Sommaire pour September 2013 de Discover

Don’t be shy about sharing your opinions, whether via letters, email or our social media communities. Here’s what you’ve been telling us lately. Shark Hunt Hatred Erik Vance wrote about the declining shark population in our June cover story. I read your great article, “Desperately Seeking Sharks.” I’m 17 years old. I want to do marine conservation biology. I already know about shark-finning, but after reading your article I was upset at how fast the shark population is declining. Tonight (6/5/13) on CNN on Piers Morgan Live, I was horrified to see him glorifying the capture and killing of a mako shark for sport. I hope your article will raise awareness of the decreasing population of sharks and help to save the species. Saoirse Keely-Zinkel Madison, WI Counting Off July/August’s…

Downtown Tucson and the Santa Catalina Mountains loom in the distance in this October 2000 photo showing an excavation at Julian Wash in Arizona. Once dismissed as a probable trash heap, the site is now recognized as a large Hohokam village from about A.D. 750 to 1150, and it is a shining example of preservation archaeology, in which sites are excavated and preserved in concert with development. After Arizona made plans to rebuild an interstate exchange at the Julian Wash site, archaeologists and the state established a two-stage preservation plan. Researchers first excavated a strip of land that held hundreds of dwellings as well as other artifacts, according to William Doelle of Desert Archaeology Inc. The interstate was subsequently built over these parcels, and nearly 17 additional acres near the…

The solar corona, our sun’s energetic atmosphere, has long baffled scientists who don’t understand how it gets all that energy. “We call it the coronal heating problem,” says Jonathan Cirtain, an astrophysicist at NASA’s Marshall Flight Center in Huntsville, Ala. “Why is the surface of the sun 6,000 Kelvin while the corona is 7 million Kelvin?” Cirtain and a team of researchers have helped solve the mystery using the highest-resolution images ever taken of the corona. In July 2012, the researchers launched a telescope less than 10 inches in diameter — dubbed the High-Resolution Coronal Imager, or Hi-C — 174 miles above Earth. The Hi-C spent only five minutes observing the sun before parachuting back to White Sands Missile Range in New Mexico, but it yielded remarkable results. The team…

What does salad dressing have in common with building conservation? Olive oil. Researchers led by Karen Wilson in Cardiff, Wales, discovered that oleic acid, a component of the food staple, has just the right properties to make an excellent coating to help preserve historic structures. Some great historic buildings, such as the York Minster cathedral in England (pictured), are made from limestone, a popular material because it was cheap, plentiful and easy to build with. Unfortunately, limestone is also extremely vulnerable to pollution, especially acid rain. Previous attempts at creating protective coatings failed because they were too thick: They blocked pollutants, but also prevented limestone from expanding and contracting with changes in temperature, leading to structural damage. The new oleic acid coating is inherently hydrophobic, repelling water and any pollutants,…

Pull apart any electrical device and you will find a riot of right angles, straight lines and flat, uncompromising silicon wafers. John Rogers is changing that. The 45-year-old materials scientist has spent more than 15 years developing electronics that can bend and stretch without breaking. His devices, from surgical sutures that monitor skin temperature to biodegradable sensors that dissolve when their useful life is done, share a unifying quality: They can slip seamlessly into the soft, moist, moving conditions of the living world. Other scientists construct flexible electronics from innately bendy materials such as graphene, a lattice of pure carbon only one atom thick. From his lab at the University of Illinois at Urbana-Champaign, Rogers has bucked the trend, building most of his devices from silicon, a normally rigid material…

So far, the odds look good. FOR THE FIRST TIME IN OVER A decade, a striking silence fills the Cheevers’ barn-style home in North Andover, Mass. The deep, rumbling cough that plagued sisters Laura, 14, and Cate, 12, every night of their lives, leaving them exhausted and weak, has finally stopped. Their bodies are almost free of the lifethreatening lung infections — requiring hospitalization and harsh organ-pummeling intravenous antibiotics — which end the lives of so many children with cystic fibrosis. Now calories once spent fighting disease add weight on their dainty frames and give them energy to play soccer and dance. “And,” says Rob Cheevers, Laura and Cate’s father, “they don’t taste salty anymore.” “Yeah, I taste like an average person,” quips Cate, referring to the salty sweat that…

