1887

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 80 posts for the selected month (August 2015).
August 31, 2015 3:15 PM

Bioengineered heart tissue inspired by Velcro

New Scientist: A new way to grow three-dimensional cardiac tissue has been developed that makes use of a temporary 2D supporting framework, or mesh, with tiny holes and hooks. Called Tissue-Velcro, the material consists of heart cells grown on the mesh in single-cell layers. When the layers are stacked, the hooks snag on the holes, which allows the layers to grow together. The resulting material could then be used as a sort of living bandage to repair the heart’s vessels or valves following a heart attack. The technique could also be used to grow other complex tissues, such as those in the skin or liver. Eventually the polymer mesh breaks down of its own accord.
August 31, 2015 1:26 PM

Final destination chosen for New Horizons

Nature: After passing by Pluto last month, NASA's New Horizons had enough fuel to adjust its course to visit another body in the Kuiper belt, but its second destination had yet to be chosen. On 28 August, NASA announced that the craft would target 2014 MU69, with an expected arrival date of 1 January 2019. The New Horizons team found 2014 MU69 with the Hubble Space Telescope. All that is known about it is that it is a "cold classical" Kuiper belt object (KBO) with a diameter of 45 km. Unlike Pluto, KBOs have relatively circular orbits, undisturbed by the giant planets in the outer solar system. New Horizons will pass within 12 000 km of 2014 MU69, as close as it passed Pluto. Afterward, it will continue to take pictures of other KBOs but at a distance of about 15 million km.

August 31, 2015 1:14 PM

Tesla to purchase lithium compounds from Mexican mine

Ars Technica: On Friday, Tesla announced that it has signed a 5-year deal with Bacanora Minerals Ltd and Rare Earth Minerals Plc to purchase lithium mined in northern Mexico. The deal will require the companies to establish the mine, which has not yet been built, and processing facilities to produce lithium hydroxide and lithium carbonate. When the mine begins operations, it is expected to produce 35 000 tons of the lithium compounds per year. That amount will eventually expand to 50 000 tons. Once the mine has begun operating, Tesla will purchase the produced lithium at below-market rates for use in its Gigafactory, currently under construction in Nevada. Tesla will be able to contribute to the mining companies' fundraising for construction of the mine, which they previously estimated would cost $114 million.

August 31, 2015 11:45 AM

New ice cream ingredient lowers calories, prevents melting

Telegraph: Ice cream recipes may soon include a new ingredient—a protein known as BslA—which keeps it from melting so quickly and prevents the formation of ice crystals. Cait MacPhee of the University of Edinburgh and colleagues say the protein binds with the air, fat, and water in the ice cream to create a smooth consistency. An additional benefit is that ice cream made with the protein could have less saturated fat and fewer calories. The researchers say the protein is easily created with bacterial cultures.
August 28, 2015 4:03 PM

Latest test appears to confirm spooky action at a distance

Nature: Quantum mechanics suggests that entangled particles share the same states and can communicate with each other instantaneously, regardless of the distance that separates them. Albert Einstein rejected that idea, which he labeled "spookiness," and proposed instead that perhaps entangled particles have a predefined set of hidden properties that determine their later behavior. In the 1960s John Bell proposed that hidden variables could explain only a certain level of correlation, and several tests of that proposal have all favored spookiness. Those tests, however, had loopholes, either because too many of the entangled particles weren't detectable or because the particles were too close together to tell if the "communication" between them was faster than light. Now, Ronald Hanson of Delft University of Technology in the Netherlands and his colleagues have performed the first Bell experiment that closes both loopholes. They used entangled photons to entangle electrons that were separated by 1.3 km, far enough apart to detect a time delay. When they measured the electrons, they detected enough of the entangled particles to surpass the threshold that Bell set. And the overall result of the experiment confirmed the standard quantum mechanical view of spooky action at a distance.

