'Quantum Hair' Could Resolve Hawking's Black Hole Paradox, Say Scientists (theguardian.com) 96
Stephen Hawking's black hole information paradox has bedevilled scientists for half a century and led some to question the fundamental laws of physics. Now scientists say they may have resolved the infamous problem by showing that black holes have a property known as "quantum hair." From a report: If correct, this would mark a momentous advance in theoretical physics. Prof Xavier Calmet, of the University of Sussex, who led the work, said that after working on the mathematics behind the problem for a decade, his team made a rapid advance last year that gave them confidence that they had finally cracked it. "It was generally assumed within the scientific community that resolving this paradox would require a huge paradigm shift in physics, forcing the potential reformulation of either quantum mechanics or general relativity," said Calmet. "What we found -- and I think is particularly exciting -- is that this isn't necessary."
Hawking's paradox boils down to the following: the rules of quantum physics state that information is conserved. Black holes pose a challenge to this law because once an object enters a black hole, it is essentially gone for good -- along with any information encoded in it. Hawking identified this paradox and for decades it has continued to confound scientists. There have been innumerable proposed solutions, including a "firewall theory" in which information was assumed to burn up before entering the black hole, the "fuzzball theory" in which black holes were thought to have indistinct boundaries, and various exotic branches of string theory. But most of these proposals required rewriting of the laws of quantum mechanics or Einstein's theory of gravity, the two pillars of modern physics.
Hawking's paradox boils down to the following: the rules of quantum physics state that information is conserved. Black holes pose a challenge to this law because once an object enters a black hole, it is essentially gone for good -- along with any information encoded in it. Hawking identified this paradox and for decades it has continued to confound scientists. There have been innumerable proposed solutions, including a "firewall theory" in which information was assumed to burn up before entering the black hole, the "fuzzball theory" in which black holes were thought to have indistinct boundaries, and various exotic branches of string theory. But most of these proposals required rewriting of the laws of quantum mechanics or Einstein's theory of gravity, the two pillars of modern physics.
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All problems solved here.
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"Yes, anon who isn't me, you are very clever."
"Oh thank you anon who definitely is someone else, that is very kind of you. You are also a genius in all fields of thought."
"It is too bad that no one in any field of thought ever listens to us."
"Yes, they are very rude, and their mocking laughter is hurtful, even to a genius who is many levels above them."
"This is very true, totally other person who isn't me!"
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The wonderful thing is that that parts of the standard model seems to be failing. Other than the Higgs Boson, the LHC did not confirm much else. We have increasingly complex means of reconciling theory with observation young scientists are going to have the most ex
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There is a slight problem: "it is not destroyed. It still exists, you just do not have access to it" is operationally indistinguishable from "it is destroyed".
If someone, somewhere, at some point in time could have a theoretical possibility of getting to that information, then there would have been a difference. But there isn't any.
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Whether those two concepts are the same or not may be a matter of how the math is translated into English. I'm willing to accept that those who understand the math are right that there is a paradox, even if I don't really understand it.
Re:I don't see the problem. (Score:4, Insightful)
It means that there seems to be no contradiction with the journalist's simplified description of the scientific journalists' simplified description of a paradox described by actual scientists. The actual formulas however are contradictory. The poster was just doing the typical slashdot hobby of assuming all mysteries in the universe are trivial when seen from the comfort of mom's basement. How simple the world would be if they could just leave the dark and slightly mildewed cellars and explain everything finally.
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That's ridiculous and smacks of anthropocentrism: An assumption that information is only there for "us". Whatever else is inside the black hole has access to the information. It seems you are being biased, only considering the abilities of the parts of the universe outside of a black hole.
There is a clear difference between information which is hidden (e.g. inside a black hole,
The problem is... (Score:3)
.. that over huge cosmological timescales (think 10^triple-digit years) black holes evaporate (google it) and what happens to the information inside. I thought it had been solved by assuming that one of the virtual particle pairs that escaped in the black hole radiation somehow carried away the information but I guess that theory is in the bin now.
Re:The problem is... (Score:4, Informative)
> The problem is ... that over huge cosmological timescales (think 10^triple-digit years) black holes evaporate (google it) and what happens to the information inside.
Exactly
"By contrast, the quantum hair theorem claims to resolve the paradox by bridging the gap between general relativity and quantum mechanics using a new mathematical formulation.
"The name is a nod to the view, based on classical physics, that black holes can be viewed as surprisingly simple objects, defined only by their mass and speed of rotation. The prediction of bald, featureless black holes has been nicknamed the “no-hair theorem” since the 1970s.