The practice of assembling bestiaries — compendiums of animal lore and knowledge — began in medieval times. They were lavishly illustrated volumes, lettered by monastics on vellum, edged with hand-mixed colors and gilt. They blended medieval science — what was believed to be factually true about each animal — with unreservedly fanciful descriptions. Penned in the 12th century, the Aberdeen Bestiary’s entry for beavers exhibits the classic medieval bestiary components of observation, imagination and allegory. The beaver is accurately described as possessing a tail that is flat like a fish’s and fur that is soft like an otter’s. The animal was prized for its testicles, which were said to contain a potent liquid that could cure headache, fever and “hysteria.” (This liquid would have been castoreum, located in a small…

Director and writer Neill Blomkamp rocketed into the public eye with 2009’s gripping and inventive District 9, a sci-fi flick set in his native Johannesburg. The movie had all the whiz-bang effects and zap-happy gunfights we expect from the genre, but strong acting and a storyline evocative of apartheid-era South Africa won it critical acclaim as well. Blomkamp is back at the helm with the dystopian Elysium, due in theaters Aug. 9. He’s got big stars — Jodie Foster and a bald Matt Damon — and a big budget, estimated to be more than three times the size of District 9’s modest $30 million price tag. But one thing Blomkamp says he doesn’t have is a big worry about meeting stratospheric expectations for the movie. Blomkamp explained to DISCOVER Associate…

Lukewarm coffee. In the grand scheme of life, it’s a mild vexation, but the same sustainable, nontoxic material that keeps babies warm and soldiers cool can now ensure your cappuccino stays at optimal drinking temperature for hours. PureTemp, a technology developed by Minnesotabased Entropy Solutions, turns vegetable oils into phase change material (PCM) capable of maintaining a specific temperature between minus 40 and 300 degrees for hours. PCMs have been around longer than our species: Water’s transition from a solid to a liquid at the phase change point of 32 degrees is the most obvious example. So we asked PureTemp Chief Chemical Officer William “Rusty” Sutterlin to explain what’s so cool about this hot new take on phase change. READ OIL ABOUT IT: PureTemp technology involves purifying a variety of…

Sept2013 National Food Safety Month Each year, foodborne illness sickens 48 million Americans, but restaurants aren’t the only culprits. Do you practice food safety at home? foodsafetymonth.com 9/6 Riddick in Theaters Vin Diesel returns as everyone’s favorite slytongued anti-hero with built-in night vision in the third feature-length outing for the sci-fi franchise that started with 2000’s Pitch Black. RiddickMovie.com 9/8 – 9/12 High-Speed Science Ride with the American Chemical Society at its national meeting in Indianapolis as researchers investigate the science behind racecars. Fee and registration required. http://tinyurl.com/ACSNatlMeeting 9/11 Ground Zero Skyscraper Airs on PBS NOVA examines the engineering feats of the new One World Trade Center. pbs.org/wgbh/nova 9/14 Epicurean Entomology At Café Insecta, part of Bugfest at the North Carolina Museum of Natural Sciences, “Ants on a Log” aren’t…

Here at DISCOVER, we see change as a big part of our job. Over the past few months, the team here has introduced a variety of tweaks to the magazine and website. But this issue heralds a bit of an upgrade, with a new look and new elements that we’re eager to share with our readers. Whenever a magazine undergoes a redesign, this is the spot where the editor starts justifying the revamp, perhaps with a reference to Darwin, or by making use of a handy pop-culture reference — comparing the change to, say, the regeneration of the Doctor from Britain’s popular Doctor Who TV series. Same character you know and love, just a new look and some added personality traits! I would never do that, of course. Instead, I…

