Physics Today Daily Edition

Subscribe to Physics Today Daily Edition feed
Please follow the links to view the content.
Updated: 3 hours 15 min ago

Beyond 911: Medical applications of mobile phones

17 April 2015
Researchers and entrepreneurs discuss developments in the role of mobile phones for medical imaging and monitoring.

Warm-water anomaly in NE Pacific affecting weather and marine animals

17 April 2015
New Scientist: An extensive “blob” of warm water—some 2000 km wide and 100 m deep—has been lingering off the US Pacific coast for the past year and a half. Between 1 °C and 4 °C warmer than normal, the blob has been affecting water circulation, inland weather, and ocean ecosystems. Researchers studying the anomaly through the use of satellite imagery say it may have been caused by an “unusually strong and persistent” weather pattern that deflected winds and prevented the natural mixing of cooler air and water from high latitudes. Of most concern to scientists is the impact on marine species, which are being forced to adjust to new habitats and feeding patterns.

Arizona court rejects lawsuit concerning access to climate researcher emails

31 March 2015

Ars Technica: An Arizona court has rejected a lawsuit by the Energy & Environment Legal Institute, which sought to gain access to faculty emails at Arizona state universities. After examining sample emails, the court determined that the state's university system had correctly responded to the institute's open-records request. The institute had requested emails from a variety of university faculty members, including two climate researchers: Jonathan Overpeck and Malcolm Hughes. The university system's Board of Regents rejected the request because the emails were private, contained student information, and discussed ongoing research. The institute also lost a similar case in Virginia, which included the emails of climate researcher Michael Mann. The case marks the second time a court has ruled that materials detailing ongoing research projects are not subject to open-records requests.

NASA redefines its asteroid redirect mission

31 March 2015
Is a boulder the same as an asteroid? The space agency seems to think so.

Mercury’s dark surface may be due to cometary dust

31 March 2015

Los Angeles Times: Mercury and the Moon are often compared because they are about the same size and both lack atmospheres. But Mercury is covered in dark material that makes it only one-third as reflective as the Moon. Most airless planetary bodies as dark as Mercury have a high iron content, but Messenger measured the planet’s surface as being just 2% iron. Now, Megan Bruck Syal of Lawrence Livermore National Laboratory and her colleagues believe they’ve found the explanation. They realized that the planet’s dark appearance could be caused by the presence of carbon-rich cometary dust, and their calculations of potential dust impacts revealed that the dust would stay on Mercury’s surface. They also determined that, because the concentration of cometary dust in the solar system is much greater closer to the Sun, Mercury gets hit by 50 times as much dust as the Moon, which explains why Mercury is so much darker. Finally, they found that firing cometary dust-like material at material similar to that found on Mercury’s surface did produce a dark layer on the surface material.

Ants in space adapt to get around

31 March 2015
BBC: Ants work collectively to explore their environment and look for food. But they have no central control directing their movements. To see how ants would function in microgravity, researchers sent eight colonies of 80 common pavement ants to the International Space Station. The ants were confined to small transparent plastic boxes in which a barrier could be removed to allow the ants to spread out and explore a larger area. The microgravity conditions appeared to interfere with the ants’ ability to cling to surfaces, which resulted in their exploring the area less thoroughly and using less direct paths. However, they still managed to show a remarkable ability to not only walk on surfaces but also regain their footing after being sent tumbling through the air, according to the researchers, whose paper appears in Frontiers in Ecology and Evolution. The group’s findings could have many applications, particularly in robotic search and rescue operations.

The evolution of hydrogen on Mars

30 March 2015
New atmospheric maps may disentangle local phenomena from global phenomena in Mars’s water cycle.

New UK policy regarding the media raises concerns for scientists

30 March 2015
Science: A recent change to the UK civil service code has upset members of the country's scientific community, who say it could hinder their communications with the press. According to the new policy, all contact with the media must be approved in advance by the minister of the agency in question. Several of the country’s journalistic and public relations organizations have asked the government to reconsider the change. In an open letter, representatives of the Science Media Centre, the Association of British Science Writers, and Stempra, an organization of science communication professionals, say the new code “will have a negative impact on the public understanding of science and the quality of the public discourse on some of the most important and contentious issues of our times.” The prime minister's official spokesman has countered that the amendment “merely clarifies rules on official contact that were already in place.”

Atlantic Ocean circulation shows “exceptional” slowdown

30 March 2015
Ars Technica: Ocean water varies in salinity and temperature due to many processes, including evaporation, precipitation, freshwater inflow from rivers, and sea-ice melting. Warmer, saltier water mixes with cooler, less salty water because of currents induced by waves, wind, and tides. One such major current, the Atlantic meridional overturning circulation (AMOC), appears to have slowed down markedly in the latter part of the 20th century, according to a recent study published in Nature Climate Change. Stefan Rahmstorf of the Potsdam Institute for Climate Impact Research and colleagues studied the instrumental temperature record from the past 100 years and temperature reconstructions for the past 1000 years. They say that over the 20th century, the AMOC showed a marked slowdown of about 14%, with a particularly low point lasting from the 1970s to the mid 1990s, perhaps because of the melting Greenland ice sheet. Because climate models have not indicated any weakening of the AMOC in the 20th century, it’s possible they are underestimating climate change developments, according to the researchers.

