Trying to Understand Many-Worlds Interpretation Better

[GrandizerII]

Alright, so I have some idea of how Many-Worlds interpretation works and why it's accepted by many top experts in the relevant fields as the most logical explanation (since it's seen as the most parsimonious and logical explanation for what goes on in the quantum world).

I, for one, do not accept this interpretation as true because I do not put such a high trust in our logic to explain bizarre things that go on in there, so I'm perfectly happy (for now) with the Copenhagen interpretation.

But what I'm interested here in this thread is what exactly does Many-Worlds interpretation imply if it is indeed true.

If MWI is true, does this mean that anything that is possible has 100% happened somewhere in at least one of the infinite parallel universes? Is it really possible that there is a "me" out there somewhere that has done the most heinous things that one could ever imagine?

Must quantum immortality logically follow from the truth of MWI? Are we really each an immortal character in our own universe?

What bizarre things on the macro level have been witnessed in this particular universe that we share (if we even do share the exact same universe) that may hint at the truth of MWI?

What does this tell us about the possibility of Christianity or other religions (or gods) being true? If they are impossible here, would they still be considered impossible in all the other universes no matter how many parallel universes there may be?

What does this tell us about the ability to predict anything in the future given that MWI is true?

Finally, how do you feel about MWI being possibly true?

[professor]

The Multi Universe was invented as another scheme to justify the belief that this place is not unique. Good luck on that one.

[Anomalocaris]

But what I'm interested here in this thread is what exactly does Many-Worlds interpretation imply if it is indeed true.

That is the fundamental problem with many worlds interpretation. It is an explanation that uniquely implies absolutely nothing that can be tested that the explainer would not have already known before he made the explanation.

In this MWI is as bad as Christianity.

The only thing that makes MWI, totally worthless as it is, still infinitely better than Christianity is it does not contradict what we do already know going in.

[GrandizerII]

The Multi Universe was invented as another scheme to justify the belief that this place is not unique. Good luck on that one.

Wrong thread, professor. This isn't referring to that other multiverse explanation (which I personally accept as true given some "dark" hints in this universe to its existence).

[Brian37]

Multiverse theory is not based on nothing. It can be flawed to the point where it can be discarded. But again, this is still a better way of prediction even if it does not pan out as true, because it is subject to real rigors of scientific method.

The good thing about ethical science is that you DO have competing theories but time will defeat one over another and with the rigors of peer review you keep what works, build upon that and discard what doesn't work.

It makes much more sense to extrapolate multiple universes just like a bubble bath. Not saying it is currently proven. But we also at one point thought our galaxy was the entire universe. It was at the time our best data, but because science refused to stop at that, we didn't discard the evidence of our galaxy and throw out all the data. We simply improved on the data and adapted the newer data.

Will a multiverse be proven? I think currently at best it will only be on paper. Other scientists dont buy it as a theory. However Just like we most likely, will never travel into a black hole. Mathematically we do know based on laws of nature to a great extent what happens to the material sucked into a black hole.

One big wall science has hit is detecting anything behind our background radiation. If we ever figure out a way to build a tool that can do that, I would say it would go a long way in knowing what happened prior to the big bang.

I would say if we are going to extrapolate something prior, we will not find a god. It would be more like a decayed leaf becoming nutrients for a future plant.

Cycles exist in everything so if you view the universe as a weather pattern, and not an invented product, what we don't currently know would be just as natural and cyclical as the seasons changing on the planet. If we find out, whatever we find out, will not include a sky hero. QM is actually really freaky in that it is pointing to both something or nothing prior. But what QM does not require is a cognition as a starting cause.

[Angrboda]

I'm just a layperson with no real knowledge of physics, but here's my understanding of it.

If MWI is true, does this mean that anything that is possible has 100% happened somewhere in at least one of the infinite parallel universes? Is it really possible that there is a "me" out there somewhere that has done the most heinous things that one could ever imagine?

According to my understanding, no. All possible worlds evolve according to the same wave function equations, so only those things for which there is a quantum mechanically consistent evolution can occur. All possibilities occur as a result of the wave function collapsing in all possible ways that the wave function can collapse up to the Heisenberg cut.

