DiscoverMay 2014的目錄

I don’t have a lot in common with Franklin Chang Díaz — physicist, onetime astronaut and designer of the prototype rocket that could take humankind to Mars (and beyond). Compared to this man, I feel like something of an underachiever. But in reading our cover story (“Rocket Man,” page 36) for the frst time, I did feel a moment of brotherhood when I learned that Chang Díaz’s fascination with space began in childhood, after the launch of the frst Sputnik satellite in 1957. Sputnik was a little before my time, but I felt a similar childhood obsession with space exploration, sparked by seeing the frst pictures from Mars during the 1976 Viking mission. I remember those images clearly — although I have no recollection of other results reported from Mars…

Valley fever, a potentially fatal dust-borne infection caused by a soil-dwelling fungus, has lurked in the deserts of the Southwest United States for hundreds of years, if not longer. But in the past decade, the disease has seen an uptick in cases, leading to a “silent epidemic,” according to the Centers for Disease Control and Prevention. Because of increasing development in arid climates where the fungus lives, as well as better testing and diagnosis, the infection’s incidence has skyrocketed, reaching 22,500 cases in 2011, up from 2,265 in 1998. But with many cases going unreported, experts believe as many as 150,000 people may be sickened annually. Medically known as coccidioidomycosis, or cocci for short, the lung infection is caused by a fungus in the mushroom family that begins life as…

Q: Can you tell me why a spiral design seems omnipresent in our natural world and in the universe? I see this pattern in plant tendrils, flowers and leaves, pinecones, the unfurling of needles, as well as in astronomy. — Dorothea Fox Jakob, Toronto A: The short answer is, sadly, we don’t really know. Nature does seem to have quite the affnity for spirals, though. In hurricanes and galaxies, the body rotation spawns spiral shapes: When the center turns faster than the periphery, waves within these phenomena get spun around into spirals. The forets in a sunfower head also form two spirals, but there’s no rotation here — it’s simply an effcient packing solution for the plant. With 55 forets running clockwise and 34 counterclockwise, the sunfower is an example…

The brain of a person seizing sounds to some like atonal and eerie avant-garde music. To others it’s more like a band of coyotes yipping and barking with a crescendo of howls. Of course, the brain itself isn’t making the sounds at all; they’re the product of a new invention that converts brain waves into a vivid audio portrait, providing instant insight into the goings-on inside a person’s head. The device, called a brain stethoscope, was designed to help recognize and detect types of seizures that — unlike the generalized “grand mal” seizures that leave victims convulsing — present themselves subtly. Some temporal lobe seizures, for example, may cause patients to look absently into the distance and smack their lips. Seizures can disable memory and language, so it can be…

Long before modern refrigeration, people in Russia and Finland reportedly placed living Russian brown frogs in milk to keep it fresh. It turns out the curious practice has a basis in science: Recent research on the amphibians’ skin secretions led by Moscow State University organic chemist A.T. Lebedev shows they’re loaded with peptides, antimicrobial compounds as potent against Salmonella and Staphylococcus bacteria as prescription antibiotics. To your health! Ƭ JENNIFER ABBASI…

More than 9 billion people will live on Earth by 2050. They’ll need to eat somehow, but we’re already running out of arable land. And many types of agriculture — including conventional farming of annual crops, which need to be replanted each year — leave fields nutrient-poor, reducing future productivity. But soil scientist Jerry Glover is optimistic about feeding more people while conserving farmland soil. The solution, he believes, is to focus less on annual crops, which dominate world agriculture, and to embrace instead the potential of perennials, crops that can be harvested more than once without replanting. Glover, a senior sustainable agricultural systems research adviser at the U.S. Agency for International Development (USAID), spent years as a researcher at the Land Institute in Kansas. There he realized the state’s…

Beginning on Oct. 29, 2012, the sea paid a little visit to New York. In the space of just a few hours, Hurricane Sandy threw history into reverse, sabotaging several hundred years’ worth of hard-won and fabulously expensive reclamation. An hour southeast of Manhattan, Jones Beach, a onceswampy strip of barrier island raised 10 feet by urban planner Robert Moses in the ’20s, took a terrible beating. Crashing waves reduced the wooden boardwalk to splinters. Lifeguard shacks were tossed around like toys. Metal highway signs snapped, underpasses flooded. The storm left such a powerful statement in its wake that even Donald Trump sat up and took notice. Hurricane Sandy put the kibosh on his plan for 86,000 square feet of development on the beach. Trump on the Ocean became Trump…

