DiscoverApril 2018的目錄

Just because we were in the dry mountain West — where the growing season is ridiculously short — that didn’t stop my parents from building a huge garden. Rows of zucchini, peas, potatoes, broccoli and (to my and my brother’s dismay) spaghetti squash filled nearly half the field in front of the house. A mass of raspberry bushes, dripping with fruit, meant we’d have jam for months to come. It was the mid-1970s, and meat and dairy was expensive, so that garden was their solution for affordable food. They had altered their environment. You might say alterations — whether it’s the environment, materials or the mind — is a theme in this issue. Associate Editor Eric Betz takes us to Florida, where farmers and scientists are exploring the use of…

ASTROPHYSICIST JEAN-PIERRE LUMINET didn’t have a supercomputer when he showed the world what a black hole looks like. He just had an IBM 7040 and a bunch of punch cards. He knew from theory that black holes do not emit light. But the material that swirls around them — dust and gas stripped from stars — shines all the way to its inanimate death. Light from that material, Luminet thought, would trace the black hole’s shape, including warps in space-time from its extreme gravity. When the fridge-sized IBM spit out results in the late ’70s, Luminet used ink and pen to plot out an image by hand. He saw the black hole’s event horizon, the point beyond which nothing can escape; and an accretion disk, the gathering of matter siphoned…

By the time he reached Los Angeles, Landry was scared, dazed and exhausted. Flying for the first time in his life, the 13-year-old from Cameroon was now some 8,200 miles from all things familiar. Landry, whose parents had recently died in a car crash, came to LA to live with his legal guardian. Although Aunt Delphine welcomed him warmly, Landry’s first night in America was restless. His left ankle was puffy and warm. He settled in to his new environment, attending school and studying English while speaking French and Cameroonian pidgin at home. He played soccer and watched YouTube videos on his cellphone. But his ankle and lower leg continued to swell on occasion. “In the hospital where I work,” Delphine, a certified nursing assistant, told Landry, “elderly people can…

PRINT FEEDBACK Looking for Lost Languages (“My Forgotten Language,” November 2017) I was born in Ceylon, Sri Lanka, and left for Norway at the age of 3. At 4, I went to Geneva where I had most of my education. During my life, I spoke Tamil, Singhalese, Norwegian, English, French. I learned German and finally Portuguese while in Brazil. I have completely forgotten the first three languages and have had no further exposure to them. Still, I believe I have some remains of each. I have a little frustration regarding my lost languages. I can only identify them when I hear them on the streets. Besides a very few words which I can recognize, nothing else is left. I hope to one day learn them back. Kemal Deen Pallie, Sri Lanka…

While tardigrade toughness is the stuff of legends, we don’t often see the micro-animal’s humble beginnings. This embryo was just 2 days old when University of Kassel Ph.D. student Vladimir Gross photographed it at 1,800x magnification. This creature, only a fifteenth of a millimeter long, belongs to Hypsibius dujardini, one of about 1,100 tardigrade varieties known to exist. Also called water bears or moss piglets, tardigrades can be revived after exposure to temperatures as low as minus 458 degrees Fahrenheit and the vacuum of open space.…

A RESEARCHER INVESTIGATING HOW the stress levels of people in non-industrialized societies differ from those of modern Americans found himself in a different kind of stressful situation when he came face-to-face with a killer. Biological anthropologist Samuel Urlacher left the urban jungle of Boston, where he was a graduate student at Harvard University, for the actual jungle of Papua New Guinea. Since 2013, he’s worked among the Garisakang, an isolated clan of about 500 foragers and garden-scale farmers living in tropical villages without electricity or running water. Urlacher, now a postdoctoral fellow at Hunter College in New York, has collected more than 1,600 saliva samples in order to measure the stress hormone cortisol. But sometimes, fieldwork has its surprises. Like the day Urlacher crossed paths with a cassowary, one of…

Six thousand, five hundred and twenty-one days: That’s how long I’d been living with my son when he left home for college. I’d spooned applesauce into his gummy mouth when he was a baby. I’d watched him wobble down the street on training wheels when he was a preschooler. I’d learned to rise on tiptoes to kiss his stubbled cheek when he was a teenager. For nearly 18 years, I’d been there for the big moments and the daily nothings. I’d fretted about him and had fun with him. While he wasn’t my only focus in life, he took up a big front-and-center chunk. We knew well in advance he’d be leaving. My husband and I live in a small town. With aspirations to attend college, our son had no…

Humans have altered their food for thousands of years. 10,000 B.C. FIRST FARMERS: Humans begin domesticating plants for food. EARLY 1900s PLANT BREEDING BECOMES SCIENCE: Sir Rowland Biffen crosses breeds to create disease-resistant wheat. Scientists can now select for traits instead of relying just on chance. 1994 FIRST COMMERCIAL GMO: Calgene (today owned by Monsanto) launches slow-ripening Flavr Savr tomatoes. It’s a hit with consumers, but soon is canceled in part due to high costs. 1999 OPPOSITION GROWS: A Cornell University study implies GMO corn pollen endangers monarch butterflies. Experiments by the USDA rebut the finding, but the perception sticks. 2003 FRESH REGS: The European Union passes strict rules on GMOs. Many EU countries later ban farming them. 2012 NEW EDITS: Scientists show they can edit genes with CRISPR, and…

