Re: Another silly question...
No, of course this universe isn't the only universe, there is no mechanism to stop the same thing happening twice (can you even hypothesize how such a mechanism would work?), so of course it would keep happening. Just like everything else does in science, experiments are repeatable because they repeat!
Nor is it cyclical, there is nothing to stop the same thing creating a second universe *while* a first universe exists, there is no 'one-at-a-time' lock mechanism possible either. i.e. it is not that this one off thing does a repeating cycle, but yet is still blocked so it is one off.
So time and space existed, and this universe isn't everything. Its not the one and only universe, whether a sequential / cyclical one-and-only universe or otherwise.
And black holes of course are not the end of stuff. It isn't that matter falls into a black hole, gets super compressed and super hot and can never escape. Because that would create a dead-end. Since time existed before the start of the universe, there is infinite time, and given infinite time everything would be in stuck a black hole.
The motion of heat alone inside the black hole would mean it would be constantly falling inwards to an infinitely stretching space, because it cannot move outwards.
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So, ideally, I'd like them to find two black holes near galaxies, in a configuration that shows the black holes attract each other strongly and the attraction between galaxy and black hole is far weaker[1].
Given the above, consider that inside a black hole other black holes can form. That as more black holes form inside the outer black hole, so the gravity weakens (due to [1]), thus that continues till the outer black hole can no longer sustain its >c pull and collapses inwards spewing its contents out. i.e. spiral galaxy formation is the result of the black hole collapse.
You assume the black hole at the center of a galaxy is sucking in the matter of the black hole, forming some spiral structure somehow. But you should consider the rather obvious above scenario. That black holes can form inside the stretch space of a black hole.
You can also show the above (galaxy creation model), by finding a correlation between new stars and the centers of each galaxy. The older stars were ejected first and so should be further out.
And of course, what does a black hole look like on the inside? It has a visible boundary at the event horizon, and contains black holes... 'heat' is just motion over space, and if space is stretch then heat is lower, i.e. it is cold but cannot be zero.
Where have I seen that before? Yep, our universe is like that. Non zero background heat which should have an orientation.
If our black hole is shrinking, are we losing galaxies? That would be another observation which would point to us being inside a black hole. Because if black holes inside are ejecting matter, then so should our outer black hole, and so we should see galaxies vanishing.