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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 48 posts for the selected month (April 2015).
April 17, 2015 2:28 PM

Gravity mapping satellite provides clues for geothermal power

BBC: The European Space Agency's Gravity Field and Steady-State Ocean Circulation Explorer (GOCE) mapped Earth's gravitational field from 2009 to 2013. Now that map is being used to look for clues about the internal structure of Earth's crust. Subtle variations in gravitation can be evaluated to find the borders between rock formations and areas where the crust is thinnest, both of which are potential locations for geothermal activity. Such data have been used by geothermal prospectors before, but never at a global scale nor with the resolution that GOCE has provided.

April 17, 2015 2:13 PM

Norwegian fossils may be evidence of major extinction event

Science: There are currently five widely accepted major extinction events. New evidence collected by David Bond of the University of Hull in the UK and his colleagues suggests a sixth event may be added to that list. Occurring 260 million years ago, the extinction marks the end of the Capitanian age. Initial evidence for the extinction event was found in China in the early 1990s. Fossils of foraminifera and brachiopods were found in rocks formed in an ancient tropical sea. But, according to the rock record, they suddenly disappeared. A similar extinction of brachiopods has now been found by Bond's team in rocks on an island in Norway. The researchers connected the two events by comparing isotope levels, which showed similar variations. The finding suggests that global-scale changes occurred in ocean chemistry. However, because the dating of the event in Norway has not yet been verified, that extinction could have been a separate, regional event.

April 17, 2015 1:00 PM

Warm-water anomaly in NE Pacific affecting weather and marine animals

New Scientist: An extensive “blob” of warm water—some 2000 km wide and 100 m deep—has been lingering off the US Pacific coast for the past year and a half. Between 1 °C and 4 °C warmer than normal, the blob has been affecting water circulation, inland weather, and ocean ecosystems. Researchers studying the anomaly through the use of satellite imagery say it may have been caused by an “unusually strong and persistent” weather pattern that deflected winds and prevented the natural mixing of cooler air and water from high latitudes. Of most concern to scientists is the impact on marine species, which are being forced to adjust to new habitats and feeding patterns.
April 17, 2015 12:00 PM

How deep brain stimulation relieves Parkinson’s symptoms

New York Times: For more than a decade, deep brain stimulation (DBS) has been used to treat patients with Parkinson’s disease. In DBS, electrodes implanted in the patient’s brain act as a sort of pacemaker to send electrical impulses to specific parts of the brain and help restore a person’s ability to control his or her movements. Why the treatment is effective, however, was not entirely understood. To find out, Philip Starr of the University of California, San Francisco, and his colleagues conducted a series of experiments in which they added a strip of sensors to the motor cortex of DBS patients and then studied the signals emitted by the brain’s neurons. Parkinson’s disease appears to affect the brain's beta rhythms by causing them to become so tightly synchronized that the brain’s motor cortex becomes phase locked. DBS disrupts that oversynchronization, allowing the motor cortex to function normally. The researchers say that although the finding is important, Parkinson's is a complicated disease and DBS relieves just some of its symptoms. DBS could, however, be used to treat other conditions as well, including depression and obsessive compulsive disorder.
April 16, 2015 3:14 PM

Four-galaxy collision provides possible hint of dark matter interactions

BBC: The existence of dark matter has been established through observations of the effect its mass has on normal matter and on light via gravitational lensing. However, observations of dark matter have not provided any other clues about how it interacts with normal matter or itself other than through gravitation. Now, Richard Massey of Durham University in the UK and his colleagues say they may have found evidence of dark matter interacting with itself. They used gravitational lensing to examine a four-galaxy collision in the Abell 3827 cluster 1.4 billion light-years away. It appears that the dark matter surrounding one of the galaxies is lagging behind the rest of the matter in that galaxy. Massey's group has studied other galactic collisions and not seen such a phenomenon. They admit that they have not ruled out all possible known astrophysical sources for the new discrepancy, and they intend to create models of the system to do so.

