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Explanation: What happens when a star gets too close to a black hole? Recent observations from Earth-orbiting observatories of an event dubbed ASASSN-14li, in a distant galactic center, appears to be giving one star's harrowing story. Although angularly unresolved, variations in high energy light indicate that some of the star became shredded and reformed into a disk swirling around the dark abyss. In the hypothesized scenario envisioned, a jet formed on the spin axis of the black hole. The innermost part of the disk, colored white, glows most strongly in X-rays and may drive a periodic wind, shown in blue....

Photonic devices, which use light to transport large amounts of information quickly, have the potential to enhance or even replace the electronic devices that are ubiquitous in our lives today. But before such optical connections can be integrated into telecommunication systems and computers, researchers need to make it easier to manipulate light at the nanoscale. A new on-chip zero-index metamaterial makes this possible, opening the door for technological innovation and research. This new metamaterial was developed in the lab of Eric Mazur at the Harvard John A. Paulson School of Engineering and Applied Sciences (SEAS), and is described in the...

Explanation: What happens when two black holes collide? This extreme scenario likely occurs in the centers of some merging galaxies and multiple star systems. The featured video shows a computer animation of the final stages of such a merger, while highlighting the gravitational lensing effects that would appear on a background starfield. The black regions indicate the event horizons of the dynamic duo, while a surrounding ring of shifting background stars indicates the position of their combined Einstein ring. All background stars not only have images visible outside of this Einstein ring, but also have one or more companion images...

The Universe Never Expands Faster Than the Speed of Light Breaking my radio silence here to get a little nitpick off my chest: the claim that during inflation, the universe “expanded faster than the speed of light.” It’s extraordinarily common, if utterly and hopelessly incorrect. (I just noticed it in this otherwise generally excellent post by Fraser Cain.) A Google search for “inflation superluminal expansion” reveals over 100,000 hits, although happily a few of the first ones are brave attempts to squelch the misconception. I can recommend this nice article by Tamara Davis and Charlie Lineweaver, which tries to address...

Scientists at TU Wien (Vienna) have calculated that the meson f0(1710) could be a very special particle -- the long-sought-after glueball, a particle composed of pure force. The prediction that glueballs exist is one of the most important of the Standard Model of particle physics that has not yet been confirmed experimentally. For decades, scientists have been looking for so-called "glueballs". Now it seems they have been found at last. A glueball is an exotic particle, made up entirely of gluons -- the "sticky" particles that keep nuclear particles together. Glueballs are unstable and can only be detected indirectly, by...

CAMBRIDGE, Mass. (AP) — The Massachusetts Institute of Technology has offered free online courses for the last four years with one major downside: They didn't count toward a degree. That's about to change. In a pilot project announced Wednesday, students will be able to take a semester of free online courses in one of MIT's graduate programs and then, if they pay a "modest fee" of about $1,500 and pass an exam, they will earn a MicroMaster's credential, the school said. The new credential represents half of the university's one-year master's degree program in supply chain management....

White Hole. Credit: universe-review.ca =================================================================================================================== Black holes are created when stars die catastrophically in a supernova. So what in the universe is a white hole? It's imagination day, and we're going to talk about fantasy creatures. Like unicorns, but even rarer. Like leprechauns, but even more fantastical! Today, we're going to talk about white holes. Before we talk about white holes, let's talk about black holes. And before we talk about Black Holes, what's is this thing you have with holes exactly? Black holes are places in the universe where matter and energy are compacted so densely together that their...

Sometimes you have to think outside the box. Faced with some of the universe’s most stubborn mysteries, such as the identity of dark matter, physicists are turning to a technique that employs the weird laws of quantum mechanics: atom interferometry. Atom interferometers allow the study of various physical phenomena by splitting atom waves using a nanograting, such as this one. Composed of silicon nitride, this grating, imaged with a scanning electron microscope, has a period of 100 nm. Image courtesy of Alex Cronin (University of Arizona, Tucson, AZ). This method, which takes advantage of the fact that quantum particles behave...

A Japanese scientist has won this year's Nobel Prize in Physics. Takaaki Kajita proved that neutrinos have mass. The neutrino is an elementary particle consisting of matter. Kajita observed neutrinos at a facility deep underground. He was part of a team that detected that some of the particles change to different types of neutrino. That proved neutrinos have mass. The discoveries were revealed at an international conference in 1998. His work surprised researchers all around the world because it disproved the established theory that neutrinos do not have mass. Kajita is the 24th Nobel Prize winner born in Japan. And...

