Recently in Everyday Physics Category

Ars Technica: New technologies are enabling crowdsourcing in a number of scientific disciplines—most recently, seismology. After the 23 August 2011 earthquake on the US East Coast, a video rendering of the seismic waves’ travel was created by plotting the posted Twitter messages that contained the word “earthquake.” Richard Allen, a seismologist at the University of California, Berkeley, has published a paper in Science that discusses the possibilities and the limitations of such crowdsourcing of earthquake information. Besides Twitter, the US Geological Survey seeks the public’s input via its Did You Feel It? website, UC Berkeley has developed an iShake app that makes use of cell phones’ internal accelerometers, and Caltech offers to place seismometers in participants’ homes through its Community Seismic Network project. Crowdsourcing earthquake information is not a new idea: Seismologists have long used first-person reports, particularly for historic quakes that lack high-quality seismographic measurements, writes Scott Johnson for Ars Technica.

Science: Researchers at the Swiss Federal Institute of Technology in Lausanne have been studying the hydrodynamics of wine swirling, done by connoisseurs to release red wine’s bouquet through mixing and oxygenation. They found that three factors determine whether the wine arcs smoothly or starts to splash: the ratio of the level of wine to the diameter of the glass, the ratio of the diameter of the glass to the width of the circular shaking, and the ratio of the centrifugal and gravitational forces acting on the wine. Their findings, which they presented last week at the annual meeting of the American Physical Society's division of fluid dynamics in Baltimore, Maryland, could prove useful not only to wine tasters but also to lab technicians who swirl bacterial cultures to distribute nutrients and remove excess carbon dioxide.

NVP3D: The oldest known mechanism to use clockwork gears, called the Antikythera after the place it was discovered, was found in an ancient Greek shipwreck more than a hundred years ago. The device, of which only 82 badly corroded fragments remain, not only predicted solar eclipses but also organized the calendar in the four-year cycles of the Olympiad, forerunner of the modern Olympic Games. The watchmaker Hublot has now miniaturized the Antikythera from the size of a shoebox to something that you can wear on your wrist. This version also tells the time.

A three-dimensional movie of the mechanism is available at http://nvp3d.com/site/reports/28/antikythera-mechanism.

Bloomberg: Last May, three weeks after undergoing a side-impact test at a National Highway Traffic Safety Administration (NHTSA) facility in Wisconsin, a Chevrolet Volt caught fire in the facility's parking lot. The fire was so severe that vehicles next to the Volt were burned too. General Motors, which makes the electric-powered Volt, and the NHTSA tried but failed to replicate the fire a month later. Now NHTSA is undertaking an investigation of the safety of the lithium-ion batteries that power the Volt and other electric vehicles. Lithium-ion batteries are known to undergo a strongly exothermic reaction if their protective casings are pierced by an object made of steel or other ferrous metal.

Economist: A Fermilab astrophysicist has used his analytical skills to come up with a more efficient way to board planes. Most people are familiar with the usual holdups when boarding: waiting for the person ahead to stow his or her luggage, and having to dislodge seated passengers to get to a center or window seat. Jason Steffen’s method minimizes the former and eliminates the latter. He proposes boarding passengers in all the window seats first, then center, then aisle, starting at the back of the plane and moving forward, and boarding by alternate rows, so passengers are spaced far enough apart to stow their luggage at the same time. In tests conducted by Steffen and Hollywood producer Jon Hotchkiss, Steffen’s method took half the time of the current block boarding method used by most airlines, in which passengers are assigned to groups or zones within the cabin. Now all he has to do is persuade the airlines to adopt it. Steffen has published his findings in the Journal of Air Transport Management.

What the rest of the world knows about the bomb was learned from seismic waves. Tremors registering at 4.52 on the Richter scale suggested that the yield was on the order of a few kilotons.

Three researchers from Ohio State University detect a different unexpected signature however: an atmosphere shockwave spread out from the test site across the planet and high into the ionosphere. Writing in the Bulletin of Atomic Scientists they state that GPS radio waves suffer interference from atmospheric disturbances and by chance the North Korean test occur while they were testing equipment to reduce interference.

By timing when the shockwave from the test hit different GPS stations the three researchers were able to calculate the location of the initial explosion, which matched the seismic data. They suggest that the addition of GPS data to the monitoring stations spread about the world to watch for clandestine nuclear explosions, will strengthen the case for the US to ratify the Comprehensive Test Ban Treaty.

BBC: Benjamin Blankertz and his colleagues at the Berlin Institute for Technology have demonstrated in the lab that it's possible to detect a driver's intention to brake before he or she actually brakes. In their experiment, volunteers drove an arcade-like simulator and were given the task of keeping a fixed distance away from the car in front. A helmet studded with electrodes monitored their brain waves. Whenever the car in front braked, the helmet picked up a telltale signal that heralded the driver's application of the brake pedal 130 milliseconds later. At 113 kilometers (70 miles) per hour, a delay of 130 ms corresponds to a length of 4 meters. If the helmet could be replaced with a more comfortable, less obtrusive device, brain-wave detection could provide a means to shorten stopping distances and avoid accidents, the researchers say.

PhysOrg: Lloyd Smith, an associate professor at Washington State University's School of Mechanical and Materials Engineering, recently investigated three questions of relevance to major league baseball: Can a baseball be hit farther with a corked bat? Is there evidence that the baseball is livelier today than in earlier years? Can storing baseballs in a temperature- or humidity-controlled environment significantly affect home-run production? Smith, working with colleagues from the University of Illinois and Kettering University, tested all three premises at his Sports Science Laboratory on the Pullman campus. "I've got the cool machine that can do the tests," said Smith. He has published descriptions of his experiments and their results in his article "Corked Bats, Juiced Balls, and Humidors: The Physics of Cheating in Baseball" in this month's American Journal of Physics.

Wall Street Journal: A federal law passed in 2007 requires that light bulbs now sold in the US be 25% more efficient than incandescent bulbs. But the very efficiency of LEDs and compact fluorescent bulbs is confusing consumers, reports the Wall Street Journal's Gwendolyn Bounds. A 100-watt incandescent bulb, which most people would regard as bright, emits 1600 lumens of light. That same luminosity can be obtained with a 20-W LED or a 30-W compact fluorescent bulb. Recognizing the potential for confusion, General Electric, Osram Sylvania, and other manufacturers of the new bulbs, have devised new, color-coded labels, but they have not adopted a uniform labeling scheme.

Science: Long thought to be the reason behind Spain’s crippling inflation in the 16th and 17th centuries, the massive amounts of silver shipped in from the Americas may not even have entered Spain’s currency until at least 100 years later, according to a study conducted by a group at the University of Lyon in France and published in the Proceedings of the National Academy of Sciences. Anne-Marie DeSaulty and colleagues used mass spectrometry to measure the ratios of several metal isotopes in 91 old coins from ancient Greece and Rome, medieval Europe, 16th–18th century Spain, and Latin America, writes Sara Reardon for Science. The ratio of the silver-109 isotope to silver-107 was much higher in New World coins than in the European coins. That suggests that even though American silver arrived in Spain in 1550, the Spanish waited well over 100 years before using it for their own currency. DeSaulty believes instead that the Spanish probably used the imported silver for trade. Some people have questioned, however, whether her sample of coins was large enough to support her conclusions and whether the importation of all that silver could have caused the inflation even if it weren’t minted into coins.

San Francisco Chronicle: Last year, San Francisco's Board of Supervisors voted 10–1 to require the manufacturers of cell phones to disclose the level of radiation emitted by their phones. The levels would have appeared next to phones on display in retail outlets. To fight the bill, which never became law, the Cellular Telecommunications and Internet Association sued the city, arguing that the Federal Communications Commission has certified that all phones marketed in the US are safe. Faced with the prospect of both losing the suit and paying the association's legal fees, the city has put the bill on indefinite hold. As the Chronicle's Heather Knight reports, the city will likely enact a weaker version of the original bill.

New Scientist: A new system in San Francisco not only informs drivers of current traffic conditions but also predicts congestion up to 40 minutes into the future. The initiative is a joint project of IBM, the California Department of Transportation, and the California Center for Innovative Transportation (CCIT) at the University of California, Berkeley. The Smarter Traveler Research Initiative combines real-time traffic data with past traffic patterns to predict backups. "The edge of a traffic jam propagates like a shock wave in a fluid," says Alexandre Bayen at CCIT, and thus follows predictable patterns. The Traffic Prediction Tool software draws data from existing “inductive loop” sensors built into roadways and from the GPS on participants’ smartphones to learn their preferred travel times and routes. Drivers can receive e-mails or text messages that apprise them of traffic conditions on their regular commute and recommend alternative routes. Before expanding the service to commuters worldwide, however, the researchers say it needs more work: The software needs to anticipate the problems that could ensue if too many drivers suddenly change their route and create congestion somewhere else.

