Indholdsfortegnelse for Fall 2020 i Popular Science

YEARS BEFORE TRUE-CRIME podcasts sent hordes of listeners-​turned-​internet-​sleuths onto message boards, my brother and I spent our weeknights cross-​legged on the living room floor, glued to Unsolved Mysteries. Host Robert Stack narrated real-life tales of cold cases, hauntings, and UFO sightings set against archival images, interviews, and re-​creations of the events. At its peak, nearly 17 million people tuned in. NBC canceled the show in 1997 after a 10-year run. But it keeps coming back; networks have reincarnated the series four times. Despite host changes (the recent Netflix reboot eschews one altogether) and production upgrades, much has remained the same—most importantly a request that viewers call in with any information that might help solve cases. There are a lot of scientific notions, mostly psychological, that explain the true crime genre’s…

YOU DREAM FOR TWO HOURS every night, but for something so common, it’s a remarkably enigmatic process. Only in the past few decades, with the advance of technology like fMRIs that lets us record and visualize activity in the brain, have neuroscientists begun to figure out how and why we experience these reveries. While sleepy interludes seem to rely on many of the same mental processes we use while awake, researchers are still trying to understand the way they work together during slumber. Here’s how we think our brains drive our nocturnal hallucinations. A/Remember Dreams tap memories stored in connections between brain cells, which the hippocampus tracks as they form. At night it directs neurons to replay recollections, facilitating long-​term storage. That could be why reality seeps into our visions—​but…

ASTRONOMERS HAVE SPENT centuries filling in their sketches of our corner of the Milky Way. But these charts, like all maps, are only approximations of reality. Their blind spots likely harbor some unknown entities—bodies too small, too close to the sun, or too far away for us to see. Here are some celestial objects that stargazers have suspected of dodging their telescopes over the years. Vulcan and the Vulcanoids Astronomers once interpreted an oddity in Mercury’s orbit as a sign of a planet hiding in the sun’s rays. Einstein’s theory of gravity explained it away, but the zone could harbor asteroids (“vulcanoids”). They’d be small: NASA’s twin sun-observing STEREO spacecrafts would have spotted any wider than a few miles. Lost Ice Giant In digital reenactments of its early days, the…

IN 2008, KORONIS PHARMAceuticals wrapped up the second phase of trials for a new HIV treatment described as a “mutation booster.” PopSci soon wrote about the intriguing procedure, which would supposedly introduce mistakes into the virus’s DNA and cause it to self-destruct: “In the movies, this technique, known as lethal mutagenesis, would create a supergerm, but in real life it’s spawning a powerful new class of antiviral drugs.” The therapy failed to trigger viral suicide, and experiments ceased. HIV deaths have since fallen sharply thanks to prophylactic medication, safe sex, and drugs that keep the pathogen from replicating, but the virus continues to elude one-shot methods. “It plays a cat-and-mouse game with the immune system,” says Bali Pulendran, a professor of immunology at Stanford. HIV mutates at breakneck speed, throwing…

IN EARLY DECEMBER OF 2013, Emile Ouamouno, a 2-year-old boy in southern Guinea, began vomiting from an unknown illness. A few days later, he died. Then, just around New Year’s, his mother and sister succumbed to similar symptoms. This is the story that their father, Etienne Ouamouno, told disease specialists when they arrived in his village in hazmat suits the following year. Using viral samples collected from dozens of Guineans, a European lab confirmed the cause: Ebola, a highly infectious pathogen picked up from bats that kills close to half of its victims, often via hemorrhaging. But the tests didn’t identify the origins of the outbreak—so doctors headed back into the field to interview those affected about their comings and goings. After three months of fact-finding, the chain of cases…

MYSTERY FLAVORS HAVEmultiplied on store shelves of late. Companies tempt consumers into guessing obscure tastes in special editions of everything from chips to cookies. But at least one cryptic bite’s profile remains under wraps: Laffy Taffy debuted its White Mystery Airhead in 1993, and the monochrome concoction continues to baffle. The candymaker receives heaps of fan theories every day—from tart lemon to smooth vanilla—but no one has gotten it right. Today, only a few dozen people know the secret identity; the rest of us have to settle for simpler certitudes. The tang of citric acid makes White Mystery undeniably fruity, and a mixture of sugar and corn syrup adds ample sweetness. The absence of color, however, is the curveball: It deprives the brain of the visual cues that can help…

