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News Picks

Physics Today’s online staff summarize the most important and interesting news about science from the world's top media outlets.

There are 74 posts for the selected month (January 2015).
January 30, 2015 4:35 PM

ESA must wait for comet probe Philae to wake up

BBC: Launched more than 10 years ago, the European Space Agency’s Rosetta spacecraft reached comet 67P/Churyumov–Gerasimenko last August. On 12 November, Rosetta’s robotic lander Philae touched down on the comet’s surface after having bounced twice. Thanks to its primary battery, it was able to transmit about 60 hours’ worth of data before it exhausted its power supply. However, Philae’s exact location has not yet been determined, and it has not received enough sunlight to recharge its secondary battery. ESA controllers hope that as the comet moves closer to the Sun over the next few months, Philae will be able to reboot itself and resume its communications with Rosetta.
January 30, 2015 12:00 AM

Credit card transactions are enough to identify card holders

Nature: Metadata collected from credit card transactions has provided much useful information to researchers, businesses, and others interested in consumer spending, economic trends, and so forth. To protect the card holders’ identities, their name, address, credit card number, and other information directly linked to them are deleted. However, according to a study published in Science, even without that information, card holders can still be identified. The researchers looked at three months of credit card records for some 1 million people and were able to identify 90% of them just by knowing the date and location of four of their transactions. Although complete anonymity may be impossible in this modern age, progress is being made in creating legislation to protect consumers.
January 29, 2015 2:50 PM

Monitoring global ice loss with hydroacoustics

BBC: Different types of icebergs make different sounds as they break away from glaciers, according to a study published in Geophysical Research Letters. Oskar Glowacki of the Polish Academy of Sciences and colleagues placed underwater microphones in the ocean and listened to the rumbles, groans, and snaps emitted as ice calved off the Hans Glacier in Svalbard. Combining the acoustic data with time-lapse photography, the researchers discovered three distinct underwater acoustic signatures from the glacier. The data allowed them to distinguish among the various stages of the calving process and determine when they were occurring. To date, glaciers have been monitored primarily with satellites, which can track only large pieces of ice. Hydroacoustics could allow researchers to track smaller ice blocks and better monitor global ice loss as Earth’s temperature rises.
January 29, 2015 2:30 PM

Climate models don’t overestimate global warming, says study

Los Angeles Times: Even though Earth has appeared to be experiencing a global warming hiatus over the past 15 years, climate models are accurate in their predictions of rising global temperatures, according to a new study published in Nature. Piers Forster of the University of Leeds in the UK and colleagues looked at climate models that cover 1900–2012 and focused on 114 possible 15- and 62-year intervals. Although they found no inherent bias in the models, they did notice that the shorter time intervals were more susceptible to errors caused by manmade activity and by unpredictable periodic climate variations often caused by ocean fluctuations or volcanic activity. The simulations for longer periods tended to more closely match observations. Furthermore, 9 of the 10 warmest years on record have occurred since 2002.
January 29, 2015 1:17 PM

New House science spending chair is a fiscal conservative but a science supporter

Science: John Culberson (R-TX) is the new chair of the Commerce, Justice, Science (CJS), and Related Agencies spending panel in the US House of Representatives. CJS oversees a large portion of US science research spending, including the funding for NASA, NIST, NSF, and the National Oceanic and Atmospheric Administration. Culberson says that he has had a lifelong passion for science despite his chosen career in law. He also says his desire to support government investment in science does not contravene his fiscal conservatism. However, that support seems to be limited to space science and basic research and does not include the social and behavioral sciences. He says he supports fellow Texas representative Lamar Smith's efforts to focus NSF's research grants on basic science.

January 29, 2015 12:03 PM

Ancient meteorite provides hints about Earth's nitrogen

Ars Technica: Nitrogen composes about 78% of Earth's atmosphere and is the most common pure element on the planet. However, the nitrogen on Earth does not occur in the same isotope fractions as the nitrogen found in the Sun or in the tails of comets. A new analysis of an ancient meteorite may provide some clues as to where Earth's nitrogen came from. Transmission electron microscopy and secondary ion mass spectrometry reveal that the meteorite contains the mineral carlsbergite. The mineral's characteristics suggest it was formed in the presence of ammonia (NH4), which likely came from ice in the Sun's protoplanetary disk. That ice could later have been part of the material that accreted to form Earth. It is possible that the different isotope ratios of nitrogen found in the Sun and in comets blended in such a way as to produce the nitrogen mix now present on Earth.

January 28, 2015 4:04 PM

Nanostructured membrane boosts performance of lithium-air battery

MIT Technology Review: Lithium-air batteries have a theoretical energy density 10 times that of current lithium-ion batteries. In a car, they would provide energy comparable to that of a full tank of gas. However, current models are still far from reaching that energy density, and the number of times they can be recharged is limited. Lithium-air batteries work by allowing lithium ions to react with the oxygen in air to create lithium oxide. Recharging them involves breaking back down that molecule. The batteries' ability to be recharged is limited because the lithium oxide tends to bond to one of the battery's electrodes, covering the catalyst that facilitates the breakdown of the lithium oxide. A team of researchers from Yale and MIT has developed a new membrane made of catalyst-coated nanofibers to which the lithium oxide doesn't bond. The extra catalyst increases the battery's energy density and doubles the number of recharge cycles. However, the experimental battery can be recharged only about 60 times before it needs to be replaced. Commercial car batteries should be able to be recharged roughly 1000 times. The battery also uses pure oxygen instead of air because air's carbon dioxide reduces the battery's efficiency.