Alpha Centauri may have two Earth-like planets

30 March 2015

New Scientist: In 2012 researchers announced that they may have found a planet orbiting Alpha Centauri B. The finding was based on slight wobbles observed in the star's motion and suggested the planet orbited the star every three days. A subsequent set of observations in 2013 and 2014 by Brice-Oliver Demory of the University of Cambridge and his colleagues, who used the Hubble Space Telescope to look for a dimming of the star's light, revealed a single transit of Alpha Centauri B. However, the duration of the transit was longer than had been predicted for the planet. Demory's team ruled out other phenomena to explain the transit, which suggests the existence of a second planet in orbit around Alpha Centauri B. Confirming the second planet won't be easy because it would require 20 consecutive days of observations with Hubble. Given the many demands for time on the telescope, approval for such a long observation is unlikely.

First commercially available graphene light bulb

30 March 2015

BBC: Graphene, the single-atom-thick arrangement of carbon atoms with a wide range of curious properties, was first isolated at the University of Manchester in the UK in 2004. Now, researchers from the university have contributed to the design of the first commercial consumer product to use graphene: a light bulb with a graphene-coated filament. The increased conductivity of the graphene reduces the bulb's energy use by 10% and lengthens the bulb's lifetime. The bulbs are expected to be available for sale later this year for under £15 ($22), which is less expensive than current LED bulbs.

<em>The Infinite Monkey Cage</em> live—a review

30 March 2015
The BBC’s science and comedy radio show comes to the US for a series of live recordings.

Publisher creates software to detect bogus research papers

27 March 2015
Science: Springer, one of the world's largest publishers of scientific journals, and the Université Joseph Fourier in Grenoble, France, are set to release an open-source piece of software called SciDetect. The software aims to automatically detect papers that are superficially legitimate but are in fact deliberate hoaxes. The need for SciDetect arose, in part, because of another piece of software, SCIgen, that automatically generates such bogus papers. Devised in 2005 by three computer science students from MIT, SCIgen strings together jargon in grammatically correct yet meaningless sentences. The software also generates plots and references. The trio wrote the software to expose the lack of peer-review at certain conferences, but after its release, SCIgen-authored papers ended up in journals, embarrassing Springer and other publishers.

China's reduction in coal power is having significant effect

27 March 2015

New York Times: Coal still supplies two-thirds of China's power generation, but with the nation's economy growing at the slowest rate in 25 years and a mandated shift to nuclear and renewable sources, coal imports and utilization have dropped significantly over the last year. In 2014 the use of fossil fuels to generate power was at a record low of 53.7%, down from 57.3% in 2013. That reduction led to a drop of 18 million tons or 1.3% in the amount of coal used and to a 11% reduction in coal imports by the world's largest coal consumer. The trend is expected to continue through 2015. As a result, the cost of coal from Australia, one of China's primary sources, fell 30% last year to under $60 per ton this month, the lowest since May 2007.

Dark matter even less affected by galactic collisions

27 March 2015

BBC: Observations of 72 galactic collisions have revealed to a higher level of detail than ever before that dark matter is unaffected by any force other than gravity. Richard Massey of Durham University in the UK and his colleagues used Hubble Space Telescope and Chandra X-ray Observatory to observe the collisions in both visible and x-ray light. The x-ray images revealed the movement of the clouds of plasma that reside inside and around galaxies whereas the visible images showed the movements of the stars. The combined images allowed the researchers to measure the gravitational lensing effect of the dark matter. The observations revealed that the dark matter exhibited no sign of non-gravitational interactions with itself or other matter to a much higher level of precision than previous observations.

Restricting global warming to 2°C could still bring harm

27 March 2015
New Scientist: At the climate talks that took place in Copenhagen in 2009, the world's leaders agreed to work toward limiting the globally average amount of warming to 2°C with respect to 1990. But in a new paper published in Climate Change Responses, geographer Petra Tschaker of the Pennsylvania State University advocates a target of 1.5°C. Tschaker contends that the lower target will significantly reduce the impact of climate change, especially on poor and vulnerable communities, such as the Sami people of northern Norway, Sweden, Finland, Russia's Kola Peninsula.

<em>Physics</em>, the album

27 March 2015
A search of a vast music database reveals that just three groups have ever chosen “physics” as an album name.

Black physicists and astronomers: The interviews

27 March 2015
Two students, two research astronomers, and a retired nuclear physicist talk about their professional achievements and aspirations and their love for science.

Saturnian day measured using gravitational field

26 March 2015

Los Angeles Times: In the early 1980s the Voyager spacecraft measured the length of Saturn's day to be 10.6 hours based on the planet's magnetic field. But when Cassini reached the planet in 2004, it obtained a different result. Subsequent measurements revealed that the planet's magnetic field, unlike Earth's, is aligned with the axis of rotation; it cannot, therefore, be used for an accurate measurement. Other techniques that attempted to use the planet's wind patterns proved even less accurate. Ravit Helled of Tel Aviv University and his colleagues have now used Saturn's gravitational field to measure the length of the day, which they found to be 6 minutes shorter than the original Voyager measurement. The technique uses the periodic changes in pull that Cassini feels as Saturn rotates as well as measurements of the planet's oblateness. The researchers confirmed the accuracy of the technique by testing it against Jupiter, whose day has a well-known length.

Water squished between graphene sheets forms "square ice"

26 March 2015

Nature: The oxygen atom in a water molecule is tightly bound to the two hydrogen atoms, but it also experiences a slight connection with the hydrogen in neighboring molecules. Because of this, as water freezes, the molecules arrange themselves into three dimensional tetrahedral shapes. Now, Andre Geim of the University of Manchester, UK and his colleagues have discovered that water pressed between sheets of graphene freezes into an ice in which the molecules form two-dimensional layers of square shapes. The structure could be the 18th different type of water ice discovered. Geim's team calculated that the pressure exerted on the water by the graphene sheets exceeds 10 000 atm or 1 gigapascal.

Pages