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 46 posts for the selected month (December 2014).

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December 17, 2014 11:57 AM

Microfabrication technique doubles solar-cell efficiency

MIT Technology Review: The technology behind manufacturing solar cells is similar to that behind making microprocessors. French company Soitec has exploited its expertise in microfabrication to develop a solar cell that adds four semiconductors in two layers. Each semiconductor absorbs energy from different parts of the light spectrum; together they convert sunlight to energy at a more efficient rate than one wide-spectrum semiconductor, which is more typical in other designs. Although the cell's solar efficiency is now at 46%, the process is currently expensive compared with the price of making competing products.

December 17, 2014 10:39 AM

Satellite sees ground movement after quake

BBC: Europe's Sentinel-1a satellite, which was launched earlier this year, has provided the first high-resolution images of ground movement after an earthquake. Back in August, California's Napa Valley suffered an earthquake. Because Sentinel-1a flies over and takes a snapshot of the surrounding area every 12 days, researchers have been able to track the earthquake's aftermath. The high-resolution images have captured the surface creeping forward at a rate of 5 cm per month. The data will allow researchers to see which parts of a fault line "stick" and potentially cause an earthquake and which parts flow over the surrounding rock.

December 16, 2014 4:45 PM

Raman spectroscopy finds rickets disease in Tudor sailors

Daily Mail: Bones and artifacts from an almost 500-year-old shipwreck are now being analyzed using Raman spectroscopy and DNA analysis. When Henry VIII’s flagship Mary Rose sank in battle on 19 July 1545, more than 400 men, and one dog, died. The wreck settled into the muddy bottom on the floor of the Solent, the strait separating the Isle of Wight from mainland England. It lay there preserved until October 1982, when it was raised and an ambitious conservation effort begun. Over the next three decades, the ship’s hull underwent constant spraying with millions of liters of water and wax chemicals to preserve it. In addition, bones of the sailors who perished on board have been examined. One thing the researchers discovered was that many of the sailors appear to have suffered from metabolic bone disease, such as childhood rickets.
December 16, 2014 1:38 PM

Modeling behavior of synthetic materials

The Telegraph: Computationally modeling chemical processes from quantum mechanical principles has been a challenging task because of the large number of pieces and the large number of steps in interactions that need to be calculated. Now Peter Coveney, James Suter, and Derek Groen of University College London have developed an efficient way of modeling the behaviors of composites of clays and polymers from the quantum scale up. They were able to accurately model the characteristics of synthetic materials they'd created in the lab; they began the modeling with the behavior of the materials' electrons and then progressed to the atomic level and then to the molecular level. Their modeling system could be useful for predicting the behaviors of potential new materials, including new composites that contain molecules like graphene.

December 16, 2014 12:07 PM

Nuclear sites get federal historical park status

New York Times: On 12 December Congress approved the establishment of a new national historic park to preserve sites associated with the World War II secret Manhattan Project, which built the world's first atomic weapons. The park will encompass lands and buildings in New Mexico, Tennessee, and Washington, including the home of J. Robert Oppenheimer, the scientific director of the project, and buildings where much of the research and construction of the Trinity device and the Fat Man and Little Boy bombs took place. The effort to preserve the various sites was led by the Atomic Heritage Foundation. President Obama is expected to sign the legislation into law this week.

December 16, 2014 11:41 AM

Densest Amazon store of carbon is in the peat

BBC: A 120 000 km2 area that accounts for just 3% of the Peruvian Amazon basin contains almost 50% of the basin's carbon stock. Freddie Draper of the University of Leeds, Katy Roucoux of the University of St Andrews, and their colleagues combined two years of measurements on peat depth, density, and carbon percentage with satellite imagery to reach that conclusion. The imagery revealed that the peatlands were more widespread than expected. The direct measurements of ground carbon revealed that the peat accounted for 90% of the area's carbon. Draper and Roucoux say that the peatlands are still mostly intact but that preservation efforts should be started now to prevent any damage to the ecosystems.

