Cracking your knuckles does not actually hurt your bones or cause arthritis. The sound you hear is just gas bubbles bursting.
18
It takes about 20 seconds for a red blood cell to circle the whole body.
102
The adult human brain weighs about 3 pounds (1,300-1,400 g).
99
The human brain has the capacity to store everything that you experience.
4k
Quick naps not only improve your alertness, but they also help in decision making, creativity and sensory perception.
149
The human brain doesn't stop developing until about 25 years old.
102
The human brain is very soft, having a consistency similar to soft gelatin or firm tofu.
13
Yawns are more contagious among people with closer relationships.
163