Welcome to the Saturday Science Edition of Overnight News Digest
Overnight News Digest is a regular daily feature which provides noteworthy news items and commentary from around the world. The editorial staff includes side pocket, maggiejean, wader, Doctor RJ, rfall, and JML9999.
Neon Vincent is our editor-in-chief.
Special thanks go to Magnifico for starting this venerable series.
Astronomy
Hacking the Cosmos: Event Hopes To Solve Complex Data Challenges
Last week, astronomers, astrophysicists, data scientists and programmers came together at New York University to try to solve some of astronomy's toughest problems — in just five days. The event, called Astro Hack Week, has only one rule: Everybody has to produce something. It might be a build of an astronomy data search algorithm, a series of programming tutorials or a bot that generates fake (and surprisingly plausible) tweets from one of the event creators. It might be planned from the get-go or something dreamed up based on a morning teaching session. But whatever it is, it must be built (or "hacked") entirely at Astro Hack Week and rely on the cooperation of programmers, scientists and engineers at all levels. To deal with the huge complexity of data and simulation in astronomy today, many researchers are turning to data scientists and programmers for inspiration — or becoming programmers themselves. Space.com took a field trip last Thursday (Oct. 1) to see how Astro Hack Week is crafting that transition. [To Find Alien Earths, Scientists Comb Kepler Data (Video)]
"Many of the projects [that] people are working on didn't exist before, let's say, a week ago," said Phil Marshall, a staff scientist at the SLAC National Accelerator Laboratory at Stanford University in California and one of Astro Hack Week's organizers. "And some of them are emerging as we sit here,"
space.com
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A Dusty Mystery Around AU Microscopii
Nearby debris disks — the dusty, sometimes rocky planes circling young stars — have only recently become the hunting grounds of astronomers, who search for the telltale signs of forming planets: gaps, clumps or warped features in these disks. But thus far, very few disks have revealed planets hidden inside. The majority remain a mystery waiting to be unfolded. SPHERE, an instrument mounted on the Very Large Telescope in Chile, is designed to directly image debris disks and reveal their secrets. Its coronagraph blocks the light of the host star, while the instrument’s adaptive optics reveals details around the star to a resolution of 0.5 arcseconds, rivaling the Hubble Space Telescope’s imaging prowess. In 2014, Anthony Boccaletti (Paris Observatory) and his colleagues pointed SPHERE at a test target known as AU Microscopii, a young star 32 light-years away in the southern constellation Microscopium. But what they found was something utterly unexpected: wave-like arches on one side of the disk. Were they real? The team turned to data gathered by the Hubble Space Telescope in 2010 and 2011, and sure enough, the features were there too. What’s more, the arching waves had moved at a breakneck pace through the disk, moving away from the central star at 4 to 10 kilometers per second (between 9,000 and 22,000 mph).
“This is a fascinating result,” says Richard Nelson (Queen Mary University of London), who was not involved in the study. “But interpreting the observations is a real puzzle.” Not only have astronomers never seen anything like it, they really can’t find a viable explanation.
skyandtelescope.com
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Biology
Ornithologists Publish Most Comprehensive Avian Tree Of Life
“Cardinals and woodpeckers evolved from a hawk-like ancestor and most of the world’s water birds also appear to be a close-knit group, indicating one bird group quickly adapted to aquatic environments after most of the dinosaurs died out at the end of the Cretaceous period.” These are among hundreds of other stories that make up the history of birds revealed in a genomic analysis of almost 200 species by a team of scientists from Yale University, Florida State University, North Carolina Museum of Natural Sciences and Cornell University. According to the scientists, all modern birds evolved from the only three dinosaur lineages. [...] In the last ten years, the historical origins of ostriches and their relatives, the emus, have been well established, as it has for ducks, chickens and their relatives. But the evolutionary history of 90 percent of contemporary birds in a group called Neoaves has remained unclear. sci-news.com
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Sea Turtles Face Plastic Pollution Peril
A new global review led by the University of Exeter that set out to investigate the hazards of marine plastic pollution has warned that all seven species of marine turtles can ingest or become entangled in the discarded debris that currently litters the oceans. The research, which was carried out in collaboration with Plymouth Marine Laboratory, North Carolina Wildlife Resources Commission, North Carolina State University, Duke University Marine Lab and James Cook University, is published in the ICES Journal of Marine Science and reveals serious knowledge gaps in the diverse and complex pathways in which plastic pollution can harm marine life.
Joint lead author Sarah Nelms, from the Centre for Ecology and Conservation at the University of Exeter's Penryn campus said: "I was shocked at how little is known about the impacts of plastic on marine turtles." "We know that discarded plastic poses a serious threat to wildlife, but this study shows that more research is urgently needed if we are to understand the scale of the problem."
Annual global plastic production has grown from 1.5 million tonnes to 299 million tonnes in the last 65 years and as a result plastic pollution is increasing, both on land and at sea.
