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Updated: 1 hour 8 min ago

El Niño helping to return Sierra Nevada to its normal snowy state

19 February 2016
Los Angeles Times: Although California has been experiencing a major drought over the past several years, relief may be in sight. This year several early winter storms, strengthened by El Niño conditions in the Pacific Ocean, blanketed the Sierra Nevada with heavy snow. The snowpack is 94% of normal for this time of year, compared with 5% last year, which was the lowest in 500 years. David Rizzardo of the California Department of Water Resources and coworkers have been monitoring the amount of precipitation in the mountains with automated snow sensors and manual measurements. Tracking the snowpack is important not just to local officials, environmentalists, and recreation-based businesses but also to the entire state: Runoff from the mountains helps fill major reservoirs.

The Laser Interferometer Gravitational-Wave Observatory contributes a physics sound bite for the ages

19 February 2016
Media worldwide celebrate LIGO's "fleeting chirp" confirming "the last prediction of Einstein's general theory of relativity."

LIGO-India gets governmental go-ahead

18 February 2016
Indian Express: Gravitational-wave enthusiasts have another reason to celebrate. India's Union Cabinet has given what it calls in-principle approval to build a gravitational-wave observatory in the country. The announcement comes less than a week after scientists with the Laser Interferometer Gravitational-Wave Observatory (LIGO) reported the first-ever direct detection of gravitational radiation. An observatory in India would give LIGO a third detector (the others are in Louisiana and Washington State) to detect gravitational waves and triangulate the position of sources in the sky. Italy's Virgo, Germany's GEO600, and the KAGRA detector under construction in Japan would join LIGO's detector trio in a global network.

Ellis Wilson Miller

18 February 2016

2D tin oxide semiconductor developed for use in transistors

18 February 2016
IEEE Spectrum: The development of two-dimensional alternatives for silicon transistors has been held up because all the 2D semiconductors to date have been n-type, electron-carrying materials. A p-type (positive charge–carrying) material is also required. Now researchers have used laser deposition to mate a 2D tin oxide layer with a sapphire and silicon dioxide substrate to achieve the first stable p-type semiconductor. With the new material, the scientists fabricated several field-effect transistors. The next step will be to use the new p-type semiconductor to build a complementary metal oxide semiconductor. Ultimately, researchers hope to create 2D semiconductors that transport electricity and heat more efficiently than does silicon.

Dearth of near-Sun asteroids may be due to thermal forces

18 February 2016
Los Angeles Times: Although asteroids can be found throughout the solar system, fewer than expected have been found within 10 solar diameters of the Sun, according to a new study published in Nature. Robert Jedicke, of the University of Hawaii Institute for Astronomy, and colleagues noticed the asteroid scarcity while working on a map of of near-Earth objects. They also found that asteroids near the Sun tend to have bright surfaces. Jedicke and his team propose that many asteroids in the region have succumbed to the Sun's intense heat and radiation. Dark surfaces absorb more heat, which could trigger cracking or the explosion of volatile elements. Alternatively, solar radiation could speed up the asteroids' rotation so much that the rocks break apart. Whatever the reason for the disappearing asteroids, the study could yield insight into their composition and internal structure.

Circuit-enhanced spin flips

18 February 2016
Reducing the radiative transition’s time constant from thousands of years to a fraction of a second could benefit quantum information schemes.

Winged snails “fly” through water

18 February 2016
New Scientist: Most zooplankton use their appendages to paddle through the water by way of drag-based propulsion, similar to the way humans use oars to row a boat. Now a species of sea snail, Limacina helicina, has been seen to use its wing-like appendages to propel itself with lift. To watch the so-called sea butterflies in action, David Murphy of the Johns Hopkins University and colleagues set up high-speed cameras in a tank of water. The video shows the creatures bringing their wings together and then quickly pushing them apart in a flapping motion like that of a fruit fly. Although such lift-based swimming is common in larger aquatic animals such as sea turtles, the researchers say it was unexpected for animals on the scale of zooplankton. The finding illustrates an evolutionary convergence of locomotion techniques for insects and gastropods.

Steven Detweiler

17 February 2016

Roger Peverley

17 February 2016

Human development near rivers is exacerbating flooding

17 February 2016
Ars Technica: Floods are worse now than they were decades ago because of human management. So say researchers from Washington University in St. Louis, who compared last year's record-setting flood on the Meramec River with the previous record holder, which took place in 1982. Robert Criss and Mingming Luo predicted the amount of flooding that should have occurred in 2015 based on rainfall and found that the actual flooding exceeded their prediction. They attribute the rise to the increased number of levees and other structures that manipulate the river system. Had the 1982 storm occurred over the 2015 landscape, the researchers say, the flooding would have been much worse and caused more damage. Criss and Luo recommend avoiding new commercial and residential development in floodplain areas.

