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Updated: 5 hours 32 min ago

Asteroid Ceres sports bright salts and hints of buried water ice

23 March 2016

BBC: Pluto tends to steal the show in planetary science these days, but Ceres, the solar system's largest asteroid, is offering up some surprises of its own. New data from NASA's Dawn spacecraft, presented at the Lunar and Planetary Science Conference in The Woodlands, Texas, reveal evidence of buried water ice and offer an unprecedented look at a mysterious bright region in the middle of a crater. The probe's GRaND instrument has remotely probed the chemistry of the asteroid's surface and found large concentrations of hydrogen at high latitudes. Those hydrogen atoms may be part of water molecules frozen just under the surface. The new images of Ceres's puzzling bright spot show a feature resembling a fried egg. Scientists suspect the feature is largely composed of magnesium sulfate salts that remained on the surface after the water that accompanied them vented into space. Dawn's orbit now has the probe just 385 km above the surface of Ceres.

New solid electrolyte battery is competitive with traditional lithium-ion batteries

23 March 2016

Ars Technica: Traditional batteries use liquid electrolytes because they are very effective at transporting ions. But the chemicals can be hazardous and have a limited range of operating temperatures. A 2011 paper showed that some solid crystals could effectively transport lithium ions by creating a line of lithium atoms within the crystal structure, but the known materials were either unstable or unreasonably expensive. Now the authors of that paper have identified two more materials that overcome both problems while also doubling the conductivity. The researchers used the new materials to build batteries that had operating temperatures between −30 °C and 100 °C, a much wider range than traditional lithium-ion batteries. They also had a charge/discharge rate competitive with supercapacitors and an energy density competitive with traditional lithium-ion batteries. The researchers still face trouble finding electrodes that can work across the same temperature range.

Forrest Richard Gilmore

22 March 2016

Rudolf Haag

22 March 2016

<p>Andrew S. Grove</p>

22 March 2016

<em>Kepler</em> finds first visible-light sign of supernova shock breakout

22 March 2016

Guardian: Over a three-year span, NASA's Kepler space telescope captured two stars going supernova. Just before one of the stars exploded, researchers spotted evidence of a shockwave and pulse of light, an event that is thought to allow the star to self-destruct. This is the first sighting with visible light and with a high level of detail. Such a pre-explosion signal had previously been seen only in x-ray images. Brad Tucker of the Australian National University and his colleagues think the other star was so large that the shockwave wasn't strong enough to escape the star's gravity. The researchers hope that further analysis of Kepler data will reveal more supernovas, especially now that the telescope's field of view has been expanded to include many galaxies.

Climate researchers argue changes will be significant in decades, not centuries

22 March 2016

New York Times: A study that stirred controversy among climate scientists when a draft version first circulated last year has now been published in the journal Atmospheric Chemistry and Physics. In the paper, retired NASA climate scientist James Hansen and colleagues argue that the amount of warming set as a goal at the Paris climate talks is enough to cause major climate changes by the end of this century. The researchers reached that conclusion by comparing the modern situation with a period roughly 120 000 years ago, when Earth warmed naturally to a temperature only slightly higher than current levels. In that era most of the polar ice sheets melted and sea levels were 20–30 feet (6.1–9.1 m) higher. Melting of the polar ice sheets, the researchers say, would release a large amount of freshwater that could slow or even stop the ocean's system of currents that redistribute heat around the planet. As a result, more heat would accumulate in the oceans, accelerating melting, exacerbating the temperature difference between tropical and polar regions, and triggering powerful storms. The paper cites controversial evidence for significant storms in the previous warm period. The slowdown of ocean currents is also not widely accepted by climate researchers. But its inclusion in the paper may result in reexamining the scenario using modern computer simulations that were not available when the theory was proposed more than a decade ago.

Lead found in ancient writing on Herculaneum scrolls

22 March 2016
BBC: Some 2000 scrolls were buried in a villa in Herculaneum when Mount Vesuvius erupted in AD 79. When unearthed in the 18th century, the scrolls were found to be badly charred and fragile; any attempt to read them caused further damage. Now Emmanuel Brun of the European Synchrotron and colleagues have used 3D x-ray imaging to reveal the writing. Surprisingly, the ink contains high levels of lead. Researchers had thought that metal was not used in ink until some four centuries later. Knowing about the lead in the ink should help optimize future scans and discern the writing, says Brun.

