Keyword: stringtheory
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It's time to gaze into our crystal ball and see what the coming year has in store for science. From powerful new rockets and asteroid-sampling spacecraft to groundbreaking particle physics, there's plenty to look forward to in 2018. Aeronautics and space exploration A new tool to find exoplanets In March 2018, NASA will launch its Transiting Exoplanet Survey Satellite (TESS) - a mission to find previously undiscovered exoplanets from the vantage point of low Earth orbit. The space-based telescope is expected to discover thousands of exoplanets over the next several years as it measures the luminosity of more than 200,000...
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Aluminium oxynitride or AlON is a ceramic composed of aluminium, oxygen and nitrogen. It is marketed under the name ALON by Surmet Corporation. AlON is optically transparent (≥80%) in the near-ultraviolet, visible and midwave-infrared regions of the electromagnetic spectrum. It is 4 times harder than fused silica glass, 85% as hard as sapphire, and nearly 15% harder than magnesium aluminate spinel. Since it has a cubic spinel structure, it can be fabricated to transparent windows, plates, domes, rods, tubes and other forms using conventional ceramic powder processing techniques. ALON is the hardest polycrystalline transparent ceramic available commercially. Combination of optical...
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Photo/Illustraion Japanese researchers have developed a light-emitting device that floats like a firefly and could lead to the creation of mid-air displays and other contraptions. The developers include Yoshihiro Kawahara and Makoto Takamiya, both associate professors with the University of Tokyo, and Yasuaki Kakehi, an associate professor with Keio University. The hemispherical device, with an embedded light-emitting diode, measures 4 millimeters across and weighs 16 milligrams. It can levitate and roam in mid-air when ultrasound beams are applied. The researchers reduced its weight by using a custom-made integrated circuit and by drawing on the technology of wireless powering, or remote...
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In new experiments, however, the physicists coaxed individual photons to cozy up to each other and link, similar to the way individual atoms stick together in molecules. The photon dance happens in a lab at MIT where the physicists run table-top experiments with lasers. Cantu, his colleague Aditya Venkatramani, a Ph.D. candidate in atomic physics at Harvard University, and their collaborators start by creating a cloud of chilled rubidium atoms. Rubidium is an alkali metal so it typically looks like a silver-white solid. But vaporizing rubidium with a laser and keeping it ultracold creates a cloud the researchers contain in...
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The most massive galaxies in our neighbourhood formed their stars billions of years ago, early in the history of the universe. At the present day, they produce very few new stars. Astronomers have long believed that is because they contain very little gas – a key ingredient necessary to produce stars. But our new study, published in Nature Astronomy, is now challenging this long held view. Through probing the extreme environments of faraway massive galaxies, we can learn not only about their evolution and the history of the universe, but most importantly about the fundamental processes regulating the formation of...
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[T]he study of GRBs have been complicated by two major issues. On the one hand, GRBs are very short lived, lasting for only seconds at a time. Second, all detected events have occurred in distant galaxies, some of which were billions of light-years away. Nevertheless, there are a few theories as to what could account for them, ranging from the formation of black holes and collisions between neutron stars to extra-terrestrial communications. ... With the assistance of their collaborators in the US, France, the UK and Sweden, the team from Queen’s University Belfast relied on the Gemini laser, located at...
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These remaining cores of dead stars can only get so massive before they become black holes. _______________________________________________________________________________________________________________________________________ The subtle difference between when a massive dying star compresses into a core and when it collapses entirely may have been found. In a study published in Astrophysical Journal Letters, researchers at the Goethe University in Frankfurt say they’ve found the dividing line between compact objects called neutron stars and black holes. When a massive star reaches the end of its life, it goes out with an immense bang called a supernova. From there, one of two known things Can happen: it either...
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Observations of a trio of dead stars have confirmed that a foundation of Einstein’s gravitational theory holds even for ultradense objects with strong gravitational fields. The complex orbital dance of the three former stars conforms to a rule known as the strong equivalence principle, researchers reported January 10 at a meeting of the American Astronomical Society. That agreement limits theories that predict Einstein’s theory, general relativity, should fail at some level. According to general relativity, an object’s composition has no impact on how gravity pulls on it: Earth’s gravity accelerates a sphere of iron at the same rate as a...
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[T]ime has often been considered as the fourth dimension of space, with three spatial dimensions where one can go up or down, left or right, or forward or backward. But two new papers published in the journal Nature suggest that there might be a fourth spatial dimension, one that could possibly suggest previously undiscovered directions of motion. As detailed in a report from Gizmodo, two separate teams of researchers created their own two-dimensional setups, with one team using ultra-cold atoms and the other one working with waves of light. While the studies produced varying results, the findings complemented each other,...
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A laser-driven technique for creating fusion that dispenses with the need for radioactive fuel elements and leaves no toxic radioactive waste is now within reach, say researchers. Dramatic advances in powerful, high-intensity lasers are making it viable for scientists to pursue what was once thought impossible: creating fusion energy based on hydrogen-boron reactions. And an Australian physicist is in the lead, armed with a patented design and working with international collaborators on the remaining scientific challenges. In a paper in the scientific journal Laser and Particle Beams today, lead author Heinrich Hora from the University of New South Wales in...
