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"Burning Walls" May Stop Black Hole Formation
KentuckyFC writes "Black holes are thought to form when a star greater than 4 times the mass of the Sun explodes in a supernova and then collapses. The force of this collapse is so great that no known force can stop it. In less massive stars, the collapse cannot overcome so-called neutron degeneracy, the force that stops neutrons from being squashed together. Now a Russian physicist says another effect may be involved. He points out that quantum chromodynamics predicts that when neutrons are squashed together, matter undergoes a phase transition into "subhadronic" matter. This is very different from ordinary matter. In subhadronic form, space is essentially empty. So the phase change creates a sudden reduction in pressure, forcing any ordinary matter in the star to implode into this new vacuum. The result is a massive increase in temperature of this matter that creates a "burning wall" within the supernova. And it is this burning wall that stops the formation of a black hole, not just the degeneracy pressure of neutrons. This should lead to much greater energies inside a supernova than had been thought possible until now. And that's important because it could explain the formation of high energy gamma ray bursts that have long puzzled astrophysicists."
I'm sorry, but after reading the title of the article, all I can think about is all that spicy food I ate last night...
I never like when scientists can't explain a major aspect of something like a black hole. They have models/predictions etc., but there are these little pieces that are missing.
Then someone comes along with an elegant solution that fits perfectly into the existing theory/model/design and suddenly all these unexplained pieces make perfect sense.
That is what science is about. Revelation based on fact, not faith. At the end of the day I think it's a lot more rewarding, although a lot harder to come by.
That's an interesting article. New QCD phases have been postulated for quite a while (colour superconductors etc.) but last time I talked to an expert on it and asked whether it could account for the missing energy in a Supernova (currently SN models seem to fizzle more than explode) his reply was that the phase change was too slow to release enough energy to help the SN go bang. I'll have to read the paper to see it this idea addresses this issue.
Welcome to the Max Planck Subatomic Cavalcade of Freaks! See! the Degenerate Neutron! Behold! the Strange Quark! Find! the Higgs Boson!
"I disapprove of what you say, but I will defend to the death your right to say it." - Evelyn Beatrice Hall, re Voltaire
Reading comprehension FAIL: exactly the opposite is true. Our star will NOT supernova and form a black hole because our sun is EXACTLY one solar mass (being the star that scale is based on) which is less than eight solar masses.
My Babylon
That's exactly what we will do. This hypothesis will be quantified into making predictions about what we will see from supernovae and gamma-ray bursts (and perhaps other events). We will then plan and conduct observations of these events and see if the predictions of this hypothesis are consistent with the new data. A lot of interesting ideas like this come out but then stall for a while as people try translate qualitative ideas into quantitative predictions. Once that happens we can go out and test them.
And that PROVES the existence of God. I mean, what is the chance that OUR sun is EXACTLY one solar mass? There must be hundreds of suns in the universe and we got the ONLY exact one because WE are Gods CHOSEN.
Show all work. Write legibly in #2 pencil or blue or black permanent ink. Do not write on test booklet. Do not start until signaled to do so by your proctor. Destruction of the earth will result in automatic failure. You will have three (3) hours.
"FDA staff reviewers expressed concern about the number of patients who were left out of the study because they died."
There are a lot of very difficult theoretical problems involved in trying to describe the structure of neutron stars. The classic picture of a star made of nothing but neutrons is probably not quite right, and is possibly qualitatively wrong in important ways. There's supposed to be an upper limit on the mass of a neutron star, and the theoretical uncertainties get greater as you get closer to this mass limit. E.g., it's possible that you get quark stars. We just don't know, because we don't know the behavior of the strong and weak nuclear forces with sufficient precision to be able to extrapolate to these extreme conditions.
Given all that uncertainty, which has existed for many decades, it's not at all surprising to me that there's a corresponding uncertainty about the conditions under which a neutron star is or isn't unstable with respect to collapse into a black hole. The paper, which is linked to from the end of the Technology Review article, is pretty heavy going. My field is nuclear physics, not relativistic astrophysics, and I had a hard time understanding it. The author's English is also pretty hard to understand, so it's hard to tell exactly what he's saying his conclusions are. But if you look at the end, he seems to be suggesting that black holes actually do not form.
I wonder to what extent existing observations constrain this idea. For instance, we know that the Sagittarius A* object at the center of our galaxy has a mass of at least 3.7 million solar masses and a radius of less than 6.25 light-hours. It would be interesting to know what he proposes this object is, if he says it's not a black hole.
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