DiscoverJanuary/February 2019的目錄

To some, sunglasses are a fashion accessory… Drivers’ Alert: Driving in fall and winter can expose you to the most dangerous glare… do you know how to protect yourself? In the fall and winter, the sun is lower in the sky so it rises and sets at peak travel periods. During the early morning and afternoon rush hours many drivers find themselves temporarily blinded while driving directly into the glare of the sun. Deadly accidents are regularly caused by such blinding glare with danger arising from reflected light off another vehicle or snowy and icy pavement. Yet, motorists struggle on despite being blinded by the sun’s glare that can cause countless accidents every year. Not all sunglasses are created equal. Protecting your eyes is serious business. With all the fancy…

In the search for a new planetary home, there’s an important question that experts need to ask: What’s the maximum gravity we could survive? In a recent online story titled exactly that, writer Michael Allen covered a study on the topic. Based on the researchers’ calculations, we could manage on a planet whose gravity is about three or four times that of Earth’s — but only if we train like elite athletes first. Here’s what some readers had to say on DiscoverMagazine.com. Artor Of course, standing upright in 2G is enough to make most people pass out, as all their blood runs to their feet. Some industrial-strength compression stockings would help, but only a little. hisxmark How much a fully developed athlete could endure does not shed much light on…

NOW WHAT? An Adélie penguin waddles up from its colony on Antarctica’s tiny Brash Island for a closer look at a quadcopter, which scientists had landed only about 30 seconds earlier. “Adélie penguins have no natural land predators in Antarctica,” says Stony Brook University Ph.D. student Rachael Herman, explaining why they can be indifferent or curious about human activity. Drones such as this one were novel tools for Herman and her multi-institution team, which determined that the Adélie colonies on this remote island chain were far larger than previously thought. (See page 44 for more about the newly discovered penguin megacolonies.) Turn the page for our special section on the year’s top science and technology news, featuring some of the most memorable images of the year sprinkled throughout.…

Nitro Corn to the (Potential) Rescue! For decades, scientists have tried to coax corn to create its own fertilizer. A team of researchers has found one corn variety, in the southern Mexican state of Oaxaca, that’s been producing its own fertilizer all along. The discovery, published in PLOS Biology in August, could transform how the crop is produced worldwide. Commercial plant fertilizers typically include nitrogen, which helps grow healthy crops but also causes environmental damage. This Oaxacan corn variety develops prominent, fingerlike aerial roots that secrete a carbohydrate-rich goo. The mucilage supports bacteria that convert atmospheric nitrogen into a form the plant can use. If the trait can be bred into other crop varieties, it could mean less nitrogen from artificial fertilizers in the environment — and big cost savings…

Maya Megalopolis For the first time, archaeologists glimpsed the enormity of the Maya civilization, which peaked about 1,500 years ago. Planes flew over 800 square miles of northern Guatemala as an onboard lidar system pulsed lasers downward and measured the reflecting beams, making a 3D scan of Earth’s terrain that revealed archaeological features hidden by vegetation. Some 60,000 previously unknown structures were revealed by the images, says Thomas Garrison, co-leader of the project. The findings tripled population estimates of the Maya civilization to 15 million. The team aims to survey an additional 4,000 square miles. Pathogens of the Past Advances in capturing and reading pathogen aDNA from skeletons led to several breakthrough 2018 studies on ancient human diseases, leprosy and syphilis. In May, two separate teams found hepatitis B sequences…

Big Boost to U.S. Research Spending The U.S. spending plan for the 2018 fiscal year saw the largest single-year increase in the federal research budget since the 2009 economic stimulus package. Research and development spending for 2018 increased by $20.1 billion, or 12.8 percent, compared with spending in 2017. The final bill, crafted by Congress and signed by President Trump, rejected many of his previously proposed science cuts, especially to areas relating to climate and the environment. The legislation also bolsters, after more than 20 years, the CDC’s authority to research the causes of gun violence. Trump Finally Picks Science Adviser In July, Trump tapped University of Oklahoma meteorologist Kelvin Droegemeier to be director of the White House Office of Science and Technology Policy, essentially the president’s top science adviser.…

