Cracking your knuckles does not actually hurt your bones or cause arthritis. The sound you hear is just gas bubbles bursting.
18
The average sperm cell swims at 8 inches per hour.
76
If your DNA was stretched out it would reach to the moon 6,000 times.
256
Our eyes are always the same size from birth, but our nose and ears never stop growing.
266
An Indian man known as "Snake Manu" can put small snakes, including deadly cobras, into his mouth and pass them out through his nose.
59
The human body contains over a billion miles of DNA.
147
An average heart beats 100,000 times a day, pumping some 2,000 gallons of blood through its chambers. Over a 70-year life span, that adds up to more than 2.5 billion heartbeats.
73
After age 30, the brain begins to lose about 50,000 neurons per day - shrinking the brain .25% each year.
55