Cracking your knuckles does not actually hurt your bones or cause arthritis. The sound you hear is just gas bubbles bursting.
18
After age 30, the brain begins to lose about 50,000 neurons per day - shrinking the brain .25% each year.
55
Poor eyesight (myopia) is associated with higher IQ.
232
The largest cell in the human body is the female egg and the smallest is the male sperm.
682
All the chemicals in a human body combined are worth about 6.25 euro (if sold separately).
266
The average person's skin weighs twice as much as their brain.
131
The human body contains over a billion miles of DNA.
147