DiscoverSeptember 2014的目錄

Mystery Stories This time last year, the Discover team was as busy as it has ever been. We were just putting the finishing touches on a redesign of the magazine, always a chaotic and time-consuming point in the life cycle of any publication. While we introduced many new elements with that frst new issue, quite a few old, cluttersome items departed from Discover for good. Our Vital Signs column, which invites readers to follow along with a doctor as he or she strives to solve an unusual medical case, was not one of those permanent deletions. Readers could be forgiven for thinking it was, though: Due to various editorial concerns that I won’t belabor, we had to cut two pages from the magazine at the last minute, so we pulled…

The world’s reef systems face unprecedented stresses, under threat from over fishing, pollution and climate change. Most threatened is the Caribbean reef system, with more than 80 percent of its live coral cover disappearing since the 1970s, largely due to global warming. A visual example of this toll is called coral bleaching, which turns the animals a ghostly white — the result of warmer waters expelling the algae that give coral its color and sustenance. An innovative project in southern Belize is working to turn the tide not just by rebuilding reef systems, but also by learning from natural heat-resistant corals. The research was inspired by a serendipitous discovery after Hurricane Iris tore through Central America in 2001. The storm demolished large swaths of the Belize Barrier Reef system, part…

A All matter is composed of the chemical elements on the periodic table — even the supposedly man-made ones. In nature, the most common heavy element is uranium. It has 92 protons in its nucleus. The 26 heavier elements we know of so far, going up to 118 protons, were synthesized in nuclear reactors or particle accelerators, effectively created from the pieces and energy of other elements. Scientists pursue these new superheavy elements to better understand the limits of matter. But nature is just as capable of making these “fundamental substances,” too. For example, researchers created plutonium (94 protons) in a lab in 1940 and ’41. The element later turned up in uranium ore deposits, where natural radioactivity can produce traces of plutonium. Alternatively, supernovae — the explosions of massive…

Carolyn Kroot was an energetic and ambitious National Guard member when she was deployed to the Persian Gulf in 1990 and 1991. Serving in a maintenance unit in the six-week campaign to drive Iraq out of Kuwait, she was never on the front lines and suffered no physical injuries. But when she returned home to Maine, she felt exhausted all the time. She started getting severe migraines, and she struggled to focus, to the point where she asked to forgo promotions. “Every day was a struggle,” she says. “It was very scary and disappointing.” She was only 33. Like many other Gulf War veterans with similar symptoms, Kroot was told her problems were due to mental stress and best treated with an antidepressant. She was sure it was more than…

yogi Berra was right when he said, “The future ain’t what it used to be.” Only he wasn’t right in the way he meant it, which was usually the case. The future really isn’t what it used to be — it’s much, much brighter. Consider the extraordinary time you live in: There has never been a period in history of such rapid advances in medical knowledge and technology. Now consider the even more extraordinary time you will live in: The following cures of the future are sinking their roots in the now. Forget Sherlock; It’s All About Watson Watson is the real stickler for data, data, data — but not the Arthur Conan Doyle character. Instead, it’s the IBM supercomputer getting buzz for such flashy feats as winning rounds on…

A telescope as big as the world will give astronomers an extreme close-up when our galaxy’s black hole lights up. The giant black hole in the middle of our galaxy stays pretty quiet most of the time, faring up only occasionally. But it is due for a burst of activity any day now, as a large cloud of gas and dust continues to spiral toward the heart of the Milky Way. With this sudden infux of material, the normally tranquil black hole — named Sagittarius A* (pronounced “A star”) and as massive as 4 million suns — will roar to life, unleashing a fiery discharge of matter and radiation. The cloud, dubbed G2, is expected to make its closest approach this year, although it could take decades for the black…

A dozen years ago, Daniel Doak began crawling around the Alaskan tundra carrying a container of colorful party toothpicks. He was there on the chilly North Slope at the top of the continent to study moss campion, a low, fat plant that explodes with pink flowers in early summer. Moss campion seedlings are “the size of the head of a pushpin,” Doak says, and 20 years can pass before they grow much bigger. Nonetheless, Doak, an ecologist at the University of Colorado, dutifully identified, mapped and measured the plants, using the toothpicks to mark the location of the smallest ones. Every summer he returns, and after all those years of strained eyes and bruised knees, he now has data on 2,500 plants in the Arctic and thousands more at sites…

