Cracking your knuckles does not actually hurt your bones or cause arthritis. The sound you hear is just gas bubbles bursting.
18
Your body is creating and killing about 2.4 million red blood cells per second.
17
Poor eyesight (myopia) is associated with higher IQ.
232
The human brain doesn't stop developing until about 25 years old.
102
It takes about 20 seconds for a red blood cell to circle the whole body.
102
Most of us have microscopic, worm like mites named Demodex that live in our eyelashes and have claws and a mouth.
-137
It takes twice as long to lose new muscle if you stop working out than it did to gain it.
127
The human brain uses approximately as much energy as a 10 watt light bulb.
120