You glow in the dark. Right now. So does every other human on Earth. The reason you don’t see it is that the light is incredibly faint - about a thousand times dimmer than what human eyes can perceive. Special ultra-sensitive cameras in pitch-black laboratories have captured it: a soft, ghostly glow coming off every part of the human body.
The light comes from cellular metabolism. When cells burn fuel and produce energy, they sometimes release tiny photons of light as a byproduct. Cells throughout the body do this. The brightness varies through the day - research has found that human “biophoton” emission peaks in late afternoon and is dimmest in the early morning. The face emits more light than other body parts, partly because more chemical activity is happening there.
So if you took a photo with a sensitive enough camera in a perfectly dark room, you’d see yourself softly glowing. Unfortunately, the equipment that can detect biophotons is expensive and rare, and your own eyes will never adapt to that level of low light. We’re walking light bulbs - we just can’t see ourselves.