January 28, 2015 12:45 PM

Oldest planetary system discovered so far formed 11.2 billion years ago

Los Angeles Times: Based on data collected by NASA’s Kepler spacecraft, astronomers have identified an ancient star, called Kepler-444, that has five planets in orbit around it. Smaller than Earth, the planets are thought to be rocky terrestrials rather than gas giants. The system is located some 117 light-years from Earth and formed about 11.2 billion years ago, when the universe was just 2.6 billion years old. The low metal content of Kepler-444 indicates its extreme age because metals have formed and increased in abundance since the Big Bang. By studying the frequency at which the star pulsates, astronomers were able to determine its mass, radius, and density. They detected the planets indirectly, by noting the periodic dimming of the star when the planets passed in front of it. The discovery indicates that Earth-sized planets could have formed throughout most of the universe’s history and that life could have developed very early on.
January 28, 2015 12:03 PM

Soil-mapping satellite scheduled for launch

Nature: Scheduled for launch on 29 January, NASA's Soil Moisture Active Passive satellite will use microwave signals to measure soil-moisture levels everywhere on Earth and to determine whether the soil is frozen. Clear measurements of soil moisture will help improve water availability models, which are important for both urban and rural areas. The data will help insurance companies to improve crop price models and allow scientists to better monitor droughts and other climate trends. The information on frozen and thawed soil can be used by the military for planning troop movements and by scientists for measuring polar melt due to climate change.

January 28, 2015 10:55 AM

Smart scanner developed to detect potholes

BBC: Potholes, the bane of drivers, form as the asphalt used on roadways degrades. Large potholes can damage vehicles and disrupt traffic flow. Now researchers have found a way to look for potential pothole sites before the potholes form. They have mounted 2D and 3D scanners on the front of a van, which drives around and captures images of road surfaces. A computer algorithm is used to distinguish among different surface textures, including tire marks, oil spills, and previous pothole repairs. It is looking for the loss of fine and coarse aggregate particles from the asphalt mix, which is the hallmark of pavement degradation, called raveling. In a test, the system took just 0.65 second to process the data and identify 900 potential sites.
January 27, 2015 3:15 PM

First recordings of whole-brain neural activity of an unrestrained animal

MIT Technology Review: Recording neural activity for an entire brain has only ever been done with animals that are held in place. Recordings of unrestrained animals have been limited to small sections of the brain. Now Jeffrey Nguyen of Princeton University and his colleagues have recorded whole-brain activity in swimming nematodes. To do that, they suspended a movable camera system above a petri dish holding a nematode and then used image recognition software to keep the camera focused on the animal's head. Combined with a standard imaging technique that causes neurons to fluoresce when they release calcium ions, which is considered a proxy for neural activity, the system allowed them to record five brain volumes per second.

January 27, 2015 3:04 PM

Ocean warming increases frequency of severe El Niños and La Niñas

New Scientist: Previous analysis of the El Niño Southern Oscillation has suggested that warming ocean temperatures are going to cause the number of extreme El Niño events to double in frequency in the 21st century. Now Wenju Cai of the Commonwealth Scientific and Industrial Research Organisation in Melbourne, Australia, and his colleagues have shown that the number of extreme La Niña events is also expected to double. In their analysis, 17 of 21 climate models showed a doubling in frequency, and the average increase across all models was 74%. Cai says it is the uneven heating of the Pacific Ocean that is driving the increasing severity of the two weather patterns. An especially severe El Niño discharges larger amounts of energy from equatorial waters, which allows larger areas of cold water to rise to the surface. The lower temperatures at the ocean surface drive La Niñas.

January 27, 2015 2:00 PM

Large asteroid passes by Earth

BBC: On Monday asteroid 2004 BL86 traveled past Earth at a comfortably safe distance of 1.2 million km, about three times as far away as the Moon. In its wake was its own small moon. At 325 m wide, the asteroid is a fairly large one. Although it could cause considerable damage, including mass extinctions, were it to hit Earth, an asteroid of that size doesn't pass by often. The next is not expected until 2027. Because of the risk, however, scientists have been working to identify and track all asteroids at least 1 km in size. Sky surveys indicate that more than 90% of them have probably been located. Smaller asteroids, of which there could be tens of thousands, pose much less risk because they tend to disintegrate high in Earth's atmosphere.
January 27, 2015 11:55 AM