Could the famed “Big Bang” theory need a revision? A group of theoretical physicists suppose the birth of the universe could have happened after a four-dimensional star collapsed into a black hole and ejected debris. Before getting into their findings, let’s just preface this by saying nobody knows anything for sure. Humans obviously weren’t around at the time the universe began. The standard theory is that the universe grew from an infinitely dense point or singularity, but who knows what was there before? “For all physicists know, dragons could have come flying out of the singularity,” stated Niayesh Afshordi, an...

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...

If you visit the Paris Observatory on the left bank of the Seine, you'll see a plaque on its wall announcing that the speed of light was first measured there in 1676. The odd thing is, this result came about unintentionally. Ole Romer, a Dane who was working as an assistant to the Italian astronomer Giovanni Domenico Cassini, was trying to account for certain discrepancies in eclipses of one of the moons of Jupiter. Romer and Cassini discussed the possibility that light has a finite speed (it had typically been thought to move instantaneously). Eventually, following some rough calculations, Romer...

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,...

Are We Living In A Black Hole? // / Here’s an idea, what if the universe and everything we see around us is actually inside a black hole?Whenever I’m asked this question, what folks typically have in mind is that the universe began as an infinitely dense point, just like the singularity of a black hole, and because of cosmic expansion there’s a limit to how far we can observe, so maybe that’s like the event horizon. While it’s an interesting idea, things aren’t quite so simple.To begin with, the universe did not begin with an explosion from a...

For years nuclear scientists have talked about a revival of molten salt reactors, which are powered by a liquid fuel rather than solid fuel rods, that will help spark the long-awaited “nuclear renaissance.” Recent developments indicate that this alternative nuclear power technology is finally making progress toward commercialization. A consortium of research institutes and universities working under the aegis of the European Commission, including the Technology University of Delft (TU Delft), in the Netherlands, France’s National Center for Scientific Research, and the Commission’s Joint Research Center, in Brussels, in August embarked on a four-year research program designed to demonstrate the...

The matter, known as a quark-gluon plasma (or QGP), is predicted to exist when temperatures and densities are so extreme that regular matter cannot exist. Instead, a “perfect liquid” exists for a short time before it cools and condenses into the regular stuff that forms the building blocks of matter. Although physicists have announced the detection of this exotic state of matter before, new results from the Relativistic Heavy Ion Collider (RHIC) at the U.S. Department of Energy’s (DOE) Brookhaven National Laboratory, in Upton, New York, appear to show the tiniest droplets of quark-gluon plasma appear, in a specific pattern,...

ATLAS and CMS experiments shed light on Higgs properties 01 Sep 2015 Results of the analyses by individual experiments (coloured) and both experiments together (black), showing the improvement in precision resulting from the combination of results. Geneva/Saint Petersburg, 1st September 2015. Three years after the announcement of the discovery of a new particle, the so-called Higgs boson, the ATLAS and CMS Collaborations present for the first time combined measurements of many of its properties, at the third annual Large Hadron Collider Physics Conference (LHCP 2015). By combining their analyses of the data collected in 2011 and 2012, ATLAS and CMS...

(Phys.org)—Due to quantum effects, it's possible to build a quantum computer that computes without running—or as the scientists explain, "the result of a computation may be learned without actually running the computer." So far, however, the efficiency of this process, which is called counterfactual computation (CFC), has had an upper limit of 50%, limiting its practical applications. Now in a new paper, scientists have experimentally demonstrated a slightly different version called a "generalized CFC" that has an efficiency of 85% with the potential to reach 100%. This improvement opens the doors to realizing a much greater variety of applications, such...

A team of Antarctic scientists has just verified the existence of cosmic neutrinos — tiny, energetic particles that might hail from far reaches of the Milky Way and beyond. And these ghostly little flecks of matter could hold the key to some of the deepest mysteries of the cosmos. High-energy cosmic neutrinos are thought to be produced by some of the universe’s most violent agents, including black holes, supernovae, and the energetic cores of galaxies. Unchanged as they zip across space and time, these particles may represent something of an intergalactic breadcrumb trail, pointing us in the direction of any...