Science: Current crowd simulations, used to develop safe public spaces, usually treat virtual humans within the model as simple particles that repel each other and zoom to their destinations. While these models are useful for predicting how long pedestrians might take to cross an intersection, they cannot reconstruct or predict the chaotic movement of a large number of people trying to escape a crowded room. Mehdi Moussaid, of the University of Toulouse, France, and colleagues created a computer model that emphasizes human behavior rather than many-body physics. The model doesn’t ignore physical laws, such as the person-to-person energy transfer that help explain “crowd-quakes”, but it does rely on heuristic formulas the team derived from studying patterns of pedestrian movement in videos. Moussaid's approach is the first to accurately reproduce pedestrian behavior across a spectrum of intensity: from lanes of pedestrians formed in simulations of hallway interactions to emergency escapes from bottlenecked rooms.

Nature: Adding iron or cobalt to polyethylene boosts the ubiquitous plastic's propensity to oxidize in sunlight. Bags made from degradable polyethylene duly fall apart, but whether the fragments that remain are environmentally friendly has been an open question. Now, as Nature's Daniel Cressey reports, the UK's Department for Environment, Food, and Rural Affairs (DEFRA) has found that the fragments persist for much longer than the 2–5 years it takes for a bag exposed to the elements to break apart. According to DEFRA, the fragments should not be included in compost lest they ruin it.

Science News: Harvard physicists have described for the first time how flowers generate the forces needed to curl open come springtime, writes Daniel Strain for Science News. In their 21 March article published online in the Proceedings of the National Academy of Sciences, Haiyi Liang and L. Mahadevan studied the asiatic lily and how its petals and sepals—the outer, greener portion of a flower—gradually invert, then peel open like a banana and form a blossom. The Harvard team’s first clue to the mechanism was that the outer margins of petals and sepals ruffled during blooming, while inner surfaces stayed smooth. The researchers also developed a mathematical model to demonstrate how extra edge strain could warp thin materials like flower petals. “Infusing a scientific aesthetic into a thing of beauty only enhances our appreciation of it,” Mahadevan said. “This is what we try to do as scientists.”

Space.com: Many skywatchers enjoyed the so-called supermoon over the weekend. As Tariq Malik reports for Space.com, viewers on Earth witnessed the largest full Moon in more than 18 years. The phenomenon occurred because the Moon was in its full phase and just 50 minutes past perigee—the point of its orbit that brings it closer to Earth. Saturday's full Moon appeared 14% larger and 30% brighter than the smallest full Moons Earth sees. Space.com has posted a beautiful collection of images submitted by readers.

Independent: Scientists say that the magnetic north pole is moving. For two centuries it has been located in Canada, but it is currently relocating toward Russia at a rate of about 40 miles per year. The speed of its movement, having increased by a third in the past decade, has prompted speculation that the field could be about to "flip," which would cause compasses to invert and point south rather than north, something that happens between three and seven times every million years. Geologists believe that the magnetic north pole moves around due to changes in Earth's molten core, which contains liquid iron. Although the shift will affect compasses, it will not affect GPS systems, which rely on satellites.

Institute of Physics: Physicists and mathematicians from the University of Santiago de Compostela in Spain have used mathematical models to show that two languages can coexist in one society. The research, published today in New Journal of Physics (co-owned by the UK's Institute of Physics and the German Physical Society), refutes earlier research that sought to show how one of two languages would inevitably die out. The researchers suggest their work could be used to inform political decisions concerning the protection of endangered languages: "Allowing for varying statuses and interlinguistic similarity could suggest further and more precise political guidelines for protecting endangered tongues, as well as illuminating the evolution of the language entities themselves."

South Bend Tribune: Science cafés, lectures on current science topics held in casual settings like pubs and coffeehouses, have been around for the last decade or so. Although the first cafés originated in Europe, they are starting to pop up in the US, writes Yanan Chen for Indiana's South Bend Tribune. At Hudson's Classic Grill restaurant in Jackson, Michigan, for example, programs begin with a short small-group discussion, then the guest speaker makes a 30-minute presentation, followed by an hour of discussion and questions. "You can drink alcohol while listening to the lecture. It is not in a classroom. Be casual," said Laura Thurlow, biology professor at Jackson Community College and science liaison for the city's science café. Organizers say they are trying to make science more accessible to the general public by presenting informal lectures in a relaxed atmosphere.

Durhamregion.com: Better analysis of bloodstain patterns is the goal of a new project led by Franco Gaspari, a professor at the University of Ontario Institute of Technology in Oshawa. Gaspari and his team recently received a grant from the Canadian government to incorporate fluid dynamics and other physics into the software used by police at the scenes of bloody crimes. According to the Canadian Police Research Centre, Gaspari's project

will foster the development of an important tool that will provide investigators with improved accuracy in crime scene measurements by constructing a more precise re-creation of the crime scene.

Daily Mail: Two PhD students in the UK, Alex Baker and Chris Rose, have produced some amazing photos of Earth, taken with a $70 HD video camera stuck into a Styrofoam box with gaffer tape and floated 23 miles into the atmosphere on a helium balloon. The students, both studying mechanical engineering at the University of Sheffield, wanted to complete their mini-space exploration as cheaply as possible to inspire others to follow suit.

Nature: A Viking legend tells of a glowing "sunstone" that, when held up to the sky, revealed the position of the Sun even on a cloudy day, writes Jo Marchant for Nature. It sounds like magic, but scientists measuring the properties of light in the sky say that polarizing crystals—which function in the same way as the mythical sunstone—could have helped ancient sailors to cross the northern Atlantic. A review of their evidence is published today in Philosophical Transactions of the Royal Society B.

The Independent: On Monday scientists gathered in London at the Royal Society, the UK’s national academy of science, to present their progress on redefining the kilogram. It has been based since 1889 on the mass of a solid cylinder of platinum–iridium alloy locked in a vault in Sèvres, France. The kilogram is the only international standard unit of measurement that is based on a physical object rather than a fundamental physical constant. Scientists now believe, however, that it is time to redefine the kilogram because there is evidence that the precise mass of the international prototype in Sèvres is not as constant as it should be.

Sports Illustrated: Last Saturday at Qwest Field in Seattle, Washington, the Seattle Seahawks beat last year's Super Bowl champions, the New Orleans Saints, 41–30. The upset victory was sealed when running-back Marshawn Lynch evaded several Saints defenders to score a 67-yard touchdown. The touchdown so excited the home crowd that their jumping up and down shook the stadium, causing the Pacific Northwest Seismic Network to register a faint disturbance.

Los Angeles Times: Residents of rural communities in Los Angeles County are fighting to protect their view of the night sky. The county's Department of Regional Planning has been asked to develop a rural lighting zoning ordinance. Possible approaches include shielding lights, turning them toward the ground, and switching them off at a reasonable hour. Lighting has been regulated in other areas, such as Flagstaff, Arizona, for decades. So foreign are the real night skies to Los Angeles residents that in 1994, after the Northridge earthquake jostled Angelenos awake at 4:31am and knocked out most of the power, the Griffith Observatory received many calls asking about "the strange sky they had seen after the earthquake," said Ed Krupp, the observatory's director.

Guardian: Engineers from the UK’s largest defense company, BAE Systems, are using defense technology to help the British Olympic team. Among their successes is a device called Drake that they invented for the sailing team. Drake can model vast amounts of meteorological data by taking and processing readings of the key weather factors, including wind speed and direction and temperature and humidity changes, writes Alok Jha for the Guardian. For the bobsledding team, BAE recruited PhD students to devise a method of customizing each sled for individual athletes. The BAE engineers' next goal is to improve the racing wheelchair used by Paralympians—by using an Airbus wind tunnel to study the wheelchair’s construction and determine the best seating position for different types of races.

New Scientist: A partial eclipse of the Sun will start tomorrow morning on the west coast of Africa and end four hours later in Western China. Observers in northern Sweden will witness the eclipse's greatest extent—86%—at 09:50 local time. The next total eclipse will occur on 13 November 2012 and be visible from Northern Australia and other locations in the southern Pacific.

