Cracking your knuckles does not actually hurt your bones or cause arthritis. The sound you hear is just gas bubbles bursting.
18
Sound travels about 4 times faster in water than in air.
408
Unconsciousness will occur after 8-10 seconds after loss of blood supply to the brain.
93
Brain freeze is caused by the brain sensing the drop of temperature on your palate and increasing blood pressure in an attempt to save you from freezing.
14
Scientists concluded that the chicken came first, not the egg, because the protein which makes the egg shells is only produced by hens.
11
It would take more than 150 years to drive a car to the sun.
569