Physics Today Daily Edition
Science: China’s proposed KuaFu solar wind observatory has been put on hold indefinitely due to loss of funding and support from its international partners. Both the European Space Agency and the Canadian Space Agency had been collaborating with the Chinese Academy of Sciences (CAS) on the mission to put three satellites in orbit to forecast space weather. Although China has successfully launched more than 100 satellites, KuaFu would have been only the second dedicated to science research. Despite attempts to scale the project down to a single satellite, the CAS has also withdrawn its support in light of the fact that KuaFu is no longer a major international collaboration.
MIT Technology Review: The likelihood that a photon will be absorbed as it travels through fiber-optic cables increases with distance, so repeater systems positioned at regular intervals about 100 km apart are needed for maintaining the signals. Such a system works well for conventional communications. However, transmitting quantum information via entangled photons is much more difficult. Quantum repeaters are hard to maintain, especially on undersea cables, because they must be kept at near absolute zero temperatures. Kristine Boone of the University of Calgary in Canada and her colleagues suggest instead using a small network of satellites whose primary functionality would be producing entangled photon pairs. Those photons would then be sent to separate ground stations where they would entangle the quantum data stored in those stations. The entanglement would then be used to securely transmit the data.
Science: Weakly interacting massive particles (WIMPs) are a hypothesized form of dark matter. According to the model that describes WIMPs, large numbers of the dark-matter particles formed in the early universe. When they interacted with each other, they decayed into normal particles. As the universe expanded, such interactions became rarer, leaving enough WIMPs in proportion to ordinary matter to fit astrophysical observations. Because no WIMPs have yet been directly detected, however, alternative theories have been proposed, including the existence of strongly interacting massive particles (SIMPs). In a new paper, Yonit Hochberg of Lawrence Berkeley National Laboratory and her colleagues argue that the production and elimination of SIMPs could have followed a similar pattern as that proposed for WIMPs. And because SIMPs are more likely to interact with regular matter, they should be easier to detect.
BBC: The French government is looking into the origin of several small, unmanned aircraft that were seen flying over 7 of France’s 19 nuclear facilities over the past month. According to French law, no aircraft is allowed to fly below 1000 m within 5 km of a nuclear plant. The first drone was observed on 5 October near the Creys-Malville plant in the southeastern part of the country, and four different drones were observed on 19 October hovering over plants in four different regions of the country. Although Greenpeace was initially suspected, the group has denied responsibility. Because of the aircraft’s small size, it is believed to be unlikely that they could cause any serious damage.
New Scientist: Humans can be acutely sensitive to certain odors, particularly those perceived to be unpleasant. Now a pair of researchers has developed a mathematical model to rate smells on a numerical scale based on their physical and chemical properties. Canceling out a particular smell requires a compound of equal and opposite rating, such that the two combined yield a zero score overall. Thus, rather than try to mask an existing smell with one that is more powerful, they propose creating the olfactory equivalent of white noise. According to their simulations, eliminating the notoriously pungent odor of an onion, for example, would require a blend of 38 different compounds. Next they plan to work on a device that would put the theory to the test.
BBC: The ability to control vocal frequency and to apply other effects determined by cultural influences appears to be the technique used by the most effective speakers. In a new study, UCLA's Rosario Signorello and colleagues modified the vocal frequencies of recorded speeches from several male politicians. They asked 250 volunteers to categorize the speeches by choosing from 67 adjectives, such as attractive, convincing, dishonest, dynamic, fair, and scary. The volunteers were also asked which voices they preferred. The researchers found that the best speakers were able to adjust their voices to convey a range of different characteristics as needed. The ability to reach deeper tones, which can be considered authoritative or sexy, is partially inherent in speakers with larger voice boxes and vocal folds. But much of what determined charisma depended on the audience: French listeners preferred moderate frequencies, which they said sounded prudent and fair, while Italian listeners preferred lower-pitched voices, which they perceived as authoritarian and menacing.
