Blue light fends off drowsiness in the middle of the night, which could be useful to people who work at night.
240
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
Staying awake for 17 hours is the same for your body as drinking 2 glasses of wine.
193
The record for the longest scientifically documented period without sleep is 264.4 hours (eleven days).
15
Cows can sleep standing up, but they can only dream lying down.
745
You forget 90% of your dreams.
256
The strangers in your dreams are actually people that you've seen in real life.
50