Indholdsfortegnelse for January/February 2021 i Discover

SOME 60 MILLION light-years from Earth — by the estimate of one team of researchers, anyway — a pair of strange galaxies is causing a cosmic stir. The bizarre galaxies, named NGC 1052-DF2 and NGC 1052-DF4 (or DF2 and DF4, for short), are the first known galaxies born without any significant amount of dark matter. If confirmed, their existence would throw a wrench into our understanding of how galaxies form and evolve. But, as Carl Sagan liked to say, extraordinary claims require extraordinary evidence. And, according to some researchers, the evidence for these dark-matter-deficient galaxies doesn’t hold up. THE CLAIM: NOTHING TO SEE HERE Astrophysicist Pieter van Dokkum of Yale University was certainly surprised when he first spotted DF2. After data from the Dragonfly Telephoto Array, the Sloan Digital Sky…

WOULD THE WORLD be a better place if people read more fiction? Words on a page can introduce us to what it’s like to lose a child, get swept up in a war, be born into poverty or leave home and immigrate to a new country. A growing body of research has found that people who read fiction tend to better understand and share in the feelings of others — even those who are different from themselves. The results hold up even when comparing fiction to non-fiction readers. In 2006, researchers found that the more names of fiction authors that participants knew — and the more fiction they presumably read — the higher they scored on empathy tests. Since then, exploring the intersection between empathy and fiction has caught on…

Dec. 31, 2019 China reports a cluster of atypical pneumonia cases in Wuhan, Hubei province. Jan. 12, 2020 After ruling that the outbreak was caused by a novel coronavirus, China publicly shares the genetic sequence of SARS-CoV-2. Jan. 13, 2020 The World Health Organization (WHO) reports the first case outside of China, in Thailand. Jan. 20, 2020 WHO officials determine there is “at least some” person-to-person spread happening in Wuhan. Jan. 21, 2020 North America reports its first confirmed case of COVID-19 — a U.S. patient who had recently returned to Washington state from Wuhan. Jan. 24, 2020 Three cases are reported in France, all from people who recently traveled to Wuhan. These are the first cases recorded in Europe. Jan. 25, 2020 Australia announces the continent’s first case, after…

THE WELSH VILLAGE of Llandudno went quiet in March as stay-at-home orders began. Then the goats descended from the mountain. A wild herd of Kashmiri goats has lived near Llandudno for almost two centuries, and they sometimes come down from the Great Orme Mountain during inclement weather. But this spring, while the human world hit pause, they settled into town for a few days, munching on hedges and trotting down the empty streets. The goats joined a host of animal celebrities flooding the internet after they supposedly reclaimed urban areas: dolphins frolicking in Venice’s clean canals, elephants drunk on corn wine in a tea garden in China’s Yunnan province. Tweets announcing these events proclaimed that nature was recovering from years of abuse by humans, thanks to COVID-19 shutdowns. While the…

SPINOSAURUS AEGYPTICUS is a fan favorite, its sail-backed shape appearing everywhere from museums to a starring role in the Jurassic Park franchise. In April, paleontologists announced a fossil that further solidified its image: The discovery of a long, paddlelike tail marked Spinosaurus as the first known semi-aquatic dinosaur. The current model of Spinosaurus took over a century to assemble. In 1915, German paleontologist Ernst Stromer named Spinosaurus, a carnivorous dinosaur that stalked Cretaceous Egypt and bore a tall sail on its back. But, not long after the dinosaur’s description, the only known fossils were destroyed during a 1944 Allied bombing raid of Munich. Spinosaurus was lost to science. Bits and pieces turned up over the following decades. Scraps bobbed out of the strata of Egypt and turned up in Morocco’s…

THE FOSSIL was heralded as the smallest dinosaur ever found. Named Oculudentavis and known from a skull encased in 99-million-year-old amber, the living animal would have been about the size of the smallest modern hummingbirds. Strange, then, that such a tiny fossil stirred the largest paleontological controversy of the year. From the time of the fossil’s March publication in Nature, outside experts were skeptical of the animal’s identity. The initial analysis by paleontologist Lida Xing and colleagues couldn’t pin down where Oculudentavis fit in relation to other dinosaurs; if anything, the fossil had characteristics that were both primitive and advanced for a dinosaur of its age. Rumors began to spread that there was a second specimen of the same animal that confirmed the creature’s identity as a lizard. Then, on…

