New study shows plants and animals emit a visible light that expires at death

Nature of the light and basic physics

• Commenters stress this is ultraweak photon emission across ~200–1000 nm (UV, visible, near-IR), not something bright enough to see with eyes.
• Several people note that all matter above absolute zero emits EM radiation, but others clarify that this specific signal is not just generic thermal (black‑body) radiation.

Not just “heat”: black‑body vs biological emission

• Multiple replies correct assumptions that this is “just heat.”
• The paper (and preprint) show that mice—kept at the same temperature whether alive or dead—emit different visible-wavelength photons, and the measured spectrum does not match 37°C black‑body radiation.
• Thus the emission is attributed to biochemical processes rather than bulk thermal noise.

Proposed biochemical mechanisms

• Suggested sources include mitochondrial respiratory complexes (I and III), where electron leakage and redox reactions (quinones, flavins, metal centers) can leave molecules in excited states that occasionally relax by emitting photons.
• More generally, commenters note that many exothermic chemical reactions and organic electronic transitions lie in the visible/near‑IR energy range, so weak spontaneous luminescence from metabolism is expected.
• Changes with injury and anesthesia are seen as consistent with altered mitochondrial and metabolic activity.

Life, death, and definitional questions

• The emission fades after death but not instantaneously, raising questions about where to draw a precise life/death boundary.
• Some argue this fade cannot define death, since brain death and continued bodily metabolism (or decapitated tissue temporarily “alive”) complicate things.

Potential applications

• Several people speculate about using this signal for noninvasive diagnostics or “aura scanners” to assess stress, injury, wound healing, or plant health, though ambient light and sensitivity requirements are seen as major obstacles.

Spiritual, “aura,” and consciousness debates

• The finding is seized on by some as possible support for ideas like auras or a “spark of life,” while others strongly push back that the effect is fully explainable by chemistry.
• There is debate over whether anyone could perceive such weak emissions unaided; consensus in the thread is that intensities are far below human visual thresholds.
• A tangent arises about microtubules, quantum theories of consciousness, and whether consciousness “lives” in a specific structure versus emerging from distributed brain activity.

Scale, detectability, and broader context

• Emission rates (order 10–10³ photons·cm⁻²·s⁻¹) are described as extremely low, making detection on exoplanets or planetary scale impossible with foreseeable technology.
• Some note that with sufficiently sensitive instruments, differences between living, stressed, and dead matter in many modalities (light, sound, etc.) are unsurprising.