Physics Today Daily Edition
Los Angeles Times: On Tuesday and Wednesday of this week, a pair of solar flares sent coronal mass ejections (CMEs)—highly energetic waves of plasma—toward Earth. The CMEs will hit Earth today and tomorrow, with the most visible effect being an increase in aurora activity. Some communications and GPS satellites may also be affected, not by the radiation itself but by the effect the radiation has on Earth's upper atmosphere, which will make it more difficult for signals to pass from the satellites to the planet. For people using GPS for general navigation purposes, the disruption won't be noticeable. Only those who need extreme precision in their measurements will be aware of the flare activity.
BBC: The ozone hole over Antarctica has stopped growing and the ozone layer is thickening, according to a new study by the World Meteorological Organization and the United Nations Environment Programme. Furthermore, the ozone layer is expected to return to 1980 levels by midcentury. Scientists credit the 1987 Montreal Protocol, which called for phasing out manmade chlorofluorocarbons used in refrigerators and spray cans. The ozone layer protects Earth from the Sun’s UV radiation, which can damage wildlife, agriculture, and peoples’ skin, eyes, and immune systems. The news comes in the wake of the announcement that atmospheric carbon dioxide levels have reached a historic high. However, reducing manmade CO2 may prove to be much more difficult because of ongoing deforestation and because the gas is integral to so many human activities that currently require the burning of fossil fuels.
New York Times: Japan's new nuclear agency has certified two reactors at the Sendai power plant on the southern island of Kyushu as safe to restart. They are the first nuclear reactors to receive certification since the earthquake and tsunami that caused the disaster at the Fukushima Daiichi plant in 2011. The Nuclear Regulation Authority was established in 2012 to oversee nuclear safety in the country and has been performing inspections and reviews of Japan's 48 operable reactors, which were all closed following the disaster. Before the two newly certified reactors can be restarted, the Kyushu Electric Power Company must perform additional inspections and receive approval from local authorities. Recent polls in the country have revealed that the population is still skeptical about the safety of nuclear plants.
Science: An analysis of historical records in the scientific literature and government documents has revealed 540 000 tons more mercury pollution since 1850 than previously thought. The amount is two and a half times that of earlier estimates. Hannah Horowitz and her colleagues at Harvard University looked at not just atmospheric pollution but also soil and water pollution. Mercury was once used to extract gold and silver from mined ores, which caused a peak in emissions in the 1890s. Horowitz's team discovered a second, larger peak in the 1970s. That peak was likely driven by mercury's use in a wide range of commercial products, such as thermometers and switches, and industrial processes. One major contributor was latex paints, which were very popular in the US in the early 1970s, before mercury's use as a preservative was banned in 1991. The team estimates that 57% of the mercury released over the last century and a half is still circulating in the environment.
Ars Technica: The weathering of minerals on Earth’s surface helps regulate its climate over geological time scales. As the minerals break down, they react with carbon dioxide. In warmer regions, the minerals break down more quickly, resulting in more CO2 being sequestered, which has a cooling effect. In cooler regions, the minerals break down more slowly and less CO2 is sequestered, which has a warming effect. Other factors are known to contribute to such physical weathering, including the breaking up of rocks and soil by tree roots, lichens and fungi, and burrowing organisms. To try and determine to what degree biology influences the process, Ronald Dorn of Arizona State University conducted a 25-year-long study of the weathering of basalt sand samples placed in a variety of environments, from Arizona to Texas. He put the samples in holes augured into the ground, tree roots, ant nests, and other locations. When he compared the samples, the material in the ant nests showed the most weathering, with 50–175 times that of the baseline sand. How the ants cause such accelerated weathering is unknown, but understanding the chemistry involved might one day help humans in their efforts to reduce atmospheric carbon levels.
Guardian: China has suffered a number of food scandals in recent years—from toxic milk to glow-in-the-dark pork to recycled cooking oil. To determine whether food is safe to eat, a set of “smart” chopsticks has been developed. When linked with a smartphone app, they can indicate the levels of freshness, contamination, and nutrition of the food they touch. The product is the brainchild of Baidu, the Chinese version of the search-engine giant Google. Although the chopsticks were demonstrated at the company’s recent technology innovation conference in Beijing, they are not yet ready for mass production.