Two of DiscoVer’s bloggers answer our first round of questions. Q Why don’t we know when we’re dreaming, especially when we interact with dead characters? My dad died a long time ago, yet when he inhabits my dreams, it seems perfectly normal. Do we all become morons when dreaming? —Alan Schertzer A This is a very good question. The dreaming brain’s activity is largely similar to that found when awake, but some areas of the brain are less active in dreams. In particular, activity in a region called the precuneus is lower — and this area has been linked to conscious experience. In one study, activity in the precuneus was higher during lucid dreams (in which you are aware of being asleep) than normal dreams. So the precuneus, and perhaps…

In a first, researchers in Japan have captured the brain activity of a living animal as it pursues its prey. “Seeing is believing,” says Koichi Kawakami, a molecular and developmental biologist at Japan’s National Institute of Genetics. In the past, he says, researchers have had to infer brain processes indirectly, by watching behavior and surmising what the brain must be doing. That makes his feat a big improvement. “Nothing is better than direct observation,” he says. For years, researchers have regarded the ability to watch an organism’s neurons fire — at high resolution, as the animal behaves naturally — as the pinnacle of brain observation. In humans, neuroimaging techniques show brain activity, but the methods aren’t fast or fine-grained enough to give a clear picture, Kawakami says. Attempts on mice…

Earlier this year, as astronauts busied themselves inside the International Space Station, engineers on the ground conducted their own experiment just outside the craft. Operating from a control room in Houston, they directed a nearly 60-foot-long, Canadian-built robotic arm to grab a smaller, two-armed robot called Dextre, before moving it into position in front of a washing machine-size module attached to the station. Then, Dextre reached into the module, grabbed one of four toaster-size, custom-made, high-tech tools there, and proceeded to snip two safety wires, unscrew two filler caps on the outside of the module and pump a few liters of ethanol into a small holding tank. The Jan. 25 exercise wasn’t especially dramatic — it made no headlines. But the maneuvers, formally known as the Robotic Refueling Mission, represent…

The question presupposes that the universe had an actual starting point, but one might just as well assume the universe always was and always will be. In that case, there would be no beginning whatsoever — just an ever-evolving story of which we’re catching a mere glimpse. “We have very good evidence that there was a Big Bang, so the universe as we know it almost certainly started some 14 billion years ago. But was that the absolute beginning, or was there something before it?” asks Alexander Vilenkin, a cosmologist at Tufts University near Boston. It seems like the kind of question that can never be truly answered because every time someone proposes a solution, someone else can keep asking the annoying question: What happened before that? But now Vilenkin…

Cystic fibrosis is a chronic disease that affects the lungs and digestive system of about 30,000 children and adults in the United States (70,000 worldwide). A defective gene and its protein product cause the body to produce unusually thick, sticky mucus that clogs the lungs and leads to lifethreatening lung infections. The mucus also obstructs the pancreas and stops natural enzymes from helping the body break down and absorb food. Normal Airway: In healthy lungs, the airway is lined with thin layer of mucus Airway With CF: With cystic fibrosis, thick, sticky mucus blocks the airway.…

In winter 2010, Adrian Glover, a marine biologist from the Natural History Museum in London, got a call from a colleague with some good news. While piloting a remotely operated vehicle to study a hydrothermal vent 4,700 feet beneath the surface of the Antarctic’s Scotia Sea, his friend had stumbled across something unexpected: the skeleton of an Antarctic minke whale. Rather than being a scene of death, the carcass was an oasis of life in the dark and inhospitable remote sea. Snails, worms, mollusks and white mats of bacteria were feasting on what remained of the massive mammal. Glover asked his friend to bring home a piece of this treasure. While inspecting the bones in his lab, he discovered nine new species of worms and bacteria. These rare, relatively unexplored,…

