# 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 77 posts for the selected month (August 2016).

August 26, 2016 1:16 PM

### High-resolution mapping confirms rate of Greenland ice sheet melting

The Guardian: Greenland's ice sheet is one of the largest on Earth. Malcolm McMillan of the Center for Polar Ice Observing and Modeling in the UK and his colleagues recently used the satellite Cryosat-2 to map Greenland with a resolution of 5 km. The satellite uses radar altimetry to measure the height of the surface. By taking images over time, the researchers were able to measure changes in height; an increase in height corresponds to an increase in ice thickness. However, those measurements don't account for changes in density (the top layer could be ice or snow), surface roughness, water content, and other factors. McMillan's team examined the satellite imagery collected between 2011 and 2014 and accounted for all the variations. The scientists calculated that 270 billion tons of ice was lost per year, closely matching previous measurements from other groups using different measurement techniques. They also found that the western part of the sheet experienced more ice loss than the eastern side, and that a region less than 1% of the area of the sheet was responsible for 10% of the ice loss.

August 26, 2016 1:12 PM

### South Korea says it can mass produce tritium for fusion reactors

Korea Times: South Korea's National Fusion Research Institute announced on 24 August that it has developed a process capable of producing 50 kg of tritium breeder pebbles per year. Tritium, a radioactive isotope of hydrogen with one proton and two neutrons, is a common fuel for nuclear fusion reactors. Unlike hydrogen's other isotope, deuterium, tritium does not occur naturally in large quantities and so has to be artificially produced. Previous processes have not produced significant quantities of the isotope. According to the Institute for Energy and Environmental Research, between 1955 and 1996 the US produced an estimated 225 kg of tritium.

August 26, 2016 1:06 PM

### Newly found galaxy is 99.99% dark matter

Washington Post: Dark matter accounts for much of the mass in the universe, but it is not evenly distributed. About 83% of the Milky Way's mass is due to dark matter; the percentage is considerably higher for some dwarf galaxies. Now Pieter van Dokkum of Yale University and his colleagues have found a galaxy, called Dragonfly 44, that has roughly the same mass as the Milky Way yet has only 1% as many stars. The researchers estimate that 99.99% of the galaxy's mass is from dark matter. Because Dragonfly 44 is about average when it comes to galactic size, scientists suspect that similarly dark matter–dominated galaxies are relatively common.

August 26, 2016 12:45 PM

### Storm-triggered S waves tracked for first time

BBC: Earthquakes aren't the only phenomena to send seismic waves through Earth's interior. When a large storm forms water, the energy from colliding ocean waves can create weak seismic activity—dubbed a microseism—that travels through the crust. The pressure-wave microseisms from storms have been tracked regularly, but the transverse S waves, which move much more slowly, have never been tied directly to a storm until now. Kiwamu Nishida from the University of Tokyo and Ryota Takagi of Tohoku University used a dense network of seismic detectors off the Japanese coast to measure S waves and pin their source to a storm off the coast of Greenland. Researchers should be able to learn about Earth's interior structure by comparing the propagation of S and P waves from the same storm.

August 25, 2016 3:24 PM

### Octopus-inspired robot flexes its muscles

NPR: A newly built soft-bodied robot looks like a baby octopus and can wiggle its legs when fed a common household chemical. The so-called octobot comprises a 1-mm-thick flexible silicone wafer set inside a molded soft body made of a squishy material. The wafer is crisscrossed with channels, like the conductive tracks on a computer circuit board, through which a 50% hydrogen peroxide solution flows. The hydrogen peroxide reacts with platinum in the channels to form oxygen gases, which expand and flow into the robot’s legs, causing them to flex. Although the octobot’s movements are restricted to wiggling extremities, the prototype serves as a proof of concept for more complex soft robots, which could serve various purposes such as squeezing into tight spaces.
August 25, 2016 2:28 PM

### Italy earthquake epicenter sits between those of two earlier quakes

Nature: The number of people killed by Wednesday’s magnitude 6.2 earthquake in Italy has now risen to 247. It is the strongest earthquake to strike Italy since the magnitude 6.3 quake in 2009 near the town of L’Aquila, which killed about 300 people. The epicenters of both quakes lie in Italy’s Apennine mountain range, a seismically active area because of a major fault system that extends the entire length of the range. Seismologists had been expecting a rupture in the area where yesterday's earthquake occurred because of its location between the epicenters of two earlier quakes, the one in 2009 and another that occurred in 1997. However, unlike in 2009, there were no precursor tremors that might have indicated that the larger quake was coming.
August 25, 2016 12:00 PM

