Local QM? MWI, RQM, QFT, LQM, + ?

In summary: The superposition principle is acrazy postulate because it says that if you have a bunch of possible states of nature, all of which you could observe, then you can also observe any combination of those states. Crazy.
  • #36
setAI said:
no- because the MWI strictly speaking- is not an interpretation- but rather it accepts unitary QM as-it-is- which is the point- and the basis for much of it's appeal- there are no logical fallacies with the MWI- only aesthetic ones

There are if it's based on unitary QM alone, since their are problems here then it's equally riddled with the same intrinsic problems, to base a theory and an extrapolatory one at that on a theory that has flaws, mean that you are making at least two logical fallacies I can think of, did you read the links, they set it out quite neatly.

My colleague called Vanesches attempts, and please forgive me, his words not mine: arbitrary twaddle.:devil:

MWI to me is highlighting the problems with UQM and nothing else. This is good, but some people rightly take it with a pinch of salt for now.
 
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  • #37
Schrodinger's Dog said:
There are if it's based on unitary QM alone, since their are problems here then it's equally riddled with the same intrinsic problems, to base a theory and an extrapolatory one at that on a theory that has flaws

I fail to see any coherence in the argument you try to bring forward against what I'm saying. I never used any *examples* to generalise from.

I said the following:

MWI has the following advantages:
- it is in no known observational contradiction
- it is based upon the unitary axioms of quantum theory, and takes the claim seriously that what is called the quantum state, is a genuine physical state (all the time, and not only when this fits the arguments)
- it doesn't add a dichotomy by introducing two incompatible physical descriptions (classical and quantum) as CI does ; and it can explain the measurement process as just another physical process
- it can respect locality and Lorentz invariance in its ontology, and is (thanks to Bell's theorem) in that respect UNIQUE if it comes to being strictly equivalent to "standard" quantum mechanical statistical predictions (superdeterminism excluded)
- it doesn't add yet-to-be-specified-but-hypothetical-all-solving axioms

I have absolutely no idea how, to this list, your counter arguments apply, or logical fallacies, as you call them, are made.

, mean that you are making at least two logical fallacies I can think of, did you read the links, they set it out quite neatly.

The examples I took (the backside of Andromeda) were just to illustrate the *kind* of difficulty one runs into when *introducing* extra postulates which "cut away things which are not evidently observable and hence need to be cut away". It was just a way of showing you how ridiculous it can sometimes be to require explicit observability of a concept, which was an argument YOU used against MWI (the unobservability of the "other worlds").

If you think that "Bell's theorem" is just a small example, then I think you never deeply thought about its fundamental implications. Bell's theorem is ALL that sets apart quantum theory from yet another statistical model. It is the CORE difficulty of the measurement problem.

So, again, where in my argument did I use "proof by example" ?

My colleague called Vanesches attempts, and please forgive me, his words not mine: arbitrary twaddle.:devil:

This is somehow reassuring. I have never seen any SERIOUS argument against MWI. They are all of the derision kind, "too crazy", or "can't believe it" or "doesn't make any sense to me" or... but never a serious, well-build argument, like an inconsistency, or an observational difficulty. This appeal to emotional rejection without finding any rational argumentation is the main difficulty with MWI:

It is simply very weird (and hence intuitively hard to accept). It takes some sense of abstraction and philosphical "detachment" to even be able to contemplate what is being said.

MWI to me is highlighting the problems with UQM and nothing else. This is good, but some people rightly take it with a pinch of salt for now.

No, MWI illustrates the WEIRDNESS of the basic idea of quantum theory. An electron being at several places at once is JUST AS WEIRD as Bob having seen two results at once. Only, because we can tell ourselves that electrons can have it their weird way, this doesn't shock us ; but when it is good old Bob, we can't have it anymore. But that's our intuition which fails upon us.

I don't see *this* aspect as problematic per se. The serious problem facing UQM is rather gravity ; but we don't know yet whether or not there exists a unitary version of gravity. Maybe it does.
 
  • #38
vanesch said:
I fail to see any coherence in the argument you try to bring forward against what I'm saying. I never used any *examples* to generalise from.

I said the following:

MWI has the following advantages:
- it is in no known observational contradiction

The fairies at the bottom of the garden have no observational contradiction either.

- it is based upon the unitary axioms of quantum theory, and takes the claim seriously that what is called the quantum state, is a genuine physical state (all the time, and not only when this fits the arguments)

So is Schrodinger's World Interpritation. SWI or Single World Interpritation.

- it doesn't add a dichotomy by introducing two incompatible physical descriptions (classical and quantum) as CI does ; and it can explain the measurement process as just another physical process

ditto, and mines equally valid because of this. You can call it many worlds repackaged, I prefer to call it abritrary twaddle.

- it can respect locality and Lorentz invariance in its ontology, and is (thanks to Bell's theorem) in that respect UNIQUE if it comes to being strictly equivalent to "standard" quantum mechanical statistical predictions (superdeterminism excluded)

In philosophy you can show black is white.

- it doesn't add yet-to-be-specified-but-hypothetical-all-solving axioms

It doesn't add anything it just goes philosophy on our arses.

I have absolutely no idea how, to this list, your counter arguments apply, or logical fallacies, as you call them, are made.

Not surprised a logical fallacy is just that. If you can't counter it, maybe it's you who has the problem?

The examples I took (the backside of Andromeda) were just to illustrate the *kind* of difficulty one runs into when *introducing* extra postulates which "cut away things which are not evidently observable and hence need to be cut away". It was just a way of showing you how ridiculous it can sometimes be to require explicit observability of a concept, which was an argument YOU used against MWI (the unobservability of the "other worlds").

yes resort to the absurd. Another logical fallacy. Claim that without evidence and knowing that none will be forthcoming, their are infinite realities? Like string theory invent extra dimensions to solve the problem. But of course we may never detect them, o_O really *shrug*

If you think that "Bell's theorem" is just a small example, then I think you never deeply thought about its fundamental implications. Bell's theorem is ALL that sets apart quantum theory from yet another statistical model. It is the CORE difficulty of the measurement problem.

All this says to me is we don't know what is going on. A much healthier view.

So, again, where in my argument did I use "proof by example" ?

Since it's based on an already existent example, it's the same thing.

This is somehow reassuring. I have never seen any SERIOUS argument against MWI. They are all of the derision kind, "too crazy", or "can't believe it" or "doesn't make any sense to me" or... but never a serious, well-build argument, like an inconsistency, or an observational difficulty. This appeal to emotional rejection without finding any rational argumentation is the main difficulty with MWI:

How can someone argue against the Invisible Pink Unicorn? There's no evidence therefore there's no way you can form an argument, this isn't science though, it's like claiming the Unicorn is green.

It is simply very weird (and hence intuitively hard to accept). It takes some sense of abstraction and philosphical "detachment" to even be able to contemplate what is being said.