Ah, summer. Sunshine, warm temps and long days — three things that don’t matter when you’re sitting in a multiplex, ready for Hollywood’s biggest season and most effectsdrenched movies. But it can be tough to figure out which time-traveling, mind-bending, edge-of-Armageddon epic you’ll enjoy most just judging by the trailers, which have a confusing degree of sameness. Have no fear. If you’re stumped on which movie is worth your time, just go with the flow — or at least our flowchart. Ƭ GEMMA TARLACH…

INFINITESIMAL By Amir Alexander The principle of "infinitesimals" — the possibly infinite, hypothetical, indivisible points that populate a geometric line — underlies calculus and much of our modern technology, from airplanes to computers. But back in the 17th century, the unorthodox idea, which dared to suggest the universe was an imperfect place full of mathematical paradoxes, was considered dangerous and even heretical. UCLA science historian Alexander puts readers in the middle of European intellectuals’ public and widespread battles over the theory, filling the book’s pages with both formulas and juicy character development. Ƭ BILL ANDREWS A WINDOW ON ETERNITY By Edward O. Wilson Mozambique’s Gorongosa Mountain means “place of danger”— fitting for a remote rainforest that saw its biodiversity bulldozed during 15 years of civil war late last century. A…

Reef Environmental Education Foundation Key Largo, Fla. 25°5’11.45"N, 80°26’50.2"W www.reef.org/trips The indigo waters off Key Largo are teeming with biodiversity, but overfishing, pollution and climate change are taking their toll. You can strap on scuba gear and help researchers monitor more than 400 fish species affected by human activity by joining REEF in a weeklong diving survey. DIVE INTO THE BLUE: REEF surveys show the goliath grouper (Epinephelus itajara) is making a comeback thanks to international and federal protections. Because the fish can grow to 800 pounds, it takes a long time to reach reproductive maturity. By 1990, after decades of overfishing, the slow-growing grouper had nearly disappeared from local waters. It was listed as critically endangered in 1994 by the International Union for Conservation of Nature. Now, however, while…

Boulder, Colo. 39º58’41.34"N, 105º16’29.71"W www.spark.ucar.edu/visit Nestled against the foothills of the Rocky Mountains, the National Center for Atmospheric Research (NCAR) studies weather, climate and atmospheric science. At its Mesa Laboratory and Visitor Center, guests can touch a cloud, make a tornado and even steer a hurricane. LIVE AND LEARN: NCAR scientists have been conducting research on Colorado’s recent megaflood to improve future forecasting. TOUR IT: The Mesa Lab is open 8 a.m. to 5 p.m. on weekdays and 9 a.m. to 4 p.m. on weekends, 363 days a year. Employee-led tours are available at noon Mondays, Wednesdays and Fridays; selfguided audio and tablet tours are offered throughout the day. All tours are free. WEATHER WALK: Take a short walk along NCAR’s roughly half-mile Weather Trail, where interpretive signs describe phenomena…

1 Think of the term alligator skin as a compliment: It’s extraordinarily sensitive to minute changes in vibration, which helps locate prey. 2 Alligators are touchy, but the platypus is more the feely type. The only mammal with electroreception, it uses sensors in its bill to detect electrical impulses sent out by prey in murky water. 3 Researchers believe electromagnetism may help red wood ants sense imminent earthquakes in time to evacuate their mounds. Someday these creatures may be part of geologic threat-detection systems. 4 Elephants, too, are acutely aware of vibrations. They use seismic activity generated by their trunks and feet to communicate with one another about predators, territory and mating preferences. 5 Star-nosed moles have 22 tiny trunks containing a total of nearly 100,000 nerve fibers — six…

Mars: Worth the Risk? The top story of 2013 in our Year in Science issue, Curiosity’s search for evidence of life on Mars, discussed the drawbacks of manned spaceflight to the Red Planet. You say that the yearlong round trip to Mars will increase an astronaut’s lifetime cancer risk as much as 3 percent. Remember the scene in Butch Cassidy and the Sundance Kid where they have to jump off the ledge into the river far below? Sundance says he can’t swim, and Butch replies, “Are you crazy? The fall will probably kill you!” Let’s work on ameliorating the real risks involved in getting to Mars frst and worry about the picayune ones later. By the way, where do I sign up? I’m ready to leave tomorrow. I’ve been ready…

