mortality rates to latitude, independent of vitamin D levels, suggesting sunlight itself—particularly its infrared component—plays a direct metabolic role.

Hospitals Are Bringing Patients Outside

Armed with mounting evidence, hospitals worldwide are redesigning care spaces to maximize sunlight exposure.

A $1.5 billion hospital in Footscray, Australia, built ICU beds with direct outdoor access. King’s College Hospital in London invested £2 million to transform its rooftop into a critical care garden where up to six ICU patients can receive treatment surrounded by greenery and natural light.

St. George’s Hospital in London followed suit, creating a neurointensive care rooftop unit. Queen Camilla visited the facility in 2026 to recognize the innovation.

Randomized controlled trials using infrared vests delivering roughly 20–30 watts per square meter (comparable to sitting under a tree) showed 30% reductions in ICU length of stay and improved muscle strength in critically ill COVID-19 patients.

Metabolic Scaling Matches Solar Power Scaling

One of the paper’s most intriguing observations: metabolic rate scales with body mass to the 3/4 power across species from flies to elephants.

Solar power intercepted by an organism also scales to the 3/4 power of mass—nearly identical.

This doesn’t prove causation, but it suggests sunlight could be a universal regulator of metabolic activity across the biosphere, with mitochondria in all organisms tuned to respond to the same infrared wavelengths present in Earth’s solar photon field.

What Makes This Hypothesis Different

Earlier theories proposed infrared light works by activating a photoreceptor in cytochrome c oxidase (complex IV) or by reducing water viscosity around ATP synthase motors.

Seheult’s team doesn’t reject these mechanisms—but argues they’re incomplete.

The Marcus framework explains phenomena earlier models couldn’t: why some infrared wavelengths inhibit rather than enhance mitochondrial activity, why broadband light outperforms monochromatic sources, and why effects persist across vastly different organisms.

The paper is the first to integrate four separate literature streams:

• Mitochondrial electron transfer follows Marcus physics
• Red and near-infrared light alter mitochondrial function
• Water and protein structures affect electron transfer kinetics
• Infrared radiation changes molecular electron transfer rates

“The novelty lies in the mechanistic integration,” Seheult emphasizes, “not in any single component.”

What Comes Next

The hypothesis is testable. Future experiments could measure how different infrared wavelengths alter specific Marcus crossing configurations in isolated mitochondrial complexes, or track real-time changes in reorganization energy using advanced spectroscopy.

If validated, the implications extend far beyond biology. Urban planning, architecture, workplace design, and lighting standards may all need reconsideration.

Seheult introduces a new term: photometabolism—solar-driven, non-photosynthetic modulation of core metabolic processes.

It’s a concept that positions sunlight not as a passive environmental factor, but as an active participant in the biochemistry of life itself.

I believe that this hypothesis if true has major implications for the built environment and how we live and the type of light that we require to live, and I believe it’s one of the major reasons why we need to be treating our patients outside.

Sources

• Jeffery et al. (2025) – Longer wavelengths in sunlight penetrating human tissue
• Ma et al. (2018) – Infrared perturbation of charge separation and recombination
• Sanderson et al. (2018) – Inhibitory modulation of cytochrome c oxidase with near-infrared wavelengths
• Dai et al. (2026) – Infrared stimulation of mitochondrial metabolism in deep-sea yeast
• Hayashi et al. (2010) – Water-mediated electron transfer in iron-sulfur bridges
• Marcus and Sutin (1985) – Electron transfer reactions in chemistry

A new hypothesis about how sunlight influences human metabolism could reshape our understanding of health, aging, and even hospital design.

Dr. Roger Seheult, co-founder of MedCram, has spent a year developing a preprint paper titled “Metabolism in the Solar Photon Field” that proposes a radical explanation for how infrared light from the sun directly affects the mitochondria—the powerhouses of our cells.

The work brings together experts from astrophysics, neuroscience, lighting engineering, and medicine to explain why sunlight may be far more than just a source of vitamin D.

If the hypothesis holds, it suggests our modern indoor environments—filled with LED lighting and low-E glass windows that block infrared—may be quietly undermining our metabolic health.

The Core Hypothesis: Sunlight Tunes Mitochondrial Machinery

Seheult and his collaborators propose that infrared light from the sun acts as a metabolic modulator by influencing how efficiently electrons move through the mitochondrial electron transport chain.