New Scientist: A compass that doesn't need a magnetic needle? That might sound impossible, but the ancient Chinese worked out how to make one 4500 years ago. An ingenious combination of gears and wheels ensures that a "pointing chariot" features a needle that always points in the same direction. New Scientist includes a how-to video and links to a step-by-step guide, parts list, and kit.

Nature: From collisions in the Large Hadron Collider to marine creatures and the growth of graphene, Nature's Images of the Year provide a colorful slideshow.

New York Times: Which is better for the environment? A real pine tree or an artificial one? John Collins Rudolf takes up the question in his New York Times article. “The natural tree is a better option,” answers Jean-Sébastien Trudel, founder of Ellipsos, a Montreal environmental consulting firm that released an independent study in 2009. The firm found that an artificial tree would have to be reused for more than 20 years to be greener than buying a fresh-cut tree annually, because of such factors as the carcinogens produced during manufacture, the nonrecyclable plastic and metal used in their construction, and the shipping from Asia where most of them are made. Living trees, in contrast, contribute oxygen to the atmosphere while growing and can be composted or mulched after use.

Space.com: Between this evening and tomorrow morning, 20–21 December, astronomers and the general public in North and South America are in for a treat: a total lunar eclipse. A lunar eclipse occurs when Earth lines up directly between the Sun and the Moon, blocking the Sun's rays and casting a shadow on the Moon. As the Moon moves deeper into Earth’s shadow, it changes color from gray to orange or red, because indirect sunlight still passes through Earth’s atmosphere and casts a glow on the Moon. Space.com provides links to a lunar eclipse viewing guide, photos of a total lunar eclipse, a table showing the times of the different states of the eclipse in different time zones, and a star chart.

New Scientist: Researchers in Japan used a new electron microscope, whose beams of electrons have about 40% less energy than those in previous studies, to make measurements of the fragile bonds in carbon atoms on the edge of a sample of graphene. In the past, only high-energy beams were available, which could disturb the bonds on delicate lone atoms. The team could resolve the number of bonds holding the edge carbon atoms in place, which is important because it can affect the graphene sheet’s electrical and chemical properties. Their findings were published in Nature yesterday.

CBS: Frank Kovac, of Monico, Wisconsin, has built the world’s largest rolling, mechanical, globe planetarium—in his backyard. When younger, Kovac had dreams of becoming an astrophysicist, but instead ended up working in a paper mill. Nevertheless, he has spent the past 15 years building the Kovac Planetarium, hand-painting some 5000 stars on its ceiling and installing an electric, variable-speed motor controller to spin the globe itself. Now complete, it is open to the public seven days a week, with an admission charge of $12.

Washington Post: The fluid dynamics of a cat lapping water is the subject of a recent paper in Science. A group led by Roman Stocker, an associate professor of civil and environmental engineering at MIT, conducted the study. Not funded by a grant, the group members proceeded on their own, solely for professional pleasure, prompted by Stocker’s observations of his own cat drinking, which always kept its chin and whiskers dry in the process. While dogs curl their tongue like a ladle to collect water, cats curve their tongue under and touch the liquid lightly with the tip. They then raise their tongue rapidly, sending a mini stream of water up into their mouth, which they then snap shut. “The cat, in effect, balances the forces of gravity against the forces of inertia, and so quenches its thirst,” as Marc Kaufman writes in today’s Washington Post.

Washington Post: The first annual USA Science and Engineering Festival drew a large crowd to Washington, DC, over the weekend. About 1 million people visited the more than 1500 free, interactive exhibits during the grand finale expo on 23–24 October, according to Leslie Tamura of the Washington Post. The expo, hosted by Lockheed Martin, was put together by 850 science organizations, which included professional science and engineering societies, universities, and federal laboratories. In Saturday's well-attended presentation by Dr. Molecule (see image below) of the Bloomfield Science Museum Jerusalem, children participated in experiments that demonstrated chemical reactions and physical forces.

Los Angeles Times: Iridescent, a nonprofit science and discovery center, opened Saturday near downtown Los Angeles. Another studio is set to open in New York next month, and others already operate in the San Francisco area. President and founder Tara Chklovski, who has studied physics and aerospace engineering, started the Iridescent program two and a half years ago to inspire girls and inner-city children to pursue careers in engineering and the sciences. Among the program's backers is the US Navy, which has given a $2.3 million grant "in hopes of 'developing future engineers and scientists' who will be the technological brains behind the military's brawn in years to come," according to Los Angeles Times writer Scott Glover.

New Scientist: Scale is the theme of a recent art exhibit at Measure Gallery 825 in Los Angeles, curated by Harvard physicist Lisa Randall. "I wanted a theme where both art and science could participate and it wasn't just art representing science or science pretending to be art, but where we could think deeply about ideas that underlie both of them," Randall explains. In one of the pieces, “Measurements of Space in a Fractal Structured Vacuum,” artist Felicity Nove created paint pours reminiscent of supernova explosions and black holes on the Hubble website. The exhibit, Measure for Measure, on display 10 September through today, features seven artists and includes paintings, sculpture, and video and installation pieces.

Daily Mail: Recent advances in nanotechnology could turn Willy Wonka’s Three-Course Dinner Chewing Gum into reality. In Roald Dahl’s 1964 novel Charlie and the Chocolate Factory, the gum first tastes like tomato soup, then roast beef and baked potato, and finally blueberry pie and ice cream. Now, food scientist Dave Hart and coworkers at the UK’s Institute of Food Research (IFR) say they have cracked the secret behind creating such a stick of chewing gum. Hart and his team are experimenting with creating different flavor layers separated by a tasteless gelatin, with a final dessert taste at the center, encapsulated in a high-tech gel called Gellan. “Tiny nanostructures within the gum would contain each of the different flavors. These would be broken up and released upon contact with saliva or after a certain amount of chewing,” says Hart.

New York Times: The three-dimensional imaging techniques of the movies are being used to improve athletic performance. Motion capture produces a 3D image on a computer using a combination of advanced sensors, biomechanics, orthopedic research, and animated-film technology such as that used in the film Avatar (2009). The images generated, which can be viewed from any direction, provide a wealth of data regarding limb angles, ball speeds, and g-forces. Some of the innovative uses of the new technology include sports players studying their peak performances to improve their technique and avoid injury, dancers in different locations being able to practice with each other using 3D re-creations, and coaches working remotely with teams by watching them perform drills in three dimensions in another location.

Maryland Gazette: Although the inaugural USA Science and Engineering Festival does not officially begin until 10 October, the Lunch with a Laureate program, which is operating in conjunction with the national festival, has. The lunches take place all over the Virginia, Maryland, and Washington, DC, area. On Tuesday at Maryland’s Bladensburg High School, Nobel Prize winner William Phillips gave a special demonstration involving liquid nitrogen to illustrate concepts involved in his own work with laser light used to slow down and cool atoms. Festival organizers are promising that this month’s festival, which culminates on the National Mall 23–24 October, will be the ultimate multicultural, multigenerational, and multidisciplinary celebration of science in the US.

Scientific American: “Not only is there no epidemiological evidence of a causal connection, but physics shows that it is virtually impossible for cell phones to cause cancer,” writes Scientific American’s Michael Shermer in his article debunking the popular myth. For the same reason that we don’t worry about radios, TVs, microwaves, and power outlets causing cancer—because they don’t emit enough energy to break the molecular bonds inside cells—there’s no reason to fear cell phones either.

Philadelphia Inquirer: One evening last week, Derrick Pitts of the Franklin Institute planted himself and his telescope on the streets of Philadelphia, offering the passing crowd the chance to view the heavens. He was there to gauge interest in the upcoming first annual Philadelphia Science Festival, tentatively slated for 15–28 April 2011. The festival is being billed as a community-wide celebration of science that “will feature lectures, debates, hands-on activities, special exhibitions, and a variety of other informal science education experiences for Philadelphians of all ages.” Apparently, his experiment was a success: About 200 people participated. "People were really jazzed about being able to see this," he said. "Groups of people would stand around and talk about it themselves, and then look again."

New York Times: In December 1942, John Pritchard and two other Coast Guard aviators were listed as missing after their plane lost radio contact—and presumably crashed—during a storm off the southeast coast of Greenland.

Now, 68 years later, the Coast Guard has commissioned a private recovery team to try to locate, excavate and repatriate the three men entombed in a J2F-4 Grumman Duck biplane (see left image) buried in a glacier there. The team set out last month with an arsenal of top-of-the-line technology: ground-penetrating radar, which can detect metallic objects close to the surface; advanced ice-melting equipment, which can pinpoint buried objects as it dissolves the ice around them; a camera that can take pictures from inside deep hollows of ice; and sensors to track the speed the glacier is moving before the plane, and bodies move out to sea.

