Cracking your knuckles does not actually hurt your bones or cause arthritis. The sound you hear is just gas bubbles bursting.
18
Quick naps not only improve your alertness, but they also help in decision making, creativity and sensory perception.
149
The human brain doesn't stop developing until about 25 years old.
102
Every year your body replaces 98% of your atoms.
119
Your body is creating and killing about 2.4 million red blood cells per second.
17
For most people, no matter how hard you pinch the skin on your elbow with your fingers it doesn't hurt.
515
One human hair can support 3 ounces.
191
Women have about four times as many foot problems as men; lifelong patterns of wearing high heels often are the culprit.
111