"Calmet and his collaborators think the black hole is more complex – or hairy. As matter collapses into a black hole, they suggest, it leaves a faint imprint in its gravitational field. This imprint is referred to as “quantum hair” and, the authors say, would provide the mechanism by which information is preserved during the collapse [or evaporation] of a black hole. Under this theory, two black holes with identical masses and radii, but with different internal composition, would have very subtle differences in their gravitational fields"
"Prof Toby Wiseman, a theoretical physicist at Imperial College London, described the paper as “a good bit of work”, but remained unconvinced that it resolved the decades-old paradox.
"Crucially, he said, the paper suggests it may be possible to get some additional information about what is inside the black hole – but does not show that the phenomenon can account for the entirety of the information that is apparently lost. “That, they haven’t shown and that’s the crux of the paradox,” he said"
https://www.theguardian.com/sc... [theguardian.com]
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The problem with that is that it's only half of something that never existed, and it doesn't cease existing until it unites with it's complement.
Re: I don't see the problem. (Score:2)
Even a small lifespan means it exists, and isn't virtual at all. We can observe those "virtual" particles quite well. Second, if it is destroyed, the energy is still there. That's information. And it can never be destroyed according to thermodynamics. Are you arguing that Newton, Einstein, Hawking and thermodynamics are all wrong? Fascinating. Please direct me to your peer-reviewed theory.
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It takes energy to change information - you have to do work to achieve the change. Whether that means that energy is information is a rather different question - and way above my pay grade.
Re:I don't see the problem. (Score:4, Insightful)
I'm so glad an Anonymous Coward knows better than the actual theoretical physicists.
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Of course they do. Just like they know better than the actual doctors and medical practitioners when it comes to vaccines and covid.
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Anonymous Coward for President!
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Re:I don't see the problem. (Score:5, Informative)
If information falls into a black hole, it is not destroyed. It still exists, you just do not have access to it. It's the equivalent of it being outside the boundary of the visible universe. Nothing is destroyed, no laws are broken. It's still there, in a place you simply cannot see.
As the black hole radiates (Hawking radiation [wikipedia.org]) and evaporates, the information contained within should be released back into the observable universe. But the emitted radiation is dependent only on the mass, charge and angular momentum [wikipedia.org] of the black hole itself and not on the original material that fell into it. This is the paradox.
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But the emitted radiation is dependent only on the mass, charge and angular momentum of the black hole itself and not on the original material that fell into it. This is the paradox.
If I build a machine that inputs all shapes and sizes of marbles and only emits marbles of a certain size is something being lost?
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If I build a machine that inputs all shapes and sizes of marbles and only emits marbles of a certain size is something being lost?
No.
If instead, you put your marbles into a black hole which then emits only thermal energy until the black hole evaporates, then yes. Black holes, while having nearly unlimited storage capacity, make terrible Bags of Holding.
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If instead, you put your marbles into a black hole which then emits only thermal energy until the black hole evaporates, then yes.
What's the difference?
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What's the difference?
The amount of information contained in the original pile of marbles and the resulting set of thermal energy. One can even say the difference is "paradoxical".
Start with "Breakdown of predictability in gravitational collapse [aps.org]" and then follow up with "Black hole information paradox [wikipedia.org]" and references [wikipedia.org].
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The amount of information contained in the original pile of marbles and the resulting set of thermal energy.
I assume people are referring to transactional constraints of QM when they talk about paradoxes and information. No deleting, hiding, peeking, reading, duplicating...ad nausea. I don't understand the relationship between this and product of evaporating black holes.
What fundamentally is the problem with a black box dissimilar things go into and one thing with a given total energy comes out of? Merely normalizing outgoing energy is certainly not something one can claim is a problem by itself so what is the
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I doubt I'll be able to provide any more insight, WaffleMonster, but it is fun to day-drink and chat with you.
Paradoxes don't exist in the real universe. When we find them, they point to our own misunderstandings and make us pay additional attention to the details to try to determine what part of our (mis-)understanding we need to change.
Folks used to see black holes as one way things: stuff goes in and stays in, forever. But if we could see into the black hole, folks thought that we'd find all the proton
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No. This is wrong. The thermal energy contains all the information, but in impossible-to-decode-if-you-are-physical form i.e. totally randomized, but random is only well defined from the point of view of some physical observer (or the set of all physical observers).
The concept of "thermal" is a macroscopic concept, defined for the the "effective" theory that is thermodynamics. Everything emitting t
Another case of information-loss non-paradox: (Score:2)
Macroscopically, the expansion of the universe is
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Yes, but in the Stockholm medal presentation ceremony, he'll be referred to as Ölfissfån.
(so sad that the the information present in the Swedish letters will irretrievable once entering the Slashdot black hole)
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But if I put all my marbles into the black hole, does that mean I've lost my marbles?
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If I build a machine that inputs all shapes and sizes of marbles and only emits marbles of a certain size is something being lost?
