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News Picks

Physics Today’s online staff summarize the most important and interesting news about science from the world's top media outlets.

There are 57 posts for the selected month (January 2015).
January 26, 2015 11:19 AM

Adjusted ice-sheet models more closely match historical records

Ars Technica: Historical records of sea levels during the past several million years show periods during which they were as much as 20 m higher than they are currently. However, when fed climate details from the periods of highest sea levels, current computer models do not match the historical record. To attempt to correct the models, David Pollard and Richard Alley of the Pennsylvania State University and Robert DeConto of the University of Massachussetts Amherst added two physical processes not currently included in the models—hydrofracturing and cliff failures. Hydrofracturing occurs when water fills crevasses in ice sheets to such depth that the pressure from the water breaks the ice sheet even further. Cliff failures occur when a cliff of ice becomes so tall that it collapses under its own weight. Both processes can increase the calving of icebergs from ice sheets. When that occurs near the grounding line, it can accelerate the loss of a glacier trapped behind the sheet. The adjusted model predicted a much quicker and more severe loss of ice sheets, which could account for much of the historical sea-level rise.

January 23, 2015 2:44 PM

Molecular self-assembly may allow for advancements in microchips

MIT Technology Review: As microchips become smaller, photolithography, the current technique for producing them, is reaching its limits in terms of complexity and expense. A group of researchers at IBM has demonstrated a process of molecular directed self-assembly that may provide a method for making significantly smaller microchips. By carefully preparing a set of block copolymers, and guiding the molecules' positioning using existing photolithography methods, the team was able to create circuit features that were separated by just 29 nm. Current methods are limited to separations of 80 nm. The potential increase in density of microchip circuitry could lead to much smaller chips and significant advances in processing power.

January 23, 2015 2:18 PM

Doomsday Clock moves 2 minutes closer to midnight

Science: The Doomsday Clock is maintained by the board of the Bulletin of the Atomic Scientists (BAS) as a representation of how close the world is to a global disaster. On 22 January, BAS executive director Kennette Benedict announced that the organization would be moving the clock hands 2 minutes closer to midnight, setting the symbolic time as 11:57pm. Benedict said that the reasons for the change include the recent stalling in nuclear disarmament talks and the growing threat of climate change. The time change is just the 18th since the clock's creation in 1947. It has ranged from just two minutes to midnight in 1953 to 17 minutes to midnight in 1991.

January 23, 2015 1:20 PM

Two planets may exist far beyond Pluto

Ars Technica: Two new planets may have been discovered—in our solar system. Their presence has been detected through their apparent gravitational influence on a group of space rocks known as extreme trans-Neptunian objects, which orbit the Sun far beyond Neptune. One of the two possible planets, 2012 VP113, was first detected last year and appears to be about 250 astronomical units away; the second orbits at about 200 AU. If the two do indeed exist and turn out to be much more massive than Earth, their existence would contradict current models of the solar system. Further study will be required before the two objects’ status as planets can be confirmed.
January 23, 2015 11:10 AM

To maintain swarm, jellyfish can swim against current

BBC: Jellyfish tend to congregate in large swarms called blooms, comprising hundreds to millions of organisms. Until recently no one knew exactly how they were able to form and maintain those blooms. Now researchers show that jellyfish can sense ocean currents, actively orient themselves, and swim against the current when necessary. Graeme Hays of Deakin University in Australia and colleagues tagged jellyfish with data loggers to measure their acceleration and orientation; the researchers also used floating sensors to monitor ocean currents. Because jellyfish blooms are proliferating and can disrupt human activities such as swimming and fishing, the researchers hope their findings will allow better predictions of bloom magnitude and movements. However, how the jellyfish know what direction to travel is still unknown.
January 22, 2015 4:15 PM

Laser etching renders metals extremely water-repellent

BBC: Metal surfaces etched by femtosecond laser pulses are more slippery than Teflon and have been shown to be very effective at repelling water. They are so hydrophobic that water drops actually bounce off them, says Chunlei Guo of the University of Rochester in New York, one of the authors of a paper published in the Journal of Applied Physics. Because the water droplets also remove dust particles from the surface, the materials are self-cleaning. Guo and his research team think the technique would be useful in developing countries to create hygienic surfaces for medical or sanitary uses.
January 22, 2015 1:24 PM

Israel's arrest of Palestinian physicist spurs international protest

Nature: Imad Ahmad Barghouthi, a theorist who studies space-plasma physics at Al-Quds University in Jerusalem, was detained without charges on 6 December 2014 as he crossed the border from the West Bank into Jordan. In response to Barghouthi's detainment, several international science organizations have sent letters of protest to the Israeli government and to European organizations that provide research funds to Israel. Barghouthi was on his way to Amman to catch a flight to the United Arab Emirates so that he could attend a meeting of the Arab Union of Astronomy and Space Sciences in Sharjah. Since his arrest, he has been held in an Israeli military prison without being charged under a policy that allows Israel to hold a potential security risk for three months. Jawad Boulos, Barghouthi's lawyer, believes that Barghouthi was detained because of statements he made in support of Palestinian activists during Israel's 2014 invasion of the Gaza Strip. Barghouthi is now scheduled to be released on 2 February, but could be held longer.

