**Scientists Reveal Humans Emit Subtle Glow Signalling Life, Which Vanishes at Death**
A team of researchers from the University of Calgary, Canada, has illuminated a curious feature of living organisms: all living humans continuously release a faint glow, which ceases completely at the moment of death. This intriguing phenomenon, commonly referred to as ‘ultraweak photon emissions’ (UPE), has now been visualised thanks to cutting-edge imaging equipment designed to detect light at extremely low intensities.
The research, led by physicist Vahid Salari, provides a rare glimpse inside the biochemical engine that powers living cells. “UPE is closely linked to vitality,” Dr Salari stated, explaining that these photon emissions are an inevitable byproduct of the chemical reactions that keep organisms alive. While invisible to the naked eye, the emissions can be captured with highly sensitive cameras operating in an ultra-dark environment.
The innovative experiments involved both plant life and animal models. For study purposes, the scientists placed specimens in an environment completely absent of external light interference, allowing even the faintest luminescence to be recorded. When observing living mice, the researchers noted the faint glow persisted as long as the animals were alive, but faded rapidly at the point of death—even before any measurable drop in body temperature.
Interestingly, this phenomenon extends beyond humans. In the case of plants, when subjected to various forms of stress—be it heat, injury, or harsh environmental conditions—the level of emitted photons was observed to rise sharply. The team reported that, in injured leaves, the brightness at damaged sites far exceeded undamaged areas, with this effect persisting for the entirety of their 16-hour imaging sessions.
These observations suggest that UPE could serve as a non-invasive marker for monitoring the health of different life forms. The sharp increase in emission under stress might, for instance, be developed as an early-detection tool for plant diseases or physiological distress in animals and humans. Dr Salari points out that the underlying science could one day allow practitioners to assess vitality or detect metabolic changes simply by monitoring ultraweak photon output.
The scientific roots of UPE research date back over a century. Russian scientist Alexander Gurwitsch was among the first to suggest, in the 1920s, that living organisms emit a form of ‘biophoton’ radiation. He theorised that these rays might enable intercellular communication. Gurwitsch’s pioneering insights earned him the Stalin Prize in 1941, and, decades later, German researcher Fritz-Albert Popp furthered the field by investigating these emissions at the University of Marburg in the 1970s.
Despite being invisible and once only a scientific curiosity, these ‘living lights’ continue to intrigue researchers worldwide. The possibility that such photon emissions may provide a window into cellular behaviour, stress responses, or even broader concepts of vitality is adding a novel layer to our understanding of the living world.
There remains, however, much to uncover. The precise biological purpose—if any—for these photon emissions is still debated among experts. Are they merely a passive end-result of energy processes within cells, or might they serve a more integral role in communication and regulation?
What is increasingly clear is that this faint glow is a universal characteristic of life itself—and its disappearance marks the cessation of biological function. As imaging technology continues to advance, further discoveries in this field may illuminate the mysteries that lie at the heart of life and death.
For now, the work from the University of Calgary adds a fresh perspective and highlights the cutting-edge methods used by scientists as they seek to comprehend the subtle signals that separate living beings from the inanimate world.