# 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 19 posts for the selected month (February 2016).

February 5, 2016 4:00 PM

### Carbon storage from reforestation may be offset by shift in tree type

Nature: From 1750 to 1850, nearly 200 000 km2 of forest were cut down in Europe. In the 160 years since, forests have reclaimed an area more than twice as large and now cover 10% more land than they did in 1750. However, the amount of carbon stored in those forests is 3.1 billion tons lower than what was stored in 1750. According to Kim Naudts of the Max Planck Institute for Meteorology in Hamburg, Germany, and her colleagues, it appears that the difference is likely due to the shift from deciduous trees to conifers in an area covering 633 000 km2. Naudt's team says that the shift was caused by timber harvesting and replanting, which favors conifers because of their fast rate of growth.

February 5, 2016 3:00 PM

Science: Founded in 1958, the Defense Advanced Research Projects Agency (DARPA) has earned a reputation for its unique approach to research and out-of-the-box thinking. “The public gives DARPA $3 billion a year, in round numbers, and every decade out pops an Internet, or synthetic biology, or carbon nanotubes, or another significant technology,” says Zach Lemnios, the Pentagon's chief technology officer during the first Obama administration. The key to DARPA’s success, according to people who have worked for or with the agency, is its group of some 100 program managers, who decide which projects DARPA will address. In this Science article, Jeffrey Mervis talks to one of those former managers, mathematician Benjamin Mann, about what led him to join DARPA and his experience with and unique insights into the agency. February 5, 2016 2:40 PM ### Smart contact lenses being developed for medical and recreational use Daily Mail: Instead of toting around bulky devices to monitor health and wellness, browse the internet, or watch videos, people may one day be able to just pop in contact lenses. A number of projects are in the works, among them one by researchers at the University of South Australia who have been developing a prototype that integrates a biocompatible, conducting polymer within a hydrogel. The researchers have succeeded in containing the electrical current within the hydrogel, which is essential to prevent the current from coming into contact with the wearer’s eye. A lens made from such a material could act as a simple sensor, such as for detecting blood glucose, or as a full-blown electronic display. Other potential uses for smart lenses include gathering data about the wearer’s environment, such as the presence of allergens like grass or tree pollen, and reading QR codes or barcodes. February 5, 2016 2:16 PM ### Experts tell Congress that NASA's plan to reach Mars is in trouble Ars Technica: For the past five years, NASA has stated that one of its primary goals is crewed missions to Mars. On Wednesday, a House space subcommittee heard comments from three outside experts about NASA's plans. John Sommerer, who was the chair of a National Research Council panel that reviewed NASA's human spaceflight programs in a 2014 report, indicated that to meet the agency's goals would require roughly$500 billion over the next 20 to 40 years. In contrast, NASA director Charles Bolden and other agency officials have said that they are comfortable with the agency's current budget for human exploration, plus increases for inflation, which only totals to \$180 billion over 20 years. However, that amount would not allow for continued support of the International Space Station. Tom Young, former director of NASA's Goddard Space Flight Center, agreed with Sommerer that NASA does not have a clearly defined plan for reaching Mars. Young and Sommerer said that NASA would need to either receive a significant budget boost or narrow its focus and shift funds away from other programs.

February 4, 2016 3:41 PM

### Researchers use visible light pulses to catch electrons in the act of emitting photons

New Scientist: In 2008, Eleftherios Goulielmakis of the Max Planck Institute of Quantum Optics in Garching, Germany, and his colleagues created the shortest ever pulses of light, with a duration of just 80 attoseconds (10−18 s). However, they used extreme UV (EUV) light, which is so energetic that it can strip electrons away from an atom entirely, rendering it useless for measuring the responses of electrons to outside stimuli. Now, Goulielmakis's team has created the shortest ever pulses of visible light, with a duration of 380 attoseconds. Visible light does not strip electrons from around an atom; rather, it excites them just enough that they emit their own photons. The attosecond flashes were created by merging light pulses that were the same wavelength but slightly out of phase. Their interference cancels out all but small parts of the pulses. The 380-attosecond pulse was short enough to act like a camera flash, which allowed the researchers to catch the emission of UV photons from electrons orbiting krypton atoms. That emission took place just 115 attoseconds after the electrons were excited. It is the first time that researchers have been able to both excite an electron to emit a photon and directly measure the time it takes.

