Many Worlds Interpretation and act of measuring

[bhobba]

After being AFK for a while, I am just going to leave this new paper here: http://arxiv.org/abs/1504.01063 it explains what is so wrong with the current approach to probabilities in MWI

Gave it a quick sqizz - here is one bit:
'But as Peter Lewis points out, ‘to say that the state has branches is just to say that it can be written as a sum of more-or-less independent terms, where each term is taken as a description of a state of affairs ... so the state of affairs is the branch ... it makes no sense to conceive of the same state of affairs in a different branch.’

and

'The Relevance-Limiting Thesis: It is never epistemically rational for an agent who learns only self-locating information to respond by altering a non-self-locating credence'

If anyone can explain it to me be my guest.

Probabilities in MW is simple - they define it as per decision theory which is a variant of Bayesen probability. It's this - the probability, P, of something is that a rational agent is willing to bet on it at 1/P to 1 odds (see page 132 of Wallaces text). Nothing hard about it. Its widely used by Actuaries, for example. If there was anything the mater with it those guys would have found it long ago.

MW is conceptually simple. After decoherence you have a mixed state ∑ pi |bi><bi| and each |bi><bi| is interpreted as a separate world. Nothing hard about it.

If MW is so wrong then it should be explainable, clearly and simply, why each |bi><bi| can't be interpreted as a separate world. One issue is the factorisation problem - agreed - but that requires more work. Another is how do we explain the randomness of the environment in decoherence models - again more work needs to be done. These statements that MW has definitely been disproved is, to be blunt, sensationalism of dubious value.

Thanks
Bill

 

[RUTA]

Yes, I understand that you are denying it. But it is logically inconsistent of you.

There's no logical reason preventing 1 million people, each having flipped a coin 20 million times, from concluding that the probability of heads is 0.5. It is merely an assumption about the nature of reality (not logical necessity) to claim that some of those people will necessarily conclude the probability is other than 0.5. Using your assumption, one would have to be very skeptical about the many probabilistic formulae we claim to have tested empirically. Using my assumption, it is safe to conclude that empirical deviations from a probabilistic formula actually discredit the formula and aren't merely statistical anomalies.

 

[bhobba]

There's no logical reason preventing 1 million people, each having flipped a coin 20 million times, from concluding that the probability of heads is 0.5. It is merely an assumption about the nature of reality (not logical necessity) to claim that some of those people will necessarily conclude the probability is other than 0.5. Using your assumption, one would have to be very skeptical about the many probabilistic formulae we claim to have tested empirically. Using my assumption, it is safe to conclude that empirical deviations from a probabilistic formula actually discredit the formula and aren't merely statistical anomalies.

Probabilities are defined rigorously by the Kolmogorov axioms. It is well known measuring probabilities is problematical because the law of large numbers converges only almost surely. But we can always put bounds on it that can be reduced to well below what any rational person would accept as being for all practical purposes zero probability.

Thanks
Bill

 

[RUTA]

Probabilities are defined rigorously by the Kolmogorov axioms. It is well known measuring probabilities is problematical because the law of large numbers converges only almost surely. But we can always put bounds on it that can be reduced to well below what any rational person would accept as being for all practical purposes zero probability.

Thanks
Bill

This says nothing about the way the probabilities are instantiated in reality. That requires an additional assumption.

 

[atyy]

This says nothing about the way the probabilities are instantiated in reality. That requires an additional assumption.

Are you and stevendaryl referring to the section on the Principal Principle in Adlam's paper (http://arxiv.org/abs/1504.01063, section IV.B, p15)?

 

[bhobba]

This says nothing about the way the probabilities are instantiated in reality. That requires an additional assumption.

Yes. Application of Kolmogorov's axioms requires some 'reasonableness' assumptions to apply it. They are usually so obvious books like Feller that detail applied probability don't actually state them - you pick them up by doing problems.

Thanks
Bill

 

[stevendaryl]

Are you and stevendaryl referring to the section on the Principal Principle in Adlam's paper (http://arxiv.org/abs/1504.01063, section IV.B, p15)?