“Electrons move best when the surrounding molecules are arranged just right,” Seheult explains. “Infrared light causes those molecules to vibrate, changing how often the mitochondria reach those favorable arrangements.”

Unlike previous theories that focused on a single photoreceptor in one mitochondrial protein, this new framework suggests infrared light works across multiple pathways simultaneously by altering the vibrational energy of proteins, water, and lipids that surround electron transfer sites.

Why Sunlight Penetrates Deeper Than You Think

Most people assume sunlight only affects the skin surface. But research published in 2025 by Dr. Glenn Jeffery’s group demonstrated that longer wavelengths of infrared light can pass completely through human tissue.

Light is able to go through the body. It is able to be absorbed and it is doing stuff in the body.

In one striking experiment, 850-nanometer light was shown passing through a human hand with measurable intensity on the other side. Infrared wavelengths between 750 and 1,000 nanometers can even penetrate clothing.

This discovery opens the door to a startling possibility: infrared photons from the sun may be reaching mitochondria deep inside the body and influencing their activity in real time.

The Sun’s Special Infrared Signature

Not all light sources are created equal. The sun emits a broad spectrum of infrared wavelengths, but one particular photon energy—0.754 electron volts—is especially abundant.

This peak occurs because of the sun’s photosphere, a layer rich in negatively charged hydrogen atoms called hydride ions. These ions absorb higher-energy photons and re-emit them at exactly 0.754 electron volts.

Seheult likens it to dollar bills falling from the sky. While visible light carries the most total energy (like $100 bills), infrared photons are the most numerous (like $1 bills).

The result? A unique atmospheric window that allows these photons to reach Earth’s surface in abundance—and potentially interact with living cells in ways artificial light cannot replicate.

Marcus Electron Transfer: The Physics Behind the Biology

To understand how infrared light affects mitochondria, Seheult’s team turned to Marcus electron transfer theory, pioneered by Nobel laureate Rudolph Marcus in the 1960s.

Electrons don’t jump spontaneously between molecules. They require surrounding proteins, water, and lipids to twist into precise configurations—a process that demands energy called “reorganization energy.”

When infrared light hits these structures, it causes them to vibrate. This shifts the probability that molecules will be in the right arrangement for electron transfer to occur.

• If the crossing point is already accessible: Infrared light can push molecules away from optimal configurations, slowing electron transfer
• If the crossing point requires activation: Infrared light can push molecules toward optimal configurations, speeding electron transfer

This explains a puzzling finding from earlier studies: different infrared wavelengths can either increase or decrease mitochondrial activity.

Experiments Confirm the Mechanism

A 2018 study by Ma and colleagues tested this exact principle. Researchers built a custom molecule and used mid-infrared light to excite vibrational modes.

They found infrared light slowed forward electron transfer but accelerated backward transfer—precisely what Marcus theory predicts when nuclear orientations are shifted along energy curves.

IR excitation increases the probability of donor and acceptor energies to remain in degeneracy, resulting in IR-induced electron transfer rate enhancement.

Seheult notes he and co-author Dr. Robert Fosbury spoke with Marcus himself—just months before the scientist passed away at age 102—to discuss their hypothesis.

Deep-Sea Yeast Thrives on Infrared Light—Without Photosynthesis

Perhaps the most striking evidence comes from an unexpected source: yeast living near hydrothermal vents at the bottom of the ocean.

A 2026 study by Dai and colleagues isolated yeast from sediments near a “black smoker” chimney in the central Indian Ocean, more than half a meter from superheated mineral plumes reaching 378°C.

When researchers exposed these yeast cultures to near-infrared light (810–1050 nm) in temperature-controlled conditions, growth increased dramatically compared to dark controls—even though the yeast cannot photosynthesize.

Infrared light outperformed glucose. Adding glucose increased biomass by only 1.3-fold (not statistically significant), while 880-nanometer infrared light produced a threefold increase.

When researchers blocked cytochrome c oxidase (complex IV in mitochondria), near-infrared-stimulated growth dropped by 44%—suggesting the effect operates directly on mitochondrial machinery.

Cold Temperatures, Warm Light

Even more remarkable: infrared light allowed yeast to grow at cooler temperatures where dark controls remained dormant.

