Coughing can cause air to move through your windpipe faster than the speed of sound - over a thousand feet per second!
197
Cracking your knuckles does not actually hurt your bones or cause arthritis. The sound you hear is just gas bubbles bursting.
18
It takes about 20 seconds for a red blood cell to circle the whole body.
102
Your thumb is about the same size as your nose.
124
The human brain uses approximately as much energy as a 10 watt light bulb.
120
Chewing gum boosts your brain power.
285
Our eyes are always the same size from birth, but our nose and ears never stop growing.
266
One human hair can support 3 ounces.
191