For most people alive today, a “good night’s sleep” means roughly eight uninterrupted hours in a dark room, followed by a single morning wake-up. Yet historical evidence suggests that this pattern is ...

Some years ago, I read Roger Ekirch’s At Day’s Close, a book about the history of sleep. Ekirch discovered that before the arrival of artificial light, English people had customarily had two sleep ...

There are two very different traditions about the value of sleep in productivity. Thomas Edison (1847-1931), whose lifetime of inventions changed the world, believed that sleep was an idle activity ...