Posts

Bobby Monacella was tired of sending her two kids to school on buses filled with diesel fumes. Pollution levels inside those iconic yellow buses can be up to 10 times higher than outside. “They’re sitting on the bus for over an hour a day, and when you learn that the emissions are concentrated inside the bus, it’s scary,” said Monacella, who volunteers with the climate advocacy group Mothers out Front. So she teamed up with other moms in Fairfax County, Va....

In the 5 million years since early hominids first emerged from east Africa’s Rift Valley, the Earth’s climate has grown increasingly erratic. Over cycles lasting hundreds of thousands of years, arid regions of central Africa were overrun by forests, forests gave way to grasslands and contiguous landscapes were fractured by deep lakes. It was within the context of this swiftly changing landscape that humans evolved their sizable brains and capacity for adaptive behavior, said Rick Potts, director of the Human Origins Program at the Smithsonian Institution National Museum of Natural History....

Key concepts Water Heat Temperature Water cycle Introduction Have you ever wondered how sweating helps keep you cool on a hot summer day? Sweat, which is mostly water, cools us down when it evaporates. When water evaporates, it changes from a liquid to a gas. The gas carries away heat with it, helping to remove heat from your skin. Not only can evaporation cool down your body, it can also cool down other things, such as chocolate....

Responses to the February issue raised a question about belief: Are people who trust in fact any less closed-minded than those who favor faith? In “Sticker Shock,” Steve Mirsky satirized the Cobb County, Georgia, school board’s attempt to place disclaimer stickers in biology textbooks warning students that they contain material on the theory of evolution. George T. Matzko, chairman of the natural science division at Bob Jones University in South Carolina, suggested “a sticker for Scientific American in the same vein as the column: ‘Warning, this magazine holds to the theory that all phenomena, including origins, can be explained in terms of natural causes and is therefore atheistic in tone and content....

Will community computers soon be replacing public pay phones on city streets? If the winning prototypes from this week’s Reinvent Payphones Design Challenge in New York City are any indication, then yes. The six winners used modern designs and technology to turn anachronistic amenities into digital information hubs. Participants in the city-sponsored contest were charged with creating a prototype that will replace the nearly 11,000 public pay phones in New York’s five boroughs....

A key satellite used in predicting severe weather in the eastern United States, including Atlantic hurricanes, has failed. Last Tuesday evening, the imaging system on the weather satellite known as GOES-East ceased to transmit images. Engineers in the satellite division of the National Oceanic and Atmospheric Administration, which operates the satellite, are working to determine the cause of the problem, said Tom Renkevens, the deputy division chief of the satellite products and services division at the agency....

For years, I’ve grumbled to myself about an irritating tendency in science punditry. I haven’t written about it before, because it’s subtle, even paradoxical, and I couldn’t think of a catchy phrase to describe it. One I’ve toyed with is “premature ethical fretting,” which is clunky and vague. I’m venting now because I’ve discovered a phrase that elegantly captures my peeve: wishful worries. The problem arises when pundits concerned about possible social and ethical downsides of a technology exaggerate its technical feasibility....

Cutting back on air-conditioning, turning off extra lights and sorting your recyclables can make you feel like you’re doing your bit for the environment. But if you’re already making a few such sacrifices, you may be less inclined when asked to make still more—supporting, for instance, government measures to mitigate climate change. New research has found that individuals who took sustainability measures at home develop the opposite attitude toward larger, national-level interventions like higher carbon taxes....

This Friday (Nov. 25), a rather large partial eclipse of the sun will be on view — but only for a relatively small audience. This will be the fourth time that a new moon will orbit between the sun and Earth to cause a solar eclipse in 2011, just one eclipse shy of the maximum for the number of solar eclipses in a given year. The first eclipse on Jan. 4 coincided with sunrise across Europe....

How receivers learn the values of a and b If the code a x X + b x Y is going to be fixed once and then used for many strings X and Y, then the receiver can learn a and b through the following procedure. In the very first transmission, it is made known to everyone that the messages to be sent will be X = 1 and Y = 0....

