Cracking your knuckles does not actually hurt your bones or cause arthritis. The sound you hear is just gas bubbles bursting.
18
Poor eyesight (myopia) is associated with higher IQ.
232
Our eyes are always the same size from birth, but our nose and ears never stop growing.
266
For most people, no matter how hard you pinch the skin on your elbow with your fingers it doesn't hurt.
515
The human body contains over a billion miles of DNA.
147
The average person's skin weighs twice as much as their brain.
131
The largest cell in the human body is the female egg and the smallest is the male sperm.
682