Indholdsfortegnelse for September/October 2017 i Popular Science

YOU PROBABLY WON’T remember this page tomorrow. Don’t worry; I’m not offended. See, these 313 words will take you less than two minutes to read. If you live as long as an average American—78.8 years—my carefully crafted editor’s letter (which took me forever to write) will comprise just 1/29796163 of your life. Or, rounding to the nearest sensible number, zero percent of your dance through this mortal coil. But what if you were a mayfly? Stay with me—I am sober and I have a point, I promise. Forget that mayflies don’t so much think as obey instincts hot-stamped into their DNA, and ignore their lack of literacy. If you were a bookish mayfly—specifically a female of the species Dolania americana— these 83 seconds would represent almost a third of your…

IN THE WILD, TIMING IS EVERYTHING: MILLIONS OF YEARS OF EVOLUTION have made species dependent on seasonal cues. In parts of North America, fall’s cooler weather signals some birds to fly south and avoid Jack Frost’s chill; meanwhile, shifts in both temperature and sunlight tell maple trees to shed their leaves. As Earth warms, some creatures are rapidly recalibrating their clocks. But others, such as caribou in Greenland, have stuck to the same old timetable. For them, the results are catastrophic. Arctic caribou herds arrive at their far-north calving grounds in early June, when grasses and sedges would begin to sprout, providing tender, nutritious meals. Caribou, whose internal clocks rely on seasonal changes in light rather than temperature, still arrive at the same time, but global warming has pushed the…

THE LURE OF TREASURE HUNTING IS NOT THAT OF striking proverbial gold (although some still do search for it), but that you never know what historical holdovers the ground will produce. At the right local spot—an old battlefield or remote beach—these tools will allow you to burrow back in time. 1 Search the area First, you need a metal detector. The Teknetics Patriot can spot booty up to a foot underground, and its display will estimate the object’s depth and material. Audible beeps let you know when metal distorts the electromagnetic field generated by the 11-inch head. $449 2 Dig a tidy hole A hand trowel is great for small digs, but if you need to bust through roots or tough dirt, the serrated edges of the 3-foot-long Ground Hawg…

A SINGLE IMAGE CAN CAPTURE a discreet moment, but stringing dozens or hundreds together into a time-lapse can tell an hourslong story in one spectacular sequence. Start with something simple, like tracing a flower’s bloom over the course of a morning, and, with a little practice, you’ll be able to catch more complex and captivating motion, such as the stars wheeling across the night sky. Here’s what you need to fast-forward time like a pro. 1 Camera The 24.2-megapixel sensor on Nikon’s D5600 DSLR is large enough to capture spectacular night skies that won’t be overwhelmed by ugly pixel noise, and the included zoom lens is ideal for covering landscapes. $800 2 Control The Pulse Camera Remote sits atop your camera and communicates via Bluetooth with a phone app. Use…

THE BEST WAY TO MEASURE SLEEP QUALITY I S IN A LAB, with a dozen or so sensors stuck to your noggin and torso. The 6-inch-tall SleepScore Max tracker ($150) can’t replace a trip to the clinic, but it can give you data about your slumber without even touching you. Plus, it monitors conditions like light, sound, and temperature to perfect your bedroom setup. HOW IT WORKS 1 Throughout the night a small radio emitter sends low-power, high-frequency waves toward your bed 16 times per second. 2Those waves bounce off your upper body, and then return to a built-in sensor, allowing the device to judge your movement and respiration rate. 3 At 30-second intervals, an algorithm determines what sleep stage you’re in (light, deep, or REM), and then transmits the…

I study the intersections between death, dying, and the deceased. What does it mean to be dying, to be dead? The answer has changed a lot throughout history. It’s not hard to figure out how I got here: My dad was a funeral director. I grew up around death. In the early 2000s, he called and asked if I’d help him exhume a grave that was about 30 years old. Unfortunately, the concrete around the casket had cracked, and the whole thing was full of water. It was a big, brown soupy mess. I got into a haz - mat suit and climbed down with a bucket and a rope. I filled up the bucket, scoop by scoop, and my dad hauled it up when it was full. That experience…

In 2010, I was on my first research trip to visit Antarctica’s Skaar Ridge, a 2-mile-long stretch of rock and fossils near the side of a mountain. It can be accessed only via helicopter, so it doesn’t see much foot traffic. The last research team to visit did so back in 1990, and they had left behind one unfortunate casualty: my colleague Professor N. Rubén Cúneo’s hammer. We joked about rescuing our fellow scientist’s old tool, but the odds of finding it were incredibly slim. A hunk of metal and wood could certainly survive a couple of decades in that barren, frozen landscape, but Skaar Ridge is a big place, and wind constantly blows the snow around in Antarctica. There’s a reason it got lost in the first place. You…

