The advent of electricity changed the way we sleep.
"Get your eight hours." It’s a command so familiar it feels timeless—an unquestioned truth that humans naturally need a full night’s sleep. But a closer look at historical sleep patterns challenges the idea that even our biological needs exist outside the influence of time and culture.
The Social Transformation of Nighttime
For much of recorded history, humans have actually slept eight hours, but in two distinct phases of approximately four hours each. As scholar Roger Ekirch uncovered through historical study of literature, art and diaries, people would once head to bed when it got dark, sleep for four hours, wake for a while, and then slide into a “second sleep” for another four hours. People didn’t just toss and turn along in between their two sleep sessions: they would contemplate their dreams, read by candlelight or have sex.
Writers from Livy to Plutarch to Virgil to Homer all referred to this structure, as well as medieval Christian and African tribal cultures. But the “biphasic sleep” pattern, which was governed by the natural timing of nightfall and sunrise, didn’t last in the modern era.
As artificially illuminating the night sky became more affordable, life—and soon sleep habits—changed. Fifty European cities introduced tax-supported street lighting by 1700 and made it safe and socially acceptable to move about publicly after dark, a time of day that had previously been considered the domain solely of prostitutes and other suspicious characters. The assumption that nothing good could go on at night was so widespread that until the arrival of artificial lighting, citizens often freely emptied their “piss-pots” out of windows after dark.
In the United States, Baltimore became the first city to be lit by gas in 1816; a century later, electricity in streets and in growing numbers of homes meant nightfall no longer ensured the inescapable darkness that had dictated beginning one’s first sleep soon after. Going out at night became a fashionable social pastime, pushing bedtime later and bringing the two separate sleep phases closer to the single stretch we know today.
Industrialization and the Single Sleep Cycle
It was industrialization that solidified the single sleep as a social norm. Especially in the cities that increasingly revolved around factory production, a newly formalized workday structured daily life and a fascination with productivity meant that spending hours lolling around in the middle of the night was considered slothful.
School schedules also became increasingly standardized, and as early as the 1820s, parenting books advised promptly weaning children from the two-sleep pattern. By the late 19th century in the United States, school attendance was compulsory, creating yet another cultural pressure to conform to this new sleeping schedule.
Clocks had existed since the ancient world, but when Levi Hutchins of New Hampshire in 1787 fashioned the first mechanical alarm clock specifically to rouse him for work, it marked a new understanding of the relationship between sleep and labor. Half a century later, Frenchman Antonie Redier patented the invention; in 1876, Seth E. Thomas mass-produced a wildly popular American version embraced by a society required to adjust its biological rhythms to the industrial clock. By World War II, the U.S. Office of Price Administration reluctantly lifted a production ban on “emergency” alarm clocks since workers with broken devices were sleeping through factory shifts crucial to the war effort.
Perhaps the most compelling evidence of the general acceptance of this new norm is the anxiety among and about those who failed to abide by it. In medieval Europe, for example, historian Eluned Summers-Bremner found that nocturnal wakefulness was encouraged as a form of vigilance against bedbugs, arsonists or the Devil, who was believed to prey on the oblivious slumberer. But by the late 19th century, insomnia—defined as the inability to sleep restfully through a single sleep cycle—had been categorized as a disorder, signaling the end of the era of the unproblematic segmented sleep.
These days, advice literature continues to idealize the elusive, uninterrupted 8-hour slumber ironically eroded by our 24/7 connectedness. Yet if there is a “natural” sleep cycle to aspire to, science suggests it is closer to the biphasic model.
Who Invented the Alarm Clock?
They have been around as far back as ancient times—but the snooze button didn't arrive until 1956.
As early as the 5th century B.C., the Greek philosopher Plato invented an ingenious water clock that not only accurately measured the passage of time, but also sounded a whistle to wake him for his morning lectures. The Buddhist monk Yixing built the first water-driven mechanical clock around A.D. 700 and Chinese tower clocks may have inspired the first European mechanical clocks, which appeared in the 13th century. The classic tabletop alarm clock with a clattering bell didn’t emerge until the 19th century, introduced by French and American clockmakers. The first snooze button didn’t arrive until 1956.
Why were the first alarm clocks invented?
Monks were some of the first people who cared deeply about accurately tracking the passage of time. For centuries, they relied on water-driven clocks that would ring a bell to mark their daily rituals—for example, when they needed to pause at the eighth hour of daylight for prayer. When the first mechanical clocks arrived in the late 13th-century—they, too, were used in ecclesiastical contexts, to keep prayer, work and meal schedules and, increasingly, in the bell towers of churches. In fact, the word “clock” comes from the Latin clocca, which means “bell.”
Who invented the modern alarm clock?
Mechanical clocks were exclusively for the rich through at least the 17th century. Only churches, royal palaces and the very wealthiest households could afford these intricate, hand-made machines. In addition to telling time, many clocks and even watches in 16th-century Europe had programmable alarms. Queen Elizabeth I reportedly owned a tiny ring-based watch that sounded a “silent alarm,” reminding her of her appointments by gently scratching her finger with a metal prong.
Levi Hutchins, an American clockmaker, built one of the first (relatively) affordable alarm clocks in 1787. Hutchins, who lived in Concord, New Hampshire, engineered his wooden, cabinet-style clock to ring a bell every morning at precisely 4 a.m., his preferred wake-up time. Hutchins didn’t patent his invention, which is just as well, because not everyone wants to get up before dawn.
When did alarm clocks become household fixtures?
Fifty years after Hutchins, a French clockmaker named Antoine Redier is credited with filing the first patent for an alarm clock in 1847, closely followed in 1852 by a U.S. patent for a “Time-Alarm Clock” by J.S. Turner.
It wasn’t long before clockmakers were selling “illumination alarm clocks” that struck a match and lit an oil lamp at the sound of the bell. Think of them as the world’s first “sunrise” alarm clocks.
In 1876, the Seth Thomas Clock Company patented the standard bedside alarm clock, which became mass produced at the turn of the 20th century. The first alarm clock with a snooze button came from General Electric-Telechron, which designed the futuristic 1956 “Snooz-Alarm.” Because of the size and shape of the clock’s alarm gear, the snooze function only worked for nine minutes, not 10. All these years later, that’s still the standard snooze time, even for smartphones.