December 15, 2014 4:16 PM

Large number of methane deposits releasing gas along US East Coast

Earth Magazine: Sea-floor methane deposits are commonly found leaking gas in tectonically active areas or in areas rich in petroleum. They are considered to be a potentially significant contributor of greenhouse gases. Now Adam Skarke of Mississippi State University and his colleagues have found 570 methane seeps along the tectonically quiet and oil-poor East Coast of the US. Skarke's team used multibeam sonar, commonly used for producing 3D maps of the sea floor, to find the seeps. Previous scans of the region did not have a resolution capable of detecting the small bubbles up to 1.6 km below sea level. Despite the large number of seeps found, the amount of gas being released by them is quite small. However, the discovery suggests that the search for seeps should be expanded to areas that were not previously considered likely sites.

December 15, 2014 3:28 PM

Fuel cell provides alternative for carbon capture

New York Times: FuelCell Energy has received a $2.5 million grant from the US Department of Energy for an experimental fuel cell it developed that can be used to capture carbon dioxide emissions from coal power plants. The fuel cell combines natural gas and air without combustion to produce CO2 and steam and to generate electricity. Then the mixture is easily cooled to −40 °C so that the CO2 can condense and separate out. When the fuel cell is fed waste air containing 13% CO2, about the level from a coal power plant, the additional CO2 is captured in the condenser. As an additional bonus, the fuel cell generates excess electricity that can be used by the power plant. 

December 15, 2014 1:40 PM

Star birth appears to drive galactic gas cloud formation

Ars Technica: The visible matter that makes up galaxies is primarily in the form of stars, but many galaxies have large clouds of molecular gas around them. How that gas got there is unclear because most theories about galaxy formation predict that the gas should have stayed in the galaxies and coalesced into stars. Now observations of a distant galaxy may provide some clues into the process. The observed galaxy, J0905, is extremely compact, with half of its star formation coming from a region just 100 parsecs in diameter. It is spewing gas outwards into space at a flow rate of 2 500 km/s, 10 times more than the average for other galaxies. Curiously, the mass of the gas lost each year is roughly equal to the mass of new stars that J0905 produces each year. Because of the galaxy's compactness, the combined radiation from the new stars appears to be the source of the "wind" driving the gas out of the galaxy.

December 12, 2014 4:00 PM

Cutting carbon emissions could have more immediate benefits, says study

Ars Technica: Previous studies have proposed that because of the heat capacity of Earth's oceans, the benefits of cutting fossil fuel emissions could take almost a half century to be realized. However, new research shows that the median time between a given carbon dioxide emission and maximum warming may be much less than that. The researchers gauged Earth’s temperature response by simulating the effect of a pulse of 100 gigatons of CO2 that abruptly ceases. The researchers focused on three variables: climate sensitivity, the ocean’s thermal inertia, and carbon cycle activity. For 90% of their simulations, surface temperature stopped rising in as little as 10 years. The point of the study was to demonstrate the early benefits of cutting greenhouse gas emissions.
December 12, 2014 2:10 PM

Wyoming cloud seeding experiment modestly increases snowfall

Nature: In the western US, winter snowpack, an important water resource for many communities, has been diminishing due to global warming. The state of Wyoming recently completed a six-year study to evaluate the effectiveness of cloud seeding for increasing snowfall in the Medicine Bow and Sierra Madre Ranges. The two mountain ranges are situated relatively close to each other and experience similar weather conditions. When supercooled water was detected in clouds approaching the mountains, the clouds over one range were sprayed with silver iodide particles, and those over the other, which served as the control, were not. The 118 instances of cloud seeding that resulted were not deemed enough by the researchers to form any firm conclusions. However, by eliminating parts of the test that went wrong, the researchers found that seeding resulted in 5–15% more precipitation. As a result, they recommended the state start a cloud-seeding program.
December 12, 2014 11:47 AM