I agree with points 1-3 in the list at the end of page 15, beginning of page 16. However, what I disagree with is an additional assumption she makes later:

...we require that the reason it is rational to do this [make credence a function of probability] is that having such credences is a good way of arriving at true beliefs

We might wish for that to be true, but we can't require it. As I said, if you are unlucky enough to get a run of 20 (or 20,000) heads in a row while tossing coins, then you will come to a false conclusion about whether you have a fair coin. Equating relative frequencies with probabilities is not a guaranteed way of arriving at the truth. The best you can say is that you probably will arrive at something close to the truth. I don't see that MWI makes things any worse.

I agree that there is something a little mysterious and unsatisfactory about the accounts of probability within MWI, but in my opinion, the problems reflect problems with making sense of probabilities, in any case.

Presumably, a Von Neumann-style "collapse" interpretation has no conceptual difficulties with probabilities. You perform a measurement, and you get one result out of a set of possibilities with a certain weight on the possibilities. This weight has the empirical content that if you repeat the measurement many times under identical conditions, the relative frequencies will approach the weight. That sounds unmysterious.

However, if you conceptually replace a single "run" of the universe by an ensemble of infinitely many independent runs, then this ensemble will include all possible finitely specifiable outcomes. Even though the evolution of a single system in the ensemble is nondeterministic (at least if we treat the "index" of individual systems as irrelevant), the evolution of the entire ensemble is deterministic: every possible outcome happens. The ensemble model, with deterministic evolution, is in some sense equivalent to the original nondeterministic single-system model. I can't see how there can be problems with the concept of probability that apply to the one that doesn't also apply to the other in a transformed way.

Of course, MWI is not simply an ensemble version of Copenhagen, because there are interference effects and because of the basis problem, and so forth. But conceptually, it seems to me that the problems with probability are not unique to MWI.

 

[RUTA]

Are you and stevendaryl referring to the section on the Principal Principle in Adlam's paper (http://arxiv.org/abs/1504.01063, section IV.B, p15)?

I'm pointing out a (naïve) issue with checking a universal probability. For example, if half the civilizations in the universe always found heads when flipping a coin and the other half always found tails, the universal probability would be 0.5 for heads/tails, but no civilization would discover it. There are assumptions you have to make as to how a probabilistic rule is instantiated in reality. My assumption is that every civilization will deduce the correct universal probability. That's all I'm saying. The reason it bears on Many Worlds is that, apparently, and I'm waiting for someone to clarify this for me, the simple counting of branches for a frequentist view of MW produces "too many" of the branches deducing empirically the wrong universal probability. This spawned a "subjectivist" view of probability in MW (per Deutsch and Wallace) which is predicated on inconsistent assumptions per Dawid and Thebault (http://philsci-archive.pitt.edu/9542/1/Decoherence_Archive.pdf).

 

[bhobba]

Are you and stevendaryl referring to the section on the Principal Principle in Adlam's paper (http://arxiv.org/abs/1504.01063, section IV.B, p15)?

If you can understand that paper you are a better man than me Gunga Din.

Thanks
Bill

 

[bhobba]

This spawned a "subjectivist" view of probability in MW (per Deutsch and Wallace) which is predicated on inconsistent assumptions per Dawid and Thebault (http://philsci-archive.pitt.edu/9542/1/Decoherence_Archive.pdf).

Can't agree with that one. Actuaries for example make extensive use of the decision theory view of probability.

I believe probabilities are a tricky issue when analysed carefully - but the modern axiomatic view resolves them.

Thanks
Bill

 

[RUTA]

If you can understand that paper you are a better man than me Gunga Din.

Thanks
Bill

I didn't read her paper, but I read the one by Dawid and Thebault http://philsci-archive.pitt.edu/9542/1/Decoherence_Archive.pdf and its arguments looked sound. I don't study MW (for or against), so I was hoping someone here would clarify/correct my naïve understanding of the Kent --> Deutsch/Wallace --> Dawid/Thebault chain of argument posted in #158.

 

[RUTA]

Can't agree with that one. Actuaries for example make extensive use of the decision theory view of probability.

