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The Black Hole information loss problem is unsolvable

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Re: The Black Hole information loss problem is unsolvable

#91

Post by effie »

pdonis wrote: post #74
effie wrote: post #66

Earlier quoted context omitted.

> The hole itself cannot contain any information other than its mass, charge, and spin... which is far too little information Maybe the information gets encoded in digits of value of mass expressed in some unit. There is enough digits to store any finite number of bits.

> Maybe the information gets encoded in digits of value of mass expressed in some unit. No, it can't, not all the information. Two objects of the same mass but different internal composition would add the same mass to the hole, but would be described by different information. So the hole can't store in the value of its mass which of the two objects fell in. More generally, a hole of, say, ten Solar masses could have…

But why do you assume two objects of same mass but different composition will add the same mass to the black hole? Different composition means different interactions during the fall and different amount of radiated energy. Infinite number of bits can be encoded in single real number. It is hard to measure more than few digits of it, but so it is hard to measure all the information.

Re: The Black Hole information loss problem is unsolvable

#92

Post by flubert »

acqq wrote: post #72
pjungwir wrote: post #18

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?

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?

Re: The Black Hole information loss problem is unsolvable

#93

Post by phkahler »

wwarner wrote: post #71

Her frustration with the priorities of theoretical physics probably is justified, but in this case I disagree with @skdh. Her claim is that any solution for the BHIP cannot be falsified, and that strikes me as too pessimistic for two reasons. First, look at the results of pushing the theory harder with respect to spinning black holes. Many predictions of Kerr's theory have been observed, even if the ring singularity…

>> Her claim is that any solution for the BHIP cannot be falsified, and that strikes me as too pessimistic for two reasons.

No. She said there isn't any data. I know the word falsify has become prominent in the last 15 years or so, but a "theory" that doesn't agree with some real world data is just a hypothesis. In other words a theory needs confirmation in addition to not being falsified. This is where the divide should exist between physics and mathematics. You can have a bunch of cool math, but that's not physics. It's not scientific theory by itself. You can hypothesize that it describes the real world, but until there is confirming evidence that assertion is just mental self-gratification.

Re: The Black Hole information loss problem is unsolvable

#94

Post by BMSmnqXAE4yfe1 »

In what sense thermal radiation is "random"? Normal thermal radiation is only random in the sense that it's very hard to compute all the photons given the initial states of all the electrons etc, but it's possible in principle. Does black hole have an internal state, that depends on the states of all the particles that fell into it? If so, the emanating radiation can be computed from that internal state, so information is preserved.

Re: The Black Hole information loss problem is unsolvable

#95

Post by pdonis »

effie wrote: post #91
pdonis wrote: post #74

Earlier quoted context omitted.

> Maybe the information gets encoded in digits of value of mass expressed in some unit. No, it can't, not all the information. Two objects of the same mass but different internal composition would add the same mass to the hole, but would be described by different information. So the hole can't store in the value of its mass which of the two objects fell in. More generally, a hole of, say, ten Solar masses could have…

But why do you assume two objects of same mass but different composition will add the same mass to the black hole? Different composition means different interactions during the fall and different amount of radiated energy. Infinite number of bits can be encoded in single real number. It is hard to measure more than few digits of it, but so it is hard to measure all the information.

> why do you assume two objects of same mass but different composition will add the same mass to the black hole?

Because that's what the physics says. See below.

> Different composition means different interactions during the fall and different amount of radiated energy.

All of that can be taken into account before the object falls into the hole; the observer outside can measure it all and deduct it from the mass he expects to be added to the hole.

We are talking about the mass that gets added after all that; and for any given mass added to the hole after all those things are taken into account, there are many different possible combinations of objects falling into the hole that can add that mass.

> Infinite number of bits can be encoded in single real number.

We are not talking about math, we are talking about physics. The number of bits that can be stored in an object of finite size is finite as far as physics is concerned.

Re: The Black Hole information loss problem is unsolvable

#96

Post by BMSmnqXAE4yfe1 »

pdonis wrote: post #59
xevrem wrote: post #38

I still don't understand what they mean by "loss". Why is this even a problem? The information isn't gone, its right -there- in the black hole, which until proven otherwise, is part of the universe. Until someone can prove the universe cares whether the info is in a black hole or not, its not really a problem is it? If anything the universe usually shows it doesn't care what we humans think, its going to do its own t…

> 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.

Re: The Black Hole information loss problem is unsolvable

#97

Post by mcguire »

BMSmnqXAE4yfe1 wrote: post #94

In what sense thermal radiation is "random"? Normal thermal radiation is only random in the sense that it's very hard to compute all the photons given the initial states of all the electrons etc, but it's possible in principle. Does black hole have an internal state, that depends on the states of all the particles that fell into it? If so, the emanating radiation can be computed from that internal state, so informati…

"Does black hole have an internal state, that depends on the states of all the particles that fell into it? If so, the emanating radiation can be computed from that internal state, so information is preserved."

If I understand, the short answer from Stephen Hawking is "no." The only properties they have is mass, angular momentum, and charge.

Re: The Black Hole information loss problem is unsolvable

#98

Post by PeterisP »

adzm wrote: post #24
pjungwir wrote: post #18

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 big question to me is whether Hawking radiation is actually a real thing? I mean, the hypothesis is interesting and the math seems to work out, but at least according to that page there is no experimental evidence yet of it actually existing; we have some experiments that might provide some data about the existence of Hawking radiation in the future, but as of now it seems just an unfalsifiable hypothesis. Is there any observational data that requires Hawking radiation to explain it? It's not my field, so I really don't know and I'd be happy to be proven wrong.

Does it make sense to worry about paradoxes created by black holes evaporating, if we have no evidence that they actually do evaporate in our physical reality?

Re: The Black Hole information loss problem is unsolvable

#99

Post by ZeteticElench »

jordan_curve wrote: post #90
shaded-enmity wrote: post #73

Earlier quoted context omitted.

So is this survivorship bias or something else? I don't understand your point. I have a white wall in front of me. If I take a brush and red paint and paint a big red circle on the wall, are you saying that the big red circle "just happens to be there" with no relationship to the brush, red paint and my actions?

You only know that there will be a red spot on the wall based on your past experiences with the physical world. Why should we believe our experiences in the past are at all relevant to the future? We haven’t lived in the future. The laws of gravity could be totally different. All of our data about gravity is equally consistent with the theory “If I drop an apple it will fall only if it is before December 2020” as it…

"Why should we believe our experiences in the past are at all relevant to the future?"

I can glibly say because it is utterly insane and silly to argue otherwise due to the immense success of science to explain how the world works and produce sophisticated technology.

I could also take a Bayesian probability approach and assume some arbitrary prior 0 < p < 1 for the probability that when you apply paint to a brush and place that brush in contact with a white wall and move the brush in a circle a red circle will appear with the exact same size and the circle the brush moved in. Use the Bayesian formula to update your probability and then repeat a few thousand times. The probability will approach 1.

Re: The Black Hole information loss problem is unsolvable

#100

Post by ZeteticElench »

dnautics wrote: post #81
burrows wrote: post #37

Earlier quoted context omitted.

What evidence do we have that causality will continue to “exist”?

we don't. It's the central faith of science that causality is a thing. You can't argue that causality is real because it's always worked; that is begging the question.

Not at all, something as simple as having two boxes and putting an object in one of them and then checking them at regular intervals two verify that the object is always in the box you placed it in and never in the box you didn't is proof of causality.
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