Humans glow in the dark — just too faintly to see
Chemical reactions in our cells give off a tiny amount of visible light, about a thousand times weaker than the eye can detect. It is strongest in the late afternoon.
More human body facts
See all →Your body makes about 2 million red blood cells every second
Bone marrow produces them continuously because each red cell lives only around 120 days. The total in your body is roughly 25 trillion.
Read the fact →Your stomach gets a new lining every few days
Stomach acid is strong enough to dissolve metal, so the cells lining the stomach are replaced roughly every three to four days before the acid can damage them.
Read the fact →Babies are born with about 300 bones; adults have 206
Many of a newborn’s bones are separate pieces of cartilage that fuse together as the child grows, so the count drops as the skeleton hardens.
Read the fact →