Light Show In some cases, researchers hoping to discover something new must borrow technology from a seemingly unrelated field. John Delaney, a physicist working at the National Gallery of Art in Washington, D.C., knows this as well as anyone. Working with other physicists, as well as chemists and conservators, the senior imaging scientist has been using spectroscopy to probe famous artwork. This new kind of research is non-destructive, so it conserves existing paintings and sculptures for future generations while revealing secrets about their provenance. Some of the insights he gained into the works of Pablo Picasso this year illustrate the kind of art finds we can expect in the future. In April, Delaney studied Mother and Child by the Sea, Picasso’s 1902 painting. Near-infrared imaging revealed the unmistakable shapes of…

March 17 Newspaper investigations reveal Cambridge Analytica, a data consulting firm, harvested the personal data of around 87 million Facebook users. The company analyzed an individual’s networks and “likes” to better target political ads, and used that info to advise politicians’ campaigns. March 25 In a public letter, Facebook founder and CEO Mark Zuckerberg apologizes for his company’s role in the data mining. April 10 Zuckerberg testifies before Congress about Facebook’s privacy safeguards and Cambridge Analytica. May 2 Cambridge Analytica announces it’s closing shop. (However, former analysts with the company had already launched a similar firm, Data Propria, in February.) May 25 The European Union institutes its sweeping General Data Protection Regulation, which was years in the making. Facebook and Google are accused of failing to follow the guidelines for…

We’ve all seen it. One week a headline will tout the health benefits of, say, drinking a little red wine each day. Give it a few months, and we’ll all groan as we catch another headline that declares a daily glass of wine is a no-go. What those fleeting headlines lack is context. How does that one study that’s grabbing all the coverage today really fit into the greater landscape, as researchers strive to answer questions? That’s the thinking behind The State of Science — our take on the year’s biggest discoveries. Because we grouped scientific findings by field, you’ll have a chance to sink in and see where each story fits in the larger space of inquiry. We hope to give you a sense of the state of each…

Antarctic researcher Robert Schwarz knew last July’s lunar eclipse would be something special. Not only would Earth’s shadow pass over the moon, but Mars was also unusually big and bright in the sky, making for a cosmic double feature. To capture Mars as it shone above the eclipsed moon at the South Pole, Schwarz spent several frigid hours outside in 25-knot winds, withstanding temperatures of minus 50 degrees Fahrenheit. The astrophysicist’s day job, conducted in much warmer conditions, involves studying the cosmic microwave background — the Big Bang’s leftover energy — using the Keck Array telescope, which is housed within the Spirex Tower that appears directly below Mars and the moon.…

Carbon Rising In May, an observatory in Hawaii measured Earth’s atmospheric carbon dioxide levels at 411 parts per million — the highest monthly average recorded in modern times, and a level the planet hasn’t seen in at least 800,000 years. Hothouse Earth The consequences of surpassing a 2-degree Celsius increase in global temperature isn’t just widespread crop failures, record-setting heat and rising seas. An August PNAS study says it could also tip the planet into new, irreversible climate patterns. Current Weakening The Atlantic Meridional Overturning Circulation (AMOC) moves streams of warm and cool water between the tropics and Greenland, helping regulate Earth’s climate. These ocean currents slowed to a record low in 2018. Without a strong AMOC, we can expect more summer heat waves in Europe, sea level rise on…

It’s All Relative Computational biologists have created the largest family tree ever, packed with a whopping 13 million people — including Kevin Bacon — over five centuries. Reporting in March in Science, researchers used public genealogy profiles to assemble the massive pedigree. They found longevity is probably less genetically determined than previously thought. But the tree’s real utility may be yet to come. Adding genetic and health information could reveal much more about what causes certain diseases. Protein Therapy Goes in Utero For the first time, doctors used a drug to treat a genetic disease before birth. People with XLHED can overheat because they lack a protein critical for sweat gland development. In an April study, doctors in Germany, Switzerland and the U.S. described flagging three fetuses as having the…

