The interesting question is, given that it appears that space-time is ‘something

The interesting question is, given that it appears that space-time is ‘something’, and that particles are products of space time, then what causes the density of the original collapse?

If we understand the expansion(explosion), then what is the cause of the contraction(collapse)? I mean, would buy the un-experience-able alternate (or invisible) universe theory if the ‘cold’ or ‘dark’ matter was offset by the hot and light matter, and that the cold matter will ‘take over’ from the hot matter and cause the collapse.

That would make sense to me. that explains black holes and dark matter. This whole ‘dimensions’ thing is merely a way of thinking about that equilibrium then I’m ok with it. If there is some other ‘universe’ I just …. that seems like a common cognitive bias or error that humans get in the bad habit of using: duplicating a story that you don’t understand rather than simplifying the story by solving what you don’t understand.

Again. I am not so much looking at any particular evidence other than that humans demonstrate a consistent set of biases, and scientific discoveries a consistent set of ‘refutations of biases’.

And so if I simply look at what we do see in physics, and apply parsimony to the theories, and discount the usual biases, then the simple answer is more likely in the simple direction than any other.