Cracking your knuckles does not actually hurt your bones or cause arthritis. The sound you hear is just gas bubbles bursting.
18
Staying awake for 17 hours is the same for your body as drinking 2 glasses of wine.
193
Every year your body replaces 98% of your atoms.
119
Enamel is hardest substance in the human body.
61
The human brain uses approximately as much energy as a 10 watt light bulb.
120
Your heart will pump about 212 million liters in its lifetime.
26
If every muscle in your body could pull in one direction, you could lift nearly 25 tons.
22
For most people, no matter how hard you pinch the skin on your elbow with your fingers it doesn't hurt.
515