AS THE ARC of coronavirus misery rose in 2020, a hopeful development on another dangerous curve may have escaped your attention. The curve tracking the rise of global carbon dioxide (CO2) emissions from energy use went totally flat in 2019, according to a report released in February by the International Energy Agency (IEA). Another international report found very slight growth in global emissions during the same time span, compared with prior years. Either way, this flattening happened before COVID-19 temporarily hampered economic activity and carbon output. So, the promising CO2 trend stems from other factors: plunging use of coal in many economies and gains in renewable energy, according to the IEA report. “We’re flattening the curve, which is the first step toward bending it downward,” says Michael Mann, a climate…

THE MARINE CORPS Air Station Miramar, near the sunny coast of Southern California, is partially solar powered. Distributed across 24,000 acres, the solar grid is self-contained and secure, but energy production can drop precipitously when storms roll in — with no way to ramp the panels’ electricity production up or down in sync with the weather. But earlier this year, the Marines enlisted a technology more commonly associated with a brand-new Samsung Galaxy than a military compound: The station contracted Verizon to build a private 5G cellular network. The fifth-generation standard for cellular communications, 5G has generated buzz since it was codified in 2017, beguiling consumers with visions of seamless videoconferencing and video-game streaming. Each of the five generations of cellular has changed society in different ways, with distinct technical…

A WARMING WORLD, AND A STRANGER ONE: Natural disasters are a normal part of life on Earth, but 2020 layered historic levels of devastation on top of the COVID-19 pandemic. In North America, massive wildfires seared parts of the western U.S. from late summer into fall, forcing more than half a million people to evacuate in the midst of the health crisis. A derecho — an intense windstorm sometimes referred to as an inland hurricane — pummeled parts of the Midwest in August with 100 mph winds. Hurricanes slammed the Caribbean and southern U.S. starting in June, causing flooding and extensive damage. Meanwhile, the pandemic made disaster relief an even more precarious process. Scientists say many of the increasingly severe and compounding events are no fluke of a cursed year…

GERRY MARTIN is one of India’s most well-known herpetologists. In 2011, he traveled to a remote area in Arunachal Pradesh, considered India’s wildest frontier, to collect venom. During a nighttime outing, he came across a small, lime-green snake called Trimeresurus medoensis, commonly known as the Medo pit viper. The snake can be found in hilly areas of China, India and Myanmar. But key traits, like population size and venom toxicity, remain little understood. Martin grabbed the snake by the tail for collection, and quickly learned more than he ever hoped to know. IN HIS OWN WORDS: While I was readying the collection bag, the viper bit my pinky. My colleague made a sling out of his jacket and we walked over a kilometer back to the village. The finger began…

The past year unfolded like a dark satire: natural disasters, racial violence and the virus that would not quit. To set the stage for 2021, we turned to experts. Here’s their mile-high view of coronavirus and the biggest science stories it eclipsed in 2020.…

The COVID-19 pandemic likely plunged you into a world — specifically, the world of vaccine development — that you didn’t know much about before. Maybe you’ve learned that vaccines typically take years to produce. Or maybe you’ve found yourself wondering how the roughly 200 SARS-CoV-2 vaccines in development are supposed to work. Essentially, a vaccine needs to trick your immune system into thinking there’s an infection. That way, you’ll develop an arsenal of tactics to kill off the pathogen, should it ever show up in your body. Live vaccines release a somewhat nonfunctional version of the virus into the body. If researchers tamper with it just right, the modified virus can still provoke your immune system without getting you sick. One way to sap a virus of some of its…

