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
Kuiper Belt Target Picked For New Horizons
NASA's New Horizons team members are still basking in the afterglow of July's historic flyby of Pluto — and still awaiting most of the observations made there. But they're already anticipating the spacecraft's second and likely final encounter in the distant Kuiper Belt. Last week the space agency announced the spacecraft's target. It's 2014 MU69, an object situated 43.3 astronomical units (6.49 billion km) from the Sun. Astronomers know little about 2014 MU69, other than it's an incredibly dim 25.6-magnitude blip. It's not big — assuming a surface that's 20% reflective (just a guess), astronomers estimate its diameter to be about 45 km (30 miles) across. That's roughly 10 times the size of a typical comet. But New Horizons isn't zeroing in on this object based on its size or any other physical characteristic. Instead, it's all about location. The spacecraft should be able to reach 2014 MU69 in a reasonable amount of time and still have comfortable fuel reserves for its maneuvering engines once it gets there. Plans call for a series of four trajectory corrections in late October and early November to set course for a rendezvous on January 1, 2019. skyandtelescope
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Tatooine-Like Planets With 2 Suns Need Perfect Ingredients To Form
Astronomers have long struggled with how young planets form around pairs of stars without destroying themselves, but new research suggests it can be done with the perfect setup: a massive, slightly elongated disk of debris from the star. Planets forming around a star with another stellar neighbor nearby must somehow overcome the gravity of the second star during the formation process. A new view of the process suggests that the material in two-sun systems similar to Tatooine in "Star Wars" can indeed overcome the star's destructive pull and form planets, even very small ones — if the planet-forming material around the star is sufficiently massive and the disk of material is slightly stretched. "It may seem surprising given the disk is less massive, but if you're moving far from the central star a lot of the disk material is around you, while the central binary is concentrated toward the center," Kedron Silsbee, a graduate student at Princeton University, said at the recent Emerging Researchers in Exoplanet Science Symposium at Pennsylvania State University. Working with Roman Rafikov, also of Princeton, Silsbee modeled planetary formation in close binaries. "It turns out the disk can actually be the dominant component," Silsbee said. space.com
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Biology
A Marine Creature's Magic Trick Explained
Tiny ocean creatures known as sea sapphires perform a sort of magic trick as they swim: One second they appear in splendid iridescent shades of blue, purple or green, and the next they may turn invisible (at least the blue ones turn completely transparent). How do they get their bright colors and what enables them to "disappear?" New research at the Weizmann Institute has solved the mystery of these colorful, vanishing creatures, which are known scientifically as Sapphirinidae. The findings, which recently appeared in the Journal of the American Chemical Society, could inspire the development of new optical technologies. Sapphirinidae belong to a subclass of crustaceans called copepods; and they live in fresh or salt water. These animals are barely visible to the human eye, ranging from around one to several millimeters in length. It is the male Sapphirinidae that display striking, iridescent colors, whereas the female is transparent. Scientists think that their unique magic trick could help Sapphirinidae escape predators when necessary, but still display their flashy colors when a female of the species - or possibly another male - is nearby. [...] These colors are due to iridescence - the result of light reflecting off periodic (repeating) structures. These multilayer reflectors - a type of structure known to scientists as a photonic crystal - are composed of thin, transparent crystals of guanine. Guanine is more generally known as one of the nucleic acid bases found in DNA. The research group found that the guanine plates in Sapphirinidae are stacked in incredibly precise periodic arrays. What gives each species its unique color? Their analysis revealed that the main factor determining whether an animal will be yellow, blue or purple is the spacing between plates, which is controlled by the thin layer of cellular material separating them. The researchers also showed how this complex arrangement of plates enables some Sapphirinidae to disappear from sight: When certain species of male Sapphirinidae rotate their backs to the light at a 45-degree angle as they perform a spiral swimming maneuver, the wavelength of the reflected light is shifted out of the visible light range and into the invisible ultraviolet. In contrast, light hitting straight-on returns the beautiful blue color. In the ocean's light, which comes from above, the tiny creature can control its visibility, from neon to none, just by adjusting its rudder. biologynews.net
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Microscopic Animals Inspire Glass Research
