Cracking your knuckles does not actually hurt your bones or cause arthritis. The sound you hear is just gas bubbles bursting.
18
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
If your DNA was stretched out it would reach to the moon 6,000 times.
256
The human brain has the capacity to store everything that you experience.
4k
The human brain doesn't stop developing until about 25 years old.
102
Your body is creating and killing about 2.4 million red blood cells per second.
17
Your thumb is about the same size as your nose.
124