Prof Brendan Godley, who led the team said: "When turtles ingest plastic, they can suffer intestinal blockage that can result in malnutrition which can in turn lead to poor health, reduced growth rates, lower reproductive output and even death." "It is sobering to think that almost every piece of plastic that ever entered the sea is still there; breaking down and forming a vast soup of microplastics that could have frightening long-term repercussions."
sciencedaily.com
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Chemistry
Building A Better Magnesium Battery
Magnesium is a promising battery material because of its high energy-storage capacity and its safety profile, making it particularly attractive for powering electric vehicles. Practical magnesium battery systems, though, have eluded researchers. Such batteries are now a step closer: By adding a lithium salt to the electrolyte, researchers have made a promising prototype of a high-capacity, rechargeable magnesium battery. [...] In theory, a battery with a magnesium anode and a sulfur cathode can store four times as much energy as a commercial lithium-ion battery—about the same capacity as experimental batteries that use pure lithium-metal anodes paired with sulfur. But batteries that use bare lithium metal are dangerous: Over cycles of discharging and recharging, the metal dissolves from the anode and replates onto the cathode, forming sharp spikes called dendrites. These dendrites eventually can bridge the two electrodes and cause electrical shorts, leading to fires. Other metals, including magnesium, don’t form dendrites, so they’re considered safer. Matching a magnesium anode with a good-performing cathode and electrolyte has been tricky. In 2000, researchers at Bar-Ilan University, in Israel, made the first rechargeable magnesium battery [...] This work showed that it was possible to make a magnesium battery rechargeable, but they paired the metal with a low-energy-density cathode. In 2011, another team made the first magnesium-sulfur batteries. [...] The switch to a better cathode led to improvements in energy density, but these batteries weren’t truly rechargeable, says Chunsheng Wang, an electrochemist at the University of Maryland, College Park. After two uses, these Mg-S batteries lost about 70% of their storage capacity: The sulfur and the magnesium react to form insoluble sulfide compounds, depleting the active parts of both electrodes. cen.acs.org
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And The Time Of Death Was?
Monitoring changes in body temperature, as well as the stages of rigor mortis are among the traditional methods currently used to estimate the PMI. But environmental fluctuations, such as temperature, can impact the rate at which these changes occur, reducing their reliability. Ricardo Jorge Dinis-Oliveira, from the University of Porto, describes a common scenario where in a court of law the judge asks ‘what was the time of death?’ A method that yields an accurate result to this question would be ‘the Holy Grail of forensic sciences’ according to him. Now, Dinis-Oliveira’s group has monitored how the pH, and concentration of 46 biochemicals, including lipids and proteins, fluctuates as blood decomposes, to calibrate a mathematical model that can estimate the PMI. The current model is based on blood samples from living humans but the team’s next step will refine the model using samples taken from corpses with a known time of death. When asked about the future of his work, Dinis-Oliveira says it ‘may provide a new paradigm for estimating the post-mortem interval and become a complementary procedure for the methodologies already used’. rsc.org
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Earth Science
The Relationship Between Carbon Cycles And Climate
Making predictions about climate variability often means looking to the past to find trends. Now paleoclimate researchers from the University of Missouri have found clues in exposed bedrock alongside an Alabama highway that could help forecast climate variability. In their study, the researchers verified evidence suggesting carbon dioxide decreased significantly at the end of the Ordovician Period, 450 million years ago, preceding an ice age and eventual mass extinction. These results will help climatologists better predict future environmental changes. The Ordovician geologic period included a climate characterized by high atmospheric carbon dioxide (CO2) levels, warm average temperatures and flourishing life. Near the end of the period, CO2 levels dropped significantly but precisely when and how fast is poorly known. Kenneth MacLeod, a professor in the Department of Geological Sciences in the MU College of Arts and Science, directed a research team studying the climate changes 450 million years ago to better understand the interactions among the biosphere, the oceans, atmospheric CO2 levels, and temperature.
"Climate is not a simple science; many small factors determine what exactly leads to global warming and cooling trends," MacLeod said. "By understanding the deep past, we have better information about historic trends that lead to better predictions. Understanding carbon cycles adds value to our knowledge base of climate change."
During the Late Ordovician period, most of North America was covered in a shallow tropical sea. What is now Alabama was on the margin of that sea where local environmental effects likely did significantly impact carbon cycling. Page Quinton, a doctoral student in MU's geological sciences program, led a field research team in northeastern Alabama that collected rock samples from rock formations exposed when workers cut highways through hills in the region. Using the samples, Quinton analyzed them for chemical clues that can be related to CO2 levels at specific time periods.
"After examining rocks 450 million years old or older, we believe the drop was caused by a massive burial of organic carbon during the time period," Quinton said. "We're trying to determine whether or not there was an increase in plant productivity, or huge algae blooms in the ocean, that died and fell to the sea floor, basically burying CO2. This burial, coupled with the mountain building event that created the Appalachian Mountains, could have contributed to the resulting ice age."
enn.com
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Rainforest Fragments And Species That Need Them!
