Published in respected UK newspaper, the Guardian
Writing in the online journal PLoS ONE, the researchers describe how they imaged volunteers' upper bodies using ultra-sensitive cameras over a period of several days. Their results show that the amount of light emitted follows a 24-hour cycle, at its highest in late afternoon and lowest late at night, and that the brightest light is emitted from the cheeks, forehead and neck.
Strangely, the areas that produced the brightest light did not correspond with the brightest areas on thermal images of the volunteers' bodies.
Bioluminescence is a side-effect of metabolic reactions within all creatures, the result of highly reactive free radicals produced through cell respiration interacting with free-floating lipids and proteins. The "excited" molecules that result can react with chemicals called fluorophores to emit photons.
Human bioluminescence has been suspected for years, but until now the cameras required to detect such dim light sources took over an hour to capture a single image and so were unable to measure the constantly fluctuating light from living creatures.
Writing in the online journal PLoS ONE, the researchers describe how they imaged volunteers' upper bodies using ultra-sensitive cameras over a period of several days. Their results show that the amount of light emitted follows a 24-hour cycle, at its highest in late afternoon and lowest late at night, and that the brightest light is emitted from the cheeks, forehead and neck.
Strangely, the areas that produced the brightest light did not correspond with the brightest areas on thermal images of the volunteers' bodies.
The light is 1000 times weaker than the human eye can perceive. At such a low level, it is unlikely to serve any evolutionary purpose in humans – though when emitted more strongly by animals such as fireflies, glow-worms and deep-sea fish, it can be used to attract mates and for illumination.
Bioluminescence is a side-effect of metabolic reactions within all creatures, the result of highly reactive free radicals produced through cell respiration interacting with free-floating lipids and proteins. The "excited" molecules that result can react with chemicals called fluorophores to emit photons.
Human bioluminescence has been suspected for years, but until now the cameras required to detect such dim light sources took over an hour to capture a single image and so were unable to measure the constantly fluctuating light from living creatures.
... And now the original version in technical geek speak from the "Peer Reviewed Science" publication PLoS One
Imaging of Ultraweak Spontaneous Photon Emission from Human Body Displaying Diurnal Rhythm
he human body literally glimmers. The intensity of the light emitted by the body is 1000 times lower than the sensitivity of our naked eyes. Ultraweak photon emission is known as the energy released as light through the changes in energy metabolism. We successfully imaged the diurnal change of this ultraweak photon emission with an improved highly sensitive imaging system using cryogenic charge-coupled device (CCD) camera. We found that the human body directly and rhythmically emits light. The diurnal changes in photon emission might be linked to changes in energy metabolism.