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
How A Black Hole Flares
Black holes are paradoxically some of the brightest objects in the universe. It’s not the black holes themselves that are bright; it’s their entourages. Surrounding these spacetime warps are glowing disks of hot gas, which can feed blazing jets and flares. Astronomers regularly watch black holes flare, but they’re not actually sure why flares happen. New X-ray observations suggest that these brilliant surges are a sort of physics-engendered optical effect, created by changes in a mysterious structure called the corona. The corona is a haze of high-energy electrons that hovers over the black hole and its accretion disk. The electrons whiz around with so much energy that when they collide with ultraviolet photons flying away from the disk, they give a mighty kick that turns those photons into X-rays. These X-rays in turn reflect back off the accretion disk, carrying away spectral fingerprints from the disk that reveal things like how fast the black hole is spinning. [...] The team thinks that, before a flare, the corona spreads out across the disk’s surface. Then it gathers itself together, like a cat preparing to spring — except instead of a ball of fur and nails, it contracts into a vertical, jetlike structure. This compact corona then launches off the disk at roughly 20% the speed of light. Here’s where the modern physics kicks in: when an object moves at fair fractions of the speed of light, it beams more of its radiation in the direction it’s moving — which, in this case, is away from the disk. The effect is called relativistic beaming. So although the corona is still effectively blazing in X-rays, most of those X-rays aren’t pointed at the disk and so aren’t reflecting off it. Plus, since the corona is now farther away from the black hole, more of the photons can escape the black hole’s gravity and reach us. The flare ends when the jetlike corona collapses back to the disk. skyandtelescope
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What the Flux? No Sign of Aliens Around Strange, Dimming Star
If alien civilizations are broadcasting from around a strangely behaving star, they aren't chatting loud enough for humans to hear them from Earth, new observations show. The star KIC 8462852 garnered popular attention in October, when scientists announced that it showed evidence of periodically dimming by 20 percent or more, which some people theorized could be caused by the shadow of an alien megastructure. However, observations of KIC 8462852 by the Search for Extraterrestrial Intelligence (SETI) have picked up no radio signals that could indicate extraterrestrial chatter, SETI scientists say. [...] Several natural explanations were proposed, including the presence of a swarm of comets orbiting the star, which lies about 1,400 light-years from Earth. Far more popular, however, was the idea that the Kepler-studied star hosts a swarm of alien megastructures in orbit, built by technologically advanced civilizations. With this possibility in mind, SETI turned the Allen Telescope Array on the star, studying it for more than two weeks. The instrument examined the star for two types of radio signals. Narrowband signals, which make up most SETI searches, are considered plausible for advanced societies to use as a "hailing signal" to announce their presence to other civilizations. Broadband signals might come from spacecraft servicing any alien projects around the star, and could leak from spacecraft propelled by intense microwave beams. [...] But SETI announced in a statement yesterday (Nov. 5) that there was "no clear evidence for either type of signal." The search rules out omnidirectional transmitters that use a minimum amount of energy to broadcast their signal — specifically, according to SETI, this minimum is approximately 100 times the total amount of energy currently used on Earth (terrestrially) for the narrowband signals, and those 10 million times higher than that for broadband emissions. space
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Biology
Elephants May Use Trunks Like 'Leaf Blowers' To Obtain Inaccessible Food
Two captive elephants blast air through their trunks to grasp hard-to-reach food, suggests an initial study published today in Springer's journal Animal Cognition. This behaviour, studied in a zoo population of Asian elephants (Elephas maximus), is altered according to the distance to the food, which may indicate advanced mental ability and awareness of their physical environment. [...] To test this theory, the team of researchers digitally mapped out a grid in a ditch in the elephants' enclosure, placed food in various locations on the 'virtual' grid, and filmed the elephants trying to reach it. They used five different types of food: apple, bamboo, hay, fallen leaves and potatoes. The researchers recorded the elephants' behaviour over 32 days, spilt into 128 trials; a trial began when it was audible that the elephants had started blowing and finished when they grasped the food or gave up. They then analysed the frequency and duration of blowing, the position and shape of the elephants' trunks, and their success and skill by tracking the movement of food across the grid. Their results reveal that on average it took three blasts of air for the elephants to reach inaccessible food and they were less likely to exhibit this behaviour if food was nearby. Mineko, the dominant female, was more proficient, particularly when it came to adjusting the position of her trunk to target the air at a specific point on the food to push it in the right direction. Lead author, Kaori Mizuno, said: "By blowing air through their trunks to obtain inaccessible food, the elephants appear to exhibit an advanced understanding of their physical environment. Their skills to manipulate air might be related to those elephants commonly use, such as blowing for self-comfort and acoustic communication" The authors discuss whether, by using it in this manner, an elephant's breath could be defined as a 'tool', like the sticks used by chimpanzee to catch ants. They conclude that their study offers an opportunity to critically rethink the definition of a 'tool', focusing on the psychological process behind problem-solving behaviour, rather than the use of a physical object. biologynews
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Francis’ Woolly Horseshoe Bat: New Species Of Bat Discovered
The new species belongs to the bat genus Rhinolophus, the single extant genus in the family Rhinolophidae. Members of this genus typically have a horseshoe-shaped, leaf-like structure on their nose, earning them the common name ‘horseshoe bats.’ The bats use this structure to focus the sound of their echolocation calls, which are used for navigation and finding food, according to an international team of scientists, including Dr Roberto Portela Miguez from the Natural History Museum, London, UK. The name of the newly discovered Rhinolophus species – the Francis’ woolly horseshoe bat (Rhinolophus francisi) – honors Dr Charles M. Francis, a scientist who collected the type specimen of the new species in Malaysia in 1983.
