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
Cats have a weak sense of taste. They have only 473 tastebuds, humans have 9,000.
307
Pain occurs when sounds are above 130 db.
124
The world's shortest man measures only 21.5 inches.
73
You can't tickle yourself.
29
There are times when you're walking that the pressure on your feet exceeds your body weight, and when you're running, it can be three or four times your weight.
62
The human brain uses approximately as much energy as a 10 watt light bulb.
120
It takes about 20 seconds for a red blood cell to circle the whole body.
102