DiscoverOctober 2016的目錄

In 1822, a well-placed arrow solved the mystery of why some European birds would vanish after summer and reappear in spring. A hunter in Mecklenburg, Germany, killed a white stork that already had an African projectile lodged in its neck. Nearly two centuries later, European researchers are trying to explain a new phenomenon: Why have many storks stopped migrating? Roughly 14,000 of the fairweather fowl in Portugal have given up flying south. In a recent study published in the journal Movement Ecology, conservation ecologists used GPS tags to track 17 of those white storks through their normal migration period to figure out why. Instead of heading to sub-Saharan Africa, the birds made regular trips from their permanent nests to landfills dozens of miles away — something previously unheard of. Aldina…

The initiative enables cancer centers to access and analyze vast amounts of anonymous patient information — from genetic sequences and imaging data to findings in personal health records. Eric Dishman, a former Intel executive now at the National Institutes of Health, was a 19-yearold college sophomore when he was diagnosed with a rare form of kidney cancer. Over the course of the next 23 years, he would receive 62 different kinds of chemotherapy, immunotherapy and radiation. Some slowed the tumor’s growth, but never for long. The cancer spread from his left kidney to right kidney. Just when it seemed Dishman had run out of options, a chance encounter in 2012 with a scientist working for a now-defunct genometesting company presented an opportunity he couldn’t refuse. He had his cancerous tissue…

In the rehearsal space of the Boston band What She Said, Earl Miller lays into his bass guitar, plucking out a funky groove. He sticks out his tongue Mick Jagger style, as the band’s drummer hammers away behind him, clowning it up for photos splashed onto social media. In a black band tee, faded cargo pants and signature newsboy cap, Miller looks like a seasoned musician you’d see in any corner dive bar. But at his nearby office at MIT, Miller is nothing if not professorial. How could that rocker in the cap be the same bookish academic now gazing solemnly at me across his paper-strewn desk at the Picower Institute for Learning and Memory? The jarring contrast between the two Earl Millers is a fitting way to begin a…

Some astronomers have a knack for making it seem like humans have truly become masters of the universe. They built the Gaia space observatory, currently scrutinizing a billion stars to create the definitive map of the Milky Way. They detected ripples in space and time caused by black holes crashing into each other in a distant galaxy. They have analyzed the afterglow of the Big Bang — the very beginning of existence! — to measure the precise amount of matter and energy in the entire universe. And then there is astronomer Mike Brown of Caltech, always ready to deliver a dose of humility. His specialty is exploring the outer reaches of our solar system, a mere 1/1,000th the distance to the sun’s nearest star, and finding it full of shadowy…

FOR BILLIONS OF YEARS, IT WAITED. A city-sized chunk of primordial space rock circled the solar system somewhere between the orbits of Mars and Jupiter. Earth took shape. Life evolved. And all the while, the space rock just drifted, tumbling end over end like a poorly thrown football. Then, some unknown celestial mechanics shoved this 9-mile-wide projectile out of its orbit. Destination: Earth. The asteroid belt escapee arrived 66 million years ago. In those last dinosaur days, any skygazing T. rex might have tilted its head in curiosity as a strange, new star grew dozens of times brighter than the sun. Burning through the atmosphere at 45,000 mph, the asteroid’s leading edge hit the Gulf of Mexico while its other end was still higher than a cruising 747. It excavated…

One night 40 years ago, in the spring of 1976, planetary astronomer Fred Franklin walked up the four flights of stairs from his office to the Harvard College Observatory in Cambridge, Massachusetts, and entered the dome of the 9-inch Alvan Clark refractor — where he changed my life with a question. “Steve, do you think you can detect a one-tenth-magnitude brightness difference in Saturn’s A ring?” he asked. I looked at him, puzzled, and asked, “Do you mean if I can see Encke’s Division with the 9-inch?” The division is an anemic split near the outer edge of ring A, which requires excellent atmospheric stability to spy. “No.” Fred shook his head, explaining that the brightness of Saturn’s A ring is not constant but varies at four points, with two…

It’s spring, but frost covers nearly half the boat ferrying Clint Muhlfeld and his crew across Quartz Lake, high in the mountains of Montana’s Glacier National Park. They hiked 6 miles to meet the flatbottomed skiff — which was strapped to the bottom of a helicopter and flown in — and carried nets, food, gear and gas because mules couldn’t cross the streams swollen with snowmelt. They’re here to tag an invasive species. The arduous trip is one of many biologists have made to the park’s lakes in recent years, part of an ongoing search-and-destroy mission to rein in one of the most pernicious aquatic threats in the West: lake trout. The sport fish, introduced in lakes over the past 100 years, have outcompeted native bull trout in many of…

