Cracking your knuckles does not actually hurt your bones or cause arthritis. The sound you hear is just gas bubbles bursting.
18
When you take a step, you are using up to 200 muscles.
886
Poor eyesight (myopia) is associated with higher IQ.
232
The average person's skin weighs twice as much as their brain.
131
Your body is creating and killing about 2.4 million red blood cells per second.
17
One human hair can support 3 ounces.
191
An Indian man known as "Snake Manu" can put small snakes, including deadly cobras, into his mouth and pass them out through his nose.
59