I love multiverse theory! I also love how a lot of people don't really understand how finite infinites work in the context of multiverse theory!

There might be a universe in which magic exists. However, there is no universe in which I exist and magic exists. That's because I was born into a mundane version of the universe, so there are infinite possibilities, but because my existence in a magical universe is 0, being accepted into a witching school is something that'll never happen for me.

So no, within the context of multiverse theory there is no universe in which multiverse theory doesn't exist, because that is a paradox and as such, has 0 chance of existing. However, it totally possible that a magical universe does exist (I would say we don't know enough about the formation of the universe to accurately judge whether or not such a universe could be possible under the right formative circumstances); it's just that the chances of any of us existing in that universe is 0.

You're getting into omniverse territory here, I think. But if accurate, then the dimensions without multiverses just lack the ability to perceive, observe, understand, measure, prove, or travel outside of their own universes. There's a whole multiverse of such isolated bubbles that will "know" that there's no multiverse, and we have a 50/50 chance of being in one.

Or, the conjecture of the multiverse, being non falsifiable, makes it as scientific as the boogie man or the tooth fairy. God of the gaps anyone?

One night I was thinking about multiverse stuff and I wondered if you could cause a paradox in another timeline. I got stuck on thinking that it might not immediately destroy the timeline and then I began to worry what it would be like if we lived there. (I was not sober lol.)

Group theory already solved that one 😄