Driving restriction in New Delhi helps temporarily reduce pollution

17 February 2016
Nature: New Delhi, India, has some of the worst traffic and pollution in the world. To try to address both problems, the city government held a 15-day trial in January to restrict the number of cars on the road. It asked that owners of private vehicles drive only on alternate days by following an odd–even rule, depending on the last digit of their license plate number. Scientists monitoring the experiment found it temporarily reduced not only the number of vehicles but also the daily amount of fine particulate matter in the air, which dropped by 10–13%. Those particles can cause major health problems, such as lung cancer, asthma, and cardiovascular and respiratory diseases. Because of the initial success and cooperation of drivers, the government is considering repeating the experiment in April.

There may be more meteorites in Antarctica than meet the eye

17 February 2016
Smithsonian: Because of its vast expanses of snow-white terrain, Antarctica is one of the best places to look for meteorites. The upward flow of the ice moves meteorites to the surface and concentrates them in areas called meteorite-stranding zones. However, only a small percentage of those meteorites contain iron. In a recent study, Geoffrey Evatt of the University of Manchester and colleagues propose that it may take a little digging to find those iron meteorites. Through a combination of calculations and experiment, the researchers concluded that iron meteorites conduct heat from the Sun toward the ice below, causing the ice to melt and the meteorites to sink. Ground-penetrating radar or other advanced technology may be needed to find those elusive extraterrestrial visitors.

Material developed to be invisible to certain electromagnetic signals

17 February 2016
IEEE Spectrum: Putting a new spin on the idea of an invisibility cloak, researchers at MIT and Zhejiang University in China have created a sheet of metallic mesh that is invisible to certain wavelengths of light. The sheet consists of an array of copper—tiny cubes connected by thin, square-shaped rods—sandwiched between two panels of a dielectric material called polysulfone. The resulting material allows microwaves with a specific wavelength to pass through without scattering. Such an invisible mesh could lead to antenna-protecting radomes that selectively allow certain radar signals to pass through while screening out others.

Sea levels not rising as quickly as expected

16 February 2016

Los Angeles Times: Despite the melting of glaciers and ice sheets over the past decade and a half, sea levels have not risen as much as expected. According to scientists at NASA’s Jet Propulsion Laboratory, the difference is due to the amount of moisture being absorbed by the continents. Using the Gravity Recovery and Climate Experiment (GRACE), which comprises two satellites nicknamed Tom and Jerry, John Reager and coworkers studied how the distribution of water causes the force of Earth’s gravity to wax and wane at various points on the planet’s surface. Drought in California, for instance, causes a decrease in gravity; a big flood elsewhere will increase the force of gravity. Because of an increase in rain and snowfall over land during the period 2002–2014, the continents have soaked up more water and thus have caused the rate of sea-level rise to slow. However, land can only absorb so much water. Humans will still need to cut their greenhouse gas emissions to slow glacial melt and concomitant sea-level rise.

Questions and answers with Mary K. Gaillard

16 February 2016
The trailblazing female physicist recounts scientific accomplishments and painful memories of discrimination in telling her story, which she says has a happy ending.

Another neutrino detector sees neutrino flavor deficit

16 February 2016

Ars Technica: China's Daya Bay neutrino detector analyzes a beam of electron antineutrinos produced by nearby nuclear reactors. The detector counts how many of the particles have experienced flavor oscillation and become either muon or tau antineutrinos. After nearly eight months of operation, the facility has detected more than 300 000 neutrinos. However, the number of flavor oscillations has not matched what scientists predicted, and this is not the first detector to note the discrepancy. But none of the experiments have had a strong enough—5 sigma—signal to conclude outright that the discrepancy is real. One theory suggests that there are flavor-neutral, or "sterile," neutrinos. Perhaps on a related note, Daya Bay also saw an unexpectedly large, though also not quite 5 sigma, signal in the energy level of the neutrinos. If that signal proves to be real, it could mean that nuclear reactors aren't producing as many neutrinos as expected.

Ability to detect gravitational waves opens new window on the cosmos

16 February 2016
Christian Science Monitor: The first direct observation of a gravitational wave, which was announced on 11 February, has opened up a new field of astronomy, writes Calla Cofield for the Christian Science Monitor. Through the use of the Laser Interferometer Gravitational-Wave Observatory (LIGO) and more powerful instruments in the future, scientists will be able to study aspects of the universe that have been undetectable by optical telescopes or any of the other instruments developed over the past century to study different wavelengths of light, such as x rays, radio waves, UV waves, and gamma rays. Cofield discusses the importance of gravitational waves to the future of astronomy and their potential for shedding new light on such objects as black holes, supernovas, and neutron stars.

China displaces 9000 residents to build world's largest radio telescope

16 February 2016

Guardian: Construction of the Five Hundred Meter Aperture Spherical Telescope (FAST) started five years ago in the Chinese province of Guizhou and is expected to be completed by September. The telescope's diameter is 200 m larger than that of the Arecibo telescope, which turned 50 in 2013. To ensure minimal signal interference for the 1.2 billion yuan ($184 million) project, the Chinese government has decided to relocate more than 9000 residents from an area within a 5 km radius around the telescope, and it is providing each resident with 12 000 yuan ($1800) in compensation.

Is a US “renewables revolution” really “toppling” fossil fuels?

16 February 2016
Enthusiasm for good news has led a few reporters to scant important quantification.

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