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We Don't Sleep Like We Used To
41 million Americans sleep fewer than six hours each night. But it wasn't always this way.
This post originally appeared in RealClearScience's Newton blog. You can read the original here.
Ah, sleep: life's natural, blessed repose from the ardors of arousal. As a physiological necessity, we desire and crave it. Yet for so many Americans, sleep's caressing graces are unattainable. Modern society demands a strict schedule; rest is penciled in as an afterthought. In fact, the CDC reports that approximately 41 million Americans sleep fewer than six hours each night.
But it wasn't always this way. Anthropologists like Matthew Wolf-Meyer and historians like Roger Ekirch are painting a new picture of what sleep was like in our pre-industrial past. Back then, they insist, sleep was regulated not by grueling work schedules, but by the all-encompassing, dark blanket of night.
Chief among Ekirch and Wolf-Meyer's findings, discerned from meticulous searches through court records, letters, diaries, scientific tracts, and popular maxims, was that a sleep pattern known as segmented sleep was widely present in the United Kingdom and United States prior to the 20th century. Before artificial light was bent to our will, most people would retire shortly after dusk, sleep for four or five hours, awaken for an hour or two, then drift back to sleep again until sunrise. Our sleep patterns have only shifted to the current 8-hour consolidated pattern in the decades since electric light became readily available.
"[Humans] are the only consolidated sleepers on the planet," Wolf-Meyer told me in an email, "which leads some people to believe that early human sleep wasn't what it currently is." In his book, The Slumbering Masses, Wolf-Meyer argues that the current norm of consolidating sleep into one uninterrupted block is a social construct, primarily influenced by industrial capitalism.
He may very well be right. Sleep researcher Jessa Gamble has engaged in studies where subjects are (voluntarily) taken down into a bunker deep underground, far away from the cycling sway of light and dark. From observing the sunlight-deprived subjects, the researchers try to zero in on the inner workings of our ingrained clocks. They've found that we're inclined to sleep in many shorter spurts instead of in fewer, longer bouts.
In other studies, sleep researchers deprived subjects of the use of any artificial light. Under these circumstances, amazing changes occur, and sleep cycles emerge that are remarkably similar to those reported by Ekirch and Wolf-Meyer. At TEDGlobal 2010, Gamble said:
...when people are living without any sort of artificial light at all, they sleep twice every night. They go to bed around 8:00 p.m. until midnight and then again, they sleep from about 2:00 a.m. until sunrise. And in-between, they have a couple of hours of sort of meditative quiet in bed. And during this time, there's a surge of prolactin, the likes of which a modern day [person] never sees. The people in these studies report feeling so awake during the daytime, that they realize they're experiencing true wakefulness for the first time in their lives.
Sounds blissful, doesn't it?
Incidentally, prolactin is a peptide-hormone known to be responsible for providing sexual gratification in the wake of orgasm. So it's no wonder that 19th-century couples were widely thought to make use of their middle-of-the-night wakefulness for sex. That wasn't all they did, of course. Individuals also did chores, took care of infants, wrote, read, ate, and quietly contemplated life. The dead of night was a relaxing, yet lively time.
If you're feeling a tad wistful for the good ol' days of segmented sleep, you're probably not alone. Sadly, however, the schedule of America seems to be set. We work. We go home. We sleep. And throughout it all, we yawn.
Maybe, over many years, the hand of selection will subtly and gradually maneuver Americans to adapt to our chosen, apparently unnatural, consolidated mode of sleep. But for now, we're still stuck with being tired.
Scientists used CT scanning and 3D-printing technology to re-create the voice of Nesyamun, an ancient Egyptian priest.
- Scientists printed a 3D replica of the vocal tract of Nesyamun, an Egyptian priest whose mummified corpse has been on display in the UK for two centuries.
- With the help of an electronic device, the reproduced voice is able to "speak" a vowel noise.
- The team behind the "Voices of the Past" project suggest reproducing ancient voices could make museum experiences more dynamic.
Howard et al.<p style="margin-left: 20px;">"While this approach has wide implications for heritage management/museum display, its relevance conforms exactly to the ancient Egyptians' fundamental belief that 'to speak the name of the dead is to make them live again'," they wrote in a <a href="https://www.nature.com/articles/s41598-019-56316-y#Fig3" target="_blank">paper</a> published in Nature Scientific Reports. "Given Nesyamun's stated desire to have his voice heard in the afterlife in order to live forever, the fulfilment of his beliefs through the synthesis of his vocal function allows us to make direct contact with ancient Egypt by listening to a sound from a vocal tract that has not been heard for over 3000 years, preserved through mummification and now restored through this new technique."</p>
Connecting modern people with history<p>It's not the first time scientists have "re-created" an ancient human's voice. In 2016, for example, Italian researchers used software to <a href="https://www.smithsonianmag.com/smart-news/hear-recreated-voice-otzi-iceman-180960570/" target="_blank">reconstruct the voice of Ötzi,</a> an iceman who was discovered in 1991 and is thought to have died more than 5,000 years ago. But the "Voices of the Past" project is different, the researchers note, because Nesyamun's mummified corpse is especially well preserved.</p><p style="margin-left: 20px;">"It was particularly suited, given its age and preservation [of its soft tissues], which is unusual," Howard told <em><a href="https://www.livescience.com/amp/ancient-egypt-mummy-voice-reconstructed.html" target="_blank">Live Science</a>.</em></p><p>As to whether Nesyamun's reconstructed voice will ever be able to speak complete sentences, Howard told <em><a href="https://abcnews.go.com/Weird/wireStory/ancient-voice-scientists-recreate-sound-egyptian-mummy-68482015" target="_blank">The Associated Press</a>, </em>that it's "something that is being worked on, so it will be possible one day."</p><p>John Schofield, an archaeologist at the University of York, said that reproducing voices from history can make museum experiences "more multidimensional."</p><p style="margin-left: 20px;">"There is nothing more personal than someone's voice," he told <em>The Associated Press.</em> "So we think that hearing a voice from so long ago will be an unforgettable experience, making heritage places like Karnak, Nesyamun's temple, come alive."</p>
Inequality in wealth, gender, and race grew to unprecedented levels across the world, according to OxFam report.
- A new report by global poverty nonprofit OxFam finds inequality has increased in every country in the world.
- The alarming trend is made worse by the coronavirus pandemic, which strained most systems and governments.
- The gap in wealth, race and gender treatment will increase until governments step in with changes.
People wait in line to receive food at a food bank on April 28, 2020 in Brooklyn.
Photo by Spencer Platt/Getty Images
Credit: Oxfam International
A supernova exploded near Earth about 2.5 million years ago, possibly causing an extinction event.
- Researchers from the University of Munich find evidence of a supernova near Earth.
- A star exploded close to our planet about 2.5 million years ago.
- The scientists deduced this by finding unusual concentrations of isotopes, created by a supernova.
This Manganese crust started to form about 20 million years ago. Growing layer by layer, it resulted in minerals precipitated out of seawater. The presence of elevated concentrations of 60 Fe and 56 Mn in layers from 2.5 million years ago hints at a nearby supernova explosion around that time.
Credit: Dominik Koll/ TUM