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Updated: 2 hours 54 min ago

Green-glowing fungi attract more bugs

20 March 2015
Los Angeles Times: Although bioluminescence has been observed in fungi, it is relatively rare. Among the some 100 000 known fungal species, just 71 have the ability to glow like fireflies. Rather than constantly emitting green light, however, at least one species—Neonothopanus gardneri—appears to be regulated by the circadian clock, according to a recent study published in Current Biology. N. gardneri glows brilliantly at night and shuts off during the day. The reason may have to do with the attraction of insects, which could help spread the fungi’s spores in the dense Brazilian coconut forests where they grow. The researchers tested their theory through the use of prosthetic, acrylic-resin, mushroom-shaped objects artificially illuminated with green LEDs. The fake mushrooms attracted many more beetles, ants, and other insects than did the dark control traps.

Record low reported for Arctic sea ice

20 March 2015
BBC: This year the maximum level of sea ice in the Arctic Ocean, as measured on 25 February, was found to be 130 000 km2 below the previous record low, which was set in 2011. Since satellite records began in the late 1970s, the annual mean Arctic sea-ice thickness has decreased by 65%, according to a recent study. Although the Arctic Ocean will continue to freeze each winter and thaw each summer, regardless of climate change, scientists are observing a fairly clear pattern of substantial sea-ice loss over time. The consequences could prove profound for people, animals, and plants not only in polar regions but also around the world, said Bob Ward of the Grantham Research Institute on Climate Change and the Environment at the London School of Economics.

Physics in West Germany

20 March 2015
In 1966 Physics Today published an overview of physics in the increasingly prosperous country.

Weather radar polarimetry

20 March 2015
Dual-polarization radar promises to improve the modeling of convective storms.

Minibeams may minimize damage in cancer treatment

19 March 2015
Splitting a radiotherapy proton beam into submillimeter pieces can spare normal tissue along the way.

Hybrid drone developed for package deliveries

19 March 2015
MIT Technology Review: A new hybrid gas–electric drone can fly longer and carry heavier payloads than current models. Developed by Top Flight Technologies, the six-rotor unmanned aerial vehicle (UAV) uses batteries to supplement a gasoline-powered engine. The UAV can fly for more than two hours over distances up to 160 km and can carry a payload weighing as much as 9 kg. That is much longer and farther, and with a much heavier payload, than has been achieved by any battery-operated drone on the market. Such a craft is being sought by such internet-based retail and delivery companies as Google, Amazon, and DHL as an efficient and inexpensive way to deliver packages. Top Flight’s hybrid drones may be available for purchase by the end of the year.

Dwarf galaxy gamma-ray signal could come from dark-matter collisions

19 March 2015

Ars Technica: Last week, it was announced that several new dwarf galaxies surrounding the Milky Way had been found. Now, a team led by Alex Geringer-Sameth of Carnegie Mellon University has found that the closest of those galaxies, Reticulum 2, emits gamma rays. The finding is notable because dwarf galaxies generally lack the usual objects, such as black holes and pulsars, that produce gamma rays. And no previous dwarf galaxy has ever been found emitting gamma rays. The signal from Reticulum 2 could be detectable simply because it is the closest dwarf galaxy yet found. Because dwarf galaxies have a high concentration of dark matter, they are believed to be good candidates for study to try to find out what kind of particles dark matter is made of. Geringer-Sameth's team believes that the gamma-ray signal could be evidence of self-interacting dark-matter particles, such as WIMPs, colliding with each other. However, there are still too many characteristics of Reticulum 2 that need to be clarified before that theory can be confirmed.

Royal Society chooses structural biologist Nobel laureate as new president

19 March 2015
Nature: Venkatraman Ramakrishnan has been selected to become the UK Royal Society's new president later this year. He will replace Paul Nurse, a geneticist who has served as president since December 2010. Ramakrishnan is currently the deputy director of the Medical Research Council Laboratory of Molecular Biology. After earning a PhD in physics, he moved into biology and shared the 2009 Nobel Prize in Chemistry for his work on ribosomes, the molecules that construct proteins from DNA. As president of the Royal Society, Ramakrishnan will be serving as the public head of an organization that promotes scientific investment and directly funds research across all fields of study in the UK.

Spacecraft observes aurora above Mars

19 March 2015
BBC: The Mars Atmosphere and Volatile Evolution (MAVEN) spacecraft, launched by NASA in November 2013, has been exploring the Red Planet’s upper atmosphere since it arrived there in September 2014. As reported at the 46th Lunar and Planetary Science Conference being held this week in Texas, last December MAVEN detected the presence of a bright UV auroral glow in Mars’s northern hemisphere, similar to the northern lights that can be observed on Earth. However, the high-energy particles responsible for the phenomenon appear to penetrate much deeper into the atmosphere of Mars than they do on Earth, perhaps because Mars lacks Earth’s protective magnetic field. The aurora sighting, and the detection of dust at altitudes of 150–300 km, may help further MAVEN’s mission of determining how Mars’s atmosphere evolved.

Technology transfer gets new emphasis at DOE

19 March 2015
Under acting director Jetta Wong, the new office will broaden the paths to commercialization.

Harvesting satellite images for commercial use

18 March 2015
MIT Technology Review: Orbital Insight, a startup company founded by James Crawford, uses the vast amount of satellite imagery being collected to provide its clients with business and socioeconomic intelligence. The huge trove of data allows the company to monitor a number of activities, such as how many cars frequent a business’s parking lot each day, how much new construction is going on, and how quickly forests are being depleted. With the use of computer software and a new technique called deep learning, Orbital Insight looks for patterns in the satellite data and makes predictions about a range of industries. Its clients include real estate developers, insurance companies, and environmental nonprofits. The startup is one of a growing number of image-processing companies that are taking advantage of the ubiquitousness of modern satellite surveillance.