The cocci fungus flourishes in southwestern regions with dry weather and sandy soils, such as Arizona, Utah, New Mexico, parts of Texas and California’s San Joaquin Valley, which gave valley fever its name after a major outbreak there in 1930. Any disturbance in the soil — construction, oil exploration, archaeological digs, earthquakes or high winds — can stir up a cloud of spores. However, no one is sure which environments the fungus favors. A site may become more or less hospitable to the spores as temperatures, moisture levels and soil ecology change. Hoping to pinpoint the areas with fungus-friendly soils so residents can take extra precautions, physicists and geologists at California State University, Bakersfield, led by physicist Jorge Talamantes Rivera, are using satellite images to match features between sites where…

Mark Hoddle knows how to fight biology with biology. As director of the Center for Invasive Species Research at the University of California, Riverside, he has overseen some of the most effective methods ever documented for suppressing invasive pests with their natural enemies. Scientists and government officials sought his help in French Polynesia, where islands were overrun with the glassy-winged sharpshooter, or Homalodisca vitripennis. First detected in Tahiti, the halfinch-long, mottled brown leafhopper carries a plant disease-causing bacterium, and the insect had spread to other islands in French Polynesia. It was wreaking havoc on native crops and vegetation in addition to swarming people, encrusting streetlights and invading buildings by the hundreds. Because the sharpshooters extract a waterconducting plant tissue called xylem and excrete it at 100 times their body weight,…

When environmental engineer David Cwiertny began analyzing the fate of an agricultural chemical called trenbolone acetate in streams across the United States, he and his colleagues stumbled into a B-grade horror film starring a vampire steroid. Beef cattle producers across the U.S. rely on trenbolone acetate to bulk up their animals. During digestion, the steroid breaks down into metabolites, which cattle excrete in urine and manure. Early studies showed that these metabolites degrade quickly in sunlight, leaving only their chemical building blocks in feedlot runoff. So while exposure to trenbolone metabolites is known to interfere with normal hormone functions in lab animals, the sun-degraded steroid was believed to have a small and short-lived environmental footprint. The FDA gave its stamp of approval to this synthetic testosterone in 1987, and it…

When I met Judy, I had just finished seeing what seemed like 100 diabetic patients, one after the other. As an endocrinologist, I specialize in the management of hormonal disorders, and this is business as usual for me: More than 60 percent of my patient visits focus on diabetes. I picked up my last chart of the morning and saw that it was another new patient with Type 2 diabetes. Judy was 47 years old, and as a result of her illness, she already had suffered several heart attacks and developed eye and kidney damage. She also had blockages in the major arteries that supply her legs with blood, and she had dangerously high blood pressure. I flipped through Judy’s chart, noting no other unusual medical problems. Although she clearly…

TRAVELING TO MARS IS NOT EASY, which may be why no one has ever tried. It would take a good six to nine months to get there with today’s chemicalfueled rockets. Along the way, according to a 2013 study, you’d get dosed with the radiation equivalent of a whole-body CT scan every five to six days, increasing your lifetime cancer risk above the limits set by NASA. Upon reaching the Red Planet, you’d wait up to two years for Earth and Mars to be at their closest before your return trip, which would last another six to nine months. If the cosmic rays didn’t get you, the long layover might. But what if there were a better way — a new kind of rocket that could transport you to Mars…

In the movies, first contact with aliens unfolds with great drama. Often, extraterrestrials arrive with laser guns blazing; in more benevolent scenarios, they show up in the form of hooded Vulcans, glowing-fingered empaths or black-box artifacts buried on the moon. Regardless, the main message is clear: We are not alone in the universe. In reality, the discovery of alien life will come with a lot of ambiguity and skepticism. How can I be so certain? Because it has already happened. Twice. In 1976, the twin Viking 1 and Viking 2 landers touched down on Mars and initiated the most ambitious effort ever undertaken to seek life on another world. The robots scooped up soil and ran four experiments. In one of them, a sample was incubated in a nutrient broth.…

The excavated terra cotta army of life-size soldiers, horses and chariots buried with the First Emperor of China some 23 centuries ago is an impressive sight now — but just imagine how the 8,000-plus figures looked when new, covered in brightly colored paints. This kid-friendly exhibit of more than 100 artifacts from the army, including several figures, focuses on how the paints were made and how they can be preserved. It’s the only stateside appearance of the famous terra cotta warriors in 2014, according to organizers. Opens May 10. childrensmuseum.org Ƭ GEMMA TARLACH…

Researchers are buzzing with concern over declining bee populations due to habitat loss, pesticide use and other factors, but systematically tracking the insects has been challenging. An online project launched earlier this year aims to create a network of monitors across the U.S. and Canada to get a better idea of where bumblebees are thriving — and where they’re not. All a pro-pollinator needs to join the project is a smartphone or digital camera and an Internet connection. Ƭ GEMMA TARLACH LEARN MORE BUMBLE BEE WATCH Be part of a new network Take pics of bees because bees can’t take selfies. BumbleBeeWatch.org…