Oh no it doesn't, it takes some time to realize why you think it's arbitrary twaddle, that's it. It isn't a contraversial theory because of arbitrary reasons.
No, MWI illustrates the WEIRDNESS of the basic idea of quantum theory. An electron being at several places at once is JUST AS WEIRD as Bob having seen two results at once. Only, because we can tell ourselves that electrons can have it their weird way, this doesn't shock us ; but when it is good old Bob, we can't have it anymore. But that's our intuition which fails upon us.

I don't see *this* aspect as problematic per se. The serious problem facing UQM is rather gravity ; but we don't know yet whether or not there exists a unitary version of gravity. Maybe it does.

It demonstrates perfectly how little we know, and just how far we're willing to take an argument based on nothing evidential but a theory that has flaws. The serious problem facing science is that we cannot measure what we're porporting to see directly, so anything we come up with now is prone to interpritational errors. Basing new theories on a suspect old one is fine and speculatory, but it is not science. I have a beef with Stephen Hawking saying radiation leaks from a black hole for this very reason? Ie what black hole :biggrin: Light travels faster than light in a black hole? yes I'm sure it does in maths world.

At the end of the day QM was founded on inference, if those inferences are wrong then we have more work to do, speculation is of course robust and worthy, but I'd hate to see mathemeticians trying to come up with anything here. It would be like string theory an excercise in sophistry.
 
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  • #39
Schrodinger's Dog said:
The fairies at the bottom of the garden don't either.

Yes, but can you show me where the introduction of fairies at the bottom of the garden DID provide any explanation for observation ? Because this is the point. You equate the superposition principle (that is, the physical state containing at the same time several observational variants - of which of course only one is actually observed by an observer, by definition) with "fairies at the bottom of the garden". However, the superposition principle was the principal motivation to introduce the Hilbert space formalism, out of which came lots of verified experimental predictions, going from the spectrum of Helium to all other kinds of experimental successes of quantum theory.

So I don't see how you can equate a WORKING PRINCIPLE with "fairies at the bottom of the garden". The last ones never had, in no circumstance, any verifiable observational consequences, while the former did.

So is Schrodinger's world interpritation.

What is Schroedinger's world interpretation ? What exactly is a physical state, and what exactly is a measurement ? Exactly how does this work ? I'm curious...

In philosophy you can show black is white.

This is a ridiculous statement, only meant to get some "general opinion of the ignorant public on your hand", in other words, cheap rethoric. It doesn't contain any argument.

Not surprised a logical fallacy is just that.

It is not an argument to shout "logical fallacy, logical fallacy" in order for an argument to be a logical fallacy. Again, cheap rethoric.

yes resort to the absurd. Another logical fallacy.

First of all, resorting to the absurd is not a logical fallacy, but a well-recognized method of argumentation: trying to reduce the other person's counter argument to be equivalent to an absurd situation results in showing that there is a logical fallacy in the COUNTER argument (yours!), and is by itself an entirely valid way of reasoning (reductio ad absurdum).

All this says to me is we don't know what is going on. A much healthier view.

Why is the argument (which is always correct) that "we might not know what is going on" an argument against a coherent construction which *can explain* what is going on ? I will again use a "reductio ad absurdum" to show you that this kind of reasoning is fallacious.
Remember, there was an ancient Greek who found that the day that the sun shone right into a water pit in Syene, it made an angle of about 7 degrees in Alexandria. From this he concluded that the Earth was round and calculated its circumference, which came out to about 99% of the actual value. Now, for a proponent of intuitively appealing "flat earth" views, he can always claim that the mathematical model of a spherical Earth gives correct predictions, but that the evident conclusion that follows from this mathematics, namely that the Earth is spherical, is just like fairies at the bottom of the garden, because this cannot be directly observed. He insists upon the "flat earth" interpretation, and concludes from the admittedly strange mathematical predictions of the "spherical Earth model" that all this simply says that we don't know what is going on, but refuses obstinately to consider that the Earth might effectively be a sphere. In a philosophical sense, he's right of course: we cannot really know whether the Earth is really spherical. But in what way does this argument invalidate the entirely coherent EXPLANATION of several observations, including the observation that locally, the Earth LOOKS flat all right to beings of our size, and the light in the pit at Seyene ?
Is stating that the Earth is really round (against our daily intuition, which confirms us that it is flat), simply based upon the formalism which helps us explain several observations, including "puzzling ones", invoking "fairies at the bottom of the garden" ?

Since it's based on an already existent example, it's the same thing.

What example ?

How can someone argue against the Invisible Pink Unicorn? There's no evidence therefore there's no way you can form an argument, this isn't science though, it's like claiming the Unicorn is green.

No, you could come up with a coherent explanation, without the unicorn. I've never seen any coherent explanation, apart from MWI, which
1) respects lorentz invariance
2) respects all the observable predictions of unitary quantum theory
3) presents us with an actual ontology of what is going on.

The day that you find one, let me know. But, don't talk to me about a *hypothetical one* that should have such and such properties, without telling me exactly how it works. It is in the details that those things go wrong.

It demonstrates perfectly how little we know, and just how far we're willing to take an argument based on nothing. The serious problem facing science is that we cannot measure what we're porporting to see directly, so anything we come up with now is prone to interpritational errors. Basing new theories on a suspect old one is fine and speculatory, but it is not science. I have a beef with Stephen Hawking saying radiation leaks from a black hole for this very reason? Ie what black hole :D Light travels faster than light in a black hole? yes I'm sure it does in maths world.

Andromeda sends out light to the back of the heavenly sphere on which it is painted ? Yes, I'm sure it does in maths world.
 
  • #40
vanesch said:
Yes, but can you show me where the introduction of fairies at the bottom of the garden DID provide any explanation for observation ? Because this is the point. You equate the superposition principle (that is, the physical state containing at the same time several observational variants - of which of course only one is actually observed by an observer, by definition) with "fairies at the bottom of the garden". However, the superposition principle was the principal motivation to introduce the Hilbert space formalism, out of which came lots of verified experimental predictions, going from the spectrum of Helium to all other kinds of experimental successes of quantum theory.

