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
Coughing can cause air to move through your windpipe faster than the speed of sound - over a thousand feet per second!
197
When you take a step, you are using up to 200 muscles.
886
Chewing gum boosts your brain power.
285
Yawns are more contagious among people with closer relationships.
163
Our eyes are always the same size from birth, but our nose and ears never stop growing.
266