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Updated: 2 weeks 4 days ago

Polarization of light used to make Möbius strips

2 February 2015

New Scientist: If you take a strip of paper and give it a half twist and tape the ends together, the result is the one-sided loop known as a Möbius strip. Now, Peter Banzer of the Max Planck Institute for the Science of Light in Erlangen, Germany, and his colleagues have demonstrated a similar effect using light. In 2005 it was predicted that light's polarization could become twisted like a Möbius strip. Banzer and his team achieved the effect by scattering two polarized beams off gold nanoparticles in such a way that the beams interfered with each other. The resulting light had polarizations with either three or five twists. The ability to twist polarized light could reveal details about light's 3D structure, which could lead to uses in biomedical imaging and particle manipulation.

Yucca Mountain proposal deemed safe but is not recommended

2 February 2015

Nature: On 29 January, the Nuclear Regulatory Commission (NRC) released the final two volumes of its technical analysis of the Department of Energy's proposal to use Yucca Mountain in Nevada as a nuclear waste repository. Although the report indicates that DOE's plan is sound, the NRC does not recommend going ahead with the construction. President Obama abandoned the project five years ago. Yet a federal court ruled that the NRC had to continue the study while it still had funds to do so. Even if Congress were to provide more funding for the next step (a further analysis of ecological impacts), the local governments in Nevada are openly resistant to selling the land to the federal government. Without that land, construction cannot begin.

Poll finds growing Republican support for action on climate change

2 February 2015
New York Times: According to a recent telephone poll, a growing number of Americans believe that climate change is occurring and is caused by human activity. In addition, a majority of Americans support government action to fight global warming, and two-thirds prefer political candidates who say they will take on that challenge. The poll was conducted by the New York Times, Stanford University, and Resources for the Future, a nonpartisan environmental research group. Although by party, Democrats are much more likely than Republicans to feel that global warming is an important issue, the poll found that 61% of Republicans admit that reducing emissions is essential to curbing global warming and 51% say the government needs to take action. Many Republican politicians, however, continue to resist efforts to curb global warming on the basis that they will hurt the economy.

Cold plasma shown to fight norovirus

2 February 2015
BBC: Human norovirus is the most common cause of acute gastroenteritis, which is characterized by severe nausea, diarrhea, and vomiting. The virus spreads particularly well in crowded areas, such as cruise ships, and has been difficult to study because it is almost impossible to grow in a laboratory. Now Birte Ahlfeld and Günter Klein of the University of Veterinary Medicine in Hannover, Germany, and their colleagues propose fighting the virus using nonthermal atmospheric pressure plasma, or cold plasma. The room-temperature, ionized gas molecules, created by applying an electric field to ambient air, were shown to be successful at inactivating the virus. Cold plasmas also are being developed for other medical applications, including the treatment of dental caries.

ESA must wait for comet probe Philae to wake up

30 January 2015
BBC: Launched more than 10 years ago, the European Space Agency’s Rosetta spacecraft reached comet 67P/Churyumov–Gerasimenko last August. On 12 November, Rosetta’s robotic lander Philae touched down on the comet’s surface after having bounced twice. Thanks to its primary battery, it was able to transmit about 60 hours’ worth of data before it exhausted its power supply. However, Philae’s exact location has not yet been determined, and it has not received enough sunlight to recharge its secondary battery. ESA controllers hope that as the comet moves closer to the Sun over the next few months, Philae will be able to reboot itself and resume its communications with Rosetta.

Credit card transactions are enough to identify card holders

30 January 2015
Nature: Metadata collected from credit card transactions has provided much useful information to researchers, businesses, and others interested in consumer spending, economic trends, and so forth. To protect the card holders’ identities, their name, address, credit card number, and other information directly linked to them are deleted. However, according to a study published in Science, even without that information, card holders can still be identified. The researchers looked at three months of credit card records for some 1 million people and were able to identify 90% of them just by knowing the date and location of four of their transactions. Although complete anonymity may be impossible in this modern age, progress is being made in creating legislation to protect consumers.

From regional nuclear war to global food crisis

30 January 2015
A nuclear war between India and Pakistan could reduce grain production enough to cause widespread famine.

Journalists debunk vaccine science denial

30 January 2015
Both before and after the Disneyland measles outbreak, most reporters have forthrightly exposed “anti-vaxxers.”

Monitoring global ice loss with hydroacoustics

29 January 2015
BBC: Different types of icebergs make different sounds as they break away from glaciers, according to a study published in Geophysical Research Letters. Oskar Glowacki of the Polish Academy of Sciences and colleagues placed underwater microphones in the ocean and listened to the rumbles, groans, and snaps emitted as ice calved off the Hans Glacier in Svalbard. Combining the acoustic data with time-lapse photography, the researchers discovered three distinct underwater acoustic signatures from the glacier. The data allowed them to distinguish among the various stages of the calving process and determine when they were occurring. To date, glaciers have been monitored primarily with satellites, which can track only large pieces of ice. Hydroacoustics could allow researchers to track smaller ice blocks and better monitor global ice loss as Earth’s temperature rises.

