[TheOnlyMaster]

So lately I have been reading up on the Multiverse/Many worlds interpretation theory, I just wanted to know your opinions on the following:

I will try to keep this as least technical as possible.

As you know, the MWI consists of the idea that any decision you ever make will split the universe into as many possible outcomes of that decision as possible, so say for example, someone asks you if you want tea or coffee and you answer tea; at this point the universe will split and another "you" in another universe will have chosen coffee and yet another "you" will have said nothing and so on. If you consider this, you can safely say that anything that is a possible outcome in the world will have happened in another universe. With this in mind, if being able to somehow communicate with these other universes was at all possible then in one of the universes someone will have done it already.
Since we have not heard from any of the other universes, does this mean that communication between universes is not a possible outcome and therefore this theory will never be proven?

Would love to know your thoughts.

This post has been edited by TheOnlyMaster: 10 January 2012 - 03:12 PM

[jason.p]

I'm by no means up to speed with this theory but I would imagine that any divergence (if there were any) would be at quantum level and not at the point where you decide on a tea or coffee. Besides how could you be sure we're not flipping back and forwards between universes or dimensions all the time anyway

[TheOnlyMaster]

jason.p, on 10 January 2012 - 11:03 AM, said:

I'm by no means up to speed with this theory but I would imagine that any divergence (if there were any) would be at quantum level and not at the point where you decide on a tea or coffee. Besides how could you be sure we're not flipping back and forwards between universes or dimensions all the time anyway

I can tell you are most definitely not up to speed with the theory.


Yes, the theory does relate at quantum level but since we are made of atoms it relates to any decision you make also.
(The brain is made of atoms when you think it creates quantum movement, therefore if the world splits for each quantum movement possible it will create a universe for each decision possible)

Like I said I'm trying to keep it simple.

[timo]

I'm not sure if there is a "many worlds interpretation theory" at all. I think "interpretation" already is the classification of the "many worlds" idea, not part of the name. I have heard about the "many worlds interpretation", which I have understood to be an interpretation of quantum mechanics (an attempt to make QM intuitive), not a theory. I've not heard about a "many worlds theory". So to answer your question: I think that by default an interpretation cannot be proven, but only become mainstream or not (e.g. because of proving to be useful). The notion of a lot of parallel universes has not become the mainstream interpretation of probability theory. Even though one could expect more interactions between the parallel universes in QM, I still don't expect it to suddenly show much more useful, there.

Btw.: While some physicists may actually be thinking about the "many worlds interpretation", the only occasion I ever encountered it is presented by non-physicists on the Internet. That does not invalidate speaking about it, of course. But maybe take it as a warning sign that is may not be the hot topic in physics that some people seem to conceive it as. After all, "maybe when you make a decision the universe splits into two branches" alone is a thought on the intellectual level of a kid learning that actions have consequences (there may be more to the "many world" thing, though).

This post has been edited by timo: 10 January 2012 - 11:16 AM

[TheOnlyMaster]

timo, on 10 January 2012 - 11:15 AM, said:

I'm not sure if there is a "many worlds interpretation theory" at all. I think "interpretation" already is the classification of the "many worlds" idea, not part of the name. I have heard about the "many worlds interpretation", which I have understood to be an interpretation of quantum mechanics (an attempt to make QM intuitive), not a theory. I've not heard about a "many worlds theory". So to answer your question: I think that by default an interpretation cannot be proven, but only become mainstream or not (e.g. because of proving to be useful). The notion of a lot of parallel universes has not become the mainstream interpretation of probability theory. Even though one could expect more interactions between the parallel universes in QM, I still don't expect it to suddenly show much more useful, there.

Btw.: While some physicists may actually be thinking about the "many worlds interpretation", the only occasion I ever encountered it is presented by non-physicists on the Internet. That does not invalidate speaking about it, of course. But maybe take it as a warning sign that is may not be the hot topic in physics that some people seem to conceive it as. After all, "maybe when you make a decision the universe splits into two branches" alone is a thought on the intellectual level of a kid learning that actions have consequences (there may be more to the "many world" thing, though).

Whilst you are partly correct, this does not answer my question. Also, semantically speaking an interpretation is a theory.
As for it not being a hot topic, I would have to disagree with you because solving this is believed by many physicists to be key to unlocking the mysteries that still surround quantum physics. In fact, without this theory many other theories that have evolved for quantum physics would be completely wrong.

[calabi]

I dont believe a word of it.

So whom is the real you? Under Einstein theories isnt it said that all observation points are equal? You cant have one alternate you being the better you that makes the better choices, the universe would not work like that(I think)?

How can it be a choice if both choices are played out? Which one are you? How comes your existence appears to be contiguous? Is your perception and choices random? Just imagine the point at where the universes diverge where you make the decision between coffee or tea, and just really zoom into it, how comes theres no perception of it, its a pretty profound event? Or what if at that exact same time someone else makes a split decision event? Millions of people with millions of decisions all at the same time, you've got splits within splits all the way down massive amounts of energy and expansions.

Thats just a few questions I can think of right now, the whole thing gives me a headache. Maybe there is alternate universes for quantum events but not for us and our petty decisions.

[TheOnlyMaster]

calabi, on 10 January 2012 - 02:51 PM, said:

I dont believe a word of it.

So whom is the real you? Under Einstein theories isnt it said that all observation points are equal? You cant have one alternate you being the better you that makes the better choices, the universe would not work like that(I think)?

