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Updated: 7 hours 36 min ago

Peer-reviewed study debunks "chemtrail" conspiracy theory

17 August 2016

New York Times: A long-standing conspiracy theory suggests that the condensation trails that form behind planes as they fly at high altitudes are actually "chemtrails" produced by aircraft spraying chemicals into the sky for sinister reasons. Steven J. Davis of the University of California, Irvine, and his colleagues have now published the first peer-reviewed study that examines and debunks a wide range of claims made by supporters of the chemtrail theory. The study surveyed 77 atmospheric scientists, who were asked to provide scientific explanations for such phenomena as the occasional gap in a contrail or elevated chemical levels in the atmosphere. Davis said the goal of the study is to counter the misinformation that appears to be rife on the internet.

US sets new fuel-efficiency standards for trucks

17 August 2016
Washington Post: Continuing his efforts to curb vehicle pollution, President Obama announced on 16 August new fuel-economy standards for trucks and other heavy-duty vehicles. Although such vehicles make up only about 5% of total traffic, they account for 20% of the fuel consumption and carbon emissions. By 2027 the new standards are expected to cut more than 1 billion tons of carbon pollution, save almost $170 billion in fuel costs, and reduce oil consumption by about 84 billion gallons. Unlike previous efforts, the new regulations have received widespread support not only from environmental and consumer groups but also from the trucking industry and companies that rely on it.

Lightning hot spot may provide clues for predicting strikes

17 August 2016
Nature: Lightning can and does strike the same place more than once. In fact, Lake Maracaibo in northern Venezuela sees some 200 strikes/km2 every year. Now Ángel Muñoz of Princeton University and his colleagues plan to spend the next three years there, monitoring the atmospheric conditions and watching for lightning strikes. The goal is to develop an accurate model to predict lightning frequency months in advance, so that scientists will be able to provide warnings for local communities, industries such as oil and gas, and power grid operators. The researchers say, however, that expanding their lightning model to other parts of the world may be difficult because of the lack of long-term lightning observations and the complex effects of season, region, and climate. At least one other study has suggested that lightning frequency may increase with global warming.

NASA scientist detained in Turkey following failed coup

16 August 2016
The Turkish-born physicist is likely the only US citizen who has been arrested in the recent crackdown.

UK government vows to continue EU research funding

16 August 2016
Science: Ever since the UK voted to leave the European Union (EU), UK scientists have worried about the impact of the decision on research funding. In a show of support for its scientific community, the UK government has issued a statement saying it will guarantee the funding for any EU grants awarded to its scientists. The decision was made to bolster confidence among not only researchers in the UK but also their collaborators in other countries. However, critics point out that there is no guarantee the money will continue once the EU funding runs out.

China launches satellite for quantum communications test

16 August 2016

Spaceflight101: On 15 August China launched the Quantum Science Satellite into orbit aboard a Long March 2D rocket. The satellite carries a crystal that generates entangled pairs of photons. An optical communication system splits each pair and transmits one of the photons to a ground station in either Vienna, Austria, or Beijing, China. The photons are then used to generate encryption keys. Researchers have tested similar setups on Earth's surface by using two stations spaced a few hundred kilometers apart. The Quantum Science Satellite will be the first space-based communications test system.

Space-based gravitational-wave lab could get new life

16 August 2016
An intermediate review of NASA’s astrophysics program also calls for reassessment of WFIRST mission costs.

July sets several heat records

16 August 2016
Climate Central: Based on records that go back to 1880, this past July was the hottest July and also the hottest month on record globally, according to NASA. And there’s a good chance 2016 will be the hottest year to date, says Gavin Schmidt, director of NASA’s Goddard Institute of Space Studies. Although a recent strong El Niño is partly to blame, most of the heat wave has been caused by the trapping of warm air by atmospheric greenhouse gases. With temperatures throughout the first half of the year about 1.5 °C above preindustrial times, it may prove difficult to achieve the 2 °C limit on global temperature that was set for the 21st century by world leaders at last year’s Paris climate talks.

