Keyword: stringtheory
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Let's talk about dark energy. We've known for about 20 years that the expansion of our universe is accelerating; every day, our cosmos grows bigger and bigger, doing so faster and faster. It's a subtle effect, and it takes extensive and deep cosmological surveys and studies for scientists to notice it. But multiple independent lines of evidence all point to the same conclusion: accelerating expansion. Astronomers quickly cooked up a cool name for that accelerated expansion: dark energy. But now we’re left with the much harder job of finding a culprit — what's causing it? A universal mistake We use...
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An amazing new Nasa image captures the youngest pulsar ever found by scientists. The pulsar - an ultra-dense chunk of a star leftover from its explosive death into a supernova - sits just 19,000 light years from Earth. It provides our best look yet at the early stages of star death, a mysterious and violent process that scientists still don't fully understand. The image was taken using Nasa's Chandra X-ray Observatory, an orbiting telescope that has been out of action for nearly two weeks following a catastrophic gyroscope failure.
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Our best model of particle physics explains only about 5 percent of the universe. The Standard Model is a thing of beauty. It is the most rigorous theory of particle physics, incredibly precise and accurate in its predictions. It mathematically lays out the 17 building blocks of nature: six quarks, six leptons, four force-carrier particles, and the Higgs boson. These are ruled by the electromagnetic, weak and strong forces. “As for the question ‘What are we?’ the Standard Model has the answer,” says Saúl Ramos, a researcher at the National Autonomous University of Mexico (UNAM). “It tells us that every...
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Astronomers have discovered a massive proto-supercluster of galaxies -- bigger than even one million billion Suns. Scientists have called the ancient colossal structure Hyperion, the European Southern Observatory announced Wednesday. It is reported to have appeared just 2.3 billion years after the Big Bang, which took place about 13.7 billion years ago. The cluster's namesake is one of 12 titans born to the gods Gaia and Uranus in Greek mythology.
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[R]esearchers at the Max Planck Institute for the Structure and Dynamics of Matter are reporting "ultrabright" electron sources with sufficient brightness to literally light up atomic motions in real time—at a time scale of 100 femtoseconds, making these sources particularly relevant to chemistry because atomic motions occur in that window of time. After seeing the first atomic movies of phase transitions in bulk thin films using high-energy (100 kilovolt) electron bunches, the researchers wondered if they could achieve atomic resolution of surface reactions—occurring within the first few monolayers of materials—to gain a better understanding of surface catalysis. So they devised...
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Becoming a popular topic of study only within the past five years, superionic crystals are a cross between a liquid and a solid. While some of their molecular components retain a rigid crystalline structure, others become liquid-like above a certain temperature, and are able to flow through the solid scaffold. "When CuCrSe2 is heated above 190 degrees Fahrenheit, its copper ions fly around inside the layers of chromium and selenium about as fast as liquid water molecules move,"
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-snip- Alessandro Strumia, the physicist in question and a professor at Pisa University in Italy, gave his presentation to a crowd at the European Organization for Nuclear Research (CERN), one of the word's most important nuclear physics organizations. The topic of the day was gender in physics, and the crowd was mostly composed of women, according to The Guardian. Over the course of several slides of his presentation, which are available online, Strumia laid out an IQ-based argument for disparities between men and women in physics. "Physics graduates have top IQ," he wrote. "It's needed." He pointed to a study that...
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Columbia Engineering researchers have created the first flat lens capable of correctly focusing a large range of colors of any polarization to the same focal spot without the need for any additional elements. Only a micron thick, their revolutionary "flat" lens is much thinner than a sheet of paper and offers performance comparable to top-of-the-line compound lens systems. The findings of the team, led by Nanfang Yu, associate professor of applied physics , are outlined in a new study, published today by Light: Science & Applications. A conventional lens works by routing all the light falling upon it through different...
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The newly-discovered particles, named Σb(6097)+ and Σb(6097)-, are predicted by the quark model, and belong to the same family of particles as the protons that the Large Hadron Collider (LHC) accelerates and collides: baryons, which are made up of three quarks. But the type of quarks they contain are different: whereas protons contain two up quarks and one down quark, the new particles are bottom baryons composed of one bottom quark and two up quarks or one bottom quark and two down quarks respectively.The LHCb researchers found these particles using the classic particle-hunting technique of looking for an excess of...
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A senior scientist has given what has been described as a "highly offensive" presentation about the role of women in physics, the BBC has learned. At a workshop organised by Cern, Prof Alessandro Strumia of Pisa University said that "physics was invented and built by men, it's not by invitation". He said male scientists were being discriminated against because of ideology rather than merit. He was speaking at a workshop in Geneva on gender and high energy physics. Prof Strumia has since defended his comments, saying he was only presenting the facts . . .