At 20°C, yeast exposed to 880-nanometer light grew vigorously while dark controls showed minimal activity. The effective activation energy dropped from 12 kilocalories per mole to just 2 kilocalories per mole.

Infrared light was making up for the cold temperatures by supplying vibrational activation rather than thermal activation.

Proteomics revealed the most upregulated protein after infrared exposure was a mitochondrial ribosomal protein (MRPs8), increased 6.7-fold.

Why Broadband Sunlight May Beat Monochromatic LEDs

Clinical studies using single-wavelength infrared devices have shown benefits—from reducing ICU length of stay to improving muscle strength in COVID-19 patients.

But Seheult’s hypothesis suggests broadband infrared from the sun may be even more effective.

“Sunlight contains a broad spectrum of wavelengths that can interact with many different vibrational modes and electron transfer steps,” he explains, “rather than targeting only one narrow pathway.”

Research from Jeffery’s lab supports this. When comparing monochromatic 850-nanometer light to a 60-watt incandescent bulb (which emits broad-spectrum infrared), the incandescent bulb produced greater improvements in color blindness.

• Monochromatic 850 nm: 9% improvement (head and body), 5% (body only)
• 60W incandescent bulb: 28% improvement, sustained for weeks

The research here aligns with the hypothesis, though direct mechanistic proof in human mitochondria remains to be demonstrated.

The Modern Indoor Environment: A Metabolic Desert?

LED bulbs emit virtually no infrared radiation. Low-emissivity (Low-E) glass windows, designed to improve energy efficiency, block infrared wavelengths.

Seheult measured infrared exposure in his own dining room with windows open: 0.8 watts per square meter.

Step outside under a shade tree with grass reflecting sunlight? 41.9 watts per square meter—more than 50 times higher.

We have set up a situation where outdoors we’re getting plenty of infrared light, versus being indoors where we have Low-E glass blocking it and LED bulbs producing none.

This raises profound questions about whether chronic infrared deficiency could contribute to the rising burden of metabolic diseases, especially among populations spending most of their time indoors.

Seasonal Mortality Patterns Point to Sunlight’s Role

Death rates from heart disease, cancer, stroke, Alzheimer’s, diabetes, and respiratory illness all peak one to three weeks after the shortest day of the year and bottom out after the longest day.

This pattern holds across both infectious and non-infectious causes. The seasonal variation in heart disease deaths alone exceeds total influenza deaths during flu season.

Australia shows the same pattern, but shifted six months—deaths peak in July, their winter. Singapore, 80 miles from the equator with year-round sun, shows no seasonal mortality pattern.

Multiple studies have linked mortality rates to latitude, independent of vitamin D levels, suggesting sunlight itself—particularly its infrared component—plays a direct metabolic role.

Hospitals Are Bringing Patients Outside

Armed with mounting evidence, hospitals worldwide are redesigning care spaces to maximize sunlight exposure.

A $1.5 billion hospital in Footscray, Australia, built ICU beds with direct outdoor access. King’s College Hospital in London invested £2 million to transform its rooftop into a critical care garden where up to six ICU patients can receive treatment surrounded by greenery and natural light.

St. George’s Hospital in London followed suit, creating a neurointensive care rooftop unit. Queen Camilla visited the facility in 2026 to recognize the innovation.

Randomized controlled trials using infrared vests delivering roughly 20–30 watts per square meter (comparable to sitting under a tree) showed 30% reductions in ICU length of stay and improved muscle strength in critically ill COVID-19 patients.

Metabolic Scaling Matches Solar Power Scaling

One of the paper’s most intriguing observations: metabolic rate scales with body mass to the 3/4 power across species from flies to elephants.

Solar power intercepted by an organism also scales to the 3/4 power of mass—nearly identical.

This doesn’t prove causation, but it suggests sunlight could be a universal regulator of metabolic activity across the biosphere, with mitochondria in all organisms tuned to respond to the same infrared wavelengths present in Earth’s solar photon field.

What Makes This Hypothesis Different

Earlier theories proposed infrared light works by activating a photoreceptor in cytochrome c oxidase (complex IV) or by reducing water viscosity around ATP synthase motors.

Seheult’s team doesn’t reject these mechanisms—but argues they’re incomplete.

The Marcus framework explains phenomena earlier models couldn’t: why some infrared wavelengths inhibit rather than enhance mitochondrial activity, why broadband light outperforms monochromatic sources, and why effects persist across vastly different organisms.