How can it be a choice if both choices are played out? Which one are you? How comes your existence appears to be contiguous? Is your perception and choices random? Just imagine the point at where the universes diverge where you make the decision between coffee or tea, and just really zoom into it, how comes theres no perception of it, its a pretty profound event? Or what if at that exact same time someone else makes a split decision event? Millions of people with millions of decisions all at the same time, you've got splits within splits all the way down massive amounts of energy and expansions.

Thats just a few questions I can think of right now, the whole thing gives me a headache. Maybe there is alternate universes for quantum events but not for us and our petty decisions.

Yes, it gives me headaches too
Yes, according to the theory, that is exactly what happens, there would be billions of alternate universes with billions of alternate "you" for every single decision you took in life. (I'm not saying I agree with it, in fact far from it. Just stating what the theory is about).

This theory was developed to explain particle movements at a quantum level but the reality is that we are all made from quantum particles (including our brains) and everything we do creates movement of these quantum particles and therefore splits the universe. Pretty crazy stuff.
I have read a new theory which I believe makes more sense, which states that multiple universes do exist but they are not created by "quantum splitting" instead they are created by black/white holes. Where a black hole will at the other end create a white hole where matter is poured into a new universe(creating a big bang). As far fetched as this seems, it would explain the problem of the quantum particles without the nonsense of splitting universes.

[swansont]

TheOnlyMaster, on 10 January 2012 - 11:22 AM, said:

Whilst you are partly correct, this does not answer my question. Also, semantically speaking an interpretation is a theory.

No, not really. Especially if there is no way to confirm it.

[Delta1212]

TheOnlyMaster, on 10 January 2012 - 10:49 AM, said:

So lately I have been reading up on the Multiverse/Many worlds interpretation theory, I just wanted to know your opinions on the following: I will try to keep this as least technical as possible. As you know, the MWI consists of the idea that any decision you ever make will split the universe into as many possible outcomes of that decision as possible, so say for example, someone asks you if you want tea or coffee and you answer tea; at this point the universe will split and another "you" in another universe will have chosen coffee and yet another "you" will have said nothing and so on. If you consider this, you can safely say that anything that is a possible outcome in the world will have happened in another universe. With this in mind, if being able to somehow communicate with these other universes was at all possible then in one of the universes someone will have done it already. Since we have not heard from any of the other universes, does this mean that communication between universes is not a possible outcome and therefore this theory will never be proven? Would love to know your thoughts.

How would you know if it had happened or not? Stuck as we are in this universe, for all we know, every other possible universe in existence is communicating with each other. If there are multiple universes, and it is possible to communicate between them, and this means that it will have happened in at least one universe, that doesn't necessarily mean that the universe they'd contact would be us. Or, if it was, another version of our universe that didn't receive the call could branch off each time. we could, in fact, be contacted by some alternate universe every minute of every day, we just happen to wind up in the version that keeps missing the call, that being a physically possible and therefore necessarily existent universe. So to sum up: It is possible for Many Worlds to be true, for contact between worlds to be possible and for us to never have been contacted all at the same time. Not, mind you, that I think those are all true statements, they just aren't mutually exclusive, which I believe was your question.

[questionposter]

Wouldn't having multiple universes mean that you'd need to create more matter and energy (or subtract it) to create another universe? Further more, wouldn't that mean a big bang had to be spontaneously created and have its time sped up? And if that happened, wouldn't that mean an outcome follows a deterministic path because another universe "HAS" to have a path that corresponds with something that wasn't picked and also you would need to speed time up for that universe detirministically so it created that path?

[Andeh]

From what I've gathered, the MUI states that the reality "splits" during wavefuntion collapse, where the wavefunction collapsed into each of it's possible states in each reality. It implies that everything began with a single reality, then divided like a branching tree as time went on.

But why not go the other direction?... Every possible reality already exists; that is the default state. In other words, reality isnt confined to any one universe until wavefunction collapse. There is no past or future...the movement of time as we see it arises (somehow) from the fact that every possible reality exists, including ones that we would view as being in the past or future.

p.s., I'm not nececerily educated enough to have an opinion, but I don't really like the MUI. It's too idealistic and has too many gaps that calabi and questionposer have already pointed out. But sometimes its fun to be idealistic.

[timo]

Andeh, on 15 January 2012 - 10:44 PM, said:

From what I've gathered, the MUI states that the reality "splits" during wavefuntion collapse, where the wavefunction collapsed into each of it's possible states in each reality. It implies that everything began with a single reality, then divided like a branching tree as time went on.

The former statement does actually not imply the latter - they are merely not mutually exclusive.

Quote

But why not go the other direction?... Every possible reality already exists; [...] reality isnt confined to any one universe until wavefunction collapse.

That's pretty much the mainstream view of quantum mechanics (note that I edited out part of what you said, which may have altered your original statement). EDIT: Oh, and of course one usually doesn't speak about "any one universe" but about "any one result of a measurement" (which is effectively my comment above: using the term "universe" sounds cool but adds nothing).

This post has been edited by timo: 15 January 2012 - 11:04 PM

[Andeh]

timo, on 15 January 2012 - 10:58 PM, said:

That's pretty much the mainstream view of quantum mechanics (note that I edited out part of what you said, which may have altered your original statement). EDIT: Oh, and of course one usually doesn't speak about "any one universe" but about "any one result of a measurement" (which is effectively my comment above: using the term "universe" sounds cool but adds nothing).

Yes, it does sound a lot like the copenhagan interpretation (I'm assuming that's what you mean by "the mainstream view")...
But does the copenhagen interpretation explain time in a similar way? It's been unclear to me what it's stance on time is, or if it even adresses the question of time at all.