Dreamland: Adventures in the Strange Science of Sleep

In 1994, an earthquake knocked out electricity in Los Angeles, delivering previously unknown darkness to many residents. Some were alarmed by a silvery light in the black sky. Until then, apparently, the only Milky Way they had ever seen was a candy bar. But perhaps they got some good shut-eye that night.

It wasn’t always this way, Randall writes. People evolved to sleep long hours in a world that got very dark and stayed that way, every night. But modern conditions and lifestyles have left many people short on sleep. Ambient light — which sabotages release of sleep-inducing melatonin — is just one of the many risk factors that Randall investigates in making the case for getting more sleep.

“Without deep sleep, our brain morphs from being our greatest evolutionary asset to our greatest weakness,” Randall writes. In the Gulf War, troops chronically short on rest unwittingly killed their allies. Since then scientists have designed wristwatch-sized sleep monitors that gauge a soldier’s fatigue level. The devices could be standard gear by 2020. “Friendly fire may become a thing of the past,” he says.

Progress elsewhere is slower. The siesta is under attack, for example, even as research finds that naps aid the ability to recognize patterns, recall lists and handle disturbing images.

Dreamland also explores dreaming, of course, and covers apnea, sullen teenagers, sleepwalking, sleep talking, post-sleep grogginess and parasomnia, when half-asleep people perform tasks they can’t remember later. Randall is thorough. If you’ve got a sleep problem, it’s probably in here — even if it’s just plain old insomnia. But, alas, this book won’t put you to sleep.

W.W. Norton & Co., 2012, 290 p., $25.95