January 22, 2015 1:23 PM

Senate amends Keystone XL bill to say that climate change is real

Science: The US Senate voted 98 to 1 to approve an amendment to the Keystone XL Pipeline bill that says climate change is real and not a hoax . Proposed by Sheldon Whitehouse (D-RI), the amendment was one of several put forward by opponents of the pipeline, which would bring oil from Canada to the US. However, it was the only one to be approved. Other amendments that further stated that climate change was directly influenced by human activity and pollution had also been proposed. The Keystone XL bill is heavily supported by Republicans, many of whom have dodged the issue of climate change by saying they aren't scientists. Some, such as James Inhofe (R-OK), had called climate change a "hoax" in the past. Before the vote, Inhofe clarified that statement by saying the hoax is that people think that humanity can change the climate.

January 22, 2015 11:15 AM

Strong emotion aids memory

New York Times: In humans, seemingly trivial memories, when associated with a strong emotional response, can be filed away and recalled much later. To study that phenomenon, Joseph Dunsmoor of New York University and coworkers conducted an experiment in which they showed participants a random series of photographs and asked them to categorize each image as either a tool or an animal. They were then shown another series of photos to categorize, but in this second round, half the participants received a mild shock when they saw tools, and half received the shock when they saw animals. In a series of tests to measure how well the participants remembered the photos, the results varied depending on when the test was given. Those who took it immediately remembered as many animal photos as they did tool photos. But those who took the test hours later remembered more items in the category for which they had received a shock.
January 21, 2015 2:40 PM

Senators hope to amend Keystone XL bill with statement on climate change

Science: The first bill under discussion by the Senate in the 114th Congress concerns the construction of the Keystone XL pipeline, which would bring oil from Canada to the US. The controversial bill is supported by the new Republican majority. Those senators who oppose it say the pipeline will exacerbate global warming and are pushing for amendments affirming that climate change is happening, that human activity is driving it, and that Congress should take action to address the issue. The goal of the amendments, says Charles Schumer (D-NY), is to put climate-change-denying senators in an awkward position. If they block the amendments, they could be accused of dodging the issue. If they let the amendments go to a vote, they will be forced to take an actual position on climate change, which could damage their standing with their constituencies.
January 21, 2015 1:55 PM

Micromotors deliver therapeutic materials to mouse’s stomach

BBC: For the first time, powerful microscale motors have been tested in a living organism. Researchers at the University of California, San Diego, report in the journal ACS Nano that they successfully inserted artificial micromotors, consisting of zinc-coated polymer tubes just 20 μm long, into the stomach of a mouse. The zinc reacted with the stomach acid and produced hydrogen bubbles that propelled the tiny machines into the stomach lining. As the machines dissolved, they released their cargo. The researchers believe that such artificial micromotors, which convert energy into movement, could deliver drugs much more effectively than conventional medicines, which rely on passive diffusion. The method could one day be used to treat peptic ulcers and other illnesses.
January 21, 2015 12:35 PM

LHC restart and new underground experiment may be last chance for WIMPs

Nature: Weakly interacting massive particles (WIMPs) are one explanation for the composition of dark matter, the invisible material that makes up 85% of the universe's mass. However, in the past few years several experiments have failed to detect any WIMPs. Although the Large Hadron Collider (LHC) at CERN was thought capable of creating the particles during its previous run at 8 TeV, it did not. The most sensitive direct detection experiment yet, the Large Underground Xenon (LUX) project, also failed to find any candidate events during its first run in 2013. It's possible that the existence of WIMPs could be ruled out soon if neither the LHC, with an upgraded target collision energy of 14 TeV, nor XENON1T, a direct detection experiment 50 times as sensitive as LUX, finds any. If so, that would open the door to other possible dark-matter explanations that had been considered more "exotic" than WIMPs.
January 21, 2015 11:40 AM

X-ray imaging reveals ancient writing on charred papyrus scrolls

Los Angeles Times: In AD 79 when Mount Vesuvius erupted, it destroyed several ancient Roman towns, including Herculaneum, which had a extensive library. The blast of heat from the volcano carbonized, but did not completely destroy, the library's hundreds of handwritten papyrus scrolls. Discovered almost 300 years ago, the papyri are too damaged and fragile to be unrolled and read, although several attempts have been made. Because the ink used was carbon based, it has proven almost impossible to distinguish between it and the baked paper, even with such sophisticated techniques as x-ray computed tomography. Now Vito Mocella of the Institute for Microelectronics and Microsystems in Naples, Italy, and colleagues have tried a different technique, x-ray phase-contrast tomography, with which they have been able to make out a few words and letters by differentiating among phase shifts in the x-ray light as it passes through the different materials. The researchers hope the technique will open up new opportunities to read other ancient papyri and learn more about ancient Greek literature and philosophy.
January 20, 2015 2:19 PM

Earthquakes shown to release some greenhouse gases

Science: Tetrafluoromethane (CF4) is a greenhouse gas that persists in the atmosphere for 50 000 to 100 000 years. It is commonly produced by the weathering of granite and other metamorphic rocks by rainfall. Now Daniel Deeds of the US Geological Survey and his colleagues have discovered that CF4 is also produced by tectonic activity. Surprised to find the chemical in groundwater samples collected near an active fault in the Mojave Desert, the researchers then examined 14 samples taken from aquifers along part of the San Andreas Fault. All but one of the samples showed higher CF4 levels than did water that had been exposed to the air. That suggested the gas was being absorbed from stone deep underground. The researchers also found that the samples from closer to the fault had higher concentrations of the gas than did those from farther away. Whether the CF4 is produced by the fracturing of rocks during earthquakes or by pressure stresses is not clear. However, the discovery that CF4 levels are not exclusively tied to weathering means they are no longer a reliable indicator of past changes in climate.