So I don't see how you can equate a WORKING PRINCIPLE with "fairies at the bottom of the garden". The last ones never had, in no circumstance, any verifiable observational consequences, while the former did.
What is Schroedinger's world interpretation ? What exactly is a physical state, and what exactly is a measurement ? Exactly how does this work ? I'm curious...
This is a ridiculous statement, only meant to get some "general opinion of the ignorant public on your hand", in other words, cheap rethoric. It doesn't contain any argument.
It is not an argument to shout "logical fallacy, logical fallacy" in order for an argument to be a logical fallacy. Again, cheap rethoric.
First of all, resorting to the absurd is not a logical fallacy, but a well-recognized method of argumentation: trying to reduce the other person's counter argument to be equivalent to an absurd situation results in showing that there is a logical fallacy in the COUNTER argument (yours!), and is by itself an entirely valid way of reasoning (reductio ad absurdum).
Why is the argument (which is always correct) that "we might not know what is going on" an argument against a coherent construction which *can explain* what is going on ? I will again use a "reductio ad absurdum" to show you that this kind of reasoning is fallacious.
Remember, there was an ancient Greek who found that the day that the sun shone right into a water pit in Syene, it made an angle of about 7 degrees in Alexandria. From this he concluded that the Earth was round and calculated its circumference, which came out to about 99% of the actual value. Now, for a proponent of intuitively appealing "flat earth" views, he can always claim that the mathematical model of a spherical Earth gives correct predictions, but that the evident conclusion that follows from this mathematics, namely that the Earth is spherical, is just like fairies at the bottom of the garden, because this cannot be directly observed. He insists upon the "flat earth" interpretation, and concludes from the admittedly strange mathematical predictions of the "spherical Earth model" that all this simply says that we don't know what is going on, but refuses obstinately to consider that the Earth might effectively be a sphere. In a philosophical sense, he's right of course: we cannot really know whether the Earth is really spherical. But in what way does this argument invalidate the entirely coherent EXPLANATION of several observations, including the observation that locally, the Earth LOOKS flat all right to beings of our size, and the light in the pit at Seyene ?
Is stating that the Earth is really round (against our daily intuition, which confirms us that it is flat), simply based upon the formalism which helps us explain several observations, including "puzzling ones", invoking "fairies at the bottom of the garden" ?
What example ?
No, you could come up with a coherent explanation, without the unicorn. I've never seen any coherent explanation, apart from MWI, which
1) respects lorentz invariance
2) respects all the observable predictions of unitary quantum theory
3) presents us with an actual ontology of what is going on.

The day that you find one, let me know. But, don't talk to me about a *hypothetical one* that should have such and such properties, without telling me exactly how it works. It is in the details that those things go wrong.
Andromeda sends out light to the back of the heavenly sphere on which it is painted ? Yes, I'm sure it does in maths world.

The only difference between SWI and MWI is I'm not claiming it's true, I just thought it up in five seconds, it is your theory in a single world, is it more or less valid? Answer this and I'll come up with another one, answer this and tomorrow I'll come up with another one. Just because it respects all the known implications, doesn't make it true by default, string theory does? Is it more valid or less valid than MWI? This is what we mean by arbitrary twaddle, the idea that having no substance has more substance than another theory that actually has substance is an excercise in semantics, as simple as that.

I know how much you value MWI? But I think you're in for some serious dissapointment.

I'm sorry if this bothers you, but I'm simply asking you to do one thing, prove it and not by example or a thought experiment which indicates we're still in the dark.
 
  • #41
A question for vanesch:
Would MWI be viable if \psi satisfied a NON-linear equation?
 
  • #42
Schrodinger's Dog said:
The only difference between SWI and MWI is I'm not claiming it's true

Yes, that has about the same value as claiming that the Earth is flat, nevertheless. To the guy who tells you that the "best and most coherent view, based upon what we know today, and of course open to any modification in the future if observation requires it, is that the Earth is spherical" you answer, that you think that the Earth is flat, that you actually don't claim that is true, and this is supposed to invalidate the guy's argument ??

In order to come up with an idea, it has to have some consistence to it. Of course, to ANY coherent set of explanations, you can come up with a quickly thought up set of different statements, of which you don't bother that they give rise to inconsistencies, of which you're not claiming it is true ; but is that an argument against the original coherent set of explanations ?

I just thought it up in five seconds, it is your theory in a single world, is it more or less valid? Answer this and I'll come up with another one, answer this and tomorrow I'll come up with another one. Just because it respects all the known implications, doesn't make it true by default, string theory does? Is it more valid or less valid than MWI?

But do you actually know what you are talking about ? What has string theory to do with this ? There isn't even a clear set of postulates for string theory, and moreover, string theory is STILL another model within unitary quantum theory.

This is what we mean by arbitrary twaddle, the idea that having no substance has more substance than another theory that actually has substance is an excercise in semantics, as simple as that.

You never answered my question: do you think that there is light emitted to the backside of Andromeda, or not, or do you remain entirely agnostic about it ? And what is your argumentation for your position ?

I know how much you value MWI? But I think you're in for some serious dissapointment.

I don't value MWI in any specific way beyond quantum theory in its current, unitary formulation. I claim that if all we know, is current quantum theory, then a lot of "paradoxes" disappear when you look upon it from an MWI viewpoint, and that's kind of evident, given that MWI is simply taking the postulates of that very same unitary quantum theory seriously.

I'm sorry if this bothers you, but I'm simply asking you to do one thing, prove it and not by example or a thought experiment which indicates we're still in the dark.

You cannot *prove* a scientific theory. You can at best falsify it, and that's always done in a specific setting, with specific examples.

You would even have difficulties proving that the Earth is genuinely spherical: one can build an entirely consistent view of space in which Earth is actually space-filling, except for a hole in the middle, and we are living on the *inside* of that surface. The only thing you have to do for that is to assume that the metric of space is not Euclidean, but underwent a conformal transformation r -> 1/r.

Prove me that there is, or that there isn't, any light emitted from the back of andromeda.
 
  • #43
Demystifier said:
A question for vanesch:
Would MWI be viable if \psi satisfied a NON-linear equation?

No.

It is absolutely essential for the evolution equation to be strictly linear, because it is the only way to "keep the other worlds from being observable". In fact, I like somehow Penrose's idea that gravity might kill off unitarity - which would then finally allow for a genuine collapse. That would then be the end of unitary quantum theory, and would restrict MWI as an approximation which is only valid for as long as the non-linearities don't come into play (say, during a few microseconds or so). Only, I don't think that anybody ever managed to work out such a thing, so this is again part of the hypothetical-unspecified-postulate-that-would-solve-it-all.
And in any case, such a non-linearity would imply a form of non-locality.
 
  • #45
Demystifier said:
I agree.
But then I wonder how would you interpret the fact that classical mechanics can be viewed as a non-linear quantum mechanics?
http://arxiv.org/abs/quant-ph/0505143

I just skimmed through the paper, without reading it in detail. The thing that hit me was the following:
With such a
positivistic scientific reasoning, if a determininistic theory (such as the Bohmian interpretation
of QM) can be replaced with a simpler indeterministic theory (such as QM with the usual interpretation)
that leads to the same measurable predictions, then it is the latter indeterministic
theory that should be adopted as a more fundamental theory.

I find this the "inverse view". The problem is not to find a "simpler indeterministic theory", but rather the opposite: to try to find an ontological view for a positivist formalism!

The author seems to argue that this is the main objection to Bohmian mechanics: namely that it "is not positivist" but tries to give an ontology.

I'd rather say, the opposite! If it was not for relativity, in my eyes *it would be obvious* that Bohmian mechanics is the most natural way to see quantum theory. The problem with Bohmian mechanics is essentially its non-lorentz invariant character (from which also results the difficulty of having a Bohmian version of QFT).

I only skimmed through the rest ; apparently the idea is to construct a wave mechanics which is equivalent to the Liouvillian flow of the probability density in phase space.
However, I think that the essential point is: the "state" as such defined satisfies the axioms of a Kolmogorov probability distribution. As such, it is almost evident that the "natural view" is the underlying deterministic model.
But the quantum-mechanical wavefunction does NOT give rise to a Kolmogorov probability distribution over a state space with a local dynamics. THIS is the essential difficulty.

