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Question:

There are mathematical proofs available for the Einstein-Rosen bridge. But I was wondering whether there is experimental proof for such a thing. The general theory of relativity supports the fact and thus allows us to think of existence of such a thing.But I don't think a concept which cannot be mathematically proved must be universally accepted.

Note:-

I am not questioning Einstein's theory of general relativity but the existence of such a point in space where matter goes into a singularity is what questions me.As far as I know universe is continuously expanding and existence of such a hypothetical and supporting it shouldn't be done unless it is somehow proved mathematically.

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  • $\begingroup$ The paper you cite has nothing to do with the Einstein-Rosen bridge. It discusses the Einstein-Podolsky-Rosen (EPR) paradox, which is completely different. $\endgroup$ – probably_someone Feb 12 '18 at 14:22
  • $\begingroup$ Sorry I am going to edit the post then. $\endgroup$ – user184590 Feb 12 '18 at 14:23
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    $\begingroup$ There are no experimental proofs of the Einstein-Rosen bridge that I know of. $\endgroup$ – probably_someone Feb 12 '18 at 14:25
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I think you got it exactly backwards. There are theoretical demonstrations of the Einstein-Rosen bridge, i.e. you can write down the Schwarzschild solution the Einstein field equations, do a couple changes of coordinates, and demonstrate the system contains a wormhole; see any general relativity textbook for this. There are of course no experimental demonstrations -- that would be sensational.

The other objection you have is that singularities should be impossible because the universe is expanding. This doesn't make sense on the scale of a black hole because the expansion of the universe is very weak; it's totally undetectable for anything short of cosmological scales.

On the other hand, it's a fair question why the universe has concentrated lumps of matter in it, such as galaxies and stars, when you would expect a uniform distribution. This is due to gravitational instability: matter attracts matter in a runaway process, so any inhomogeneities get amplified. Remarkably, this doesn't violate the second law of thermodynamics because lots of entropy is produced by gravitational potential energy going into kinetic energy during collapse. (I've heard some people go so far to say that's the fundamental reason life can exist at all, though it really depends on what you mean by 'fundamental'.)

Mathematically, once you have these concentrated lumps of matter you can prove sufficiently dense matter must form black holes, e.g. the TOV limit for neutron stars. Then the Penrose-Hawking singularity theorems essentially say that if gravity in a region is strong enough, such as in a black hole, there must be a singularity.

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  • $\begingroup$ Thanks.Can you edit my question to make it better.I think I have made some mistakes while writing it. $\endgroup$ – user184590 Feb 12 '18 at 14:41
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    $\begingroup$ It may be worth noting that Einstein-Rosen bridges are features of eternal black holes. You do not expect them in black holes formed from collapsing matter. $\endgroup$ – mmeent Feb 12 '18 at 15:02
  • $\begingroup$ Very interesting answer! Does this mean that all black holes contain a wormhole? $\endgroup$ – freecharly Feb 12 '18 at 15:21
  • $\begingroup$ @freecharly No, I should’ve clarified that. While black holes and singularities are generic, wormholes are not, as mentioned by a comment. $\endgroup$ – knzhou Feb 12 '18 at 16:20

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