Cracking your knuckles does not actually hurt your bones or cause arthritis. The sound you hear is just gas bubbles bursting.
18
Yawns are more contagious among people with closer relationships.
163
If you are cold you are more likely to be hungry because you use energy to keep warm.
143
Chewing gum boosts your brain power.
285
Coughing can cause air to move through your windpipe faster than the speed of sound - over a thousand feet per second!
197
The human body contains over a billion miles of DNA.
147
If your DNA was stretched out it would reach to the moon 6,000 times.
256
There are times when you're walking that the pressure on your feet exceeds your body weight, and when you're running, it can be three or four times your weight.
62