Russia to dismantle Soviet-era nuclear waste storage ship

New Scientist: The cargo ship Lepse contains 638 fuel rods from Soviet-era Russian nuclear-powered ships and submarines. The fuel rods produce 2.7 × 1016 Bq of radioactivity, equivalent to the radiation released by the Chernobyl disaster. For the last 15 years the ship has been sitting in a harbor in Murmansk, Russia. In October, it was towed into dry dock for dismantling. If there is an accident during the process, significant radiation could be released. Russia has previously refused assistance for the project, likely because of national secrecy concerns. The threat of radiation to the Arctic region from Russian nuclear waste is not limited to the Lepse. Sixteen nuclear reactors have been deposited offshore, many with their fuel assemblies still onboard. Two of those—one in a submarine that sank while being towed in for scrapping and the other in a submarine scuttled after an accident—account for half of the radioactive waste in the Arctic Ocean. Because of the corrosiveness of saltwater, both submarines are considered at risk of leaks that could seriously contaminate the Arctic.

December 11, 2014 1:43 PM

Device based on spider sense can detect vibrations

BBC: Two years ago, scientists discovered what they called the "lyriform organ" on spiders' legs, which makes use of a series of slits of varying lengths to detect small vibrations from relatively far away. Now, Mansoo Choi of Seoul National University in South Korea and his colleagues have developed a vibration sensor based on that structure. The sensor is made from a thin layer of platinum placed on a flexible polymer, which is then bent just enough to create a pattern of cracks in the metal similar to the slits in the lyriform organ. When electricity is applied to the sensor, vibrations are produced that periodically widen the cracks, thereby changing the resistance across them. Placed on a violin, the sensor could tell the difference between the various notes being played; on a person's wrist, it could measure the person's pulse. The researchers are working to make the sensor more durable and to find a cheaper material than platinum. They also want to improve the device's sensitivity and find more applications for it.

December 11, 2014 1:33 PM

Analysis of arXiv submissions reveals international plagiarism patterns

Science: The final step before papers are approved for publication on the arXiv eprint server is an automated comparison of their text with the other papers in the system. Paul Ginsparg of Cornell University and founder of arXiv, along with one of his students, Daniel Citron, ran an analysis of the 757 000 papers in the system to determine how often "text reuse" occurs. They filtered out legitimate quotes and review articles and found that 1 in 16 authors quoted their own previous papers at length. They also found that 1 in 1000 authors copied a paragraph's worth of text from other authors without citing those papers. Geographical data reveal that plagiarism is significantly more common in some countries than in others. In total, just 6% of submitting authors were flagged for plagiarism. However, in Bulgaria, 20% of submitting authors were flagged; in Iran, 15%; in the US, 5%; and in both Germany and New Zealand, fewer than 5%.  Ginsparg and Citron believe the discrepancy is due to differences in academic cultures.

December 11, 2014 12:10 PM

Comet 67P’s water differs from that of Earth's

New Scientist: Although comets are partly composed of water ice and periodically visit the inner solar system, it is unlikely that Earth got its water from such a source, according to a new study. Data from the European Space Agency’s Rosetta spacecraft, which landed a probe on the surface of comet 67P/Churyumov–Gerasimenko last month, reveal that 67P’s water has about three times as much deuterium as water on Earth. However, the data may be incomplete, say the researchers: It is possible that pockets of water on the comet have different deuterium-to-hydrogen ratios or that the two halves of the odd-shaped comet have different D/H ratios, which would indicate that the comet is actually composed of two distinct bodies that collided long ago. "In the end, Earth's oceans are probably a mix of many things," says Kathrin Altwegg of the University of Bern and lead author of the paper.
December 11, 2014 10:45 AM