Richland, Wash. 46º38’51"N, 119º35’55"W www.hanford.gov The Hanford Nuclear Reservation, a onetime national secret, now hosts both a National Historic Landmark with free, guided tours and a $40 billion environmental cleanup. Part of the Manhattan Project, this site in southeastern Washington produced plutonium for atomic bombs during World War II and the Cold War. TO B OR NOT TO B: Choose between two half-day tours: an in-depth exploration of the deactivated B Reactor, the world’s first full-scale plutonium production reactor; or a sitewide bus tour through Hanford’s history, from its top-secret wartime construction to the U.S. Department of Energy’s present-day cleanup operations. BOOK IT: Tours run April through September and fill up fast, but don’t worry: Occasional cancellations mean empty seats are sometimes up for grabs. GOOD TO KNOW: Tours start…

5/4 Star Wars Day Say it with us: “May the fourth be with you!” starwars.com/news/the-history-of-may-the-4th.html 5/8 Mega-Bad Movie How good — or bad or ugly — is the science in 1998’s notorious bomb Godzilla? Experts provide commentary during a screening at the Academy of Natural Sciences in Philadelphia. ansp.org 5/10 Anniversary Party Utah’s Golden Spike National Historic Site commemorates the 145th anniversary of the completion of the Transcontinental Railroad, one of the earliest examples of a staged media spectacle, with reenactments, ceremonies and live music. nps.gov/gosp 5/17–5/18 Museums Rock Around the Clock During the European Night of Museums, many institutions across the Atlantic postpone their closing times to the early morning hours, often with free admission. tinyurl.com/EuroNightMuseums 5/25 Big Night for the Littlest Planet Mercury reaches its greatest eastern elongation…

This baleen whale was one of dozens stranded belly-up 6 million to 9 million years ago in a desert in modernday Chile. A road construction crew uncovered the boneyard in 2010. Paleontologists had two months to dig and digitize fossils with 3-D scanners before Cerro Ballena, or Whale Hill, was buried beneath a new northbound lane. This year, scientists deduced the mammals’ likely cause of death: ingesting or inhaling toxic algae. — ERNIE MASTROIANNI;…

It’s not easy to hide if you live in the open ocean. To avoid predators, some fsh sport pale bellies and dark backs to blend in with the sky and the deep. Others are transparent. But evolutionary biologists at the University of Texas have discovered a true undersea camoufage expert: a fsh that manipulates polarized light. Humans generally can’t perceive light polarization, the parallel alignment of light waves, but many fsh can. So can their predators. Curious if prey species have evolved ways to exploit that ability, the researchers caught some lookdowns — a silvery game fsh often found in public aquariums — in the Gulf of Mexico. Placing the fsh in a tank, they shined artifcial sunlight onto the water at different angles to represent the light at various…

Astronomer Tycho Brahe knew the position of nearly every star in the sky. But strolling home one November night in 1572, he saw a strange new light. The stella nova, modern astronomers now know, was actually a supernova. After 450 years, its remnant has faded like a firework and no longer glows visibly. Thanks to a secret energy source, though, it still shines in X-rays nearly as bright as it did in its youth. When a massive star explodes, the spray of stardust collides with interstellar gas, forming an outgoing shock wave. The wave heats its surroundings billions of degrees, leaving a blazingly bright wake. Within months, the lowenergy visible light dims as the plasma spreads and cools. The high-energy X-rays should peter out, too. But, as what’s now called…

Life isn’t easy when you set down roots in a harsh environment. Among the plants that make a go of it are Lithops, more commonly known as living stones, a type of succulent that thrives in the superhot, superdry conditions of southern Africa. How do they survive? A study by University of Cambridge botanist Matthew Davey and colleagues suggests it’s the plant’s clever engineering. Living stones, named for their rocky appearance, bury the bulk of their leaves underground, taking a dive for shade. They use specialized structures to channel light to the buried parts. The aboveground plant cells have adapted to the bright, dry conditions with a sunscreen-like pigment and a special blend of chlorophyll that allow them to photosynthesize without frying to a crisp. The underground cells are coneshaped…

Imagine lying inside a massive functional magnetic resonance imaging (fMRI) machine, your head surrounded by a 10-foot-wide white magnetic doughnut. While you lie there, daydreaming, the scientists in the room next door monitor the patterns of activity that flicker around in your brain. Then someone sneaks up and stabs your hand with a fork. Nerve signals shoot up your spine, then radiate all over your brain: Ouch! The scientists in the next room didn’t see what happened. But since they’re looking at images of your brain on a monitor, it seems like there is no way they would miss what you just felt. Such an intense sensation must light up the fMRI scan like a Christmas tree, right? Nope. In fact, your feeling of pain is impossible for them to…

