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
Our eyes are always the same size from birth, but our nose and ears never stop growing.
266
The human brain is very soft, having a consistency similar to soft gelatin or firm tofu.
13
For most people, no matter how hard you pinch the skin on your elbow with your fingers it doesn't hurt.
515
If your DNA was stretched out it would reach to the moon 6,000 times.
256
Quick naps not only improve your alertness, but they also help in decision making, creativity and sensory perception.
149
The human brain uses approximately as much energy as a 10 watt light bulb.
120