Why Do We Need to Sleep?
February 12, 2018 4:33 AM Subscribe
Biologists call this need “sleep pressure”: Stay up too late, build up sleep pressure. Feeling drowsy in the evenings? Of course you are—by being awake all day, you’ve been generating sleep pressure! But like “dark matter,” this is a name for something whose nature we do not yet understand. The more time you spend thinking about sleep pressure, the more it seems like a riddle game out of Tolkien: What builds up over the course of wakefulness, and disperses during sleep? Is it a timer? A molecule that accrues every day and needs to be flushed away? What is this metaphorical tally of hours, locked in some chamber of the brain, waiting to be wiped clean every night? [slAtlantic]