Study Confirms Einstein Prediction: Black Holes Have a 'Plunging Region' (cnn.com) 61
"Albert Einstein was right," reports CNN. "There is an area at the edge of black holes where matter can no longer stay in orbit and instead falls in, as predicted by his theory of gravity."
The proof came by combining NASA's earth-orbiting NuSTAR telescope with the NICER telescope on the International Space Station to detect X-rays: A team of astronomers has for the first time observed this area — called the "plunging region" — in a black hole about 10,000 light-years from Earth. "We've been ignoring this region, because we didn't have the data," said research scientist Andrew Mummery, lead author of the study published Thursday in the journal Monthly Notices of the Royal Astronomical Society. "But now that we do, we couldn't explain it any other way."
Mummery — also a Fellow in Oxford's physics department — told CNN, "We went out searching for this one specifically — that was always the plan. We've argued about whether we'd ever be able to find it for a really long time. People said it would be impossible, so confirming it's there is really exciting."
Mummery described the plunging region as "like the edge of a waterfall." Unlike the event horizon, which is closer to the center of the black hole and doesn't let anything escape, including light and radiation, in the "plunging region" light can still escape, but matter is doomed by the powerful gravitational pull, Mummery explained. The study's findings could help astronomers better understand the formation and evolution of black holes. "We can really learn about them by studying this region, because it's right at the edge, so it gives us the most information," Mummery said...
According to Christopher Reynolds, a professor of astronomy at the University of Maryland, College Park, finding actual evidence for the "plunging region" is an important step that will let scientists significantly refine models for how matter behaves around a black hole. "For example, it can be used to measure the rotation rate of the black hole," said Reynolds, who was not involved in the study.
The proof came by combining NASA's earth-orbiting NuSTAR telescope with the NICER telescope on the International Space Station to detect X-rays: A team of astronomers has for the first time observed this area — called the "plunging region" — in a black hole about 10,000 light-years from Earth. "We've been ignoring this region, because we didn't have the data," said research scientist Andrew Mummery, lead author of the study published Thursday in the journal Monthly Notices of the Royal Astronomical Society. "But now that we do, we couldn't explain it any other way."
Mummery — also a Fellow in Oxford's physics department — told CNN, "We went out searching for this one specifically — that was always the plan. We've argued about whether we'd ever be able to find it for a really long time. People said it would be impossible, so confirming it's there is really exciting."
Mummery described the plunging region as "like the edge of a waterfall." Unlike the event horizon, which is closer to the center of the black hole and doesn't let anything escape, including light and radiation, in the "plunging region" light can still escape, but matter is doomed by the powerful gravitational pull, Mummery explained. The study's findings could help astronomers better understand the formation and evolution of black holes. "We can really learn about them by studying this region, because it's right at the edge, so it gives us the most information," Mummery said...
According to Christopher Reynolds, a professor of astronomy at the University of Maryland, College Park, finding actual evidence for the "plunging region" is an important step that will let scientists significantly refine models for how matter behaves around a black hole. "For example, it can be used to measure the rotation rate of the black hole," said Reynolds, who was not involved in the study.
This was in doubt? (Score:3, Interesting)
I'm no astrophysics by any measure but it seems like a common sense idea that a black hole would have a distance at which light can still squirm out but heavier masses will get pulled in.
Was this some huge academic astrophysicist-world dispute us normies didn't know about?
Re: This was in doubt? (Score:2)
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Yea, and if there was a doubt, what was the presumed mechanism of it *not* happening?
I assume anything with non-zero rest mass must move with speeds lower than max, right?, hence its "event" (point of no-return) horizon is farther out of the center of the black hole, where escape velocity is lower.
Although, with speeds c there is theoretical limit on how much mass can move so fast (well there is the energy required to accelerate it so perhaps there is some balance of what's possible)? And, when speeds spee
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the "common sense" or classical physics view would be that matter could orbit arbitrarily close to the event horizon.
Yet that is not the case. Why?
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why not? one would think that with enough kinetic energy a particle with mass could be zooming around close to the event horizon, however with other reply with link jfdavis668 shared there is a GR effect that makes it impossible to orbit any closer than 3 times the Schwartzchild radius for particles with mass, it's unstable any closer. That's actually pretty far away, fascinating!
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What if black holes have tides so things fall away from it as they orbit, like the Moon is getting farther away from the Earth?
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actually, Einstein himself didn't come up with any notion of black holes and doubted they could form even as late as 1939. Worth noting that the math of a black hole forming has intractable equations no one can solve. Instead, we have models of four kinds of eternal black holes that always existed and always will exist that satisfy GR. The real things we observe could be quite different from those models, maybe totally different from event horizon on down!