I believe probabilities are a tricky issue when analysed carefully - but the modern axiomatic view resolves them.

Thanks
Bill

The term "subjectivist" is the language in Dawid's paper with a footnote that it should be "epistemic," but ... . So do you disagree with the "subjectivist" approach of Deutsch/Wallace? Or do you agree with that and disagree with Dawid's arguments against it?

 

[atyy]

I'm pointing out a (naïve) issue with checking a universal probability. For example, if half the civilizations in the universe always found heads when flipping a coin and the other half always found tails, the universal probability would be 0.5 for heads/tails, but no civilization would discover it. There are assumptions you have to make as to how a probabilistic rule is instantiated in reality. My assumption is that every civilization will deduce the correct universal probability. That's all I'm saying. The reason it bears on Many Worlds is that, apparently, and I'm waiting for someone to clarify this for me, the simple counting of branches for a frequentist view of MW produces "too many" of the branches deducing empirically the wrong universal probability. This spawned a "subjectivist" view of probability in MW (per Deutsch and Wallace) which is predicated on inconsistent assumptions per Dawid and Thebault (http://philsci-archive.pitt.edu/9542/1/Decoherence_Archive.pdf).

I'll read Dawid and Thebault, but in the mean time, have you seen http://philsci-archive.pitt.edu/4222/ ?

 

[bhobba]

The term "subjectivist" is the language in Dawid's paper with a footnote that it should be "epistemic," but ... . So do you disagree with the "subjectivist" approach of Deutsch/Wallace? Or do you agree with that and disagree with Dawid's arguments against it?

Ok - first my own view. I am not into Baysian, subjectivist stuff - for me probability is simply Kolmogorovs axioms and its frequentest implementation via the law of large numbers. I find MW simply too weird to accept. I hold to the ignorance ensemble interpretation.

That said Bayesian views - either the decision theoretic version or the Cox axioms version, and there are probably others as well, all conform to Kolmogorov's axioms so are equally as valid. Because of that it's impossible for them to have logical fault. I think people that attack it on those grounds are simply doing philosophical sophistry for philosophical sophistry's sake. When I read http://arxiv.org/abs/1504.01063 I thought - this isn't science - its just philosophical waffle. The paper you mentioned is another matter - I would need to look at it a bit more carefully.

Thanks
Bill

 

[atyy]

That said Bayesian views - either the decision theoretic version or the Cox axioms version, and there are probably others as well, all conform to Kolmogorov's axioms so are equally as valid. Because of that it's impossible for them to have logical fault. I think people that attack it on those grounds are simply doing philosophical sophistry for philosophical sophistry's sake. When I read http://arxiv.org/abs/1504.01063 I thought - this isn't science - its just philosophical waffle. The paper you mentioned is another matter - I would need to look at it a bit more carefully.

The Bayesian view - say de Finetti's - is beautifully coherent - the part that makes it very hard to know whether the Deutsch-Wallace version of MWI is correct is that they take the decision theory without the Bayesian part - because they want to derive probability without the Bayesian axioms. Eg. Wallace, http://arxiv.org/abs/quant-ph/9906015: "all the practical consequences of such predictions follow from the remaining, non-probabilistic, axioms of quantum theory, together with the non-probabilistic part of classical decision theory." !

BTW, I'm a frequentist if you are wondering, because I prefer being incoherent :p

 

[bhobba]

that they take the decision theory without the Bayesian part

They are all logically equivalent. Like I said Actuaries have been using decision theory for years - its simply another way of looking at probability.

Thanks
Bill

 

[atyy]

They are all logically equivalent. Like I said Actuaries have been using decision theory for years - its simply another way of looking at probability.

No, they are not - if you look at Deustch - he is saying he is only taking the decision theory part without the probability - so what he is doing is not what actuaries have been doing for years.

One way to see that it is not the same is that Wallace's defence of Deutsch depends on MWI. As far as I know, actuaries do not assume MWI.

Wallace, http://arxiv.org/abs/quant-ph/0312157: "His work has not so far met with wide acceptance, perhaps in part because it does not make it at all obvious that the Everett interpretation is central (and his proof manifestly fails without that assumption)."