ABOMINABLE SCIENCE! By Daniel Loxton and Donald R. Prothero It probably wasn’t Bigfoot you heard go bump in the night, but wouldn’t it be cool if science could prove it was? Skipping cryptozoology’s usual sensationalism, Abominable separates history and folklore from hoaxes and fakelore. Discussion of the yeti, Nessie and their ilk includes analysis of “believer” psychology, exploring what’s behind faith in the fantastic. Occasionally wry but never mean-spirited, skeptics Loxton and Prothero press the field’s proponents to approach their subjects with the scientific rigor necessary to be taken seriously. — ELISA NECKAR TELLING OUR WAY TO THE SEA By Aaron Hirsh In his first book, evolutionary biologist Hirsh dives into the murky issues surrounding the conflicted history and uncertain future of Mexico’s Sea of Cortez. Students accompanying him to…

Is it a w or an n? Panic sets in quickly. My promotion to lieutenant and, I might add, the future of the planet may depend on it. I am a cadet in the Old Weather Navy, a joint U.S.-U.K. web-based project that recruits citizen scientists to decipher the climate data recorded in old ship logs. Climate modeling is fiendishly difficult not only because of its innate complexity but also because of the paucity of historical data. Climatologists have long coveted the wealth and precision of weather observations contained in antique logbooks. Sailors measured winds, temperatures, barometric pressure and cloud conditions as well as sea ice and animal sightings. Not only is the data detailed and meticulous, it is considered highly reliable. The lives of the sailors themselves depended on…

1. Alfred Nobel considered himself a failure. After a newspaper’s premature obituary dubbed him “the merchant of death,” the inventor of dynamite set out to improve his reputation by establishing prizes in peace, literature and the sciences. 2. Only one scientist has won a Nobel for failing. In the 1880s, Albert Michelson tried to measure the “luminiferous ether” that scientists thought was the carrier of light. He couldn’t find it, because it didn’t exist. Michelson had inadvertently discovered that light carries itself, though it would take a patent office clerk named Albert Einstein to explain it. The short version: E = mc2. 3. Several scientific journals now specialize in publishing failed experiments, including the Journal of Negative Results in Biomedicine and the Journal of Articles in Support of the Null…

Stars cook up nearly all of the approximately 60 atomic elements in people’s bodies. But exactly how that works remains a mystery. Astrophysicists have developed cutting-edge computer simulations (shown at right) to grapple with an array of related puzzles: • What were stars like when they first appeared in the universe over 13 billion years ago, starting the process of modern element production? • What do we know about the nature of the death of massive stars — signaled by Type II supernovae — that fashion crucial elements such as calcium and oxygen? • How might the burned-out stars called white dwarfs be brought to ruin by other stars in so-called Type la supernovae, inciting the fiery alchemy that yielded much of the iron in our blood and the potassium…

Since the late 1970s, more than 400 people of all ages in remote areas of China’s southwestern Yunnan province have dropped dead — sometimes in midsentence — from a mysterious cause, mostly during the summer. The so-called sudden unexplained deaths (SUDs) seemed to be the result of heart attacks, but no one was sure what was prompting them as only half of the autopsies revealed underlying heart disease. In 2010, Chinese health officials warned that, based on preliminary tests of the victims, the culprit was a dangerously high level of barium in a local edible mushroom, Trogia venenata. The little white mushroom isn’t valuable, but exports of other fungi, including matsutake and porcinis, are a major source of income for Yunnan’s native people; fears of barium poisoning could hurt the…

Tornadoes may be destructive, but even funnel clouds have a silver lining. Inspired by the process that creates natural twisters, electrical engineer Louis Michaud of Canada’s AVEtec Energy Corp. designed a nonpolluting source of swirling power he calls the Atmospheric Vortex Engine. The device can spin waste heat from power plants into usable energy. Instead of directing excess heat into conventional cooling towers that simply disperse it into the air, power plants could usher the heat into the hollow, open-topped tower of a vortex engine. A heat exchanger outside the tower transfers the extra heat (piped in as warm water) to ambient air. When this warmed air is directed into the tower at an angle, it encounters cooler air and produces a circular current. This current funnels air upward into…

