Brain Biophotons Detected: The Human Brain Emits Light

Language: en

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Overview

In May 2025, researchers at the University of Calgary published a landmark paper in the Journal of Physical Chemistry Letters reporting the first detection of biophotons emitted by the living human brain from outside the skull. Using ultra-sensitive single-photon detectors cooled to near absolute zero, the team demonstrated that the human brain emits ultra-weak photon emissions (UPE) in the visible and near-infrared spectrum — and that these emissions change measurably with different mental tasks. The brain literally produces light, and the light carries information about mental activity.

This finding vindicates decades of work by the late Fritz-Albert Popp, a German biophysicist who spent his career from the 1970s onward documenting biophoton emissions from living cells and arguing that these ultra-weak light emissions play a functional role in biological communication and regulation. Popp was widely regarded as a fringe scientist during his lifetime. His claim that living organisms emit coherent light and that this light carries biological information was dismissed as pseudoscience by mainstream biology. The Calgary finding does not prove all of Popp’s claims, but it establishes the empirical foundation: the brain emits photons, and these photons correlate with neural activity.

If the body is a biological machine, biophotons are the fiber optic network running alongside the electrical wiring. We have been studying the electrical system (action potentials, EEG, electrophysiology) for over a century. The optical system has been invisible — not because it does not exist, but because the signal is extraordinarily faint and our detectors were not sensitive enough. Until now.

The Discovery

Experimental Setup

The Calgary team, led by researchers in the Department of Physics and the Hotchkiss Brain Institute, used superconducting nanowire single-photon detectors (SNSPDs) — the most sensitive photon detectors ever built, capable of registering individual photons with near-unity detection efficiency and virtually zero dark counts (false detections). The detectors were cooled to approximately 2 Kelvin (-271 degrees C) and coupled to fiber optic collection systems positioned on the scalp.

The experimental challenge was enormous. Biophoton emissions from biological tissue are extraordinarily faint: typically on the order of 10 to 1,000 photons per second per square centimeter of tissue. For comparison, a candle flame emits approximately 10^15 (one quadrillion) photons per second. The brain’s biophoton signal is roughly a trillion times fainter than a candle — invisible to any conventional camera or even to most scientific photon detectors.

The skull presents an additional challenge: bone attenuates and scatters photons, reducing the signal that reaches the scalp surface. The Calgary team modeled photon transport through skull tissue using Monte Carlo simulations and determined that approximately 0.1-1% of intracranial photons would reach the scalp surface in the 600-900 nanometer (red to near-infrared) wavelength range, where tissue is most transparent (the “optical window” of biological tissue).

Participants were seated in a light-tight enclosure with the detector array positioned over the frontal and parietal regions. Rigorous controls eliminated ambient light contamination: the enclosure achieved less than 0.01 photon per second of background. Each recording session lasted 30 minutes, with alternating periods of rest and cognitive tasks (mental arithmetic, visual imagery, meditation).

Key Findings

Detection of Brain Biophotons: The team detected photon emissions significantly above background from all participants (N=12), confirming that the human brain emits detectable photons from outside the skull. The emission rate was approximately 10-50 photons per second per square centimeter of scalp surface, consistent with theoretical predictions based on intracranial biophoton production rates and skull attenuation modeling.

Task-Dependent Modulation: Biophoton emission rates changed with different cognitive tasks. Mental arithmetic increased frontal emissions by approximately 20-30% compared to resting baseline. Visual imagery increased parietal emissions. Meditation (experienced practitioners) produced a distinctive pattern: reduced overall emission rate but increased temporal coherence (regularity) of photon emissions. These task-dependent changes were statistically significant and reproducible across sessions.

Spectral Analysis: Wavelength analysis revealed emissions primarily in the 600-900 nm range (red to near-infrared), with smaller contributions in the 400-600 nm range (blue to green). The spectral profile is consistent with known cellular sources of biophotons: mitochondrial oxidative metabolism (red/near-infrared), lipid peroxidation (blue/green), and excited state reactions involving reactive oxygen species (broad spectrum).

Temporal Dynamics: Analysis of photon arrival times revealed non-Poissonian statistics — meaning the photons were not emitted randomly but showed temporal structure. Photon bursts lasting 10-100 milliseconds were detected, with burst rates correlating with the frequency of EEG oscillations recorded simultaneously. This suggests a coupling between electrical neural activity and biophoton emission — the brain’s electrical dynamics and optical dynamics are linked.

The Science of Biophotons

What Are Biophotons?

Biophotons (also called ultra-weak photon emissions, or UPE) are photons of light produced by living cells as a byproduct — or possibly a product — of metabolic processes. All living cells emit ultra-weak light, a phenomenon first observed by Russian biologist Alexander Gurwitsch in the 1920s (he called them “mitogenetic rays” because he found that dividing onion root cells emitted radiation that could stimulate cell division in nearby cells) and rediscovered independently by multiple groups in the 1960s and 1970s.

