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
After age 30, the brain begins to lose about 50,000 neurons per day - shrinking the brain .25% each year.
55
The adult human brain weighs about 3 pounds (1,300-1,400 g).
99
All the chemicals in a human body combined are worth about 6.25 euro (if sold separately).
266
There are times when you're walking that the pressure on your feet exceeds your body weight, and when you're running, it can be three or four times your weight.
62
Quick naps not only improve your alertness, but they also help in decision making, creativity and sensory perception.
149
The human brain uses approximately as much energy as a 10 watt light bulb.
120