The human brain doesn't stop developing until about 25 years old.
102
It took 200,000 years for humans to reach 3 billion in number. It took 40 years for the next 3 billion.
11
Every human spent about half an hour as a single cell.
144
It takes about 20 seconds for a red blood cell to circle the whole body.
102
Human hair and fingernails continue to grow after death.
7
Having sex can make a woman look younger and more attractive due to the release of estrogen and collagen.
346
An unprotected human can survive up to 1.5 minutes in space with no permanent bodily damage.
82
The world's shortest man measures only 21.5 inches.
73