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"Maybe a black hole could form, and then suck in everything around it," he wrote. "The second scary possibility is that the quarks would reassemble themselves into compressed objects called strangelets." "That in itself would be harmless. However under some hypotheses a strangelet could, by contagion, convert anything else it encounters into a new form of matter, transforming the entire earth in a hyperdense sphere about one hundred meters across." As if this wasn't bad enough, the atom smasher might even be capable of destroying space itself. "Some have speculated that the concentrated energy created when particles crash together could...
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A glob of material the size of Earth is getting sucked into a black hole at nearly one-third the speed of light, a new study reports. The speed of light in a vacuum is 186,282 miles (299,792 kilometers) per second, and, according to Einstein's theory of special relativity, that's the top speed for anything traveling in our universe. So, something zipping at a third the speed of light is moving nearly 56,000 miles (90,000 km) per second — fast enough to circle Earth twice in that brief time. The newly observed infall event occurred in the galaxy PG211+143, which is...
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In this mini world, the concepts of "before" and "after" dissolve, such that two events can both precede and succeed each other. In other words, event A can occur before event B, and event B can occur before event A... This idea, called a "quantum switch," was first proposed in 2009 by another team and has since been explored both theoretically and experimentally. Previous experiments showed event A could both precede and succeed event B, but the research couldn't say that these two scenarios were happening at the same place, said Cyril Branciard, co-author of this new study and a...
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Physicists from the Institute for Solid State Physics at the University of Tokyo, Japan, have recorded the largest magnetic field ever generated indoors — a whopping 1,200 T (tesla)“Magnetic fields are one of the fundamental properties of a physical environment,” said lead author Dr. Daisuke Nakamura and colleagues.“They can be controlled with high precision and interact directly with electronic orbitals and spins; this makes them indispensable for research in areas of solid state physics such as magnetic materials, superconductors, semiconductors, strongly correlated electron materials, and other nanomaterials.”The researchers generated ultrahigh magnetic fields using the electromagnetic flux-compression (EMFC) technique.“We developed a...
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Spacecraft and satellites could in future be launched into space without the need for fuel, thanks to a revolutionary new theory. Dr Mike McCulloch, from the University of Plymouth, first put forward the idea of quantised inertia (QI) – through which he believes light can be converted into thrust – in 2007. He has now received $1.3million from the United States Defense Advanced Research Projects Agency (DARPA) for a four-year study which aims to make the concept a reality. The QI theory predicts that objects can be pushed by differences in the intensity of so-called Unruh radiation in space, similar...
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Radio observations using a combination of NSF’s Very Long Baseline Array, the Karl G. Jansky Very Large Array and the Robert C. Byrd Green Bank Telescope have revealed that a fast-moving jet of particles broke out into interstellar space after a pair of neutron stars merged in NGC 4993, a lenticular galaxy approximately 130 million light-years from Earth.-snip- Called GW170817, the merger of two neutron stars sent gravitational waves rippling through space. It was the first event ever to be detected both by gravitational waves and electromagnetic waves, including gamma rays, X-rays, visible light, and radio waves.The aftermath of the...
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Physicists have revealed that just seven quantum particles can behave as if they were in a crowd of billions. At larger scales, matter goes through changes, called phase transitions, in which (for example) water turns into a solid (ice) or a vapor (steam). Scientists were used to seeing this behavior in large masses of molecules, but never in such a tiny cluster. In a new study, detailed today (Sept. 10) in the journal Nature Physics, researchers witnessed these phase transitions in systems made up of just seven light particles, or photons, which took on an exotic physical state known as a Bose-Einstein condensate (BEC). That's...
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Scientists have reached a “milestone” in a technique of semi-artificial photosynthesis that could eventually create an “unlimited source of renewable energy,” according to a new study. Artificial photosynthesis has been around for decades, but scientists haven’t been able to develop it on a scale large enough to support an industrial level, or that could operate without the use of expensive or polluting devices. Semi-artificial photosynthesis, a relatively new field of study, aims to address those concerns by combining manmade technologies with biological processes in order to mimic nature’s method of splitting water into oxygen and hydrogen. In the latest study,...
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That's a big deal, because it could lead to much smaller and cheaper particle accelerators than the ones we currently rely on. Right now, if you want to install a Large Hadron Collider (LHC) particle accelerator in your back garden, you need a concrete tunnel about 27 kilometres (nearly 17 miles) long and US$5 billion in spare change. But this new experiment uses something known as plasma wakefield acceleration – and it takes up just 10 metres or 33 feet of space. The team behind the Advanced Proton Driven Plasma Wakefield Acceleration Experiment (AWAKE) at CERN in Geneva has been...
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The University of Queensland and the NÉEL Institute has shown that, as far as quantum physics is concerned, the chicken and the egg can both come first. Dr Jacqui Romero from the ARC Centre of Excellence for Engineered Quantum Systems said that in quantum physics, cause-and-effect is not always as straightforward as one event causing another. "The weirdness of quantum mechanics means that events can happen without a set order," she said. "Take the example of your daily trip to work, where you travel partly by bus and partly by train. "Normally, you would take the bus then the train,...
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