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
Oxygen, carbon, hydrogen and nitrogen make up 90% of the human body.
118
Coughing can cause air to move through your windpipe faster than the speed of sound - over a thousand feet per second!
197
Women have about four times as many foot problems as men; lifelong patterns of wearing high heels often are the culprit.
111
An Indian man known as "Snake Manu" can put small snakes, including deadly cobras, into his mouth and pass them out through his nose.
59
The human brain doesn't stop developing until about 25 years old.
102
The human brain has the capacity to store everything that you experience.
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