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 9 posts for the selected month (May 2015).
May 5, 2015 10:35 AM

Source of mysterious radio bursts found to be microwave ovens

Sydney Morning Herald: Fast radio bursts (FRBs) are millisecond-duration radio signals of extragalactic origin. Although some have been detected, many of them at the Parkes radio telescope in Australia, what causes them remains unknown. One possible source is a neutron star collapsing to a black hole. Since 2010, however, astronomers have been puzzled by the detection of similar radio bursts that were not coming from space but rather from Earth. Dubbed perytons, the brief events exhibit electromagnetic spectra similar to FRBs; in addition, both are emitted at 1.4 GHz, and both last about 250 milliseconds. Now Emily Petroff of Swinburne University of Technology in Australia and colleagues have solved the mystery: Perytons are emitted by microwave ovens being opened prematurely, before the timer pings. Although microwaves operate at a higher frequency of 2.3 –2.5 GHz, opening the door early causes the oven’s magnetrons to emit a radio burst at the lower, 1.4-GHz frequency before shutting down. Despite the mundane origin of perytons, the researchers say, FRBs remain “excellent candidates for genuine extragalactic transients.”
May 4, 2015 2:57 PM

Self-propelled microparticles now able to move upstream

Science: Two teams of researchers have developed separate mechanisms that allow microscopic particles to move against the flow of liquid. The first team, from New York University, used a micrometer-sized plastic sphere with an exposed area of iron oxide. When placed in a hydrogen peroxide solution and activated by blue wavelengths of light, the iron oxide splits oxygen away from the hydrogen peroxide molecules. The resulting electrical gradient is strong enough to push the microparticles against the flow of the solution in a small capillary. The second team, from the University of California, San Diego, used a similar chemical reaction to increase the catalytic effect of an effort to produce hydrogen gas for fuel cells. In a solution of sodium borohydride, platinum reacts strongly, producing hydrogen gas. However, the platinum molecules are quickly covered in hydrogen bubbles, which slow then stop the reaction. So the researchers created a two-piece microparticle, half platinum and half titanium. Because the bubbles are produced on only half of the microparticle, the ejection of hydrogen gas from that side pushes the microparticle away, and the reaction can continue. The resulting process is 20 times more effective than simply reacting platinum with sodium borohydride.

May 4, 2015 1:29 PM

Eruption provides first major test of Ocean Observatories Initiative

Nature: Real-time data from the 24 April eruption of the underwater Axial volcano were captured by a range of instruments in place off the Oregon coastline. The instrumentation, which included seismometers, pressure and temperature sensors, and a mass spectrometer, was put in place as part of the $386 million Ocean Observatories Initiative (OOI). The seismometers picked up a spike in activity on 23 April, which gave the OOI researchers time to prepare for the eruption. Unfortunately, the systems designed to provide full data to researchers outside of the initiative's monitoring organization were scheduled for completion in the next three months. The raw seismic data were live streamed outside of the OOI, but the rest of the data were recorded and will be provided in the next several days.

May 4, 2015 12:45 PM

The effects of radiation on long-duration astronauts

Los Angeles Times: Cosmic rays could pose a serious threat to the health of astronauts making long trips, such as to Mars. To simulate the potential damage, Charles Limoli of the University of California, Irvine, and colleagues exposed mice to radiation similar to that in space. After just six weeks, the animals’ memory and ability to learn were significantly affected. "Over the course of a two- to three-year mission, the damage would accumulate," said Limoli. Possible solutions could be helmets with advanced shielding or drug therapies. Limoli has already been exploring such drug therapies for cancer patients who have undergone radiation therapy.
May 4, 2015 11:30 AM

Global warming affecting Arctic sea ice and biodiversity

BBC: Arctic sea ice is changing, according to the Norwegian Polar Institute, which launched an expedition to gather data this past winter. Because of global warming, there is now less of the old, multiyear ice that stays frozen from one year to the next and more of the young, thin ice that melts in the summer. US scientists recently reported that Arctic sea ice is at its lowest winter levels since satellite records began in 1979. The Norwegian researchers are also studying the effects on animal populations living underneath the ice, such as crustaceans, amphipods, and copepods. While some will suffer because of the profound changes to their habitat, others will flourish in the increased sunlight. Any changes could have a cascading effect on the larger marine mammals higher up on the food chain.
May 1, 2015 12:15 PM

Blood-red water flow in Antarctica may simulate Mars-like conditions

Ars Technica: A unique feature in Antarctica has been the subject of a recent study by Jill Mikucki of the University of Tennessee, Knoxville, and colleagues. The researchers flew an electromagnetic transmitter over an area called Taylor Valley to search for the source of Blood Falls—an outflow of salty, iron-rich water that stains the nearby glacier with what looks like blood. By measuring the ground’s electrical resistivity, the researchers located two zones of super-salty groundwater. They propose that the water originated more than 10 million years ago, when the climate was warmer and sea levels were higher. At that time, the valley could have been filled with seawater. As atmospheric temperatures cooled, that seawater began to freeze. The water that did not freeze became saltier and soaked into the valley floor. The researchers say the conditions are such that the salty groundwater could be home to microbial life. If so, it could help researchers better understand harsh environments like those on Mars, where salty groundwater may also have once supported life.
May 1, 2015 12:10 PM

Tesla Motors expands its battery technology to solar power storage

New York Times: Electric-car manufacturer Tesla Motors is venturing into the solar power storage market with production of its Powerwall battery. Derived from the company’s Model S vehicle battery, the Powerwall is designed for home and industrial use and can store energy generated by solar panels. Not only can it provide power in the absence of sunlight, but it can also be used during general power outages or during peak times when utilities charge higher rates. According to Tesla CEO Elon Musk, the battery will cost $3500, and up to nine batteries can be connected to increase the amount of power that can be stored.
May 1, 2015 11:05 AM

Native Hawaiian panel rescinds support for telescope project

Science: The Office of Hawaiian Affairs (OHA), an advocacy group for native Hawaiians, has retracted its support for the construction of the Thirty-Meter Telescope (TMT) on Mauna Kea. The vote followed weeks of protests by native Hawaiians, who say the telescope would desecrate one of their most holy places and could greatly impact the fragile ecosystem there. If built, the TMT would be the world’s largest optical telescope. Mauna Kea is an ideal location for many reasons, including its low humidity and lack of cloud cover and atmospheric pollution. Its summit is already home to 13 other observatories. Although the OHA cannot prevent the telescope’s construction, its decision lands a symbolic blow against the project.
May 1, 2015 10:40 AM

MESSENGER spacecraft ends mission by colliding with Mercury

BBC: After four years orbiting Mercury, NASA’s MESSENGER spacecraft ran out of fuel and smashed into the planet yesterday about 3:30pm EDT. Because Mercury lacks an atmosphere, the craft would not have burned up on entry but rather collided with the surface at about 14 000 km/h. The impact would have destroyed the craft and left a crater the size of a tennis court. Although MESSENGER actually ran out of fuel several weeks ago, the venting of helium gas prolonged its ability to remain in orbit. MESSENGER was a highly successful mission, collecting more than 270 000 images and 10 terabytes of scientific measurements.
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Scitation: News Picks - Blog