The creatures, which go by the more formal name of tardigrades, have a remarkable ability to withstand extreme environments of hot and cold, and even the vacuum of space. When de Pablo read about what happens when scientists dry out tardigrades, then revive them with water years later, his interest was piqued. "When you remove the water, they very quickly coat themselves in large amounts of glassy molecules," says de Pablo, the Liew Family Professor in Molecular Engineering at the University of Chicago. "That's how they stay in this state of suspended animation." His passion to understand how glass forms in such exotic settings helped lead de Pablo and his fellow researchers to the unexpected discovery of a new type of glass. [...] "These are intriguing materials. They have the structure of a liquid, and yet they're solids. They're found everywhere, and we still do not understand how this process of turning from a liquid into a solid occurs," says de Pablo. sciencedaily
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Chemistry
Shrinking Hydrogel Reinforces Fabric For Soft Yet Strong Material
For many applications, an ongoing challenge is to develop materials with seemingly contradictory properties. For example, the biomedical field wants materials that are tough, yet soft, wet, flexible and biocompatible – quite a tall order. Many researchers have spotted the potential of hydrogels, which are known for being soft and biocompatible, but limited by their lack of strength. ‘The current interest is to develop hydrogel-based materials that are flexible in bending and stiff in stretching,’ says Jian Ping Gong from the Hokkaido University. Gong’s group want to make synthetic materials with similar properties to biological ligaments – tough with the ability to load-bear, but also soft and bendy. Natural ligaments incorporate collagen fibres within a gel matrix. But mimicking this approach with fibres and hydrogels is not without its challenges: ‘Conventional hydrogels usually have weak adsorption in the solid phase due to extensive swelling in water after preparation,’ explains Gong. In this new study, Gong, together with Alfred Crosby from the University of Massachusetts, US, and their co-workers, modified the fibre-reinforced hydrogel design by combining a tough glass fibre fabric with a polyampholyte hydrogel. They found their formula had a synergistic effect; the mechanical properties of the hydrogel–fabric composite far outperformed the individual components. The fracture energy of the composite is 250,000J/m2 – much higher than the fabric alone (75,000J/m2) or existing fibre-reinforced hydrogels (4,000–30,000J/m2). Hydrogel choice is key. Polyampholyte gels are made from equal amounts of oppositely charged monomers. And unlike typical hydrogels, which swell in water, polyampholyte gels shrink. When making the composite, ionic bonds form between hydrogel monomers to trigger the de-swelling. This action enhances adhesion between the gel and the fibres, anchoring the fibres closer together and thus makes the fabric stronger, tougher, and less likely to tear. Importantly, the fabric still retains a high water content. rsc.org
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Self-Healing Spaceship Shielding Could Keep Astronauts Safer
It's a scenario straight out of Hollywood: You're up in a spacecraft, "you've got this capsule around you," and a loose bolt, a piece of space junk, is zooming your way. "And it's going really fast. It's going to very likely pass through your spacecraft and leave both entry and exit holes. So all of a sudden now your atmosphere is rushing out those holes, and you want them sealed right away." That's Timothy Scott, a polymer scientist at the University of Michigan, Ann Arbor. He and his team have devised a potential solution to this space disaster: a material that patches itself up, less than a second after impact. Think of an ice-cream sandwich. "The central part, the ice cream of our sandwich, is a liquid resin." The cookie parts are sheets of thermoplastic. When a projectile—or piece of space junk—punctures the sandwich, it exposes the liquid part to the ship’s oxygen, which causes it to solidify, patching the hole. The researchers tested sheets of the self-healing material at a firing range, filming the results with high-speed video. And indeed, the material worked fine here on Earth—but they say the findings will have to be replicated under pressure conditions like those you'd find in space. scientificamerican
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Earth Science
Fighting Explosives Pollution With Plants
A team from the Centre for Novel Agricultural Products (CNAP) in the University’s Department of Biology has unravelled the mechanism of TNT toxicity in plants raising the possibility of a new approach to explosives remediation technology. TNT has become an extensive global pollutant over the last 100 years and there are mounting concerns over its toxicity to biological systems. [...] TNT has a significant impact on the diversity of soil microbial communities and the establishment of vegetation. The majority of TNT remains in the roots of plants, where it inhibits growth and development. In the U.S. alone it is estimated that some 10 million hectares of military land is contaminated with munitions constituents. But whereas it is possible to ban toxic and polluting chemicals, the huge demand for military explosives means that TNT will continue to be used globally on a massive scale. The researchers discovered that a key plant enzyme -- MDHAR6 -- reacts with TNT, generating reactive superoxide, which is highly damaging to cells. They found that mutant plants lacking the enzyme, previously implicated in protecting plants from stress, in fact have an enhanced TNT tolerance. By targeting this enzyme in relevant plant species, it may be possible to produce TNT resistant plants to revegetate and remediate explosives at contaminated sites such as military ranges and manufacturing waste sites. enn.com
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Nearly Every Seabird On Earth Is Eating Plastic
