For most people, no matter how hard you pinch the skin on your elbow with your fingers it doesn't hurt.
515
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 is very soft, having a consistency similar to soft gelatin or firm tofu.
13
The adult human brain weighs about 3 pounds (1,300-1,400 g).
99
Your body is creating and killing about 2.4 million red blood cells per second.
17
The human brain uses approximately as much energy as a 10 watt light bulb.
120
The average person's skin weighs twice as much as their brain.
131