Cracking your knuckles does not actually hurt your bones or cause arthritis. The sound you hear is just gas bubbles bursting.
18
The average person's skin weighs twice as much as their brain.
131
Our eyes are always the same size from birth, but our nose and ears never stop growing.
266
Yawns are more contagious among people with closer relationships.
163
If every muscle in your body could pull in one direction, you could lift nearly 25 tons.
22
The human brain uses approximately as much energy as a 10 watt light bulb.
120
One human hair can support 3 ounces.
191
Your heart will pump about 212 million liters in its lifetime.
26