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
It takes twice as long to lose new muscle if you stop working out than it did to gain it.
127
Oxygen, carbon, hydrogen and nitrogen make up 90% of the human body.
118
Yawns are more contagious among people with closer relationships.
163
Every year your body replaces 98% of your atoms.
119
The average person's skin weighs twice as much as their brain.
131
Poor eyesight (myopia) is associated with higher IQ.
232