IN MARCH, LABS around the world went dark. Experiments stopped, specimens were frozen and research timelines shifted into the unknown. By the time labs began reopening, a new mode of science had emerged. It only took a microscopic virus to bring macro-level changes — some good, some bad and many with no signs of turning back. 1 FASTER. The technology of the 21st century has allowed science to move forward virtually — and rapidly. The latest COVID-19 findings are shared online at warp speed, and media reports are delivered straight to smartphones in the palm of our hands. While this barrage of research fosters speedy discoveries, some scientists are concerned about the consequences of too much haste. In May, Jonathan Kimmelman, a bioethicist at McGill University, co-authored a commentary in…

MOST OF THE crew aboard the RV Polarstern icebreaker was asleep when the Arctic Ocean ice they were frozen into fully dissolved in late July. Researchers had called the ship home for 10 months — and this was not part of the plan. The team of pilots, climatologists, oceanographers and others had deliberately frozen the ship into the ice floe north of Siberia in October 2019. Their mission: Drift for more than 365 days with the floe and surrounding sea ice to study the Arctic climate. With roughly 600 experts from around the globe, and a cost topping $150 million, the Multidisciplinary drifting Observatory for the Study of Arctic Climate (MOSAiC) is the biggest, most elaborate Arctic expedition ever “Our mission is to observe and understand the climate processes of…

YES, SCIENTISTS ACTUALLY INJECT DNA that contains the instructions for the CRISPR complex into a human eyeball. This DNA is packaged inside deactivated viruses that shuttle them straight into the cells of the retina. Once inside, the cells read the genetic code and create the CRISPR editor, which, in turn, edits the mutated gene that was preventing CEP290 production.…

EVERY SPRING, rains and snowmelt swamp vast grasslands that stretch between the Andes Mountains and Amazon rainforest in northern Bolivia. But thousands of tree-covered mounds stand solid, several feet above the flooded grasses. “They are like islands in a sea of savannah,” says Umberto Lombardo of the University of Bern, Switzerland. In 2006, Lombardo first stepped onto a forest island in this Llanos de Moxos region, puzzling over how such features could form naturally. “As a geographer, I had absolutely no explanation for them,” he recalls. One theory suggested that over the past few centuries, ranchers had carved away lush rainforest to create pastures, but left scattered groves of about 300 trees each. Yet that didn’t explain why the trees grew on higher ground. It turns out the forest islands…

EXHAUST PIPES and power plants spew tiny particles 2.5 microns in diameter or smaller into the air we breathe. Thousands of them could fit on the period at the end of this sentence. And recent studies show that long-term exposure to this fine-particle pollution at levels far below what current EPA standards allow is associated with premature death. Yet some researchers, including the current chair of the EPA’s Clean Air Scientific Advisory Committee, declined to revise the National Ambient Air Quality Standards (NAAQS) in April. They argued that because the researchers conducting the studies used traditional statistical approaches that rely on assumptions, they failed to show causality. Harvard University scientists responded by publishing a June Science Advances study that comes as close to showing causality as air pollution researchers can…

TO MANY, Earth feels like a static place. The rock beneath our feet seems solid and unchanging. Yet, over billions of years, the surface of the Earth has actually changed dramatically and its interior composition altered, all thanks to plate tectonics. Shifting plates of crust move on thick layers of flowing — but still solid — rock called the mantle. This constant shifting not only moves continents, but also recycles material from the surface back towards the planet’s deep interior. Scientists are continually investigating exactly how long the plates have been active. Did they start shortly, geologically speaking, after our planet’s formation, or billions of years later? If that movement started early, was it anything like what we see today? Scientists have proposed strange theories like drip tectonics, where plates…

IMAGINE GAZING up at a dark sky on a clear summer night and seeing more satellites crawling across the heavens than stars. That could soon be a reality: A small group of companies is working to launch so-called satellite mega-constellations to provide global high-speed internet that will leave current satellites in the dust. Amazon got approval in July to launch its satellites; others, including SpaceX and the U.K.-based OneWeb, have already started. “We’re seeing the beginnings of a new industrial revolution in space,” says Jonathan McDowell, an astronomer at the Harvard-Smithsonian Center for Astrophysics who published one of the first studies of the impact of these satellites. “This is a phase change. We’re going from hundreds of satellites in low-Earth orbit to potentially tens of thousands.” In 2020, SpaceX turned…

