6 ms·

Black holes may be brick walls that bounce information back out

37 points by bootload 11y ago

guard-of-terra 11y ago
I find this black hole information debate akin to medieval ramblings on amount of angels dancing on diamond pin head. Can we please move on a little and come back when we have new angle?
- mojuba 11y ago
  Exactly. I call it exploitation of the unknown. You can generate lots of "theories" by just combining a couple of mysterious things into one. For example, something that hasn't been tried yet afaict, is a theory that black holes are a gateway between the physical world and human consciousness (or self-awareness).
  - LoSboccacc 11y ago
    Oh i like the what if games. Black hole (as singularities that may have formed without collapsing stars) played a central role in early universe by swallowing matter and anti matter and radiating energy by hawking radiation which then fueled energy decay into standard matter, and that may explain the current imbalance between matter and anti matter or it may be mad internet rambling. Still medium worthy?
    - guard-of-terra 11y ago
      Your theory is so important that it will get evaluated no matter what. And today it is vague and baseless, a speculation. We're seeing a lot of speculations around black holes, most of them obviously turn out wrong.
    - witty_username 11y ago
      Your theory doesn't make much sense. There's really nothing special about "normal" matter vs antimatter. You could as easily call the matter I'm made of antimatter and reverse the names and the physics is the same for both.
      - lern_too_spel 11y ago
        You've set up a strawman. The GP doesn't claim that there's anything special about antimatter. He simply provides a wacky explanation for the unsolved problem of baryon asymmetry.
        Qwertious 11y ago
        The question is: Why would the black holes swallow up more antimatter than matter, if everything is completely symmetrical?
  - ubernostrum 11y ago
    There is actually a reason to care about black holes and information loss: no information loss is a consequence of assumptions baked in to how we do a lot of physics, so if information truly is lost that has consequences beyond just "how a black hole works".
- marcosdumay 11y ago
  The fact that some very smart people are on this debate should hint you that it's something more than this. But still, that's a perfectly valid oppinion. It may well be that entropy decreases as matter gets into a black hole. People just expect otherwise.
- aabbccdd 11y ago
  Then you might consider Thunderbolts Project worth of looking at: https://www.youtube.com/user/ThunderboltsProject https://www.youtube.com/user/ThunderboltsProject It's about ongoing explorations of the Electric Universe theory.
PuffinBlue 11y ago
Basing this on personal hunch instead of any theoretical hard standing whatsoever I think black holes are really just the event horizon, there's nothing 'inside' the event horizon. I believe that the collapse into a 'black hole' 'stops' at the moment that space-time curvature creates a sphere of space-time that geometrically appears to us 'outsiders' as the surface of a sphere or a shell - ergo the event horizon. That is, I believe that there is _nothing_ inside the event horizon (literally nothing, no space-time, no anything), the event horizon is just the region of space-time occupying the surface of a shell inside which there is NOTHING. I don't believe you fall 'through' the event horizon, I think that the matter that would otherwise make up the singularity at the centre of the black hole is smeared over this surface/event-horizon region. There are problems with this idea, but those are somewhat related to the fact we believe matter becomes infinitely dense (why wouldn't material on the surface of the sphere collapse to smaller spheres/event-horizons of their own) But infinite density is clearly not a 'proven' theory, however widely it's postulated - so we clearly don't understand if that is even a physical possibility. I've not seen anything concrete that says you can't model a black-hole as a shell of mass. As I understand it, to an outside observer a shell behaves gravitationally identically to a point mass at the centre of such a shell would. Of course, I'm no doubt very wrong, but whenever I've mentioned this to anyone, no one has really come up with anything to say it absolutely isn't possible, not without holding on to other things we 'think' we know like matter 'should' continue to collapse to infinite density once past some arbitrary point. Something I'm not convinced is true.
- privong 11y ago
  > I've not seen anything concrete that says you can't model a black-hole as a shell of mass. As I understand it, to an outside observer a shell behaves gravitationally identically to a point mass at the centre of such a shell would. > Of course, I'm no doubt very wrong, but whenever I've mentioned this to anyone, no one has really come up with anything to say it absolutely isn't possible, not without holding on to other things we 'think' we know like matter 'should' continue to collapse to infinite density once past some arbitrary point. Something I'm not convinced is true. Sure, you can model the external gravitational field as a shell of mass (interior to the event horizon), but they you have to explain why the mass is in a shell, rather than collapsing in on itself. If black holes form as the remnant of the cores of massive stars, then there's no shell configuration to start out with, so now you also have to explain why a shell forms in addition to it is maintained. So, while the shell model may be consistent with the external gravitational field, it seems to be constructed in an ad hoc fashion. Also, not everyone thinks matter should collapse to infinite density, e.g., [0]. I don't have enough domain knowledge to say how reasonable that particular model is. But "collapsing to infinite density" is a simple explanation for non-experts, but I don't think physicists are comfortable with it as an actual interpretation. The more common interpretation is that the laws of physics we have do not apply in such situations, and we need an understanding of quantum gravity to say what happens at the center of a black hole. [0] http://arxiv.org/abs/gr-qc/0506111 http://arxiv.org/abs/gr-qc/0506111
amelius 11y ago
I've always been told that the laws of physics are reversible, so I don't think information can be trapped anyway.
- JoeAltmaier 11y ago
  That's precisely the bit that is at issue. The boundary of a black hole seems to be asymmetric regarding information and the arrow of time. Not reversible, which would be a new thing.
  - SilasX 11y ago
    Stupid question: is this any differen from the "everyday" problem of information loss? That is, we know phase space is conserved, and yet, if you burn a piece of paper and mix up the ashes, you can't practically recover what was written on it. Is there information loss (per the claim in the dispute) in a stronger sense for black holes? Is it a case where multiple start states map to the same final state, or just another case of in-practice irreversibility like in the burning paper example?
    - akiselev 11y ago
      I am not a physicist but I believe it is similar in a superficial way. With a piece of parchment, the information is encoded based on the relative positions of molecules of ink and paper and if you use thermodynamically irreversible processes to decompose the constituent molecules you by definition lose any information encoded in higher layers of abstraction. The most fundamental piece of information is the identity of individual clumps of energy (subatomic particles). The reason black holes destroy information is that they are such an extreme environment that this identity no longer holds. Any energy, whether it is a photon or gluons making up a proton, that enters a black hole becomes a faceless part of the entire mass. Even if Hawking is correct and blackholes can radiate energy, anything they radiate will be made up of the same energy as the particles absorbed by the singularity but any information about what energy was before is entirely lost, as is any information stored in higher level patterns of that energy.
    - 11y ago
Thiz 11y ago
I've always thought they're not really holes but black spheres that absorb everything close to them including light.
- lukifer 11y ago
  The thing to remember is that space isn't flat. Gravity warps it, like a bowling ball warps a flat bed sheet, but in 3 (technically, 4) dimensions. A black hole is a warping where instead of a gradual dip in the sheet, there is a cone that plummets down seemingly infinitely. But the principle of relativity means we don't really know what's on the other side; just that anything that goes over the edge of the quasi-spheroid line (the event horizon) can't ever go fast enough to come back.
  - Thiz 11y ago
    I like my black sphere theory better, but interesting the similarity with a cone nonetheless.