Must quantum immortality logically follow from the truth of MWI? Are we really each an immortal character in our own universe?

I don't understand quantum immortality enough to say anything. I suppose if immortality is consistent with a wave function collapse evolution.

What bizarre things on the macro level have been witnessed in this particular universe that we share (if we even do share the exact same universe) that may hint at the truth of MWI?

I think this comes close to a misinterpretation. There may be no macro level events that suggest the existence of alternate evolutions of the wave function aside from the quantum level laws themselves, but I don't really know.

What does this tell us about the possibility of Christianity or other religions (or gods) being true? If they are impossible here, would they still be considered impossible in all the other universes no matter how many parallel universes there may be?

I don't think the existence of a god in the traditional sense is compatible with ordinary quantum physics, so no, gods would not be a feature unless they are already a potential feature of this world line.

What does this tell us about the ability to predict anything in the future given that MWI is true?

I'm not sure I understand the question. From what I understand, MWI in some sense implies the B theory of time, that all possible evolutions of the wave function have already occurred. The most numerous world lines will be those that are most probable according to the laws of quatum mechanics, but if the B theory of time holds, all the possible world lines exist simultaneously (if that concept even has any meaning).

Finally, how do you feel about MWI being possibly true?

I'm a fan of MWI myself. But I really know too little about the physics to really have an opinion.

[Jackalope]

The Multi Universe was invented as another scheme to justify the belief that this place is not unique. Good luck on that one.

Have you ever considered sticking to things you actually have an understanding of?

Rhetorical question.

[Surgenator]

Alright, so I have some idea of how Many-Worlds interpretation works and why it's accepted by many top experts in the relevant fields as the most logical explanation (since it's seen as the most parsimonious and logical explanation for what goes on in the quantum world).

I, for one, do not accept this interpretation as true because I do not put such a high trust in our logic to explain bizarre things that go on in there, so I'm perfectly happy (for now) with the Copenhagen interpretation.

I don't know if you can test which interpretation is correct. All the interpretations produce the same results, so we can't differentiate them.

But what I'm interested here in this thread is what exactly does Many-Worlds interpretation imply if it is indeed true.

That you might have a T-rex walking through your living room in some other dimension. Other than that, nothing.

Must quantum immortality logically follow from the truth of MWI? Are we really each an immortal character in our own universe?

No. The laws in other universes don't change after a split.

What bizarre things on the macro level have been witnessed in this particular universe that we share (if we even do share the exact same universe) that may hint at the truth of MWI?

Currently nothing.

What does this tell us about the possibility of Christianity or other religions (or gods) being true? If they are impossible here, would they still be considered impossible in all the other universes no matter how many parallel universes there may be?

Laws of the universe still don't change. So any gods that arise will be limited by the universes laws. Still a no go for Xtians.

What does this tell us about the ability to predict anything in the future given that MWI is true?

Same it has been if Copenhagen interpretation is correct.

Finally, how do you feel about MWI being possibly true?

I feel very uneasy about it. I'm not very fond of idea of multipling the number of particles from each measurement. Also, I don't know why can't two or more universes can't interfere with each other.

[Alex K]

Surgenator,

It's not really an additional multiplying of particles. The MWI amounts to basically just taking what the Schrödinger equation gives you and running with it. The quantum superpositions of the observer which automatically occur when it is included in the qm state along with the measured system,already give you the many worlds from your perspective. Copenhagen tells you to artificially deviate from Schroedinger after a measurement and project this down to one of the observer states in the superposition. So in a sense its less parsimonious than MWI.

There a two issues with that, how to assign probabilities to the superpositions, and whether some states should be special, but those are technical details.

In this picture, the usual observed quantum interference, eg in the double slit, precisely *is* interference between universes. Interference between very dissimilar universes is ultra suppressed afaik because the wave functions have little overlap.

[Mudhammam]

The Multi Universe was invented as another scheme to justify the belief that this place is not unique. Good luck on that one.

Because if our Universe is "unique" then it requires... Godorsomethingofanother?... which requires nothing? That's what you consider a logical train of thought you say?