The Tennessean: Arnold Burger and fellow Fisk University researchers have just made it easier for Homeland Security agents to tell the difference between a dirty bomb and a banana.

Fruit, such as a banana contains potassium, which can give off the same radiation signature as plutonium.

The Fisk researchers, in partnership with Radiation Monitoring Devices Inc, and Lawrence Livermore and Oak Ridge National Laboratories, have developed a cheaper, easy-to-produce, new type of radiation-detecting crystal that is more accurate than most of the devices on the market.

The group has just won an R&D 100 magazine award, given to the 100 cleverest inventions of the year for their work.

Science: A group of French researchers has been studying the “impossible” goal scored by Brazilian soccer player Roberto Carlos during the 3 June 1997 match with France because it is a practical example of the Magnus effect. During the game, standing 35 meters from the net, Carlos kicked the ball markedly to the right of the goal, but in midair, the ball suddenly arced down and to the left, landing just inside the net, ending the match in a tie. The researchers explain the physics of the spinning ball spiral in the New Journal of Physics.

Guardian: The Royal Institution in London is shortening its popular Christmas lecture series, launched in 1825 by Michael Faraday. Instead of five days, the series will span only three days—a cost-cutting measure by the institution. The lectures present scientific subjects for a general audience in an entertaining fashion, and have been broadcast on television since 1966. A video archive of past lectures is available on the RI website.

New Scientist: The latest in computer graphics and animation was on display last week at the SIGGRAPH2010 conference and exhibition in Los Angeles. New Scientist focuses on several of the extraordinary displays at the conference, such as a headset that can make a cookie taste like whatever the wearer chooses through a combination of smell and visual texture.

SPACE.com: On Sunday, thousands gathered on Easter Island to view the total solar eclipse—when the Moon passes between Earth and the Sun, blocking Earth's view of the Sun. This solar eclipse was one of the most remote ever, visible along a thousand-mile track in the southern Pacific Ocean, starting about 2:00pm ET in northern New Zealand and ending about 5:00pm ET at the southern tip of South America. It is the first total eclipse to hit the island in 1400 years.

Physics Today: Curiosity, awareness, initiative, and the fragility of Earth are the themes at the heart of Douglas W. Jacobs’s play R. Buckminster Fuller: The History (and Mystery) of the Universe, which opened last month at Arena Stage in Crystal City, Virginia. The final performance is this weekend.

Listen to a Physics Today interview with Jacobs.

New York Times: Speech recognition software is now capable of handling routine conversations at doctors' offices and basic interrogations at military checkpoints—even in foreign languages. Steve Lohr and John Markoff of the New York Times survey recent progress toward creating artificial intelligence that can interpret and act on human speech.

Physics Today: In Thursday's World Cup match between Denmark and Japan,
Japan's Keisuke Honda curled a free kick over a wall of defenders past
the outstretched hand of Danish goalkeeper Thomas Sorensen and into the
net. Honda's goal demonstrated how soccer players can alter the ball's
trajectory by exploiting the Magnus effect. In the Quick Study in the July
issue of Physics Today, John Eric Goff, a physics professor at Lynchburg
College in Virginia, describes the physics behind bending it like
Honda.

New Scientist: The meter-long plastic trumpet known as the vuvuzela has famously—or infamously, depending on your point of view—become the instrument of choice of 2010 World Cup fans. It was introduced a year ago at a previous soccer tournament held in South Africa, the Confederations Cup. Since then, the vuvuzela has spread among fans like a virus. When hundreds of vuvuzelas are blown simultaneously by football fans, the racket can be deafening. Trevor Cox, president of the UK Institute of Acoustics, explains the science behind the noise.

Science: Airplanes flying through altocumulus clouds can cause localized precipitation. In a paper published by the American Meteorological Society, Andrew Heymsfield of the National Center for Atmospheric Research in Boulder, Colorado, and colleagues explain that for years, aircraft appeared to punch holes in the clouds; now, they realize, the aircraft have been, in effect, seeding the clouds and making it rain.

Try sharing an iPad. It connects you to your physical and intellectual surroundings, rather than alienating you. Assuming your collaborator returns the iPad, you have executed a very different kind of exchange, one that seems oddly democratic and intimate, the same way you might share an album of family photographs. Only now imagine a doctor and patient sharing an MRI, an accountant and client reviewing a balance sheet, a choreographer and dancer discussing a dance notation.

New Scientist: The Royal Bafokeng Stadium in Rustenburg, South Africa, is the site of Saturday's World Cup clash between the US and English soccer teams. At 1500 km above sea level, the Royal Bafokeng is far higher than the stadiums the players usually compete in. In a feature article, Steve Haake and Simon Choppin explore the effect of altitude not only on the players themselves, but also on the flight of the ball.

Nature: Future Attribute Screening Technology (FAST) is an experimental program for assessing airline passengers and others for the intent to cause harm. The program, which is being funded by the US Department of Homeland Security, relies on remote sensors that can measure heart rate, face temperature, and other supposedly outward indications of "malintent." In a news feature, Nature's Sharon Weinberger examines whether these and other methods are effective.

New Scientist: Every two years in Atlanta, the Gathering for Gardner convention draws mathematicians, magicians, and puzzle enthusiasts. This year’s event, G4G9 (the ninth one), was held 24–28 March. The world’s premier celebration of recreational mathematics honors Martin Gardner, who wrote the mathematical games column for Scientific American from 1957 to 1981 as well as numerous books, including The Annotated Alice, first published in 1960. Gardner died on 22 May at the age of 95.

New York Times: Demand in the US for Nissan's small electric car, the Leaf, is so high that customers have already taken up all 19 000 spots on the car's waiting list, six months before the first cars arrive in dealerships. Nissan says it might even suspend pre-orders. Like most small cars on the market, the Leaf has a front-mounted engine that drives the front wheels. The battery-powered electric engine provides up to 80 kW of power (110 hp) and a top speed of 140 km/h (87 mph). The battery holds 24 kWh of energy, which is enough to drive about 160 km (100 miles), and takes 20 hours to fully recharge from a typical power socket installed in US and Japanese houses.

Economist: Fuel cells powered by cheese, though not a new idea, are looking more attractive as an alternative, and greener, energy source. Whey, a byproduct of cheese making, is rich in lactose and, when consumed by bacteria, can produce an electric current. The process is doubly beneficial. Whey is considered an environmental hazard and manufacturers must find a way to safely dispose of it anyway. Another example of recycling cheap raw-waste products as fuel is the use of vegetable cooking oil to power automobiles.

Times Higher Education: The pendulum that Léon Foucault used in his famous demonstration of Earth’s rotation is irreparably broken. Last month, the cable supporting the pendulum’s 28-kg brass bob snapped, causing the bob to crash onto the marble floor of the Museum of Arts and Crafts in Paris.

Physics Today: At a cabinet meeting yesterday, President Barack Obama asked Energy Secretary Steven Chu to help BP contain and mitigate the oil slick spreading from the Deepwater Horizon well in the Gulf of Mexico. Chu will lead a team of government scientists and officials that will meet in Houston for discussions with BP officials.

SiliconValley.com: A group of equipment manufacturers and other interested parties has released a proposal to boost the performance of Wi-Fi by raising its operating frequency from the current 4 GHz to 60 GHz. The proposal from Wireless Gigabit Alliance is among several that tackle the problem of quickly downloading large files.

arXiv blog: Using social networks to make recommendations will always compromise privacy, according to a mathematical proof of the limits of privacy.

Physics Today: Rice University undergraduates Lila Kerr and Lauren Theis have developed a rudimentary blood centrifuge that does not require electricity, by adapting a standard salad spinner.

Various: Updated 4/16/2010: A number of outlets have written articles about the societal impact of volcanic ash caused by this week's eruption in Iceland.

New Scientist: Pure randomness is surprisingly difficult to create, even if you draw on the inherent randomness of quantum mechanics. Now, though, a "true" random number generator is on the cards, by using entangled "qubits."

The Independent: It has been described as probably the most important garden in Europe but is open to the public on only one day a year.

Now, however, the Garden of Cosmic Speculation developed by American-born landscape architect and historian Charles Jencks may be replicated in Geneva at CERN.

Additional photos available at Ficker.