“The new species is currently known from only six records; with two records in Sabah, Malaysian Borneo; three in Indonesian Borneo (Kalimantan) and a single record in Thailand,” Dr Portela Miguez and his colleagues said. “The species may be distributed more widely in these regions, but has been rarely captured despite extensive surveys. Genetic data also suggest that this species is likely to occur in Vietnam, although this needs to be confirmed.”
sci-news
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Chemistry
Eye Drops Show Promise Treating Cataracts And Even Reversing Damage
A molecule that can bind and re-solubilise mis-folded proteins in the eye has been identified by researchers in the US. The molecule – a sterol – shows potential as a non-surgical treatment for cataracts – eye drops containing it were able to partially reverse cataracts in mice and restore some transparency in isolated human lenses. Currently, people who develop cataracts must have an operation to remove them to restore their sight. While this is relatively straightforward in the developed world, Jason Gestwicki from University of California at San Francisco (UCSF), who led the research, says: ‘There are about 100 million people in the world that are currently blind from cataracts because of lack of access to the surgical procedure. A topical treatment with good shelf life that requires minimal training is really what is needed.’ Cataracts are caused by damaged crystallin proteins in the eye lens. These proteins start off soluble and transparent, but they are never replaced and can become mis-folded over time forming opaque, insoluble clumps that are highly stable. ‘If we can find a small molecule that binds the soluble, natural fold of the crystallin proteins – the free energy of that interaction will make that the more stable form … and we’ll basically turn back the clock on the ageing of that protein,’ explains Gestwicki. rsc
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Amino Acids Could Help Determine Sex Of Fingerprint Originators
For more than a century, forensic scientists have scoured crime scenes for fingerprints to help identify who was present during a crime. New research goes beyond the swirls and whorls of fingerprint patterns to demonstrate that the amino acids in the sweat within fingerprints can identify the sex of the person who made them Researchers have used analytical chemistry before to try to glean information about the makers of fingerprints by measuring prints’ chemical composition in the lab. But Jan Halámek, an assistant professor of chemistry at the University at Albany, SUNY, wants to devise a portable, easy-to-read testing method that could determine attributes such as the sex, age, or ethnic origin of someone who left fingerprints behind. As a starting point, he tackled sex determination, based on hormone differences between men and women that cause women to have higher levels, and a slightly different distribution, of amino acids in their sweat, which is deposited in fingerprints along with lipids and other chemical traces. Amino acid levels in the sweat of females are about twice as high as in males, Halámek says. First the team devised a method to extract the amino acids from a fingerprint by transferring it onto a polyethylene film, placing a drop of diluted hydrochloric acid onto the print, and then heating it. The water-soluble amino acids migrate into the solution, leaving the lipids behind. To measure the levels of extracted amino acids, the team devised a colorimetric test involving two enzymes. L-Amino acid oxidase produces hydrogen peroxide from the amino acids, and then horseradish peroxidase catalyzes a reaction between hydrogen peroxide and a dye to make a colored compound that can be measured with simple light spectroscopy. Halámek’s group first tested their procedure on mimicked fingerprint samples—50 amino acid mixtures randomly generated to represent compositions characteristic of male and female fingerprints—and found that the test had a 99% chance of correctly classifying a given mixture as male or female. Then the research team tested the method on real fingerprints. They collected three male and three female fingerprints on polyethylene film and found that they could successfully distinguish between the two sexes in a blind test. He and his lab members also successfully tested the method on real fingerprints left on five different surfaces, including a doorknob and a desktop. Halámek has since transferred the reaction components onto paper to make a quick, easy-to-read test similar to pregnancy strips or glucometers, which can be used and understood by people without scientific backgrounds, he said. acs
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Earth Science
Coal Not So 'Amazing', Public Say, As Mining Industry Advertising Backfires
A major advertising campaign that claimed coal was “amazing” and had “endless possibilities” appears to have proved counter-productive, a new poll suggests. The net approval rating of coal fell by 9% after Australia’s mining industry ran the “Little Black Rock” campaign, which began in September across TV, radio, press and online, and featured a close-up of a lump of glistening coal. The ad claimed coal added $40bn a year to Australia’s economy and “can now reduce its emissions by up to 40%”. The tagline was: “Isn’t it amazing what this little black rock can do?” Before the ads were aired the net approval for coal was -18% but after they aired it had dropped to -27%, a net change of -9%. [...]
