I Universe Inside Black Hole: Principles Different?

[exponent137]

I read somewhere that it is not possible to prove that Our universe (from big bang to now) have different principles that inside of black hole. I think that one physicist said something like this.

Or in different words: are principles of our universe different as inside of a black hole?

 

[Ibix]

You really need to provide references for this kind of claim. It's hard to know what someone or other may or may not have said (or intended to say) somewhere.

On the face of it the claim is wrong. There are a lot of differences between a black hole interior and the universe at large. Notably that we haven't smashed into the singularity or been torn apart by tidal forces.

That said, the local structure of spacetime is the same inside a black hole as outside. It's just that the plausible definition of "local" is radically different (very small, and getting smaller) and the local patches fit together differently. So in a closed box you can't tell whether or not you are inside a black hole. But we aren't in a closed box.

 

[Khashishi]

The universe is expanding, not shrinking. So how could it be black hole?

 

[PeterDonis]

I read somewhere

As @Ibix said, please provide a specific reference. We can't discuss vague recollections.

 

[exponent137]

I Forget reference. But now I looked SCI channel and saw a commercial for series "How the universe works" and one said almost so as I wrote. (universe is like ...inside of black hole) I will try to find this citation. I think that I find this citation also elsewhere, maybe Matt Sutter said this, but, as I read some links of him, I did not find such claims.

I will try to find this reference on SCI.

 

[exponent137]

This is where I looked this:

after 5:43 this citation happens. (This is also on SCI channel.)

What is your opinion, or where I can find additional information about this?

 

[Ibix]

I find that video very confusing. Some of it is just plain wrong (the singularity in a black hole isn't an infinitely dense point, for example). Some of it has to have been taken out of context if it's not wrong (the stuff about Planck units being the smallest units of space and time isn't true in relativity; maybe it has meaning in some quantum theory of gravity - I don't know). So by the time I get to your timestamp, I've been saying "no", "not really", "maybe", or "that's an enormous over-simplification" about every ten seconds for nearly six minutes. Just to set the scene.

The bit you are talking about isn't talking about GR, anyway. The video doesn't seem to be clear about whether it means that a universe exists inside a black hole, or if the not-quite-singularity eventually forms another universe, or if this kind of causal language doesn't really describe this kind of thing (both the first two wordings pop up - the third is my own suspiscion). It does say "speculative" at least twice.

So my answer is that I don't know any more having watched this video than I did before. It doesn't provide references and doesn't provide a consistent model that one can consider. The claim is still flat wrong in general relativity. We don't know which, if any, of the successor theories that we have is correct, so it would go under "not impossible" for now.

I believe that Lee Smolin proposed something of the sort of thing they are talking about. I don't know any more than that, but following up on work Smolin did might be a start.

 

[PeroK]

This is where I looked this:

after 5:43 this citation happens. (This is also on SCI channel.)

What is your opinion, or where I can find additional information about this?

At 1:45 there is a woman stating unequivocally that time and space are quantised (and that is what Quantum Mechanics means!). Which is plain wrong. Everything from 5:43 is wild speculation.

Strangely, you have Max Tegmark saying you can postulate any number of new kinds of matter and say "suppose this kind of weird stuff exists ... but the problem is that there is no evidence that this stuff exists". Which undermines the nonsense in the rest of the video. Perhaps the people who made the video didn't notice this.

The fundamental point, however, is that this is entertainment and not science, so you can't really have a scientific discussion about it.

 

[stevendaryl]

I read somewhere that it is not possible to prove that Our universe (from big bang to now) have different principles that inside of black hole. I think that one physicist said something like this.

Or in different words: are principles of our universe different as inside of a black hole?

There is a fairly definitive discussion about the question here:

http://math.ucr.edu/home/baez/physics/Relativity/BlackHoles/universe.html

 

[kent davidge]

"suppose this kind of weird stuff exists ... but the problem is that there is no evidence that this stuff exists". Which undermines the nonsense

I would like to ask in what sense supposing something not confirmed exists in order to initiate a discussion is non sensical? (I'm really just asking).

 

[PeroK]

I would like to ask in what sense supposing something not confirmed exists in order to initiate a discussion is non sensical? (I'm really just asking).

I meant nonsense more in the sense of naughty children misbehaving!