Cracking your knuckles does not actually hurt your bones or cause arthritis. The sound you hear is just gas bubbles bursting.
18
If your DNA was stretched out it would reach to the moon 6,000 times.
256
Our eyes are always the same size from birth, but our nose and ears never stop growing.
266
An average heart beats 100,000 times a day, pumping some 2,000 gallons of blood through its chambers. Over a 70-year life span, that adds up to more than 2.5 billion heartbeats.
73
The human brain is very soft, having a consistency similar to soft gelatin or firm tofu.
13
When you take a step, you are using up to 200 muscles.
885
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