Do Black Holes Create New Universes?

  • Thread starter Thread starter photon
  • Start date Start date
  • Tags Tags
    Black holes Holes
AI Thread Summary
The discussion revolves around the fate of matter in black holes and the concept of Hawking radiation. Participants explore whether matter is converted to energy and how it contributes to the curvature of space-time, with some suggesting that black holes might emit energy as Hawking radiation due to quantum effects near the event horizon. There is debate about whether matter ceases to exist in any form after crossing the event horizon and how this relates to the singularity. The conversation also touches on the implications of Kaluza-Klein Theory and the nature of vacuum energy in relation to gravity. Overall, the complexities of black holes and their interactions with quantum mechanics and general relativity are central to the discussion.
photon
Messages
125
Reaction score
0
I've been doing some writing in my physics journal about black holes and baby universes. I'm stuck with near nothing because of a lack of ideas. I have quite a few questions, but would like some other opinions on the matter.
What happens to the matter in a black hole after it has evaporated? I was thinking something like it all going to another universe like our own. (Even though I don't belong in the same universe as most people here. )
So, post away!
 
Physics news on Phys.org
Are you talking about this Hawking radiation?

I don't know very much about it, but I've gotten the impression that it is indicatrive of one of those situations where QM wins against GR. That is, the gravity won't even allow light to escape, classically, but the uncertainty allows for a finite probability of a trapped photon being found outside the black hole (a very "red" photon).

Another thing that I'm not sure about but have understood to be the case is that, when stuff (i.e. matter) gets trapped by the black hole, it no longer exists in our universe as matter, but it still contributes to the curvature of space-time in our univserse. So, I conclude from this (in a very simple-minded way) that the matter becomes energy, and that all the "stuff" in a black hole looks like energy to our universe. It is this energy (I conjecture) that fuels the Hawking radiation.
 
I'd always just assumed that any matter entering a black hole is spat into another time and or universe depending on it characteristics.
I'm leaning towards a definite relationship with Kaluza-Klein Theory here and his mention of a fifth dimension. It is in this dimension that the sieve/filter type processing of matter in the black hole determines how and where matter/energy is transferred to. Perhaps the Hawkins radiation is simply matter of the observable universe being ejected back into that same universe, i.e. not processed or transported within the black hole and which might include matter transported by the black holes dimensional twin.

I haven't fully got my head around how a black hole might treat matter at the subatomic level and whether atoms are pulled apart or if they remain stream like i.e. retain their topographical shape. I'm inclined to think at the very minimum that the topographical signature of any matter entering the black hole is not compromised. My reasoning behind this is that otherwise we would have far to many anomalies (a bit like the Fly film) and physics would not be able to maintain it's consistency. Just as a side note I suspect that a black hole can only be closed once it's corresponding piece of space-time (it's lid) enters into the black hole. This lid I suspect is unique in its topographical, dimensional nature and is the lid that allows our universe to shape shift and cross over into other dimensions when needed or appropriate. The big bang would be a good example of this phenomenon at work.

Silvershadow
 
Last edited:
Well i would also assume that the mass would be converted to energy and emitted... but then that leads to the problem that if light can't escape a black hole, how does any emissions? i know that black holes emit x-rays so that how we know where they are, but them thar waves must be very (as in EXTREMELY) energised. I am prob wrong then.
 
Originally posted by jimmy p
Well i would also assume that the mass would be converted to energy and emitted... but then that leads to the problem that if light can't escape a black hole, how does any emissions? i know that black holes emit x-rays so that how we know where they are, but them thar waves must be very (as in EXTREMELY) energised. I am prob wrong then.
Light can't escape from WITHIN the black hole's event horizon, but it can escape when it's very close (but outside) the event horizon.

The general description of Hawking radiation is that a virtual pair of particles is spontaneously created very close to the event horizon. One falls in, the other flies escapes. It is as if the black hole created the escaping particle, and thus evaporated.

- Warren
 
Originally posted by Ambitwistor
The matter or radiation ("energy") that falls into a black hole doesn't have to continue to exist in for the black hole itself to exist. So we don't know whether anything continues to exist in any form once it hits the singularity.
Doesn't there need to be stress-energy to curve space-time? Are you saying that, once space-time curves enough to make a black hole, that the curvature will support itself? That would be some new level of understanding for me. Also, I wasn't talking about the matter being at the singularity, just inside the event horizon. Would that make a difference?