Otherwise, the famous "superposition principle" would indeed just be reduced to a probability distribution. But it can't, if we insist upon local dynamics.
 
  • #46
vanesch said:
Yes, that has about the same value as claiming that the Earth is flat, nevertheless. To the guy who tells you that the "best and most coherent view, based upon what we know today, and of course open to any modification in the future if observation requires it, is that the Earth is spherical" you answer, that you think that the Earth is flat, that you actually don't claim that is true, and this is supposed to invalidate the guy's argument ??

In order to come up with an idea, it has to have some consistence to it. Of course, to ANY coherent set of explanations, you can come up with a quickly thought up set of different statements, of which you don't bother that they give rise to inconsistencies, of which you're not claiming it is true ; but is that an argument against the original coherent set of explanations ?
But do you actually know what you are talking about ? What has string theory to do with this ? There isn't even a clear set of postulates for string theory, and moreover, string theory is STILL another model within unitary quantum theory.
You never answered my question: do you think that there is light emitted to the backside of Andromeda, or not, or do you remain entirely agnostic about it ? And what is your argumentation for your position ?
I don't value MWI in any specific way beyond quantum theory in its current, unitary formulation. I claim that if all we know, is current quantum theory, then a lot of "paradoxes" disappear when you look upon it from an MWI viewpoint, and that's kind of evident, given that MWI is simply taking the postulates of that very same unitary quantum theory seriously.
You cannot *prove* a scientific theory. You can at best falsify it, and that's always done in a specific setting, with specific examples.

You would even have difficulties proving that the Earth is genuinely spherical: one can build an entirely consistent view of space in which Earth is actually space-filling, except for a hole in the middle, and we are living on the *inside* of that surface. The only thing you have to do for that is to assume that the metric of space is not Euclidean, but underwent a conformal transformation r -> 1/r.

Prove me that there is, or that there isn't, any light emitted from the back of andromeda.
Since yours is non falsifiable, it is like string theory not even wrong.

And since we're never going to get any proof of it, it's what I tend to think of as a cop out, everything's weird and will only get wierder there are no answers let's all sing kumbuya and lament the death of science.

Now that's a resort to the absurd.:)

Essentially no one can argue with you? Theirs nothing to argue against accept the current theory. And you'll find plenty of people doing that, problem is it's an effort in semantics to talk about MWI, as it is to comprehend it.

Is it worth the effort? I haven't seen much sign yet? Is it a dead end, yes a philosophical one? So what's best to do? Find something better and leave this theory in the happy box.

:biggrin:

I understand it well enough to know why my colleague calls it arbitrary twaddle.

Maybe I should ask him if he thinks he has a point?
 
  • #47
Schrodinger's Dog said:
Since yours is non falsifiable, it is like string theory not even wrong.

The superposition principle is not falsifiable ?

And since we're never going to get any proof of it, it's what I tend to think of as a cop out, everything's weird and will only get wierder there are no answers let's all sing kumbuya and lament the death of science.

So to you, science is restricted to the immediately observable and intuitively obvious ?

Essentially no one can argue with you? Theirs nothing to argue against accept the current theory. And you'll find plenty of people doing that, problem is it's an effort in semantics to talk about MWI, as it is to comprehend it.

Many people think that there is something *fundamentally wrong* with quantum theory, because they build themselves a picture which is partly based upon the theory, and partly upon their intuitive desires. When they do that, they run into contradictions, "impossibilities" and so on, and from that they conclude that QM "must be wrong", or "must be incomplete". CI is a typical example of such a garbled mixture of concepts, with contradictions abound. For those people, it is I think very helpful to consider MWI as a picture - since apparently they need a picture, and they base their judgment of the validity of quantum theory entirely upon that picture. I know of some people who totally ruined their careers simply based upon such a kind of argument, and that's a pity.
So my claim is that the argument that quantum theory must be fundamentally wrong, simply based upon the inconsistencies of a *picture* (to which was added some extra input based upon intuitive desires), is a flawed argument.

However, it is not because an argument is wrong, that its conclusion is wrong! So it is very well conceivable that quantum theory IS indeed wrong, incomplete, whatever. However, the argument about the picture is not its proof. The only argument can be empirical, in the end: showing a falsification of quantum theory.

Is it worth the effort? I haven't seen much sign yet? Is it a dead end, yes a philosophical one? So what's best to do? Find something better and leave this theory in the happy box.

Maybe there IS nothing "better". (then, maybe there is, but not for *this* reason) So you should be prepared to live with it. Now, if you can live with quantum theory without any problem, then that's fine. But when you see how many people have difficulties accepting quantum theory, purely based upon the picture they have of it, then it is certainly worth the effort. When you see that some people ruined their careers looking for an agreement between their intuitive desires, and quantum theory, I'm pretty convinced that giving a coherent picture, no matter how weird, but coherent, of the theory can free yourself of having to tell yourself that deep down, nature doesn't really make sense if it is described by quantum theory (from which follow two (bad) reactions: or you're convinced that nature ought to make sense, and hence refute quantum theory, or you're convinced that, given that nature doesn't make sense, anything goes). Just look simply here at PF, how many difficulties people have with a picture of quantum theory. Almost one thread out of two has to do with interpretation issues.

It is funny to read how much trouble Newton had accepting his concept of "force at a distance". I don't have the book handy, but he writes himself somehow that even contemplating the idea that something could have an influence on something else, far separated from it by nothing else but vacuum, was to him a crazy and even inconceivable idea.

New paradigms are always difficult to swallow, and we often end up making a mockup of the new paradigm with elements of the old one - which usually leads to an inconsistency.

I understand it well enough to know why my colleague calls it arbitrary twaddle.

Maybe I should ask him if he thinks he has a point?

I think that if he had one, he would have given it... but try along !
I'm pretty sure it will come down to just a statement of "nah, that's simply too crazy an idea" or a similar derogatory expression of emotion. I know of no *rational* argumentation against MWI (which is also not an argument against quantum theory in general). In fact, MWI *saves* quantum theory from two deadly arguments against it, which is 1) non-locality and 2) inconsistency concerning the "measurement apparatus considered as a system".
 
  • #48
vanesch said:
The superposition principle is not falsifiable ?
So to you, science is restricted to the immediately observable and intuitively obvious ?
Many people think that there is something *fundamentally wrong* with quantum theory, because they build themselves a picture which is partly based upon the theory, and partly upon their intuitive desires. When they do that, they run into contradictions, "impossibilities" and so on, and from that they conclude that QM "must be wrong", or "must be incomplete". CI is a typical example of such a garbled mixture of concepts, with contradictions abound. For those people, it is I think very helpful to consider MWI as a picture - since apparently they need a picture, and they base their judgment of the validity of quantum theory entirely upon that picture. I know of some people who totally ruined their careers simply based upon such a kind of argument, and that's a pity.
So my claim is that the argument that quantum theory must be fundamentally wrong, simply based upon the inconsistencies of a *picture* (to which was added some extra input based upon intuitive desires), is a flawed argument.