In 2007, a wildlife biologist working for the National Park Service at the Grand Canyon discovered one of the collared mountain lions he had been tracking. The animal was dead. Concerned, he removed the lion’s body, took it home and performed a post-mortem examination. Within a week, he was dead, too. The cause of death for both: Yersinia pestis, commonly known as plague. The deaths, along with dozens of cases since, are a vivid reminder that the disease is alive and well. Y. pestis is a bacterium that lives in the bellies of fleas, which live on rodents, some of which, like rats, live near humans. Scholars estimate that plague killed up to half the European population during the Middle Ages, and for most the death was a painful, slow…

Ever heard of the Ignorosphere? It’s what scientists have jokingly nicknamed the mesosphere, the third atmospheric layer from Earth’s surface. It’s always been tough for researchers to access and so has been largely ignored. But that’s about to change, thanks to work done by Project PoSSUM (Polar Suborbital Science in the Upper Mesosphere). While unmanned rockets, satellites and balloons — most notably NASA’s AIM satellite — have taken images of and collected data from the layer in the past, new suborbital vehicles will make it possible to send actual human scientists to the mesosphere to study noctilucent (NLC) clouds. These ragged, spidery clouds began appearing in the late 1800s, and their increasing frequency and geographic spread are believed to be a marker for climate change. They’ve been difficult to study,…

Q Are we any closer to understanding the root cause of gravity between objects with mass? Can we use our newly discovered knowledge of the Higgs boson or gravitational waves to perhaps negate mass or create/negate gravity? — Jeff Lepler, Redford, Michigan A Sorry, Jeff, but scientists still don’t really know why gravity works. In a way, they’ve just barely figured out how it works. The Higgs boson discovery four years ago helped verify how objects acquired their mass, but that doesn’t shed much light on gravity itself. In the 17th century, Isaac Newton was the first to formally connect an apple falling toward Earth and Earth itself “falling” around the sun. The force behind both was gravity, and Newton understood it as just an attraction that grew stronger between…

Telomeres are tiny fragments of DNA at the end of each chromosome. Nobel laureate Elizabeth Blackburn has spent her career studying their function. Here, she talks about the role they play in aging. DISCOVER: Are telomeres the clock behind aging? BLACKBURN: As a loose approximation, aging is clocklike because there’s a progressiveness to it. But we’ve got to be smarter about what that word aging really means. Is human aging your risk of getting the diseases of aging? Well, in that case, centenarians never age. And yet, they clearly do age: They get wrinkled and frail and smaller — they’re doing well but they’re not young people. Aging has multiple aspects, and we tend to oversimplify it. A lot of different kinds of things come into play in different stages.…

Fossils from New Mexico and Colorado show that the doomsday asteroid of 66 million years ago may have caused entire forests to burn to the ground. And for decades, some scientists thought that happened because the atmosphere superheated the planet, igniting fires everywhere on Earth as fireballs rained down from the skies. But David Kring of the Lunar and Planetary Institute has modeled Chicxulub’s immediate aftermath and shown forest fires were likely more regional — some forests lived, while others died. His team proposes that a thermal pulse is to blame, an explosion of heat reaching more than 36,000 degrees Fahrenheit as it spread from the impact site, igniting nearby areas. If that’s correct, forest fires likely spread across southern North America, but stopped before destroying the continent’s northern reaches.…

To witness this total eclipse in 2002, viewers had to travel to Australia. It’s an event that hasn’t been seen from the U.S. mainland since 1979, but next Aug. 21, an eclipse will go coast to coast. Its path will cross 10 states, giving millions the chance to witness one of nature’s greatest spectacles without getting a passport stamp — so start preparing now with the 25 solar eclipse viewing tips by Astronomy Senior Editor Michael E. Bakich on page 58. For a different kind of observing, see page 62 to learn how Stephen James O’Meara’s uncanny eyesight detected details in Saturn’s rings that could only be confirmed by spacecraft. And for the future of sky-watching, see Eric Betz’s story on page 66 about the growing network of roof cameras…

Steve Schoner once spent 17 years looking for a single rock. He crisscrossed thousands of miles in hundreds of days walking the area around Glorieta Mountain in New Mexico. Along the way, he fell down a cliff, was confronted by a bear, hid from drug smugglers in the dark and saw more rattlesnakes than he could count. Most of the time, he hiked alone, watching the ground and listening for telltale beeps from a metal detector — sounds he hoped would lead him to a 40-pound (18 kilograms) asteroid remnant richly laden with yellow-hued stones. Schoner was among the most prolific meteorite hunters in the Southwest from the early 1970s until a rare brain disease nearly claimed his life in 2003. He searched then for what he still searches for…