### Proposed Anthropocene geological epoch starts in the late 1940s

Science: For the past seven years the Anthropocene Working Group has been trying to determine whether scientists should establish a new geologic epoch, one defined as the period in which humanity's presence is marked in sediments around the world. On 29 August the group will present its recommendations to the International Geological Congress and ask the International Commission on Stratigraphy (ICS), the organization that sets the demarcations of geologic time, to define the Anthropocene as a geologic epoch. The working group points to the period following World War II, dubbed the "Great Acceleration," in which fallout from nuclear testing, pollution from fossil fuels, and widespread production of plastic and aluminum left their mark in global sediments. The current epoch is the Holocene, which began around 9700 BCE. Before the working group formally presents the request to the ICS, geologists will collect sediment samples from around the world to demonstrate the global nature of humanity's impact.
August 25, 2016 11:45 AM

Ars Technica: In April, Russian billionaire and physicist Yuri Milner announced that he was providing $100 million for the research and development of an interstellar probe, a project he dubbed Breakthrough Starshot. The goal of the project is to accelerate tiny spacecraft up to 20% the speed of light so they could reach the closest star system, which includes Proxima Centauri and its newly discovered planet, in just 20 years. Now a team of researchers has calculated just how risky a trip at that speed would be. The scientists found that although heavier atoms in interstellar gas, such as oxygen, magnesium, and iron, could damage the vehicle, they would probably erode the ship's surface by only about 0.1 mm. However, interstellar dust would have a much more significant impact, eroding 1.5 mm of the spacecraft's surface and also causing localized melting as deep as 10 mm. The researchers say that much of the damage could be minimized or avoided by adjusting the spacecraft's design. August 24, 2016 3:50 PM ### Government research more independent under Obama, but not as much as hoped Nature: At his 2009 inauguration, President Obama pledged to "restore science to its rightful place" by reducing the amount of political intervention in government research. A review of his presidency suggests that although researchers have experienced less political pressure than they did during George W. Bush's administration, there have still been clear instances of meddling. For instance, in 2011, the Obama administration directed the Environmental Protection Agency to withdraw a plan to strengthen ozone pollution controls. The same year Health and Human Services secretary Kathleen Sebelius overruled the Food and Drug Administration's finding that the "Plan B One-Step" emergency contraceptive was safe to sell over the counter. In both cases, the agencies went forward with their plans despite the administration's objections. A recent survey by the Union of Concerned Scientists found that many scientists at federal research agencies believed their organizations were too often influenced by political concerns, even without overt efforts by the administration to direct agency projects and decisions. August 24, 2016 1:50 PM ### Proxima Centauri, closest star to the Sun, hosts a planet in the habitable zone The Kepler space telescope has uncovered a bounty of planets orbiting other stars, but many of those worlds are too distant for in-depth study. Now astronomers have discovered an exoplanet far closer to home—4.22 light-years, to be exact—and it's potentially habitable to boot. Proxima b, reported 24 August in Nature, sits in the liquid-water-friendly habitable zone of the red dwarf Proxima Centauri, the smallest of the three-star Alpha Centauri system and the star nearest to the Sun. From telescope data collected between 2000 and 2008, researchers picked out hints of a signal indicating that the star was wobbling with a velocity of about 1.38 m/s, potentially due to the gravitational tug of an orbiting planet. A dedicated observing run earlier this year by the European Southern Observatory's 3.6 m telescope at La Silla Observatory, Chile, confirmed the planet's presence. The radial velocity measurements reveal that the planet circles the star every 11.2 days, an orbit that puts the planet within Proxima Centauri's habitable zone, and has a mass at least 1.1 times that of Earth's. Although those parameters seem to suggest that Proxima b is both rocky and suitable for life, it's important to note that the planet's diameter, density, and precise mass are unknown. And astronomers are unsure whether life could thrive on red dwarf planets, since they are probably tidally locked and frequently doused in UV and x-ray radiation from stellar flares. Still, the fact that Earth's nearest stellar neighbor hosts a potentially habitable planet is a discovery worth celebrating. It's a moment astronomers had hoped for ever since the 2012 claim of a planet circling another star in the Alpha Centauri system was