April 16, 2015 1:47 PM

Earth's magnetic field may be result of impact with Mercury-like body

Los Angeles Times: The general theory for the formation of Earth is that it is a conglomeration of rocky objects like those currently in the asteroid belt. By itself, that theory doesn't explain why there are enough radioactive elements in Earth's core to provide the energy for driving the planet's magnetic field. Those elements like to bond with oxides, and the combined molecules would be light enough to move out of Earth's core. Now, Bernard Wood and Anke Wohlers of the University of Oxford in the UK propose an answer. They modeled a high-pressure environment where radioactive elements were mixed with oxygen-lacking sulfur compounds. The radioactive elements strongly bonded with the sulfur-rich metals and created compounds heavy enough to stay in the core. However, Earth is rich in oxides and poor in sulfides. To have had enough sulfides to establish a magnetic field, early Earth would have to have been impacted by a body rich in sulfides, much like Mercury, but with the mass of Mars. That same impact may have also given birth to the Moon.

April 16, 2015 1:25 PM

US House committee proposes reauthorization of America COMPETES Act

Science: Yesterday Lamar Smith (R-TX), chairman of the US House Committee on Science, Space, and Technology, introduced legislation designed to reshape federal research policy. Called the America COMPETES Reauthorization Act of 2015, it includes suggested spending levels for several government agencies and changes to many current policies. Because none of the committee's Democratic members were consulted nor sponsored the bill, some of its provisions are expected to provoke controversy when the committee meets to discuss it next week. In their Science article, Jeffrey Mervis and David Malakoff summarize some of the bill’s key points.
April 16, 2015 12:00 PM

Medical 3D printing among topics explored at NY conference

Nature: Three-dimensional printing technology is increasingly being used by medical professionals for creating replacement body parts. Titanium hip joints, plastic tracheal splints, and prosthetic hands have already been printed and successfully implanted in human patients. Now researchers are working to 3D-print entire organs by using cells as ink. The latest developments in medical bioprinting are among the topics being discussed this week at the third annual Inside 3D Printing conference in New York. One of the items on the agenda is a prototype ear that combines a hydrogel frame and nanoelectronics with biological tissue. Because internal organs, such as livers and kidneys, are so complex, however, efforts to reproduce them are still in the early stages, and some people in the field doubt that they can ever be achieved.
April 15, 2015 2:10 PM

Isolating cancer cells with acoustic waves

Ars Technica: Cancerous tumors can shed cells that travel through the bloodstream and act as seeds to spread the cancer to other parts of the body. To isolate and study such circulating tumor cells (CTCs), various methods have been tried. However, most have proven unsatisfactory because they either require invasive biopsies or destroy the CTCs. Now researchers have found a way to separate CTCs from healthy blood cells by using sound waves. A blood sample is sent flowing through an acoustic wave field, in which transducers create pairs of pressure nodes and antinodes that are tilted relative to the direction of fluid flow. The so-called “tilted-angle standing surface acoustic waves” apply different forces to different types of cells, which affects their trajectories. Using the method, the researchers say they were able to separate a variety of cancerous cells from healthy white blood cells "with a recovery rate better than 83%." More study is needed, however, before the device is ready for clinical use.
April 15, 2015 9:33 AM

United Launch Alliance announces new Vulcan reusable rocket

New Scientist: United Launch Alliance (ULA) is the partnership between Boeing and Lockheed Martin that is currently responsible for all Atlas and Delta rocket launches. On Monday, the partnership announced that its next generation of rockets, called Vulcan, will be reusable, similar to competitor SpaceX's Falcon 9. Vulcan's first launch is scheduled for 2019, at a cost of just $100 million. In comparison, the companies' current rockets cost an average of $225 million per launch. To reduce ULA's dependence on Russian RD-180 engines, Vulcan's engines will be produced by either Blue Origin or Aerojet Rocketdyne. Instead of attempting to land its used booster engines on an ocean barge as SpaceX has done, ULA says that its  engines will deploy parachutes and then be caught by helicopters.

