Cracking your knuckles does not actually hurt your bones or cause arthritis. The sound you hear is just gas bubbles bursting.
18
The average sperm cell swims at 8 inches per hour.
76
If your DNA was stretched out it would reach to the moon 6,000 times.
256
Poor eyesight (myopia) is associated with higher IQ.
232
Yawns are more contagious among people with closer relationships.
163
Your thumb is about the same size as your nose.
124
An average heart beats 100,000 times a day, pumping some 2,000 gallons of blood through its chambers. Over a 70-year life span, that adds up to more than 2.5 billion heartbeats.
73
Quick naps not only improve your alertness, but they also help in decision making, creativity and sensory perception.
149