August 28, 2015 3:00 PM

New microscopy technique uses structured illumination

MIT Technology Review: Because the macromolecular dynamics of living cells take place so quickly and on such a small scale, tracking them requires very specialized microscopy techniques. Although high-resolution microscopy can capture images of cells by tagging them with fluorescent molecules, the intense light required can damage the cells. Researchers have now found a way to image cells far faster, with much less light, and at higher resolutions by using a new technique called structured illumination microscopy. In their paper published today in Science, the researchers describe in detail the two approaches they used to achieve live-cell imaging at resolutions finer than 100 nm.
August 28, 2015 2:50 PM

NASA says Earth’s sea level has risen 8 cm since 1992

Guardian: NASA researchers have determined that global sea levels have risen an average of nearly 8 cm since observations began in 1992. The findings, based on some 23 years of satellite data, were presented during a media conference on Wednesday. The rise is not uniform across the globe, however, due to ocean currents and other factors. Whereas some areas may actually experience a drop in water level, others may see a rise of nearly 23 cm. And by the end of the century, global sea levels could go up by as much as 3 m. The researchers say that one-third of the rise is due to the expansion of warming ocean water, one-third to ice loss from the Greenland and Antarctic ice sheets, and one-third to melting mountain glaciers.
August 28, 2015 12:25 PM

Theory proposes knots as cause of inflation and the 3D universe

New Scientist: Inflation, the sudden growth spurt the universe experienced shortly after the Big Bang, required a massive amount of energy. But what provided that energy is still unknown. A new theory proposed by Arjun Berera of the University of Edinburgh, UK, and his colleagues suggests that the early universe could have been flooded with gluon-like particles that formed "flux tubes." Those tubes, which Berera likens to the field lines seen in iron filings around a magnet, would have been incredibly densely packed together. Because the tubes behave like string, they could have become knotted, and that tangle may have contained enough energy to drive inflation. As the universe expanded past a certain point, the knots would have unraveled or broken, which slowed its growth. In addition, knots can form in only three dimensions. If, according to some theories, other dimensions do exist, Berera's theory could explain why we can see only three of them.

August 27, 2015 3:20 PM

US program promotes concentrated solar power

MIT Technology Review: Eleven new solar projects are to receive $24 million in funding as part of a new program launched by the US Advanced Research Projects Agency–Energy. Called MOSAIC (microscale optimized solar-cell arrays with integrated concentration), it aims to promote concentrated photovoltaic technologies in order to achieve a higher solar-to-electricity conversion rate. However, because of the materials required, such systems have proven to be very expensive, and they only work in regions with a lot of direct sunlight, such as the American Southwest. The new program seeks to develop more affordable materials and improve the technology to make use of more diffuse sunlight. The goal is to reduce US greenhouse gas emissions and its dependence on foreign sources of energy.
August 27, 2015 2:00 PM

Next-generation synchrotron fires up in Sweden

Nature: A new synchrotron x-ray light source built at Sweden’s MAX IV facility in Lund achieved its first milestone event on 25 August when electron bunches were successfully beamed all the way around the synchrotron’s 528-m-long outer ring. The electrons, whose circular trajectories cause them to emit x rays, are steered and focused by a series of magnets. Compared with earlier models, the new machine achieves stronger magnetic fields with the use of more compact magnets, which are also less expensive and use less electricity. The resulting intense pulses of x rays could be used in any number of laboratory applications, such as studying the chemical reactions inside a battery in real time or the structure of much smaller protein crystals than has been possible with existing light sources.
August 27, 2015 1:00 PM

Emission-reduction effort in London fails to improve air quality

New Scientist: Despite the establishment of a low-emission zone in London in 2008 to try to cut the city’s traffic-related air pollution, no measurable improvement in air quality was achieved during the first three years of the program, according to a study by Frank Kelly of King’s College London and his colleagues. The researchers based their finding on measurements of air particulates and polluting gases, such as nitrogen oxide, and on the respiratory health of schoolchildren. They found neither measurable decreases in NOx or particulate matter nor marked improvement of various pollution-related symptoms, such as wheezing, rhinitis, and eczema, in children at 23 London schools. The researchers say one reason might be an increase in the number of diesel-powered vehicles, which have been promoted as producing fewer greenhouse gases but which may also generate more health-compromising pollutants.
August 27, 2015 11:40 AM