Study finds less plastic than expected in world’s oceans

Nature: At least 5.25 trillion plastic pieces, weighing some 268 940 tons, are currently floating in the world’s oceans, according to a recent study by Marcus Eriksen of the Five Gyres Institute in Los Angeles and his colleagues. Although that sounds like a lot, it represents just 1% of total annual global plastic production. Furthermore, three-fourths of the total mass of plastic consists of pieces larger than 200 mm across. Because larger pieces tend to break up into smaller ones, researchers had assumed they would find evidence of much more microplastic. To explain the small proportion of microplastic found, the researchers propose that either the pieces are so small they slip through the sampling nets, or they get washed ashore, sink to the deep sea floor, or somehow degrade or are eaten and digested by seals or other animals. The researchers say further study is needed to determine where the plastic is going and to understand the many processes involved.
December 10, 2014 3:21 PM

Science in the spending bill

Science: Last night the US House of Representatives and Senate agreed upon a partial spending bill for fiscal year 2015. Science was not expected to face many funding challenges, and there were no major surprises regarding US research programs and organizations. The Department of Energy's funding will remain at $5.1 billion and will continue to support ITER; however, funding for the project will be contingent upon progress made. NASA will see an increase of $364 million for a total of $18 billion overall. The space science division accounts for $94 million of the increase; its budget will rise to $5.245 billion. NSF will see a relatively large increase of 2.4%, to $7.344 billion, with major growth in the agency's research directorates and education program; the agency also received funding for a planned move to a new facility. NIST's budget will increase by $14 million to $864 million, and the National Oceanic and Atmospheric Administration will get $126 million more than it received in 2014, for a total of $5.4 billion. Other projects funded directly include a safety study of Yucca Mountain for nuclear waste storage.

December 10, 2014 2:30 PM

Polymer skin adds sensory capabilities to prosthetics

MIT Technology Review: A “smart” skin laden with integrated sensors has been developed for use on prosthetic limbs to allow the wearer to sense heat, pressure, and moisture. In a recent paper published in Nature Communications, researchers in Korea and the US describe a polymer covering they have created that comprises networks of sensors made of ultrathin gold and silicon. Not only do the sensors provide touch similar to that of a normal hand but they also have the ability to stretch like human skin. In addition, integrated actuators make the artificial skin feel warm to the touch. The technology is innovative; connecting it to the human nervous system is the next challenge.
December 10, 2014 2:10 PM

UN climate meeting prompts Catholic bishops to curb fossil fuels

BBC: Negotiators are currently gathered in Lima, Peru, for this year’s UN Climate Change Conference. The goal of the meeting, which is being held 1–12 December, is to reduce global greenhouse gas emissions and limit global temperature rise to 2 °C. For the first time, senior officials of the Roman Catholic Church are weighing in on the negotiations, calling for an end to fossil fuel use, the phasing in of 100% renewable energy, and an even stricter limit to global temperature rise of just 1.5 °C. According to Monsignor Salvador Piñeiro García-Calderón, Archbishop of Ayacucho and president of the Peruvian Bishops' Conference, the church feels an obligation to protect the planet and its inhabitants, especially the poorest people, who are affected the most by climate change yet have contributed the least to the problem.
December 10, 2014 2:03 PM

Tsunami notification system still fails in significant ways

Nature: This month marks the 10th anniversary of a magnitude 9.1 earthquake that struck off the coast of Sumatra and triggered a tsunami that killed more than 230 000 people. In response to that disaster, an international effort funded the creation of the Indian Ocean Tsunami Warning and Mitigation System. The IOTWS uses a network of seismometers, sea-level gauges, and buoys connected to monitoring centers to detect tsunamis and alert at-risk nations. However, the system does not provide direct notification to populations in shoreline areas; distributing the information to those populations is left up to each nation. Now that the initial funding is nearly used up, maintaining the system costs the participating nations between $50 million and $100 million each year. Without increasing costs, expanding the notification system and educating populations to respond appropriately will become more difficult.

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