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Updated: 3 hours 46 min ago

Astronomer crowdfunds telescope to solve 40-year-old radio wave mystery

15 April 2016
Guardian: On 15 August 1977, a powerful blast of radio waves lasting 72 seconds was detected coming from a group of stars called Chi Sagittarii by astronomer Jerry Ehman of the Ohio State University. Long thought to indicate the existence of an extraterrestrial intelligence, the so-called Wow! signal has not been observed since. Now Antonio Paris of St. Petersburg College in Florida may have a more mundane explanation. Paris found that two comets—266P/Christensen and 335P/Gibbs—were both near Chi Sagittarii the day the Wow! signal was detected. Comets are surrounded by clouds of hydrogen gas and can emit radio frequencies similar to those detected by Ehman. To test his hypothesis, Paris hopes to observe the next passage of the two comets past Chi Sagittarii in 2017 and 2018 and has launched a crowdfunding campaign to raise the $13 000 needed to buy a radio telescope to do so.

DARPA funds computer chip that introduces small errors in its calculations

15 April 2016

MIT Technology Review: The Defense Advanced Research Projects Agency wanted to find a way to improve results from computer software when the input data is noisy. To do that DARPA worked with Joseph Bates of Singular Computing to develop a computer chip designed to produce close-but-incorrect answers to mathematical calculations: When asked to add 1 and 1, it came up with answers like 2.01 or 1.98. Bates tested the chip for a variety of functions and found that it performed very well on tasks such as high-resolution radar imaging, extracting 3D information from stereo photos, and deep learning. In a test of software that tracks objects in a video, the chip was 100 times as fast as a conventional chip and used less than 2% as much power.

Coverage of Nuclear Security Summit presents confusing message

14 April 2016
The recent summit centered on securing nuclear materials and preventing nuclear terrorism. But the message to the public focused on fear.

Foam mitigates key obstacle in quest for laser fusion

14 April 2016
A thin layer of wispy foam reduces the impact of Rayleigh–Taylor instabilities and thus enables more even implosions.

Largest US coal company files for bankruptcy

14 April 2016
NPR: On 13 April, Peabody Energy—the largest coal-mining company in the US—filed for chapter 11 bankruptcy protection. Peabody follows in the footsteps of the second-largest company, Arch Coal, which filed for bankruptcy earlier this year, and three other major coal companies that went bankrupt the year before. Peabody cited a slump in the coal industry as the reason for its difficulties. One of the world’s largest markets for coal, China, has been experiencing an economic downturn over the past several years. In addition, coal faces increasing competition in the US as shale-gas production and solar and wind projects ramp up. Peabody’s filing should allow the company to restructure its debt load and effect other changes in order to continue operating.

Synthetic neural bypass returns muscle control to paralyzed hands

14 April 2016

IEEE Spectrum: Ian Burkhart broke his neck in 2010, which resulted in his becoming paralyzed from the fifth cervical vertebrae down. That meant he was only able to move his head, neck, and upper arms. Now, Chad Bouton of the Feinstein Institute for Medical Research in New York City and his colleagues have developed a neural implant that connects to an electronic sleeve on Burkhart's forearm and restores his control over one of his hands. The implant is an array of 96 electrodes that monitors electrical activity in the brain's motor cortex at a rate of 30 000 times per second. Burkhart had to train multiple times per week for 15 weeks so that the system could learn which signals corresponded with certain intended motions. Once the neuro-electrical signals were mapped to movements, the implant sent electrical pulses to the sleeve on Burkhart's forearm. The sleeve contained 130 noninvasive electrodes that stimulated the muscles necessary to move the fingers, hand, and wrist. When outfitted with the system, Burkhart was able to perform actions such as swiping a credit card and using the game controller to play Guitar Hero. Currently the system requires running a cable from the implant to the sleeve, but the researchers hope to be able to create a wireless communication system.