Neanderthals, They’re Just Like Us Let’s retire, once and for all, the outdated notion that Neanderthals were dumb brutes, an idea that’s stuck despite a raft of contrary finds over the last decade. In 2018, a trio of studies from separate teams unearthed yet more evidence that our closest evolutionary kin were capable of complex abstract thought, including symbolic art (February, Science), cooperative big-game hunting tactics (June, Nature Ecology & Evolution) and the production of fire using stone tools (July, Scientific Reports). First-Generation Human Hybrid Researchers recovered the genome of a teenage girl, who lived about 90,000 years ago, from an inch-long splinter of bone found in Denisova Cave in Siberia. Her mother was Neanderthal and her father was Denisovan, another species of extinct human. While geneticists have previously uncovered…

Learning to Speak Neutrino We’re figuring out how to see the cosmos in a new way. For centuries, humans learned about the universe with just their eyes, observing in visible light. We eventually developed technology to see in other wavelengths of light — infrared, X-ray, gamma ray — to discover even more about the universe. Now, thanks to two papers in Science in July, astronomers can see with neutrinos, too. Neutrinos are thought of as ghostly particles because they interact so little with matter. Trillions of the subatomic things pass through your body and the rest of the planet every second, without disturbing any atoms. This indifference to anything in their way makes them ideal for astronomers hoping to understand the extreme environments that can produce them and other interesting…

February Merck stops Phase 3 trial on BACE1 inhibitor verubecestat. The move comes a year after an earlier trial in which patients showed lowered beta-amyloid levels, but with adverse effects and no improvement in brain function. February Biogen tweaks design of its trial for the antibody drug aducanumab. May Janssen shuts down its trial of BACE1 inhibitor atabecestat because of safety concerns. June Biogen and Eisai reveal that their BACE1 inhibitor elenbecestat lowers beta-amyloid levels, but they can’t claim the drug boosted people’s cognitive function any better than a placebo. July Biogen and Eisai report promising results for their antibody drug BAN2401. Users of all dosages saw drops in beta-amyloid beta levels, while those using the trial’s highest dosage also experienced improved cognitive function.…

Net neutrality rules, which barred internet service providers from blocking or slowing access to content of their choosing, expired in June after the Federal Communications Commission repealed them in late 2017. Supporters of net neutrality are concerned that this could threaten the free and open nature of the internet: The net neutrality regulations may have had room for improvement, but repealing them altogether eliminated protections that kept service providers from favoring wealthier users and potentially discriminating against those who can’t afford to pay for better services. Discover spoke with Johannes Bauer, a researcher at Michigan State University who studies how management of information technologies — like net neutrality rules — affects society. Q How might the lack of these net neutrality regulations now affect us as individuals and as a…

Repulsive Attraction Engineers from the University of Minnesota reported in Nature Communications in May on ruthenium’s newly discovered magnetic properties. The element is only the fourth in the periodic table — after iron, cobalt and nickel — known to be susceptible to magnetism at room temperature. Spaghetti Solution In August, researchers at MIT answered an enduring pasta conundrum: Is it possible to snap dry spaghetti, cleanly, into just two pieces? Yes, but you have to twist it approximately 270 degrees as you bend, easier to write than do. The find should help engineers better predict stress failures in rods, from pillars to nanotubes. A Criminal’s Cancer According to a July paper in Trends in Genetics, chemists can now analyze the molecular tags attached to DNA found at crime scenes, potentially…

Space Chats Chinese and Austrian scientists announced in January they’d successfully tested the first satellite-based network that used quantum encryption to secure transmissions between ground-based and satellite stations, proving the technology’s viability. They sent each other images and hosted a 75-minute video chat. Blockchain Bonkers In 2018, we saw more than 50 new cryptocurrencies, which bypass ordinary banks and could offer owners quick accelerations of wealth — or a steep dive to the poorhouse. The price of a Bitcoin, the original cryptocurrency, soared above $19,000 in 2017. But after months of wild swings, it was trading at around $6,500 in October.…

