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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 69 posts for the selected month (January 2015).
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.

January 23, 2015 1:20 PM

Two planets may exist far beyond Pluto

Ars Technica: Two new planets may have been discovered—in our solar system. Their presence has been detected through their apparent gravitational influence on a group of space rocks known as extreme trans-Neptunian objects, which orbit the Sun far beyond Neptune. One of the two possible planets, 2012 VP113, was first detected last year and appears to be about 250 astronomical units away; the second orbits at about 200 AU. If the two do indeed exist and turn out to be much more massive than Earth, their existence would contradict current models of the solar system. Further study will be required before the two objects’ status as planets can be confirmed.
January 23, 2015 11:10 AM

To maintain swarm, jellyfish can swim against current

BBC: Jellyfish tend to congregate in large swarms called blooms, comprising hundreds to millions of organisms. Until recently no one knew exactly how they were able to form and maintain those blooms. Now researchers show that jellyfish can sense ocean currents, actively orient themselves, and swim against the current when necessary. Graeme Hays of Deakin University in Australia and colleagues tagged jellyfish with data loggers to measure their acceleration and orientation; the researchers also used floating sensors to monitor ocean currents. Because jellyfish blooms are proliferating and can disrupt human activities such as swimming and fishing, the researchers hope their findings will allow better predictions of bloom magnitude and movements. However, how the jellyfish know what direction to travel is still unknown.
January 22, 2015 4:15 PM

Laser etching renders metals extremely water-repellent

BBC: Metal surfaces etched by femtosecond laser pulses are more slippery than Teflon and have been shown to be very effective at repelling water. They are so hydrophobic that water drops actually bounce off them, says Chunlei Guo of the University of Rochester in New York, one of the authors of a paper published in the Journal of Applied Physics. Because the water droplets also remove dust particles from the surface, the materials are self-cleaning. Guo and his research team think the technique would be useful in developing countries to create hygienic surfaces for medical or sanitary uses.
January 22, 2015 1:24 PM

Israel's arrest of Palestinian physicist spurs international protest

Nature: Imad Ahmad Barghouthi, a theorist who studies space-plasma physics at Al-Quds University in Jerusalem, was detained without charges on 6 December 2014 as he crossed the border from the West Bank into Jordan. In response to Barghouthi's detainment, several international science organizations have sent letters of protest to the Israeli government and to European organizations that provide research funds to Israel. Barghouthi was on his way to Amman to catch a flight to the United Arab Emirates so that he could attend a meeting of the Arab Union of Astronomy and Space Sciences in Sharjah. Since his arrest, he has been held in an Israeli military prison without being charged under a policy that allows Israel to hold a potential security risk for three months. Jawad Boulos, Barghouthi's lawyer, believes that Barghouthi was detained because of statements he made in support of Palestinian activists during Israel's 2014 invasion of the Gaza Strip. Barghouthi is now scheduled to be released on 2 February, but could be held longer.

January 22, 2015 1:23 PM

Senate amends Keystone XL bill to say that climate change is real

Science: The US Senate voted 98 to 1 to approve an amendment to the Keystone XL Pipeline bill that says climate change is real and not a hoax . Proposed by Sheldon Whitehouse (D-RI), the amendment was one of several put forward by opponents of the pipeline, which would bring oil from Canada to the US. However, it was the only one to be approved. Other amendments that further stated that climate change was directly influenced by human activity and pollution had also been proposed. The Keystone XL bill is heavily supported by Republicans, many of whom have dodged the issue of climate change by saying they aren't scientists. Some, such as James Inhofe (R-OK), had called climate change a "hoax" in the past. Before the vote, Inhofe clarified that statement by saying the hoax is that people think that humanity can change the climate.

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