Bright spots on Ceres could be ice volcanos

18 March 2015

Nature: Several bright spots have been observed on the asteroid Ceres by NASA's Dawn spacecraft. The asteroid is known to have a significant amount of ice, but the way sunlight is being reflected indicates that the ice does not simply lie exposed on the asteroid's surface. New images from Dawn have revealed that some of the bright spots located in craters are still visible even when the crater walls should block them from the Sun. That observation suggests that, if the reflections are due to ice, the ice must have been pushed up to significant heights. One explanation could be volcano-like eruptions of the ice caused by fluctuating internal pressures within the asteroid. Similar eruptions could also be caused by sunlight warming the asteroid's surface as Ceres rotates from night to day, which could allow icy plumes to form that refreeze and then melt back down to the surface.

Solar gaining momentum in Europe and developing countries

18 March 2015

New York Times: Despite its reputation as a cool, cloudy country, the UK led Europe in the number of new solar installations in 2014. The combination of government subsidies and low prices because of high production rates from factories in China has driven the spread of solar in many European nations. And direct costs have now reached levels where solar can compete with natural gas without the need for subsidies. Thanks to those trends, European solar companies are building solar plants in developing nations such as Chile and India. In northern Chile, high altitude and low latitude allow solar to produce electricity at 80% the cost of coal, and 60% the cost of natural gas. Subsidies have even had some negative influences in the UK and Germany, where they've pushed up the cost of electricity overall. For large solar installations, the UK has begun auctioning guaranteed rates, which it believes will reduce the overall cost of electricity while still spurring solar growth.

Smaller solar-system body may sport Saturn-like rings

18 March 2015
Los Angeles Times: Centaurs, which are a relatively recent classification of a type of solar-system body, are a cross between an asteroid and a comet and orbit the Sun between Jupiter and Neptune. Not much is known about their origins, nor have any ever been photographed up close. In 2011, however, researchers were able to observe one such centaur, named Chiron, as it passed in front of a bright star. Chiron’s shadow indicated that the centaur is surrounded by an “optically thick material,” which astronomers propose could be a system of rings, like those that surround Saturn. Only five other bodies in our solar system are known to have rings, and it wasn’t thought that smaller bodies, like Chiron, would have them. Further observations will be necessary to support the theory.

<em>Washington Post</em> affirms a proposed “Reagan way” on climate

17 March 2015
The newspaper’s opinion editors, generally left-leaning overall, cheer for Republican statesman George Shultz’s op-ed.

Possible explanation for wind-like trails on comet surface

17 March 2015

BBC: When the European Space Agency's Rosetta was approaching comet 67P/Churyumov-Gerasimenko, its pictures of the cometary surface revealed 17 objects that appeared to have trails extending northward away from them. Such trails are common on Earth, where they are formed by wind depositing dust behind boulders or other objects. However, because the comet lacks an atmosphere, there isn't any wind. On Monday at the 46th Lunar and Planetary Science Conference, Stefano Mottola, the project leader of the Rosetta Lander Imaging System, announced that the team believes the trails were caused by splash saltation. The trails would have formed when objects impacted the surface and dislodged particles, which then fell back in the patterns seen.

New technique speeds up 3D printing significantly

17 March 2015

Nature: One of the common methods of 3D printing shines UV light into the bottom of a container of liquid resin, which causes the resin at the very bottom of the basin to solidify. The solid part must then be pulled up to allow new liquid resin to flow in underneath, and the process is repeated. Because of the need to pause after the creation of each layer, the process can take hours to days, depending on the size of the object being printed. Now, Joseph DeSimone of the University of North Carolina at Chapel Hill and his colleagues have developed a new printer that can produce objects in just minutes. They made a reservoir for the liquid resin that has a bottom permeable to oxygen. The oxygen keeps the resin at the bottom from solidifying, resulting in a micron-thick layer of resin that remains liquid beneath the printed object. That allows the object to be printed continuously, with no delays as it is pulled upward. The technique also allows for 3D printing using rubbery materials that did not work in previous machines.

Accelerating Antarctic glacier melt may be driven by deep-ocean processes

17 March 2015
Washington Post: Not only has the great ice sheet of West Antarctica begun to thaw, but one in East Antarctica may now be collapsing as well. The accelerated melting of the two ice sheets could cause global sea levels to rise by as much as 6 meters. To better understand the geography of the Totten Glacier of East Antarctica and the vast catchment of ice it contains, researchers from the US, the UK, France, and Australia compiled data gathered during research flights through the use of gravimetry, radar sounding, and laser altimetry. They discovered that the ice shelves extending out into the water may be becoming increasingly unstable because deep valleys on the seafloor could be collecting vast quantities of saltwater that is warmer and denser than the ice melt above it. To confirm their hypothesis, the researchers would like to launch robotic underwater vehicles that could directly measure the water's temperature, salinity, and other properties.

Ice propulsion system developed for CubeSats

17 March 2015
New Scientist: To help keep CubeSats and other types of nanosatellites in orbit longer, researchers at the Delft University of Technology in the Netherlands have designed a rocket propelled by ice. In space, water ice sublimates directly from a solid to a gas. As it does so, the released vapor molecules could be harnessed to create sufficient propulsion force for the satellite to correct its orbit or control its orientation. The use of ice as a propellant has several advantages over other fuel types: It is both nonexplosive and eco-friendly. A prototype of the researchers’ “micro-resistojet” is being developed for launch in a few years.

William M. Hooke

16 March 2015

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