EVERYONE HATES AWKWARD PAUSES, AND YOUR brain is no exception. The mind’s eye will attempt to fill in dead spaces—though it’s not always very accurate. Try this: Have a friend give a few taps to your forearm, first near the wrist and then the elbow. Your noggin will confidently assert that something scurried up your arm. The prank even works when the middle of the forearm is numb. Neuroscientists call this trickery the cutaneous rabbit illusion. At its carrot-y roots, the rascal arises from the inaccurate map your brain has of your arm. On your forearm, sensory neurons can separate stimuli that are 1 centimeter apart. (By comparison, your fingertip has sensitivity resolution of 1 millimeter.) The arm’s imprecise measures aren’t a problem if you’re looking at it, but if…

A FASTEST TORTOISE: 0.0017 MILES B USAIN BOLT: 0.0649 MILES C BROWN HARE: 0.132 MILES D CHEETAH: 0.169 MILES E TOYOTA COROLLA: 0.319 MILES F NERVE IMPULSE: 0.745 MILES G SOUND: 2.11 MILES H THE CONCORDE: 3.75 MILES I THE MOON: 6.35 MILES J LIGHT: 1,862,824 MILES THE CONCEPT OF A MINUTE IS KIND OF MEANINGLESS. We can’t even be sure any two organisms experience a minute as the same length of time. Animals with slow metabolisms, like tortoises, perceive it as oozing along, while hares see it whizzing past. In the chaos of relativity, sometimes it’s nice just to have fun. So here’s how far some animals and objects would get in 10 seconds.…

STEVE HANKE IS AGITATED. AN INFLUENTIAL ECONOMIST given to sonorous talks on troubled currencies, he sits in a book-jammed office, jabbing his finger at an offending email printout. It’s from a factotum at Johns Hopkins University, where Hanke is a professor of Applied Economics. The email informs the faculty that, due to the ever-shifting date of Labor Day, fall classes will begin on a Thursday (but on a Monday schedule) and skip a Friday. “Every year,” says Hanke, “I have to completely revise my schedule.” Such jiggering is a waste of his time. Multiply his frustration by an entire school, add the time suck at thousands of other places making similar changes—sports leagues, government agencies, your company—and you get chaos! Trillions of wasted work hours! “Imagine the meetings!” says Hanke,…

APPLY ENOUGH HEAT TO WATER AND IT WILL EVENTUALLY BOIL, BUT TRY TO convince your brain of that while you impatiently loiter in your kitchen, listening for your old kettle to whistle. Your noggin is a timekeeper, and the more you pay attention to each passing second, the longer your suffering seems to last. It would take just 10.16 minutes to boil a gallon of water on an impossible stove with ideal heat transfer, and the wait would still feel like torture. The good news: These vessels were built for maximum efficiency and temperature control, to minimize the pain of waiting for those little bubbles to start rising. At Home You can boil any liquid you want in the Fellow Raven Stovetop Kettle + Tea Steeper, but its specialty…

IT TAKES JUST A LITTLE MORE THAN TWO SECONDS FOR THE $85,000 Dodge Challenger SRT Demon to reach 60 miles per hour. That makes it the fastest production car on the planet when it comes to pure, straightline drag-race-style acceleration. The Demon needs excessive amounts of raw power to pull off speedy feats, like clock a quarter-mile in just 9.65 seconds, or hit a top speed of 168. Here’s how this chunky mass of American muscle manages to rival the kind of vehicle that travels with a pit crew. 840 HORSEPOWER In drag mode, a transmission-locking system allows the driver to rev the Demon’s supercharged V-8 up to 2,350 rpm without the car creeping forward, making for greater torque at go time. 770 FOOT-POUNDS The car generates enough torque to…

ELISA FELICITAS ARIAS Director, Time Department , International Bureau of Weights and Measures “I HAVE A VERY BAD relationship to time” is not a confession you expect from the person in charge of the world’s official time standard. Yet Elisa Felicitas Arias admits to a certain laissez-faire approach to personal punctuality. “I’ve never missed a flight or anything like that,” she clarifies, “but no two clocks in my house give the same time.” This laid-back way with hours and minutes doesn’t carry over into her day job. As director of the Time Department at the International Bureau of Weights and Measures just outside Paris, Arias formulates Coordinated Universal Time (UTC), the 24-hour standard to which governments, militaries, and scientific bodies synchronize every clock-bearing device—from hyperaccurate global-positioning satellites to weather…

As a neuroanatomist at Harvard, I studied how our brain creates our perception of reality. And then one morning, I woke up with a sharp pain directly behind my left eye. In the course of four hours, I lost the ability to walk, talk, read, write, or recall any of my life. I was experiencing a major hemorrhage, bleeding in the left half of my brain, which rendered me an infant in a woman’s body. The perception of time is, of course, controlled by cells inside our brains. Cells in the left hemisphere allow us to think linearly, to recognize that things happen in a certain order. My stroke completely shut down those cells, leaving me dependent on my right hemisphere, which doesn’t register anything beyond the present. I had…