MISSION: MARS SUPPORT NASA pilots Troy Asher and Stu Broce are masked up and mission ready as they step up to their next flight. Normally, they fly planes such as a modified Gulfstream jet, brimming with data-collection instruments for the agency’s airborne science research. But when COVID-19 grounded those missions, pilots like Asher and Broce got new orders: Shuttle personnel from California’s Armstrong Flight Research Center (above) to Kennedy Space Center in Florida, so they could ready the newest Mars rover, Perseverance, for launch. Those efforts paid off when the robotic explorer set out on its sevenmonth voyage to the Red Planet on July 30.…

THE FIRST TIME biologist Heather Masonjones heard about the seahorses on Eleuthera Island, she had trouble believing in a place where seahorses were as common as other fish. After 29 years studying the animals, the University of Tampa seahorse expert had never seen more than a handful together underwater in her whole career. But once she was immersed in the emerald waters of the mile-long Sweetings Pond, which sits on a narrow crescent of an island in the Bahamas, she started to believe the hype. “It was an absolutely magical moment,” she says, adding that she saw 16 of the animals in several dives during the first weekend in the water there — an enormous amount, given she had only ever seen three or four in a single dive or…

TODAY, ABOUT 4 billion people — more than half the world’s population — reside in urban settings. But urban life began some 6,000 years ago, when tens of thousands of people first crammed together in one place. Which ancient city rose first? Cities began popping up in the Indus Valley of present-day Pakistan and India more than 4,000 years ago, in China over 3,000 years back, and in Central America in the centuries straddling 1 B.C. and A.D. 1. But the earliest were in the Middle East. About 10,000 years ago, soon after farming began in ancient Mesopotamia, the site of Jericho in the present-day West Bank featured massive stone walls, enclosing a settlement of an estimated 2,000 to 3,000 residents. By 9,000 years ago, Çatalhöyük, located in present-day Turkey,…

NOTHING TURNS the public eye to science quite like a global health crisis. By the time the World Health Organization declared COVID-19 a pandemic in March, people across the world were looking to experts for answers. Where did the novel coronavirus SARS-CoV-2 come from? How can we stop the spread and save the lives of those infected? In many places, people listened — taking up 20-second handwashing, mask-wearing, 6-foot physical distancing and staying home whenever possible. Some of these communities “flattened the curve” of the virus’ spread so much that entire nations were flirting with normalcy by late summer. A resurgence hit numerous places in the fall, while many areas that resisted public health guidelines never saw a break in steady cases. Regardless of the politics and people around the…

IT ALL HAPPENED SO QUICKLY. In a matter of weeks, our world was upended when a far-flung outbreak spiraled into a genuine pandemic. With vaccines and pharmaceutical interventions still a speck on the horizon, human behavior has become a key factor in battling the disease. The crisis has also pummeled both individuals and society itself with a plethora of mental health burdens, from stress and anxiety to social isolation. Research on COVID-19’s psychological impact is still evolving. But by midsummer of 2020, call counts had spiked up to 10 times more than pre-pandemic levels at the Disaster Distress Helpline, a federal hotline for mental-health crisis, according to the American Psychological Association. For decades, social and behavioral scientists have been examining the toll of long-term loneliness, the difficulty of behavior change…

LAST SPRING, a report from the world’s largest neutrino telescope — a sprawling grid of detectors woven into Antarctica’s ice — coincided with a blaze of hyperbolic headlines. They teased the possibility of an anti-universe where, from our point of view, time runs backward and the Big Bang represents an end, not a beginning. While it’s too soon to start searching for our reverse-aging, other-handed doppelgängers, physicists are still wrestling with strange signals coming in from space that, to date, have defied easy explanation. The signals were flagged by a NASA-funded collection of horn radio antennas held aloft over Antarctica by a giant balloon. The device, called the Antarctic Impulsive Transient Antenna (ANITA), picks up radio signals produced when high-energy particles coming from deep space encounter our atmosphere. Some waves…

