No, you really don't. You say "multiverse" when (and it took some time to sort this out) you really mean "eternal inflation".I understand the concepts that have been proffered
Not so much as you think. She's more famous as a blogger. In the last five years her papers have received 75 citations, of which 10 were self citations. To compare, I am not even a theorist, but have written a couple of theory papers. The least-cited single paper of mine has 115 cites, of which 3 are self-cites.I believe Sabine Hossenfelder is a highly respected physicist - don't shoot the messenger!
So you don't understand the concepts. Understanding concepts (especially when it comes to such and advanced topics like the ones you try to discuss) means mainly understanding the maths behind them.I understand the concepts that have been proffered but not the mathematics that supports them.
Of course not, but that is not what you were initially asking. You asked some questions, got some lengthy replies pointing out your misunderstanings, and then you ignored it, restated again your wrong understanding as if nothing happened and then changed the subject. Is that a way to learn? Is that a way to discuss?Q1 Is there any evidence that there is more than one universe?
You'll note that you were asked several times for a reference to which model you were talking about, precisely because we didn't know which one you wanted to know about. That you don't seem to know which one it is and are unwilling to provide a reference to whatever you've been reading so that we can find out for ourselves is a huge part of the reason you are running into resistance - you aren't helping us to help you.If one of my learners asks me a question I try to check that I understand what it is they actually want to know then I try and answer to the best of my ability.
I think you have this backwards, basically. Anything we can see is part of the universe, by definition. If you want to posit other universes, then, they must be regions that are somehow disjoint from our universe. My understanding is that different models achieve that in different ways. Eternal inflation, which V50 thinks is the model you are talking about, achieves it (if I understand correctly) by having the spaces between bubble universes growing faster than the bubble universes. Bubble universes cannot form inside others because the interiors of the bubbles are true vacuum not false vacuum and can never overlap if they don't overlap initially, so we can never see another universe.I would like to know why we do not see any evidence of other universes.
Then you need to go learn the math. Consulting a cosmology textbook (Liddle seems to be a good one) would be a good start.I understand the concepts that have been proffered but not the mathematics that supports them.
Since you admit you don't understand the math, you have no valid basis on which to either accept or to not accept what I said. What you should be doing is learning the math, so you can make a valid judgment.PeterDonis tells me that space within our own universe is a complete vacuum (which I did not accept)
Which is perfectly consistent with what I said about empty space in our present universe. Go read what I said in post #8 again about the empty space in our current universe. Notice the word "fields" in it, and what I said about them.then I am told that everywhere in our universe if full of the fundamental fields
You can't eliminate hypotheses by way of reason alone unless they are logically inconsistent. Multiverse theories are not. You might not like them (and you would find plenty of physicists to agree with you), but you can't rule them out on purely logical grounds. That's why criticisms of such hypotheses by physicists don't attempt to rule them out on logical grounds; they criticize them based on lack of evidence.What I am seeking to do is eliminate the Multiverse theories from my cosmological enquires by way of reason.
You've already said you don't understand the math involved, and without that you won't be able to understand anything we have said in this thread in response to your questions. So, as I said in my previous post, you need to go learn the math.Can anyone point me to an explanation given here that might help me understand?