Re: This was in doubt? (Score:2)
Re: This was in doubt? (Score:4, Interesting)
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thanks, very interesting stuff and purely due to general relativity, unlike thinking a particle with enough velocity could orbit at any distance. 3 times the S. radius, that's pretty far out actually!
Re: This was in doubt? (Score:5, Informative)
The event horizon is the distance that orbital speed is the speed of light.
No, the event horizon is where the escape velocity is the speed of light. This is larger than the orbital velocity. because, any object with this velocity will escape the gravitational well unlike orbital velocity where it cannot escape since it is in a bound orbit.
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Why can't it escape like the Moon is getting farther away from the Earth?
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I am no astrophysicists, but it seems like common sense that in real life there are no "singularities" of any kind. Something that is beaten hard unto you early in your physics course is that to get a meaningful, physical solution in a situation where exponents arise in your answer is to find a way to multiply them by zero and get rid of them.
But once you get your BSc, stop doing problems and start drinking seriously and write grant proposals and articles, that common sense evaporates, and you come up with
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I am no astrophysicists, but it seems like common sense that in real life there are no "singularities" of any kind.
Nature does not care what you think "common sense" says it should do. If it did we would not have quantum mechanics.
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Quantum mechanics isn't "nature", it is a mathematical model.
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QED only. Everything else is, like, 3 to 6 sigmas off, depending on what particular dataset your coefficients come from :)
And QFT isn't QM anyway.
Try again.
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Have you heard about how quantum mechanics predicts a vacuum energy that is 120 orders of magnitude greater than observed? How can you claim prediction accuracy for a field that has produced what is commonly referred to as "the worst prediction in all of physics"?
Re:This was in doubt? (Score:5, Informative)
If you take the known fundamental particles and couplings in QFT, you can calculate the energy density of the vacuum based on Feynman diagrams of various self-interactions. Well, these calculations are well known to diverge and it has been known in QFT almost since its creation that these divergences mean that your theory is incomplete. The divergence at work here is known as UV divergence - blowing up at high energy. This is a consequence of what are called radiative corrections: a lone particle can split up into two photons (or two Ws or Z0s or Higgses) which then recombine into the particle. The problem is that the time this lasts can be arbitrarily short, which means the energy of those bosons is arbitrarily high. When you integrate it up, you get a value that diverges as you let the upper bound you're integrating to grow - a UV divergence.
The way that these are resolved is by "completing" the theory, which means introducing the "missing" physics at higher energies which cause the problematic self-interactions to switch off. It's a bit like the way the Bose-Einstein distribution "fixes" the OG UV catastrophe, of blackbody radiation - at photon energies larger than the temperature, the BE distribution says you very quickly have zero photons per mode instead of one, thereby effectively truncating the integral of ^3 that was blowing up at large
The "prediction" you're crowing about as if it invalidates QFT is the answer to the silly hypothetical, "what if we assume absolutely no new physics happens between 200GeV and 12200000000000000000000000000GeV, do our radiative correction calculation for the vacuum self energy and then just plug in the Planck energy as the upper bound?" Sure as shit, the number is ludicrous. It's about as serious of a "prediction" as writing down the classical physics T^4 blackbody radiation power and saying "let's just plug in the Plank temperature for T" and observing that lo, the answer is in fact ridiculous is a "prediction." And it's useful only for the exact same purpose - to demonstrate that, manifestly, some unaccounted for physics is intervening to cut off the diverging integrand at a much lower point.
This [wikipedia.org] is how QFT "claims prediction accuracy."
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Again, QED is correct and precise. This does not hold for the other QFT incarnations, where the difference between prediction and actual value is huge.
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Again, QED is correct and precise.
So is the entire Standard Model - at least so far we have failed to collect any data that are inconsistent with it.
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The "entire Standard Model" is kinda wrong, everything in it that isn't QED is away from the predicted values by at least a few sigmas, despite (or because of, take your pick) of the precision in measurements that is available :)
Sometimes it is way, way worse than that. How many "quarks" are there in a proton, remind me?
And, of course, only about 85% of the mass of the Universe is, like, completely "inconsistent with it". Oops, I mean, all the mass in the Universe is "inconsistent with it", because SM doesn
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I'm not going to waste my time trying to explain how sea vs valence quarks work, how the Higgs mechanism gives mass to vector bosons, or how full of shit the idea that the the Higgs was discovered by "data massaging by only one research group in the world, again, within 3 or 4 (I forget) sigmas of where it should be" is.
I will say this much because it's short - there was no such thing as a prediction of where the Higgs "should be." The Higgs mass is
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Of course you're not ;)
Real World vs Roadrunner (Score:2)
The "entire Standard Model" is kinda wrong, everything in it that isn't QED is away from the predicted values by at least a few sigmas
That is simply not at all true. The SM is entirely consistent. Yes, there are the _occassional_ measurements that are a few sigma away from the SM prediction but this is _exactly_ what you expect. Remember only two in three measurements are within one sigma and only 19 in 20 within 2 sigma. When you make hundreds of measurements having some 2-3 sigma away simply means that you have your uncertainties correct - if they were all within one sigma that would mean your uncertainties are too large.