Curiosity has already wowed us with a series of splashy discoveries since its complex landing on Mars in 2012. But the rover’s biggest achievement may be yet to come. At press time, Curiosity was closing in on its target destination: 18,000-foot Mount Sharp in Gale Crater. Marc Kaufman, author of the new book Mars Up Close: Inside the Curiosity Mission, talked to Discover about what the rover and the scientists behind it have already achieved, and the tantalizing possibilities ahead. Q What has impressed you most about Curiosity’s time on Mars so far? A The stuff they’ve been finding has been astounding. They’ve not only made the determination that the area was habitable, but also that it’s not that different from other areas of Mars. We’ve always called Mars the…

Shine on Harvest Moon Sky gazers typically view the full moon with disdain. Its bright illumination makes stars and planets appear less conspicuous to naked-eye observers, and washes out delicate details in deep-sky objects for those peering through telescopes. But this month’s full moon, which arrives precisely at 9:38 p.m. EDT on Sept. 8, has a special charm. As the full moon closest to the Sept. 22 autumnal equinox, it also goes by the more poetic name “harvest moon.” Oddly enough, what distinguishes it from other full moons is what happens several evenings before and after. Every night, the moon generally rises about 50 minutes later than it did the previous night. Blame it on the ecliptic, the arc of the sun across the sky, which the moon follows closely.…

Cross Contamination Corey Powell’s May “Out There” column discussed the search for alien life. “Why is E.T. MIA?” suggests sending a probe to “simply” take a few passes through the ejecting plume of a moon of Saturn and bring back samples to Earth labs to look for alien life. What if the sample contains a pathogen that wiped out life on Saturn? Exposure to such things is a high price to pay to satisfy curiosity. Laurie Goffman Palm Desert, CA Author and editor at large Corey Powell responds: That’s a very valid concern. Fortunately, it is one that people at NASA have thought about extensively; in fact, NASA has a whole office devoted to the issue of “planetary protection” from contamination. The office establishes rules both to make sure we…

Jason Drew’s farm doesn’t include artisanal arugula or free-range livestock. His South African company, AgriProtein, grows flies. The pests have the same amino acids as more expensive commercial fish meal, making them an attractive protein source for poultry and fish farmers. After the fly eggs hatch, the larvae feast on waste: leftovers from human food production like juice pulp, and slaughterhouse scraps like pork blood. Some of the larvae are then harvested, dried and pressed into different shapes as food for various seafood and poultry species. The larvae that escaped the food mill grow up and continue the cycle, laying eggs. Two new factories in South Africa will each soon house 8.5 million flies, and have a daily output of 30 tons of pressed larvae — fly farming on an…

“They’re just rocks floating out in space. So what?” says UCLA astrophysicist David Jewitt. That’s how he used to feel about asteroids. The common wisdom holds that asteroids live placid lives before meeting a predictable, standard death: A pair collide, quickly obliterating each other. But recently, scientists have spotted asteroids behaving and dying in unexpected ways: Some have tails, some break apart into chunks and others disintegrate into smears of dust, with no obvious second asteroid in sight. What the heck? Jewitt has his theories for these space oddities. Some of it is sublimation: an icy asteroid transforming directly into water vapor as it makes its way toward the sun. Rocky asteroids, however, are more complicated. In August 2013, he found an asteroid with six tails — a never-before-seen configuration…

→He was dead. His face a terrifying, sweat-slicked white, the young man’s body lolled lifelessly on the emergency room gurney Five hours earlier, Marty had walked in a strong, healthy 27-year-old. His only worry: some sharp pains in the left side of his chest that started two days earlier. He fgured it might be a muscle pull from weightlifting. But then it spread. “Any shortness of breath?” I asked. “No.” “Pain down your arm?” “Just the chest.” “Do you smoke?” “Half a pack.” “Cough? Fever lately?” “No, doctor.” Marty was young for heart disease, but he was a smoker, I reminded myself. “OK. Let’s take a listen.” With his shirt off, Marty’s compact frame bulged. On the left side, the sound of his breathing came through only faintly. Too much…

i know the moment it started. Seven years ago, my mother and I were strolling — not briskly — by my hospital. As we chatted, it hit me that something was amiss. “Mom, are you OK?” I asked. “I’m fne, why?” she replied, her chest heaving. “Are you out of breath?” “Oh, I’m just out of shape.” She smiled and batted her right hand to wave me off. At 71, my mother is an expert denier, but she has had her share of serious medical issues, including lupus — an autoimmune disease that can target almost every organ — and a stroke that rendered her left arm nearly useless. An accomplished piano teacher, she still managed to resume teaching. She never met a symptom she wouldn’t rather ignore. “You’re out…