thrown in doubt after follow-up observations and analyses. The discovery should also provide a boost for the ambitious interstellar mission Breakthrough Starshot, which aims to launch high-speed miniature probes to the Alpha Centauri system. Although there are many obstacles to overcome for launching such a mission, Proxima b certainly represents an enticing target. Credit: Digitized Sky Survey 2; Davide De Martin/Mahdi Zamani Here are the best places to learn more about the discovery: The Washington Post has a nice roundup that emphasizes the limitations in our knowledge of whether Proxima b qualifies as "Earth-like." At Scientific American, Lee Billings, author of a book on exoplanets, details the discovery and adds helpful context. A New York Times visualization illustrates the location and orbit of Proxima b along with the radial velocity signal that led to the planet's discovery. Astronomer Abel Méndez at the University of Puerto Rico at Arecibo's Planetary Habitability Laboratory writes that by one measure Proxima b is the most similar exoplanet to Earth that we know, but that doesn't mean it's the most suitable for life. August 24, 2016 1:00 PM ### University of Kentucky to sue its student newspaper over sexual harassment case BuzzFeed: The University of Kentucky’s student newspaper, the Kentucky Kernel, is facing a legal wrangle with the university over the newspaper’s demands for the release of documents concerning a sexual harassment case involving a university professor. In December James Harwood, an associate professor of entomology, was charged with sexual assault and harassment against two students in his department. Two months later he was allowed to resign his position and avoid a disciplinary hearing. Because of the university’s refusal to provide the Kernel with information about the case, the paper appealed to the state’s attorney general, who ruled in the paper’s favor. Now university president Eli Capilouto says he plans to sue the paper to block the documents’ release. August 24, 2016 12:25 PM ### Pro-Stalin historian becomes Russia's minister of science Science: On 19 August, Russian president Vladimir Putin announced the appointment of Olga Vasilyeva to replace Dmitry Livanov as minister of science. Vasilyeva, a historian and expert on the Russian Orthodox Church, had been the head of the religious studies department at the Russian Presidential Academy of National Economy and Public Administration. She says her first goal in office is to examine organizational reforms that Livanov put into place, including the downsizing and reorganization of the Russian Academy of Sciences (RAS). Although some members of the RAS welcome Vasilyeva's appointment, citing her experience in the executive office, others are concerned about her lack of science training and her political views. Vasilyeva is perhaps best known for crediting Joseph Stalin with uniting Russia prior to World War II, and she has said that "the scale of Stalin's repressions has been exaggerated" in several public lectures. August 24, 2016 11:33 AM ### Magnitude 6.2 earthquake strikes central Italy BBC: Residents of Accumoli, Italy, and neighboring towns were awakened at 3:36 this morning local time when a magnitude 6.2 earthquake struck. The quake leveled many buildings not only in Accumoli, which was near the epicenter, but also in several neighboring towns, including Amatrice and Pescara del Tronto. At least 73 people have been reported killed, another 150 missing, and hundreds more injured. The area is known for earthquakes because it lies along a major fault line at the juncture of two tectonic plates, the African and Eurasian. In 2009 another town in the Apennines, L’Aquila, suffered a magnitude 6.3 quake, which killed hundreds of people and resulted in several scientists being charged with manslaughter for allegedly failing to adequately warn the public of the danger. Coincidentally, another earthquake, this one magnitude 6.8, struck today near Chauk, Myanmar. August 23, 2016 4:29 PM ### Quantum data locking demonstrated for the first time Science News: Proposed 10 years ago, quantum data locking is a method for encrypting information by encoding the entire message, not just the encryption key, in a quantum system. Now Daniel Lum of the University of Rochester in New York and his colleagues have demonstrated the technique for the first time. They defined the state of a photon as their message and then encrypted it by using an equation to scramble the photon's wave function. That ensured the photon would arrive at the intended location on the detector only if the receiver knew the same equation. Although the demonstration is an important step toward secure quantum communication, the technique may not be practical when applied to real-world messages. August 23, 2016 1:26 PM ### First US offshore wind farm prepares to go on line New York Times: Off the coast of Rhode Island, five wind turbines that make up the Block Island Wind Farm are being readied for testing in October. Although the project will generate only enough power for about 17 000 homes, it looks to be just the first of many