Computer game tests human understanding of quantum physics

14 April 2016
Nature: Creating video games to fold proteins, map quantum circuits, and solve other puzzles in science is becoming a popular area of research. Now Jacob Sherson of Aarhus University, Denmark, and his colleagues have created a game called Quantum Moves that addresses a key question in quantum computing: How quickly can a laser move an atom between containment wells without altering the atom's quantum state? Players are tasked with moving a sloshing liquid between two wells by moving the wells toward each other. The catch is that the liquid doesn't behave like a liquid; instead, the liquid is controlled by the laws of quantum mechanics, which allow it to do such things as tunnel between the wells. Sherson's team can then compare the movements of the player-controlled wells to real-world attempts at moving atoms between containment wells. After analyzing the gameplay of about 300 people, the researchers found that more than half of the human solutions beat the computer algorithms that are normally used for solving the problem.

Starshot spacecraft could explore solar system first

14 April 2016
Space.com: On 12 April theoretical physicist Stephen Hawking and Russian entrepreneur Yuri Milner announced Breakthrough Starshot, a $100 million initiative to develop an ultralight spacecraft that could travel one-fifth the speed of light. Although the ultimate goal is to travel beyond our solar system to look for signs of life, the first trips will probably be to destinations much closer to home. Members of the Starshot scientific advisory team cited targets such as Saturn’s moon Enceladus and Jupiter’s moon Europa, both of which have liquid oceans beneath their icy surfaces.

Yuri Milner and Stephen Hawking reveal program to develop interstellar probes

14 April 2016

The Atlantic: On Wednesday Russian billionaire Yuri Milner, joined by Stephen Hawking, announced the newest of Milner's Breakthrough Initiatives: Starshot, a $100 million research program to build spacecraft capable of traveling to Alpha Centauri in 20 years. For comparison's sake, the current fastest-moving spacecraft is NASA's New Horizons, which would take tens of thousands of years to reach Alpha Centauri. And at just 4.4 light-years away, Alpha Centauri is the star system closest to Earth. The program involves deploying an array of lightweight disks fitted with photon thrusters for navigation, a power source, cameras, and a communication system. Propulsion would come from a ground-based laser shining onto one side of the disk, providing pulses of energy to accelerate each probe away from Earth. Milner thinks the technology for interstellar travel can be developed within his lifetime.

Three baseball myths debunked by physics

13 April 2016
In the inaugural post of his Extra Dimensions blog, online editor Andrew Grant explores the physics underlying America’s pastime.

Threat from wildfires is now nearly year-round

13 April 2016

New York Times: Wildfires used to occur primarily during a single season of the year, but the drier winters and warmer springs of a changing climate have created conditions that are making wildfires a year-round hazard. The expansion of residential populations and inconsistent policies regarding fire prevention and combat have exacerbated the problem. Last year, a record 10.1 million acres burned in the US; the top five years for acres burned have all occurred in the past decade. The cost of fighting wildfires is growing too: Annual costs have reached $2 billion in the US. In February, Hawaii exhausted its federal funds for fighting fires four months before peak fire season began. Alaska's first fires began in February, a month when the state is usually covered in snow.

Japanese probe to Venus returns first data

13 April 2016

Nature: The Japan Aerospace Exploration Agency (JAXA) launched Akatsuki ("Dawn") in 2010 on a mission to Venus to study the planet's atmosphere and to look for signs of active geological processes. But a faulty engine valve caused the craft to sail by Venus and orbit the Sun. In December JAXA saved the mission by using the probe's secondary thrusters to finally achieve a Venus orbit. Now the team managing the spacecraft has presented the first images collected by Akatsuki's cameras. Taken 100 000 km from the planet, the images show details of the clouds in Venus's sulfurous atmosphere.

Century-old astronomical spectrum reveals oldest evidence of exoplanet

13 April 2016

Gizmodo: In 2015 Jay Farihi of University College London requested a 1917 glass plate from the Carnegie Observatory for an article about planetary systems around white dwarfs. The plate contains an image of the spectrum of the white dwarf known as van Maanen's star. Photographic glass plates were used in the late 19th and early 20th centuries to study the chemical composition of stars. Farihi spotted an absorption line in the spectrum, indicating that something with a variety of heavy elements such as calcium, magnesium, and iron had blocked the star's light. White dwarfs having that sort of absorption pattern probably host rocky planetary systems. Farihi's find predates the next earliest known evidence of a probable exoplanet by more than 70 years.