February 4, 2016 3:25 PM

### Researchers work to improve fuel cells for cars

IEEE Spectrum: Several research groups are experimenting with different materials and methods for converting solar energy to hydrogen fuel. One team at the University of California, Berkeley, has been working on improving the efficiency of its photoelectrochemical cell (PEC) by mixing different materials, one to absorb sunlight and the other to conduct electricity. The Berkeley researchers have found some success by coating the titanium dioxide nanowires in the photoanode with bismuth vanadate but are continuing to experiment to find a combination that works even better. A group at Duke University is trying to come up with a fuel, such as methanol or ethanol, that is easier to use, transport, and store than hydrogen, which they could then convert to hydrogen right at the fuel cell. And researchers at Nanyang Technical University in Singapore are working to improve the semiconductor photoelectrode in a PEC through the manufacture of artificial opals, which are natural photonic crystals, to capture a wider sample of the solar spectrum.
February 4, 2016 3:10 PM

### University learning assistant program strives to improve STEM teaching

NPR: The University of Colorado Boulder has launched a program that hires and trains undergraduate students in science, technology, engineering and mathematics (STEM) studies to provide academic support to their fellow students. One of the leading proponents is Steven Pollock, who 15 years ago switched his research specialty at Boulder from nuclear physics to the teaching of physics. Pollock says one of the purposes of the Learning Assistant Program is to improve the quality of undergraduate science education, which has traditionally relied on passive, lecture-based teaching methods. Instead, the program pushes for more research-driven teaching techniques as well as small discussion groups, labs, and demonstrations that are facilitated by the learning assistants. A further goal is to recruit future K–12 STEM teachers from the pool of assistants. Results so far have proven positive, and other colleges and universities have joined the Learning Assistant Alliance.
February 4, 2016 11:54 AM

### Study shows that characteristic surface wrinkles of the human brain are due to physical forces

Guardian: Forty years ago a theory was proposed that the wrinkles on the outer layer, or cortex, of the human brain formed during fetal development because of differential growth rates and the constraints of the size and shape of the skull. A team led by Tuomos Tallinen of the University of Jyväskylä, Finland, has tested the theory for the first time. The researchers used a 3D printed model of a 22-week-old fetal brain before any wrinkling had occurred. The model was made of a soft polymer core coated with an absorbent elastomer gel that represented the cortex. When placed in a solvent, the elastomer swelled and buckled because of its attachment to the core, which restrains the expansion. The result was short furrows that elongated and then formed into the characteristic junctions and bends seen in real brains. When Tallinen and his team members modelled the process mathematically and compared the model with images of different stages of fetal brain development, they saw a distinct similarity. Although the process doesn't match the volume or surface-area increases seen in real brains and doesn't account for the external limitations imposed by the skull, it does provide potential insight into the mechanics of brain growth.

February 3, 2016 1:42 PM

### Light from black hole jets appears to be from circularly moving electrons

BBC: The supermassive black hole at the center of galaxy Pictor A produces two jets of extremely bright x rays that extend three times the width of the Milky Way. The jets were originally revealed by the Chandra X-Ray Observatory, but what made them so bright could not be determined because the pictures of the galaxy were not of high-enough resolution. Now Martin Hardcastle of the University of Hertfordshire, UK, and his colleagues have combined 15 years of x-ray data from Chandra with radio images created by the Australia Telescope Compact Array. The resulting images, whose resolution is five or six times better than that of the best previous images of Pictor A, reveal new details and allow a better examination of the physics at play in the jets. Based on the images, Hardcastle's team believes that the light being emitted from the jets is caused by electrons that are being accelerated in very tight circles similar to the way they are in synchrotrons on Earth. However, what is causing the electrons to be reaccelerated along the full length of the jets isn't clear.

February 3, 2016 12:50 PM

### US works to implement earthquake early warning system

NPR: Similar to a system already in place in Japan, ShakeAlert is being developed by the US Geological Survey and a coalition of university partners to provide early warning of seismic events for the earthquake-prone US West Coast. When an earthquake occurs, it releases energy in the form of seismic waves. The fastest, called P waves, cause little damage but can be used to estimate the location and magnitude of the quake. The goal is to then send out a warning to people in the affected area before the more damaging waves, called S waves, arrive. Because the entire event takes place in just seconds, ShakeAlert’s developers have been working to add more sensors and develop faster computers in order to decrease the processing time and get the alerts out as quickly as possible.
February 3, 2016 11:35 AM

### Flint water crisis highlights problems in government science agencies

Chronicle of Higher Education: It took a professor from Virginia Tech to point out the problems with the water in Flint, Michigan, and to get local, state, and federal officials to do something about it. More than a decade earlier, Marc Edwards, an expert on water corrosion in plumbing, had proved that lead was seeping into the municipal water supply for Washington, DC. However, it took years of crusading to force the government to take action. In 2015 he was called to take on a similar challenge in Flint, where the city government was assuring its residents that the water was fine despite evidence to the contrary. In this interview, Edwards discusses how in both instances, government science agencies failed the local citizens by ignoring or covering up the problem. The result, he says, is a growing distrust among those citizens of their government officials and scientists. He hopes that his victories will inspire other scientists to work to pursue the truth and help people even if it means challenging the government and facing potential legal battles and other problems.
February 2, 2016 2:57 PM

### Mineral record suggests volcanoes are primed for eruption on relatively short time scale

BBC: Volcanoes are always leaking gas, but a specific change in the composition of the gas could provide an early warning sign that an eruption is imminent. David Pyle of Oxford University and his colleagues examined the dormant Campi Flegrei volcano near Naples, Italy, which last erupted in 1538. They were looking for bubbles of gas that were trapped in molten rock shortly before the eruption. By comparing the composition of the gas in those bubbles with that of gases trapped at other times, the researchers reconstructed the magma's evolution leading up to the eruption. The models revealed that the composition of the gas changed significantly in a relatively short period of time before the eruption. Finding similar evidence at other volcanoes will be necessary to support the theory. If fluctuating gas compositions are a common pattern, monitoring volcanic gas could prove useful for identifying potential eruptions ahead of time.