New Scientist: Trying to find remains that have been buried, even animals as large as an elephant or mass graves, is not an easy task. It is made even more difficult when investigators only appear on the scene months or years after such events occur.

One research tool that could potentially help is hyperspectral imaging. This multi-wavelength detector looks for variations in the intensity of light at various wavelengths reflected by vegetation on the ground. The precise pattern of intensities has been found to reflect changes caused by nutrients released into the soil as bodies decompose.

Various: Lightning is typically associated with rain clouds and thunderstorms, which leads to an unusual observation, why is there lightning in the middle of the desert? Or in plumes of volcanic ash?

The answer may lie in a new theory by Thomas Pähtz, Hans J. Herrmann, and Troy Shinbrot, in Nature Physics.

They suggest that particles transfer electrical charge vertically when the particles are smashed together, such that positive charges move downward and negative charges move up in the cloud.

Although the theory explains how the particles develop charge, it doesn't explain the origin of the external electrical field needed to kick off the charging process.

Related links
Why do particle clouds generate electric charges?
Swirling dust shocks physicists NatureNews
Colliding dust grains charge each other up ScienceNews

NYTimes.com: Induction cooking has been around for decades, but only recently has demand driven prices down and selection up. In the last two years, Viking, GE, Samsung and Kenmore have begun selling induction ranges.

With its energy efficiency, kitchen geek appeal and growing reputation for power and precision, induction cooking may be the iPad of the kitchen. Like Apple's latest invention, induction technology could forever change everyday tasks, or it might never deliver on its promise.

NYTimes.com: If you listen to climate scientists—and despite the relentless campaign to discredit their work, you should—says Nobel prize winner Paul Krugman, it is long past time to do something about emissions of carbon dioxide and other greenhouse gases.

Wired UK: This wreck image attached is not computer generated. It's the sonar image of Russian nuclear submarine B-159 (called K-159 before decommissioning), which has been lying 248 meters down in the Barents Sea, between Norway and Russia, since 2003. The Russian Federation hired Adus, a Scottish company that specializes in high-resolution sonar surveying, to evaluate if it would be possible to recover the wreck.

Nature News: The reasons for the current financial crisis have been picked over endlessly, but one widespread view is that it involved failures in risk management. Facing up to these failures could prompt the bleak conclusion that trying to anticipate the economic future is an impossible task. That's the position taken by Nassim Nicholas Taleb in his influential book The Black Swan, which argues that big disruptions in the economy can never be foreseen, and are much more common than is evident from conventional theory.

How should those still working in financial markets absorb this pessimistic message? In a preprint on arXiv, Andrew Lo and Mark Mueller of the Sloan School of Management at MIT, in Cambridge, suggest that what economists grappling with uncertainty need is a proper taxonomy of risk. In this way, they state, risk assessment in economics can be united with the way uncertainties are handled in the natural sciences. It may then become clearer where conventional economic theory is a reliable guide to planning and forecasting, and where its predictive value fails.

NYTimes.com: Eureka Fund, based in San Francisco, is one of a handful of new nonprofit organizations created to give the general public an opportunity to pay for scientific research that is not fully supported by government or private sources.

They are part of a fledgling movement to take the idea of crowd-sourcing and crowd-financing, which has worked in arenas like small business and education, to scientific research.

And while the notion of citizens’ directly donating to public research that could ultimately produce profits may raise questions, several ventures are entering the field. Two other websites—Sciflies.org, based in St. Petersburg, Florida, and FundScience.org, in Pittsburgh—plan to roll out their donation platforms to finance independent research by this summer.

Chemistry World: Researchers in the US have shown that perovskites—a class of mixed oxide minerals—can perform as well as platinum in certain types of catalytic converter for removing pollutants from diesel exhaust. Although it is early days in the research, the finding could eventually result in cheaper, more robust catalytic converters for diesel engines that do not rely on expensive and scarce platinum group metals.

Related link
Strontium-doped perovskites rival platinum catalysts for treating nox in simulated diesel exhaust

NPR: At the American Chemical Society meeting in San Francisco last week, scientists presented work on everything from the greenhouse gas emissions of livestock to the effect of human skin oils on office air quality. Ira Flatow and guests discussed these stories and other news from the meeting on Science Friday.

Wall Street Journal: Bill Watkins, the former CEO of hard-disk drive maker Seagate Technology, wants to shake up the prices of solid-state light-emitting diodes.

Watkins became CEO of LED maker Bridgelux in January. On Tuesday, the Sunnyvale, California, company released a product called Helieon that Mr. Watkins says will cost as low as $20 for a lighting unit that has a lifespan of more than 10 years.

While $20 may seem like a lot for a lightbulb, Mr. Watkins says the price is less than half of the $50 that has been standard for similar LED lighting systems.

Physics Today: A new radiocarbon dating technique that can determine the age of ancient mummies, old artwork, and other relics without causing damage was announced yesterday at the annual meeting of the American Chemical Society held in San Francisco, California.

"This technique stands to revolutionize radiocarbon dating," said Marvin Rowe, of Texas A&M university at Qatar, who led the research team. "It expands the possibility for analyzing extensive museum collections that have previously been off limits because of their rarity or intrinsic value and the destructive nature of the current method of radiocarbon dating."

Physics Today: Two decades of atomic bomb testing in the atmosphere are yielding an unexpected bonus for wine merchants concerned about fake vintages.

Graham Jones from the University of Adelaide, Australia and colleagues reported yesterday at the American Chemical Society (ACS) annual meeting in San Francisco, California, a new radioactive carbon test to determine whether that Bordeaux or burgundy is from a fine vintage year and commands premium price or actually is a counterfeit wine worth much less.

Fake wine is "an ongoing problem," says Jones, with some wine experts estimating that up to 5 percent of the fine wine sold today is fake.

"The problem goes beyond ordinary consumers being overcharged for a bottle of expensive wine of a famous winery with a great year listed on the label," Jones pointed out. "Connoisseurs collect vintage wines and prices have soared with 'investment wines' selling for hundreds of thousands of dollars a case at auction."

Jones said the wine industry is fighting forgeries with special seals and high-tech labels. The method for authentication of a wine's vintage may provide added confidence that the vintage on the label is the vintage in the bottle.

A 'hot' grape

The new vintage-checking technique is similar to radio-carbon dating, used for years to estimate the age of objects up to 68,000 years in the past. It works by comparing the amount of carbon-14 (C¹⁴), a less common form of atmospheric carbon, to carbon-12 (C¹²), which is more stable and abundant.

The ratio of these two carbon forms, or isotopes, has remained constant in the atmosphere for thousands of years.

"Until the late 1940's all carbon-14 in the Earth's biosphere was produced by the interaction between cosmic rays and nitrogen in the upper atmosphere," Jones says. "This changed in the late 1940's up to 1963 when atmospheric atomic explosions significantly increased the amount of C¹⁴ in the atmosphere. When the tests stopped in 1963 a clock was set ticking—that of the dilution of this "bomb-pulse" C¹⁴ by CO₂ formed by the burning of fossil fuels."

Traces of radioactive carbon—including with recent vintages the "bomb-pulse"—are captured by the grape plants through the absorption of carbon dioxide and eventually transformed into alcohol and other carbon-based components of the wine.

"The year that the grapes were grown fixes the age or vintage of the wine," Jones says.

"The carbon-14 isotope ratio of the wine alcohol can therefore be used to determine the vintage of a wine."

An accelerator mass spectrometer was used to determine the C¹⁴ levels in the alcohol components of 20 Australian red wines with vintages from 1958 to 1997 and the measurements compared to the radioactivity levels of known atmospheric samples. They found that the method could reliably determine the vintage of wines to within the vintage year.

In addition to testing alcohol, measuring the age of other wine components, such as tartaric acid and various phenolic substances, can help improve the reliability of the technique for detecting fraud, Jones notes.

Paul Guinnessy

Related link
How atom bomb tests could help detect wine fraud The Guardian
Carbon-dating wine can spot fake vintages: research The Daily Telegraph

Science: Pipes feature strongly in the infrastructure of everyday life, from domestic water pipes to oil and natural gas conduits. A primary consequence of the onset of turbulence in the fluid flowing through the pipes is the dramatically increased power required to pump stuff at the same rate. Thus, the incentives to understand and control the transition process are strong.

More than 100 years after Osborne Reynolds's seminal experiments on the transition of flow through a pipe from a laminar (smooth) to a turbulent state, the exact physical mechanism that drives this phenomenon still vexes the fluid mechanics community.

