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The Black Hole information loss problem is unsolvable

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101–110 of 143 posts

Re: The Black Hole information loss problem is unsolvable

#101
post #24

As a non-physicist, I've always been hung up on a much simpler paradox: how does radiation escape from a black hole? I thought even light could not escape? Is there an explanation to that?

This is Hawking radiation, which I'm sure wikipedia can explain better than me: https://en.wikipedia.org/wiki/Hawking_radiation > A pair of virtual waves/particles arises just beyond the event horizon due to ordinary quantum effects. Very close to the event horizon, these always manifest as a pair of photons. It may happen that one of these photons passes beyond the event horizon, while the other escapes into the wid…

> The amplification gives rise to a "partner wave", which carries negative energy and passes through the event horizon, where it remains trapped, reducing the total energy of the black hole

Is that the same kind of negative energy that comes up in talk of stabilizing wormholes and building Alcubierre drives?

Re: The Black Hole information loss problem is unsolvable

#103

I don't fully understand the claim that all quantum processes are time-reversible. Aren't there a lot of spontaneous quantum phenomena that aren't?

Quantum processes are described by Schrodinger's equation, that is a linear differential equation in time. Consequently, it's solutions for every possible boundary conditions are always reversible.

So if you could measure an atom precisely enough you could calculate exactly when it decayed from a heavier atom?

Re: The Black Hole information loss problem is unsolvable

#104

Earlier quoted context omitted.

That's true. "Induction works in practice" is merely an empirical fact. But it is a fact. Our bodies embed it already: evolution has worked because the environment has changed slowly enough for advantageous mutations to remain advantageous for long enough to become ubiquitous in the species. But, again, the thesis "empirical evidence doesn't matter" is immune to empirical evidence. Now, if one were to try to construc…

Exactly, and your responses both apply to Sabine's criticism as well. I like the tenor of your second argument, it reminds me of Pascal's wager. That said, you're not really addressing the problem of induction. We have no reason why you'd assign a higher probability to the "law of physics remain constant" to the "laws of physics are flipped in the next second", outside of gut reasoning. If we can use gut reasoning ab…

To be clear, a true "anti-inductivist" as I describe it would be completely deranged and unable to function in life. It's not really relevant except to people who start from a normal perspective and are considering the anti-inductivist hypothesis (usually either because they're studying philosophy or because someone else brought philosophy into the discussion, which is what happened here).

For those people, it is important to realize that anti-inductivism can't be defeated on its own terms. By usual standards (for some definition of "usual"), the space of possible observations one could make is enormous, and the fact that they keep very, very consistently being in accord with the laws of physics as we've discovered them—often to many decimal places—is immense evidence in favor of "physics as we've discovered it" as compared to "anything might happen". Any viable competing theory would have to be reasonably simple (i.e. not include "billions of specific items that explain all prior observations" as axioms) and would have to make almost exactly the same predictions.

("Newtonian mechanics" is reasonably simple and makes similar predictions at the level most people can see, but with specialized equipment and experiments it has been disproven. "God did it" sounds simple, but either the word "God" smuggles in the extremely non-simple "God is a being whose psychological makeup led him to make the following billions of specific decisions that explain all prior observations", or it amounts to "God is a being who chooses to run the universe according to something approximating Einsteinian mechanics"; in that case, it is possible that God might decide to intervene and do something physics would say is impossible, but if you want to say that God will do any specific intervention, you would have to make a less-simple theory that explains why God would do that particular thing and not anything else, and the longer time passes without any verified physically-impossible miracles, the more unlikely most such theories get. "Intelligent beings vaguely like us arose, and decided to simulate our universe, following rules that approximate Einsteinian mechanics" is also possible—not much different from the God-based class of theories.)

Re: The Black Hole information loss problem is unsolvable

#105
post #92
post #72

Earlier quoted context omitted.

I suggest reading https://www.forbes.com/sites/startswithabang/2018/11/03/ask-... Most importantly, he argues that Hawking's own popular explanation (often repeated across the media, about the particle-antiparticle pair) is too simple to be correct: "It's not right, though, in a number of ways. First off, this visualization is not for real particles, but virtual ones. We are trying to describe the quantum vacuum, but…

I wonder how charge evaporates from a charged black hole? And does it do so at a rate that is different from the mass? i.e. does most of the mass evaporate away, and then the charge?