Well, yes. The information about what sizes and shapes the marbles were is lost. And sometimes that could be important.
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Speaking as a geologist, I'd add a lot more mineralogy and chemistry to the "glass" question too. Which raises the question of "if you can't read the information contained in a structure, but
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... Which raises the question of "if you can't read the information contained in a structure, but someone else could, does that information exist?" I rather think that it does, otherwise mineralogy exams couldn't exist, and each specimen would be different for each student examining it.
Yes, it does exist. Otherwise you could erase the printing on a page, just by closing your eyes! 8-)
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There is a rhetorical tool [wikipedia.org] which has been popular for several millennia now.
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That's not correct, even though widely assumed to be.
The emitted radiation has unique particularity, derived causally from the complex evolution of the inside of the black hole.
This particularity is effectively random (not predictable) to any outside observer, because a) they lost the ability to track what was going on inside the black hole, and b) what was going on was maximally complex and not trackable by any physical o
Re:I don't see the problem. (Score:5, Insightful)
You are not more clever than the scientist who study this. What you are doing is a very good example of the Dunning Kruger effect. You know nothing about the field, so you have no way to judge that your ideas are completely fucking ridiculous. A smarter person would say "Well, I don't know anything about this, I have never studied the field, so I will not embarrass myself by speaking about it. Anyone with any knowledge would instantly know I'm a moron, speaking out his ass on something I know nothing about. And they would laugh at me." But not you! You are not only ignorant, you are too stupid to assess your ignorance.
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Sorry, still not the right field. Being a scientist though, I would think you would know better. If you aren't lying. But I think you are lying about being a climate scientist. I don't think you have a college degree, to be honest.
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As someone with college degrees, I must admit: college degrees aren't that impressive.
Witness, brother! ;)
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You do realize the AC was implying I was a climate scientist, right? Not that they were. I was fucking with them. I wasn't making any sort of honest statement about college degrees.
To be fair, I doubt the AC in question graduated high school. I'm pretty sure I know which goofball it is, too. One of Slashdot's dumber trolls. Legit, I think they may be eligible for disability income.
Re: I don't see the problem. (Score:2)
The purpose of a degree is to teach people how to learn. The subject is merely a case study.
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The purpose of a degree is to teach people how to learn. The subject is merely a case study.
This is more true than it seems.
No one should exit college thinking they completely know how to do anything. The courses are far "over-simplified", to allow teaching the concepts. Once you get out you will need to "fill in" all those empty spaces. Before that, you can be dangerous... 8-)
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I dunno, I've had several people without such degrees proclaim to me that they wish they had one or more of them. And such degrees can indeed be impressive should they be in a field that is very difficult and obtuse to the average slashdotter. A PhD degree in theoretical cosmology is indeed impressive, much more so than a degree in cosmetology. Either one of those could cause a member of the appropriate sex follow you home from the bar on rare occasion.
Short and Curlies (Score:1)
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Ow, ow, ow, it's all entangled!
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I remember digging a copy of this up on my laptop a few years back. A feminist watching me got pissed off when she saw that I had filed it in Documents/Funny.
tl;dr (Score:2)
Information is encoded on the surface of the black hole in the form of imperceptible variations of the gravity field, so it's a variation on the idea of the holographic principle.
Re: tl;dr (Score:1)
Hawking sensationalism (Score:3)
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Prof. Hawking did not coin the name of the "paradox" nor first came across it: https://en.wikipedia.org/wiki/... [wikipedia.org]. On the contrary, Hawking partially resolved the problem for a subset of the known black hole solutions, which is very different from what the summary states. Can we stop using the name of popular known scientists to attract clicks? I get it about The New Yorker, but ./ should know better...
Based on the editorial content around here for the last few years? Uh, no. No it should not. These editors barely seem capable of readable English. Clickbait is all they know.
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People were making that comment when 6-digit UIDs were a new thing.
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It's only because the kids don't know who Einstein is and never saw him on the talk shows. Unlike Hawking, because that guy got around.
plug (Score:2)
Where’s the beef? (Score:4, Informative)
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You sound infinitely confident about that. Not being a physicist, I don't know how accurate that assertion is, but I do know that people were arguing about the shape of event horizons on rotating (let alone charged) black holes, decades ago.
Whether they were right, or you are right, I don't know. But I do know that the argument was going over my head for decades - so obviously someone disagr
Sure, it was found in Canis Major... (Score:2)
Hair of the dog.
Silly (Score:2)
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I thought you met Maximilian Schell.
Re: sorry guys, black holes are not a thing. (Score:2)
"Black hole propaganda"... right.
Would you care to explain how and where the maths disagree with your idea of how the universe works? Because it seems you haven't thought this one through as well as you should.
