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
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
Pet dogs and elephants are the only animals that seem to instinctively understand human gesture.
14
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
Enamel is hardest substance in the human body.
61
Coughing can cause air to move through your windpipe faster than the speed of sound - over a thousand feet per second!
197