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We're about to see — for the very first time — the event horizon of a black hole, proving beyond any last vestige of doubt that Einstein’s interstellar monsters are real. And here’s what it will look like.
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Up for Grabs In Science, When 'Anything Goes,' Everything Goesby Denyse O'Leary Family values activist Austin Ruse's new book, Fake Science: Exposing the Left's Skewed Statistics, Fuzzy Facts, and Dodgy Data (Regnery, 2017), offers a look at a world growing increasingly hostile to evidence-based reasoning. We have not discovered better reasoning methods; rather, many people seem to have decided that reasoning is not relevant to our life together, and perhaps not relevant to the life of the mind generally. Ruse begins his book with a note about polls. Opinion pollsters claim that their work is a scientific enterprise. But in...
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Black holes are famous for their muscle: an intense gravitational pull known to gobble up entire stars and launch streams of matter into space at almost the speed of light. It turns out the reality may not live up to the hype. In a paper published today in the journal Science, University of Florida scientists have discovered these tears in the fabric of the universe have significantly weaker magnetic fields than previously thought. A 40-mile-wide black hole 8,000 light years from Earth named V404 Cygni yielded the first precise measurements of the magnetic field that surrounds the deepest wells of...
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Japanese netizens help scan lightning for gamma rays Japan -- A storm system approaches: the sky darkens, and the low rumble of thunder echoes from the horizon. Then without warning... Flash! Crash! -- lightning has struck. This scene, while familiar to anyone and repeated constantly across the planet, is not without a feeling of mystery. But now that mystery has deepened, with the discovery that lightning can result in matter-antimatter annihilation. In a collaborative study appearing in Nature, researchers from Japan describe how gamma rays from lightning react with the air to produce radioisotopes and even positrons -- the antimatter...
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The finding keeps open the possibility that the particles come from dark matter New observations of the whirling cores of dead stars have deepened the mystery behind a glut of antimatter particles raining down on Earth from space. The particles are antielectrons, also known as positrons, and could be a sign of dark matter — the exotic and unidentified culprit that makes up the bulk of the universe’s mass. But more mundane explanations are also plausible: Positrons might be spewed from nearby pulsars, the spinning remnants of exploded stars, for example. But researchers with the High-Altitude Water Cherenkov Observatory, or...
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The Milky Way, just like every galaxy in the cosmos, moves. While everything in the universe is constantly moving because the universe itself is expanding, since the 1970s astronomers have known of an additional motion, called peculiar velocity. This is a different sort of flow that we seem to be caught in. The Local Group of galaxies — a collection that includes the Milky Way, Andromeda and a few dozen smaller galactic companions — moves at about 600 kilometers per second with respect to the leftover radiation from the Big Bang. Over the past few decades, astronomers have tallied up...
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WASHINGTON – Top scientists in Israel are on the verge of a revolutionary breakthrough, creating a cloak that can render a person invisible. In their real-world quest for invisibility, scientists at Ben-Gurion University have developed a device that scatters light away from an object so it cannot be detected, making the object invisible to the eye. Physicists developed the method for concealing objects based on the study of “metamaterials,” which focuses on exploiting and controlling light by examining how it interacts with objects. Those arrays of minuscule components bend, scatter, transmit or otherwise shape electromagnetic radiation in ways that no...
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The recent finding, detailed in the journal Science today (Nov. 17), concerns positrons, the antimatter complements of electrons. High-energy particles, usually protons, traveling across the galaxy can create pairs of positrons and electrons when they interact with dust and gas in space, study co-author Hao Zhou, at Los Alamos National Lab, told Space.com. In 2008, the space-based PAMELA detector measured unexpectedly high numbers of earthbound positrons. This was about 10 times what they were expecting to see, according to Zhou. ... Zhou's team made detailed measurements of the gamma-rays coming from the direction of two nearby pulsars — Geminga and its companion...
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Bit by qubit, scientists are edging closer to the realm where quantum computers will reign supreme.IBM is now testing a prototype quantum processor with 50 quantum bits, or qubits, the company announced November 10. That’s around the number needed to meet a sought-after milestone: demonstrating that quantum computers can perform specific tasks that are beyond the reach of traditional computers. Unlike standard bits, which represent either 0 or 1, qubits can indicate a combination of the two, using what’s called a quantum superposition. This property allows quantum computers to perform certain kinds of calculations more quickly. But because quantum bits...
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Voevodsky’s friends remember him as constitutionally unable to compromise on the truth — a quality that led him to produce some of the most important mathematics of the 20th century. Vladimir Voevodsky at the Institute for Advanced Study in 2016. In math as in life, Vladimir Voevodsky played by his own rules. Voevodsky, a Russian-born mathematical prodigy, produced a string of daring insights in the 1990s that revolutionized one of the central fields of mathematics and established him at the pinnacle of his profession. His work continues to reverberate today. On Sept. 30, Voevodsky died in Princeton, New Jersey, at...
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