AFTER DARK, YOUR BACKYARD COULD transform into a buffet for elusive critters like foxes, owls, and even black bears. Whether your home is near suburban woods or a swampy jungle, a Moultrie XA-6000 camera will capture the evidence in HD. The gadget links with a phone app that’ll let you know when something is afoot. Here’s what’s going on under its weather-resistant shell. 1 Find a good perch To mount the 8-inch-tall device, hang it by its nylon strap some 3 feet off the ground, giving the wide-angle lens an ideal perspective. The AA batteries will provide power 24/7 for around 12 weeks. 2 Wait for evening When an onboard infrared sensor detects motion within 80 feet and a temperature warmer than the air, it activates a night-​vision camera. It…

DOCTORS GAVE CLARK MARTIN A YEAR TO LIVE AFTER TO THEY FOUND HE HAD STAGE 4 KIDNEY CANCER IN 1990. “I’M STILL HERE,” HE SAYS NOW. If the statement doesn’t carry the triumphant tone one might expect of a person who has survived decades longer than medical science predicted, that’s because the years of treatments, and the constant threat of death, dulled and depressed him for a long time. “It was exhausting,” he says, “and it was no way to live.” In 2010, almost 20 years into his battle with cancer, Martin read about a strange research program. Participants wouldn’t take a magic pill that might shrink their tumors in a novel way. No. They’d be getting drug-drugs: Brain scientists wanted to see how hallucinogens that alter thinking patterns and…

Pablo Picasso’s noted portrait of literary icon Gertrude Stein has long mystified art historians. Between the fall of 1905 and the spring of 1906, the author sat for the artist more than 80 times—​an atypically lengthy process for the accomplished painter. Contemporary reports suggest Picasso kept restarting his work. For years chemists and conservators have been trying to unravel the artist’s tedious creative process. In earlier studies, researchers placed the artwork in an X-ray machine, which identifies the presence of heavy elements common in pigments, such as mercury and lead. If Picasso painted over something, it would reveal what’s underneath. But X-rays can only detect dense metals, so the studies unveiled just a handful of edits. In 2019, MET conservator Isabelle Duvernois and I used a newer technology called macro…

1. Riley Black • Megalodon, a 50-foot shark known as the T. rex of the seas, almost certainly ceased to exist around 3 million years ago. But on page 46, writer and amateurpaleontologist Riley Black poses the question: What if this toothy beast is still around? It’s the kind of topic she’s been considering since middle school, when she became obsessed with dinosaurs. In college Black poured that passion into a blog and eventually a career reporting magazine articles and books, the latest of which is Skeleton Keys. She now spends her summers wandering the desert, digging up fossils: “It’s a way to time travel,” she reflects. 2. Tomi Um • It took four years for the career of Brooklyn-​based illustrator Tomi Um to take off, but when it did,…

SPECIAL EDITION The Mysteries of Disease IN 1995, ERIC PEVZNER TOOK A TEMPORARY GIG AT HISalma mater, Michigan State University, while he applied to med school. But this project—investigating how a sense of community influences wellness—intrigued him in a way a clinic never could. Within the heaps of paperwork, he uncovered a compelling combination of science and service. “I didn’t really understand anything about the field,” Pevzner says of his first foray into public health. By uniting disparate fields like psychology and economics, he and his colleagues were finding ways to improve people’s lives. Pevzner never did end up in med school. Instead the research led to a fellowship at the U.S. Centers for Disease Control and Prevention (CDC), which in 2005 ushered him into a more mysterious side of…

THE IMMUNE SYSTEM, WHICH IS MADE UP OF white blood cells, the spleen, and bone marrow, acts like an invisible cavalry in our bodies. When it spots an intruder like a virus, it dispatches Y-shaped antibody proteins that lock on to a particular baddie to mark it for attack. But the strategy isn’t exactly perfect. Sometimes the microscopic defense revolts, and doctors are still baffled as to why. What they do know, though, is that when things go haywire, our internal fighters can destroy healthy cells and organs, causing lupus and other illnesses in at least 20 million Americans. Daniel Davis, a professor of immunology at the University of Manchester, says it’s possible that antibodies end up targeting the wrong bits because certain dastardly germs can resemble human proteins. In…

BEFORE VACCINES, physicians would blow smallpox scabs up people’s noses or stab them with pus-laced needles to build up their resistance to the virus. It usually worked: Patients would feel mildly ill, then grow immune. But because the pathogen was still living inside them, they could spread it to others. By the 1930s, medical researchers had figured out how to breed harmless forms of bugs to stuff into sterilized injections. Since then, vaccines have saved tens of millions of lives, but the pace of development can be glacial. Over the past century, it’s taken an average of 25 years to create a “dead” virus that can protect humans. But when faced with new and rapidly spreading contagions, could a different approach cut that timeline down to just a few months?…