“The coal industry has been running this aggressive advertising campaign but they’ve been doing so in the face of an ongoing sea of information, public releases and news stories about the decline of the industry,” Sheikh told Guardian Australia. “They’re trying to tell a positive story about coal when the numbers tell a very different story. And what it shows is that people see through it when they read the newspaper, when they talk to friends and family; they understand the story that the industry is not going to be part of Australia’s future.”
theguardian
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Nuclear Waste Site Near St Louis Threatened By Landfill Fire
Imagine you are a parent, and that out of the blue, you get a letter from your child's school telling you not to worry — that they're ready to evacuate or shelter in place if an underground fire at a nearby landfill reaches radioactive waste on the same property. That's pretty much what happened recently in suburban St. Louis. Landfill fires are pretty common. But this one is different: It's only about a thousand feet away from nearly 9,000 tons of nuclear waste — and there's no barrier in between. Hundreds of people packed a recent community meeting about the landfills, located in Bridgeton, Mo. [...] Many of the people at the meeting didn't know of the landfills' existence, even though the fire started five years ago, and the radioactive waste was dumped back in the early 1970s. [...] Flares at the Bridgeton Landfill outside St. Louis burn off noxious fumes, including those generated by an underground fire that's been burning since 2010. The "fire" is really a high-temperature chemical reaction that consumes the waste below the landfill's surface. enn
Physics
New Discovery Could Enable Portable Particle Accelerators
Conventional particle accelerators are typically big machines that occupy a lot of space. Even at more modest energies, such as that used for cancer therapy and medical imaging, accelerators need large rooms to accommodate the required hardware, power supplies and radiation shielding. A new discovery by physicists at the University of Maryland could hold the key to the construction of inexpensive, broadly useful, and portable particle accelerators in the very near future. The team has accelerated electron beams to nearly the speed of light using record-low laser energies, thus relieving a major engineering bottleneck in the development of compact particle accelerators. The work appears in the November 6, 2015 issue of the journal Physical Review Letters. "We have accelerated high-charge electron beams to more than 10 million electron volts using only millijoules of laser pulse energy. This is the energy consumed by a typical household lightbulb in one-thousandth of a second." said Howard Milchberg, professor of Physics and Electrical and Computer Engineering at UMD and senior author of the study. "Because the laser energy requirement is so low, our result opens the way for laser-driven particle accelerators that can be moved around on a cart." "As an unexpected bonus, the accelerator generates an intense flash of optical light so short that we believe it represents only one-half of a wavelength cycle," Milchberg added. These ultrashort light flashes could lead to the development of optical strobe lights that can capture the motion of electrons as they swarm across their atomic orbits—a potentially important development for materials science and nanotechnology. phys.org
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Why’s There Chatter In My Himalayan Singing Bowl?
A Himalayan singing bowl operates much in the same way as a wine glass -- slide your fingertip, or a wooden stick called a puja, around its rim to hear its soothing tones. The bowls, which originated in the Tibetan mountain region and are made of metal alloys, have been used for meditation and worship since around 500 BCE, but have found recently new audiences in contemporary music. While the complex stick-slip motions responsible for "chatter," or rapid knocking sounds, have been extensively studied in other instruments, few studies have investigated this action in the Himalayan singing bowl. [...] "As the puja moves around the rim of the bowl, it switches very quickly between sticking to and slipping on the metal, which is called 'stick-slip motion,'" said Chloe L. Keefer, one of the researchers and an undergraduate at Rollins College, Florida. This motion is responsible for producing sounds in a wide variety of musical instruments, including the violin and cello, and many additional non-instrument vibrational processes. Using a laser Doppler vibrometer, a scientific instrument for making non-contact measurements of the vibrations of a surface, Keefer's team measured vibrations at several points on the inner rim of the bowl near where the puja contacted the bowl.
"The puja's motion excites the vibration of the singing bowl, causing a unique deflection shape," Keefer explained. Their experiments showed that the puja forces a point of zero vibration called "a node" on the bowl, which lies in the vicinity of the contact point of the puja. "The interesting part of the puja's motion is that people would expect the puja to lie on the node of the bowl's vibratory motion, but in fact it doesn't," Keefer said.
Rather, this node lies within two millimeters of the puja, she explained. As the puja rotates around the rim, the node follows behind it, and as the puja rotates faster and faster, the displacement or the vibration amplitude of the rim increases accordingly. When the amplitude of the vibration is large enough, it will briefly knock the puja off the bowl, producing chatter. sciencedaily
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