Ars Technica: One reason life developed on Earth may be the planet's abundance of nitrogen, an essential ingredient for the formation of amino and nucleic acids. About four-fifths of Earth’s atmosphere is composed of nitrogen. Until recently, however, exactly where the nitrogen came from was unknown. Now Sami Mikhail and Dimitri Sverjensky of the Carnegie Institution of Washington propose that Earth’s plate tectonics are responsible. Nitrogen is easily incorporated into silicate minerals, not only on Earth but also on other planets, such as Earth’s nearest neighbors, Venus and Mars. Unlike those neighbors, however, Earth is geologically active, and the combination of plate subduction and volcanic eruptions results in the release of copious amounts of volatile chemicals, including nitrogen, into the atmosphere. According to the researchers' findings, nitrogen started accumulating in Earth’s atmosphere some 3 billion years ago, which agrees with other estimates for how long Earth’s plate tectonic system has been active.
Nature: In response to global warming, the Heat Wave Magnitude Index (HWMI) has been devised to provide a way to compare the severity of heat waves around the world and over time. Similar to the Richter scale for comparing the magnitude of earthquakes, the HWMI is designed to be more comprehensive than previous systems by taking into account heat intensity and duration in different regions and in different years. According to the new scale, the worst heat wave to date occurred in Russia during the summer of 2010 when 55 000 people died. The HWMI also predicts that the number and size of heat waves will continue to increase throughout the 21st century, a prediction consistent with earlier research.
Science: The Tuesday evening launch of an unmanned Antares rocket from Wallops Flight Facility in Virginia ended abruptly with an explosion six seconds after liftoff. The rocket, built by Orbital Sciences Corp, was headed to the International Space Station with 748 kg of supplies and 727 kg of scientific experiments. Many of the projects lost were designed by students. One, from the Duchesne Academy of the Sacred Heart—an all-girl college preparatory school in Houston, Texas—was to investigate how well fast-growing plants, such as pea shoots, do in microgravity and when exposed to red and blue wavelengths of light. Despite the sad outcome, school administrators emphasized the importance of the experience gained in participating in the program and creating the experiments.
Nature: On 29 August, the Icelandic volcano Bárðarbunga began erupting in a steady flow of lava that has not stopped. It has produced more lava than any Icelandic eruption since 1947, but the amount of sulfur dioxide it has released is far beyond any predictions. Nearly 35 000 tons of SO2 is being released daily, twice as much as produced by all European industries combined. The high levels have caused breathing problems for nearby residents and have elevated pollution readings all the way into central Europe. The Icelandic Meteorological Office is attempting to track and provide warnings about the gas cloud's movement. However, the volcano's remote location and the onset of winter are making it hard to closely monitor the eruption. The timing of the eruption was good because it began in the middle of FUTUREVOLC, an ongoing study of vulcanism and the movement of magma.
Science: In 2029, a football-field-sized asteroid known as Apophis is going to pass within 35 000 km of Earth. Our planet is not in any danger, but simulations run by Derek Richardson of the University of Maryland, College Park, and his colleagues suggest that Apophis could experience avalanches, albeit very small ones. Pictures of another asteroid believed to be similar to Apophis indicate that instead being solid rock, the two asteroids are clumps of debris loosely held together by gravity. In Richardson's simulation, the tidal force of Earth's gravity caused small, slow-moving avalanches of the lighter pieces of debris on the asteroid's surface. Although astronomers will not be able to see the avalanches directly, IR pictures of the surface could reveal areas that have been uncovered as the surface shifts.
New Scientist: Astronomers continue to be surprised by Saturn’s moon Enceladus. Most of the planets and moons studied so far consist of a core of dense material covered by a large mantle and an outer crust. Based on computer modeling, however, Enceladus’s core can’t be stiff and rocky and also produce the huge watery plumes that have been observed shooting into space as the moon orbits Saturn. In order to generate the heat necessary to melt the icy crust and shoot the jets, the moon’s core may be more like a rubble pile with empty spaces filled with ice or water, similar to a snow cone. The finding has implications for the search for extraterrestrial life because such hydrothermal systems are important to the formation of biological organisms.