By DAVID K. RANDALL

SOMETIME in the dark stretch of the night it happens. Perhaps it’s the chime of an incoming text message. Or your iPhone screen lights up to alert you to a new e-mail. Or you find yourself staring at the ceiling, replaying the day in your head. Next thing you know, you’re out of bed and engaged with the world, once again ignoring the often quoted fact that eight straight hours of sleep is essential.

Sound familiar? You’re not alone. Thanks in part to technology and its constant pinging and chiming, roughly 41 million people in the United States — nearly a third of all working adults — get six hours or fewer of sleep a night, according to a recent report from the Centers for Disease Control and Prevention. And sleep deprivation is an affliction that crosses economic lines. About 42 percent of workers in the mining industry are sleep-deprived, while about 27 percent of financial or insurance industry workers share the same complaint.

Typically, mention of our ever increasing sleeplessness is followed by calls for earlier bedtimes and a longer night’s sleep. But this directive may be part of the problem. Rather than helping us to get more rest, the tyranny of the eight-hour block reinforces a narrow conception of sleep and how we should approach it. Some of the time we spend tossing and turning may even result from misconceptions about sleep and our bodily needs: in fact neither our bodies nor our brains are built for the roughly one-third of our lives that we spend in bed.

The idea that we should sleep in eight-hour chunks is relatively recent. The world’s population sleeps in various and surprising ways. Millions of Chinese workers continue to put their heads on their desks for a nap of an hour or so after lunch, for example, and daytime napping is common from India to Spain.

One of the first signs that the emphasis on a straight eight-hour sleep had outlived its usefulness arose in the early 1990s, thanks to a history professor at Virginia Tech named A. Roger Ekirch, who spent hours investigating the history of the night and began to notice strange references to sleep. A character in the “Canterbury Tales,” for instance, decides to go back to bed after her “firste sleep.” A doctor in England wrote that the time between the “first sleep” and the “second sleep” was the best time for study and reflection. And one 16th-century French physician concluded that laborers were able to conceive more children because they waited until after their “first sleep” to make love. Professor Ekirch soon learned that he wasn’t the only one who was on to the historical existence of alternate sleep cycles. In a fluke of history, Thomas A. Wehr, a psychiatrist then working at the National Institute of Mental Health in Bethesda, Md., was conducting an experiment in which subjects were deprived of artificial light. Without the illumination and distraction from light bulbs, televisions or computers, the subjects slept through the night, at least at first. But, after a while, Dr. Wehr noticed that subjects began to wake up a little after midnight, lie awake for a couple of hours, and then drift back to sleep again, in the same pattern of segmented sleep that Professor Ekirch saw referenced in historical records and early works of literature.

It seemed that, given a chance to be free of modern life, the body would naturally settle into a split sleep schedule. Subjects grew to like experiencing nighttime in a new way. Once they broke their conception of what form sleep should come in, they looked forward to the time in the middle of the night as a chance for deep thinking of all kinds, whether in the form of self-reflection, getting a jump on the next day or amorous activity. Most of us, however, do not treat middle-of-the-night awakenings as a sign of a normal, functioning brain.

Doctors who peddle sleep aid products and call for more sleep may unintentionally reinforce the idea that there is something wrong or off-kilter about interrupted sleep cycles. Sleep anxiety is a common result: we know we should be getting a good night’s rest but imagine we are doing something wrong if we awaken in the middle of the night. Related worries turn many of us into insomniacs and incite many to reach for sleeping pills or sleep aids, which reinforces a cycle that the Harvard psychologist Daniel M. Wegner has called “the ironic processes of mental control.”

As we lie in our beds thinking about the sleep we’re not getting, we diminish the chances of enjoying a peaceful night’s rest.

This, despite the fact that a number of recent studies suggest that any deep sleep — whether in an eight-hour block or a 30-minute nap — primes our brains to function at a higher level, letting us come up with better ideas, find solutions to puzzles more quickly, identify patterns faster and recall information more accurately. In a NASA-financed study, for example, a team of researchers led by David F. Dinges, a professor at the University of Pennsylvania, found that letting subjects nap for as little as 24 minutes improved their cognitive performance.

In another study conducted by Simon Durrant, a professor at the University of Lincoln, in England, the amount of time a subject spent in deep sleep during a nap predicted his or her later performance at recalling a short burst of melodic tones. And researchers at the City University of New York found that short naps helped subjects identify more literal and figurative connections between objects than those who simply stayed awake.

Robert Stickgold, a professor of psychiatry at Harvard Medical School, proposes that sleep — including short naps that include deep sleep — offers our brains the chance to decide what new information to keep and what to toss. That could be one reason our dreams are laden with strange plots and characters, a result of the brain’s trying to find connections between what it’s recently learned and what is stored in our long-term memory. Rapid eye movement sleep — so named because researchers who discovered this sleep stage were astonished to see the fluttering eyelids of sleeping subjects — is the only phase of sleep during which the brain is as active as it is when we are fully conscious, and seems to offer our brains the best chance to come up with new ideas and hone recently acquired skills. When we awaken, our minds are often better able to make connections that were hidden in the jumble of information.

Gradual acceptance of the notion that sequential sleep hours are not essential for high-level job performance has led to increased workplace tolerance for napping and other alternate daily schedules.

