Innholdsfortegnelse for Apr-15 i National Geographic Magazine

While airlines may set the fares and fees for air travel, the decisions made by passengers also come with costs. Every item on board makes a plane heavier, which burns more fuel. An airliner’s cost of operating rises with every laptop (70 cents per flight), pillow (12 cents), or magazine (11 cents) you bring along. Want your flight to burn less fuel? Start by emptying your bladder before boarding. MIT aeronautical engineers Luke Jensen and Brian Yutko used a set of typical U.S. and European flight conditions to analyze how specific items add up on three major carriers (United, American, and Ryanair) over a normal day. Uncertainties abound, such as the price of fuel or the cost of an unexpected detour. And even if passengers help reduce weight, airlines don’t…

In summer 2014, while tracking a rare Andean bear in Ecuador’s Cayambe Coca National Park, scientists noticed that her activity centered on one area—a possible sign of nesting. They later found her cub. The animals, known also as spectacled bears for their facial markings, belong to the only wild bear species in South America; by some estimates, fewer than 3,000 now live in Ecuador. Ongoing observations of this cub will shape efforts to save the solitary, vulnerable species and perhaps boost its numbers.…

After two centuries abroad, Mexico’s first sweeping, native-authored history is back home again. Last fall the National Institute of Anthropology and History acquired three 17th-century volumes—two written in Spanish; the third, the Codex Chimalpahin (below left), in Nahuatl—from the British and Foreign Bible Society. In 1827 a priest traded the vivid, handwritten accounts of life, society, and politics in Aztec Mexico for a stack of Bibles. Now that the tomes have returned to Mexico, historians there can get a fresh look at their country’s pre-Hispanic past.…

A genteel disquisition on love and lust in the animal kingdom Drawing his chin along her skin. Coiling his body about hers. Jerking his head seductively, biting her, and vibrating his tail. In the Kama Sutra of snake sex, these are prime mating moves among colubroids, the world’s largest family grouping of snakes with some 2,500 species. To see how snake courtship evolved, herpetologist and paleontologist Phil Senter studied data on 76 snakes of the Colubroidea and Boidae groups. From research that included studies of fossil records dating to the Cretaceous period, he found that some colubroid comeons are ancient—chin-rubbing, jerking—while the “coital bite” and “tail quiver” began later. In all, he says, it’s “quite the set of dance moves.” The snake-atop-snake courtship position called mounting is “nearly universal” in…

The gunman at the jungle’s edge lived and died by different names. Some knew him as Prashant, others as Paramjeet. Occasionally he called himself Gopalji, trading the alias with another insurgent leader to further confuse the Indian authorities trying to hunt him down. When I met him, he was fresh from killing, and called himself by yet another name. “Comrade Manas,” he said as he stepped from the shadows beneath a huge walnut tree, machine gun in hand, a slight figure, his frame and features burned out and cadaverous with the depredations of malaria and typhoid, war and jungle. The day was already old and the sun low. The silhouettes of a dozen or so other gunmen lurked in the deepening green of the nearby paddy fields, watchful and waiting.…

Argentina is a promised land blessed with incredible beauty and potential. I wanted to create a project that would emphasize its diversity, foster conservation, and empower rural communities to reach their productive and social potential. To support this work, I created a foundation called Biophilia (biophilia-foundation.org), which means a love for life. Since I moved here from Italy ten years ago, I’ve seen Argentina’s economy become more and more focused on the large-scale cultivation of genetically modified soybeans. This is tragic, in terms of both culture and biodiversity. I felt the need to do something about this by working to create an alternative approach to a more sustainable future. So on December 27, 2013, my wife, Juli, and I began a five-month journey across the country. We worked with rural…