Whether gem grade or industrial grade, most diamonds formed under similar conditions

12 April 2016
Science News: Some diamonds are more prized than others. Gem-quality diamonds, which tend to be billions of years old, are notable for their brilliance and lack of impurities. So-called fibrous diamonds are just millions of years old and tend to be cloudy and full of impurities. Because the two types of diamond look so different and are of such different ages, it was long thought that they must have formed under different geological conditions. However, even the most perfect diamonds contain imperfections, and those imperfections are now providing clues to the diamonds' origins. Using a beam of electrons, researchers were able to identify tiny inclusions in diamond gemstones, which contained the same carbonate-bearing fluids found in the more fibrous diamonds. The team concluded that all diamonds must form from carbon carried deep into Earth's interior, where it is exposed to extremely high pressures and temperatures. Furthermore, based on the age of some gemstones, the plate tectonics that carry the carbon into the planet’s interior must have started operating even earlier than previously thought, perhaps as long as 3.5 billion years ago.

SpaceX will try to reuse rocket that achieved sea landing

12 April 2016
Los Angeles Times: On 8 April SpaceX’s Falcon 9 reusable rocket reached another milestone: After successfully launching the Dragon spacecraft on a resupply mission to the International Space Station, the first-stage rocket successfully landed on a barge floating in the Atlantic Ocean. Whereas previous flights have landed on solid ground, this is the first time the company achieved a sea landing. The rocket will now be shipped to Port Canaveral, Florida, where it will undergo a series of tests to make sure it was not damaged by the shaking and stress that occured during the journey. If the rocket passes all tests, it could be relaunched as early as June. To be commercially viable, however, future rockets will need to be ready for reuse within weeks rather than months, says SpaceX CEO Elon Musk. He expects each rocket will be capable of completing some 10 to 20 missions—and possibly as many as 100 missions—with some minor refurbishments.

NASA loses and regains contact with <em>Kepler</em> telescope

12 April 2016

Guardian: Last week, NASA's Kepler space telescope unexpectedly went into emergency mode, during which contact with the satellite became intermittent. Launched in 2009 and now situated roughly 120 million km from Earth, Kepler had a successful initial mission in which it detected nearly 5000 extrasolar planets by 2012. The following year, two of Kepler's four reaction wheels, which are used to stabilize the telescope, failed. NASA was able to repurpose the telescope for a mission dubbed K2. The unexpected loss of contact with Kepler occurred when the NASA team attempted to send commands to reorient the telescope just days before the start of a new survey. NASA was able to regain full communications with Kepler over the weekend and is now investigating what caused the emergency shutdown.

New measurement doesn't resolve disagreement over Hubble constant

12 April 2016

Scientific American: Two methods have been developed to determine the rate of the universe's expansion, called the Hubble constant. But they don't yield the same result. Researchers measuring the cosmic microwave background (CMB) radiation came up with a value of 67.3 ± 0.7 km/s/Mpc. Another group of researchers, who used the distance ladder method, now report a value of 73.02 ± 1.79 km/s/Mpc. The new study uses known cosmic distance markers, such as Cepheid variable stars and Type 1a supernovae, to calibrate measurements of galaxies' distances and redshift, or how quickly the galaxies are moving. That technique was used by Adam Riess of the Space Telescope Science Institute in Baltimore, Maryland, and his colleagues in the 1990s to prove that the universe's expansion was accelerating. Riess's team is also behind the latest study, which includes several new calibration points that yield a more precise value. Both the CMB and distance ladder research teams are continuing to examine their data and calculations to try to understand why the two systems still don't agree.

William Hill Reid

12 April 2016

How bats optimize foraging

11 April 2016
Bats adopt flight paths that enable them to eat airborne insects in quick succession.

Clouds may not slow global warming as much as thought

11 April 2016
New York Times: Clouds can consist of tiny liquid water droplets, tiny ice crystals, or both. In a recent study, researchers concentrated on mixed-phase clouds and their effect on global warming. The scientists found that such clouds have more water and less ice than expected, and that the water–ice ratio will continue to grow as the atmosphere warms. Although water droplets reflect more solar radiation back into the sky than ice crystals do, the fact that there is less ice to begin with may reduce the clouds’ cooling effect. The researchers caution that there is still a high level of uncertainty in exactly how much loss there will be in such clouds’ cooling power, but the findings mean it will almost certainly be harder to keep global warming to the 2 °C limit set by the Intergovernmental Panel on Climate Change.

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