37 points by bootload 11y ago

I find this black hole information debate akin to medieval ramblings on amount of angels dancing on diamond pin head. Can we please move on a little and come back when we have new angle?

mojuba 11y ago
Exactly. I call it exploitation of the unknown. You can generate lots of "theories" by just combining a couple of mysterious things into one. For example, something that hasn't been tried yet afaict, is a theory that black holes are a gateway between the physical world and human consciousness (or self-awareness).
- LoSboccacc 11y ago
  Oh i like the what if games. Black hole (as singularities that may have formed without collapsing stars) played a central role in early universe by swallowing matter and anti matter and radiating energy by hawking radiation which then fueled energy decay into standard matter, and that may explain the current imbalance between matter and anti matter or it may be mad internet rambling. Still medium worthy?
  - guard-of-terra 11y ago
    Your theory is so important that it will get evaluated no matter what. And today it is vague and baseless, a speculation. We're seeing a lot of speculations around black holes, most of them obviously turn out wrong.
  - witty_username 11y ago
    Your theory doesn't make much sense. There's really nothing special about "normal" matter vs antimatter. You could as easily call the matter I'm made of antimatter and reverse the names and the physics is the same for both.
    - lern_too_spel 11y ago
      You've set up a strawman. The GP doesn't claim that there's anything special about antimatter. He simply provides a wacky explanation for the unsolved problem of baryon asymmetry.
      - Qwertious 11y ago
        The question is: Why would the black holes swallow up more antimatter than matter, if everything is completely symmetrical?
- ubernostrum 11y ago
  There is actually a reason to care about black holes and information loss: no information loss is a consequence of assumptions baked in to how we do a lot of physics, so if information truly is lost that has consequences beyond just "how a black hole works".
marcosdumay 11y ago
The fact that some very smart people are on this debate should hint you that it's something more than this. But still, that's a perfectly valid oppinion. It may well be that entropy decreases as matter gets into a black hole. People just expect otherwise.
aabbccdd 11y ago
Then you might consider Thunderbolts Project worth of looking at: https://www.youtube.com/user/ThunderboltsProject https://www.youtube.com/user/ThunderboltsProject It's about ongoing explorations of the Electric Universe theory.