By Col. Robert Hale’s count, Todd Nelson had already cheated death twice when he arrived at Brooke Army Medical Center in San Antonio. A 34-year-old senior logistics supervisor based in Kabul in Afghanistan, Staff Sgt. Nelson had escaped injury on hundreds of convoys by relying on speed, agility and a little luck. On a hot August day in 2007, a month before he was due to go home, his luck ran out. Nelson and his partner, Chris Sanders, were headed back to camp when a Toyota Corolla pulled in front of their truck. Sanders hit the brakes and swerved to the left, then locked eyes with the car’s driver, who flipped a switch, blowing his car, and himself, to bits. Sanders, shielded by Nelson, escaped with minor burns. Nelson took…

Examining the worries and “what ifs?” that fuel vaccination fears, University of Michigan researcher Brian Zikmund-Fisher looks calmly at the camera in the documentary “Vaccines — Calling the Shots” and says: “Is it OK to question? Of course it is.” An American update of the 2013 Australian documentary “Jabbed — Love, Fear and Vaccines,” “Calling the Shots” strips away the drama, misinformation and namecalling that mire serious discussion of what has become a public health crisis in the developed world: About 10 percent of parents in the U.S. alone choose to skip or delay recommended vaccinations for their children, and 1 percent don’t vaccinate at all. “Calling the Shots” executive producer Michael Rosenfeld and writer/producer/director Sonya Pemberton, who was also behind the original Australian version, discussed with Discover Senior Associate…

Q Just “a good chance?” AAdam Steltzner, who developed Curiosity’s Skycrane and is an engineering rock star, told me that in terms of designing a capsule large enough for humans and getting it onto Mars, the technology is totally feasible. The issue is whether there is the determination to pay for it. QWhat’s your 30-second pitch for why we should go? AThe answer can’t be just “for the science,” because most of the science can be done from Earth. It has to be to make a grand statement about what humans can achieve — that’s something we do well, and it inspires people to go into the fields we need them in. — GEMMA TARLACH SHOCKED Thanks to advances in medicine, there’s dead and then there’s really dead. Physician and…

BY GEMMA TARLACH 1 Your kitty’s ancestor was a solitary hunter of small prey, as opposed to dogs’ ancestors, which were large-game pack hunters. That’s why Rover tends to gulp down a big meal while Mittens prefers to eat several smaller meals throughout the day 2 Cats will hunt even if they’re not hungry. The University of Georgia’s KittyCam project, which outftted 60 free-roaming pet cats with video cameras, found that only 28 percent of the prey caught was consumed. Half of the kills were simply left in situ — the rest were brought home to lucky owners. 3 Evolved for low-light hunting, cats’ eyes are proportionally enormous. In Cat Sense, John Bradshaw explains that their eye size makes focusing between near and far so diffcult that the muscles develop…

The Stories Behind the Latest Science News FRACTAL FANTASY They’re simple in concept, yet beautifully complex. And nature is full of them — unending geometrical patterns called fractals that, regardless of scale, look the same. Jos Leys, a retired engineer from Antwerp, Belgium, created this 3-D fractal scene using his own formulas and Ultra Fractal, a fractal-generating program. “I am always on the lookout for mathematical theories that can produce images that no one has ever seen,” he says. Creating a scene with these fractal images is a game of trial and error, with slightly different initial conditions producing entirely different images. — ERNIE MASTROIANNI, IMAGE BY JOS LEYS…

It’s an oddity of physiology Humans can’t tickle themselves. Studies suggest this stems from the brain’s ability to predict sensations caused by our own movements, removing the surprise necessary for a good tickle. But George Van Doorn, a psychologist at Federation University in Australia, wanted to find out if the brain’s predictive power really explains why we can’t tickle ourselves. It’s a serious question, since tickling gives us a clue as to how the brain processes sensations, and can even teach us a bit about mental illness. (People with schizophrenia, for instance, actually can tickle themselves, for unknown reasons.) “The dominant theory also suggests that in highly surprising situations, a person will be able to tickle themselves,” Van Doorn says. The brain’s predictive abilities become too poor. To simulate this…