Nature: Because of the hint of an impending El Niño in January, researchers are watching the Pacific Ocean closely for any changes in temperature and atmospheric conditions. Extreme El Niño events, such as those that occurred in 1982–83 and 1997–98, can severely disrupt global weather patterns. The 1997 event, one of the strongest on record, “caused extreme rainfall along the western coasts of North and South America and drought in Australia and southeast Asia, resulting in thousands of deaths and tens of billions of dollars’ worth of damage,” writes Mark Zastrow for Nature. For that reason, scientists are using satellites, buoys, and autonomous underwater vehicles to gather as much information as possible on the impending event. Not only do they hope to be able to improve their forecasting of future El Niño events, but they also want to better understand El Niño’s history going back thousands of years.
Japan Times: Last weekend the Japanese Aerospace Exploration Agency (JAXA) revealed its Hayabusa 2 spacecraft. As the name suggests, it is a follow-up to JAXA's Hayabusa, which returned to Earth in 2010 after completing a seven-year mission to collect samples from the asteroid Itokawa. Hayabusa 2 will target asteroid 1999 JU3, which contains both carbon and water. JAXA hopes that the samples it collects will provide clues to the origin of life and the formation of the solar system. The agency plans to launch the spacecraft later this year.
Ars Technica: Phase-change materials take on different physical structures depending on the speed at which they are cooled. They are amorphous with a high electrical resistance when quickly cooled, and regular with low resistance when slowly cooled. The materials have been used to create computer memory bits, and last year they were combined with resistors to form logic gates. Now a group of researchers has created a single phase-change memory bit that can act as multiple logic gates. To do that, they provide a low level of heating to the hardware, which makes flipping the bit easier. Then they use pulses of low heat and high heat, representing 0 and 1 respectively, to affect how the bit functions. A single pulse causes the bit to behave as an OR gate, and combinations of pulses can cause it to behave as a NOR or NAND. The low-level heating increased the speed at which the bit switches states to nearly the same speed as modern processors. It is not yet clear whether having a single bit perform multiple gate functions will be useful, but the development is an important proof-of-concept step for phase-change materials in computing.
BBC: Many of the world’s languages are disappearing, particularly in regions with high economic growth, according to a recent paper published in the Proceedings of the Royal Society B. Environmental factors have long played a role in shaping language diversity. However, now it seems that because of accelerating economic development in certain parts of the world, minority languages are giving way and a single, national language is taking over. Tatsuya Amano of the University of Cambridge and colleagues say most at risk are minority languages in North America, Europe, and Australia. The tropics and the Himalayas, home to many small-population languages, may also face similar problems as rapid economic growth commences in those areas. The researchers hope to call attention to the phenomenon in order to better promote and direct efforts to prevent this cultural loss.
Los Angeles Times: The US Environmental Protection Agency is proposing to reduce the federal standard for ground-level ozone. The EPA is required by the Clean Air Act to review the standard every five years. California, which has 16 areas that don’t meet the current ozone limit, will be particularly hard pressed if it is lowered. "We're going to need to have zero or near-zero emissions across the entire economy,” said Sam Atwood, a spokesman for the South Coast Air Quality Management District. Although industry representatives and Republican members of Congress insist that lowering the environmental limit will damage the economy, Janice Nolen, assistant vice president of national policy at the American Lung Association, claims just the opposite: “Since the 1970s, we've reduced major air pollutants by 70% and the economy has more than doubled."
New Scientist: According to a recent paper published in Precambrian Research, both the average rate of continental collisions and the average speed with which the continents change latitude have doubled over the past 2 billion years. Kent Condie of the New Mexico Institute of Mining and Technology and colleagues based their findings on two sets of data: the timing and locations of mountain-range formation and average plate velocities based on magnetic data from volcanic rocks. The researchers think the acceleration may be due to the amount of water in Earth’s mantle, which has recently been found to be much vaster than previously thought. As a result, the mantle may becoming runnier, which could speed up the rock flow. However, the work is considered controversial because it contradicts a previous study that says plate motion has been slowing for the past 1.2 billion years due to the cooling of Earth’s core and mantle.