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
Every year your body replaces 98% of your atoms.
119
Yawns are more contagious among people with closer relationships.
163
Our eyes are always the same size from birth, but our nose and ears never stop growing.
266
The human brain doesn't stop developing until about 25 years old.
102
If your DNA was stretched out it would reach to the moon 6,000 times.
256
The human body contains over a billion miles of DNA.
147