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The sun set on the North Pole more than a month ago, not to rise again until spring. Usually that serves as a cue for sea ice to spread its frozen tentacles across the Arctic Ocean. But in the depths of the polar night, a strange thing started to happen in mid-October. Sea ice growth slowed to a crawl and even started shrinking for a bit. Intense warmth in both the air and oceans is driving the mini-meltdown at a time when Arctic sea ice should be rapidly growing....

The European Association of Medical and Scientific Illustrators (AEIMS) has honored Scientific American illustrator Roberto Osti with the selection of three of his paintings for inclusion in the 2008 Scientific Illustrators Exhibition in Bologna, Italy. The exhibition, which is showing at the Palazzo Poggi in the center of the old town of Bologna, began March 31, 2008 and will run through the end of May 2008. View the slideshow. Four of Osti’s works will also be shown at a new exhibit at the Medialia Gallery, 335 West 38th Street in New York City....

How much does funding affect the course of scientific discovery? In this insightful book, science historian (and Scientific American columnist) Oreskes examines the military backing that poured into oceanography programs during World War II and the cold war. The expansion of naval warfare created a sudden need to better understand the deep sea. Oreskes shows that in some cases, that largesse enriched our knowledge—for example, the need to study the effect of water density on sonar transmission led to a breakthrough in understanding deep ocean circulation....

Editor’s Note (10/07/16): As Hurricane Matthew barrels toward the U.S. coastline, Scientific American reviews some of the science involved in predicting, tracking and understanding these massive storms. This article—originally published on 10/21/2014—looks at the science of monster storms. “Toto, I’ve a feeling we’re not in Kansas anymore,” Dorothy said in The Wizard of Oz after a tornado—that most American of extreme weather events—deposited her into a land over the rainbow. In a typical year some 1,300 real tornadoes rip across the U....

In the U.S., physicians fresh out of medical school regularly work far more hours than those in the U.K. and the European Union. Despite efforts by the Accreditation Council for Graduate Medical Education to cut hours to curtail mistakes, medical residents reported routinely exceeding the limits, based on a survey of 4,000 residents conducted between July 2002 and May 2004. Limit of consecutive work hours for residents in: U.K. and E....

Before June 1, 2013 Turkey’s ruling political party and its leader seemed invincible. They were regarded as the architects of a decade-long economic boom and their public support seemed unshakable. This image shattered in less than a week. They were suddenly described as incompetent and backward with an uncertain political future. On Friday May 31st, a small group gathered at a park in central Istanbul to protest against government plans to replace the park with a housing complex and a shopping mall....

By Lawrence Hurley and Valerie VolcoviciWASHINGTON (Reuters) - The U.S. government’s authority to regulate air pollution nationwide, often against the wishes of Republican-leaning states, could face new curbs when the Supreme Court takes on two high-stakes cases in coming months.The cases focus on the broad-ranging power wielded by the Environmental Protection Agency (EPA) under the landmark Clean Air Act, first enacted in 1970.The law was envisioned as a cooperative effort between the federal government and states in which the EPA sets standards but states have to set plans to comply....

The changing hues of a peacock’s splendid tail feathers have always captivated curious minds. Seventeenth-century English scientist Robert Hooke called them “fantastical,” in part because wetting the feathers caused the colors to disappear. Hooke used the recently invented microscope to investigate the feathers and saw that they were covered with tiny ridges, which he figured might produce the brilliant yellows, greens and blues. Hooke was on the right track. The intense colors of bird plumages, butterfly wings and the bodies of squid are often produced not by light-absorbing pigments but by arrays of tiny structures that are just a few hundred nanometers wide....

When Serggio Lanata moved to San Francisco in 2013, he was stunned by its sprawling tent cities. “Homelessness was everywhere I looked,” he says. Lanata, a neurologist at the University of California, San Francisco (UCSF), was also struck by similarities in the behaviour of some older homeless people and patients he had treated for dementia in the clinic. Now, years later, he is embarking on a study that will examine homeless adults for early signs of Alzheimer’s disease and other degenerative brain disorders to better understand the interplay between these conditions and life on the street....