 

[bhobba]

No, they are not - if you look at Deustch - he is saying he is only taking the decision theory part without the probability

That is NOT what Wallace says. He specifically defines it as I said before - and in his book - page 472 - proves it is equivalent to Bayesian probability - Theorem 4 - Diachtonic Representation Theorem.

Thanks
Bill

 

[atyy]

That is NOT what Wallace says. He specifically defines it as I said before - and in his book - page 472 - proves it is equivalent to Bayesian probability - Theorem 4 - Diachtonic Representation Theorem.

Yes, Wallace intends to show that decision theory + MWI gives Bayesian probability - so it is not the same as what actuaries have been doing - actuaries do not assume MWI. They assume decision theory + Bayesian theory.

 

[bhobba]

Yes, Wallace intends to show that decision theory + MWI gives Bayesian probability - so it is not the same as what actuaries have been doing - actuaries do not assume MWI. They assume decision theory + Bayesian theory.

No.

From the axioms of decision theory Theroem 4 proves the link. Its got nothing to do with MW - only decision theory axioms.

It's simply a different view of probability from different axioms.

Thanks
Bill

 

[atyy]

No.

From the axioms of decision theory Theroem 4 proves the link. Its got nothing to do with MW - only decision theory axioms.

It's simply a different view of probability from different axioms.

Well, at some step there is something in Wallace's understanding of the Deustch proof that requires MWI. So while I accept that there are decision theoretic axioms that give rise to probability, I do not believe that is what Deustch-Wallace are doing.

Wallace, http://arxiv.org/abs/quant-ph/0312157: "His work has not so far met with wide acceptance, perhaps in part because it does not make it at all obvious that the Everett interpretation is central (and his proof manifestly fails without that assumption)."

 

[bhobba]

Wallace, http://arxiv.org/abs/quant-ph/0312157: "His work has not so far met with wide acceptance, perhaps in part because it does not make it at all obvious that the Everett interpretation is central (and his proof manifestly fails without that assumption)."

My knowledge of the detail of MW comes from Wallace's book - not Deutch - so I don't know his arguments.

But for me Wallace looks sound - although, as I have said before, when I went through his arguments, I thought it simply was Gleason in disguise because contextuality doesn't quite work - indeed it's encoded in the non-contextuality theorem on page 475.

Thanks
Bill

 

[atyy]

My knowledge of the detail of MW comes from Wallace's book - not Deutch - so I don't know his arguments.

But for me Wallace looks sound - although, as I have said before, when I went through his arguments, I thought it simply was Gleason in disguise because contextuality doesn't quite work - indeed it's encoded in the non-contextuality theorem on page 475.

OK, I was thinking of the earlier Wallace argument. I don't have access to his book - does http://arxiv.org/abs/0906.2718 look close enough?

 

[bhobba]

OK, I was thinking of the earlier Wallace argument. I don't have access to his book - does http://arxiv.org/abs/0906.2718 look close enough?

Looks about the same - including interesting comments about Gleason.

Thanks
Bill

 

[RUTA]

I'll read Dawid and Thebault, but in the mean time, have you seen http://philsci-archive.pitt.edu/4222/ ?

No, I haven't read that or any Deutsch or Wallace. I was hoping you guys could save me having to do that. I started reading this link and see that it's 47 pp, so it would take me awhile to get through it. Have you read it? Can you summarize anything?

 

[atyy]

No, I haven't read that or any Deutsch or Wallace. I was hoping you guys could save me having to do that. I started reading this link and see that it's 47 pp, so it would take me awhile to get through it. Have you read it? Can you summarize anything?

Yes, everyone's view seems to make sense on a first pass - but if you start asking whether you have missed some subtlety by trying to find a robust core to the argument, that answer is hard to find, because everyone's argument is different and seems incompatible.

Wallace summarizes the situation in http://arxiv.org/abs/0712.0149.

"It is useful to split this problem in two:

The Incoherence Problem: In a deterministic theory where we can have perfect knowledge of the details of the branching process, how can it even make sense to assign probabilities to outcomes?

