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 thumb is about the same size as your nose.
124
It takes twice as long to lose new muscle if you stop working out than it did to gain it.
127
Our eyes are always the same size from birth, but our nose and ears never stop growing.
266
Staying awake for 17 hours is the same for your body as drinking 2 glasses of wine.
193
After age 30, the brain begins to lose about 50,000 neurons per day - shrinking the brain .25% each year.
55