In the April issue of Scientific American, I present recent insights into the extraordinary evolution of cichlid fish. Although many factors have probably contributed to the stunning success of this group, one presumably very important one is their unusual feeding apparatus: In addition to the usual mouth jaws that other fish have, cichlids possess an extra set of jaws in their throats—like the creature in the movie Alien. These throat jaws, which are highly modified gill bones, with associated ligaments and muscles, serve as an additional food processer that can crush or pierce food after it passes through the mouth....

Most people imprisoned in Nepal for wildlife crime share two things in common: they did not understand the seriousness of their offense, and they had little conception of how profoundly it would impact not only their lives but also the lives of their families. In interviews with more than 100 people convicted of illegally killing or trapping wildlife, researchers found some lost their businesses and land following their imprisonment. A dozen men’s wives left them....

More than 40 percent of men in the U.S. will show signs of male-pattern baldness sometime between the ages of 18 and 49. But studies looking at the genomes of this group of men have failed to turn up a genetic cause, which makes a true cure seem an unlikely prospect. Treatments for male-pattern baldness, also known as androgenic alopecia, may be forthcoming, however. Recent work is homing in on three types, including one that was reported in March in the journal Science....

By Danny Na and Tom Polansek Animal-nutritionist John Goihl knows Minnesota farmers who feed the remains of dead baby pigs to hogs used for breeding in attempts to ward off infections of a deadly virus in offspring. In Oklahoma, farm workers are mixing manure from swine sick with the disease, known as Porcine Epidemic Diarrhea virus (PEDv), into the food of healthy animals to build their immunity. In Kansas, farmers are spraying a mixture of hog manure containing the virus and water on the noses of pigs to create a “natural vaccine....

Back in 2006, when the vaccine for human papillomavirus (HPV) was introduced, I rushed to get my teenage daughters immunized. Here, amazingly, was a vaccine that could actually prevent cancer. By blocking HPV infection, it protects girls from the leading cause of cervical malignancies. I didn’t give much thought to my son, and neither did the medical establishment. It wasn’t until 2011 that health authorities recommended the vaccine for boys. In hindsight, that delay was a mistake, though perfectly understandable: the vaccine was developed with cervical cancer in mind and initially tested only in girls....

Did you like this article? Editorial Review This article has been reviewed for accuracy, reliability and adherence to academic standards prior to publication. The medieval indulgence was a writ offered by the Church, for money, guaranteeing the remission of sin, and its abuse was the spark that inspired Martin Luther’s 95 Theses. Luther (l. 1483-1546) claimed the sale of indulgences was unbiblical, challenging the authority of the Church and its claim as God’s earthly representative....

Did you like this article? Editorial Review This article has been reviewed for accuracy, reliability and adherence to academic standards prior to publication. The Plague of Justinian (541-542 CE and onwards) is the first fully documented case of bubonic plague in history. It is named for the emperor of the Byzantine Empire at the time, Justinian I (r. 527-565 CE) and recorded by his court historian Procopius (l. 500-565 CE) in his History of the Wars, Book II....

Did you like this article? Editorial Review This article has been reviewed for accuracy, reliability and adherence to academic standards prior to publication. The North African Berber kingdom of Numidia (202-40 BCE) was originally inhabited by a tribe (or federation of tribes) known as the Masaesyli, to the west, and a coalition of smaller tribes, known as the Massylii, to the east. The meaning of these names is unknown but they are thought to be the indigenous terms for the people, not later designations....

Changing the oil in a car every 5,000 kilometers or so seems to be the industry standard (and may well be overkill). But that means a whole lot of pouring and draining motor oil into and out of the U.S. auto fleet: 1.3 billion gallons or so, to be precise. So what happens to all that used oil—and could it be recycled? After all, reusing that lubricant would not only avoid pumping it out of the ground in the first place, thereby delivering a little energy independence from foreign suppliers, it also might help cut climate-altering greenhouse gas emissions....

Lead U.S. climate negotiator Todd Stern said Thursday the Copenhagen Accord represents the best way forward for a binding global climate deal but that success likely rests with a smaller group of major emitters working outside the unwieldy, multi-national United Nations process. In his first public remarks since the conclusion of the United Nations climate talks in December, Stern said the Copenhagen Accord - despite its shortcomings - included “significant breakthroughs in a number of respects....