Przyk, did you even read my paper? At least the title? The information paradox relates to getting the information out of the black hole; that information never needs to be "gotten" if the event horizon never forms. This is from the introduction to that Nuclear Physics B article: This paper makes the same case that I do, using the same logic. If you want to continue to dismiss this as trivial or obvious then perhaps you and rpenner should send a joint criticism to the journal directly. Please Register or Log in to view the hidden image!
That is trivial. It does not take a paper to say this. You just did it in one sentence. The bulk of your paper is generally irrelevant to the information loss paradox, like I said. Do you think a journal like Nuclear Physics B would publish a paper like the one you've written?
Do you think I can find posts by you indicating that you believe event horizons exist? We already have one in this thread where you try to show that they form in finite time but I noticed that you used about a dozen non-committal qualifiers. I ask you directly, do you think information, ever, has crossed an event horizon?
I honestly don't know -- and I have told you this in the past. So I don't have any belief about this. What would be the point?
You've told me a lot of things in the past, mostly surrounding the fact that event horizons exist and that my doubting of them was incorrect. From here From here The fact is I have years and years of quotes to draw from where you are firmly establishing your position. You do not get to casually dismiss the idea that event horizons now "obviously and trivially" are not created in a finite time. If you want to continue trying to tap dance then go ahead. RPenner took the smart way out and is just passively lurking while "liking" your responses.
There is simply no question that you believed, in 2013, that GR predicts the existence of event horizons in finite time and that the existence of event horizons was the generally accepted view by the community. I'm accustomed to flip-flopping on this forum but I'm particularly frustrated by you trying to change history only because I do respect your intellect and our historical banter, przyk.
Why didn't you quote this: or this one: "Do black holes exist?" and "Do black holes form according to [insert specific theory]?" are different questions. I've told you that in the past too. It seems like you have a general difficulty with reading comprehension. I never said that event horizons obviously and trivially are not created in a finite time. I said this was trivial: Or more specifically, it is trivial given that this is all you have to say, once one takes out the strawman discussion of the information loss paradox in your paper. I touched on the reason for this a few posts ago: Theoretical physics isn't about your opinions and beliefs. It is about how to model things and what you can justify in the context of a given model. Saying something like "maybe event horizons never form, so there would be no information paradox" is pretty worthless on its own because it says nothing about what kind of model of gravity or analysis you need in order to predict that behaviour.
. . . (Above): Theoretical physics isn't about your opinions and beliefs. It is about how to model things and what you can justify in the context of a given model. Not necessarily true, IMO . . . I have utilized many analog, digital, and mathematical 'models' during my career and I have 'observed' that often the model is only as good as the data input into it; to paraphrase someone? : "Garbage IN . . . garbage OUT!". Also, iteration and renormalization often excise/toss-out contextual variables that have value. IMO, You are correct re: "justification of context" . . . . which is often based on preconceived (or consensus) notions, opinions, and beliefs of the investigator(s) and their peers.
You're right, I apologize. You've always been very careful not to commit yourself to anything, but you frequently "speak for the community" I've noticed. If opinions and beliefs are irrelevant in physics why do you feel that the consensus is important? The consensus also believes in evaporating micro black holes, which you have already agreed is a logical contradiction. Do you agree that the physics community believes in a logical contradiction?
I don't "speak for the community". In particular, I am not involved in research on gravitation or black holes or the information loss paradox and I only studied classical general relativity in university. What is happening here, rather, is that your paper is so irrelevant to the discussion on the information loss paradox that even I, a total non-expert on the subject, can see it. You've just so obviously not done any background research on the subject of your own paper. You even admitted in this thread that you still haven't properly learned GR, let alone whatever models of evaporating black holes people are considering. It is important if you hope to advance or change current thinking on a problem that a research community is working on -- you need to know what that community is actually thinking to have a chance to do that. I would have thought that would be obvious. But maybe you don't care about that, and you're happy to claim something that is technically correct or "not wrong" on some level, according to your own definitions, etc., and you don't care if you end up knocking down strawmen or the like. Then no, it is not important to learn the consensus (or, really, much of anything at all) to do that. Yes, RJ. Physicists believe in black holes that simultaneously exist forever and don't exist forever. They are really that stupid.