Hawking radiation–like effect seen around artificial black hole

16 August 2016

Nature: One of Stephen Hawking's most famous predictions is that black holes evaporate and disappear due to the emission of radiation. That radiation has not been spotted directly, but now an analog to the phenomenon has been detected escaping from an artificial black hole. Created by Jeff Steinhauer of the Technion–Israel Institute of Technology in Haifa, the so-called black hole is a Bose–Einstein condensate (BEC) of supercooled rubidium atoms. The event horizon is created by accelerating the atoms until they exceed the speed of sound in the medium. Steinhauer says that the BEC then experiences quantum fluctuations of pairs of entangled phonons on either side of the event horizon.

Plasma discharge for food sterilization

15 August 2016
For effective decontamination, bacteria on food surfaces must receive sufficient exposure to lethal agents.

Saturn moon may have methane-filled canyons

15 August 2016
New York Times: NASA’s Cassini spacecraft has pinged Saturn’s largest moon and found deep canyons probably filled with liquid methane. By bouncing radar signals off the moon’s surface, Valerio Poggiali of Sapienza University of Rome and colleagues were able to determine that the canyons are about 1600 m wide and up to 570 m deep. Based on reflections off the canyons’ surfaces, the researchers say the canyons could be filled with liquid, probably the same as that filling the nearby sea into which the channels flow. Because of Titan's extremely low temperatures, methane can exist as liquid, ice, and vapor, much like water does on Earth.

NASA's asteroid-sampling mission to launch in September

15 August 2016
Ars Technica: On 8 September, NASA's OSIRIS-REx spacecraft is scheduled to launch aboard an Atlas V rocket on a two-year journey to the asteroid Bennu. The probe will orbit the 500-m-wide asteroid, taking high-resolution images of the surface and collecting other data. The primary mission of sample return begins nearly two years after the initial data-taking phase. The probe will use a 3 m arm to collect at least 60 g of surface material. The goal is to compare the composition of a pristine asteroid with the remnants of asteroids that have fallen to Earth as meteorites. In a previous mission, Japan's Hayabusa spacecraft managed to grab only about 1500 grains from a stony asteroid. Bennu, on the other hand, is a carbon-rich asteroid. Such asteroids are considered a possible source of Earth's hydrocarbon molecules.

Neutrino oscillations provide hint of antimatter imbalance answer

15 August 2016

Nature: One explanation for the dominance of matter over antimatter in the universe is that a superheavy primordial particle cousin to neutrinos decayed in a matter-favored process. The Tokai to Kamioka (T2K) experiment is designed to test that proposal by measuring neutrino oscillations—when one of the three flavors of neutrino turns into another. Muon neutrinos and antineutrinos are shot from the Japan Proton Accelerator Research Complex to the Super-Kamiokande detector 295 km away. Over six years of operation, the researchers expected to see 24 electron neutrinos and 7 electron antineutrinos. (The disparity exists because antimatter is harder to produce and detect.) Instead, T2K scientists have seen 32 electron neutrinos and 4 electron antineutrinos. That signal is intriguing but well below the threshold needed to rule out statistical variation. T2K would need to produce 13 times as much data to come to a solid conclusion but is slated for only five more years of operation. However, a second, similar experiment called NOvA at Fermilab will switch from shooting neutrinos to antineutrinos next year. The two groups intend to combine their data and expect to have enough to produce a 3 σ signal by 2020. It will take the next generation of neutrino experiments to reach the 5 σ level required to announce a discovery.

US officials express opposition to Obama’s “no first use” nuclear proposal

15 August 2016
Wall Street Journal (via MarketWatch): With just a few months left in office, President Obama may have to give up on the “no first use” proposal he is considering, whereby the US would use nuclear weapons only if it were attacked with nuclear weapons. Among those opposed to the plan are several key cabinet members, including Secretary of State John Kerry, Secretary of Defense Ash Carter, and Secretary of Energy Ernest Moniz. The officials say that US allies such as the UK, France, Japan, and South Korea rely on the US for their security. Were the US to adopt such a policy, those countries might feel the need to develop their own nuclear programs. In light of the opposition the plan has met, it appears unlikely that Obama will press the issue.