Climate models don’t overestimate global warming, says study

29 January 2015
Los Angeles Times: Even though Earth has appeared to be experiencing a global warming hiatus over the past 15 years, climate models are accurate in their predictions of rising global temperatures, according to a new study published in Nature. Piers Forster of the University of Leeds in the UK and colleagues looked at climate models that cover 1900–2012 and focused on 114 possible 15- and 62-year intervals. Although they found no inherent bias in the models, they did notice that the shorter time intervals were more susceptible to errors caused by manmade activity and by unpredictable periodic climate variations often caused by ocean fluctuations or volcanic activity. The simulations for longer periods tended to more closely match observations. Furthermore, 9 of the 10 warmest years on record have occurred since 2002.

New House science spending chair is a fiscal conservative but a science supporter

29 January 2015

Science: John Culberson (R-TX) is the new chair of the Commerce, Justice, Science (CJS), and Related Agencies spending panel in the US House of Representatives. CJS oversees a large portion of US science research spending, including the funding for NASA, NIST, NSF, and the National Oceanic and Atmospheric Administration. Culberson says that he has had a lifelong passion for science despite his chosen career in law. He also says his desire to support government investment in science does not contravene his fiscal conservatism. However, that support seems to be limited to space science and basic research and does not include the social and behavioral sciences. He says he supports fellow Texas representative Lamar Smith's efforts to focus NSF's research grants on basic science.

Ancient meteorite provides hints about Earth's nitrogen

29 January 2015

Ars Technica: Nitrogen composes about 78% of Earth's atmosphere and is the most common pure element on the planet. However, the nitrogen on Earth does not occur in the same isotope fractions as the nitrogen found in the Sun or in the tails of comets. A new analysis of an ancient meteorite may provide some clues as to where Earth's nitrogen came from. Transmission electron microscopy and secondary ion mass spectrometry reveal that the meteorite contains the mineral carlsbergite. The mineral's characteristics suggest it was formed in the presence of ammonia (NH4), which likely came from ice in the Sun's protoplanetary disk. That ice could later have been part of the material that accreted to form Earth. It is possible that the different isotope ratios of nitrogen found in the Sun and in comets blended in such a way as to produce the nitrogen mix now present on Earth.

Giant impacts may explain the origin of chondrules

29 January 2015
Long thought to be the building blocks of planets, chondrules may instead be a byproduct of planetary accretion.

Nanostructured membrane boosts performance of lithium-air battery

28 January 2015

MIT Technology Review: Lithium-air batteries have a theoretical energy density 10 times that of current lithium-ion batteries. In a car, they would provide energy comparable to that of a full tank of gas. However, current models are still far from reaching that energy density, and the number of times they can be recharged is limited. Lithium-air batteries work by allowing lithium ions to react with the oxygen in air to create lithium oxide. Recharging them involves breaking back down that molecule. The batteries' ability to be recharged is limited because the lithium oxide tends to bond to one of the battery's electrodes, covering the catalyst that facilitates the breakdown of the lithium oxide. A team of researchers from Yale and MIT has developed a new membrane made of catalyst-coated nanofibers to which the lithium oxide doesn't bond. The extra catalyst increases the battery's energy density and doubles the number of recharge cycles. However, the experimental battery can be recharged only about 60 times before it needs to be replaced. Commercial car batteries should be able to be recharged roughly 1000 times. The battery also uses pure oxygen instead of air because air's carbon dioxide reduces the battery's efficiency.

Oldest planetary system discovered so far formed 11.2 billion years ago

28 January 2015
Los Angeles Times: Based on data collected by NASA’s Kepler spacecraft, astronomers have identified an ancient star, called Kepler-444, that has five planets in orbit around it. Smaller than Earth, the planets are thought to be rocky terrestrials rather than gas giants. The system is located some 117 light-years from Earth and formed about 11.2 billion years ago, when the universe was just 2.6 billion years old. The low metal content of Kepler-444 indicates its extreme age because metals have formed and increased in abundance since the Big Bang. By studying the frequency at which the star pulsates, astronomers were able to determine its mass, radius, and density. They detected the planets indirectly, by noting the periodic dimming of the star when the planets passed in front of it. The discovery indicates that Earth-sized planets could have formed throughout most of the universe’s history and that life could have developed very early on.

Soil-mapping satellite scheduled for launch

28 January 2015

Nature: Scheduled for launch on 29 January, NASA's Soil Moisture Active Passive satellite will use microwave signals to measure soil-moisture levels everywhere on Earth and to determine whether the soil is frozen. Clear measurements of soil moisture will help improve water availability models, which are important for both urban and rural areas. The data will help insurance companies to improve crop price models and allow scientists to better monitor droughts and other climate trends. The information on frozen and thawed soil can be used by the military for planning troop movements and by scientists for measuring polar melt due to climate change.

Charles Townes

28 January 2015

Smart scanner developed to detect potholes

28 January 2015
BBC: Potholes, the bane of drivers, form as the asphalt used on roadways degrades. Large potholes can damage vehicles and disrupt traffic flow. Now researchers have found a way to look for potential pothole sites before the potholes form. They have mounted 2D and 3D scanners on the front of a van, which drives around and captures images of road surfaces. A computer algorithm is used to distinguish among different surface textures, including tire marks, oil spills, and previous pothole repairs. It is looking for the loss of fine and coarse aggregate particles from the asphalt mix, which is the hallmark of pavement degradation, called raveling. In a test, the system took just 0.65 second to process the data and identify 900 potential sites.

Treating stroke victims with iron-infused drugs

28 January 2015
A startup seeks to boost the efficacy of clot-busting drugs by adding a co-deliverer: iron nanoparticles.

Floyd Dunn

27 January 2015

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