Living things glow with visible light


Japanese scientist have shown how the human body glows with visible light. The quantity of light emitted is 1000 times too dim for our eyes to see, but the researchers imaged the glow with special cameras. The light is tied to metabolism, suggesting that measuring it could have medical applications, says Tohoku Institute of Technology scientist Masaki Kobayashi. Meanwhile, New Age aura-seers everywhere scream with "vindication." From LiveScience:

In fact, virtually all living creatures emit very weak light, which is thought to be a byproduct of biochemical reactions involving free radicals.

(This visible light differs from the infrared radiation — an invisible form of light — that comes from body heat.)

To learn more about this faint visible light, scientists in Japan employed extraordinarily sensitive cameras capable of detecting single photons. Five healthy male volunteers in their 20s were placed bare-chested in front of the cameras in complete darkness in light-tight rooms for 20 minutes every three hours from 10 a.m. to 10 p.m. for three days.

The researchers found the body glow rose and fell over the day, with its lowest point at 10 a.m. and its peak at 4 p.m., dropping gradually after that. These findings suggest there is light emission linked to our body clocks, most likely due to how our metabolic rhythms fluctuate over the course of the day.

"Strange! Humans Glow in Visible Light" (Thanks, Marina Gorbis!)