Cracking your knuckles does not actually hurt your bones or cause arthritis. The sound you hear is just gas bubbles bursting.
18
Oxygen, carbon, hydrogen and nitrogen make up 90% of the human body.
118
Poor eyesight (myopia) is associated with higher IQ.
232
All the chemicals in a human body combined are worth about 6.25 euro (if sold separately).
266
Every year your body replaces 98% of your atoms.
119
The average sperm cell swims at 8 inches per hour.
76
Dogs can be trained to identify the scent of lung cancer long before symptoms develop.
190
There are times when you're walking that the pressure on your feet exceeds your body weight, and when you're running, it can be three or four times your weight.
62