January 20, 2015 2:15 PM

Artificial heart recipient able to return home

New York Times: An artificial heart manufactured by French company Carmat has been successfully implanted in a second human patient. Created by French surgeon Alain Carpentier, the device was first used in 2013 when it was implanted in a terminally ill 76-year-old man, who survived for 74 days. The second patient, a 68-year-old man, underwent surgery in August 2014 and is now doing so well that he has been released from the hospital and sent home. The device is made from both synthetic materials and animal tissues and requires an external battery pack. Because there are so many more people needing heart transplants than there are available organs, the artificial heart could extend the lives of those who are diagnosed with heart failure and have no other options.
January 20, 2015 12:25 PM

Scientists discuss start of a new, human-dominated epoch

Nature: An international group of scientists is planning to introduce a new unit of geologic time—the Anthropocene—to cover the period when humans began to have a widespread impact on Earth’s climate, land, and oceans. Although global changes suggest that an epoch-scale boundary has been crossed, where exactly to set that boundary has been a matter of debate. Among the proposals is the dawn of agriculture, the Industrial Revolution, or the first atomic bomb blast, which spread radioactive elements around the world. In 2016 the working group plans to present its formal recommendation to the International Commission on Stratigraphy, which will be the final arbiter in deciding whether and how to define the Anthropocene.
January 20, 2015 11:36 AM

Fast radio burst seen in real time

New Scientist: The first fast radio burst (FRB) was detected in 2007, and eight more have been seen since then. However, all were found after the fact in recorded data. Now, using the Parkes Telescope in New South Wales, Emily Petroff of Swinburne University in Melbourne, Australia, and her colleagues have seen one occurring in real time. FRBs are massive radio pulses that last just a millisecond but release as much radio energy as the Sun does in an entire day. The source of these events is still unknown, but it has been proposed that they could be caused by the collapse of oversized neutron stars or by flares from neutron stars with extremely strong magnetic fields. Within seven hours of the detection by Petroff's team, other telescopes were pointing in the direction of the event. Because none detected  any evidence of an afterglow, two possible sources—gamma-ray bursts and supernovae—have been ruled out.

January 16, 2015 4:12 PM

NOAA and NASA agree: 2014 was the warmest year on record

Washington Post: This morning officials from NASA and the National Oceanic and Atmospheric Agency hosted a joint press conference to announce that the agencies' analyses of 2014 temperature data showed that the year was the warmest yet recorded. Both agencies indicated that the warming was driven by heat from the oceans, which were also the hottest ever recorded. Perhaps most notable about 2014's warmth is that it occurred without an El Niño event, which the other recent years of high warmth all had. In both analyses, the global average temperature was just fractionally warmer than the previous warmest years. The continued warming adds further support for the effects of human-driven climate change.

January 16, 2015 1:57 PM

MacMillan, publisher of Nature, merging with Springer

Science: MacMillan Science and Education, the London-based publisher of Nature and Scientific American, is owned by Holtzbrinck Publishing Group in Germany. Berlin-based Springer Science+Business Media, purchased in 2013 for nearly $3.8 billion by private equity firm BC Partners, is one of the world's largest science, technology, and medicine publishers. Yesterday, the two publishers announced that they would be merging in a deal that would see Holtzbrinck maintain 53% ownership of the joint company with BC Partners holding the rest. Combined, they estimate annual sales of $1.75 billion, a market value of more than $5.8 billion, and more than 13 000 employees. Ewald Walgenbach of BC Partners says the goal is to sell the company, most likely as a publicly traded company, within the next few years. 

January 16, 2015 12:49 PM

Geese use dive-and-glide flight to save energy

NPR: Every year, the bar-headed goose migrates from the Indian subcontinent to central Asia and back, flying over the Himalayan mountains along the way. Charles Bishop of Bangor University in the UK and his colleagues began tagging and tracking the geese on their migrations and discovered an unusual behavior. Instead of reaching and maintaining a high altitude, the geese stayed relatively close to the surface, climbing and diving along the contours of the mountains. The trackers the researchers put on the geese recorded not just altitude but also wing-beat frequency and heart rate. Bishop's team was able to determine that the climb-and-dive pattern reduced the energy that the geese had to exert in comparison to level flight. The thinner air at higher altitudes required an increase in wing-beat frequency, which translated to a significant increase in heart rate. By diving and gliding, the geese could travel farther with less flapping.

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