When we were kids, my uncle used to take my cousins and me on trips to Racetrack Playa. Geologists know the flat, dry lake bed in California’s Death Valley National Park for one strange phenomenon: its slithering stones. Since the late 1940s, they’ve been investigating how boulders scattered across the land—some as big as compact fridges—seemingly move thousands of feet on their own. Theories abounded, from the reasonable to the absurd, but no one had ever seen the rocks in action. Death Valley, as its name implies, is inhospitable. Put aside that it’s one of the hottest places on Earth, but it’s also hit by severe winter storms. No one wanted to sit around and watch. But in 2011, my cousin Jim, an engineer, came to me with an idea.…

HERE’S A MIND-BENDINGquestion: Are you reading this because you definitively chose to or because you were destined to? Philosophers have pondered free will’s existence for millennia, and neuroscientists began to consider whether humans go about their lives of their own accord in the 1960s. But it wasn’t until a pivotal 1983 study that anyone had any hard evidence in either direction; researchers asked participants to consciously decide to move a finger prior to raising it and recorded their brain activity with an EEG. Surprisingly, before subjects chose to move, their grey matter lit up, suggesting noggins make determinations before we’re aware of them. Over the years, the finding has been met with scrutiny, as the actual reason for those EEG spikes is still unclear. Modern investigators like Uri Maoz, a…

WITCHES WOULD FEEL right at home within the fan base of a sports team, where curses, hexes, and charms abound. As if compelled by magic, superstitious diehards have worn inside-out good-luck hats called rally caps, planted team memorabilia on Mount Everest’s peak, and displayed butchered goats on stadium grounds—all because they believe it’ll help their treasured team win. These rituals don’t influence the outcome of the match, so why do they exist? Such actions often arise from a place of helplessness, according to Murray State University sports psychologist Daniel Wann. Superstitious practices put fans’ minds at ease because they make them feel as if they have some control over the game. There’s also a bit of peer pressure involved. Studies show that being part of a team’s hype squad offers…

IF YOU FLY OVER THE DESERT on the southern coast of Peru, you’ll spot dozens of line drawings, stretching hundreds of feet across the arid landscape. The Nazca people created these images—​depicting such characters as a whale, a hummingbird, and an astronaut-​esque man—nearly 2,000 years ago. The etchings may have ​served as a massive astronomical calendar or offered tribute to the gods, though their actual purpose still eludes historians. While some suspect alien interference, the methods the Nazca used probably aren’t quite so far-fetched. 1/Planning One theory holds that artists first painted these designs on canvas. They could sketch an image, then scale it up proportionally with some type of grid system, as today’s architects do with blueprints. They’d use poles and rope to map the lines across the desert.…

SOAP, WATER, AND TIME: That’s the recipe for healthy paws. For thousands of years, entire religions and cultures have leaned on the practice for cleanliness, but it’s become more popular in the past two centuries as the sanitizing power of sudsing agents and running H2O have become more clear. Still, is the simple act as effective at thwarting microbes as we think? “Hand-washing is a catchall preventive measure,” explains Emory University epidemiologist Matthew Freeman; it rids our skin of foodborne germs, chemicals, and other undesirable substances. The suds, for the most part, don’t kill pathogens. Soap is a surfactant, which means it makes it easier to clear away oils and dirt. Water then rinses off the contaminants, carrying along microbes for the ride. “By rubbing your hands together, you create…

THE COVID-19 ORIGIN STORY IS MURKY AT BEST.Epidemiologists agree that the disease likely thrived in bats before it made the zoonotic leap to humans—plus pangolins, dogs, cats, tigers, lions, and minks. But that’s about where the consensus ends. Biologists and virologists need to dissect how different creatures interact with germs like SARS-CoV-2, which causes COVID, to understand how public health crises emerge. Part of that means digging into human-wildlife relationships—and how they change as people take over more of the world. We asked the experts where threats lurk as we push those barriers, and what more we need to learn. People are concerned about weird contact in species in the wildlife trade—but the biggest risks are climate change and land use. Both displace animals and cause possible reservoirs of disease.…

1 Headgear The tough thermoplastic shell on the 12-ounce Petzl Boreo Caving helmet will protect the top and sides of your noggin from bumps against hard rock walls. An integrated mount provides a secure spot for a Petzl Duo S headlamp to illuminate your path. 2 Footwear Floors can be slick with running water. Tacky Vibram rubber outsoles on Vasque’s Talus XT GTX boots give you traction on muddy surfaces, while Gore-​Tex membranes keep that H2O at bay. A 2-​millimeter-​thick leather upper guards your feet. 3 Joint protection Wriggling through tight spaces is necessary in most caves—and tough on your knees and elbows. Pads from Gonzo Guano Gear feature neoprene cushioning to shield your bony bits and durable polypropylene webbing that conforms to your body. 4 Backpack Losing your food,…