Cracking your knuckles does not actually hurt your bones or cause arthritis. The sound you hear is just gas bubbles bursting.
18
The adult human brain weighs about 3 pounds (1,300-1,400 g).
99
The human brain uses approximately as much energy as a 10 watt light bulb.
120
Staying awake for 17 hours is the same for your body as drinking 2 glasses of wine.
193
Chewing gum boosts your brain power.
285
The human body contains over a billion miles of DNA.
147
The human brain doesn't stop developing until about 25 years old.
102
If every muscle in your body could pull in one direction, you could lift nearly 25 tons.
22