Parents sue school over son’s alleged sensitivity to its Wi-Fi network

Ars Technica: Parents of a young boy have brought a lawsuit against the private boarding school he attends. They claim that their son is suffering from electromagnetic hypersensitivity syndrome due to the industrial-capacity Wi-Fi system the school installed and that the electromagnetic emissions cause him to experience “headaches, nose bleeds, dizziness, chest pains and nausea,” all of which disappear once he is home. The parents allege that when they brought their concerns to school officials and asked that the school “make reasonable accommodations” for their son’s “disability” by reducing the emissions to a physically tolerable level, the school refused, adopted a hostile attitude, and threatened to dismiss the student. Although a number of people say they suffer from electromagnetic hypersensitivity, no scientific evidence or study backs up that claim.
August 26, 2015 4:40 PM

Quantum dots could turn windows into solar panels

Ars Technica: Although solar panels can generate a large amount of carbon-free electricity, installing them in existing buildings is expensive. Incorporating them into windows and other parts of buildings would make solar energy much more affordable. However, photovoltaic cells not only block the view but also absorb a certain amount of the incoming light and cause the light that does enter the building to be tinted. A new alternative uses a transparent polymer that can be embedded in the window or applied as a coating. The polymer includes a diffuse cloud of quantum dots made of copper, indium, and selenium. The dots absorb light across the spectrum and reemit it at a specific IR wavelength, which the polymer then guides to the edge of the window glass. From there, the light is fed into a silicon photovoltaic device, which very efficiently absorbs it. Filtering out only 20% of the incoming sunlight, the device can convert just over 3% of it to electricity. Although the new material cannot harvest as much sunlight as regular solar panels, the giant walls of glass on a skyscraper could still produce a fair amount of electricity for relatively low cost.
August 26, 2015 3:10 PM

Articles with shorter titles receive more citations, says study

Nature: Journals that "publish papers with shorter titles receive more citations per paper," according to a study published in Royal Society Open Science. Adrian Letchford of the University of Warwick in Coventry, UK, and his colleagues mined the Scopus database and analyzed 140 000 papers listed there that were published between 2007 and 2013. They reached their conclusion by comparing title lengths and numbers of citations. However intriguing their finding, the researchers say, it is not necessarily definitive because of the number of other factors that could be involved, including the fact that different journals place different restrictions on the number of characters allowed in a title and the fact that subject matter and author seniority can also affect a paper’s citation rate. Regardless, clear, tightly constructed titles are always in the authors' best interests, says Karl Ziemelis, Nature’s chief physical sciences editor.
August 26, 2015 3:00 PM

Supposed dragon pictograph refuted by x-ray technology

Science: Since the late 1920s, when a rock painting was discovered in Utah’s Black Dragon Canyon, people have been debating what exactly is depicted in the faded and ancient pictograph. Over the years it has variously been described as a winged monster, a dragon, or a pterodactyl. Rock art researchers and archaeologists, however, have said that rather than showing a single figure, the drawing depicts five figures—two humans and three animals. Such a tableau, they say, is common in the Barrier Canyon style of art seen in that region. To try to finally lay the controversy to rest, researchers used x-ray fluorescence to measure the iron content of the red ochre pigment used in the drawing and a software program called DStretch, which can boost and sharpen digital images. The two methods revealed “pretty clearly” that there are five figures, says Marvin Rowe, a retired professor emeritus at Texas A&M University in College Station and a coauthor of the study.
August 26, 2015 11:40 AM

Stephen Hawking proposes that information may not be lost in black holes

Wall Street Journal: One of the apparent consequences of Stephen Hawking's theory that black holes leak radiation is that over time they would evaporate and disappear. The information about all the particles they absorbed would then be lost. That concept, however, contradicts a tenet of quantum mechanics that information cannot be lost or destroyed. On Tuesday, at a conference at the Royal Institute of Technology in Stockholm, Sweden, Hawking presented a new theory about how that information might be preserved: Instead of being stored in the interior of a black hole, the information may be stored in its boundary, the event horizon, and then carried away by the emitted radiation.