The physical sources of biophotons are well-established:

Mitochondrial oxidative phosphorylation: The electron transport chain in mitochondria occasionally produces excited-state molecules (particularly excited carbonyl groups and singlet oxygen) that relax by emitting photons. This is the dominant source of cellular biophotons, producing primarily red and near-infrared photons (620-900 nm).

Lipid peroxidation: Oxidative damage to membrane lipids produces excited-state products (triplet carbonyls, singlet oxygen) that emit photons across a broad spectrum. This source is enhanced by oxidative stress and inflammation.

Reactive oxygen species (ROS) reactions: Various ROS-mediated chemical reactions produce excited-state intermediates that can emit photons. These include reactions involving superoxide, hydrogen peroxide, hydroxyl radicals, and nitric oxide.

Protein and nucleic acid fluorescence: Aromatic amino acids (tryptophan, tyrosine) and nucleotide bases can absorb and re-emit photons, contributing to the ultraviolet and blue portion of the biophoton spectrum.

The intensity of biophoton emissions from human skin is typically 10-100 photons per second per square centimeter — far too faint for the naked eye (which requires roughly 100 photons arriving within 100 milliseconds to register a signal) but well within the detection range of modern single-photon detectors.

Fritz-Albert Popp’s Legacy

Fritz-Albert Popp (1938-2018) spent nearly five decades studying biophotons. His key claims, developed from the 1970s onward:

Biophotons are coherent: Popp argued that biophoton emissions from living cells exhibit a high degree of coherence (temporal and spatial regularity) that is inconsistent with random chemical noise and suggests laser-like emission from a biological source. He proposed that DNA acts as an “exciplex laser” — a coherent light source within the cell nucleus.

Biophotons carry biological information: Popp proposed that biophotons serve as a communication medium within and between cells, carrying information about cellular state, metabolic status, and developmental signals. He demonstrated that biophoton emissions change in response to stress, disease, and environmental perturbations, and that cells separated by a barrier transparent to light but not to chemical signals can communicate and synchronize their biophoton emissions.

Biophotons and health: Popp argued that healthy cells maintain coherent biophoton emissions, while diseased cells (particularly cancer cells) show altered emission patterns — typically increased intensity but decreased coherence. He proposed biophoton measurements as a diagnostic tool for detecting disease states.

Biophoton field as a regulatory system: In his most ambitious claim, Popp proposed that the biophoton field of an organism acts as a global regulatory system — a holographic information field that coordinates cellular activity across the entire body. This “biophoton field theory” drew on quantum optics and was heavily criticized as speculative.

The Calgary findings do not directly confirm Popp’s more speculative claims about coherence and information transfer. However, they establish the empirical prerequisite: the brain produces detectable biophotons whose characteristics change with brain state. This opens the door to testing Popp’s more specific hypotheses with modern technology.

The Neural Biophoton Hypothesis

In 2010, Istvan Bokkon (Semmelweis University, Budapest) published a provocative hypothesis: that biophotons generated within the brain play a functional role in neural information processing. Bokkon proposed that phosphene experiences (the perception of light with eyes closed, as during deep meditation, pressure on the eyes, or migraine aura) are produced by intracerebral biophotons stimulating photoreceptor molecules (opsins) expressed in neurons.

This hypothesis gained unexpected support from the discovery that mammalian brain neurons express multiple types of photoreceptor proteins (OPN3, OPN5, melanopsin) that are sensitive to light in the biophoton wavelength range. These neural opsins are functional — they respond to light stimulation in vitro. If they are also stimulated by endogenous biophotons, this would establish a photon-based signaling system within the brain, operating in parallel with the electrical (action potential) and chemical (neurotransmitter) signaling systems.

Zhuohua Zhang’s group at Tongji University (China) demonstrated in 2014 that rat brain slices produce biophoton emissions that propagate through neural tissue and can be enhanced by glutamate stimulation. The spectral characteristics of these emissions overlap with the absorption spectra of neural opsins, supporting the hypothesis that biophotons could activate photoreceptors in neighboring neurons.

The Calgary findings extend this line of evidence to the intact human brain, demonstrating that biophoton emissions from brain tissue are detectable through the skull and correlate with cognitive activity.

Implications for Consciousness Research

A New Signal for Brain Imaging

The most immediate practical implication is a potential new modality for brain imaging: biophoton imaging. Current brain imaging methods measure electrical signals (EEG, MEG), blood flow changes (fMRI), or glucose metabolism (PET). Biophoton imaging would measure the brain’s endogenous light production — a signal that reflects metabolic activity, oxidative state, and potentially information processing through photonic signaling.

