Staying awake for 17 hours is the same for your body as drinking 2 glasses of wine.
193
Yawns are more contagious among people with closer relationships.
163
Your thumb is about the same size as your nose.
124
Cracking your knuckles does not actually hurt your bones or cause arthritis. The sound you hear is just gas bubbles bursting.
18
Enamel is hardest substance in the human body.
61
Chewing gum boosts your brain power.
285
The human brain is very soft, having a consistency similar to soft gelatin or firm tofu.
13