NOT EVERY SECOND IS MADE THE SAME—AT least as far as our noggins are concerned. Quickly glance at an analog clock. You might find that the second hand seems stuck at first. But if the precise machinery ensures every second is the same, why the pause? Amelia Hunt, a neuroscientist with the University of Aberdeen in Scotland, says the standstill (nicknamed the stopped-clock illusion) occurs because our brains anticipate what we will see before we actually view it. When we move our eyes, everything shifts position on the retina. If we couldn’t sense those adjustments coming, we’d be incredibly disoriented. So our brains figured a way to cope: As we navigate the world, our visual cortex creates and updates an interactive map of what’s around us. The brain uses it…

A GUY WALKS INTO A BAR. THE ROBOT BARTENDER ASKS, “What’ll it be?” But when does the bot greet him? As soon as the man walks in? After he’s browsed the taps? A machine with no sense of social graces would not know the answer. That is, unless you taught it the delicate art of timing. According to Oregon State robotics professor Heather Knight, robots must understand how humans perceive time in order to build relationships with us. To teach them, Knight helps robots read our cues. For instance, a drinker in a hurry will take a direct, not a meandering, route to the barstool. But unpacking human body language is only part of what a would-be bionic barkeep might have to process. A customer enters DRINK SERVER We imagined…

IMAGINE A ROAD TRIP THAT lasts six months—no pit stops, black night the whole way. That’s how long it would take you, and how monotonous it would be, to fly to Mars. To avoid the boredom (and its cousins depression and anxiety), you could spend part of your trip in artificial hibernation, or torpor, as it’s medically known. NASA is funding research into this method for future planet hoppers, and not just to reduce the games of I Spy. Because metabolism slows during slumber, you would require less food and water, reducing a mission’s cargo weight, fuel needs, and price tag. Also, you wouldn’t want to kill your crew mates. Here’s how you might go nightynight and save your sanity on your 34-million-mile flight. FUTURE PREVIEW [ STEP 1 ]…

VIDEO RUNNING AT THE SPEED OF MOLASSES REVEALS hidden movements our feeble peepers can’t typically see. While most footage is filmed at 30 or so frames per second (fps), the ultrafast cameras below can capture hundreds or thousands. When played back at a normal rate, the movies stretch out time, creating cinematic magic. SLOW GoPro Hero5 Black Like many smartphones, this action camera can record footage at 240 fps, or eight times slower than real life. Unlike your smartphone, however, it can plunge up to 33 feet underwater and survive sky-high drops, so it can go where the action is. Try ?ilming the mesmerizing-but-gross undulations of a dog’s tongue as it drinks from a bowl of water. $399 SLOWER Sony RX100 Mark V Moments shot at this camera’s 1,000 fps…

TO A CHILD, ONE YEAR CAN FEEL LIKE AN ETERNITY. BUT TO THAT kiddo’s grandparents, it passes in a flash. The same is true for the oldest flora and fauna on the planet. As things age, each trip around the sun becomes an ever-shrinking percentage of a vast lifetime. Take 38-year-old Creme Puff (RIP), the oldest known house cat: 365 days was only 2.6 percent of her yarn-chasing journey through existence. That might not seem like a lot to, say, the Grand Canyon (if it could think, that is), but, as this graph shows, it’s all relative. MAXIMUM KNOWN LIFE SPAN AGE OF THE OLDEST HUMAN 122.5 JEANNE CALMENT (1875-1997) She rubbed olive oil into her skin, ate 2 pounds of chocolate per week, avoided stress—and smoked. 300 SECONDS MOST…

During Antarctica’s warm(er) season, the sun shines constantly. Without darkness to divide night from day, researchers find ways to cope. After 21 field seasons, here are ecologist Ross Virginia’s must-haves. 1 Sunglasses I’m not trying to make a fashion statement. It’s constantly bright and it’s wicked dry, so I protect my eyes with dark glasses that have side coverage and 100 percent UV protection. 2 Music When you finally stop working after a long day in the field, it can be hard to sleep. Music helps me make that transition. I’ve rigged an Altoids box to hold a small speaker that connects to an iPod. 3 Night Shade To block out the midnight sun, I use a neck warmer as an eye mask. During the day, I can use it…

trip meter UNLIKE ACTUAL SNAKES, YOU DON’T need to keep a keen eye on the spiraling ones above. In fact, for your sanity, it’s probably best to ignore them: These playful circles stay still when you stare them down one at a time, but spin frustratingly when spied all together. Akiyoshi Kitaoka, a psychologist at Ritsumeikan University in Kyoto, Japan, made this take on peripheral drift illusions—which make the brain miscast patterns as motion. Neuroscientists think the shapes mess with the way our brain adapts to disparities in color contrast. When we glance at this image, the blacks and whites cause a bunch of neurons to fire at once. At the same time, the paler blues and yellows trigger a slower, longer-lasting response. Motion-detecting neurons in the visual cortex mistake…