However, it is not because an argument is wrong, that its conclusion is wrong! So it is very well conceivable that quantum theory IS indeed wrong, incomplete, whatever. However, the argument about the picture is not its proof. The only argument can be empirical, in the end: showing a falsification of quantum theory.
Maybe there IS nothing "better". (then, maybe there is, but not for *this* reason) So you should be prepared to live with it. Now, if you can live with quantum theory without any problem, then that's fine. But when you see how many people have difficulties accepting quantum theory, purely based upon the picture they have of it, then it is certainly worth the effort. When you see that some people ruined their careers looking for an agreement between their intuitive desires, and quantum theory, I'm pretty convinced that giving a coherent picture, no matter how weird, but coherent, of the theory can free yourself of having to tell yourself that deep down, nature doesn't really make sense if it is described by quantum theory (from which follow two (bad) reactions: or you're convinced that nature ought to make sense, and hence refute quantum theory, or you're convinced that, given that nature doesn't make sense, anything goes). Just look simply here at PF, how many difficulties people have with a picture of quantum theory. Almost one thread out of two has to do with interpretation issues.

It is funny to read how much trouble Newton had accepting his concept of "force at a distance". I don't have the book handy, but he writes himself somehow that even contemplating the idea that something could have an influence on something else, far separated from it by nothing else but vacuum, was to him a crazy and even inconceivable idea.

New paradigms are always difficult to swallow, and we often end up making a mockup of the new paradigm with elements of the old one - which usually leads to an inconsistency.
I think that if he had one, he would have given it... but try along !
I'm pretty sure it will come down to just a statement of "nah, that's simply too crazy an idea" or a similar derogatory expression of emotion. I know of no *rational* argumentation against MWI (which is also not an argument against quantum theory in general). In fact, MWI *saves* quantum theory from two deadly arguments against it, which is 1) non-locality and 2) inconsistency concerning the "measurement apparatus considered as a system".
Is it a Paradigm or a fallacious argument though, premise based on a false premise? I have problems with quantum theory like everyone does.

Feynman died still having problems with it.

Bohr said that anyone who is shocked by quantum mechanics hasn't understood it and at the time he was right.

However there's a difference between being mystified by the apparent chaos at the heart of QM, and inventing new realities to account for them, this is my only beef with MWI, but it's a pretty big one. I understand that it's your view, but frankly I| sincerely hope science does not get swayed by it.

That is my personal opinion, and my colleague thinks your just talking twaddle: still? Who's right, time will tell :smile:

He's betting his Doctorate on you being wrong though:wink: :tongue::smile: :devil:
 
  • #49
Schrodinger's Dog said:
Bohr said that anyone who is shocked by quantum mechanics hasn't understood it and at the time he was right.

One can be shocked by its weirdness. In fact, if one isn't, then one hasn't understood it.

However there's a difference between being mystified by the apparent chaos at the heart of QM, and inventing new realities to account for them, this is my only beef with MWI, but it's a pretty big one.

How to make you see that there are no new realities *invented*, but that they FOLLOW if you strictly apply the axioms of quantum theory to everything, the observer included ?

THIS is why I'm referring to "the light emitted to the back of Andromeda". To someone who intuitively thinks that the heavenly bodies are just holes in a kind of big celestial sphere, the concept of "light emitted to the back of Andromeda" doesn't make any sense. When you explain to him some stellar models, and electromagnetism and wave propagation in space, he might object that all this theorizing just helps you calculate some things about the light coming from Andromeda (which, in his mind's eye, is STILL just a hole in the celestial sphere). And he might object that you *invent* some light emitted to the "back of Andromeda" just to fit your picture.
The argument about *inventing* new realities sounds exactly similar. When you consider that the "observer" is describable by quantum theory, together with his system, and you apply the axioms of quantum theory to the overall system, then you have to assign a hilbert space of states to the "observer+system" system, and a hamiltonian.
When you do that, you find out that your observer+system ends up in a kind of quantum state which looks like:
|observer_saw_A> |system_in_state_A> + |observer_saw_B> |system_in_state_B>

I'm not inventing this, everyone recognizes this, it is even written down in von Neuman's book "mathematical foundations of quantum theory". He calls it "the pre-measurement interaction".

von Neumann (very well aware of the difficulty), then goes on saying that "nature now switches from one kind of process to another at some level" (from "process 2" to "process 1"), and the observer, which was in two states, suddenly finds himself into one state (collapse).
von Neuman even almost hints at MWI, when he says that he cannot place this switching of process 2 to process 1 anywhere, strictly speaking, but that it must happen in between the system level, and the observer's conscious experience.

So the very fact that strictly applying standard quantum theory to the "observer+system" system, leads to an observer in a superposition of two "states of observation", should indicate that one doesn't INVENT any "new realities". One has to EXPLICITLY CUT AWAY part of the answer quantum theory gives us. We have to CUT AWAY the different superposed "states of observation" by hand if we want to end up with a quantum state of the observer in which he has one unique observation. It is this cutting away which gives rise to all the problems.

That is my personal opinion, and my colleague thinks your just talking twaddle: still? Who's right, time will tell :smile:

He's betting his Doctorate on you being wrong though:wink: :tongue::smile: :devil:

I would like to know exactly what he understands by "me being wrong" in this context, and how he is going to show this. Because, again, I'm not claiming that MWI is ultimately true. I'm saying that MWI is the natural view which goes with unitary quantum theory, and that this view can save you a lot of trouble, avoiding paradoxes which didn't have to be.
So he bets his doctorate upon that he's going to show me that MWI is NOT the natural view on unitary quantum theory ? I really wonder how he's going to handle that. Tell me when he's given up, I'll mail him my postal address (for his doctorate) :biggrin:
 
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  • #50
vanesch said:
But the quantum-mechanical wavefunction does NOT give rise to a Kolmogorov probability distribution over a state space with a local dynamics. THIS is the essential difficulty.
Although I agree with you, most practical users of QM who do not take seriously the Bohmian interpretation are not even fully aware of the problem of quantum nonlocalities. These practical users represent the majority of physicists and their arguments against Bohm are based on positivism, rather than locality. The paper mentioned above was written with the intention to provoke thinking of this majority.

However, the reason I mentioned the paper above to you was quite different. Linear equations in physics are usually regarded as approximations of nonlinear ones. From this point of view, it seems rather unreasonable to adopt an interpretation that makes sense only in the linear case.
 
  • #51
vanesch said:
One can be shocked by its weirdness. In fact, if one isn't, then one hasn't understood it.



How to make you see that there are no new realities *invented*, but that they FOLLOW if you strictly apply the axioms of quantum theory to everything, the observer included ?