That seems to be an open question. Hawking radiation is not charged, but it also turns out that there is a maximum amount of charge a black hole of a given mass can have, and the lower the mass the lower the maximum allowed charge.

So it would seem that a charged black hole would evaporate by Hawking radiation until it reached the point where any further mass loss would put it over the charge limit. Physicists don’t think it is then simply going to stop radiating, and so what happens then is I believe still quite open.

There was an article in Quanta a few months ago on this: https://www.quantamagazine.org/black-hole-paradoxes-reveal-a...

Re: The Black Hole information loss problem is unsolvable

#106
post #59

Earlier quoted context omitted.

> The information isn't gone, its right -there- in the black hole No, it isn't; it hits the singularity inside of the hole and gets destroyed. At least, that's what Hawking's original model, the one he used to predict that black holes evaporate, says. One way of seeing why Hawking's model had to say this is to combine the following facts about the evaporating black hole and the Hawking radiation in Hawking's model: (…

Except that later Hawking came to the conclusion that black holes do have hairs.

> later Hawking came to the conclusion that black holes do have hairs

Reference, please?

Re: The Black Hole information loss problem is unsolvable

#107
post #56

Earlier quoted context omitted.

> By Sabine's stance, the problem of induction [0] hasn't been "solved" The "problem" of induction is a different kind of problem from the black hole information loss problem. Induction can't be tested against experimental data. Induction isn't a testable hypothesis; it's a strategy we have no choice but to adopt if we want to plan for the future at all. So there is no "problem" of induction at all: it's just somethi…

My point is that there are always going to be equally possible alternative theories which make any problem "unsolvable". I could make a theory that says that gravity works exactly as we think it does, except in about 1000 years will cease to function entirely - and that theory would be equally consistent with observation. I would be equally correct in saying that we do not yet posses the technology (time travel) to f…

> We have to rely on some sort of proxy for the simplicity or elegance of the theory in order to preclude hypotheses like the above.

No, we don't. The rule that precludes your hypothesis is much simpler: the laws of physics don't change with time. That doesn't require the laws of physics to be "simple" or "elegant", and doesn't require anyone's subjective judgment about which laws of physics they think are more beautiful.

Re: The Black Hole information loss problem is unsolvable

#108
post #107

Earlier quoted context omitted.

My point is that there are always going to be equally possible alternative theories which make any problem "unsolvable". I could make a theory that says that gravity works exactly as we think it does, except in about 1000 years will cease to function entirely - and that theory would be equally consistent with observation. I would be equally correct in saying that we do not yet posses the technology (time travel) to f…

> We have to rely on some sort of proxy for the simplicity or elegance of the theory in order to preclude hypotheses like the above. No, we don't. The rule that precludes your hypothesis is much simpler: the laws of physics don't change with time. That doesn't require the laws of physics to be "simple" or "elegant", and doesn't require anyone's subjective judgment about which laws of physics they think are more beaut…

>The rule that precludes your hypothesis is much simpler: the laws of physics don't change with time

Why should we believe this rule?

Re: The Black Hole information loss problem is unsolvable

#109
post #24

As a non-physicist, I've always been hung up on a much simpler paradox: how does radiation escape from a black hole? I thought even light could not escape? Is there an explanation to that?

This is Hawking radiation, which I'm sure wikipedia can explain better than me: https://en.wikipedia.org/wiki/Hawking_radiation > A pair of virtual waves/particles arises just beyond the event horizon due to ordinary quantum effects. Very close to the event horizon, these always manifest as a pair of photons. It may happen that one of these photons passes beyond the event horizon, while the other escapes into the wid…

[deleted]

Re: The Black Hole information loss problem is unsolvable

#110
post #56

> And without data, the question is not which solution to the problem is correct, but which one you like best. I think this is correct to some extent, ultimately unavoidable, and some assumptions can be "inferred" as more reasonable than others, even in the absence of falsification. By Sabine's stance, the problem of induction [0] hasn't been "solved" because we actually have no reason to assume that past events are…

> By Sabine's stance, the problem of induction [0] hasn't been "solved" The "problem" of induction is a different kind of problem from the black hole information loss problem. Induction can't be tested against experimental data. Induction isn't a testable hypothesis; it's a strategy we have no choice but to adopt if we want to plan for the future at all. So there is no "problem" of induction at all: it's just somethi…

Isn’t the information loss problem hypothetical in the first place? I doubt anyone has seriously tried to observe information coming out of a black hole.
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