offshore wind ventures as the US pushes for more renewable energy. Some 50 000 turbines are already running on land in the US, where they are cheaper and easier to build. However, ocean wind represents a much steadier, and so far untapped, resource, particularly for the US Northeast, where electrical demand and power rates are high. Unlike Europe, which has been operating offshore wind turbines for more than two decades, the US has been slow to adopt the technology. However, its success abroad may help speed its introduction to the US and bring down the initial costs of installation. August 23, 2016 12:47 PM ### NASA reconnects with Sun-orbiting spacecraft New Scientist: After two years of radio silence, NASA has announced that it has successfully reestablished contact with STEREO-B, one of a pair of spacecraft that have been orbiting the Sun since 2006. The mission of the Solar Terrestrial Relations Observatory (STEREO) has been the study of the Sun’s coronal mass ejections. The two spacecraft were so successful initially that the mission got extended several times. In 2014, however, as the spacecraft were about to pass to the far side of the Sun, NASA controllers lost contact with STEREO-B during a planned test of its computer reboot system. It is thought that the probe started spinning out of control, much like what happened to Japan’s Hitomi spacecraft. Although NASA has now managed to make contact with STEREO-B, scientists do not yet know whether the spacecraft will be able to resume normal operations. August 22, 2016 4:50 PM ### Bioluminescent jellyfish proteins used to produce low-energy laser New Scientist: To develop better and safer tools for use in biomedical imaging, researchers have worked with both conventional and polariton lasers. Neither has proven satisfactory because the first requires a lot of energy and the second, extremely low temperatures. Now Malte Gather of the University of St. Andrews in the UK and colleagues have overcome both problems by engineering a laser from the green fluorescent proteins found in jellyfish. The researchers placed a thin film of fluorescent protein between two mirrors and got it to fluoresce by shining blue light on it. The result is an organic polariton laser that could be embedded in living tissue and used to map and differentiate among thousands of types of cells. August 22, 2016 1:19 PM ### Higgs discovery prompts proposals for bigger, better particle experiments Nature: After the discovery of the Higgs boson in 2012 at the 27-km-circumference Large Hadron Collider (LHC), bigger and better facilities have been proposed to continue the search for new particles. Among them are the 31-km-long International Linear Collider to be built in Japan and two 50 km to 100 km circular colliders, one for protons and the other for electrons and positrons, in China. However, all will cost considerable money to build, and any one project could drain international funding from the others. A less expensive option, proposed by CERN’s director-general Fabiola Gianotti, would be to increase the power of the LHC by installing new superconducting magnets. Rather than turning to powerful colliders, some physicists are hoping novel experiments will lead to the discovery of new physics. The Deep Underground Neutrino Experiment under construction at Fermilab in Batavia, Illinois, will analyze neutrino oscillations and look for new types of neutrinos beyond the currently known three. August 22, 2016 12:43 PM ### US struggles to clean up after 2014 New Mexico nuclear accident Los Angeles Times: More than two years ago, a drum of nuclear waste exploded at the Waste Isolation Pilot Plant in Carlsbad, New Mexico. The explosion caused the facility massive long-term damage, which has stalled the shipment of thousands of tons of radioactive waste from US nuclear plants. The accident also led to the discovery of some two dozen safety lapses that had cropped up over 15 years of operation. The Department of Energy, which manages the site, has been slow to clean up but hopes to reopen the site for limited use by the end of the year. To meet its contractual obligations to dispose of waste from US nuclear weapons research and production, DOE has said the facility may have to stay open longer than planned or increase the amount of waste it accepts each year. August 22, 2016 12:35 PM ### NASA sets ambitious budget goals for Space Launch System Ars Technica: Since the end of the space shuttle era, NASA has been developing its next-generation launch vehicle. Called the Space Launch System, it is set to be the most powerful rocket ever built. It could also be the most expensive. Keeping costs down is “going to take some different thinking and maybe a little bit more risk taking,” said Bill Hill, NASA deputy associate administrator for exploration systems development, in an interview with Ars Technica. The goal, he says, is to keep production and operations costs to$2 billion or less, or roughly half NASA’s annual budget, so that the other half could be used to fund human missions to the Moon or Mars.
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