Well, againa good example of why believing and assuming is not knowing.
You misunderstand me. I never said I believed in any of this, and have never asserted that any of it is in fact true. Nobody knows whether any of this is true, least of all those who have propounded such theories. What I said was, I'm of the opinion that the balance of the evidence at present points in the direction of extra dimensions and/or parallel universes, and if this turns out to be true, it might end up explaining some of what we call "paranormal phenomena" these days.
It may turn out that we just don't yet know enough to realize these things aren't necessary to explain the observable universe. Maybe future observations will turn up a more mundane answer. Only time will tell. But either way, the main point of all this is that we don't at present really KNOW how the universe works. Yes, we have a pretty solid understanding of many aspects of it, but there are still large blank areas on the map, so to speak, and some of these unknowns are at a pretty fundamental level.
My point in bringing all this up was merely to point out that over time, improved science has been able to explain and predict more and more phenomena that were once regarded as supernatural. And it's possible that, if parallel universes and/or extra dimensions are shown to exist, they will show that various superstitions involving spirits are based on people just observing some normal, scientifically explanable physical process.
Extra dimensions to the 3/4/6/8/12 (How many dimensions we know depends on who you ask. Parallel universes on the other hand, are complete fictional currently ...
I believe you to be misinformed. There seems at least as much evidence for parallel universes as there is for extra dimensions. At present, both appear to be equally valid alternative explanations for various problematic observations. As you point out, however, the current state of knowledge is far from perfect--not only is there disagreement on these alternatives, but also on the number and type of their component parts. But the sheer amount of effort spent on these subjects (by legit scientists who publish in peer-reviewed legit journals) is indicative of the perceived need for one or the other explanation within the scientific community. If the currently accepted theories explained everything, there'd be no need to invoke anything as weird as extra dimensions or parallel universes.
Same with dark matter. Do you
know, as you have defined that word, that it exists? If so, can you tell me how much of the mass in the universe is dark matter? If not, what alternative mechanism do you offer to explain observed gravitational effects at galactic scales? At present, it appears that dark matter is the generally accepted explanation for large-scale gravitational effects, but there is great disagreement on how much of it there is. I've read papers this year that have dark matter ranging from 50% to 90% of all mass.
But even given the general acceptance, nobody's yet made any direct observation of dark matter. They've got all these gizmos buried in deep holes but they've turned up nothing definitive (or much of anything, really). All the dark matter proponents have to go on is the indirect evidence of observations that can't be explained by Newton or Einstein, but can be explained by invoking dark matter. Problem is, the dark matter theory doesn't explain all such problematic observations. OTOH, MoND seems to be at least as good an explanation as dark matter, although it can't explain all observations, either. Neither one seems to be the real answer, at least in their current forms. The real answer might end up being something completely different from either. Only time will tell.
Personally, I like to keep Ockham's Razor sharp. As such, I'd much rather see MoND win than dark matter, because MoND doesn't require some strange, indetectable substance to make up the bulk of the universe. Dark matter reminds me very much of the old "luminepherous ether". But if dark matter wins in the end (as it very nearly has, given the proportion of scientists who accept it), oh well. If that's how those in a real position to know conclude the universe works, then who am I to say otherwise?
I'm really the same way about parallel universes and extra dimensions. I'd much rather that neither existed. Things get REALLY weird when you go that way. But I'm open-minded enough to accept that one or the other, or both, might really exist, and can see why many legitimate scientists seriously propose them as rational explanations of how the universe works.
The only good thing I can see coming from proving parallel universes exist is the consternation this would cause theologians :rofl:. Think about it. If a religion relies on making the "right" choices via free will to obtain salvation, parallel universes would really undermine its position. Every possible outcome of any choice would be embodied in a full-blown separate universe, and these themselves would fork as later choices come up. Where is free will if the answer to every question is "all of the above"? And the diety's judgments between the saved and the damned would be purely arbitrary, because everybody would both meet and fail the criteria they've been told make the difference. Watching this play out in theological discussions would be worth the weirdness the parallel universes would cause for more mundane concerns

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It is simple to believe in things... and much harder to know.
All I believe is that we don't
know very much about the universe's inner workings. We know a lot, no argument, but it's mostly about stuff that we interact with fairly regularly. As to the fundamental nature of the universe, OTOH, we're pretty ignorant. If we really
knew the nature of the universe, we'd have a unified theory instead of separate theories for the very large and very small scales. And as pointed out all through this discussion, the separate theories we do have need improvement because they can't explain everything that happens in their own realms, let alone each other's.
So, until the day that we have a single "theory of everything", I will maintain that despite all we know about things of practical value and everyday utility, we know very little about the nature of the universe itself. And if quantum physics is anything to go on, I gloomily predict that if I live to see a "theory of everything", it will have to contain some pretty weird stuff.