The Quantitative Problem: Even if it does make sense to assign probabilities to outcomes, why should they be the probabilities given by the Born rule?"

Regarding the incoherence problem, he writes " The Subjective Uncertainty Program aims to establish that probability really, literally, makes sense in the Everett universe: that is, that an agent who knows for certain that he is about to undergo branching is nonetheless justified in being uncertain about what to expect. ... If the Subjective Uncertainty program can be made to work, it avoids the epistemological problem of the Fission Program, for it aims to recover the quantum algorithm itself (and not just to account for its empirical success.) It remains controversial, however, whether subjective uncertainty really makes sense. For further discussion of subjective uncertainty and identity across branching, see Greaves (2004), Saunders and Wallace (2007), Wallace (2006a) and Lewis (2007)."

Regarding the quantitative problem, he says "The third, and most recent, strategy has no real classical analogue (though it has some connections with the ‘classical’ program in philosophy of probability, which aims to derive probability from symmetry). This third strategy aims to derive the principle that weight=probability from considering the constraints upon rational action of agents living in an Everettian universe. It was initially proposed by Deutsch (1999), who presented what he claimed to be a by Barnum et al (2000), and defended by Wallace (2003b). Subsequently, I have presented various expansions and developments on the proof (Wallace 2007,2006c), and Zurek (2003b, 2005) has presented another variant of it. It remains a subject of controversy whether or not these ‘proofs’ indeed prove what they set out to prove."

 

[Rodrigo Cesar]

Why not accept that no one understands quantum physics and move on ? rather than create theories that don't make any sense... no math will solve this, each time someone tries to solve the problems of quantum physics more problems appear, srsly.. Quantum physics is beyond our logic..understanding classical physics is enough!

 

[bhobba]

rather than create theories that don't make any sense... no math will solve this,

Its the exact opposite - mathematically its very beautiful and makes a lot of sense. Its just to many, including me, it's too weird. But weirdness is purely a personal reaction - nothing to do if its true or not.

BTW its a myth that no-one understands QM. We certainly understand it these days eg:
http://arxiv.org/pdf/quant-ph/0101012.pdf

What it means, what are its basic primitives, what it explains and what it doesn't - that's what this interpretation stuff is about.

Thanks
Bill

 

[Rodrigo Cesar]

In math makes sense, but in reality is very tasteless, we must have a balance between both

 

[DennisN]

In math makes sense, but in reality is very tasteless, we must have a balance between both

Why? Science is not like art, literature, architecture etc (and "tasteless" is an opinion, which actually is completely irrelevant). If the mathematics and the models work, they work, that is the only thing that matters in the end. If you want art instead, you go to an art museum . Here's what Feynman had to say about it (with toungue-in-cheek):


Edit: Another way to put it is basically like this: In science, if we are to choose between a beautiful inaccurate theory and an ugly accurate theory, we choose the ugly one, not because it is ugly but because it is accurate.

 

[atyy]

Why? Science is not like art, literature, architecture etc . If the mathematics and the models work, they work, that is the only thing that matters in the end. If you want art instead, you go to an art museum . Here's what Feynman had to say about it (with toungue-in-cheek):

Rubbish! It wasn't tongue in cheek. Not all universes have observers, however, since recoherence is inevitable, some observers will end up in another universe.

 

[Quantumental]

This is a nice take down of the decision-theoretic approach of Wallace. The author even offers an attempt to solving the problem: arxiv.org/pdf/0808.2415

 

[bhobba]

Why? Science is not like art, literature, architecture etc (and "tasteless" is an opinion, which actually is completely irrelevant).

Exactly. I find it too weird for my tastes - but that means diddley squat. The only thing that matters is correspondence with experiment.

Thanks
Bill

 

[bhobba]

This is a nice take down of the decision-theoretic approach of Wallace. The author even offers an attempt to solving the problem: arxiv.org/pdf/0808.2415

Can you give a précis of its argument in simple terms? The last paper you posted I couldn't make sense of - it looked like philosophical goobly gook to me.