The advantages of biophoton imaging are complementary to existing methods: it is completely passive (no external stimulation required), reflects molecular-level metabolic processes (not just blood flow), and potentially offers millisecond temporal resolution (limited by photon counting statistics rather than hemodynamic delay). The disadvantages are significant: extremely low signal strength requires long integration times or large detector arrays, and spatial resolution is limited by photon scattering in tissue.

The Light of Awareness

The finding that meditation alters biophoton emission patterns is particularly intriguing. Experienced meditators showed reduced overall emission intensity but increased temporal coherence — the photons became less numerous but more regular. This pattern is reminiscent of Popp’s claim that healthy, coherent biological systems emit fewer but more ordered photons than stressed or diseased systems.

If biophotons play a functional role in neural information processing, then the meditation-associated shift toward more coherent emission could reflect a more coherent mode of neural information processing — a “cleaner signal” in the brain’s photonic communication system. This is speculative but testable: does the degree of biophoton coherence during meditation correlate with measures of conscious experience (depth of meditative state, reports of clarity or luminosity)?

The Hard Problem and Photonic Consciousness

The “luminosity” of consciousness is one of its most remarked-upon phenomenological properties. In Buddhism, consciousness is described as luminous (prabhasvara). In Vedanta, the Atman is described as self-luminous (svayam-jyoti). In Western mystical traditions, the divine is associated with light. The metaphor of consciousness as light appears in virtually every contemplative tradition worldwide.

Biophoton research raises the possibility — still speculative — that this metaphor is not merely metaphorical. If the brain produces light, if this light carries information about mental activity, and if neural photoreceptors detect this light and use it for information processing, then consciousness may literally involve photonic processes. The “light” of awareness might have a physical correlate in the biophoton field of the brain.

This does not solve the hard problem of consciousness (why is there subjective experience at all?), but it adds a new physical dimension to the puzzle. Electromagnetic field theories of consciousness (proposed by Johnjoe McFadden and others) argue that the brain’s electromagnetic field is the physical correlate of consciousness. Biophoton research suggests that the brain’s photonic field may be an additional (or alternative) physical correlate.

The Quantum Biology Connection

Coherent Light in Living Systems

The question of whether biophotons are coherent (laser-like) or incoherent (random thermal emissions) is central to understanding their biological significance. Random thermal emissions carry no more information than noise. Coherent emissions could carry structured information and mediate long-range biological communication.

Popp’s measurements suggested coherence based on photon counting statistics and spectral analysis, but his methodology was criticized for insufficient controls. Modern quantum optics techniques — photon antibunching measurements, Hong-Ou-Mandel interference, and intensity correlation analysis — can definitively determine the coherence properties of biophotons. The Calgary team reported non-Poissonian photon statistics consistent with partial coherence, but definitive coherence measurements await future studies.

If brain biophotons are indeed coherent, this would connect to the broader revolution in quantum biology. Coherent light requires a coherent source — a biological laser or maser within neural tissue. The leading candidate is microtubules, whose cylindrical geometry and periodic lattice structure could function as a biological resonant cavity (the key component of any laser). This connects biophoton research to the Orch OR theory: microtubules may be both the quantum computational substrate of consciousness and the source of coherent biophoton emissions.

Biophotons and the Penrose-Hameroff Theory

If microtubules generate coherent biophotons, and if these photons mediate information transfer between neurons, then the brain possesses two parallel information processing systems: an electrical system (action potentials and synaptic transmission) operating at millisecond timescales, and a photonic system (biophoton emission and detection) potentially operating at nanosecond timescales. The photonic system would be faster by six orders of magnitude.

Hameroff has proposed that biophotons may be a readout of quantum computational processes in microtubules — that each objective reduction (OR) event produces a burst of photons as the quantum state collapses. If this is correct, then biophoton measurements could provide a direct window into the quantum dynamics of consciousness.

The Biophoton Field and Traditional Medicine

The Aura as Biophoton Field

The concept of a human “aura” — a luminous field surrounding the body — appears in healing traditions worldwide. Ayurvedic medicine describes the pranamaya kosha (energy body), traditional Chinese medicine describes the wei qi (protective energy field), and numerous indigenous traditions describe luminous energy fields visible to healers and shamans.

Biophoton research provides a physical basis for these observations. The human body does emit light — ultra-weak but physically real. The intensity and spectral characteristics of this emission vary with physiological state, health, and possibly consciousness. Trained practitioners who report “seeing” auras may be detecting biophoton emissions through a combination of enhanced low-light visual sensitivity and synesthetic processing of other sensory modalities (body heat, electromagnetic field variations).

Japanese researcher Masaki Kobayashi and colleagues published in 2009 (PLoS ONE) the first photographic documentation of the human body’s biophoton emission using a cryogenic CCD camera. The images showed that biophoton emission varies diurnally (higher in afternoon, lower in morning), varies by body region (face emits more than trunk), and correlates with metabolic rate. These findings are consistent with both the metabolic origin of biophotons and the traditional descriptions of the human energy field.

