If you mouth the word "colorful" to someone, it looks like you are saying "I love you".
634
You can hear the blood flowing through your ears if you find a quiet place and cover them tightly.
19
Caffeine boosts memory.
405
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


