Why Is It So Hard to Sleep in a New Place?

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iStock

Maybe you’re away on a business trip and you’ve got a big presentation in the morning. Maybe it’s your first night in a new home after a long day hauling boxes. Whatever the circumstances, you could really use a good night’s rest—but, given that you're sleeping in a new place, that may be easier said than done. Now, a team of scientists at Brown University say they’ve found a cause for this first-night effect: constant, animal-like vigilance. They published their findings in the journal Current Biology.

Sleep is something of a puzzle for scientists. Most animals do it, but it’s not entirely clear why it’s necessary. In survival terms, it’s pretty inconvenient for an animal to be off its guard for several hours every day. But rather than evolving to live without rest, some animals have developed the ability to literally sleep with one eye open. Bottlenose dolphins, southern sea lions, domesticated chickens, and beluga whales are among species that practice unihemispheric slow-wave sleep (USWS), in which just one half of the brain sleeps at a time.

You can see this yourself in a line of snoozing ducks: the duck at the end of the line will have its outward-facing eye open. That eye is linked to the brain hemisphere that’s still awake. That way, even in sleep, the sight of a predator could trigger alarms in the brain, cueing the duck to take action.

This may look like an angry pirate, but it’s actually a young house sparrow in USWS. Image credit: Hussain Kaouri via Wikimedia Commons // CC BY-SA 4.0

As you can imagine, this vigilant half-sleep is a real asset in dangerous and unpredictable environments. Unfortunately, your brain might count hotel rooms and new apartments as dangerous. That’s right: Scientists have found USWS in people. Or, rather, they’ve found what amounts to USWS Lite.

Sleep researchers are well aware of the first-night effect (FNE), and frequently throw out the results from a sleep study subject’s first night in the lab. Rather than working around the FNE, a team of researchers decided to identify its cause. They recruited 35 healthy volunteers and brought them into a sleep lab for two nights of sleep with a one-week break in between. The volunteers were hooked up to machines that measured their heart rates, blood oxygen levels, breathing, eye and leg movements, as well as activity in both sides of the brain.

The scientists focused on slow-wave activity (SWA), a type of brain behavior that can indicate how deeply someone is sleeping. They looked at SWA in four different brain pathways in both sleep sessions, tracking how sleep depth was affected by disturbances in the room.

They weren’t looking for differences between the brain hemispheres, but they found them. On the first night of sleep, subjects consistently showed more wakefulness in the left half of their brains. The left hemisphere was also more sensitive to strange (and thus potentially threatening) sounds. One week later, when the subjects returned to the sleep lab, there was more symmetry in the subjects’ brain activity, suggesting they had become accustomed to the now familiar environment. Their SWA showed equal levels of wakefulness, or lack thereof, in both brain hemispheres.

While the study results suggest we are participating in USWS, co-author Yuka Sasaki says in a press statement that "our brains may have a miniature system of what whales and dolphins have."

Sasaki noted that frequent travelers may subconsciously train their brains to bypass the FNE. Our brains are “very flexible,” she said. “Thus, people who often are in new places may not necessarily have poor sleep on a regular basis."

The team’s future experiments will include trying to shut off the FNE so people can get a better (first) night’s sleep. 

Why Are Sloths So Slow?

Sloths have little problem holding still for nature photographers.
Sloths have little problem holding still for nature photographers.
Geoview/iStock via Getty Images

When it comes to physical activity, few animals have as maligned a reputation as the sloth. The six sloth species, which call Brazil and Panama home, move with no urgency, having seemingly adapted to an existence that allows for a life lived in slow motion. But what makes sloths so sedate? And what horrible, poop-related price must they pay in order to maintain life in the slow lane?

According to HowStuffWorks, the sloth’s limited movements are primarily the result of their diet. Residing mainly in the canopy vines of Central and South American forests, sloths dine out on leaves, fruits, and buds. With virtually no fat or protein, sloths conserve energy by taking a leisurely approach to life. On average, a sloth will climb or travel roughly 125 feet per day. On land, it takes them roughly one minute to move just one foot.

A sloth’s digestive system matches their locomotion. After munching leaves using their lips—they have no incisors—it can take up to a month for their meals to be fully digested. And a sloth's metabolic rate is 40 to 45 percent slower than most mammals' to help compensate for their low caloric intake. With so little fuel to burn, a sloth makes the most of it.

Deliberate movement shouldn’t be confused for weakness, however. Sloths can hang from branches for hours, showing off some impressive stamina. And because they spend most of their time high up in trees, they have no need for rapid movement to evade predators.

There is, however, one major downside to the sloth's leisurely lifestyle. Owing to their meager diet, they typically only have to poop once per week. Like going in a public bathroom, this can be a stressful event, as it means going to the ground and risking detection by predators—which puts their lives on the line. Worse, that slow bowel motility means they’re trying to push out nearly one-third of their body weight in feces at a time. It's something to consider the next time you feel envious of their chill lifestyle.

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Are Any of the Scientific Instruments Left on the Moon By the Apollo Astronauts Still Functional?

Apollo 11 astronaut Neil Armstrong left the first footprint on the Moon on July 20, 1969.
Apollo 11 astronaut Neil Armstrong left the first footprint on the Moon on July 20, 1969.
Heritage Space/Heritage Images/Getty Images

C Stuart Hardwick:

The retroreflectors left as part of the Apollo Lunar Ranging Experiment are still fully functional, though their reflective efficiency has diminished over the years.

This deterioration is actually now delivering valuable data. The deterioration has multiple causes including micrometeorite impacts and dust deposition on the reflector surface, and chemical degradation of the mirror surface on the underside—among other things.

As technology has advanced, ground station sensitivity has been repeatedly upgraded faster than the reflectors have deteriorated. As a result, measurements have gotten better, not worse, and measurements of the degradation itself have, among other things, lent support to the idea that static electric charge gives the moon an ephemeral periodic near-surface pseudo-atmosphere of electrically levitating dust.

No other Apollo experiments on the moon remain functional. All the missions except the first included experiment packages powered by radiothermoelectric generators (RTGs), which operated until they were ordered to shut down on September 30, 1977. This was done to save money, but also because by then the RTGs could no longer power the transmitters or any instruments, and the control room used to maintain contact was needed for other purposes.

Because of fears that some problem might force Apollo 11 to abort back to orbit soon after landing, Apollo 11 deployed a simplified experiment package including a solar-powered seismometer which failed after 21 days.

This post originally appeared on Quora. Click here to view.

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