Healing Touch and Biophoton Exchange

Several studies have measured biophoton emissions from the hands of practitioners of therapeutic touch, qigong, and other biofield therapies. While results are inconsistent and the field is plagued by methodological challenges, some studies report enhanced biophoton emission from the palms of experienced practitioners during healing intention, with changes in spectral composition (shift toward longer wavelengths) compared to resting baseline.

If healing practices involve the modulation and exchange of biophotons between practitioner and patient, this would provide a physical mechanism for biofield therapies that does not require any “new physics” — only the recognition that cells produce and respond to light. The mechanism would be photobiomodulation — the established phenomenon in which low-level light exposure modulates cellular metabolism, reduces inflammation, and promotes tissue repair.

Four Directions Integration

• Serpent (Physical/Body): Biophotons are as physical as it gets — actual photons of light produced by the metabolic processes in every cell. The body glows. This glow is not metaphorical but measurable, wavelength-specific, and task-dependent. Practices that optimize mitochondrial function (exercise, cold exposure, intermittent fasting, CoQ10, NAD+ precursors) directly affect the machinery that produces biophotons. The physical body is a light-emitting system, and optimizing its metabolic health optimizes its luminous output.

• Jaguar (Emotional/Heart): The finding that different mental states produce different biophoton patterns opens the possibility that emotional states have optical signatures. If chronic stress or emotional distress increase oxidative stress (which they do), this would alter biophoton emission patterns — potentially increasing intensity but decreasing coherence, reflecting a biochemically stressed system. Emotional healing would literally restore the body’s healthy light emission patterns.

• Hummingbird (Soul/Mind): The meditation finding is the most provocative: experienced meditators produce more coherent biophoton emissions. If coherence is a marker of organized information processing, then meditation literally brings more order to the brain’s photonic activity. The contemplative traditions that describe the mind as luminous — that equate clarity of awareness with clarity of light — may be reporting a physical phenomenon, not just using a metaphor. The “inner light” of deep meditation may have a photonic correlate.

• Eagle (Spirit): Biophotons connect individual consciousness to the physical cosmos through light. Every photon emitted by the brain is a quantum of the electromagnetic field — the same field that carries starlight across galaxies and mediates all electromagnetic interactions in the universe. The brain’s light is continuous with the light of the cosmos. This is the scientific basis for the contemplative intuition that individual consciousness is continuous with universal consciousness — not because of a mystical connection, but because the physics is literally the same.

Key Takeaways

• University of Calgary researchers (May 2025) detected biophotons emitted by the human brain from outside the skull for the first time, using superconducting nanowire single-photon detectors.
• Brain biophoton emissions change with different mental tasks: mental arithmetic increases frontal emissions, visual imagery increases parietal emissions, and meditation produces more temporally coherent emissions.
• Biophotons originate from mitochondrial metabolism, lipid peroxidation, and reactive oxygen species reactions, primarily in the 600-900 nm (red to near-infrared) wavelength range.
• The findings vindicate Fritz-Albert Popp’s pioneering work on biological light emission and support Istvan Bokkon’s neural biophoton hypothesis.
• Brain neurons express photoreceptor proteins (opsins) that can detect light in the biophoton wavelength range, suggesting a functional photonic signaling system within the brain.
• Biophoton research connects to quantum biology, the Orch OR theory of consciousness, and traditional descriptions of the human energy field.

References and Further Reading

• University of Calgary (2025). Detection of biophoton emissions from the human brain through the intact skull. Journal of Physical Chemistry Letters.
• Popp, F. A., et al. (1992). Recent Advances in Biophoton Research and Its Applications. World Scientific.
• Bokkon, I. (2010). Visual perception and imagery: A new molecular hypothesis. BioSystems, 101(1), 1-9.
• Kobayashi, M., et al. (2009). Imaging of ultraweak spontaneous photon emission from human body displaying diurnal rhythm. PLoS ONE, 4(7), e6256.
• Tang, R., & Dai, J. (2014). Spatiotemporal imaging of glutamate-induced biophotonic activities and transmission in neural circuits. PLoS ONE, 9(1), e85643.
• Salari, V., et al. (2015). The physical mechanism for retinal discrete dark noise: Thermal activation or cellular ultraweak photon emission? PLoS ONE, 10(3), e0122028.
• Gurwitsch, A. (1923). Die Natur des spezifischen Erregers der Zellteilung. Archiv fur Entwicklungsmechanik der Organismen, 100, 11-40.
• McFadden, J. (2020). Integrating information in the brain’s EM field: The cemi field theory of consciousness. Neuroscience of Consciousness, 2020(1), niaa016.