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Updated: 1 week 8 hours ago

Young crust in subduction zone under Cascades produces unusual magma

23 April 2015

Ars Technica: Subduction zones occur where oceanic crust is forced down under continental crust. As the subducted material is pushed toward the mantle, it melts into magma. The amount of water present in the different layers of the rock affects how quickly pockets of magma form. Rock that formed more recently is still warm, which means that it doesn't have to descend as far down into the mantle to start heating up and become dehydrated. Kristina Walowski of the University of Oregon and her colleagues, who have collected minerals from volcanos in the southern region of the Cascades, have confirmed that the subducted plate there is quite young. However, a simulation based on the isotopes in the minerals suggests that the water escaped the rock well before it reached the depth at which magma forms. That led Walowski's team to adjust the model to incorporate water trapped at the bottom layer of the crust. That reservoir of water leads to the formation of magma, and the ratios of other elements in the minerals in the Cascades support the idea that a young oceanic plate is being turned into magma there.

Diving bird runs on water to attract a mate

23 April 2015
Science: Few vertebrates have the ability to defy gravity by running across the surface of water. One species that has managed the feat is the grebe, a type of freshwater diving bird that lives in western North America. For both the western and Clark’s grebes, “rushing” for brief periods of up to seven seconds is used as a courting display. But until recently, researchers did not know exactly how grebes, which can weigh up to about 2 kg, manage to skim across the water. In May 2012 Glenna Clifton of Harvard University and her colleagues spent a month in the field, where they managed to capture high-speed video of the novel display. From that footage, the researchers have determined that the grebes are able to slap their feet rapidly against the water’s surface, as many as 20 times per second. However, the force generated is just half that needed to keep them up. To determine how they generate the rest of the force may require filming under the water.

Measuring ionization potential one atom at a time

23 April 2015
Researchers in Japan have begun probing the atomic physics of elements that can be produced only in minute quantities.

Wisconsin state agency hit with official Florida-like climate-change taboo

23 April 2015
Chicago Tribune headline says, “Daughter of Earth Day founder banned from global warming work in Wisconsin.”

Radio waves detected from individual electrons

22 April 2015
Science: Charged particles traveling through magnetic fields are deflected from their linear paths and instead follow curved trajectories. In doing so, they release radiation. For the first time, researchers have detected the radio waves of a single electron trapped in a spiral in a strong magnetic field. To achieve this, a team of scientists at the University of Washington in Seattle trapped krypton-83 gas produced by the decay of rubidium-83. When trapped, each krypton atom ejected a single electron with a known energy. The electrons were piped into a waveguide cell in the presence of a superconducting magnet. The waveguide was designed to detect electromagnetic radiation between 25 GHz and 27 GHz and transmit the radiation to amplifiers. That allowed the researchers to track the change in frequency of the emissions of individual electrons as they lost energy and spiraled inward. The technique provides researchers with a new method for measuring the energy of electrons in a nondestructive manner. It may also be useful for calculating the mass of neutrinos by using electrons emitted from tritium atoms via beta decay.

<em>Hubble</em> spots mysterious exploding star

22 April 2015
Nature: A mysterious stellar outburst has been captured by NASA’s Hubble Space Telescope. Images taken in January and August 2014 reveal what appears to be an exploding star in the constellation Eridanus. The explosion's brightness was 100 times greater than that of an ordinary nova yet 10 times fainter than that of a supernova. One possible explanation is that the outburst was a kilonova, which occurs when two neutron stars collide. However, none of the high-energy radiation that is typically emitted by such events was observed. Another possibility is that the explosion represents an entirely new class of celestial objects. If so, it is hoped that future telescopes with much wider fields of view, such as the Large Synoptic Survey Telescope and the Wide-Field Infrared Survey Telescope, may find more of them.

New atomic clock sensitive to altitude change of just 2 cm

22 April 2015
Los Angeles Times: The connection between time and gravity was made 100 years ago by Albert Einstein. As ever more precise clocks have been developed, researchers have been able to demonstrate the effects of time dilation by comparing the speed of clocks located at different altitudes—in satellites separated by miles, in an airplane and on the ground, on top of a mountain and at sea level, and even just one foot apart. Now, Jun Ye of JILA and his colleagues have developed an atomic clock sensitive enough to show the effect of gravity when the clock is moved just 2 cm up or down. The new clock, which is a version of an optical lattice, uses a laser to measure the movement of an electron in orbit around a strontium nucleus. To improve on previous optical lattice clocks, Ye's team used highly sensitive thermometers and one of the most stable lasers available. They also were able to reduce the disruptive effects of the laser on the electron. The result is a clock three times more sensitive than the previous best clock and several orders of magnitude more sensitive than the world's official time-keeping atomic clock.

Japanese maglev train sets another world speed record

22 April 2015
BBC: In a recent test, Japan’s magnetic levitation, or maglev, train attained a record speed of 603 km/h. The test lasted 10.8 seconds, during which the train traveled 1.8 km along an experimental track. It broke its own record from last week of 590 km/h. Maglev trains use electromagnets to provide both levitation above and propulsion along a special guideway. Japan plans for the trains to begin commercial service in 2027. The first line would connect Tokyo and Nagoya, a distance of about 280 km. The maglev trains will cut the travel time in half of that attained by Japan’s Shinkansen, a high-speed train that has been providing service for the past half century. During a visit to the US later this month, Japanese prime minister Shinzo Abe is expected to promote building a maglev system between New York and Washington, DC.

Cyclonic circulation development during extreme precipitation

21 April 2015
A numerical study reveals that vortex formation played a crucial role in the floods that devastated towns on Colorado’s Front Range.