More than one million swimming pools gleam from California’s backyards. With the state in its fourth year of drought, these residential oases have become a target of local water restrictions. Yet pools can waste less water than traditional lawns, research has shown. “The big thing with a pool is that you fill it once,” says Jonathan Volzke, spokesperson for the Santa Margarita Water District in Orange County, which rolled back its pool prohibitions after analyzing water usage. Pools are also usually surrounded by decks, which means an area up to three times the size of the pool no longer requires any water at all. Add a cover to prevent evaporation, and a pool can use even less water over time than drought-tolerant landscaping.…

Climate change is threatening some of North America’s most beloved birds. According to a recent Audubon Society report, by 2080 shifting temperatures could greatly reduce the habitats of ten U.S. state birds. Since bird populations are indicators of ecosystem health, it’s important to track their numbers to determine where conservation efforts are needed most. Bird-watchers are helping by uploading as many as eight million bird sightings every month to eBird, an online database with nearly 250 million records. Mark Reynolds of the Nature Conservancy says crowdsourcing is one tool for saving fleeting habitats.…

At 7:35 a.m. on November 13, 1872, in the port city of Le Havre, France, the art world changed forever. Claude Monet gazed out his hotel window and began to paint what he saw. The result (above) was “Impression, Soleil Levant” (“Impression, Sunrise”)—and the birth of a movement. How do we know exactly when Impressionism began? Because of Donald Olson, a Texas State University astrophysicist who uses astronomy to solve art and literary mysteries. When art historian Géraldine Lefebvre and Marmottan Monet Museum deputy director Marianne Mathieu asked Olson to help determine the painting’s provenance, the self-styled “celestial sleuth” began by poring over maps and photos to identify Monet’s hotel and room. Then he turned to astronomy—using the rising sun and the moon to determine the tide, season, and time…

We here highly resolve that... government of the people, by the people, for the people, shall not perish from the earth. —Abraham Lincoln, Gettysburg Address, November 19, 1863 Let us have faith that right makes might, and in that faith, let us, to the end, dare to do our duty as we understand it. —Abraham Lincoln, Cooper Union Address, February 27, 1860 The black box nestles deep beneath the U.S. Capitol, encased behind thick glass, caged by a metal grille, as if it were a dangerous object, a ticking bomb primed for its inevitable explosion. Perhaps in a sense it is. In April 1865 carpenters constructed this velvet-draped bier, known as the Lincoln catafalque, to display the murdered president’s casket in the building’s Rotunda; its dark cloth conceals the rough…

ONE CHILLY MORNING in October 2013, Diana Six parked her white Subaru at the edge of a pine forest in southwestern Montana’s Big Hole Valley. Beneath snow-tipped peaks, lodgepole pines in four different colors draped the hillside—a time line of carnage. The gray ones, now just trunks and branches, had died in 2009. Light red trees, still holding needles, had succumbed in 2011. Darker, auburn trees had perished in 2012. Even the seemingly healthy green trees, said Six, a ponytailed, bodybuilding, beer-brewing entomologist at the University of Montana, were not what they seemed. Roughly a quarter of them were already doomed. Six zipped her jacket and ambled into the woods with an ax. She stopped at a mixed stand of emerald and burnt-orange lodgepoles. With the ax blade, she gently…

The Longing for Lincoln Doris Kearns Goodwin, the best-selling chronicler of America’s presidents, knows the question historians would expect her to ask Abraham Lincoln if she could. How would you have dealt with Reconstruction differently than Andrew Johnson? the dutiful Goodwin would inquire. Lincoln’s death cut short what probably would have been a gentler approach to the South after the Civil War, she explains. If he’d lived, “it might have helped ease the racial tension that’s lasted for hundreds of years.” But given the chance to actually sit down with our 16th and, arguably, greatest president, Goodwin would ask something very different. “I would just say to him, Tell me a story,” she says. “The minute he started telling a story, his eyes would light up, as if he had…