Yellowstone geysers are partially fueled by carbon dioxide

22 March 2016
Science News: Every one to two hours, the geysers in Yellowstone National Park spew thousands of liters of water tens of meters into the air. Although the geysers are fueled by magma pools lying 20 km underground, it was discovered that the magma can’t actually heat the water enough to make it boil. To find out what pushes the geysers beyond the tipping point, Bethany Ladd and Cathryn Ryan of the University of Calgary in Canada collected water samples every 10 to 20 minutes during the intervals between eruptions. They found that as carbon dioxide gas accumulates in the water, it lowers both the boiling point of the water and the pressure inside the geyser conduit. That carbonation builds until the groundwater flashes to steam and erupts. Such eruptions can occur elsewhere in the world, as happened in 2014 at Japan’s Mount Ontake volcano, when more than 50 people were killed and many more injured. Better understanding of the role gas plays in groundwater eruptions could help provide early warning of such potential disasters, particularly when there have been no earthquakes or other visible evidence to indicate an imminent eruption.

No need for researchers to break the law to access scientific publications

21 March 2016
Contrary to a New York Times commentary, research papers are becoming more available, and the transition is happening sensibly and responsibly—and lawfully.

A nonlinear look at music

21 March 2016
Recorded music and other time series carry information on small and large scales. A new hierarchical analysis can help make sense of it all.

High-entropy alloys could make nuclear reactors last longer

21 March 2016
New Scientist: One of the major causes of decay in nuclear reactors is the high number of neutrons produced. Neutrons interact with steel in the containment system and make the metal brittle by knocking atomic nuclei out of place. High-entropy alloys are so named because the distribution of the elements in the alloy is random, compared with the more regular arrangement of atoms in steel. These materials are only now being produced with high enough quality for use in research. Kai Nordlund of the University of Helsinki, Finland, and his colleagues have now shown that two high-entropy alloys are much more resistant to neutron radiation than steel. The researchers made extremely thin disks of a nickel-iron alloy and a nickel-cobalt-chromium alloy and then fired a beam of gold and nickel atoms at the disks to simulate the reactor environment. Compared with a pure nickel disk (used in place of steel because calculations are simpler), the alloys experienced two to three times fewer defects. However, it will likely be years before any such material is fully proven as a replacement for steel in nuclear reactors.

Custom enzyme incorporates silicon into hydrocarbons

21 March 2016
Science: All known life is carbon-based. But in theory, other elements, such as silicon, could serve as the chemical basis for life. In an attempt to show that silicon life-forms are possible, Frances Arnold of Caltech and her colleagues have evolved what might be the first step in demonstrating the viability of silicon biochemistry. Arnold's team focused on a common enzyme called cytochrome c, which is present in many organisms' cells and normally functions to transport electrons between proteins. The researchers found that cytochrome c has an additional role in a species of bacteria common in hot springs: In rare cases, the enzyme adds silicon atoms to hydrocarbon molecules. Arnold's team selectively isolated the organisms that produced the most silicon-rich hydrocarbon molecules. In just three rounds of selection, the organisms were including silicon in hydrocarbons 2000 times as frequently as the original strain. The resulting compounds, called organosilicates, aren't particularly useful because they are much shorter than the organosilicates used to produce adhesives and sealants. However, showing that a biological process can produce silicon-based chemicals is a step forward in proving that silicon-based life is more than a theoretical possibility.

Noble gases may have come to Earth via comets

21 March 2016
Science News: It has long been thought that asteroids and comets brought to Earth much of the raw material needed for life, such as water, carbon, nitrogen, and noble gases. But which brought what has been a matter of debate. Scientists last year proposed that it was more likely that asteroids were responsible for most of Earth’s water. However, comets may have brought other chemicals. Now, based on data provided by the Rosetta spacecraft, Bernard Marty of France's Petrographic and Geochemical Research Center and colleagues say they have found evidence of argon in the atmosphere of comet 67P/Churyumov–Gerasimenko. Furthermore, the researchers say that judging by the composition of meteorites, "the amount of prebiotic material delivered by comets could have been quite considerable—equivalent to the present-day mass of the biosphere."

