Black holes aren't really black holes
- Thread starter K.I.L.E.R
- Start date
*nods, pretends to understand and slowly backs away*
heh, amazing era of information we live in isn't it.
The_Wolf_Who_Cried_Boy
Newcomer
So in what state does the matter exists as it patiently awaites evaporation as Hawking radiation. I thought the whole idea was local gravity was more than enough to overwhelm repulsion from the exculsion prinicpal. What's "keeping it up"? Turtles presumably.
There really is no distinction at that level of gravity. All the matter gets compressed into a singular point. Its not in any classical state of matter like gas, plasma, solid, or liquid. Hawking radiation has to do with information being transferred at the event horizon between particles and their virtual analogs. It gets a bit complicated at that point. Basically, virtual particle-antiparticle pairs are everywhere, but usually annihilate themselves. Imaging a virtual particle pair that is created at the "edge" of the event horizon. Every so often one of the virtual particles will get sucked into the event horizon, while the other stays outside of the event horizon. At that point, the virtual particle becomes "real" and information is lost from the system. Virtual particles are quite strange and interesting. One of the weird things is that the virtual particle getting sucked into the black hole has negative energy to an observer at a distance (Schultz). Weird stuff.
Think about it logically though. If black holes gain size by accruing matter, why isn't the universe in the process of being swallowed by huge wandering black holes?
Last edited by a moderator:
The_Wolf_Who_Cried_Boy
Newcomer
Kruno's post was suggesting that this actually doesn't happen, or happen completely. So if it isn't crushed into a singularity, what properties does it still have?
Here's the article.
http://science.slashdot.org/article.pl?sid=07/06/20/1833246
http://science.slashdot.org/article.pl?sid=07/06/20/1833246
1. First of all, it looks like the underlying research has nothing whatsoever to do with the black hole information paradox. We are unlikely to be able to be confident we have the answer to that before we have a fully quantum theory of gravity.
2. We've expected for a long time that no singularity would form in a black hole. Physical singularities are typically considered to be artifacts in the theory, instead of actual entities.
3. The energy density of a singularity would far exceed the Planck scale, and as such we could not use General Relativity, which we expect to break down at the Planck scale, as an appropriate theory to describe the singularity, if it exists. Since General Relativity is the theory used to predict the singularity in the first place, we have no reason to expect a singularity in a black hole.
And finally:
4. The relevant component of a black hole is the horizon, not the singularity. Irrespective of what goes on inside the black hole, the horizon itself seems to be well-understood.
2. We've expected for a long time that no singularity would form in a black hole. Physical singularities are typically considered to be artifacts in the theory, instead of actual entities.
3. The energy density of a singularity would far exceed the Planck scale, and as such we could not use General Relativity, which we expect to break down at the Planck scale, as an appropriate theory to describe the singularity, if it exists. Since General Relativity is the theory used to predict the singularity in the first place, we have no reason to expect a singularity in a black hole.
And finally:
4. The relevant component of a black hole is the horizon, not the singularity. Irrespective of what goes on inside the black hole, the horizon itself seems to be well-understood.
You mean, "postulated to be well understood", as we've never actually been able to perform any experiments on one to prove or disprove our collective understanding.
There are, however, quite good theoretical reasons to believe that GR does not break down at the event horizon. I have to admit that I'm not up to date on the latest experimental evidence for the existence of black holes, but the event horizon itself it highly likely to be accurate, given current tests of GR and the nature of the prediction.
Thank you for insulting my field of study.
Yeah, you know basically nothing at all about science.
If that we're true, you wouldn't be typing on the computer you're using today, nor using GPS for geo-location or mapping services.
What your post shows is that many people, even perhaps upper-middle class people who are educated and use computers and technology, don't understand science.
Most scientists are rather skeptical of this paper, for a number of reasons.
The BH information paradox is solved in a number of specific cases (usually extremal configurations or say in the AdS sense), but remains open in quite a few general areas, despite the wide ranging belief that it will be solved really soon.
The BH information paradox is solved in a number of specific cases (usually extremal configurations or say in the AdS sense), but remains open in quite a few general areas, despite the wide ranging belief that it will be solved really soon.
The (mis)understanding of what science is always shocks me. Were people not taught the fundamentals of what science is and isn't in school? I recall distinctly being taught what sciences goal's were and what they were naught. Instead science is pushed as the "answer" when that's the opposite of what it is!
"quite good theoretical reasons". But not validated ones.
Believe it or not, cosmology and astrophysics have been becoming quite exact over the past decade. The basic theoretical issue that I was speaking of is that the tidal force at the event horizon of larger black holes is quite negligible, and as a result we would not expect to see a breakdown of GR there. I rather expect that measurements of binary pulsars are enough to very tightly constrain our possible misunderstanding of what is going on at the event horizon, at least for very massive black holes.
There still is a lot that we don't understand about black holes that are just a couple of stellar masses, but just give it time.
I guess I'll just have to not believe the level of exactness you describe. When something is unmeasurable, the best you can do is lay out a framework that fits the few observable points you have, then hope (or believe) you're correct until another data point comes up that breaks your framework. If one never shows up, it doesn't mean you're correct.
For something that is inherently unmeasurable, well, you know the arguments about that.
For something that is inherently unmeasurable, well, you know the arguments about that.
