Cracking your knuckles does not actually hurt your bones or cause arthritis. The sound you hear is just gas bubbles bursting.
18
The largest cell in the human body is the female egg and the smallest is the male sperm.
682
Chewing gum boosts your brain power.
285
Our eyes are always the same size from birth, but our nose and ears never stop growing.
266
It takes twice as long to lose new muscle if you stop working out than it did to gain it.
127
Poor eyesight (myopia) is associated with higher IQ.
232
The average sperm cell swims at 8 inches per hour.
76
Your body is creating and killing about 2.4 million red blood cells per second.
17