WHY READ THIS ARTICLE?
Delve into the mystery of why you sleep for a third of your life.
Learn about scientists’ experiments to reveal the original function of sleep.
Night is falling in California. In a laboratory aquarium, a jellyfish holds its position just above the aquarium’s floor, using pulsating motions for lift. Two students are watching the primitive creature closely, counting each contraction of the jellyfish body. As darkness falls, the motions slow: the jellyfish seems to have fallen asleep.
But the students are not there just to count: they are also depriving the jellyfish of sleep. Every time the creature seems todozes off, they wake it up again with artificial waves in the aquarium – and they continue to do so all night long.
The next day, they continue to watch the jellyfish, which is clearly feeling the effects of its restless night. The lack of sleep has made its