Employees at Google, for instance, are offered the chance to nap at work because the company believes it may increase productivity. Thomas Balkin, the head of the department of behavioral biology at the Walter Reed Army Institute of Research, imagines a near future in which military commanders can know how much total sleep an individual soldier has had over a 24-hour time frame thanks to wristwatch-size sleep monitors. After consulting computer models that predict how decision-making abilities decline with fatigue, a soldier could then be ordered to take a nap to prepare for an approaching mission. The cognitive benefit of a nap could last anywhere from one to three hours, depending on what stage of sleep a person reaches before awakening.

Most of us are not fortunate enough to work in office environments that permit, much less smile upon, on-the-job napping. But there are increasing suggestions that greater tolerance for altered sleep schedules might be in our collective interest. Researchers have observed, for example, that long-haul pilots who sleep during flights perform better when maneuvering aircraft through the critical stages of descent and landing.

Several Major League Baseball teams have adapted to the demands of a long season by changing their sleep patterns. Fernando Montes, the former strength and conditioning coach for the Texas Rangers, counseled his players to fall asleep with the curtains in their hotel rooms open so that they would naturally wake up at sunrise no matter what time zone they were in — even if it meant cutting into an eight-hour sleeping block. Once they arrived at the ballpark, Montes would set up a quiet area where they could sleep before the game. Players said that, thanks to this schedule, they felt great both physically and mentally over the long haul.

Strategic napping in the Rangers style could benefit us all. No one argues that sleep is not essential. But freeing ourselves from needlessly rigid and quite possibly outdated ideas about what constitutes a good night’s sleep might help put many of us to rest, in a healthy and productive, if not eight-hour long, block.

By: Adam Frank
NY Times, July 24, 2012

SOMETIME this year Voyager 1, a probe sent from Earth 35 years ago, will cross a threshold no human-fashioned object has reached before. Passing through a sun-driven shock wave at the edge of the solar system, it will reach the icy dominions of interstellar space. Voyager is one of the fastest vessels we’ve ever blown out of Earth’s gravity well. Still, after three and a half decades of hyper-velocity spaceflight, it will take another 700 centuries for the craft to cross the distance to the nearest star.

Short of a scientific miracle of the kind that has never occurred, our future history for millenniums will be played out on Earth and in the “near space” environment of the other seven planets, their moons and the asteroids in between. For all our flights of imagination, we have yet to absorb this reality. Like it or not, we are probably trapped in our solar system for a long, long time. We had better start coming to terms with what that means for the human future.

Of course, we know this, on some level. But in a culture saturated with inbred notions of “progress” and an obsession with worlds seemingly just beyond our grasp, there is an expectation that sooner rather than later, we will be building an interstellar culture. In a kind of cosmic version of Manifest Destiny we assume that, unless something terrible happens, our science will be taking us to the stars sometime in the next few hundred years. Simply say “warp drive” to just about anyone and see if they know what you mean.

From “Star Trek” to “Star Wars,” from warp drive to hyperdrive — the idea of rapid interstellar space travel is such a deep meme for cultural visions of space and our future that Hollywood films don’t even have to waste time introducing them to the audience. You pull a lever and zap — you are in a new star system. How many people would be surprised to know that warp drive isn’t even a coherent concept, let alone a near-future technology?

The truth is we propel ourselves into space using much the same physics as the Chinese played with when they discovered what we came to call gunpowder more than 1,400 years ago. Blowing stuff up under us is just about the only way we know how to travel through the void.

But for the distances between the stars, that method simply won’t cut it. Even if we could find a way to increase the speed of our spacecraft a hundredfold — about the same ratio of speeds between a horse-drawn cart and a 747 jet plane — they would still take almost a thousand years to reach nearby stars, and as long to return. And while exciting theoretical research is under way into pilotless probes to the stars, the real possibility of large-scale human interstellar culture is considerably less thrilling.

Think about it. No salvation from population pressure on the shores of alien worlds. No release from the threats of biosphere degradation in the promise of new biospheres. No escape from our own destructive tendencies by spreading out among the stars like seedpods in the wind. For as many epochs in the future as there are epochs of human history in the past, we may simply have to make do, get by with what we have and, in the end, learn to get along.

I was just 15 when Voyager 1 left on its long journey. At that age I already knew I wanted nothing more than to be an astronomer. I was also sure that humanity’s future, even on the time scale of centuries, would be played out in the theater of the stars. Voyager’s departure on its interstellar mission convinced me we were well on our way toward that grand future where anything would be possible.

Today I am still in awe of that tiny box of electronics as it sails to the edge of the solar wind. I still believe it represents the best of human genius, ambition and hope. It is through these qualities that, I believe, we have taken the full measure of the stars.

But what we’ve learned in doing so brings me, as an adult and as an astrophysicist, to the hardest and most inconvenient truth of all. While our children’s children’s great-grandchildren will live with ever more powerful technology, they will also live ever more intimately with ever more billions of others in this, our corner of the cosmos. Looking back and forward, my bets are now on that same human genius, ambition and hope to rise to the occasion. We will have no other choice. There will be nowhere else to go for a very long time. (via)

By Yasmin Anwar

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