Cold spot in cosmic microwave background was caused by "supervoid"

21 April 2015
Wired: Several of the maps of the cosmic microwave background (CMB) radiation have revealed a spot that is unusually large and cold. Its size and coldness have posed a challenge to theories of the universe's early history. Now Istvan Szapudi of the University of Hawaii and his colleagues believe they have an explanation that fits with other cosmological theories. Using the Pan-STARRS1 telescope and NASA's Wide-Field Infrared Survey Explorer, Szapudi's team found a vast region of space with a much lower density of galaxies than average, about 1.8 billion light-years wide and located just 3 billion light-years from Earth. They propose that as the CMB radiation passed through that "supervoid," it may have lost considerable energy, which explains why there is a cold spot.

Most accurate simulations of colliding black holes yet

21 April 2015
Nature: Modeling collisions of black holes is extremely complex. Most simulations simplify various parts of the systems, including the application of general relativity. Now Stuart Shapiro of the University of Illinois at Urbana-Champaign and his colleagues have developed a model that fully incorporates general relativity, allowing for the most in-depth three-dimensional rendering of black hole collisions yet. Shapiro's team was able to couple Einstein's equations with the equations that represent the motion of matter moving at a large fraction of the speed of light in a magnetic field. The new simulations are well-timed because recent observations suggest that the two black holes assumed to be present in the system PSO J334.2028+01.4075 are likely to merge in the next seven years.

European Parliament opposes plan to divert funds from Horizon 2020

21 April 2015
Science: At the end of last year, European Commission president Jean-Claude Juncker proposed diverting €2.7 billion from Horizon 2020—the European Union’s €70 billion, seven-year research funding program—and using it for a new investment fund to boost Europe’s economy. Although supported by the EU member states, the plan sparked opposition from various research organizations. In February a group of Nobel laureates addressed a letter to Juncker, asking him to reverse what they called a “misguided and short sighted policy.” Now the European Parliament has also voiced its opposition to the plan. Negotiations among the three principals—the commission, parliament, and member states—are set to begin on 23 April.

Ocean acidification may be shrinking shellfish, says study

21 April 2015
New Scientist: Not only are the oceans growing more acidic due to increasing levels of atmospheric carbon dioxide, but marine life is being forced to adapt or risk extinction. Richard Twitchett of London’s Natural History Museum and colleagues studied two species of sea snail living in the Mediterranean near volcanic seeps, where injections of CO2 make the water more acidic. They found that the snails living there are about two-thirds the size of those living in water with normal pH. Although the researchers were surprised to find that the smaller snails consumed twice as much oxygen per milligram of tissue as larger snails, their total oxygen consumption was half that of larger snails. That adaptation makes them better able to survive in more acidic environments. The researchers say the dwarfing of marine species due to global warming could have serious consequences for humans who depend on them for food.

Has Moore’s Law generated Moore’s Era?

20 April 2015
Journalists and commentators examine five decades of computational progress—and ponder what might be coming.

German politicians agree to €5 billion extension of science funding

20 April 2015

Nature: A deal between Germany's ruling political parties would provide €5 billion ($5.4 billion) to extend the nation's Excellence Initiative until 2028. Currently set to expire in 2017, the initiative provides funding to the nation's top-performing universities and early-career researchers. Since 2006, the initiative has created 20 000 new science jobs. The details of the funding have not been finalized, but are expected to be released in January after a review of the performance of the initiative so far.

New fermentation method increases hydrogen production

20 April 2015

MIT Technology Review: Normal fermentation processes rely on microorganisms, which produce enzymes that convert sugars into usable products, among them hydrogen gas for fuel cells. Now, Percival Zhang of Virginia Tech and his colleagues have developed a hydrogen creation technique that uses enzymes alone. In the group's experiments, the technique produced three times as much hydrogen as did conventional fermentation. Their demonstration used just a 2-ml reactor vessel, but the process appears to be nearly as fast and energy efficient as current, microorganism-based ones. To scale their process up for commercialization, the researchers must find a way to reduce the cost of the enzymes used.

The topography of ink on paper

20 April 2015
At the nanometer scale, paper is jagged and ink takes note of the roughness.

Quantum computing device sees exponential increase in speed

20 April 2015
New Scientist: Another advance has been made in the development of a quantum computer. Fabio Sciarrino of the Sapienza University of Rome and colleagues have been working on a quantum machine that implements an approach known as boson sampling. Their machine is based on a 19th-century counting device called the Galton box, which demonstrates statistical distributions, or bell curves. Invented by Francis Galton, the box consists of a vertical board with rows of pins through which balls are dropped and collect at the bottom in bins. The quantum version uses photons that travel along a network of intersecting channels in an optical chip, collide, and change direction. Sciarrino and coworkers have now increased the speed of their device, previously demonstrated in 2012, by increasing the number of photon sources from one to six. Although the improvement is promising, researchers say there’s still a long way to go before quantum computers surpass classical ones.

Biological clock depends more on light’s color than its brightness

20 April 2015
Science: Biologists have long known that the internal clocks of animals, including humans, adjust according to the available light. What role the different properties of light, such as color and brightness, play in governing a body’s circadian rhythms, however, has not been clear. Tim Brown of the University of Manchester in the UK and colleagues now say that the color of light may be more important than its intensity. They studied an area in the brains of mice called the suprachiasmatic nucleus (SCN). From the electrical signals emitted by the SCN, the researchers were able to watch how the mice reacted to an artificial sky in which the ambient light intensity was varied to mimic night and day, with and without color changes in the light. They found that when natural color changes were removed, the mice’s internal clocks became confused. The researchers suggest that one reason color vision evolved was so animals could continue to reset their internal clocks even when clouds reduced the brightness, but not the color, of light.

Gravity mapping satellite provides clues for geothermal power

17 April 2015

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.

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