Physics Today’s online staff summarize the most important and interesting news about science from the world's top media outlets.
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.
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.
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.
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.
Nature: Carbon nanotubes wrapped in polymers can be used to test for the presence of a range of molecules in blood. The polymers are designed to attach to specific molecules. The nanotubes fluoresce naturally, but their brightness changes when they are attached to the target substance. This makes it easy to detect the presence of the substance as well as its concentration. Michael Strano of MIT and his colleagues have successfully tested the devices as both injections and subdermal implants in mice. The injectable devices can be used for detecting large molecules such as fibrinogen, which is involved in blood clotting, a process that is not easy to monitor with existing technologies. An implant for detecting nitric oxide, which was embedded in a hydrogel matrix, was functional in mice for more than a year with no local inflammation.
Science: The storage capacity of a supercapacitor is limited by the surface area of the electrodes and by the electrodes' ability to absorb and release electrons. Research on redox-active materials focuses on the latter problem, but the materials are fragile and not particularly porous so have a low surface area. Two years ago, William Dichtel of Cornell University and his colleagues created a highly porous crystal, called a covalent organic framework (COF), that is also redox-active, but it did not have the conductivity necessary to be commercializable. Now they have revealed that coating their COF with a conductive polymer increased the capacitance from 160 F/g to 350 F/g, higher than any commercial supercapacitor. Because the materials used in Dichtel's device are readily available, they have much more promise for commercial use than harder-to-create carbon-nanotube capacitors.