The fact that a singularity pops up means that the math has reached its limit at that point, not that the physics of black holes are wrong. We do observe black holes' event horizons and the warped space around them, you know.
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We do observe black holes' event horizons
But not the singularities postulated to lie at the center of black holes.
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The fact that it's a singularity means that we cannot say *what* lies there. If you have an opinion on what's inside a black hole, feel free to share it. But current theory says we don't know.
But if you say "a singularity is not a thing" then I agree, because that's exactly what current theory says. It's a singularity in our math, and *therefore* not a thing we can say much about except "we don't know."
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If you have an opinion on what's inside a black hole, feel free to share it.
A closed universe.
Forget the (simplified) 2D model of space time curvature that continues inside the even horizon, eventually reaching a singularity at it's center. Model a black hole as an infinite discontinuity [blogspot.com] at the event horizon. The space-time curvature inside a black hole eventually 'flattens out', making it a perfectly livable environment (other physical parameters willing).
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The space-time curvature inside a black hole eventually 'flattens out', making it a perfectly livable environment (other physical parameters willing).
Since we can't state with certainty what happens behind the event horizon, this could be true. It could also be rainbows and unicorns, or even a pocket dimension called Hell, behind the event horizon. Who knows?
But if you say the space-time curvature flattens out, you maybe have some theory that describes how that works?
Re: sorry guys, black holes are not a thing. (Score:2)
QM isn't guaranteed to lead to singularities. There's several QM solutions that don't. They still have black holes, but no singularity.
So before criticising something, understand it.
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Or a universe, since if our universe has enough mass it is, itself a black hole.
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A black hole without a singularity is a black hole with quantum loop gravity OR a GR black hole in quantized space.
In either case, nothing can escape and the model is unaltered.
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It may still mean something, we're still calculating. However the closer we get to the black hole the slower the calculations become.
Does anyone understand this? (Score:2)
I don't even understand the logical basis of no-hairs. So you overcome pauli and a whole bunch of shit ends up sharing the same states... so what? What is the big deal?
Re: Does anyone understand this? (Score:2)
The big deal is that there have been many attempts to formulate back holes with hairs, firewalls or some other means of encoding data on the surface but there have always been problems.
Information cannot cross the event horizon, information this side cannot be destroyed, so if had to be kept somehow.
This isn't guaranteed to be any more right than the other attempts, but there's a way to get it to work, somehow.
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The big deal is that there have been many attempts to formulate back holes with hairs, firewalls or some other means of encoding data on the surface but there have always been problems.
Information cannot cross the event horizon, information this side cannot be destroyed, so if had to be kept somehow.
So the idea here is that energy can escape but not information?
Where do people reckon information associated with the escaped energy came from?? nothing?
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No, energy can't escape.
What happens is that the boiling quantum foam on or near the event horizon is sending virtual particles in opposite directions. These virtual particles must be of opposite types, since they average to zero mass and zero energy (so don't violate the conservation laws). When one enters the black hole, the other (now unpaired) particle becomes real.
Now, here I'm not sure of the physics, but physicists hold that the particle emitted always had positive mass and positive energy. Since the
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No, energy can't escape.
Yet at the end of the day the black hole is gone and all of its energy has been emitted.
These virtual particles must be of opposite types, since they average to zero mass and zero energy (so don't violate the conservation laws).
Now, here I'm not sure of the physics, but physicists hold that the particle emitted always had positive mass and positive energy. Since the average remains zero, the particle claimed has negative mass and negative energy.
What prevents the half of the pair that fell back in from effecting the state of the one that didn't?
If you create a negative mass marble and collide it with a positive mass marble you end up with no marbles? All that "information" that comprised both marbles is poof gone or is it just in a bigger box?
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Well, no. It's energy doesn't get emitted, but cancelled out. Because all photons are considered interchangeable, the effect is the same but transactionally it is different.
No information can cross the event horizon, so the half that falls in cannot affect the one outside.
Everything cancels out, so there is no residual information.
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No information can cross the event horizon, so the half that falls in cannot affect the one outside.
Why not? What prevents it? Why does QM care whether one of the pairs is inside or outside of a blackhole?
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Everything cancels out, so there is no residual information.
I would think the one that fell in eventually gets "canceled" and this effects the state of the one that didn't.
Yeah, right (Score:2)
New mathematical formulation means huge paradigm shift in physics would not be necessary
Anything to avoid having to go back over one's homework and look for mistakes.
Somewhere, there's a lowly patent clerk who is round-filing all the applications which include the term "using the Internet" and using the time to work on a solution to straightening the current mess out.
The real problem (Score:2)
Is that you're never certain if you're having a Bad Quantum Hair Day.
Hair...Bald... (Score:2)
Let's compromise on comb-over,