In Science Björn Hof and associates describe a mechanism that feeds energy into a turbulent flow system, allowing the onset of the transition to be manipulated and even the suppression of the turbulence.

Related link
Eliminating turbulence in spatially intermittent flows

washingtonpost.com: March Madness—the annual NCAA basketball playoff spectacle—begins in earnest this week.

The Washington Post takes a look at research started by Peter Brancazio, a former physics professor at Brooklyn College, who in the 1980s wrote a book on the physics of sport and how to optimize scoring.

In basketball, the ball typically follows a parabola—it's the elegant arched trajectory naturally formed by any projectile, from an artillery round to a tomato, moving in a gravitational field.

According to Brancazio, the correct angle for scoring from free throws is to create a parabola curve by angling the throw at 45°, except when it isn't, which is most of the time.

The reason is that 45° works only if the ball is shot as the same height as the basket. Those of us who aren't 7 ft tall with long arms have to compensate by launching the ball at a higher angle, typically in ranges from 52° to 59°.

More recent computer simulations suggest 52° is the optimal angle to score in most basketball games.

Related Link
Analyzing effects of hoops ball hog InsideScience News

Sciencebase: Back in the 1970s LP's were the common medium of choice for Hi-fi enthusiasts. When the compact disc emerged on to the market with its claims of superior quality and scratch resistance, the hi-fi enthusiasts split into two camps: those who clung to vinyl and those who went digital.

But, was concentrating on audio quality all for nothing? Within another generation the notion of digital audio had changed with compressed formats such as MP3's becoming popular.

Jerald Hughes of University of Texas Pan American in Edinburg writing in the International Journal Services and Standards has a nice table showing the technical specification of the human ear and comparing it to the various analogue formats. It turns out that if you want the best quality, LP's are not the way to go, an older format reel-to-reel better matches to the audio range of the human ear.

Related Link
Int. J. Services and Standards, 5 (4), 333-353

The Economist: Eskimos have numerous ways to describe different types of snow, whether its 'sticky,' flakey, wet, or dry. And as the recent snowstorms on the East coast of the US have shown, the type of snow that falls on the ground (heavy and wet with the first snowstorm, leading to power outages, felled trees, and blocked roads for days, and light and fluffy for the second, which caused less disruption) can have a big impact on whether utilities and governments can still provide core services.

Forecasting what sort of snow will fall is not easy. But Jim Steenburgh and Trevor Alcott from the University of Utah think they have found a correlation between weather conditions at the time of a snowfall and the amount of water in the snow that fell.

This is called the snow-to-liquid ratio (based on the area of snow cover and how much liquid it would produce when melted), and the higher the ratio, the drier and more powdery the snow.

Steenburgh and Alcott found that temperature plays a large part in controlling snow density. Where that temperature pertains, though, is crucial. It is the temperature above the crests of the range, where the snow crystals form, that seems to matter most. When this is around freezing point, the snow formed is dense (ie, the value of the ratio is low). As the temperature falls, snow gets drier and fluffier because of the formation of dendrite crystals that contain lots of spaces. As conditions get colder still, though, the crystals become more compact again, and the snow gets heavier.

Nature News: Google's search engine is a powerful tool for helping scientists to find academic papers and details of conferences or identify potential collaborators. And for most researchers around the world, access to Google—and all its related products, including the literature search Google Scholar—is unfettered.

Despite some google results being censored by the Chinese government, the tool is widely used in China.

So Google's move to withdraw from the Chinese market after a series of hacking attempts on its servers, may have an unintended impact on access to the latest scientific research papers by Chinese scientists. Alternately, it may strengthen use of more specialized search engine products produced by scientific publishers who offer access to China at a free or discounted rate.

Related Physics Today article
Physics in China

New Scientist: Using crime data from southern California, Jeffrey Brantingham of the University of California, Los Angeles, and his colleagues set out to calculate how the movements of criminals and victims create opportunities for crime, and how police can reduce it. They came up with a pair of equations that could explain how local crime hotspots form—which turned out to be similar to those that describe molecular reactions and diffusion.

NPR: A new study used cell phone billing data for 50,00 people in a European country to show that people's travel patterns are extremely predictable. That's true for both homebodies and jet setters. Regardless of age, language group, and so forth, people's movements were predictable 93% of the time. The study shows the emerging power of using cell phone data for social science research.

The Daily Telegraph: The Sun follows an 11-year cycle in which its radiation output and sunspot activity waxes and wanes. Currently the Sun is at its minimum radiation output.

A new report in the UK suggests that as the Sun's output rises to a new maximum, satellite navigation devices will be susceptible from the expected increase in solar flares.

The bursts of radiation caused by the flares interfere with signals from satellites orbiting Earth, causing receivers to fail and lose track of their position.

Nature News: The burning of fossil fuels such as coal and oil releases carbon dioxide that alters the balance of carbon isotopes naturally found in the environment—an effect that is now being found in food, reveals a US study.

Science News: Once Martian sand grains hop, they don’t stop.

That’s the conclusion of a new aeolian study that finds sand can move on Mars without much windy encouragement.

Related link
Difference in the wind speeds required for initiation versus continuation of sand transport on Mars: Implications for dunes and dust storms

Related story
Dunes on Mars: How sand shifts without wind NPR

NPR: Determining what is real and what is fake has long been a problem for art curators. It is estimated that 20% of the worldwide art market is made up of forgeries. But art lover and Dartmouth College mathematics department chairman Daniel Rockmore has developed a technique that is helping to determine the difference between excellent copy and the real McCoy.

NYTimes.com: The America’s Cup has always been a showcase for innovation: The 1895 victor, Defender, for example, used aluminum, steel, and bronze in the hull, an unheard–of combination at the time. And sailing in general, and high-level racing in particular, are no strangers to technology. But it has not been used at such an extreme scale before.

The most obvious advance can be seen rising above USA-17, which is owned by Lawrence J. Ellison, president of the software company Oracle. It looks as if someone wrenched a wing off a large jetliner and perched it, tip up, atop a trailer hitch on the boat’s middle hull.

Related Physics Today articles
The physics of sailing February 2008
Sailing and the physics of lift (letters about the previous article) September 2008
Ship hydrodynamics June 1978

ScienceNOW: Have you ever noticed that the first gunslinger to draw his gun in a movie is invariably the one to get shot?

Nobel prize–winning physicist Niels Bohr did, once arranging mock duels to test the validity of this cinematic curiosity.

Following Bohr's example, researchers have now confirmed that people move faster if they are reacting to another person's movements than if they are taking the lead themselves.

NYTimes.com: Freestyle aerialists, skiers that hurtle off a curved ramp at 30 miles per hour, soaring six stories in the air while doing three back flips and up to five body twists, are not actually throwing caution to the winds. It is not fate that plops them down at the end of their jumps, more or less upright and safe, in a cloud of powdery snow. It is physics, and plenty of preparation.

"The forces are pretty simple," said Adam Johnston, a physics professor at Weber State University in Ogden, Utah.

"There's the force of the ramp on his skis, and the force of gravity on him," Johnston said, after Ryan St. Onge, the reigning world champion in men's aerials, zipped down a steep inrun, leaned back as he entered the curved ramp until he was nearly horizontal, and flew off at a 70-degree angle.

But it is enough to create torque that sends St. Onge somersaulting backward as he takes to the air, arcing toward a landing on a steep downslope that the skiers and coaches have chopped and fluffed for safety.

"Once he's in the air, the only force on him is gravity," Johnston said. "You could trace his center of mass as a perfect parabola through the whole thing. From the physics point of view, that's one of the beautiful things."

NPR: Airlines are paying extra attention to the weather these days: the weather in space.

That's because more commercial flights are using shortcuts that take them near the North Pole or the South Pole. And in polar regions, flights are vulnerable to cosmic storms that can interfere with communication and navigation systems, or even expose travelers to doses of radiation above usual safety levels.

guardian.co.uk: Says Dylan Evans:

The UK terror threat has been raised from "substantial" to "severe"—but what on earth does this actually mean?

The official explanation—that an attack is now "highly likely" rather than merely "a strong possibility"—does not make things any clearer.

Given that the threat level had stood at substantial since last July until this weekend's announcement, and there were no terrorist attacks during this period, we can infer that "a strong possibility" indicates an attack has a probability of less than 1% per day. But how much greater is the probability now that an attack is "highly likely"? Would it be 2% per day, or 5%?

