Physics Today Daily Edition

Subscribe to Physics Today Daily Edition feed
Please follow the links to view the content.
Updated: 45 min 48 sec ago

LHC has already produced more than twice as much data in 2016 as in 2015

8 July 2016

Ars Technica: From July to November 2015, the Large Hadron Collider (LHC) produced just over 4 inverse femtobarns of data. In its current run, which began in May, the LHC has already produced 10 fb-1. With several more months to go, LHC scientists expect to receive three times as much data this year as last year. The increase in data should help researchers to verify whether the hint of a new particle in last year's data was an actual signal or just noise. The 2016 data haul could also help researchers to statistically rule out a variety of theorized particles and show major flaws in the models that predict them. On a more concrete level, the data should provide significantly more information about already discovered particles that we still don't know much about, such as the Higgs boson.

Bio-inspired swimming robot is powered by light

8 July 2016

New Scientist: A coin-sized robot created from rat tissue has been shown to swim through an obstacle course when exposed to light. The bioengineered stingray, designed by Kevin Kit Parker of Harvard University and coworkers, comprises a tiny gold skeleton covered with a flexible polymer that is layered with about 200 000 rat heart cells. The researchers tweaked the cells to make them light sensitive. By shining different frequencies of light on different sides of the robot, they were able to affect its speed and direction. The ultimate goal, according to Parker, is to better understand how the heart works and one day be able to build one.

Planet found in surprisingly close orbit to three suns

8 July 2016
Los Angeles Times: Thousands of planets have been found to exist in multistar systems. However, what makes the newly discovered triple-star system HD 131399 stand out is the fact that its planet is located so close to its three stars. Because of the complex gravitational forces involved, scientists had assumed that no planet could maintain a stable orbit in such close proximity to so many stars. “This discovery shows us that planets can form or evolve into these almost unstable systems that previously almost seemed like science fiction,” said the University of Arizona's Kevin Wagner, one of the researchers whose paper detailing the discovery appears in Science.

Dark-matter intrigue

7 July 2016
Extra Dimensions: When it comes to the disputed dark-matter detection claim by the DAMA experiment, science is just part of the story.

UK climate advisory committee approves fracking, with conditions

7 July 2016

BBC: The UK's Committee on Climate Change (CCC) has said fracking in the country can go ahead if three conditions are met: Emissions must be strictly limited at all stages of construction, operation, and decommissioning; total UK gas consumption must not increase, which means shale gas must displace imported gas; and shale gas emissions must be included in the UK's already established carbon budgets. The UK government says it already intends to abide by the restrictions, but environmentalists argue that shale gas production will overwhelm the country's attempts to meet its climate change goals. The CCC predicated its decision on a range of projections for gas production, with the most extreme production model predicting 11 million tons of CO2 emissions per year by 2030. That amount is just one-fourth of the country's emissions from agriculture and land-use change. The government will make its final decision on whether to allow fracking—at two sites in Lancashire—by 6 October.

Before failing, Japan's <em>Hitomi</em> satellite returned data on galactic wind

7 July 2016

New Scientist: In March, just over a month after it launched, the Japan Aerospace Exploration Agency's Hitomi x-ray telescope suffered a failure that rendered it inoperable. Now the satellite team has released a paper showing that Hitomi was able to collect useful information before it died. Andrew Fabian of the University of Cambridge and his colleagues used Hitomi data to map the flow of plasma away from the Perseus cluster of galaxies and out into intergalactic space. Hitomi's images reveal that the flow is massive, with gusts of plasma larger than the Milky Way. The galactic wind is driven by a supermassive black hole located at the center of the cluster's central galaxy. The black hole creates jets of particles that travel near the speed of light and blow cooler gas out of the cluster.

New satellite to monitor Earth’s carbon emissions

7 July 2016
IEEE Spectrum: On 22 June the Claire satellite was successfully launched by Montreal-based developer GHGSat. It is the first of a planned fleet of such satellites dedicated to the remote sensing of greenhouse gas emissions from industrial sites. Claire, which is equipped with an IR spectrometer and telescopic lensing, will fly around the world taking a series of high-resolution aerial snapshots of thousands of sites. The data it gathers will be used to improve emissions reporting, track industrial efficiency, and provide competitive intelligence, says GHGSat president Stéphane Germain.