Weeding out gender bias in computer software

12 August 2016
NPR: Computer scientists are making the troubling observation that sexual and racial biases are creeping into the output of programs designed to process human language. Adam Kalai of Microsoft and his colleagues, who have been developing a process called word embedding, discovered the problem when they used their algorithm to solve analogies. Based on its study of hundreds of thousands of articles on such sites as Wikipedia and Google News, the word-embedding algorithm suggested, for example, that “he” is to “she” as “brilliant” is to “lovely” or as “computer programmer” is to “homemaker.” Such biases could prove problematic, as when a computer is used for sorting through piles of resumés looking for ideal job candidates. But bias isn’t necessarily bad; for example, pharmaceutical companies may well want to address certain products to either men or women. Therefore, rather than offer de-biased word embeddings themselves, the researchers have developed a technique that leaves it up to individual users to determine “what is a good bias and what is a bad bias,” Kalai says.

Using smartphone data to predict weather

12 August 2016
The Atlantic: The more weather sensors there are on the ground, the more accurate the weather forecast. With the recent explosion of smartphones all over the world, weather forecasters hope to take advantage of the barometric pressure sensors included by many manufacturers. Although intended for location tracking, the sensors could provide useful data on local weather conditions. Because of privacy issues, use of such sensor data has so far been limited, but a few apps are beginning to allow users to share with researchers the data from their phone’s sensors. One such researcher is Cliff Mass (University of Washington), who uses the 5000–10 000 readings per hour he receives from users of the WeatherSignal app to fine-tune the weather-pattern algorithms he’s developing. Such data harvesting works well in highly and even moderately populated areas, Mass says, but he'd like to see at least one sensor per square mile in more rural areas.

Should math instruction switch to “adult arithmetic” and “citizen statistics”?

12 August 2016
Political scientist Andrew Hacker advocates ending requirements for geometry, algebra, trigonometry, and calculus.

Future of Egyptian science hub in question following Nobel laureate's death

12 August 2016
Nature: Ahmed Zewail, an Egyptian-born American, was the first Arab to win a Nobel Prize in the sciences. In 1999 he proposed establishing a university and science hub near Cairo as a flagship project for Egypt's domestic research efforts. After delays stemming from the country's political instability and bureaucracy, the Zewail City of Science and Technology finally opened in 2011. In the five years since, the project's leaders have had trouble funding campus construction and providing scholarships to students. Last week, Zewail passed away at the age of 70. His influence was widely considered a driving force for the hub's ability to gain private funding. However, Egyptian president Abdel Fattah el-Sisi has spoken out in support of the institute, saying that construction by military engineers will be completed regardless of funding. Researchers and administrators at the institute expect that they will have to rely on the government for funding, but they are concerned that state support could reduce the institute's unusual level of autonomy in hiring and research focuses.

Unusual meteorite may have come from the Kuiper belt

12 August 2016

New Scientist: In 2000 an unusual meteorite fell onto icy Tagish Lake in British Columbia, Canada. Its composition was significantly different from that of other meteorites that have fallen to Earth. Previous analyses of the meteorite have suggested it is a D-type asteroid, which is rare in the asteroid belt but much more common around the solar system's gas giants. Now Bill Bottke of the Southwest Research Institute in Boulder, Colorado, and his colleagues have suggested that the Tagish Lake meteorite and other similar rocks that have been seen in the asteroid belt might come from the Kuiper belt. The researchers say the movement of the outer planets early in the formation of the solar system could have launched the asteroids inward. If so, the Tagish Lake meteorite could prove to be a handy point of reference for scientists anticipating the New Horizons spacecraft's visit to Kuiper belt object 2014 MU69 in 2019.

Ahmed H. Zewail

11 August 2016