August 25, 2015 2:35 PM

Saturn’s F ring may have formed from collision of two moons

Japan Times: Encircling Saturn’s main ring system is a narrow band of icy particles called the F ring. But until now, how the ring originated and why it appears to have two tiny “shepherd” moons—Prometheus and Pandora—was not known. Ryuki Hyodo and Keiji Ohtsuki of Japan's Kobe University have used computer simulations to show that the ring may have resulted from the collision of two small satellites near the outer edge of Saturn’s main ring. However, the satellites probably did not collide head on, but rather at an angle. According to the researchers, “Such an impact results in only partial disruption,” not total destruction, of the moons. The narrow ring of particles produced would then go on to form a new ring. Not only may that theory explain Saturn’s F ring, but it could also explain certain features in the Uranian system, says CNRS's Aurelien Crida, who commented on the study in Nature Geoscience.
August 25, 2015 2:20 PM

D-Wave quantum computer appears to run faster than classical model

New Scientist: Canada’s D-Wave Systems, which sells what purport to be the world’s first quantum computers, says its latest model is 15 times faster than a regular PC. However, that claim has been disputed by various experts. One issue is the nature of the test. The D-Wave computer was tasked with solving a random optimization problem, which it was able to do in 20 microseconds. The regular computers took longer to find a solution “of equivalent quality.” But although the D-Wave computer found more solutions faster than the regular computers, it may not necessarily be faster at coming up with the best solution. Another issue is that classical computers use multiple cores to split up the computations and speed up the processing time. But the test PC used just a single core. Perhaps the best way to prove D-Wave’s computers are truly quantum is to have them show progressively faster performance on ever-larger problems, which hasn't happened yet.
August 25, 2015 2:15 PM

Loophole exploited in carbon-credit facilities

Nature: Although carbon credits were created as part of the Kyoto Protocol to encourage nations to invest in emissions-reduction projects, they can become so valuable that in some cases they have presented a perverse incentive. For certain waste gases, revenues from carbon credits can exceed the abatement costs and even the costs of producing the main product, according to a recent study published in Nature Climate Change. Such was the case for at least two Russian chemical plants, which since 2008, when the credit scheme began, were found to have increased their production of two potent greenhouse gases—trifluoromethane and sulfur hexafluoride—with no corresponding increase in their production of chlorodifluoromethane, a chemical used as a refrigerant. They then collected the financial benefits from destroying the greenhouse gases that they had produced. Such abuses exist, say the study authors, because of the lack of oversight by participating governments. The program may be improved or even abandoned altogether as new climate targets are set at the upcoming United Nations climate change conference to be held in Paris later this year.
August 25, 2015 1:46 PM

Middle Eastern conflicts have lowered air pollution

Los Angeles Times: Satellite images of the Middle East over the past 10 years have revealed a drop in the levels of nitrogen oxide, sulfur dioxide, and other air pollutants. The drop does not appear to be the result of any clean-air laws or other changes but does coincide with the spreading conflicts there. Jos Lelieveld of the Max Planck Institute for Chemistry in Mainz, Germany, and his colleagues found the trend in data collected by the Ozone Monitoring Instrument on NASA's Aura spacecraft. They were studying the impact of air-quality standards adopted by countries in the region. Since 2011, when the Arab Spring protests reached Syria and escalated into civil war, the concentration of NO has dropped by 40% over Damascus and by 50% over Aleppo. Similar drops in emissions were noted in Iraq and Egypt. However, emissions rose in Beirut and other parts of Lebanon, probably because of the flood of refugees to those countries.

See more
/content/aip/magazine/physicstoday/news/news-picks
201508
This is a required field
Please enter a valid email address

Oops! This section does not exist...

Use the links on this page to find existing content.

24f368529419bb89b4d14b71017867b2 weblog.blogzxybnytfddd
Scitation: News Picks - Blog
http://aip.metastore.ingenta.com/content/aip/magazine/physicstoday/news/news-picks