The paper is the first to integrate four separate literature streams:

• Mitochondrial electron transfer follows Marcus physics
• Red and near-infrared light alter mitochondrial function
• Water and protein structures affect electron transfer kinetics
• Infrared radiation changes molecular electron transfer rates

“The novelty lies in the mechanistic integration,” Seheult emphasizes, “not in any single component.”

What Comes Next

The hypothesis is testable. Future experiments could measure how different infrared wavelengths alter specific Marcus crossing configurations in isolated mitochondrial complexes, or track real-time changes in reorganization energy using advanced spectroscopy.

If validated, the implications extend far beyond biology. Urban planning, architecture, workplace design, and lighting standards may all need reconsideration.

Seheult introduces a new term: photometabolism—solar-driven, non-photosynthetic modulation of core metabolic processes.

It’s a concept that positions sunlight not as a passive environmental factor, but as an active participant in the biochemistry of life itself.

I believe that this hypothesis if true has major implications for the built environment and how we live and the type of light that we require to live, and I believe it’s one of the major reasons why we need to be treating our patients outside.

Sources

• Jeffery et al. (2025) – Longer wavelengths in sunlight penetrating human tissue
• Ma et al. (2018) – Infrared perturbation of charge separation and recombination
• Sanderson et al. (2018) – Inhibitory modulation of cytochrome c oxidase with near-infrared wavelengths
• Dai et al. (2026) – Infrared stimulation of mitochondrial metabolism in deep-sea yeast
• Hayashi et al. (2010) – Water-mediated electron transfer in iron-sulfur bridges
• Marcus and Sutin (1985) – Electron transfer reactions in chemistry

A new hypothesis about how sunlight influences human metabolism could reshape our understanding of health, aging, and even hospital design.

Dr. Roger Seheult, co-founder of MedCram, has spent a year developing a preprint paper titled “Metabolism in the Solar Photon Field” that proposes a radical explanation for how infrared light from the sun directly affects the mitochondria—the powerhouses of our cells.

The work brings together experts from astrophysics, neuroscience, lighting engineering, and medicine to explain why sunlight may be far more than just a source of vitamin D.

If the hypothesis holds, it suggests our modern indoor environments—filled with LED lighting and low-E glass windows that block infrared—may be quietly undermining our metabolic health.

The Core Hypothesis: Sunlight Tunes Mitochondrial Machinery

Seheult and his collaborators propose that infrared light from the sun acts as a metabolic modulator by influencing how efficiently electrons move through the mitochondrial electron transport chain.

“Electrons move best when the surrounding molecules are arranged just right,” Seheult explains. “Infrared light causes those molecules to vibrate, changing how often the mitochondria reach those favorable arrangements.”

Unlike previous theories that focused on a single photoreceptor in one mitochondrial protein, this new framework suggests infrared light works across multiple pathways simultaneously by altering the vibrational energy of proteins, water, and lipids that surround electron transfer sites.

Why Sunlight Penetrates Deeper Than You Think

Most people assume sunlight only affects the skin surface. But research published in 2025 by Dr. Glenn Jeffery’s group demonstrated that longer wavelengths of infrared light can pass completely through human tissue.

Light is able to go through the body. It is able to be absorbed and it is doing stuff in the body.

In one striking experiment, 850-nanometer light was shown passing through a human hand with measurable intensity on the other side. Infrared wavelengths between 750 and 1,000 nanometers can even penetrate clothing.

This discovery opens the door to a startling possibility: infrared photons from the sun may be reaching mitochondria deep inside the body and influencing their activity in real time.

The Sun’s Special Infrared Signature

Not all light sources are created equal. The sun emits a broad spectrum of infrared wavelengths, but one particular photon energy—0.754 electron volts—is especially abundant.

This peak occurs because of the sun’s photosphere, a layer rich in negatively charged hydrogen atoms called hydride ions. These ions absorb higher-energy photons and re-emit them at exactly 0.754 electron volts.

Seheult likens it to dollar bills falling from the sky. While visible light carries the most total energy (like $100 bills), infrared photons are the most numerous (like $1 bills).

The result? A unique atmospheric window that allows these photons to reach Earth’s surface in abundance—and potentially interact with living cells in ways artificial light cannot replicate.

