Human hands glow, but fingernails release the most light, according to a study that found all parts of the hand emit detectable levels of light.
The findings support prior research that suggested most living things, including plants, release light. Since disease and illness appear to affect the strength and pattern of the glow, the discovery might lead to less-invasive ways of diagnosing patients.
Mitsuo Hiramatsu, a scientist at the Central Research Laboratory at Hamamatsu Photonics in Japan, who led the research, told Discovery News that the hands are not the only parts of the body that shine light by releasing photons, or tiny, energized increments of light.
“Not only the hands, but also the forehead and bottoms of our feet emit photons,” Hiramatsu said, and added that in terms of hands “the presence of photons means that our hands are producing light all of the time.”