Free Republic

Concept Black Hole Illustration A team of researchers has affirmed Stephen Hawking’s prediction about the evaporation of black holes via Hawking radiation, though they’ve provided a crucial modification. According to their research, the event horizon (the boundary beyond which nothing can escape a black hole’s gravitational pull) is not as important as previously believed in producing Hawking radiation. Instead, gravity and the curvature of spacetime play significant roles in this process. This insight extends the scope of Hawking radiation to all large objects in the universe, implying that, over a sufficiently long period, everything in the universe could evaporate. Research...

Louisiana State University physicists have leveraged quantum information theory techniques to reveal a mechanism for amplifying, or "stimulating," the production of entanglement in the Hawking effect in a controlled manner. Furthermore, these scientists propose a protocol for testing this idea in the laboratory using artificially produced event horizons. These results have been recently published in Physical Review Letters, "Quantum aspects of stimulated Hawking radiation in an analog white-black hole pair," where Ivan Agullo, Anthony J. Brady and Dimitrios Kranas present these ideas and apply them to optical systems containing the analog of a pair white-black hole. Stephen Hawking added more...

A person falling into a black hole and being stretched while approaching the black hole’s horizon. Credit: Leo Rodriguez and Shanshan Rodriguez, CC BY-ND =================================================================== To solve the mysteries of black holes, a human should just venture into one. However, there is a rather complicated catch: A human can do this only if the respective black hole is supermassive and isolated, and if the person entering the black hole does not expect to report the findings to anyone in the entire universe. We are both physicists who study black holes, albeit from a very safe distance. Black holes are among...

They may not be black or holes. Some astronomers believe there is a massive planet, far beyond the orbit of Neptune, orbiting the sun — but after years of searching, scientists have not found this theoretical world, which they've dubbed "Planet Nine." This has spurred theorists to consider a radical hypothesis: Perhaps Planet Nine is not a planet but rather a small black hole that might be detectable from the theoretical radiation emitted from its edge, so-called Hawking radiation. For centuries, astronomers have used variations in planetary orbits to predict the existence of new planets. When a planet's orbit doesn't...

The researchers' lab-grown black hole was made of a flowing gas of approximately 8,000 rubidium atoms cooled to nearly absolute zero and held in place by a laser beam. They created a mysterious state of matter, known as a Bose-Einstein Condensate (BEC), which allows thousands of atoms to act together in unison as though they were a single atom. Using a second laser beam, the team created a cliff of potential energy, which caused the gas to flow like water rushing down a waterfall, thereby creating an event horizon where one half of the gas was flowing faster than the...

After the first-ever image of a black hole confirmed theories posited by Einstein, it's the late scientist Stephen Hawking's turn to have parts of his life's work vindicated. In a paper published in Nature, scientists say that have verified the scientist's namesake theory, Hawking Radiation, which hypothesized that black holes emit radiation from their surfaces due to a mix of different factors regarding quantum physics and gravity. To verify the theory, scientists at the Technion-Israel Institute of Technology turned to what sounds like mad science: creating their own black hole.

Hawking at Harvard At packed Sanders Theatre, theoretical physicist and cosmologist tackles the contradictory qualities of black holes April 18, 2016 | Editor's Pick Popular Stephanie Mitchell/Harvard Staff Photographer"If determinism — the predictability of the universe — breaks down in black holes, it could break down in other situations. Even worse, if determinism breaks down, we can’t be sure of our past history either. The history books and our memories could just be illusions. It is the past that tells us who we are. Without it, we lose our identity," said Stephen Hawking. By Peter Reuell, Harvard Staff Writer Twitter...

American space agency, the NASA had recently observed flares of X-rays from a black hole, which goes against the conventional notion that they are compact particles with such huge gravity that even light can't escape. Last month NASA announced that two of its space telescopes caught a huge burst of X-ray spewing out of a super massive black hole. These flairs appeared to be be triggered by the eruption of a charged particle from the black hole, which according to conventional belief doesn't let anything out. The latest findings are in accordance with the theory of Indian astrophysicist Abhas Mitra...

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...

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...

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...

Stephen Hawking has shocked physicists by admitting “there are no black holes”. In a paper published online, Professor Hawking instead argues there are “grey holes”. “The absence of event horizons means that there are no black holes—in the sense of regimes from which light can't escape to infinity,” he says in the paper, called Information Preservation and Weather Forecasting For Black Holes.He says that the idea of an event horizon, from which light cannot escape, is flawed. He suggests that instead light rays attempting to rush away from the black hole’s core will be held as though stuck on a...

... Well, even 90 years isn't enough, it seems, so right now, we are entering new waters – the denial of some basic results of general relativity, our modern theory of gravity that has been around and available to everyone since 1916. So in the last week, hundreds of publications informed their readers that it's been "mathematically proven" that the big bang theory is wrong and the black holes don't exist. These nutty claims boil down to some papers by a crackpot named Ms Laura Mersini-Houghton (no, I really, really won't accept her doctorate) who had previously claimed that she...

The current thinking regarding black holes is that they have two very simple parts, an event horizon and a singularity. Because a probe cannot be sent inside a black hole to see what is truly going on, researchers have to rely on theories. The singularity theory suffers from what has come to be known as the "information paradox"—black holes appear to destroy information, which would seem to violate the rules of general relativity, because they follow rules of quantum mechanics instead. This paradox has left deep thinking physicists such as Stephen Hawking uneasy—so much so that he and others have...