The world's shortest man measures only 21.5 inches.
73
Modern humans first appeared about 200,000 years ago, but record keeping didn't begin until about 6,000 years ago. That means about 97% of human history is lost.
21
The human brain is more active during sleep than during the day.
28
The average sperm cell swims at 8 inches per hour.
4
When you are looking at someone you love, your pupils dilate, they do the same when you are looking at someone you hate.
1k
Some monks can increase their body temperature so much they can dry soaking sheets in a freezing room!
31
It took 200,000 years for humans to reach 3 billion in number. It took 40 years for the next 3 billion.
11