THIS is why I'm referring to "the light emitted to the back of Andromeda". To someone who intuitively thinks that the heavenly bodies are just holes in a kind of big celestial sphere, the concept of "light emitted to the back of Andromeda" doesn't make any sense. When you explain to him some stellar models, and electromagnetism and wave propagation in space, he might object that all this theorizing just helps you calculate some things about the light coming from Andromeda (which, in his mind's eye, is STILL just a hole in the celestial sphere). And he might object that you *invent* some light emitted to the "back of Andromeda" just to fit your picture.
The argument about *inventing* new realities sounds exactly similar. When you consider that the "observer" is describable by quantum theory, together with his system, and you apply the axioms of quantum theory to the overall system, then you have to assign a hilbert space of states to the "observer+system" system, and a hamiltonian.
When you do that, you find out that your observer+system ends up in a kind of quantum state which looks like:
|observer_saw_A> |system_in_state_A> + |observer_saw_B> |system_in_state_B>

I'm not inventing this, everyone recognizes this, it is even written down in von Neuman's book "mathematical foundations of quantum theory". He calls it "the pre-measurement interaction".

von Neumann (very well aware of the difficulty), then goes on saying that "nature now switches from one kind of process to another at some level" (from "process 2" to "process 1"), and the observer, which was in two states, suddenly finds himself into one state (collapse).
von Neuman even almost hints at MWI, when he says that he cannot place this switching of process 2 to process 1 anywhere, strictly speaking, but that it must happen in between the system level, and the observer's conscious experience.

So the very fact that strictly applying standard quantum theory to the "observer+system" system, leads to an observer in a superposition of two "states of observation", should indicate that one doesn't INVENT any "new realities". One has to EXPLICITLY CUT AWAY part of the answer quantum theory gives us. We have to CUT AWAY the different superposed "states of observation" by hand if we want to end up with a quantum state of the observer in which he has one unique observation. It is this cutting away which gives rise to all the problems.



I would like to know exactly what he understands by "me being wrong" in this context, and how he is going to show this. Because, again, I'm not claiming that MWI is ultimately true. I'm saying that MWI is the natural view which goes with unitary quantum theory, and that this view can save you a lot of trouble, avoiding paradoxes which didn't have to be.
So he bets his doctorate upon that he's going to show me that MWI is NOT the natural view on unitary quantum theory ? I really wonder how he's going to handle that. Tell me when he's given up, I'll mail him my postal address (for his doctorate) :biggrin:


considering he feels the current theory is wrong then yes, pretty much I'm sure he would, he's got issues with most accepted facts though, that's his opinion. He's currently at odds with using imaginary numbers and is trying to find a 3d-spin solution without resorting to imaginary numbers, but he's almost given up in spherical polar co-ordinates even with i.

He's the sort of person who's vigorously looking into the cracks to see if he can find anything. OK maybe not his PhD but he still thinks you are making airy fairy philosophical hand wavey gestures.

Again his words not mine :biggrin:

I know what your saying, and I'm not majorly in disagreement, but I think he's probably right, the assumption is based on flaws. Anyway, I think we've extended everyones knowledge of MWI, and maybe had a little fun while we're at it: I guess we'll just have to agree to disagree, although to be frank I now don't dismiss it as sci fi, and have learned a great deal about what lies beneath. So thanks a bundle for that Vanesch and I hope this has been educational to more people than just me

:biggrin:
 
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  • #52
Demystifier said:
However, the reason I mentioned the paper above to you was quite different. Linear equations in physics are usually regarded as approximations of nonlinear ones. From this point of view, it seems rather unreasonable to adopt an interpretation that makes sense only in the linear case.

I agree. However, the funny thing with QM is that the slightest non-linearity destroys the strict locality of it in an EPR setting. It is only when strict unitarity is respected that one can avoid signaling FTL with entangled systems. As I said, Penrose thinks somehow that gravity might be responsible for this breaking of unitarity (but it would then as well give problems with GR on a small scale), the reason for this being that the "time" used in the Schroedinger equation will depend upon the "gravitational quantum state" or something of the kind. However, this is thinking out loud, and I don't think he got this really up and running.

So it is not that easy to modify quantum theory into a "slightly nonlinear version" without running into a lot of troubles that are absent in the strictly linear version ; and even in that case, the MWI interpretation will then still be a good approximation for the "linear part" (even if it is only limited to a few milliseconds, and a few thousand kilometer, say, a domain over which GR shouldn't be fully valid in that case, given the non-local character of the non-linearity it introduces). But such deviations from strict linearity should, sooner or later, be empirically observable and contradict interference predictions by unitary quantum theory. The EPR-Bell situation will then probably not arise outside of this "domain of validity of the unitary approximation", and its very resolution will tell us then what exactly happens.

Remember that I'm only a proponent of MWI in as far as unitary quantum theory is valid, because I think that, *within this domain of validity*, it gives one the most natural description as derived from the formalism, and explains quite in a straightforward way, things which seem almost incomprehensible in a "projection-based" view, mainly EPR situations and quantum erasure experiments. As of now, we haven't any idea of whether this strict unitarity is universally valid or only restricted to a certain domain. We only know that there are difficulties including gravity - but we don't know how serious these difficulties are. So in absence of any empirical indication, nor good formal reason, to give up unitarity, and knowing that it will introduce more problems than it solves, for the moment I keep it.
 
  • #54
vanesch said:
I don't know if you noticed it, but we have, as of today, only an incomplete description of physics. So we don't HAVE the postulates of all of physics.

Vanesch, come on! I don't know if you noticed it, but the formulation of the complete set of the principal postulates of Geometry was achieved about 3000 years ago. I don't know if you noticed it, but it did not stop the development of the Geometry which is continued successfully also today. They are the Rules of the Game and not the Game itself. Indeed, you may define them according to any of your interpretations. I have nothing against that.
 
  • #55
Anonym said:
Vanesch, come on! I don't know if you noticed it, but the formulation of the complete set of the principal postulates of Geometry was achieved about 3000 years ago. I don't know if you noticed it, but it did not stop the development of the Geometry which is continued successfully also today. They are the Rules of the Game and not the Game itself. Indeed, you may define them according to any of your interpretations. I have nothing against that.
Not even close. Euclid's postulates are for one specific entity (a Euclidean plane), and they were far from complete.
 
  • #56
vanesch said:
The superposition principle is not falsifiable ?
/snip

I think that if he had one, he would have given it... but try along !
I'm pretty sure it will come down to just a statement of "nah, that's simply too crazy an idea" or a similar derogatory expression of emotion. I know of no *rational* argumentation against MWI (which is also not an argument against quantum theory in general). In fact, MWI *saves* quantum theory from two deadly arguments against it, which is 1) non-locality and 2) inconsistency concerning the "measurement apparatus considered as a system".
Can I just say I'm being a devils advocate here now, after listening to your ideas, I think it has merit, and that this is valid criticism if you see what I mean. And I hope I haven't offended anyone by being forthright, if I have give me a few days off and I'll happily agree I deserve it, I really do think Vanesch that amongst the mentors you and ZZ,Berkman,Evo, etc(in no order of prefference, and don't forget if I forgot your name I'm picking favourites, I just am crap with names, Space Tiger :smile:) et al and many of the others are quite excellent in conveying your ideas, and that's why I have such a respect for this forum. And your cohorts of supporters are supporters because of that, and I respect them also.

I will uphold one caveat though, my colleague thinks you're wrong, he knows an infinite amount more than me(ok not infinite) But you see what I mean.

