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 adult human brain weighs about 3 pounds (1,300-1,400 g).
99
An Indian man known as "Snake Manu" can put small snakes, including deadly cobras, into his mouth and pass them out through his nose.
59
Our eyes are always the same size from birth, but our nose and ears never stop growing.
266
There are times when you're walking that the pressure on your feet exceeds your body weight, and when you're running, it can be three or four times your weight.
62
The human brain uses approximately as much energy as a 10 watt light bulb.
120
