Yawns are more contagious among people with closer relationships.
163
After age 30, the brain begins to lose about 50,000 neurons per day - shrinking the brain .25% each year.
55
Enamel is hardest substance in the human body.
61
Cracking your knuckles does not actually hurt your bones or cause arthritis. The sound you hear is just gas bubbles bursting.
18
The adult human brain weighs about 3 pounds (1,300-1,400 g).
99
If every muscle in your body could pull in one direction, you could lift nearly 25 tons.
22
The human brain has the capacity to store everything that you experience.
4k
Every year your body replaces 98% of your atoms.
119