Now that said, I think their are flaws, and I think my colleague has a point, but I also after listening to your very clear ideas, and OK throwing in a few spanners think you have a very good case for a theory, if only that it's a hypothesis atm. OK I don't think it's a correct one, but I do think it's a viable idea. But correct and viable are meaningless when you're talking about ideas and hypothesis, and speculation. Ok it's better than ST, and ok I agree I have been a bit rash, and a bit of a :devil:

Again thanks for the dialogue, it's been emotional as Vinny Jones once said, but of course in a positive way.:smile:

It's Ok I'm not going to use a resort to authority to justify my position, he's very keen on trying to find the flaws, his motivation is no different from yours, you just have a different way of going about it :smile:

Oh and by wrong he means you have nothing but a theory that is flawed to back up your argument, therefore he thinks since there is no evidence or proof you may be involved in pure philosophy, I'm off work 'til Monday but I'll ask him to read this. He's an amiable fellow, if he thinks he's wrong he's the first to admit it.
 
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  • #57
Schrodinger's Dog said:
considering he feels the current theory is wrong then yes, pretty much I'm sure he would, he's got issues with most accepted facts though, that's his opinion. He's currently at odds with using imaginary numbers and is trying to find a 3d-spin solution without resorting to imaginary numbers, but he's almost given up in spherical polar co-ordinates even with i.

Re forsaking imaginary numbers: see work on Geometric Calculus by Hestenes et al.

For example: http://modelingnts.la.asu.edu/ wm
 
  • #58
wm said:
Re forsaking imaginary numbers: see work on Geometric Calculus by Hestenes et al.

For example: http://modelingnts.la.asu.edu/ wm

Thanks for that I'll have a look :smile:

Your first link doesn't work BTW. Or is it not meant to? Ah I see it's a suggestion my mistake.

Anything quickly accessable?

http://www.mrao.cam.ac.uk/~clifford/introduction/intro/intro.html

http://en.wikipedia.org/wiki/Geometric_algebra

http://citeseer.ist.psu.edu/context/105756/0

Ok got something thanks.:smile:

Lucky I recently researched Imaginary numbers really.
 
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  • #59
There is a somewhat simpler way of geometrizing QM (and eliminating imaginary numbers) than Hestenes', see the article on geometric representations of the density matrix by Havel, Doran and Furuta:
http://www.mrao.cam.ac.uk/~clifford/publications/abstracts/hd_density.html

The above gives two methods. The first, the obvious one, is used in my book. I need to add a reference to the above, as I was unaware of it when I started writing. See chapters 1 and 2 for an easy introduction to the ideas:
http://brannenworks.com/dmaa.pdf
(The above is "easy" in that it builds on what you already know about Pauli and Dirac spinors and all that. Other authors tend to jump off into Clifford algebra land and so end up writing for specialists only.)

The second method discussed in the Havel, Doran & Furuta paper is similar to Hestenes' technique, which is used for spinors, rather than density matrices. And there is also another way of geometrizing the Dirac equation that is discussed very briefly (and in a difficult to understand manner, I think) here:
http://en.wikipedia.org/wiki/Dirac_equation_in_the_algebra_of_physical_space

I think that the above is particularly inelegant. I know it's listed in the literature, but even Hestenes' method is easier and more natural. For methods that involve just spinors (not the density operators Havel, Doran and Furuta used and I use), the incomparable Baylis has an excellent review and comparison article that will explain the reasoning behind the various choices:
http://www.arxiv.org/abs/quant-ph/0202060

I'm trying to get myself motivated to start a wikipedia article on these various methods of geometrizing quantum mechanics. One of the problems with doing this is that the truth is that one has to know a substantial amount of Clifford algebra before any of this makes sense. Another problem is that it seems that ALL the various authors use completely incompatible notation. And a third problem is that there are many many ways of deriving the same thing, (as is the case for any true thing), and everyone seems to prefer different ways of doing the derivations. And finally, while the field has been in play since Hestenes' articles of the early 1980s, so far there is no generally accepted result that has extended anything beyond where QM already has gone.

Carl
 
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  • #60
Thanks I'll show my colleague, he'll probably be interested.
 
  • #61
Hurkyl said:
Not even close. Euclid's postulates are for one specific entity (a Euclidean plane), and they were far from complete.

Dear Mentor,

I studied P.K. Rashevski “Riemann Geometry and tensor analysis” before I finished high school. At the same time I read original papers by N.I. Lobachevski and the Russian translation of J. Boljai. Before writing the post concerned the axiomatic of physical theory, …

Let me explain to you the conceptual content of my disagreement with Vanesch. Vanesch stated that the superposition principle is universally valid physical postulate. However, it is too restrictive and not a physical postulate at all. It is only the inherent feature of the mathematical framework called linear Hilbert space with very restrictive class of operators (transformations):linear operators. The mathematical framework is only the empty arena suitable or not suitable for the specific applications in physics.

In addition, Vanesch discussions of MWI remind me the N.Bohr style of presentation, for example, in the paper “The Quantum Postulate and the recent development of Atomic Theory”, Nature, 121, 580 (1928):
“… the formulation of the quantum theory, it seems, as we shall see, that its essence may be expressed in the so-called quantum postulate, which attributes to any atomic process an essential discontinuity, or rather individuality, completely foreign to the classical theories and symbolized by Plank’s quantum of action.”

As far as non-relativistic CM vs non-relativistic QM is considered, just the opposite is correct. In view of our today empirical knowledge, this definition express only the perfect confusion of the writer.

Forum Rules:”“Posting the same topic across multiple forums or multiple threads is considered spam and is not allowed.”

Vanesch insist to make propaganda of MWI in each session of discussion, does not a matter what it is specifically:’the wave packet description”, “ non-locality” or present one, etc. It is not written in any standard textbook on QM or QFT that MWI is universally valid interpretation of QT. Vanesch propaganda is in contradiction with the Rules of PF.

The self-obvious postulate of the PF is: Don’t confuse kids.

I wish that the future generation of physicists will understand Quantum Physics. Are you also?

Dany.
 
  • #62
To be fair though Anonym, I started it :smile: and was delighted to play discordant antagonist:tongue2: to Vanesche's concerto:smile:
 
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  • #63
Anonym said:
It is not written in any standard textbook on QM or QFT that MWI is universally valid interpretation of QT. Vanesch propaganda is in contradiction with the Rules of PF.

The self-obvious postulate of the PF is: Don’t confuse kids.
But what if some kid asks interpretational questions on QM to which answers are not written in any standard textbook? Should we tell him/her: "Shut up and calculate!"? Or that it is impossible to answer such questions? Or that some possible answers exist but that there is no yet consensus among experts? In the latter case, shouldn't we explain them these possible answers?
 
  • #64
Anonym said:
Let me explain to you the conceptual content of my disagreement with Vanesch. Vanesch stated that the superposition principle is universally valid physical postulate.

No, I didn't state that. I state that *quantum theory* takes as a postulate, the superposition principle. It is its basic principle ! In the same way as GR takes as basic postulate, that there is a pseudo-riemanian spacetime manifold. It is the starting point of the theory.
Starting from this postulate of superposition, the natural mathematical representation is a (projective) hilbert space. In fact, stating that the space of physical states is a (projective) hilbert space, or stating that the superposition principle is supposed to be valid, is the same statement.