AN ESTIMATED 32 million Americans have food allergies — nearly 10 percent of the population, and 10 times the prevalence reported just three decades ago. Among children, emergency room visits for the severe, potentially life-threatening reaction known as anaphylaxis are skyrocketing. But new hope arose in January, when the Food and Drug Administration approved Palforzia, the first drug designed to desensitize patients to an allergenic foodstuff — specifically, peanuts. The medication, approved for kids aged 4 to 17, consists of a standardized dose of powdered peanut protein, which can be mixed into snacks like pudding or applesauce. Over time, patients receive increasing amounts until they can tolerate the equivalent of two peanuts without serious symptoms. Palforzia isn’t perfect. It’s expensive (list price: $890 a month), it must be taken indefinitely,…

1 Inside almost every cell in our bodies, there are tiny organelles called mitochondria. 2 The cell’s powerhouse, mitochondria create the molecules our bodies use for energy. They also have their own DNA, separate from the rest of the genome that resides in a cell’s nucleus. Scientists think they were once bacteria that established a symbiotic relationship with our cells. Over time, they lost the ability to live separately and became forever entwined with our bodies. 3 Unlike the rest of our DNA, the mitochondrial genome forms a loop. It’s also small, containing just 37 genes. Mutations to this mtDNA are responsible for a number of rare, dangerous genetic conditions. Like the other DNA in our cells, mtDNA is made of nucleotide pairs. Just four molecules make up all of…

FOR EIGHT YEARS, a crunched cranium protruded from an excavation pit in South Africa’s Drimolen Cave. Archaeologists ignored the fossil, assuming it to be a baboon, until they swept up pieces that had crumbled free in 2015. Early on, the remains looked more human than monkey. Jesse Martin and Angeline Leece, researchers at Australia’s La Trobe University, jigsaw-puzzled together more than 150 bone bits, each no bigger than a quarter. Some were so fine that light shone through. Analysis confirmed the fossil wasn’t baboon. Then, in 2018, another skull surfaced at the Drimolen site, and chronometric dating placed both craniums around 2 million years old. The researchers published their big news in Science this April: Based on skull shape, the second cranium belonged to Paranthropus robustus, a Lucy-like relative with…

CROUCHED IN the rocky confines of the asteroid belt between Mars and Jupiter, an icy sphere the size of Texas has been hiding a secret. This dwarf planet, called Ceres, is actually an ocean world, astronomers revealed in 2020. And it’s far from the only one: Scientists have found the best evidence yet that Pluto (also located in a distant part of the solar system strewn with small space rocks) has an active underground ocean, as well. The search for alien life is really a search for water, and half a century ago, Earth’s oceans seemed unique. But in recent decades, evidence of liquid water oceans has emerged in dribs and drabs at places like Europa and Enceladus, the icy moons orbiting Jupiter and Saturn. Astronomers say they’re piecing together…

IT WAS A GRISLY scene: a hive of decapitated honeybees, their heads chewed off. And it signaled to scientists that thumb-sized “murder hornets” native to Asia had invaded the Pacific Northwest. The finding in the fall of 2019 suggested that a new generation would emerge come spring. By May 2020, the hornets swarmed into the public consciousness via viral news stories and ensuing internet memes that disappeared nearly as quickly as they emerged. The hornets themselves weren’t gone, though — they were lurking underground. Only a handful of Asian giant hornets were spotted in the spring: These were new queens, awake from hibernation and looking for spots to build underground nests. Once they set up shop, they stayed in, laying eggs. Those hatched worker hornets, which emerged in the summer.…

THE ADVANCED Laser Interferometer Gravitational-wave Observatory (LIGO) can measure giant ripples in space-time that race across the cosmos. But in 2019, physicists used it for something else: to measure fluctuations at the quantum scale that jiggle the detector’s super-sensitive mirrors. They published their report in Nature in July. Theorists have long predicted this behavior at the interface of light and matter, but this study is the “first to experimentally prove it” at such large scales and at room temperature, says physicist Haocun Yu of the MIT Kavli Institute, who worked on the project. It’s also the first time that scientists have quantified these quantum effects. These measurements, they say, will improve gravitational wave detectors and other instruments that are influenced by quantum noise. According to quantum mechanics, the subatomic realm…