Your thumb is about the same size as your nose.
124
Cracking your knuckles does not actually hurt your bones or cause arthritis. The sound you hear is just gas bubbles bursting.
18
Every year your body replaces 98% of your atoms.
119
If every muscle in your body could pull in one direction, you could lift nearly 25 tons.
22
The human brain doesn't stop developing until about 25 years old.
102
The human brain uses approximately as much energy as a 10 watt light bulb.
120
It takes twice as long to lose new muscle if you stop working out than it did to gain it.
127
Women have about four times as many foot problems as men; lifelong patterns of wearing high heels often are the culprit.
111