At least 19 levees in Iowa, Illinois and Missouri have failed over the past week after heavy rains, according to the U.S. Army Corps of Engineers—and workers swarmed to shore up others with sandbags to prevent rising waters in the Mississippi and its tributaries from overflowing and washing away surrounding communities, farmland and soil. Engineers blame overdevelopment—and potentially poor maintenance of the levees—for the flooding. “Whenever you have development, you are going to increase the runoff, increase how much the rivers and streams have to carry,” says civil engineer W....

It’s mid-February and along Britain’s south coast gilt-head bream are drifting from the open sea into the estuaries. Meanwhile, thousands of little egrets are preparing to fly to continental Europe for breeding season, though a few hundred will remain in the UK. Across northern Europe, young wasp spiders will soon scamper out of their silky egg sacs. And this summer, countryside visitors throughout the south of England will catch sight of iridescent blue flashes as small red-eyed damselflies flit across ponds....

Leslie A. Lyons, an assistant professor at the School of Veterinary Medicine at the University of California, Davis, explains. Over the course of evolution, purring has probably offered some selective advantage to cats. Most felid species produce a “purr-like” vocalization. In domestic cats, purring is most noticeable when an animal is nursing her kittens or when humans provide social contact via petting, stroking or feeding. Although we assume that a cat’s purr is an expression of pleasure or is a means of communication with its young, perhaps the reasons for purring can be deciphered from the more stressful moments in a cat’s life....

Global climate change is here, and it’s only going to get worse, according to a White House report released on Tuesday. To combat rising sea levels and blistering summers, the Obama administration has been pushing for clean, renewable energy sources that cut down on carbon emissions. Now one of its projects is poised to pan out: Agua Caliente, the largest photovoltaic solar power facility in the world, was completed last week in Arizona....

Wartime medicine is an incredibly challenging setting for the doctors, nurses, and paramedics who practice it: Not only are the injuries frequently serious ones, but the tools at hand are often more limited than in a traditional hospital. Over the centuries, that has meant that battlefield medical personnel have had to innovate. Those wartime practices, in turn, often served to refine medical practice beyond the military. Here are six cases in which wartime clinicians changed the way medicine is practiced more broadly....

This December 7 the United Nations Framework Convention on Climate Change will convene a 12-day meeting in Copen­hagen to confront one question: How do we respond to global warming when the five-year period for reducing carbon emis­sions under the Kyoto Protocol expires in 2012? The U.S. was not a party to Kyoto, but if this country balks once more, Copen­hagen may fail to get productive commitments from other nations as well....

More than a century ago polar explorer Roald Amundsen and his six-man crew became the first to navigate the icy Northwest Passage. This month much larger ships than Amundsen’s will retrace parts of the sea route but not as adventurers. Instead they will begin laying an undersea fiber-optic cable meant to connect Asia and Europe by crossing the Arctic Circle—the shortest practical distance yet for Internet signals traveling between the two continents....

A new treatment may help people with a bizarre medical condition that makes them perpetually sleepy. The findings, detailed Nov. 21 in the journal Science Translational Medicine, may provide relief for the people who sleep constantly and feel exhausted despite caffeine, other stimulants, and several alarm clocks. People with hypersomnia need to sleep about 70 hours a week and have trouble rousing from sleep. When they are awake, they usually feel as if they’ve pulled an all-nighter, and describe it as walking around in a fog....

Disrupted sleep is so commonly a symptom of depression that some of the first things doctors look for in diagnosing depression are insomnia and excessive sleeping. Now, however, scientists have observed for the first time a dysfunctional body clock in the brains of people with depression. People with major depression, also known as clinical depression, show disrupted circadian rhythms across brain regions, according to a new study published today (May 13) in the journal Proceedings of the National Academy of Sciences....

Key Concepts Vibration Frequency Sound Introduction Have you ever tried to make a whistle out of a blade of grass? Or spun around a wooden noisemaker? Making unique sound makers can be lots of fun—and demonstrate some cool science at the same time. This activity will have you buzzing like a bee—and is a perfect one for playing outdoors. Once you understand the basics of how this noisemaker works, you can make a few of different sizes, share them with your friends and form a band of buzzing bees....

Key Concepts Physics Gas Pressure Volume Boyle’s Law Introduction You have probably opened a soda before and had the liquid fizz right up out of the bottle, creating a huge mess. Why does that happen? It has to do with the carbon dioxide gas that is added to the liquid to make it fizzy. Opening the bottle releases the built-up pressure inside, causing the gas-liquid mixture to rush out the bottle....