It was a sunny summer day in 2010 just outside Houston, and 54-year-old Shirley Dygert was getting ready to skydive for the first time. Though nervous, she felt at ease after meeting her instructor, Dave Hartsock — the man she’d be strapped to as they executed a tandem dive from a plane. When she asked him how often he’d done this, he reassured her, “Hundreds of jumps.” But problems started as soon as Hartsock opened the parachute to stop their firee fall. The chute didn’t open all the way, and the backup parachute got tangled up. As the two neared the ground, Hartsock made a fateful decision, using control toggles to rotate himself so his body would cushion Dygert’s fall. Hartsock’s action dramatically altered the course of both their lives.…

If our universe has been here forever and maintained a stable size, it, too, would have succumbed to the second law. Disorder would have inexorably increased to the point that the universe would now be a smoothed-out, featureless blur. But that’s not what we see at all. Instead, we see a universe filled with grand cosmic structures — galaxies, clusters of galaxies, clusters of clusters called superclusters, and clusters of superclusters called galaxy filaments — some of the latter stretching a billion or more light-years across. For that reason, Vilenkin rules out the cyclic universe picture unless one makes the added assumption that after each cycle of expansion and contraction, the universe ends up somewhat bigger than when it started. The stipulation would leave us with another expanding universe, meaning…

1955 The Cystic Fibrosis Foundation (CFF) is established. 1978 Francis Collins, a resident in internal medicine, becomes interested in CF when he is assigned to care for a newly diagnosed 19-year-old CF patient. Early 1980s Scientists find the DNA marker for Huntington’s disease. This leads researchers to believe they can use a similar approach to find the gene causing CF. 1985 Lap-Chee Tsui of the University of Toronto tracks the CF gene to chromosome 7. 1987 Tsui and Collins join forces. 1989 Tsui and Collins identify the cystic fibrosis transmembrane regulator gene (CFTR) that has been mutated in CF patients. 1990 Collins and James Wilson make a virus capable of carrying the CFTR gene. They hope it will transmit the gene to human patients. 1993 Gene therapy for CF is…

If I were about to be struck by lightning, I’d want to know. If an earthquake were going to shake my house tomorrow, or in 10 years, I sure would appreciate an early warning. Residents of Chelyabinsk, Siberia, likely felt that way last Feb. 15, when a roughly 15-meter-wide meteor exploded above the Ural Mountains, shattering windows across about 200,000 square meters. More than a thousand people were injured, mostly from glass cuts. Dashboard-camera video of the white-hot rock streaking through the sky, replayed repeatedly on TV and online, boldly illustrated the threat asteroids pose. The footage also highlighted how little we’ve done about it. Just a few hours of advance notice would have made a huge difference in Chelyabinsk, but no observatory on Earth (or beyond) is capable of…

Are you reading this on a smartphone or tablet? Even if you’re not, you’ve probably got a mobile device within reach. Congratulations. You’ve got at least one foot in a brave new world, says author and documentarian Douglas Rushkoff. His most recent book, Present Shock: When Everything Happens Now, explains our cultural transition to “presentism,” a post-clock society enabled by the flexibility and reach of the Internet and those ubiquitous ways to stay connected to it. In a presentist world, we’ll work less but more efficiently and be free from the need for constant economic expansion. Rushkoff told DISCOVER Associate Editor Gemma Tarlach the future is bright for those of us willing to live in the present. Q Are some people confusing the idea of “presentism,” of living in the…

Why does the second-brightest object in the night sky get so little respect? At its peak, Venus outshines Sirius, the most brilliant star, by a factor of 15; only the moon surpasses our sister planet. Yet Venus is routinely mistaken for an airplane, a satellite or even an alien spaceship. Roy Craig’s riveting book UFOs: An Insider’s View of the Official Quest for Evidence, about his investigations for the U.S. Air Force’s Colorado Project, includes an account of veteran police officers in Georgia chasing a mysterious, fast-moving object “about 500 feet above the ground.” Yep, it was Venus. Perhaps people forget about the planet because it disappears for long stretches. Its successive appearances in the evening sky happen 19 months apart. Also, Venus never ventures more than 47 degrees away…