Blue light fends off drowsiness in the middle of the night, which could be useful to people who work at night.
240
Sleeping on your stomach can induce weirder, scarier, and sexier dreams.
22
Some people have a "natural alarm clock" allowing them to wake up when they want. This is actually caused by a burst of the stress hormone adrenocorticotropin.
15
The human brain is more active during sleep than during the day.
28
You burn more calories sleeping than you do watching television.
348
Staying awake for 17 hours is the same for your body as drinking 2 glasses of wine.
193