The obvious solution to this problem is to dispense with verbal labels entirely, and to express risk estimates in numerical terms. This is not a new idea; more than a century ago, William Ernest Cooke, government astronomer for Western Australia, argued that weather forecasters should attach numerical probabilities to their predictions.

The idea is often rejected, however, on the grounds that it would be too complicated for most people to understand. This is rubbish. US National Weather Service forecasters have been expressing their forecasts of rain in numerical terms since 1965, and over the years they have got better and better at it. If weather forecasters can do it, why not the rest of us?

Various: The formula for the perfect parking job was recently worked out by mathematician Simon Blackburn at the University of London.

"In November 2009, Vauxhall Motors commissioned me to write a report on some of the mathematics of parking," said Blackburn. "It was a great opportunity to describe how 'school' mathematics can be used to understand a question that lots of people might ask, and I thoroughly enjoyed writing the report."

Stanford mathematics professor Keith Devlin tells NPR's Audie Cornish, "it's actually a very clever use of simple mathematics."

Related links
The formula for perfect parallel parking NPR
The geometry of perfect parking

Science News: A stone hitting a pond can produce a tiny supersonic splash, a new study has found.

Researchers studying the shape of an air cavity made when an object hits a liquid noticed a similarity to the shape of the nozzles that are in supersonic jet engines. Sure enough, air escaping from the cavity can reach supersonic speeds, the team reports in a paper published online 11 January in Physical Review Letters.

Related news story
Supersonic bathtub physics: What happens when discs are pushed through water, Scientific American

Various: As more aftershocks hit Haiti this morning after last week's earthquake, scientists have been trying to assess what further damage the country may suffer.

David Kerridge, who is head of Earth hazards at the British Geological Survey (BGS), says that "with an earthquake of this size and the mountainous terrain there is a strong possibility of landslides which may have caused many causalities in more remote parts of the island. Due to disruptions in communications the full extent of the disaster might not be clear for a few days."

Kristina Bartlett Brody of ScienceNews has talked to David Applegate, senior science adviser for natural hazards with the US Geological Survey. "Our folks and others are acquiring all the imagery they can," he says, "in order to examine possible landslide-dammed drainages that could create subsequent flash flood hazard, identify surface rupture and look for the extent of ... ground failure."

Haiti's political situation had made it a difficult place to do science, says Eric Calais, a geophysicist at Purdue University in West Lafayette, Indiana, who has used GPS stations to monitor the area since 2003 (see left). "A lot of researchers who otherwise would have liked to work in Haiti decided not to.... There is very little science infrastructure."

Aftershocks

But while scientists, particularly those who work in the region, try and collect their instruments, Haiti has suffered more than 50 aftershocks measuring more than magnitude 4.5 which have hampered both relief work and in the ability of researchers to get to their instruments. The largest aftershock, a 6.1-magnitude tremor, struck southwest of Port-au-Prince at 6:03 EST this morning.

Brian Baptie, also from BGS says that "earthquakes of this size always have aftershocks that can last for many weeks" which may hamper rescue efforts and cause buildings to collapse that were affect by the original seismic event.

Nevertheless, some conclusions can be drawn from the existing data—based on GPS readings Calais has created a simulation showing how the ground has deformed since the earthquake (see below).

Simulation of coseismic ground motion based on the finite fault model of USGS/NEIC (shows on the surface projection of the rupture, which dips 70 degrees to the south). Black arrows show expected displacements at GPS sites, background color shows interferometric fringes (ASAR IS2 ascending, 2.82 cm range change between fringes).

Was the quake predictable?

Paul Mann (see right image) from the University of Texas at Austin's Jackson School of Geosciences has explained in more detail how he and his colleagues back in 2008 forecasted that Haiti was going to suffer a severe earthquake in the near term.

"Earthquake prediction to a seismologist means that the epicentral location, date and size of the event can be determined before the earthquake occurs on faults that may have been quiescent for years or even centuries," he says.

"In our Haiti studies, we estimated the size of the future event (7.2 magnitude on the Ritchter scale) based on the time we inferred since the fault was last active [the last major earthquake was in 1751], the rate of slip along the fault as determined from GPS measurements in Haiti published by D. M. Manaker et al. (2008) (7 mm/yr), and the location of the rupture (the Enriquillo-Plantain Garden fault zone (EPGFZ), a strike-slip fault we have studied from geologic mapping)."

"All attempts to precisely predict the exact date of a major earthquakes on the many plate boundaries and seismically active intraplate areas on the planet have ended in failure," he says. But attempts "to forecast the likely sites of future earthquakes based on GPS studies and fault mapping have been more successful since they are less specific (ie, no certain date or epicentral locations)."

Mann and his group calculated that if the ground is moving at 7 mm per year, and the last major earthquake happened 250 years ago, then there is an accumulated strain of 1.7 meters (7 mm X 250 yrs = 1.7 meters). Other regions that have had ground displacement of a similar amount have had earthquakes of 7.0-magnitude, which led to their prediction of a 7.0-magnitude earthquake for Haiti. Last week's earthquake was exactly a 7.0 magnitude earthquake.

Mann and his colleagues were particularly worried about the large population situated on the fault line—the city of Port-au-Prince has a population of 2 million people. The city is well known for poor construction, and the surrounding area has many steep hills of loose soil that have been built on. In an earthquake this soil could buckle and quickly undermine the buildings' foundations.

It was for these reasons, says Mann, that they presented their warning to geologists and policy makers at the 2008 Caribbean conference. It wasn't a prediction, he adds, but a forecast, "similar to the way this term is used by meteorologists," he says, "who forecast future weather trends but cannot predict exact weather conditions on specific dates weeks or months into the future."

The next big one?

The research that Mann and his colleagues have done in the region suggests that the next big earthquake could be along the Septentrional fault zone of the northern Dominican Republic.

"This second, northern strand of the Carib-Noam plate boundary has a faster rate than the Enriquillo-Plantain Garden fault zone and therefore accumulates strain at a faster rate," says Mann. According to their calculations, although there hasn't been a major quake for 800 years along the fault, they forecast that a 7.5 magnitude earthquake is likely sometime in the future. "We have no idea when this fault might rupture: tomorrow or 100 yrs from now," Mann says, "but recent events show the importance of this type of research, and retrofitting older buildings in order to avoid a repetition of the Haiti disaster along that part of the plate boundary."

Related Links
After Haiti, worries about other big quakes InsideScienceNews
Geologists to evaluate future Haiti risks Naturenews
Interseismic Plate coupling and strain partitioning in the Northeastern Caribbean
Actively evolving microplate formation by oblique collision and sideways motion along strike-slip faults: An example from the northeastern Caribbean plate margin (1995)
Powerpoint presentation delivered by Mann et al. at 18th Caribbean Geological Conference (2008) (138MB PPT)
Paleoseismicity of the North American-Caribbean plate boundary (Septentrional fault), Dominican Repulbic (1993)

The Independent: The Royal Society in London is making available in digital form the key original manuscript that describes how Isaac Newton devised his theory of gravity after witnessing an apple falling from a tree in his mother's garden in Lincolnshire, although there is no evidence to suggest that it hit him on the head.

washingtonpost.com: This year marks the 50th anniversary of the creation of the laser. Like many a transformative development, it was met initially with thunderous public indifference. A number of techno-pundits regarded the upstart gizmo as basically a glorified parlor trick, a "solution looking for a problem," as Charles Townes, who won the Nobel Prize for pioneering the idea, later wrote.

Half a century later, lasers check out our groceries, read and write CDs and DVDs, guide commercial aircraft, enable eye surgery and dental repairs, target weapons, provide worldwide communications, survey the planet, print documents, cut fabric for clothing and metal for tools, make powerful pointers for PowerPoint slides and are now poised to ignite nuclear fusion, among scores of other uses.

Related news story
The laser turns 50: A birthday bash NPR

Science: Back in the late 1990s, archaeologist Sam Paley of the University at Buffalo in New York was frustrated in his study of the throne room of the 9th century BCE Northwest Palace at Nimrud, the storied Assyrian capital in what is now Iraq, as many artifacts from the room were scattered among many museums.

Then at a conference he heard a presentation by Donald Sanders, a leading proponent of using interactive three-dimensional computer graphics in archaeology, and enlisted Sanders's help.

The pair spent many years getting photographs from museums and successfully built a virtual 3D model of the structure.

The throne room is a classic example of the growth of virtual archaeology, in which archaeologists use computers to re-create the environment and conditions of the past.

The technique is slowly moving into mainstream archaeology.

