Cracking your knuckles does not actually hurt your bones or cause arthritis. The sound you hear is just gas bubbles bursting.
18
Your thumb is about the same size as your nose.
124
The human brain doesn't stop developing until about 25 years old.
102
Enamel is hardest substance in the human body.
61
Our eyes are always the same size from birth, but our nose and ears never stop growing.
266
If your DNA was stretched out it would reach to the moon 6,000 times.
256
Quick naps not only improve your alertness, but they also help in decision making, creativity and sensory perception.
149
For most people, no matter how hard you pinch the skin on your elbow with your fingers it doesn't hurt.
515