February 2, 2016 2:56 PM

### Silica nanoparticles turn water into moldable substance

New Scientist: Coating water droplets with hydrophobic powder creates opaque, liquid marbles. Now a team led by Xiaoguang Li of Tongji University in Shanghai, China, has extended that technique by replacing the hydrophobic powder with 20-nm silica particles. Because of the thinness of the silica layer, the water droplets remain transparent. And unexpectedly, the silica particles have the ability to jam together, which allows the researchers to mold the water droplets into almost any shape. They have demonstrated how the new material can be sliced like Play-Doh, formed into words, and even used as a convex lens. Further, the researchers discovered that chemicals added to the water diffused slower than normal, suggesting that the droplets might server as miniature test tubes.

February 2, 2016 12:45 PM

### Moon can affect rainfall on Earth

NPR: Not only does the Moon affect Earth’s tides, but now it has been shown to affect the planet’s weather patterns as well. In an earlier study, Tsubasa Kohyama and John Wallace of the University of Washington had noted that the Moon’s position affects the air pressure on Earth’s surface. In their latest study, which has been published in Geophysical Research Letters, the researchers examined satellite data and found a correlation between the presence of the Moon directly overhead and a slight dip in rainfall on Earth’s surface. The reason, they say, is that the Moon’s gravity pulls on Earth’s atmosphere, which causes an increase in air pressure and a corresponding rise in temperature. Because warmer air holds more moisture than cooler air, there is less chance of precipitation.
February 2, 2016 11:05 AM

### France plans to pave roads with solar panels

EcoWatch: To supply green electricity to millions of its citizens, France is embarking on a project to pave its roads with solar panels. Consisting of 7-mm-thick sheets of polycrystalline silicon, the panels are coated with resins and polymers to make them rainproof and sturdy enough to withstand snowplows and foot and vehicle traffic. Although not a new concept, photovoltaic pavement has so far been implemented in just a handful of countries, such as the Netherlands, whose SolaRoad has been operating since November 2014.
February 1, 2016 4:40 PM

### Germany wrestles with its nuclear waste

New Scientist: Although Germany is scheduled to shut down its nuclear reactors by 2022, its nuclear problems are only beginning. An abandoned underground salt mine that was turned into a nuclear waste dump in 1967 is now collapsing, and radioactive residues are seeping through the cracks. Additional nuclear waste that has been housed in temporary storage will also have to be moved. And once the country’s 17 nuclear plants are decommissioned, there will be even more waste to deal with. Although a Final Storage Commission, composed of politicians and scientists, has been meeting to come up with a solution, no deep burial site is likely to be ready before 2050.
February 1, 2016 4:35 PM

### arXiv screening process called into question

Nature: Nicolas Gisin of the University of Geneva has accused moderators at the arXiv eprint server of blacklisting two of his graduate students. The accusation stems from moderators' refusing to publish two papers submitted by the students. Although the first paper was admittedly controversial, the second was less so. When Gisin asked for an explanation, the moderators refused to provide one. Gisin says that arXiv unfairly dismissed the second paper based on the controversial nature of the first. The accusation has spurred other scientists to push for more transparency in the archive's screening process.
February 1, 2016 2:35 PM

### Proton beam cancer therapy causes fewer severe side effects, says study

Guardian: A new form of radiation therapy for cancer patients is being developed: proton beam therapy. Traditional therapy has involved the use of photon radiation, several beams of which are aimed from different angles to intersect at the cancerous tissue. Because protons have a larger mass, however, they scatter less, and the beam can stay more focused on the tumor, which reduces the toxic side effects to the surrounding, healthy tissue. Following proton-based radiotherapy trials on patients aged 3–21 years with medulloblastoma, researchers at Massachusetts General Hospital say the patients experienced less damage to the heart, lungs, and stomach than those who have received traditional photon-based therapy, and the survival rates were similar.
February 1, 2016 12:10 PM

### Earth and Moon are made of exact same material

Los Angeles Times: Not only is the Moon not made of cheese, but it’s actually composed of the exact same material as Earth, say researchers in a new study published in Science. Scientists have long thought that the Moon formed from a collision between Earth and a protoplanet called Theia some 4.5 billion years ago. The authors of the Science paper say they believe the impact was more than a glancing blow, as had been proposed, and was more likely a head-on crash. They base their finding on the ratio of oxygen isotopes in lunar and terrestrial rocks, which they found to be indistinguishable. That indicates extensive mixing between Earth and Theia, probably due to a “high-energy, high-angular-momentum impact” that allowed everything to melt together.
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