So much plastic trash is flowing into the oceans that 90 percent of seabirds eat it now and virtually every one will be consuming it by 2050. That finding, revealed in a new study published this week, tracks for the first time how widespread plastics have become inside seabirds around the world. “That was shocking,” says Chris Wilcox, a research scientist with Australia’s Commonwealth Scientific and Industrial Research Organization and lead author of the study. “Essentially, the number of species and number of individuals within species that you find plastic in is going up fairly rapidly by a couple percent every year.” [...] The most disturbing finding, Wilcox says, is the link between the increasing rate of plastics manufacturing and the increasing rate at which the material is saturating seabirds. “Global plastic production doubles every 11 years,” Wilcox says. “So in the next 11 years, we’ll make as much plastic as we’ve made since plastic was invented. Seabirds’ ingestion of plastic is tracking with that.” nationalgeographic
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Physics
Playing The Cosmic Piano
Researchers at CERN are renowned for their musical side-projects. Notable examples include the album released by scientists at the ATLAS detector in 2010, and the “Large hadron rap“, which currently has almost 8 million hits on YouTube. And of course don’t forget the pop-star-turned-physicist Brian Cox who had the UK chart-topping hit “Things can only get better” in the 1990s with his band D:Ream. Following in this musical tradition, a duo of Mexican researchers has invented a “Cosmic Piano” inspired by the technologies used at the ALICE particle detector at the Large Hadron Collider (LHC). The instrument’s inventors Arturo Fernández Téllez and Guillermo Tejeda Muñoz hold positions at CERN and the University of Puebla in Mexico. They hope the device can demonstrate both the science and the art of the work being carried out at particle-physics facilities. Looking a bit like a fancy staircase and sounding a bit like R2-D2 from the Star Wars films, the device is triggered by charged particles. As Fernández explains in [this video], these charged particles are produced when cosmic rays interact with molecules in the Earth’s atmosphere. The particles generate an optical signal within a plastic scintillator, which converts an electric current into beeping sounds and jazzy light pulses. Fernández and Tejeda created the device after the CERN management had put out a call for inventions to be showcased at CERN Open Days in 2013. The Cosmic Piano proved a big hit – several of them have since been sold for around US$2500 and the instrument even made an appearance at the 2014 Montreux Jazz Festival in Switzerland. physicsworld
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The Theory Of Parallel Universes Is Not Just Maths It Is Science That Can Be Tested
The existence of parallel universes may seem like something cooked up by science fiction writers, with little relevance to modern theoretical physics. But the idea that we live in a "multiverse" made up of an infinite number of parallel universes has long been considered a scientific possibility – although it is still a matter of vigorous debate among physicists. The race is now on to find a way to test the theory, including searching the sky for signs of collisions with other universes. It is important to keep in mind that the multiverse view is not actually a theory, it is rather a consequence of our current understanding of theoretical physics. This distinction is crucial. We have not waved our hands and said: "Let there be a multiverse". Instead the idea that the universe is perhaps one of infinitely many is derived from current theories like quantum mechanics and string theory. [...] The String Landscape String theory is one of our most, if not the most promising avenue to be able to unify quantum mechanics and gravity. This is notoriously hard because gravitational force is so difficult to describe on small scales like those of atoms and subatomic particles – which is the science of quantum mechanics. But string theory, which states that all fundamental particles are made up of one-dimensional strings, can describe all known forces of nature at once: gravity, electromagnetism and the nuclear forces. However, for string theory to work mathematically, it requires at least ten physical dimensions. Since we can only observe four dimensions: height, width, depth (all spatial) and time (temporal), the extra dimensions of string theory must therefore be hidden somehow if it is to be correct. To be able to use the theory to explain the physical phenomena we see, these extra dimensions have to be "compactified" by being curled up in such a way that they are too small to be seen. Perhaps for each point in our large four dimensions, there exists six extra indistinguishable directions? A problem, or some would say, a feature, of string theory is that there are many ways of doing this compactification – 10^500 possibilities is one number usually touted about. Each of these compactifications will result in a universe with different physical laws – such as different masses of electrons and different constants of gravity. However there are also vigorous objections to the methodology of compactification, so the issue is not quite settled. [...] Testing The Theory The universes predicted by string theory and inflation live in the same physical space (unlike the many universes of quantum mechanics which live in a mathematical space), they can overlap or collide. Indeed, they inevitably must collide, leaving possible signatures in the cosmic sky which we can try to search for. phys.org
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