Why alkali metals explode in water

Nature: Why a piece of sodium or potassium explodes when it comes in contact with water has never been precisely understood. Now, using high-speed cameras, Pavel Jungwirth of the Czech Academy of Sciences in Prague and his colleagues took a closer look at what occurs during the very first milliseconds of the process. Their experiment involved allowing a droplet of a sodium–potassium alloy, which is liquid at room temperature, to fall into a container of water. Within 0.3–0.5 ms, metal spikes shot out from the droplet’s surface and the water around the droplet turned blue. Using computer modeling, the researchers have determined that when the metal drop hits the water, each of the atoms on its surface loses an electron. The electrons become solvated in the water, and their ability to absorb light results in the transient blue color captured by the high-speed imaging. At the same time, the positively charged ions remaining in the metal droplet repel each other and fly apart in what is known as a Coulomb explosion. Hence, the researchers show that the runaway, explosive effect exhibited by alkali metals in water is initially caused by electrostatic forces rather than thermal ones.
January 26, 2015 3:00 PM

UK committee calls for ban on fracking

BBC: The UK Parliament’s Environmental Audit Committee has called for a national moratorium on hydraulic fracturing, or fracking, for shale gas. According to the committee members, fracking will add to carbon emissions and keep the UK from meeting its carbon targets. In addition, it could have adverse environmental impacts on local water supplies, air quality, and public health. The UK Department of Energy and Climate Change disagrees, however, saying environmental risks can be minimized by proper procedures and monitoring, and shale gas would serve as a reliable backup to renewable energy sources, such as solar and wind, which are intermittent. The debate is particularly pressing because of the UK’s participation in the upcoming international conference on climate change in Paris at the end of the year.
January 26, 2015 2:52 PM

Report suggests cuts to NSF ocean sciences infrastructure

Nature: On 23 January the US National Research Council released a report on NSF's ocean sciences division. In 2013 the division began spending more money on infrastructure than on basic science research, so NSF commissioned the report to seek outside advice. The report recommends that the division drastically reduce what it spends on infrastructure. The biggest target is the $386 million Ocean Observatories Initiative, whose operating budget could be slashed by 20%. The report also suggests a 10% cut to the scientific ocean-drilling program and a 5% cut in NSF's contribution to support its 20-vessel research fleet.

January 26, 2015 11:30 AM

Planetary Society to launch solar-powered CubeSat in May

New York Times: The Planetary Society, a nonprofit space advocacy group based in Pasadena, California, plans to launch the first of two solar-powered Lightsail spacecraft into Earth orbit on an Atlas V rocket in May. The craft is planned as a test run for a longer mission set for 2016. For the first flight, the tiny CubeSat will spend four weeks in low Earth orbit, during which all critical functions will be checked before its sails are deployed. Because of its low altitude, the craft will drop out of orbit within days of extending its sails. The second Lightsail will be placed in a higher orbit by a SpaceX Falcon Heavy rocket. Solar-sail technology is being explored as a way of reducing the cost of conducting space missions in the solar system. Ultimately, laser-driven craft might one day allow interstellar travel.
January 26, 2015 11:19 AM

Adjusted ice-sheet models more closely match historical records

Ars Technica: Historical records of sea levels during the past several million years show periods during which they were as much as 20 m higher than they are currently. However, when fed climate details from the periods of highest sea levels, current computer models do not match the historical record. To attempt to correct the models, David Pollard and Richard Alley of the Pennsylvania State University and Robert DeConto of the University of Massachussetts Amherst added two physical processes not currently included in the models—hydrofracturing and cliff failures. Hydrofracturing occurs when water fills crevasses in ice sheets to such depth that the pressure from the water breaks the ice sheet even further. Cliff failures occur when a cliff of ice becomes so tall that it collapses under its own weight. Both processes can increase the calving of icebergs from ice sheets. When that occurs near the grounding line, it can accelerate the loss of a glacier trapped behind the sheet. The adjusted model predicted a much quicker and more severe loss of ice sheets, which could account for much of the historical sea-level rise.

January 23, 2015 2:44 PM

Molecular self-assembly may allow for advancements in microchips

MIT Technology Review: As microchips become smaller, photolithography, the current technique for producing them, is reaching its limits in terms of complexity and expense. A group of researchers at IBM has demonstrated a process of molecular directed self-assembly that may provide a method for making significantly smaller microchips. By carefully preparing a set of block copolymers, and guiding the molecules' positioning using existing photolithography methods, the team was able to create circuit features that were separated by just 29 nm. Current methods are limited to separations of 80 nm. The potential increase in density of microchip circuitry could lead to much smaller chips and significant advances in processing power.

January 23, 2015 2:18 PM

Doomsday Clock moves 2 minutes closer to midnight

Science: The Doomsday Clock is maintained by the board of the Bulletin of the Atomic Scientists (BAS) as a representation of how close the world is to a global disaster. On 22 January, BAS executive director Kennette Benedict announced that the organization would be moving the clock hands 2 minutes closer to midnight, setting the symbolic time as 11:57pm. Benedict said that the reasons for the change include the recent stalling in nuclear disarmament talks and the growing threat of climate change. The time change is just the 18th since the clock's creation in 1947. It has ranged from just two minutes to midnight in 1953 to 17 minutes to midnight in 1991.

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