Underneath It All (“The Sleeping Giant,” September 2018) Discover’s photos and schematics are spectacular! The Crux, which showed Antarctica minus the ice layers, satisfied my lifelong desire to see what’s under all that ice. Please do one for the Arctic next. Carole JoslinSunrise, Fla. Make the Call (“Pyramid Dreams,” September 2018) I’ve loved reading your articles about the lost pyramids of Bosnia. I don’t understand why the European Association of Archaeologists wouldn’t want to prove Sam Osmanagich wrong and put this idea to rest once and for all. It could easily be done. Just have an archaeology doctoral candidate do his thesis on these pyramids. They could use ground-penetrating radar to discover if it’s just a hill, or maybe a temple built by the Romans, or the lost tomb of…

ON AN INTERCONTINENTAL FLIGHT several years ago, Harris Lewin decided to find the common ancestor of all complex life on Earth, from slime molds to his fellow passengers. As a professor of evolution and ecology at the University of California, Davis, Lewin knew what he’d have to do to travel back billions of years in evolutionary time and study this enigmatic progenitor: generate a DNA sequence for every species alive today. It would be a worldwide equivalent of the Human Genome Project (HGP), which fully mapped the DNA of our species in 2003. Lewin took out a pencil to calculate the cost. “I couldn’t believe the number,” he recalls. At $3 billion, the estimate was well within the price range of today’s moonshot science, and considerably less, adjusted for inflation,…

My husband, even in his most sleep-deprived state, never complained about “daddy brain.” But, although fathers’ memories seem unaffected, their brains change in other ways. Levels of the hormone testosterone decrease within the first month of fatherhood, and dads who spend more time with kids have lower levels of the hormone, according to a 2011 study in the journal PNAS. Though men might think of the drop as a knock to their manliness, it can be a good thing. In families in which fathers have higher levels of testosterone, mothers report more marital dissatisfaction and spousal aggression. So it seems the dip is evidence that male brains adapt for parenthood to help support their family. And just like in moms, dads see growth in brain regions involved in parental motivation.…

ICESat-2 In September, NASA launched the Ice, Cloud and Land Elevation Satellite-2. Using laser pulses, ICESat-2 will measure changes in Earth’s ice over the next three to seven years. GRACE Launch On May 22, NASA’s latest GRACE spacecraft — a “follow on” to the original Gravity Recovery and Climate Experiment — launched to monitor Earth’s water, from underground stores to oceans and ice.…

CRISPR’s Roller Coaster Safety Ride The genome-editing tool CRISPR-Cas9 is revolutionizing the field of medicine. The technology, which took off in popularity among researchers about five years ago, can precisely edit DNA. The system includes two components: a DNA-cutting enzyme, called Cas9, and a piece of RNA, called guide RNA. A bit of guide RNA targets a specific chunk of DNA, directing Cas9 exactly where in the genome to snip. But slicing and dicing DNA isn’t without risks. Some researchers have been wary from the get-go, perhaps rightly so as details emerge about CRISPR’s sometimes-troubling safety record. The pro-CRISPR camp scored a win in March, when Nature Methods retracted a 2017 paper that had stirred controversy. The researchers originally said their CRISPR-edited mice had large numbers of so-called off-target mutations…

How to Build a Brain The human brain is a big deal. In relation to body size, it’s nearly six times bigger than that of other placental mammals. Our brains’ size and organizational complexity are hallmarks of being human. But what were the genetic changes behind our big, complex brains, and what drove their evolution? Key new evidence, and a new model, move us closer to finally figuring it out. In May, a pair of papers published by separate teams in the journal Cell focused on the NOTCH family of genes, found in all animals and critical to an embryo’s development: They produce the proteins that tell stem cells what to turn into, such as neurons in the brain. The researchers looked at relatives of the NOTCH2 gene that are…

In May, for the first time in over 50 years, fissures opened and lava poured from the lower East Rift Zone of Hawaii’s Kilauea volcano. A July flyover revealed a stark contrast in the landscape: Winds blew heat and gases southwest from an active lava channel, severely damaging vegetation to the south (at left) but sparing land to the north (foreground). By mid-August, lava traveling across the Big Island’s southeast corner destroyed at least 700 homes and filled in an entire bay, adding 875 acres to the island.…