1 Materials selection The first step to making a functional fiber is to choose the right materials. Depending on what the fabric will do, these materials may include insulators, semiconductors and metals — the basic ingredients of optics and electronics. All of these must melt at the same temperature so they can be combined and drawn together. 2 Creating preform To perform a task, such as lighting up or measuring vibrations, the fiber’s components need to be organized very specifically. First, you make a “preform” by rolling materials into tubes and nesting them in layers. The core of the preform may be a solid rod made out of one of the materials, or may be hollow to accommodate the flow of liquids through the final product. After assembling the preform,…

1 Diamond, a particular form, or allotrope, of carbon, is the hardest material we know of. It’s more than twice as hard as the closest competition, silicon nitride and cubic boron nitride. 2 That extraordinary hardness arises from a strong and inflexible structure: Five atoms form a tetrahedron and share electron pairs with each other. 3 In nature, diamond is typically created under extremes of pressure and temperature, deep in Earth’s mantle — about 90 miles or more beneath our planet’s surface. 4 Except for space diamonds, of course. In 2017, researchers re-created, for the first time, the conditions under which they believe diamond rain forms in Uranus and Neptune. 5 These planets have internal temperatures just right for diamond formation. As hydrocarbon gases sink toward their cores, increasing pressure…

MORE THAN A DECADE AGO, Discover reported on an $85 million project to restore what was formerly one of the world’s biggest inland bodies of water: the Aral Sea. An oasis on the Silk Road trading route, the sea once covered more than 26,000 square miles across the heart of Central Asia, including parts of Kazakhstan and Uzbekistan. This all changed in the 1950s, when a Soviet irrigation project diverted river water to rice and cotton fields miles away. The system leaked, and the sea began to dry up. By the 1990s, the Aral had shrunk to less than half its former size and was dangerously salty. It was no longer one body of water, but two lobes: a smaller North Aral Sea in Kazakhstan and a larger South Aral Sea…

Doctors Wined and Dined Ever wonder how drug marketing plays into what your doctor prescribes? A team of researchers found that D.C.-based health care providers who got gifts — including cash, meals and ownership interests — from pharmaceutical companies prescribed more drugs per patient, wrote more expensive prescriptions and were more likely to recommend brand names. And the pricier the swag, the more likely doctors were to do these things. Building Blocks Incredible, Edible Corn Just because E. coli has a bad reputation doesn’t mean it’s not useful. Experts at Rutgers University-New Brunswick in New Jersey have found a way to boost corn’s nutritional value by inserting a gene from the bacterium. The key was getting the grain to naturally produce enough methionine, an amino acid essential for an animal’s…

Smeared on shells, piled in graves, stamped and stenciled on cave walls from South Africa to Australia, Germany to Peru, ochre has been a part of the human story since our very start — and perhaps even earlier. For decades, researchers believed the iron-rich rocks used as pigment at prehistoric sites had symbolic value. But as archaeologists turn up evidence of functional uses for the material, they’re realizing early humans’ relationship with ochre is more complex. Tammy Hodgskiss, an archaeologist at the University of Witwatersrand in South Africa, has studied sites in that country such as Rose Cottage Cave, where evidence of ochre use spans more than 60,000 years. “People may say ochre is the earliest form of art and symbolism, but there’s more to it,” she says. “Ochre shows…

OTHER NAMES: Huanglongbing (HLB), yellow dragon disease. CAUSED BY: Candidatus Liberibacter asiaticus bacteria, spread by the Asian citrus psyllid insect. AFFECTED: Citrus plants, including oranges, grapefruits, lemons, limes and tangerines. SYMPTOMS: Yellow shoots; dark aborted seeds; mottled or patchy discoloration to leaves; mature fruit that is small, hard, misshapen, partially green and falls from its stem prematurely; bitter taste. CURE: None. Infected trees usually die within a few years.…

In February 2008, 53-year-old Carol Vincent found a strange swelling on her body. Having just recovered from a bout of illness, she dismissed it as the last flutterings of the flu. Her fiancé persuaded her to consult her doctor, which she did, almost breezily, assuming he would tell her that the enlarged knuckle-like node was of no real concern. Instead, as her doctor pressed and palpated, a shadow passed over his face, and fear took hold in Vincent. The next thing she knew she was being X-rayed and biopsied. Later, dressed and seated in her physician’s office, Vincent was informed she had lymphoma, a kind of cancer for which there is no cure and no consistently effective treatment, either. As days and weeks went by, the strange swelling migrated and…