https://en.wikipedia.org/wiki/List_of_most_massive_black_hol... shows the maximal theoretical limit as 270B solar masses.
> [270B solar masses] is the maximum mass of a black hole that models predict, at least for luminous accreting SMBHs.
as well as:
> The limit is only 5×10^10 M [50B solar masses] for black holes with typical properties, but can reach 2.7×10^11 M [270B solar masses] at maximal prograde spin (a = 1).
However in the chapter before, it's stated:
> New discoveries suggest that many black holes, dubbed 'stupendously large', may exceed 100 billion or even 1 trillion M.
For everyone else reading the thread, let me summarize. The article agrees with me:
> the entire observable universe exists within a black hole—except, that is, for all the evidence to the contrary
>....
> It does not seem likely that we live inside a rotating universe, let alone a black hole.
(I'm not thinking this is too much to ask; saying it's wrong might require empirical support, but the claim that it's "nonsense" should be easier to justify.)
It really looks nothing like a black hole.
I mean, everything in our universe does move towards something. The future.
As another comment pointed out, in GR our "future" is a singularity which everything moves towards (so what we see as a time dimension).
"Expanding" and "contracting" depend on your coordinate system. If your rulers are shrinking, you can't tell this from space expanding.
The common factor here is you are wanting to use our reference frame (somewhere in this universe, not near a black hole) to describe things as they would be seen from other reference frames.
How would we know the size? Relative to what?
https://scitechdaily.com/cosmic-heavyweights-collide-ligo-de...
https://www.youtube.com/watch?v=doS85Mh78Vc
This is what they look like when they merge, its pretty darn cool