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Even gluttons can't eat forever. When black holes at the hearts of galaxies swell to 50 billion times the mass of our sun, they may lose the discs of gas they use as cosmic feedlots. Most galaxies host a supermassive black hole at their centre. Around this is a region of space where gas settles into an orbiting disc. The gas can lose energy and fall inwards, feeding the black hole. But these discs are known to be unstable and prone to crumbling into stars. Theoretically, a black hole could grow so big that it swallows up the stable part...

Mysterious high-energy particles known as cosmic rays zip through space at a wide range of energies, some millions of times greater than those produced in the world’s most powerful atom smasher. Scientists have long thought cosmic rays from inside our galaxy come from supernova explosions, but a new study has fingered a second source: the supermassive black hole at the heart of the Milky Way. With this new result, the search for cosmic ray origins, which has frustrated scientists for more than 100 years, has taken an unexpected new twist. “It’s very exciting,” says astrophysicist Andrew Taylor of the Dublin...

Explanation: Just press play to watch two black holes merge. Inspired by the first direct detection of gravitational waves by LIGO, this simulation video plays in slow motion but would take about one third of a second if run in real time. Set on a cosmic stage the black holes are posed in front of stars, gas, and dust. Their extreme gravity lenses the light from behind them into Einstein rings as they spiral closer and finally merge into one. The otherwise invisible gravitational waves generated as the massive objects rapidly coalesce cause the visible image to ripple and slosh...

Explanation: Gravitational radiation has been directly detected. The first-ever detection was made by both facilities of the Laser Interferometer Gravitational-Wave Observatory (LIGO) in Washington and Louisiana simultaneously last September. After numerous consistency checks, the resulting 5-sigma discovery was published today. The measured gravitational waves match those expected from two large black holes merging after a death spiral in a distant galaxy, with the resulting new black hole momentarily vibrating in a rapid ringdown. A phenomenon predicted by Einstein, the historic discovery confirms a cornerstone of humanity's understanding of gravity and basic physics. It is also the most direct detection of...

Black holes may sport a luxurious head of "hair" made up of ghostly, zero-energy particles, says a new hypothesis proposed by Stephen Hawking and other physicists. The new paper, which was published online Jan. 5 in the preprint journal arXiv, proposes that at least some of the information devoured by a black hole is stored in these electric hairs. Still, the new proposal doesn't prove that all the information that enters a black hole is preserved.

Stephen Hawking's New Black-Hole Paper, Translated: An Interview with Co-Author Andrew Strominger The Harvard string theorist explains the collaboration's long-awaited research on the black-hole information paradox Share on Facebook Share on Twitter Share on Reddit Email Print Share via Google+Stumble Upon Penrose diagram for a semiclassical evaporating black hole, as presented in "Soft Hair on Black Holes." CREDIT: Prahar Mitra In the mid 1970s, Stephen Hawking made a string of unnerving discoveries about black holes—that they could evaporate, even explode, and destroy all information about what had fallen in. Physicists spent the next 40 years sorting through the wreckage. Then last year, at a...

KISSIMMEE, FLORIDA--Most, if not all, galaxies have supermassive black holes at their centers surrounded by dense clouds of stars. Now, researchers have found one that seems to have lost almost its entire entourage. The team, which reported its find here today at the annual meeting of the American Astronomical Society, says it doesn't know what stripped the stars away. But it has put forward a tantalizing possibility: The object could be an extremely rare medium-sized black hole, which theorists have predicted but observers have never seen. The unusual black hole sits about 1 billion light-years from Earth in SDSS J1126+2944,...

Black holes earn their name because their gravity is so strong not even light can escape from them. Oddly, though, physicists have come up with a bit of theoretical sleight of hand to retrieve a speck of information that's been dropped into a black hole. The calculation touches on one of the biggest mysteries in physics: how all of the information trapped in a black hole leaks out as the black hole "evaporates." Many theorists think that must happen, but they don't know how. Unfortunately for them, the new scheme may do more to underscore the difficulty of the larger...

NASA/CXC/Univ of Texas/E Schlegel et al Image caption The two waves of hot, X-ray emitting gas were seen in this image from Chandra ================================================================================================================ Astronomers have spotted two huge waves of gas being "burped" by the black hole at the heart of a nearby galaxy. The swathes of hot gas, detected in X-ray images from Nasa's Chandra space telescope, appear to be sweeping cooler hydrogen gas ahead of them. This vast, rippling belch is taking place in NGC 5195 - a small, neglected sibling of the "Whirlpool Galaxy", 26 million light years away. That makes it one of the closest...