New Year’s Eve will last one second longer this year

7 July 2016 On 31 December at 23 hours, 59 minutes, and 59 seconds Coordinated Universal Time, one leap second will be added to the world’s official timekeeping system. The reason is to maintain the synchronicity of two types of clocks: atomic clocks, which are based on the vibrations of the cesium atom, and traditional clocks, which are based on Earth’s rotation relative to the Sun. Because Earth’s rotation varies irregularly, the International Earth Rotation and Reference Systems Service, the world's official timekeeper, usually applies a leap second whenever needed to keep the difference between the two time systems from exceeding 0.9 second.

A new, exquisitely precise determination of Planck’s constant

7 July 2016
Once the metrology community has settled on a value, the unit of mass will be redefined.

Jordan seeks nuclear technology deal with the US

6 July 2016

Associated Press: Jordan's nuclear energy program is more than a decade old, but the country still relies on fossil fuel imports to provide 98% of its electricity. Khaled Toukan, chairman of the Jordan Atomic Energy Commission, says his country is negotiating an agreement with the US for access to nuclear technology such as small modular reactors. Currently, Jordan has a $10 billion deal with Russia for the construction of two large reactors to be built by 2025, but the financing isn't settled. If that deal falls through, Toukan still wants the country to go forward with a deal for smaller reactors, which he says could be used for powering desalination plants. The discussions with the US had previously stalled when Jordan refused to rule out uranium enrichment, which can be used for not only generating electricity but also building nuclear weapons.

Wellcome Trust to publish an open-access online journal

6 July 2016

Science: The Wellcome Trust, a London-based charity that is one of the largest nongovernmental sources of funding for biomedical research, is launching an open-access online journal this fall. Wellcome Open Research will feature the work of researchers who are funded by Wellcome Trust grants, and the charity will also cover publishing costs for the authors. This will be the second time the company has been involved in an open-access journal: In 2012 it partnered with the Howard Hughes Medical Institute in Chevy Chase, Maryland, and Germany's Max Planck Society to launch eLife. Wellcome Open Research will function more like the preprint server arXiv than a traditional journal, with authors encouraged to post anything from a full paper to just a data set. Following publication, a publicly selected group of peer reviewers will evaluate and comment on the work. The site will be managed by Science Navigation Group's F1000 publishing service.

Increase in Antarctic sea ice does not contradict global warming

6 July 2016

Washington Post: Even though the area of sea ice surrounding Antarctica has been increasing since 2000 and reached an all-time high in 2014, Earth is still undergoing climate change, according to a recent study in Nature Geoscience. The reason for the increasing Antarctic sea ice is natural climate variability, say Gerald Meehl of the National Center for Atmospheric Research in Boulder, Colorado, and his colleagues. Antarctic sea ice is affected by the interaction of several meteorological phenomena, such as the Interdecadal Pacific Oscillation (IPO) and the Amundsen Sea Low, a climatological low-pressure system off the Antarctic coast. Because the IPO has been in its negative phase, it has been causing the Pacific’s surface to cool, the Amundsen Sea Low to deepen, and local winds to increase; those forces together have resulted in sea ice being pushed away from the Antarctic continent and new ice forming in the gaps. Now, however, the IPO has shifted, and Meehl says Antarctic sea ice will probably “stop growing, maybe start shrinking a little bit.”

UK researchers already feeling impact of Brexit

6 July 2016
BBC: The future of British research is up in the air following the recent decision by the UK to quit the European Union. Although leaving the EU does not necessarily mean leaving its research funding system, uncertainty surrounding Brexit and the ultimate consequences is already causing problems. Researchers in other European countries are asking that some UK researchers withdraw their applications for funding on certain projects. The disruption could affect current and future collaborations, which are critical for the advancement of cutting-edge research.

Optimizing solar cells

6 July 2016
New materials and innovative synthesis methods address problems with solar cell efficiency and cost.

Curbing fraud or restraining speech?