April 15, 2015 9:31 AM

Dark matter mapped in an area covering 2 million galaxies

Nature: Dark matter, the material that makes up the majority of the mass of the universe, has been mapped in small regions around galaxies many times. Now, Chihway Chang of the Swiss Federal Institute of Technology in Zurich and his colleagues have mapped dark matter in an area of the southern sky that is roughly equal to the angular area of 700 Suns. As part of the Dark Energy Survey (DES), Chang's team used the 570-megapixel camera of the Victor M. Blanco telescope at the Cerro Tololo Inter-American Observatory in Chile to map the way that dark matter bends galactic light. The variations in the light from the most distant objects revealed the presence of dark matter in the intervening spaces. The resulting map of dark matter compares favorably with other maps of the universe's underlying structure. This is the first data presented from DES and constitutes only 3% of the area that the survey is planned to cover by the time it is complete in 2018.

April 15, 2015 9:25 AM

Women preferred over men for faculty STEM jobs, says study

Science: Female applicants for science, technology, engineering, and mathematics (STEM) academic jobs are preferred two to one over identically qualified males, according to a new study. The findings are based on an exercise in which researchers invented hypothetical candidates for an assistant professorship and asked more than 800 tenure-track faculty members in STEM fields to rank them. The fictional candidates were provided with a job application summary and with personal information, such as whether they were married, had a working spouse, or had children. Overall, among equally qualified women and men, the women were much more likely to be hired. Critics point out, however, that the survey doesn't take into account the many factors involved in real-world hiring decisions and doesn't address the higher attrition rates of women once they've attained STEM positions.
April 14, 2015 1:35 PM

Rosetta mission indicates comet 67P is not magnetic

BBC: Tiny grains of magnetic materials in meteorites have led researchers to propose that in the early universe, magnetic fields may have helped dust in the protoplanetary disk to accrete and form larger bodies. But how much accretion was due to magnetism and how much to gravity or other forces has been unknown. Because comets may provide clues to the role of magnetic fields in the formation of larger solar-system bodies, the European Space Agency sent the Rosetta spacecraft to get a closer look at one—comet 67P/Churyumov–Gerasimenko. Last year Rosetta deployed a lander to the comet’s surface and collected magnetic field measurements from above and along the surface as the lander bounced several times before coming to a stop. From those data, researchers were able to determine that the comet has no internal magnetic field of its own. If the comet is indicative of most, then forces other than magnetism must have been responsible for the origin and evolution of larger planetary bodies, they conclude.
April 13, 2015 2:05 PM

Grouping female engineering students together boosts their confidence

Ars Technica: Women engineering students have higher levels of motivation, participation, and confidence when they are in groups composed mostly of other women than when they are in groups composed mostly of men or of equal numbers of men and women, according to a study published in the Proceedings of the National Academy of Sciences. The finding is important because of the gender imbalance that exists in science, technology, engineering, and mathematics (STEM) fields. Fewer women pursue jobs in STEM fields than men, and women in STEM fields are more likely to leave than their male contemporaries. Isolation and gender stereotypes may be to blame, say the researchers. The current study was based on 122 female undergraduate engineering majors at a large public university.
April 13, 2015 1:37 PM

"Patent troll" bill spurs dissent between universities and industry

Science: Patent trolls are companies that buy up the rights to a variety of patents and then pursue lawsuits against other companies over potential infringements of the patents. A bill introduced in the US House of Representatives in February is intended to make it more difficult for such companies to profit. Many companies in the electronics and high-tech industries support the bill. Universities, however, are grouping together to oppose it out of fear that it may hinder their ability to defend their own patent rights. American universities often gain patents based on the work of the professors and researchers they employ. Instead of then producing those inventions, the universities license the patent rights and often file lawsuits over infringements. Several university groups and a technology industry group have exchanged public letters calling for changes in stances or alternatives to the bill under discussion. However, the bill appears to have strong support in both the House and Senate.

April 13, 2015 1:15 PM

New technique may provide better port screening for nuclear materials

Nature: Cargo containers that enter a country's ports are inspected for a variety of illegal goods, including nuclear materials. However, it is relatively easy to shield nuclear materials from detectors that are passively looking for emitted radiation. An active option for penetrating shielding uses gamma rays to create images of the materials inside containers. The screening technique exploits the fact that high-Z elements absorb high-energy gamma rays more readily than low-Z elements do. Using a broad-spectrum source to generate the gamma rays would require levels of radiation that are dangerous to the people in the area, including port employees, stowaways, and human trafficking victims hidden inside cargo containers. Now Areg Danagoulian of MIT and his colleagues have developed a variant of this technique that reduces the danger by using just two gamma-ray wavelengths, 4.4 MeV and 15.1 MeV. The two wavelengths have been shown to clearly distinguish between types of metals based on their elemental weights. This means that uranium or plutonium, which are both much heavier than most nonnuclear metals, would appear as distinct from lead or iron. So far, Danagoulian's team has demonstrated the technique's capabilities only with nonnuclear materials.