Thanks
Bill

 

[bhobba]

Rubbish! It wasn't tongue in cheek. Not all universes have observers, however, since recoherence is inevitable, some observers will end up in another universe.

Bearing in mind that in MW an observation occurs when decoherence happens what universe will not have observers ie what universe will not allow decoherence?

Thanks
Bill

 

[Rajkovic]

when will we have a final position on MWI, if it is correct or not?

 

[DennisN]

Exactly. I find it too weird for my tastes - but that means diddley squat. The only thing that matters is correspondence with experiment.

Just to clarify, my reply was actually a general reply to post #177 and #179 by the OP, which I interpreted to be about quantum physics in general. Regarding MWI I feel the same as you, but that also means diddley squat (I also have some more scientific issues with MWI in general, but I'm not keen to go into those at the moment; if I would, I'd like to be more thorough than I could be a the moment. AND have more knowledge than I have at the moment. Maybe some other time ).

 

[bhobba]

when will we have a final position on MWI, if it is correct or not?

Of course its correct. Disproving would be big news. Nothing here has done that.

Thanks
Bill

 

[Rajkovic]

Ok, but, what's the best interpretation of MWI? I know there are many..could you explain to me ?

 

[bhobba]

Ok, but, what's the best interpretation of MWI? I know there are many..can you explain to me ?

I only know one - Wallace's as detailed in his book on it:
https://www.amazon.com/dp/0198707541/?tag=pfamazon01-20

But if this type of interpretation appeals then take a look at Consistent Histories:
http://quantum.phys.cmu.edu/CHS/histories.html

It's described by Gell-Mann as many worlds without the many worlds. Also, again according to Gell-Mann, Feynman was very positive towards it, sitting in the back of seminars and asking quite penetrating questions. Basically its the stochastic theory of histories - which are basically a coarse grained sequence of worlds in MW parlance - but in Consistent Histories you only have one.

I like Consistent Histories - my only objection is for me it looks like defining your way out of problems rather than facing them head on.

Thanks
Bill

 

[Quantumental]

Of course its correct. Disproving would be big news. Nothing here has done that.

I always get the feeling that you really believe MWI, but don't want to accept the implications of such a belief ;p
Saying "of course it's correct", is a bit weird. It's correct like every other interpretation is correct, but then again all interpretations has scientific and technical difficulties that make them incorrect.

Nearly all refutations of David Wallace's decision-theoretic programme will include what you call "philosophcal goobly gook", simply because the entire decision-theoretic approach is hopelessly philosophical and outside the realm of science itself. So in order to take it apart, you have to go down to it's level and dissect it. This is also why it is borderline impossible to cook it down to a short paragraph.
There is a simple argument put forth by David Albert called the "fatness measure", it's summarized here: https://books.google.com/books?id=V9yQrUQW6O0C&pg=PA181&redir_esc=y#v=onepage&q&f=false

There are so many arguments put forth against the decision theoretic approach that is a lot more solid than the derivation itself, so to me the Born Rule issue is wholly unsolved. There are other attempts, but all of those have pretty much been shown to be circular/flawed in some fatal way. Which is why even amongst the proponents of MWI, they do not agree at all.

Couple this with the factorization problem and other issues mentioned (by you too Bhobba), I do think it's fair to say that MWI fares no better than any other interpretation, one might even argue that it's one of the interpretations that is pretty bad off. The idea of just taking the wavefunction and then saying "every outcome is real" sounds very elegant and simple, but then you realize that's not what MWI is and what MWi does not work with current understanding of physics and philosophy, suddenly it's not so elegant anymore. I would also suggest you read Jeffrey Barretts recent paper where he defends the emperical adequacy of pure wave mechanics (pure Everett). http://www.socsci.uci.edu/~jabarret/bio/publications/everett4.pdf He also picks apart Wallace's approach quite well in this article by showing how much additional "stuff" and assumptions Wallace add to quantum mechanics in order to defend his "emergence" argument.

 

[bhobba]

Nearly all refutations of David Wallace's decision-theoretic programme will include what you call "philosophcal goobly gook", simply because the entire decision-theoretic approach is hopelessly philosophical and outside the realm of science itself.

