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
The human brain uses approximately as much energy as a 10 watt light bulb.
120
One human hair can support 3 ounces.
191
When you get goosebumps and your hair stands, the hair helps to trap air, making you feel warmer by keeping in your body heat.
46
Coughing can cause air to move through your windpipe faster than the speed of sound - over a thousand feet per second!
197
If you are cold you are more likely to be hungry because you use energy to keep warm.
143
Your heart will pump about 212 million liters in its lifetime.
26