MENNA JONES PEERED into a trap, and a Tasmanian devil peered back at her. Its gaze was somehow off. The devil’s face seemed misshapen, and its jaw was raw and red. Perhaps, she thought, the swelling was an infected wound. Many devils are torn up by the end of the breeding season, after a month of winning and defending mates. Jones, a biologist at the University of Tasmania, was trying to decipher the social structure of the island’s iconic creature, the largest meateating marsupial in existence. Were the devils promiscuous, as many researchers suspected? Which ones were studly and prolific, and which ones were losing the reproductive race? This fellow was one of many helping Jones answer those questions in June 2001 at her study site on the Freycinet Peninsula,…

Just east of Yellowstone National Park, snowcapped mountains rise sharply on either side of the narrow road to Cody, Wyo. This lush valley gets its name, Wapiti, from the Shawnee and Cree word for elk. Herds of these majestic animals spend sunny days grazing the basin’s greenery and drinking from the glinting waters of the Shoshone River. Teddy Roosevelt called this stretch of Wyoming’s North Fork Highway “the most scenic 50 miles in the world.” “Not so much in the winter,” says Arthur Middleton, a biologist who has logged hundreds of hours in the blistering cold north of the Wapiti Valley in recent years, trying to explain the region’s mysterious elk decline. His team fits the swift and unwieldy beasts with GPS collars to track their movements in the vast…

An estimated 10 million Americans have essential tremor, a rhythmic trembling in their hands that intensifies with action — and can turn mealtimes into spoon-vs.-mouth target practice. Enter Liftware, a battery-powered spoon that stays steady despite the user’s shaking. Discover’s Elisa Neckar spoke to LiftLabs’ founder Anupam Pathak about the technology that’s leaving tremor sufferers “blown away by being able to eat rice and peas for the first time in years.” Bon appétit! Taking Aim at Tremor As a doctoral student, Pathak researched countermeasures for physiological tremor, the normal shake present in everyone’s hands that can intensify with an adrenaline surge, low blood sugar or exhaustion. Physiological tremor can be a big problem in certain situations, such as combat, and Pathak’s work (funded by the U.S. Army Research Laboratories) focused…

D-DAY’S SUNKEN SECRETS PBS, 9 p.m. EDT May 28 Whether from history books, movies such as Saving Private Ryan or firsthand accounts, most of us can picture how the 1944 Allied invasion of Normandy unfolded — on the surface, that is. But understanding what happened below the waves of the English Channel is, as the new Nova episode explains, "like investigating a crime scene spread out over 300 miles and buried under 120 feet of water." A team of marine archaeologists and other researchers use cuttingedge technology to scour the underwater battlefield, identifying shipwrecks and reconstructing some of the lesser-known events of the largest naval invasion in history. The richly detailed two-hour program also reveals impressive engineering feats that made D-Day possible, from floating tanks to man-made harbors that could…

Mount Desert Island, Maine 44º20’34.18"N, 68º18’25.7"W mountdesertisland.net Maine’s largest island, Mount Desert, is an oasis of vacation activity options. Tour a world-renowned laboratory; hike through Acadia, the first national park in the Eastern U.S.; and take a boat trip to see the “island of barren mountains” from the water, as French explorer Samuel de Champlain first did. MOUSE TALES: Summer tours for visitors ages 12 and up are available for The Jackson Laboratory, a pioneering cancer genetics research institute. The facility is home to the world’s first online genetic database, the Mouse Genome Database, used by biomedical scientists worldwide. Tours run about an hour and are by appointment only. Visit www.jax.org/about/tours.html for details. TOUR DE ILE: Explore Acadia National Park by bike. Many of the park’s main attractions can be…

May’s early evening sky harbors a trio of bright planets. Shortly after night falls, you’ll find Jupiter gleaming low in the west and Mars riding high in the south. Both objects shine noticeably brighter than any star (at least after Sirius sets during twilight). It takes only a bit more effort to spot Saturn, which stands out this month in part because on May 10 it reaches opposition, the point in its orbit where a planet lies opposite the sun in our sky. This means Saturn rises at sunset and remains visible all night. Opposition also marks the planet’s closest approach to Earth, so it shines brighter (magnitude 0.1) than at any other time of year. While the naked-eye view impresses, don’t pass on an opportunity to observe Saturn through…