With their striking coat patterns and towering height, giraffes are iconic African creatures—yet they haven’t been the subject of much scientific study. Now researchers who track the animals report a disturbing trend: Across the continent populations have dwindled from 140,000 to fewer than 80,000 over the past 15 years, according to the Giraffe Conservation Foundation (GCF). Slow-moving and enormous, “giraffes offer an easy target and lots of meat” for poachers, particularly in the war-torn Democratic Republic of the Congo, says GCF Executive Director Julian Fennessy. Herds also are diminished by habitat loss and by hunters who cater to the superstition among some tribes that eating giraffe brains wards off HIV. Still, says Fennessy, there is hope for the future. “We wouldn’t be doing this work if we thought it was…

A Mural’s New Date Surreal life-size figures on a sandstone wall in Utah’s Horseshoe Canyon may be thousands of years younger than experts estimated. Using new techniques to gauge how long rocks had been exposed to sunlight, researchers significantly narrowed the period in which the mural must have been painted. Their reconstruction of events: 2,000 years ago a sheet of rock fell from the cliff. Artists then used the fresh surface as their canvas. About 900 years ago another sheet fell, taking a few painted figures with it. Steven Simms, a Utah State University archaeologist involved in the research, thinks the paintings may have been made within a few hundred years of the first rockfall, during a time of major transformation as corn farmers from the south moved into a…

Flying was still in its intrepid, barnstorming days in the mid-1920s when the U.S. Department of Commerce began establishing airways, prescribed routes in the sky, to promote air commerce. How did pilots navigate their way cross-country in planes—some of them left over from World War I—that had only rudimentary instruments? Often by peering down from the cockpit to look for the big concrete arrows pointing the way. It may have been either a slightly crazy or brilliantly simple scheme, or both. More than a thousand concrete arrows were installed along the federal airway system, says Phil Edwards, a technical information specialist at the Smithsonian National Air and Space Museum Library. Up to 70 feet long and painted yellow or other highly visible colors, arrows were placed 10 to 15 miles…

It didn’t amount to much at first. Launched into orbit aboard the space shuttle Discovery on April 24, 1990, amid flurries of hope and hype, the Hubble Space Telescope promptly faltered. Rather than remaining locked on its celestial targets, it trembled and shook, quaking like a photophobic vampire whenever sunlight struck its solar panels. Opening its protective front door to let starlight in perturbed the telescope so badly that it fell into an electronic coma. Worst of all, Hubble turned out to be myopic. Its primary light-gathering mirror, eight feet in diameter and said to be the smoothest large object ever fashioned by humans, had been figured perfectly wrong. Its design was already a compromise. The astronomers had wanted a bigger telescope in a higher orbit. They got a smaller…

AT 126 FEET TALL, CUT FROM MARBLE, ADORNED WITH A SPIRAL FRIEZE INTRICATELY CARVED WITH 155 SCENES, In back-to-back wars fought between A.D. 101 and 106, the emperor Trajan mustered tens of thousands of Roman troops, crossed the Danube River on two of the longest bridges the ancient world had ever seen, defeated a mighty barbarian empire on its mountainous home turf twice, then systematically wiped it from the face of Europe. Trajan’s war on the Dacians, a civilization in what is now Romania, was the defining event of his 19-year rule. The loot he brought back was staggering. One contemporary chronicler boasted that the conquest yielded a half million pounds of gold and a million pounds of silver, not to mention a fertile new province. The booty changed the…

nationalgeographic.com/3Q Francis S. Collins, a physician and the geneticist behind the Human Genome Project, is the director of the National Institutes of Health. He is also founder of the BioLogos Foundation (biologos.org), a group that fosters discussions about the intersection of Christianity and science. Are science and religion compatible? I am privileged to be somebody who tries to understand nature using the tools of science. But it is also clear that there are some really important questions that science cannot really answer, such as: Why is there something instead of nothing? Why are we here? In those domains I have found that faith provides a better path to answers. I find it oddly anachronistic that in today’s culture there seems to be a widespread presumption that scientific and spiritual views…