Marcus Electron Transfer: The Physics Behind the Biology

To understand how infrared light affects mitochondria, Seheult’s team turned to Marcus electron transfer theory, pioneered by Nobel laureate Rudolph Marcus in the 1960s.

Electrons don’t jump spontaneously between molecules. They require surrounding proteins, water, and lipids to twist into precise configurations—a process that demands energy called “reorganization energy.”

When infrared light hits these structures, it causes them to vibrate. This shifts the probability that molecules will be in the right arrangement for electron transfer to occur.

• If the crossing point is already accessible: Infrared light can push molecules away from optimal configurations, slowing electron transfer
• If the crossing point requires activation: Infrared light can push molecules toward optimal configurations, speeding electron transfer

This explains a puzzling finding from earlier studies: different infrared wavelengths can either increase or decrease mitochondrial activity.

Experiments Confirm the Mechanism

A 2018 study by Ma and colleagues tested this exact principle. Researchers built a custom molecule and used mid-infrared light to excite vibrational modes.

They found infrared light slowed forward electron transfer but accelerated backward transfer—precisely what Marcus theory predicts when nuclear orientations are shifted along energy curves.

IR excitation increases the probability of donor and acceptor energies to remain in degeneracy, resulting in IR-induced electron transfer rate enhancement.

Seheult notes he and co-author Dr. Robert Fosbury spoke with Marcus himself—just months before the scientist passed away at age 102—to discuss their hypothesis.

Deep-Sea Yeast Thrives on Infrared Light—Without Photosynthesis

Perhaps the most striking evidence comes from an unexpected source: yeast living near hydrothermal vents at the bottom of the ocean.

A 2026 study by Dai and colleagues isolated yeast from sediments near a “black smoker” chimney in the central Indian Ocean, more than half a meter from superheated mineral plumes reaching 378°C.

When researchers exposed these yeast cultures to near-infrared light (810–1050 nm) in temperature-controlled conditions, growth increased dramatically compared to dark controls—even though the yeast cannot photosynthesize.

Infrared light outperformed glucose. Adding glucose increased biomass by only 1.3-fold (not statistically significant), while 880-nanometer infrared light produced a threefold increase.

When researchers blocked cytochrome c oxidase (complex IV in mitochondria), near-infrared-stimulated growth dropped by 44%—suggesting the effect operates directly on mitochondrial machinery.

Cold Temperatures, Warm Light

Even more remarkable: infrared light allowed yeast to grow at cooler temperatures where dark controls remained dormant.

At 20°C, yeast exposed to 880-nanometer light grew vigorously while dark controls showed minimal activity. The effective activation energy dropped from 12 kilocalories per mole to just 2 kilocalories per mole.

Infrared light was making up for the cold temperatures by supplying vibrational activation rather than thermal activation.

Proteomics revealed the most upregulated protein after infrared exposure was a mitochondrial ribosomal protein (MRPs8), increased 6.7-fold.

Why Broadband Sunlight May Beat Monochromatic LEDs

Clinical studies using single-wavelength infrared devices have shown benefits—from reducing ICU length of stay to improving muscle strength in COVID-19 patients.

But Seheult’s hypothesis suggests broadband infrared from the sun may be even more effective.

“Sunlight contains a broad spectrum of wavelengths that can interact with many different vibrational modes and electron transfer steps,” he explains, “rather than targeting only one narrow pathway.”

Research from Jeffery’s lab supports this. When comparing monochromatic 850-nanometer light to a 60-watt incandescent bulb (which emits broad-spectrum infrared), the incandescent bulb produced greater improvements in color blindness.

• Monochromatic 850 nm: 9% improvement (head and body), 5% (body only)
• 60W incandescent bulb: 28% improvement, sustained for weeks

The research here aligns with the hypothesis, though direct mechanistic proof in human mitochondria remains to be demonstrated.

The Modern Indoor Environment: A Metabolic Desert?

LED bulbs emit virtually no infrared radiation. Low-emissivity (Low-E) glass windows, designed to improve energy efficiency, block infrared wavelengths.

Seheult measured infrared exposure in his own dining room with windows open: 0.8 watts per square meter.

Step outside under a shade tree with grass reflecting sunlight? 41.9 watts per square meter—more than 50 times higher.