Sometimes it is way, way worse than that. How many "quarks" are there in a proton, remind me?
As many as y
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What about "my theory is incomplete" means that the cherry-picked predictions it happens to be right about say anything about its validity?
In other words, were the Romans able to build bridges and aqueducts that have stood the test of time, using theory that made predictions based on the assumption that heavier things fell faster than lighter things?
What if predictive success says as much about your underlying theory as it did about epicycles?
Not Just QFT (Score:2)
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There are no "experimental proofs", ignoramus. The experiment doesn't provide "proof", it provides evidence and limits within which a model is considered an adequate description of "nature" for some purpose.
It is well-known where the QM model is invalid and does not work, for example.
Re: This was in doubt? (Score:2)
Common sense is based on life experience, and nobody has any life experience with black holes. Therefore, trying to use common sense to reason about black holes is a fool's errand.
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Show me a single thing in the universe that we have direct observational data about, which disproves the common sense that there are no physical "singularities" and I'll buy your point.
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How singular are bands in rocks at scales from kilometer to micrometer?
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Not singular at all.
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How singular is an observer who denies singularities in nature evident to any other observer that does not share his peculiar mood affiliation, would you guess?
To put it another way, aren't we just talking about personal preferences and cherry-picking and handwaving and hallucinating coherent theories to explain singularly incoherent and noisy actual data? So what gives your idiosyncratic personal preference for the current consensus any real validity other than pure popularity, which has so often proven an
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who denies singularities in nature evident to any other observer
Singularities are "evident" only in theoretical papers. They do not exist in nature, because they are completely non-physical, as they imply unlimited something, and as far as our experience in things physical goes, there are no non-physical physical things.
So, wherever you see "singularity" in a piece of theoretical work, you're actually seeing "I don't know".
That's all.
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What kind of hubris leads you to think that that "I don't know" has to be reducible to some local experience of your own, though? What if you are handwaving away innumerable singularities all around you, under the pure assumption that all those "i don't know"s are explainable using the most naively realist interpretation of the current consensus on the rules of physics?
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What if you are handwaving away innumerable singularities all around you
Indeed. What if I were walking around, performing successfully divisions by zero that go against everything we know about physics?
I would be able to time-travel, I'd have at my disposal several perpetual engines to choose from, superconductivity at any temperature, FTL travel and who knows what else.
Alas, my naïveté has prevented me from enjoying these apparently multiple manifestations of singularity to my own detriment... How disappointing :)
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Can this sentence be a lie?
Is your experience cherry-picked?
Why could suddenly everyone run 4-minute miles after the first guy did? Are your barriers just psychological?
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Unless you happen to have an example of a physical singularity that can be verified by an experiment, and a sufficiently detailed description thereof, continuing this conversation appears quite pointless.
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As the curvature of space becomes dominated by higher-order post-Newtonian terms near the event horizon, stable circular orbits are no longer possible. The slightest disturbance will make a particle spir
"Albert Einstein was right" (Score:1)
"Physics, bitches!" (Mic drop)
-Einstein
Einstein rejected the notion of Black Holes (Score:2)
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If the current consensus is that the universe has turned out to be stranger than even Einstein could imagine, what gives it the hubris to think it has it all figured out?
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The current consensus is that it is unclear what's happening inside a "black hole". Hence a convenient mathematical crutch is used to skirt this over until there is enough understanding to described it. It may not be possible to model under what's known as "Einsteinian interpretation" of relativity, though :)
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The plunging region this story is talking about is outside the event horizon. It has nothing to do with a singularity, real or not.
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There's more, Einstein didn't even predict black holes, they were predicted by a bloke called Karl Schwarzschild.
Rawr! (Score:2)
Ah-ooo-gah!
What about white dwarves or pulsars? (Score:2)
While, by definition, only black holes can have relativistic event horizons that capture everything, even light, can't other extra-dense objects have such "plunging regions" where orbits become impossible to maintain?
Also, in a possibly unrelated note, AFAIK, any macroscopic object close enough to, for example, a pulsar, is expected to quickly be pulverized apart by the tidal forces. Is this somehow related?
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Yes, neutron stars are also expected to have regions where there are no stable orbits. For anything less dense, the innermost stable orbit is below the surface.
The innermost stable orbit isn't related to the Roche limit or tides.
Obligatopry (Score:2)
"Study Confirms Einstein Prediction: Black Holes Have a 'Plunging Region' "
Insert obligatory "So does your mom" joke here...