Although question was asked to przyk, still quite interesting. 1. What is information in your opinion? 2. Don't you think if any mass/energy falls below its schwarzschild radius, it forms the event horizon by definition ? 3. And if you are saying that EH cannot form, then are you saying that BH cannot form and does not exist?
przyk, you said: Perhaps I'm misinterpreting this but you appear to be speaking for the community when you say this is the model which is accepted, and that the community believes in the existence of black hole solutions, singularities and event horizons. You have also said that the community, or some in it, believe that your Kruskal coordinate graph shows that the event horizon forms in finite time. Do you believe that this would adhere to Wald's definition of the event horizon "not existing in the causal past of future null infinity"? You don't see a contradiction here? This is something that we wrestled with years ago and you seem to continue to hold this belief. Time and space are not fungible dimensions like energy and mass. You cannot redefine T and D with U and V and consider them to have the same physical meaning. The mathematical singularity can NOT be trivially removed by a change in coordinates and my rationale is based on logic. There is simply nothing you have said to convince me otherwise. Until I found this specific paper in Nuclear Physics B I thought that the entire physics community had been conned. The God: Yes, I am saying that the black hole, as defined as an area containing an event horizon, cannot form and does not exist. This is true in pure general relativity and doubly true in the presence of any form of "black hole region" evaporation.
Is it same as saying that no BH exist? Are you saying that a mass or energy cannot fall beneath its schwarzschild radius?
I don't remember in what context I said that. I could very well have not been well informed exactly what the consensus is, or it could even have changed since I said that. Like I said, I am not involved in research in this area. So far as I know, the "currently accepted model of black holes" for a long time was what classical GR predicts (i.e., black holes with event horizons that exist forever) until Hawking predicted that black holes should radiate when you take into account quantum field theory. Things get less concrete from there. If you mean the one that I linked to in my first post in this thread, then it is not "my" graph. The Nuclear Physics B paper it comes from refers to it in the introduction as the standard picture people have for evaporating black holes. I don't see why you need to ask me this. Did you look at the diagram? There is an interior part to the black hole that is not in the causal past of future null infinity. So it is a black hole by Wald's definition. Where do you see any contradiction? You haven't really commented on that diagram at all so far. Now you seem to be changing the subject again. This whole thread has been about evaporating black holes. Now it seems you want to discuss the logic of black holes even in purely classical GR. If you think even that isn't settled then why did you bring up Hawking radiation, evaporation, etc., in the first place? That needlessly complicates the discussion since as far as I know there isn't even a completely definite and self-contained theory in that case and it could very well turn out that black holes and event horizons end up not forming for reasons that have nothing to do with logic. So, please, figure out what case you actually want to make, because all I'm getting out of this is that you have some deep personal discomfort with the whole idea of black holes and you're desperately searching for an argument -- any argument -- that will make them go away. What you described above is not a logical argument. You are simply announcing that you don't accept some aspects of relativity theory, i.e., the contraction isn't in GR but between GR and you. You have consistently avoided the thing that would be most likely to convince you: actually learning GR and how to reason about GR according to its own inner logic.
This isn't true. My problem has always been the way GR has been interpreted. 1. Ignoring all quantum effects, do you believe that GR predicts event horizon formation in finite time? 2. Do you think Stephen Hawking utilized the event horizon when he formulated Hawking radiation? 3. Do you agree with the LHC Safety Assessment Group's claim that there is a broad and general consensus that micro black holes have existed and subsequently evaporated? I'm not saying GR is wrong. I'm not saying QM is wrong. I'm saying anyone who claims event horizons don't present a logical contradiction is wrong, and no magical "inner GR logic" ( Please Register or Log in to view the hidden image! ) can circumvent that.
There isn't an interpretation problem with classical GR. GR is about spacetimes. The various classical GR black hole models are all spacetime manifolds which are solutions to the Einstein field equation. That's really all there is to it -- unless you introduce your own beliefs about what spacetime manifolds are acceptable and what ones are not. Classical GR certainly predicts black holes that form from collapsing matter. This is a mathematical question, not a matter of belief. I think there's a derivation in the book by Misner, Thorne, and Wheeler somewhere, for instance. I would generally think of the black hole as forming in "finite time" in that case, but you may get a different answer if you start splitting hairs on the meaning of "finite time". If some particular definition is important to you then the sensible thing to do would be to learn what the black hole formation model is; then you could decide for yourself whether the horizon appears in finite time according to whatever definition you like. I haven't studied Hawking's model, but my understanding is it involves a gravitational singularity and event horizon of some sort. Presumably like what's illustrated in the spacetime diagram I linked to earlier. I don't know, but I have no reason to disagree with the LHC Safety Assessment Group. You may as well admit you are arguing based on faith if you say something like that. If there is a contradiction associated with black holes then either that contradiction comes from within GR (its own inner logic, which you have just admitted you don't care about) or it comes from somewhere else (like your personal worldview). You can't have it both ways.
We're going to keep this simple. Does a micro black hole which has evaporated exist in the causal past of future null infinity?
Hold on. If a micro black hole is created in our lab, and subsequently evaporates which we can verify (as it no longer exists), your claim is that it remains in our infinite causal future?
