For most people, no matter how hard you pinch the skin on your elbow with your fingers it doesn't hurt.
515
Cracking your knuckles does not actually hurt your bones or cause arthritis. The sound you hear is just gas bubbles bursting.
18
If every muscle in your body could pull in one direction, you could lift nearly 25 tons.
22
One human hair can support 3 ounces.
191
Chewing gum boosts your brain power.
285
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