WSJ.com: Almost since Pope Gregory XIII promulgated the new calendar—itself a reform of Julius Caesar's calendar—in 1582, proposals have bubbled up for something better.

Creating a calendar is difficult. Western tradition demands a seven-day week. Ancient custom, rooted in Moon cycles, calls for a 12-month year. The Earth's tilted axis produces four seasons. But Earth's orbit, uncooperatively, takes slightly more than 365 days, and 365 is divisible by none of 7, 12 or 4. And thanks to the little bit of extra time—about one-fourth of a day—required for a complete orbit, leap years are needed to keep things on track.

The Wall Street Journal's Charles Forelle takes a brief look at the Gregorian calendar and some of the alternatives such as giving February, May, August, and November 35 days and the rest 28 days, except in a leap year, when December has 35.

NPR: One of the more dramatic changes we've heard in music over the last 10 years is that it seems to have gotten louder.

The reason is compression, the dynamic compression that's used a lot in popular music. The idea is to make a song jump out of your iPod compared with the song that preceded it.

However, the technique can make listening to music fatiguing as well as distort the sound of the instruments.

This issue came to a head last year with the release of Metallica's album Death Magnetic.

That record is so loud that the International Telecommunication Union has set standardization measurements for long-term loudness, says Bob Ludwig, a record mastering engineer. "And that Metallica record is one of the loudest records ever produced."

NYTimes.com: During the holiday season, many people place toy trains on circular tracks beneath their Christmas trees.

Last month, at the Princeton Plasma Physics Laboratory, physicists and engineers built tracks inside one of its fusion reactors and ran a toy train on them for three days.

It was not an exercise in silliness, but in calibration.

The modified model of a diesel train engine was carrying a small chunk of californium-252, a radioactive element that spews neutrons as it falls apart.

“We needed to refine the calibration technique to make sure we are measuring our neutrons as accurately as possible,” said Masa Ono, the project head of the National Spherical Torus Experiment.

NPR: During the holiday season we see images of lots of geometrically incorrect snowflakes.

Chemist Thomas Koop thinks ice crystals are masterpieces of natural beauty. Unfortunately, he says, "This beauty is sometimes corrupted."

Koop, a professor at Bielefeld University in Germany, says the problem is that many of these images show ice crystals with five or eight sides. In other words, he says, they are scientific abominations.

Related news story
Christmas card snowflakes 'corrupt nature' by defying laws of physics

Nature News: The first analysis of emissions from commercial airline flights shows that they are responsible for 4–8% of surface global warming since surface air temperature records began in 1850—equivalent to a temperature increase of 0.03–0.06 °C overall.

The analysis, by atmospheric scientists at Stanford University in Palo Alto, California, also shows that in the Arctic, aircraft vapor trails produced 15–20% of warming.

guardian.co.uk: From Leonardo da Vinci to Le Corbusier, the golden ratio is believed to have guided artists and architects over the centuries.

Leonardo is thought to have used the golden ratio, a geometric proportion regarded as the key to creating aesthetically pleasing art, when painting the Mona Lisa.

Now a US academic believes he has discovered the reason why it pleases the eye.

According to Adrian Bejan, professor of mechanical engineering at Duke University in Durham, North Carolina, the human eye is capable of interpreting an image featuring the golden ratio faster than any other.

Popular Science: Everyone knows light exposes film, but other forms of radiation do as well—a fact you can use to take pictures in some pretty unusual ways.

It's also how radioactivity was first discovered. In 1896, French physicist Henri Becquerel stored some x-ray film in a drawer along with a uranium rock which, he found after developing the film, had exposed the film.

It's not hard to repeat Becquerel's experience at home with standard film. Theodore Gray at Popular Science explains how with Fujifilm ISO 3000 instant film.

ScienceNOW: Nitrogen atoms are needed to make many important chemicals from drugs to fertilizers.

But getting those atoms into chemicals is challenging, because nitrogen molecules are tough nuts to crack.

They consist of two atoms sharing a stubborn triple bond, which chemists can break up only by scorching them with temperatures of up to 500 °C. And that results in the simple chemical ammonia, which needs further processing to produce more complicated compounds.

Now chemists have bypassed the energy-intensive reaction and devised a new one that splits molecular nitrogen at room temperature and synthesizes a common fertilizer.

Wired.com: Inspired by videos of renowned hacker Johnny Chung Lee who turned the $40 Nintendo Wiimote remote controller into a finger-tracking device and a touchscreen white board, physicist Rolf Hut of Delft University of Technology in the Netherlands has built a Wiimote wind sensor.

"It was just a bendy pole with an empty bottle on top with an LED light on the bottle," Hut said. "And it swayed in the wind."

The Wiimote can track just about anything: All that's needed is an LED light. Hydrologist Willem Luxemburg, also from Delft University of Technology demonstrated a hacked water-level sensor made from a Wiimote and a plastic boat at the meeting of the American Geophysical Union in San Francisco.

Nature: Discussion needs to be open about how exploitation of Earth's internal heat can produce earthquakes, says Domenico Giardini, so that the alternative-energy technology can be properly utilized.

NYTimes.com: It is not easy to reinvent the wheel, but researchers at the Massachusetts Institute of Technology are giving it their best shot.

The Senseable City Laboratory at MIT has designed a wheel called the Copenhagen Wheel that captures the kinetic energy released when a rider brakes and saves it for when the rider needs a boost.

The Copenhagen Wheel was unveiled yesterday at the COP15 United Nations Climate Conference.

Wired.com: A team of US Geological Survey scientists have developed a web service that combines seismic data about an earthquake with tweets of surprise and angst from the popular microblogging service's users.

The goal of the project is to improve emergency response by providing a crowd-sourced window of the conditions on the ground immediately following a quake.

NYTimes.com: In a speech given just a few weeks before he was lost at sea off the California coast in January 2007, Jim Gray, a database software pioneer and a Microsoft researcher, sketched out an argument that computing was fundamentally transforming the practice of science.

Gray called the shift a "fourth paradigm." The first three paradigms were experimental, theoretical, and, more recently, computational science. He explained this paradigm as an evolving era in which an "exaflood" of observational data was threatening to overwhelm scientists. The only way to cope with it, he argued, was a new generation of scientific computing tools to manage, visualize, and analyze the data flood.

New Scientist: Stephen Wolfram reckons he can model the entire universe using tiny computer programs. But despite being the creator of a "search engine" that provides answers, he still has to convince his peers that he's on the right track, as David Cohen discovers.

NPR: Three former MIT students who formed their own company called Levant Power have developed a shock absorber for cars that takes the energy generated from bumps in the road and sends it to the drive train.

The prototype, called GenShock, along with computer simulations developed at the company, indicate that a heavy vehicle can save about 3% in fuel costs using the GenShock system.

The Economist: Airlines could take a more naturalistic approach to cutting jet-fuel use, and it would not require them to buy new aircraft.

The answer, says Ilan Kroo and colleagues at Stanford University, lies with birds. Since 1914, scientists have known that birds flying in formation—a V-shape, echelon, or otherwise—expend less energy.

Photo credit: John Avise, University of California, Irvine

The air flowing over a bird’s wings curls upwards behind the wingtips, a phenomenon known as upwash. Other birds flying in the upwash experience reduced drag, and spend less energy propelling themselves.

When applied to aircraft, the principles are not substantially different.

Kroo and his team modeled what would happen if three passenger jets departing from Los Angeles, San Francisco, and Las Vegas, and all traveling to London, were to rendezvous over Utah and assume an inverted V-formation.

They found that the aircraft consumed as much as 15% less fuel. Nitrogen-oxide emissions during the cruising portions of the flight fell by around a quarter.

NYTimes.com: In a finding that is sure to add to one of the longest-running debates in music, a detailed analysis of the varnish on five instruments made by Antonio Stradivari reveals that he coated the wood with a rather humdrum mix of oil and resin. Those looking to the varnish as the secret to the master Italian violin maker’s renown, the study suggests, had best look elsewhere.

Macworld: If you are in need of finding out if there is ammonia, chlorine gas or methane in the air around you, there's an iPhone app for that.

A researcher at NASA's Ames Research Center has developed what NASA calls a proof of concept of new technology that would bring compact, low-cost, low-power, high-speed nanosensor-based chemical sensing capabilities to cell phones.

Nature: The mechanisms that govern the rate at which glasses soften on heating have long been a mystery. The finding that colloids can mimic the full range of glass-softening behaviors offers a fresh take on the problem.

Related Link
Soft colloids make strong glasses