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
Chewing gum boosts your brain power.
285
When you take a step, you are using up to 200 muscles.
886
If your DNA was stretched out it would reach to the moon 6,000 times.
256
After age 30, the brain begins to lose about 50,000 neurons per day - shrinking the brain .25% each year.
55
The human body contains over a billion miles of DNA.
147
For most people, no matter how hard you pinch the skin on your elbow with your fingers it doesn't hurt.
515