5 July 2016
Reporters and commentators engage the impassioned legal struggle over Exxon and climate.

China builds largest-ever radio telescope

5 July 2016
New Scientist: This week China completed construction of the largest radio telescope in the world, the Five-hundred-meter Aperture Spherical Telescope (FAST). Situated in a crater-like depression in China's southwestern province of Guizhou, FAST comprises 4450 triangular panels that can be rearranged to track radio waves from specific objects, giving the telescope far greater range and sensitivity than other radio dishes. Once it is up and running, FAST will be used to look for pulsars and exoplanets, to detect molecules such as hydrogen in space, and to search for potential electromagnetic signals from extraterrestrial civilizations.

NASA extends missions of nine planetary spacecraft

5 July 2016

New York Times: On 1 July, NASA announced mission extensions for nine current spacecraft that have already completed their primary missions. The New Horizons probe, which flew past Pluto, will continue on to study the Kuiper belt object 2014 MU69. The other funded missions are Dawn, which is orbiting Ceres; the Lunar Reconnaissance Orbiter; the Mars Reconnaissance Orbiter; the Mars Atmosphere and Volatile Evolution orbiter; the Opportunity and Curiosity rovers on Mars; the Mars Odyssey orbiter; and the European Space Agency's Mars Express, for which NASA is providing support. Extensions for most of the missions were expected, but the inclusion of Dawn surprised the team that is managing the mission. The craft is low on fuel because of its reliance on thrusters after the failure of two reaction wheels. Now Dawn will remain in place around Ceres, where it will continue to make observations as the dwarf planet approaches perihelion.

Large data sets overwhelm facial recognition software

5 July 2016

IEEE Spectrum: Many facial recognition algorithms have a success rate above 95% when tested against databases of just a few thousand faces. A new test called the MegaFace Challenge evaluates the performance of algorithms when they are presented with a database of 1 million images of 690 000 people. The challenge is for the algorithms to evaluate whether two different pictures are of the same person and to determine if a given person is in the database. The success rates for all the tested facial recognition programs dropped significantly when faced with so much data. Google's FaceNet, the top-scoring algorithm tested, dropped from near 100% accuracy on the widely used Labeled Faces in the Wild (LFW) test to just 75% on the MegaFace Challenge. Several algorithms that scored above 90% on LFW dropped to below 60% accuracy. Ira Kemelmacher-Shlizerman of the University of Washington in Seattle and his colleagues organized the MegaFace Challenge to evaluate the effectiveness of facial recognition software in more realistic situations.

NASA’s <em>Juno</em> spacecraft achieves orbit around Jupiter

5 July 2016
Nature: On 4 July NASA’s Juno spacecraft successfully entered Jupiter’s orbit. Launched in August 2011, the craft took almost five years to make the roughly 2.7 billion km trip. Juno is to complete two 53-day orbits of the planet before burning its main engine and settling into a shorter, 14-day orbiting pattern. The first spacecraft in more than two decades to visit Jupiter, Juno will investigate the giant planet’s composition, Great Red Spot, and massive radiation belts. The ultimate goal is to gain insight into how Jupiter, and the entire solar system, evolved.

Ice-age temperature swings may have been caused by fluctuating Atlantic Ocean currents

1 July 2016
Science: During the last ice age, temperatures on Earth’s surface seesawed several times between the Northern and Southern Hemispheres: As the north got colder, the south grew warmer, and vice versa. Now researchers have found that the abrupt temperature changes in the two hemispheres may have been caused by a slowdown of the Atlantic Meridional Overturning Circulation (AMOC), an ocean current that drives shallower, warmer waters north and deeper, colder waters south. Studying a sediment core drilled from the Bermuda Rise in the Atlantic Ocean, Jerry McManus of Columbia University and colleagues say they saw at least four instances when the ratio of two radioactive daughter isotopes changed sharply, which indicated a weakening of the AMOC. Such slowdowns could have caused the north to receive less warm water and temperatures there to drop while the south heated up due to the backlog of warm water. What caused the slowdowns is still unknown, but one explanation is the breaking off of Canadian icebergs, whose melting would have increased the amount of freshwater in the North Atlantic and possibly disrupted ocean flow. Over some 1500 years, the freshwater would have dissipated, allowing the AMOC to increase once again in strength.