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 doesn't stop developing until about 25 years old.
102
The human body contains over a billion miles of DNA.
147
The human brain uses approximately as much energy as a 10 watt light bulb.
120
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
Dogs can be trained to identify the scent of lung cancer long before symptoms develop.
190
The human brain is very soft, having a consistency similar to soft gelatin or firm tofu.
13
Poor eyesight (myopia) is associated with higher IQ.
232