The adult human brain weighs about 3 pounds (1,300-1,400 g).
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Cracking your knuckles does not actually hurt your bones or cause arthritis. The sound you hear is just gas bubbles bursting.
18
The human brain uses approximately as much energy as a 10 watt light bulb.
120
Your body is creating and killing about 2.4 million red blood cells per second.
17
The human brain has the capacity to store everything that you experience.
4k
It takes about 20 seconds for a red blood cell to circle the whole body.
102
When you take a step, you are using up to 200 muscles.
886
For most people, no matter how hard you pinch the skin on your elbow with your fingers it doesn't hurt.
515