Cracking your knuckles does not actually hurt your bones or cause arthritis. The sound you hear is just gas bubbles bursting.
18
The human brain doesn't stop developing until about 25 years old.
102
When you get goosebumps and your hair stands, the hair helps to trap air, making you feel warmer by keeping in your body heat.
46
Your body is creating and killing about 2.4 million red blood cells per second.
17
One human hair can support 3 ounces.
191
If you are cold you are more likely to be hungry because you use energy to keep warm.
143
Women have about four times as many foot problems as men; lifelong patterns of wearing high heels often are the culprit.
111
Coughing can cause air to move through your windpipe faster than the speed of sound - over a thousand feet per second!
197