Global cover of forest is well-known to be decreasing at an alarming rate. Assessing the current situation is always liable to leave the assessors bemoaning their state of out-of-datedness!. On 20th March, however, several prominent ecologists released their research on just how threatened and lacking in biodiversity our native woodland is becoming. 70% of the remaining forests are only 1km from the edge of the forest, meaning they must look mightily skinny. Over 5 continents and many different biomes over 35 years, that creates a crazy image of lost bits of habitat, isolated like sorry islands in a sea of human development. The smallest of these pieces of woodland are not alone, as they biodiversity has been reduced everywhere by between 13 and 75%, with increases in all cases as time passes. Restoration and reconnection with wildlife corridors is urgent to prevent many extinctions such as tigers in India or much smaller species that rely on a tiny area to provide their needs in a habitat. If we wipe out one plant area or one ant, for example, we lose a butterfly species such as the large blue, Phengaris arion. Using a brand-new high resolution map of global tree cover, the forest border figures were obtained. The Amazon and Congo Basins remain as the only pieces of contiguous forests in the world, despite their fast disappearance. SE Asia, New Guinea and the northern taiga forests are the only others left. The Brazilian Atlantic Forest is an object lesson, being now largely deforested, reduced from having 90% of the trees more than 1km from the forest edge to only 9%. As fragmentation has a large role in reducing population sizes below any viable level, corridors have become essential for organisms that can actually use them. The edge of a forest is a very dangerous area for predation of all types, with fledgling birds an obvious example. This means bird species can be reduced in numbers so badly that extinction looms over their obvious lack of future breeding success. Fragmentation was shown in the study to cause species richness of most groups of organisms to decrease by between 20 and 75%. Effects could be immediate, or they could become greater over time. Bird species in some areas declined by 50% over either 5 years or 12 years, depending on the habitat fragment size. Arthropod species richness in another area declined by between 26 and 40 % after only 1 year. earthtimes.org
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Physics
Researchers Settle Long-Standing Debate About Fundamental Behavior Of Shaking Particles
Particles floating in fluid perpetually flit about in all directions, a phenomenon referred to as Brownian motion. For example, proteins within our cells and pigment particles inside ink-jet printers wriggle and twitch their way through narrow channels of liquid circumscribed by solid surfaces. Yet, unyielding interfaces alter Brownian motion for adjacent objects in liquid—and scientists have not been able to reach a consensus on exactly how those particles behave. [...] Brownian motion itself historically presented a puzzle to top scientific minds. Albert Einstein postulated that the twitchy trajectory is entirely random, theorizing that humans would never be able to measure the millions of minute changes in velocity that move microscopic objects. Recently, however, advanced instruments such as optical tweezers allowed researchers to measure those tiny velocity changes and demonstrate that there is a non-random contribution to Brownian motion. In other words, a particle has a memory of the path it has taken. This memory has a strong influence on the particle's future direction—and, interfaces alter the memory of the particle. However, divisions among researchers persisted about the nature of these effects. Physicists study Brownian motion using either experimental measurements or theoretical calculations. Experimental measurements directly observe real-world events but yield "noisy" data because the nearly instantaneous changes in the speed and direction of a floating object occur right at the boundaries of their resolution limits. [...] However, interface effects on Brownian motion occur over the course of many microseconds—imperceptible on a human time scale, but a relative eternity from a molecule's perspective. [Izabela Szlufarska, a professor of materials science and engineering at UW-Madison, and her student Kai Huang] were able to overcome this impediment by using their recently developed theory that enables them to conduct molecular simulations on experimentally relevant time scales. phys.org
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Superconductor Induces Magnetism In Non-Magnetic Gold
Physicists in the UK have shown that a superconductor can transfer a magnetic field from a magnet to a non-magnetic metal without becoming magnetized itself. The surprising effect is not predicted by any prevailing theory of superconductivity and could have important applications in the emerging field of superconducting spintronics. In a conventional superconductor, electrical current is carried by "Cooper pairs" of electrons. The electron spins in a pair point in opposite directions and therefore the pair has zero net spin. The application of a strong magnetic field destroys superconductivity by encouraging both spins to point in the same direction, which tears the Cooper pairs apart. Weak magnetic fields cannot exist within a conventional superconductor, which acts to expel magnetic-field lines. As a result, superconductivity and magnetism are usually seen as mutually exclusive phenomena. [...] What the researchers found surprised them. They found no evidence of a magnetic field inside the superconductor, but they did see a magnetic field in the gold – even though gold is not normally magnetic. In other words, a magnet on one side of a superconductor can induce a magnetic field on the other side of the superconductor – even though there is no field within the superconductor. Furthermore, the researchers found that the induced magnetic field in the gold depended on the relative orientation of the fields in the two magnetic layers on the opposite side of the superconductor. When the two fields were perpendicular, a strong field was induced. When they were parallel, however, the effect was almost zero. physicsworld.com
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