Cracking your knuckles does not actually hurt your bones or cause arthritis. The sound you hear is just gas bubbles bursting.
18
It takes about 20 seconds for a red blood cell to circle the whole body.
102
The human brain has the capacity to store everything that you experience.
4k
Your body is creating and killing about 2.4 million red blood cells per second.
17
When you take a step, you are using up to 200 muscles.
886
Staying awake for 17 hours is the same for your body as drinking 2 glasses of wine.
193
Yawns are more contagious among people with closer relationships.
163