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 uses approximately as much energy as a 10 watt light bulb.
120
The human brain has the capacity to store everything that you experience.
4k
For most people, no matter how hard you pinch the skin on your elbow with your fingers it doesn't hurt.
515
Your thumb is about the same size as your nose.
124
Our eyes are always the same size from birth, but our nose and ears never stop growing.
266
Coughing can cause air to move through your windpipe faster than the speed of sound - over a thousand feet per second!
197
Dogs can be trained to identify the scent of lung cancer long before symptoms develop.
190