Black holes can only grow if they have a gas disc to feed on NASA Goddard Space Flight Center/Flickr ======================================================================================================== Black holes can only grow to 50 billion times the mass of the Sun, before they lose their only source of 'food' and stop growing. Scientists discovered that black holes have a size limit, as when it gets so big, the gas which feeds the great void loses its energy, and falls into the unknown. A researcher from the University of Leicester analysed the disc of gas which surrounds supermassive black holes at the centre of galaxies. He found that...

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 apocalypse is still on, apparently — at least in a galaxy about 3.5 billion light-years from here. Last winter, a team of Caltech astronomers reported that two supermassive black holes appeared to be spiraling together toward a cataclysmic collision that could bring down the curtains in that galaxy. The evidence was a rhythmic flickering from the galaxy’s nucleus, a quasar known as PG 1302-102, which Matthew Graham and his colleagues interpreted as the fatal mating dance of a pair of black holes with a total mass of more than a billion suns. Their merger, the astronomers calculated, could release...

In the center of most galaxies (ours included) there is a supermassive black hole that holds everything together. However, one galaxy 10.5 billion light years away looks like it might have two black holes, and just like in Highlander, there can be only one. Scientists believe the pair are going to crash into each other in just 21 years. This could provide an unprecedented opportunity to observe the mind-boggling physics of such an event. The galaxy in question doesn’t have a snazzy name — it’s known only as PSO J334.2028+01.4075. It’s what is known as a quasar, or an “active...

“Star Trek” introduced the world outside of rocket science circles to the concept of warp drive – the propulsion system that allowed the starship Enterprise to travel faster than the speed of light. Warp speed is the holy grail that would let us explore the universe safely surrounded and protected by a space-distorting warp field. After watching the SpaceX rocket recently just try to land on a platform, you’d think this ability is years if not decades away. Yet the buzz on space websites is that NASA may have accidentally discovered a way to create a warp field. Wait, what?...

Wormholes Untangle a Black Hole Paradox A bold new idea aims to link two famously discordant descriptions of nature. In doing so, it may also reveal how space-time owes its existence to the spooky connections of quantum information. By: K.C. ColeApril 24, 2015 Comments (19) One hundred years after Albert Einstein developed his general theory of relativity, physicists are still stuck with perhaps the biggest incompatibility problem in the universe. The smoothly warped space-time landscape that Einstein described is like a painting by Salvador Dalí — seamless, unbroken, geometric. But the quantum particles that occupy this space are more like...

The "information loss paradox" in black holes—a problem that has plagued physics for nearly 40 years—may not exist. Shred a document, and you can piece it back together. Burn a book, and you could theoretically do the same. But send information into a black hole, and it's lost forever. That's what some physicists have argued for years: That black holes are the ultimate vaults, entities that suck in information and then evaporate without leaving behind any clues as to what they once contained. But new research shows that this perspective may not be correct. "According to our work, information isn't...

That’s the conclusion reached by one researcher from the University of North Carolina: black holes can’t exist in our Universe — not mathematically, anyway. “I’m still not over the shock,” said Laura Mersini-Houghton, associate physics professor at UNC-Chapel Hill. “We’ve been studying this problem for a more than 50 years and this solution gives us a lot to think about.” In a news article spotlighted by UNC the scenario suggested by Mersini-Houghton is briefly explained. Basically, when a massive star reaches the end of its life and collapses under its own gravity after blasting its outer layers into space —...

Explanation: What's happening at the center of active galaxy 3C 75? The two bright sources at the center of this composite x-ray (blue)/ radio (pink) image are co-orbiting supermassive black holes powering the giant radio source 3C 75. Surrounded by multimillion degree x-ray emitting gas, and blasting out jets of relativistic particles the supermassive black holes are separated by 25,000 light-years. At the cores of two merging galaxies in the Abell 400 galaxy cluster they are some 300 million light-years away. Astronomers conclude that these two supermassive black holes are bound together by gravity in a binary system in part...

Explanation: In the center of a swirling whirlpool of hot gas is likely a beast that has never been seen directly: a black hole. Studies of the bright light emitted by the swirling gas frequently indicate not only that a black hole is present, but also likely attributes. The gas surrounding GRO J1655-40, for example, has been found to display an unusual flickering at a rate of 450 times a second. Given a previous mass estimate for the central object of seven times the mass of our Sun, the rate of the fast flickering can be explained by a black...

An Indian theoretical physicist who questioned the existence of black holes and thereby challenged Stephen Hawking of Britain at last feels vindicated. But he is sad. Abhas Mitra, at the Bhabha Atomic Research Centre (BARC) in Mumbai, was perhaps the first and the only scientist who had the guts to openly challenge Hawking of Cambridge University who is regarded by many as the modern-day Einstein. For over 30 years Hawking and his followers were perpetuating the theory that black holes -- resulting from gravitational collapse of massive stars -- destroy everything that falls into them preventing even light or information...