Cracking your knuckles does not actually hurt your bones or cause arthritis. The sound you hear is just gas bubbles bursting.
18
After age 30, the brain begins to lose about 50,000 neurons per day - shrinking the brain .25% each year.
55
For most people, no matter how hard you pinch the skin on your elbow with your fingers it doesn't hurt.
515
If you are cold you are more likely to be hungry because you use energy to keep warm.
143
Our eyes are always the same size from birth, but our nose and ears never stop growing.
266
The average person's skin weighs twice as much as their brain.
131
The human brain has the capacity to store everything that you experience.
4k
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