Scientists have long known of the important roles played by the microbes on and in our bodies — our microbiomes. These little guys outnumber our own cells 10 to 1, and they help regulate everything from the energy we get out of food to the health of our immune systems. Now, scientists believe that the bugs help play another important role: the evolution of new species. Vanderbilt University biologists Seth Bordenstein and Robert Brucker were studying what distinguished similar wasp species. Specifcally, they knew two closely related wasp species, Nasonia giraulti and Nasonia longicornis, could produce healthy hybrid offspring and that the two had a similar array of gut bacteria. But when either wasp tried to mate with the related Nasonia vitripennis, which has different gut microbes, those hybrid offspring…

Unraveling Medicine’s Biggest Riddles Free Preview! If you like Discover’s Vital Signs column, take a look at this excerpt of our newest special issue, packed with amazing true stories from doctors and researchers. Everyone Loves a Mystery ... To arrive at a correct diagnosis, a good doctor must bring not only medical knowledge and research to bear, but also review a patient’s symptoms with the deductive powers of a master sleuth. This special preview includes one such mystery on page 26. But frst, turn the page for a glimpse at new methods and tools that could solve future medical conundrums in the years to come.…

Why, after millions of years of steadily lighting the cold darkness, does a supergiant star suddenly explode in a blinding blaze of glory brighter than 100 billion stars? What exotic objects in deep space are firing out particles at by far the highest energies in the universe? And perhaps most mind-bending, why does the universe contain any matter at all? These mysteries have vexed astrophysicists and particle physicists for decades. The key to solving all three deep conundrums is itself one of the greatest enigmas of physics: the neutrino. The universe is awash in these peculiar, nearly massless, subatomic particles. Created in tremendous numbers right after the Big Bang, and constantly churned out in stars and other places by radioactive decay and other reactions, trillions of these ghostly particles sail…

On a summer afternoon, Jose Gomez-Marquez stands in the middle of a Family Dollar store, loading up his basket with colorful plastic toys. Down the aisle, two of his MIT students, Valentina Chamorro and Madeline Aby, are rummaging through kitchen supplies, deciding whether to buy an acrylic toothpick holder. “Remember, it’s only a dollar,” Gomez-Marquez says. “You might not know what you’re going to use it for now, but it’ll cost more than a dollar for us to come back here.” Gomez-Marquez and his students aren’t shopping for goods so much as ideas. As head of MIT’s Little Devices Lab, Gomez-Marquez invents unconventional, affordable medical technologies for communities in need, replicating the functionality of hundred-thousand-dollar laboratory robotics with Lego Mindstorms kits and cheap, open-source Arduino circuits. On this particular Thursday,…

DISCOVER: Did you go into the project with a specific target audience among parents in mind? MR: We were hoping to reach parents with young children, both those who vaccinate routinely and those who may harbor some doubts. Some of those parents turn off if they think they’re being lectured to, so we tried to craft a flim that is frank, informative and accessible. DISCOVER: Was it a conscious decision on your part to seek out measured, moderate comments? MR: We deliberately tried to avoid the way this issue has often been framed, as a virtual war between forces for and against vaccination. The fact is, that’s a pretty misleading perspective. Most Americans vaccinate their kids on schedule, and those who don’t are in the minority. And, of course, all…

Passenger Pigeon Lost Flocks of billions once darkened skies for hours at a time, but overhunting and habitat loss drove passenger pigeons to extinction. Martha, the last of the species, died in captivity 100 years ago today. passengerpigeon.org 9/3 Born to Be Wild The National Museum of Natural History celebrates the 50th anniversary of the Wilderness Act with “Wilderness Forever,” a juried exhibition of images of wild America. tinyurl. com/NHMWilderness 9/3–9/4 Big Birthday Bash Rocky Mountain National Park in Colorado kicks off a yearlong centennial celebration with a picnic and other festivities. Anniversary events continue at the park through September 2015. nps.gov/romo/planyourvisit/100th_anniversary.htm 9/6 Lunar Viewing Get out and howl at the moon — or just take in the view — for International Observe the Moon Night. mainestatemuseum.org 9/10 Creepy Crawlies…