A column of Greenland ice has offered insight into the politics and economics of ancient Rome. Layers of Greenland’s ice contain lead and other metals that had drifted hundred of miles from Europe between 1235 B.C. and A.D. 1257, according to a May paper in PNAS. Researchers found that fluctuations in the lead measurements matched historical records of changes in European metal production related to wars, epidemics and imperial expansion. Researchers have previously studied lead in ice cores using a time-intensive method that provided less precise information. The instrumentation used in the new study, however, is faster and able to produce far more complete data. By sampling a column of ice from the center of a larger ice core, the new method also reduces the risk of contamination from modern…

Bees Know Nothing An international team of researchers trained 0 < 1 honeybees to learn the numerical concepts of “greater than” or “less than” and concluded that the insects seemed to grasp the concept of zero. “Bees demonstrated an understanding that parallels animals such as the African grey parrot, nonhuman primates, and even preschool children,” they observed in a June Science paper. Our Cells, Our Scutoids In July, a team of biologists unveiled the scutoid — a newly identified shape that emerges when the cells of biological tissue are Christopher packed closely Hacon together.…

Dinosaur Sported Iridescent Feathers A 160 million-year-old feathered dinosaur from northeastern China may have shimmered like modern hummingbirds. Researchers describing Caihong juji in Nature Communications in January found vestiges of its melanosomes, cellular structures that, in feathers and skin, can determine pigmentation patterns. Comparing Caihong’s melanosomes with those of modern birds, the team concluded that the flashy dino had multicolored, iridescent feathers on its head, tail and wings. Using fossilized melanosomes to determine what extinct animals may have looked like is a growing trend, but in July another Nature Communications study urged caution. Melanosomes occur throughout the body, not just in the skin and feathers, and can shift around during decomposition, making it tough to determine an animal’s true colors. Origins of the First American Pooches Did the first humans…

Flames engulf Brazil’s National Museum in Rio de Janeiro in early September, as horrified onlookers watch helplessly. The blaze destroyed most of the roughly 20 million items in the collection, the largest in South America and more than twice as big as that of the British Museum. Artwork, unique fossils, zoological specimens and entire cultural histories were lost. Severe funding cuts for maintenance in recent years likely contributed to the fire’s intensity, and the institution’s future is uncertain. What is clear: The devastation is a tragedy not just for Brazil, but for the world, and a serious blow to science.…

Approaching Quantum Supremacy Tech experts have long championed quantum computers as the next generation of machine, promising to solve big problems in lightning-fast time, but the delicate chips exist in only a handful of labs. In the race to build the largest one yet, Google shot ahead in March when it unveiled Bristlecone, a 72-qubit device with low error rates. The previous record holder was a 50-qubit IBM machine. Qubits do for quantum computers what bits, usually stored on transistors, do for classical computers: They carry out computations and store information. But unlike traditional bits, which can take one of two values (on/off, or 1 or 0), qubits can exist in a combination of two states at the same time, allowing for greater digital brainpower. The more qubits, in theory,…

CITY SLICKERS ➜ MIT researchers unveiled a mesh that uses electric fields to attract and condense water in fog. ➜ The researchers say it will capture 150 million gallons of clean water per year from the discharge of industrial cooling towers, like the ones on rooftops that expel heat from air conditioning. ➜ A pilot test on a cooling tower at MIT is under construction and should be operational in 2019. HEAVY METALS ➜ A team from the University of California, Berkeley, invented a harvester that uses a highly porous metallic powder to collect water at night. ➜ During experiments in the Arizona desert, each kilogram (about 2 pounds) of powder reportedly produced nearly half a cup of water every 24 hours. ➜ The team has already scaled up the…

1 Across the nation, we were deeply divided…between those who heard “laurel” in a sound clip and those who insisted it was “yanny.” The actual word in the audio file, circulated on social media in May, was “laurel.” (Sorry, Team Yanny.) 2 The word perceived in the low-quality recording of an online pronunciation guide depended on factors such as whether a listener’s hearing was biased toward low or high frequencies, according to a Current Biology study published in July. 3 Such auditory illusions are essentially our brains trying to make sense of ambiguous information. Want a little more brain ambiguity? Paleoanthropologists are rethinking a basic idea about how our gray matter evolved. 4 Modern human brains are exceptionally large and complex, and researchers assumed size came first, or at least…