We have set up a situation where outdoors we’re getting plenty of infrared light, versus being indoors where we have Low-E glass blocking it and LED bulbs producing none.

This raises profound questions about whether chronic infrared deficiency could contribute to the rising burden of metabolic diseases, especially among populations spending most of their time indoors.

Seasonal Mortality Patterns Point to Sunlight’s Role

Death rates from heart disease, cancer, stroke, Alzheimer’s, diabetes, and respiratory illness all peak one to three weeks after the shortest day of the year and bottom out after the longest day.

This pattern holds across both infectious and non-infectious causes. The seasonal variation in heart disease deaths alone exceeds total influenza deaths during flu season.

Australia shows the same pattern, but shifted six months—deaths peak in July, their winter. Singapore, 80 miles from the equator with year-round sun, shows no seasonal mortality pattern.

Multiple studies have linked mortality rates to latitude, independent of vitamin D levels, suggesting sunlight itself—particularly its infrared component—plays a direct metabolic role.

Hospitals Are Bringing Patients Outside

Armed with mounting evidence, hospitals worldwide are redesigning care spaces to maximize sunlight exposure.

A $1.5 billion hospital in Footscray, Australia, built ICU beds with direct outdoor access. King’s College Hospital in London invested £2 million to transform its rooftop into a critical care garden where up to six ICU patients can receive treatment surrounded by greenery and natural light.

St. George’s Hospital in London followed suit, creating a neurointensive care rooftop unit. Queen Camilla visited the facility in 2026 to recognize the innovation.

Randomized controlled trials using infrared vests delivering roughly 20–30 watts per square meter (comparable to sitting under a tree) showed 30% reductions in ICU length of stay and improved muscle strength in critically ill COVID-19 patients.

Metabolic Scaling Matches Solar Power Scaling

One of the paper’s most intriguing observations: metabolic rate scales with body mass to the 3/4 power across species from flies to elephants.

Solar power intercepted by an organism also scales to the 3/4 power of mass—nearly identical.

This doesn’t prove causation, but it suggests sunlight could be a universal regulator of metabolic activity across the biosphere, with mitochondria in all organisms tuned to respond to the same infrared wavelengths present in Earth’s solar photon field.

What Makes This Hypothesis Different

Earlier theories proposed infrared light works by activating a photoreceptor in cytochrome c oxidase (complex IV) or by reducing water viscosity around ATP synthase motors.

Seheult’s team doesn’t reject these mechanisms—but argues they’re incomplete.

The Marcus framework explains phenomena earlier models couldn’t: why some infrared wavelengths inhibit rather than enhance mitochondrial activity, why broadband light outperforms monochromatic sources, and why effects persist across vastly different organisms.

The paper is the first to integrate four separate literature streams:

• Mitochondrial electron transfer follows Marcus physics
• Red and near-infrared light alter mitochondrial function
• Water and protein structures affect electron transfer kinetics
• Infrared radiation changes molecular electron transfer rates

“The novelty lies in the mechanistic integration,” Seheult emphasizes, “not in any single component.”

What Comes Next

The hypothesis is testable. Future experiments could measure how different infrared wavelengths alter specific Marcus crossing configurations in isolated mitochondrial complexes, or track real-time changes in reorganization energy using advanced spectroscopy.

If validated, the implications extend far beyond biology. Urban planning, architecture, workplace design, and lighting standards may all need reconsideration.

Seheult introduces a new term: photometabolism—solar-driven, non-photosynthetic modulation of core metabolic processes.

It’s a concept that positions sunlight not as a passive environmental factor, but as an active participant in the biochemistry of life itself.

I believe that this hypothesis if true has major implications for the built environment and how we live and the type of light that we require to live, and I believe it’s one of the major reasons why we need to be treating our patients outside.

Sources

• Jeffery et al. (2025) – Longer wavelengths in sunlight penetrating human tissue
• Ma et al. (2018) – Infrared perturbation of charge separation and recombination
• Sanderson et al. (2018) – Inhibitory modulation of cytochrome c oxidase with near-infrared wavelengths
• Dai et al. (2026) – Infrared stimulation of mitochondrial metabolism in deep-sea yeast
• Hayashi et al. (2010) – Water-mediated electron transfer in iron-sulfur bridges
• Marcus and Sutin (1985) – Electron transfer reactions in chemistry