PuffinBlue 11y ago

Basing this on personal hunch instead of any theoretical hard standing whatsoever I think black holes are really just the event horizon, there's nothing 'inside' the event horizon. I believe that the collapse into a 'black hole' 'stops' at the moment that space-time curvature creates a sphere of space-time that geometrically appears to us 'outsiders' as the surface of a sphere or a shell - ergo the event horizon. That is, I believe that there is _nothing_ inside the event horizon (literally nothing, no space-time, no anything), the event horizon is just the region of space-time occupying the surface of a shell inside which there is NOTHING. I don't believe you fall 'through' the event horizon, I think that the matter that would otherwise make up the singularity at the centre of the black hole is smeared over this surface/event-horizon region. There are problems with this idea, but those are somewhat related to the fact we believe matter becomes infinitely dense (why wouldn't material on the surface of the sphere collapse to smaller spheres/event-horizons of their own) But infinite density is clearly not a 'proven' theory, however widely it's postulated - so we clearly don't understand if that is even a physical possibility. I've not seen anything concrete that says you can't model a black-hole as a shell of mass. As I understand it, to an outside observer a shell behaves gravitationally identically to a point mass at the centre of such a shell would. Of course, I'm no doubt very wrong, but whenever I've mentioned this to anyone, no one has really come up with anything to say it absolutely isn't possible, not without holding on to other things we 'think' we know like matter 'should' continue to collapse to infinite density once past some arbitrary point. Something I'm not convinced is true.

privong 11y ago
> I've not seen anything concrete that says you can't model a black-hole as a shell of mass. As I understand it, to an outside observer a shell behaves gravitationally identically to a point mass at the centre of such a shell would. > Of course, I'm no doubt very wrong, but whenever I've mentioned this to anyone, no one has really come up with anything to say it absolutely isn't possible, not without holding on to other things we 'think' we know like matter 'should' continue to collapse to infinite density once past some arbitrary point. Something I'm not convinced is true. Sure, you can model the external gravitational field as a shell of mass (interior to the event horizon), but they you have to explain why the mass is in a shell, rather than collapsing in on itself. If black holes form as the remnant of the cores of massive stars, then there's no shell configuration to start out with, so now you also have to explain why a shell forms in addition to it is maintained. So, while the shell model may be consistent with the external gravitational field, it seems to be constructed in an ad hoc fashion. Also, not everyone thinks matter should collapse to infinite density, e.g., [0]. I don't have enough domain knowledge to say how reasonable that particular model is. But "collapsing to infinite density" is a simple explanation for non-experts, but I don't think physicists are comfortable with it as an actual interpretation. The more common interpretation is that the laws of physics we have do not apply in such situations, and we need an understanding of quantum gravity to say what happens at the center of a black hole. [0] http://arxiv.org/abs/gr-qc/0506111 http://arxiv.org/abs/gr-qc/0506111

amelius 11y ago

I've always been told that the laws of physics are reversible, so I don't think information can be trapped anyway.

JoeAltmaier 11y ago
That's precisely the bit that is at issue. The boundary of a black hole seems to be asymmetric regarding information and the arrow of time. Not reversible, which would be a new thing.
- SilasX 11y ago
  Stupid question: is this any differen from the "everyday" problem of information loss? That is, we know phase space is conserved, and yet, if you burn a piece of paper and mix up the ashes, you can't practically recover what was written on it. Is there information loss (per the claim in the dispute) in a stronger sense for black holes? Is it a case where multiple start states map to the same final state, or just another case of in-practice irreversibility like in the burning paper example?
  - akiselev 11y ago
    I am not a physicist but I believe it is similar in a superficial way. With a piece of parchment, the information is encoded based on the relative positions of molecules of ink and paper and if you use thermodynamically irreversible processes to decompose the constituent molecules you by definition lose any information encoded in higher layers of abstraction. The most fundamental piece of information is the identity of individual clumps of energy (subatomic particles). The reason black holes destroy information is that they are such an extreme environment that this identity no longer holds. Any energy, whether it is a photon or gluons making up a proton, that enters a black hole becomes a faceless part of the entire mass. Even if Hawking is correct and blackholes can radiate energy, anything they radiate will be made up of the same energy as the particles absorbed by the singularity but any information about what energy was before is entirely lost, as is any information stored in higher level patterns of that energy.
  - 11y ago

Thiz 11y ago

I've always thought they're not really holes but black spheres that absorb everything close to them including light.

lukifer 11y ago
The thing to remember is that space isn't flat. Gravity warps it, like a bowling ball warps a flat bed sheet, but in 3 (technically, 4) dimensions. A black hole is a warping where instead of a gradual dip in the sheet, there is a cone that plummets down seemingly infinitely. But the principle of relativity means we don't really know what's on the other side; just that anything that goes over the edge of the quasi-spheroid line (the event horizon) can't ever go fast enough to come back.
- Thiz 11y ago
  I like my black sphere theory better, but interesting the similarity with a cone nonetheless.