Climate change allowing invasive beetles to spread north up US East Coast

21 March 2016
New York Times: The southern pine beetle, which is native to the southeastern US, has already caused more than a billion dollars in damage to the timber industry. And as winters continue to get milder because of climate change, the beetle has begun expanding its range. As early as 2002 the beetle had moved up the coast as far as New Jersey, where it has destroyed more than 30 000 acres of forest. By last year the beetle had moved on to Long Island, Cape Cod, and Martha’s Vineyard. The invasive species kills pine trees by riddling the bark with tunnels, laying eggs, and spreading a damaging fungus. To fight the invasion, the forestry service has been cutting infested trees and thinning unaffected sections of forestland. Besides the southern pine beetle, the warming climate is also enabling the northward spread of other pests, such as ticks and mosquitoes, which can carry Lyme disease and dengue fever, respectively.

Paralympic runners with left-leg prostheses are at a disadvantage

18 March 2016
New Scientist: When running races on a curved track, most athletes go slower on the curves than on the straight stretches. However, for athletes with unilateral leg amputations, there is an additional impediment: Amputees whose affected leg is on the inside of the curve run about 3.9% slower. That was the finding of a recent study published in the Journal of Experimental Biology. Because track competitions are run in the counterclockwise direction, those with a prosthesis on the left leg will be at a disadvantage. Researchers recorded the race times of 17 runners, both amputees and nonamputees. The scientists found that the fastest runners exert the most force on the ground in the shortest possible time and that on curves the inside leg of all runners spends more time in contact with the ground than the outside leg. Running prostheses are lighter than biological legs and thus create significantly less force. Moreover, prostheses can’t flex to adjust for curves the way biological ankles can. To help even the odds, the researchers say, sprinters with left-leg prostheses could race in the outer lanes or in special heats in which the participants run in a clockwise direction.

<em>New Horizons</em> turning up gold mine of information on Pluto

18 March 2016
Los Angeles Times: Despite their distance from the Sun, both Pluto and its moon Charon have experienced more geological activity than scientists had expected. Since its flyby last year, the New Horizons spacecraft has been sending back high-resolution images of both worlds and of four other Pluto satellites—Styx, Nix, Kerberos, and Hydra. Five papers published this week in Science interpret the data collected about surface features and atmospheres. Both Pluto and Charon appear to have a very complex geology, dating back 4 billion years, and Pluto may still be geologically active. So far, New Horizons has transmitted less than half of all the data it collected during the historic flyby.

Questions and answers with Adrienne Kolb

18 March 2016
The recently retired Fermilab archivist and historian discusses her role in piecing together the puzzle that was the ill-fated Superconducting Super Collider project.

Supercomputer simulates blood flow in circulatory system

18 March 2016

BBC: A supercomputer simulation presented at the American Physical Society meeting in Baltimore, Maryland, this week, models the human circulatory system in three dimensions. The simulated network, which tracks blood flow through all arteries larger than 1 mm across, is based on images captured by full-body CT and MRI scans of the circulatory system of a single person. Flow measurements in the simulation closely matched those of a 3D printed version of the circulatory system, both when the blood was free-flowing and when it was pulsed in a way that mimicked a heartbeat. Amanda Randles of Duke University and her team attempted the project primarily as a proof-of-concept because most previous simulations have focused on smaller sections of the circulatory system. The goal is to model how medical interventions, such as stents or other surgical modifications, might affect the system as a whole.

Hints of new particle in LHC data grow somewhat stronger

18 March 2016
Nature: Last December, the ATLAS and CMS detector teams at CERN's Large Hadron Collider (LHC) announced that they had seen a bump in the data that indicated the possibility of a new particle with a mass around 750 GeV. Both teams found the signal in the production of pairs of gamma-ray photons, but neither detector approached the 5 σ confidence level necessary to confirm a discovery. A secondary analysis of the data presented on 17 March at a conference in La Thuile, Italy, has somewhat increased the confidence level. The CMS reanalysis included 23% more data and a recalibration to account for radiation affecting the measurements. The resulting signal increased from a 1.2 σ to a 1.6 σ confidence level. A reanalysis of the ATLAS data saw a drop in confidence, though not enough of one to outweigh the increase in the CMS data. A new particle at 750 GeV is not predicted by any widely accepted theories, which makes the potential discovery so exciting. LHC researchers believe they will have enough data by midsummer to declare whether the signal is a new particle or just a statistical fluctuation.

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