Originally posted by Ambitwistor
Hawking radiation isn't produced by anything that fell into a black hole; it's a vacuum effect.
Does it happen here on earth? What are the requirements?
 
The general description of Hawking radiation is that a virtual pair of particles is spontaneously created very close to the event horizon. One falls in, the other flies escapes. It is as if the black hole created the escaping particle, and thus evaporated.
If I remember correctly, the particle that falls into the hole will have negative mass/energy causing the black hole to shrink. Both particles then become real particles because they can no longer turn into energy.
 
What are the properties of a singlarity?
 
Originally posted by Ambitwistor
No; there are plenty of curved solutions to the vacuum Einstein equations; the Schwarzschild solution is one of them.
I read on John Baez' website that GR shows that the vacuum has very close to zero energy.

I assumed that was because the vacuum is very close to being flat, and so there cannot be very much stress-energy in it, or else it would not be flat.

Am I jumping to the wrong conclusion? I know this is the other side of the coin, but that new revelation made me second-guess my assumption.
 
  • #10
Originally posted by Ambitwistor
Well, as you will also see on Baez's website, there are many different ways of speaking of the energy of the vacuum in quantum field theory.
Don't get deffensive, I'm just trying to resolve the conflict in my mind. I don't see why QFT should enter into the discussion.




Originally posted by Ambitwistor
It's not at all clear right now what relation the vacuum energy has to the curvature of spacetime: this is part of the famous cosmological constant problem.
So does GR just say that the vacuum has almost zero energy as a postulate? That doesn't seem right. From what in GR is almost zero vacuum energy concluded?
 
  • #11
Originally posted by Ambitwistor
In classical physics (not just GR), the vacuum never has energy: energy arises from particles, fields, etc. Vacuum energy is a quantum phenomenon.
I guess I need to get straight on what the vacuum is. I have been thinking of it as empty (absent of mass) space-time. I thought that, for instance, E&M radiation propogated through the vacuum, but that it was still vacuum. What do you have to say about this?
 
  • #12
Originally posted by Ambitwistor
general relativity is a nonlinear theory in which gravity gravitates.
OK, maybe you can straighten me out on this one. When I first say Einstein's equation (not too long ago, in case you haven't noticed), I thought that the nonlinearity was the diff. eq. being nonlinear in the sense that, if the metric is gμν, and Einstein's tensor is Gμν, then if the metric is Ag(1)μν + g(2)μν, then Einstein's tensor is not necessarily AG(1)μν + G(2)μν. Then, after some forum chat, I thought that I began to realize the nonlinearity was the fact that Rμν (or gμν, or something else related to the curvature) contributed to Tμν, in which case, Tμν would not be zero, even though there was no mass or energy from anything (other than the curvature), sort of like recursion. I am not at all clear why there is a contribution, though.
 
  • #13
Is there such a thing as an 'anti-black-hole'?
 
  • #14
Originally posted by Ambitwistor
I'm not sure in what sense the Riemann tensor can be said to contribute to the stress-energy tensor.
I had been given the impression that curving space-time was a lot like disturbing a system from its equilibrium point.

As an extremely simple example, I was trying to think about it like a spring. Flat space-time is like a spring neither compressed nor stretched. Curved space-time is like a spring either compressed or stretched. Then, there should be some energy associated with the curved space-time (at least with respect to the flat space-time).

In other words, I had the impression that empty space-time "wants" to be flat (like "a body in motion 'wants' to stay in motion..."), and that space-time with stress-energy in it curves just so under the influence of the stress-energy (like "unless there is an inhomogeneity").

Alright, so we're getting more specific: Is curved space-time at a higher energy than flat space-time, because it is curved?

Sorry, this stuff just takes a while to sink in (and I am paranoid of nuance).




Originally posted by Ambitwistor
You can have curved spacetimes that gravitate (such as the Schwarzschild solution), but the stress-energy tensor is everywhere zero.
Everywhere? Even at the singularity?
 

Similar threads

Back
Top