Cracking your knuckles does not actually hurt your bones or cause arthritis. The sound you hear is just gas bubbles bursting.
18
The human brain doesn't stop developing until about 25 years old.
102
Your thumb is about the same size as your nose.
124
The average person's skin weighs twice as much as their brain.
131
The human brain uses approximately as much energy as a 10 watt light bulb.
120
If your DNA was stretched out it would reach to the moon 6,000 times.
256
For most people, no matter how hard you pinch the skin on your elbow with your fingers it doesn't hurt.
515
If you are cold you are more likely to be hungry because you use energy to keep warm.
143