Physics Today’s online staff summarize the most important and interesting news about science from the world's top media outlets.
Washington Post: Last summer a series of unusual craters—the first more than 30 m across—were found in Siberia. Researchers explained that warming temperatures in the region had caused the layer of permafrost to melt and release bubbles of trapped methane gas. Since then, seven more craters have been found, some of which have become lakes and one of which is surrounded by a collection of mini-craters. Beyond the danger of the methane explosions themselves, the phenomenon is a threat to the region's natural gas fields, which are a major part of the Russian economy. So far, the explosions have not injured anyone, but at least one of them has resulted in a fireball, and there is evidence that methane continues to leak from one of the craters. As Siberia continues to warm—2012 and 2013 were both 5° warmer than the historical average—the threat of these explosions is likely to increase.
The Guardian: NASA's Dawn spacecraft is traveling toward Ceres, the largest body in the asteroid belt, and is taking pictures of the dwarf planet as it approaches. Some of those recent images have revealed unexpectedly bright reflections from the surface. The brightest spot is reflecting about 40% of the light hitting it. Ice is known to account for roughly one quarter of Ceres's mass, so it is likely that the reflection is caused by patches of exposed ice. Normally the ice is contained below the surface, so its exposure was probably the result of the impact of other asteroids. As Dawn approaches Ceres and the resolution of its photographs improves, if ice is the cause of the reflection, the amount of light being reflected should increase to nearly 100%.
Nature: The tsunami that struck the coast of northeastern Japan on 11 March 2011 inundated the Fukushima Daiichi nuclear plant and led to the biggest release of radioactive material into the environment since Chernobyl. In the wake of the disaster, the Japanese government established an extensive and continuing monitoring campaign to track levels of radiation in the nation's food supply. Stefan Merz of the Vienna University of Technology in Austria and his colleagues have analyzed the almost 900 000 food samples in the campaign database. In 2011, the year of the disaster, Merz's team found that 3.3% of food from the region around the power plant had above-limit contamination. By 2014 the percentage had fallen to 0.6%. Food in the rest of Japan was also contaminated: 0.9% in 2011; 0.2% in 2014.
BBC: The tubules that sprout from the slime mold Physarum polycephalum behave in a way akin to an electronic component called a memristor: a resistor whose resistance changes in response to previously applied voltages. Musician Eduardo Miranda and computer scientist Ed Braund, both of Plymouth University in the UK, have exploited that property to create a musical duet. Miranda plays a sequence of notes on a piano, which is then converted into an electronic signal and fed into a tray of P. polycephalum. The mold transforms the signal into a new one based, in part, on the previous sequence of notes. The transformed signal then activates electromagnets that pluck the corresponding piano strings while Miranda continues to play the piano conventionally. The duet will make its public debut on 1 March at the Peninsular Arts Contemporary Music Festival in Plymouth.
Ars Technica: Atmospheric carbon dioxide levels are rising and are indeed contributing to Earth’s greenhouse effect, according to a new study. US researchers have made the most accurate measurements yet of the amount of CO2 in the atmosphere. Looking straight up at the sky, they measured the IR light spectrum, from which they could determine the amounts of various molecules present, including water vapor, CO2, ozone, and methane. They found that between 2000 and 2010, the amount of CO2 rose by 22 parts per million. A greenhouse gas, CO2 absorbs thermal radiation from the planet’s surface and reradiates it back toward Earth, which can cause a rise in atmospheric temperatures. However, because of the complications posed by clouds and other weather phenomena, the effects of rising CO2 levels are not yet completely understood.
Technology Review: To lighten aircraft and automobiles, and therefore increase their fuel efficiency, manufacturers have been using more titanium, a low-density, high-strength metal that is extremely resistant to corrosion. But making titanium involves a multistep process that requires very high temperatures. Now SRI International has developed a way to produce titanium powder, which requires fewer steps and less energy. It uses plasma arcs to cause molecules of hydrogen and titanium chloride to react and form titanium vapor, which then forms a powder as it solidifies. The powder can then be pressed into whatever shape is needed, thus reducing the amount of machining required. SRI is currently refining the process before it attempts to scale up production.
BBC: A computer program developed by Google DeepMind has learned how to play 49 classic Atari video games. In about half the games, it was able to match the abilities of a professional human player. What makes this achievement significant is that the program was not specifically designed to play the games. Instead, it was given only the basic information needed to play them: the raw pixels on the screen and the goal of getting a high score. From that information the program could be presented with any of the games and, in the course of a few hours, learn to play the game with varying levels of success.
Los Angeles Times: An object spotted by the Sloan Digital Sky Survey appears to be a black hole 12 billion solar masses in size. Its redshift suggests it formed when the universe was only 875 million years old. Of the known black holes formed in the universe's first billion years, it is by far the most massive and luminous. This black hole is also a quasar and is pulling in so much of the surrounding material that massive amounts of radiative energy are being released. And that's what makes it unusual. Normally, the pressure from that radiation is expected to gradually slow the rate at which material falls into a black hole. The finding that the black hole reached such a great size in such a short period of time challenges current understanding. Further observations of this black hole could provide more clues into black hole formation and evolution. As the light it emits passes through the material in the intergalactic medium, which was much denser 13 billion years ago, that light could also provide information about the growth of the universe itself.
BBC: Tidal measurements from 2009 and 2010 reveal that sea levels along the Atlantic coastline north of New York City rose by 128 mm over that two-year period. A team of researchers from the University of Arizona and the National Oceanic and Atmospheric Administration split the Atlantic coastline into three regions, with the other two regions stretching from New York City to Cape Hatteras, North Carolina, and from Cape Hatteras southward. They say the increase in level seen north of New York City was higher than any recorded in the past 100 years and is "a 1-in-850 year event." The rise is likely tied to major storms that lifted tides and had a lasting effect on local sea levels.
Nature: In October 2014, following widespread student protests over low pay and delayed payouts, the Indian government announced an increase in the wages that fellowships pay to the country's PhD students. Some of the government agencies, such as the Department of Science and Technology and the Department of Biotechnology, have already implemented the new wage system. Others have not. At least two, the Ministry of Human Resource Development and the University Grants Commission, have announced that they would implement the changes but have not yet done so, nor have they provided timetables for the changes. The delays and lack of information from the funding agencies have driven thousands of graduate students to launch a hunger strike. On 20 February, about 150 student protesters who went to an office of the human resource development ministry in New Delhi were taken to a police station, which further increased tensions between the students and the government.
New York Times: The American Energy Innovation Council is urging the US government to triple its current level of funding for energy research. In the council’s recent report, some of the country’s top business leaders, among them Bill Gates of Microsoft and Jeffrey Immelt of General Electric, say that without dramatically increasing federal funding for technology innovation, the US risks falling behind in the energy race. The US must make more of an effort to both improve existing technologies and create new technologies to provide affordable and sustainable energy to its citizens while limiting greenhouse gas emissions. Safer nuclear reactors, cheaper carbon-capture methods, and better batteries are among the objectives mentioned. Although the report cites some progress on the recommendations the council made five years ago, much more needs to be done. Council members say the upcoming 2016 presidential race may provide some impetus to take up their ambitious recommendations.