April 13, 2015 11:40 AM

Using smart phones to crowdsource earthquake detection

Los Angeles Times: Even a few seconds’ warning of an impending earthquake could be enough to allow people to prepare. Although an earthquake early-warning system is already being designed for California, such systems have proven prohibitively expensive to build and maintain. Instead, Thomas Heaton of Caltech and his colleagues propose taking advantage of the ubiquitousness of smart phones and their GPS functionality to create a low-cost alternative. The system would use the ability of the phones' internal accelerometers to detect movement. According to the researchers, the difficult part was distinguishing between actual earthquake activity and the day-to-day jostling a phone undergoes through normal use. They tested their system using data from the 2011 Tohoku earthquake and found that if at least 103 phones registered the same amount of surface displacement at the same time, it was likely an earthquake had occurred. Next the researchers plan to test their system under real-world conditions in Chile.
April 10, 2015 1:45 PM

New species of prehistoric bird found in Argentina

BBC: The most complete skeleton discovered so far of a prehistoric “terror bird” has been uncovered in Argentina. Terror birds, which were carnivorous and flightless, stood up to 3 m tall and had huge skulls, large hooked beaks, and long hind limbs. They lived primarily in South America, about 62 million to 3.5 million years ago. The newly discovered specimen represents a new species, which has been called Llallawavis scagliali, after one of the discoverers, Fernando Scaglia. The skeleton is 90% complete. Because its skull was well preserved, researchers have been able to reconstruct the shape of its inner ear and thus determine some of the bird’s sensory capabilities. They say that its apparent sensitivity to low-pitched sounds probably indicates it also produced low-pitched sounds.
April 10, 2015 1:15 PM

Scientific details are part of the challenge in finalizing Iran nuclear deal

Nature: The nuclear "deal" agreed to by Iran and six nations led by the US is less a deal and more a framework for a potential deal that has a deadline of 30 June. Many of the key points in the framework hinge on science. Perhaps the easiest is the goal of reducing Iran's ability to switch from civilian nuclear production to military production. Known as the "break-out" process, it depends on the nation's quantity of low-enriched uranium reserves and the number of centrifuges it possesses capable of further enrichment. The framework reduces both and also calls for a change in the fuel used at one of Iran's reactors that currently produces plutonium waste. The framework also calls for increased inspections of Iran's nuclear facilities, supplemented by remote sensing using satellites and other technologies. The final deal may establish long-term safeguards and inspections similar to those in place for Brazil and Japan. One of the most challenging issues for the deal may be determining what nuclear weapon development Iran has done in the past and may still be working on. Such determinations probably can't be made unless highly trained nuclear weapons engineering experts are allowed access to Iran's nuclear research facilities.
April 10, 2015 1:10 PM

Land bridge between North and South America older than thought

Ars Technica: Exactly how many millions of years ago the continents of North and South America became joined by the Isthmus of Panama has been difficult to determine. Previous estimates have been based on such factors as fossil evidence of species migrating between the two continents and changes in the Caribbean Sea’s salinity. To fine-tune the timeline, Camilo Montes of the University of Los Andes and colleagues studied grains of the mineral zircon embedded in igneous rock in Panama and neighboring Colombia. Zircon is incredibly durable and contains trace amounts of uranium, which can be used for radiometric dating. The researchers found that while the igneous rock, and hence the zircon, in Colombia were much older than those in Panama, there was evidence of Panamanian zircon embedded in younger sedimentary rock in Colombia. They propose that as the two countries joined up, rivers carried sediment from Panama to Colombia. What was surprising was that the flow appears to have started about 14 million years ago—some 10 million years earlier than previous estimates for the joining of the two continents.
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