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