However, it is too restrictive and not a physical postulate at all. It is only the inherent feature of the mathematical framework called linear Hilbert space with very restrictive class of operators (transformations):linear operators. The mathematical framework is only the empty arena suitable or not suitable for the specific applications in physics.

... and in quantum theory, it is, BY POSTULATE, the arena in which nature is supposed to act.

In addition, Vanesch discussions of MWI remind me the N.Bohr style of presentation, for example, in the paper “The Quantum Postulate and the recent development of Atomic Theory”, Nature, 121, 580 (1928):
“… the formulation of the quantum theory, it seems, as we shall see, that its essence may be expressed in the so-called quantum postulate, which attributes to any atomic process an essential discontinuity, or rather individuality, completely foreign to the classical theories and symbolized by Plank’s quantum of action.”

As far as non-relativistic CM vs non-relativistic QM is considered, just the opposite is correct. In view of our today empirical knowledge, this definition express only the perfect confusion of the writer.

Well, if my style of discussion is of the level of a N. Bohr article in Nature, I feel in good company :biggrin:

Forum Rules:”“Posting the same topic across multiple forums or multiple threads is considered spam and is not allowed.”

Vanesch insist to make propaganda of MWI in each session of discussion, does not a matter what it is specifically:’the wave packet description”, “ non-locality” or present one, etc. It is not written in any standard textbook on QM or QFT that MWI is universally valid interpretation of QT. Vanesch propaganda is in contradiction with the Rules of PF.

I don't think so. The problem is that in many threads, the interpretational issues come to the foreground, and in many cases, the MWI interpretation sheds some interesting light on the issue. The most interesting light I think is in the case of "non-locality" in the EPR situation, which comes up in many discussions. I think it is allowed to point this out, no? However, MWI is often met with 1) ignorance of what exactly it states, and 2) a strong emotional rejection from the part of some posters. I try to explain to these posters that MWI is NOT the totally crazy idea of a few lunatics, but is taken quite seriously by several people, and I try to point out its advantages in resolving certain issues. As I said, the ONLY objections I know against MWI, are of the emotional kind.

That said, you should acknowledge that I'm not forcing MWI through anybody's throat, I'm just informing people, and try to get them beyond the "emotional rejection" part, which usually doesn't allow them to even understand exactly what MWI is saying. Now, it is true that in doing so, I sometimes point out the evident logical contradictions in the "standard" Copenhagen view, which are nevertheless swallowed without any reflection.

You might also have noticed, if you read my contributions carefully, that I never claim MWI to be "true", but just a conceptual tool to UNDERSTAND quantum theory ; and especially, to understand how certain bizarre predictions of quantum theory come about.

The self-obvious postulate of the PF is: Don’t confuse kids.

I wish that the future generation of physicists will understand Quantum Physics. Are you also?

Yes, and I'm profoundly convinced that taking on an MWI view (amongst others!) helps doing this.
 
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  • #65
Schrodinger's Dog said:
To be fair though Anonym, I started it :smile: and was delighted to play discordant antagonist:tongue2: to Vanesche's concerto:smile:

Indeed, I tried to play second violin but it doesn’t sounds to me that bad. Always an improvement possible. After all, the well time-treated (observer-dependent) counterpoint is the art of fugue all about. I enjoy Vanesch discussions very much. I intend to write a paper with a purpose to demonstrate that more than 40 years ago it was already shown that the M.Born statistical interpretation have no room in quantum mechanical formalism. It is direct consequence of my discussions with Vanesch. According to the standard rules, he should be co-author of that paper. However, I fear even to ask his agreement.

Eventually, the principal postulates are only Global Guidelines in the actual research. Obviously, they altogether are so restrictive that the only adequate formulation of the corresponding Chapter will satisfy all of them simultaneously. Our discussions are around the measurement theory. In his famous discussions with N. Bohr, A. Einstein did not talk about them, but referred to them in his statement “… ob der liebe Gott wurfelt” (Classical Physics). In contrast, N. Bohr invent freely the “new” postulates, but clamed that A. Einstein should not tell to God what to do. His logic seems to me ridiculous. All that similar to Jewish story with Chodesh Chodashim. Obviously, no physicist is allowed to enter that room by definition. However, if you are curious enough, you may travel to Idfu temple in Egypt and you will get an idea adequate for all practical purposes.

P.S. I like old music. How I find a good piece? Let say 500 years old. I look if an author is Anonym.
 
  • #66
Anonym said:
Indeed, I tried to play second violin but it doesn’t sounds to me that bad. Always an improvement possible. After all, the well time-treated (observer-dependent) counterpoint is the art of fugue all about. I enjoy Vanesch discussions very much. I intend to write a paper with a purpose to demonstrate that more than 40 years ago it was already shown that the M.Born statistical interpretation have no room in quantum mechanical formalism. It is direct consequence of my discussions with Vanesch. According to the standard rules, he should be co-author of that paper. However, I fear even to ask his agreement.

Eventually, the principal postulates are only Global Guidelines in the actual research. Obviously, they altogether are so restrictive that the only adequate formulation of the corresponding Chapter will satisfy all of them simultaneously. Our discussions are around the measurement theory. In his famous discussions with N. Bohr, A. Einstein did not talk about them, but referred to them in his statement “… ob der liebe Gott wurfelt” (Classical Physics). In contrast, N. Bohr invent freely the “new” postulates, but clamed that A. Einstein should not tell to God what to do. His logic seems to me ridiculous. All that similar to Jewish story with Chodesh Chodashim. Obviously, no physicist is allowed to enter that room by definition. However, if you are curious enough, you may travel to Idfu temple in Egypt and you will get an idea adequate for all practical purposes.

P.S. I like old music. How I find a good piece? Let say 500 years old. I look if an author is Anonym.

You should include this discussion in your paper, if you ask me it's a very clear way of showing what MWI attempts to show, cut the chaff out, ie my posts though :biggrin:
 
  • #67
Anonym said:
Vanesch:” QFT is not an interpretation of quantum theory, it is the application of quantum theory to a specific classical model (classical fields). As such, all interpretational issues remain with QFT in the same way as they remain with other applications of quantum theory.”

Allday:” One "law" that you can keep in mind is that quantum objects travel as waves and interact as particles”.

It is follow deterministically from your discussion with me in the Particle-Wave duality and Hamilton-Jacobi equation session that

There is no legitimation for M.Born statistical interpretation any more and it may be removed from the formalism of the Quantum Theory. Quantum Theory is the local field theory of the massive waves. No interpretation required.

I would welcome some elaboration of this last paragraph:

1. On what grounds is the Born statistical interpretation no longer legitimate?

2. How is ''collapse'' handled in QFT?

3. ''No interpretation required'' seems (to me) to be the Holy Grail of every theorist. Please elaborate; eg, on the ontology (''elements of reality'') associated with your view.

Thanks, wm
 

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