That's exactly the issue I have. Decision Theory is a well developed area of math used in a number of mathematical areas such as Actuarial Science. It has a number of key theorems from its axioms - one being that its notion of probability, which I gave previously, is equivalent to the Kolmogorov axioms. That being the case its a perfectly valid basis as an interpretation of probability in QM, just like Bayesian or frequentest, or even just using the Kolmogorov axioms themselves.

This philosophy stuff leaves me cold because no agreement is ever reached. Previous things like Kant's idea that Euclidean geometry was a-priori true proved a crock - in fact it was clear, logical, mathematical reasoning that proved it so - not philosophical mumbo jumbo.

Thanks
Bill

 

[Rodrigo Cesar]

maybe in another universe I love this theory lol

 

[julcab12]

Its the exact opposite - mathematically its very beautiful and makes a lot of sense. Its just to many, including me, it's too weird. But weirdness is purely a personal reaction - nothing to do if its true or not.

... Well. In QM math is deliberate and literal -- "what you see is what you get. It appears to be random - Let's make use of the randomness and create probability solutions that is mathematically beautiful. -- It offers prediction-- Ok, fair enough. BUT I'm always reminded that any interpretation in QM are dynamic consequence and not categorized as physical theory. In the classical view. We deal weirdness with caution. We don't take phenomenon's very literal and construct something that is not limited to that axiom like the usual QM does (Who could blame them. They don't have a choice anyways -- We can't make anything cohesive about randomness/multiplicity but view and used it as literal).

... I respect optical theorem in the basis of unitary or some evolution operator that is time dependent including the weird things that time brings to the table. I view multiplicity as optical phenomenon or some sort of false image and respect very much unitarity. Why it looks random/multiple? We really don't know so the simplest way is to take it literal. Until now we only took this paradigm to make probabilistic predictions and not what it really is. IMO. The field breaks the pointer state allowing it to appear as multiple false images/pointers or time slices in a 1 Hilbert space/ 1 universe.

 

[bhobba]

BUT I'm always reminded that any interpretation in QM are dynamic consequence and not categorized as physical theory.

Come again. An interpretation is a physical theory.

and not what it really is. IMO.

That's the precise problem. In QM we have far too much of this 'what it really is' and 'IMHO'. Science isn't concerned with such. For example some believe the math literally is the reality. Its purely philosophical mumbo jumbo believing or refuting such a position. We all do it - but its not science.

Thanks
Bill

 

[julcab12]

Come again. An interpretation is a physical theory.Bill

"Interpretations of quantum mechanics aren't physical theories. There is no testable prediction of the MWI, for example, that would allow us to falsify it (except in the trivial sense that we could falsify quantum mechanics in general, which would also falsify the CI and every other interpretation).

That's the precise problem. In QM we have far too much of this 'what it really is' and 'IMHO'. Science isn't concerned with such. For example some believe the math literally is the reality. Its purely philosophical mumbo jumbo believing or refuting such a position. We all do it - but its not science.

Not really my intention. If you've read my point. I'm a realist. "what it really is" -- in all honestly, is that we really tried to know what it is exactly. That's what it meant by interpretation in QM -- no added baggage. My version of 'IMO' is conducive to real events and not a subjective whatnots. Literal viewpoint is not always the go to in nature simply because we've seen similar events that happens naturally and has natural explanations. If you appeared to me as multiple bhobba. I don't simply look at you as bhobba in a multiple version in a multiple worlds but i have to look also "WHAT MAKES YOU APPEAR THAT WAY'. Ins't that a legit question? This is exactly how we evaluate events in reality.

 

[bhobba]

"Interpretations of quantum mechanics aren't physical theories. There is no testable prediction of the MWI, for example, that would allow us to falsify it

Their is no requirement for all aspects of a theory to be falsifiable.

Not really my intention. If you've read my point. I'm a realist. "what it really is" -- in all honestly, is that we really tried to know what it is exactly.

That's exactly why it a useless criteria. What some accept as 'it is exactly' varies widely eg Penrose believes the math literally is what it is exactly. You probably don't. But in supporting your position you will find its philosophical discourse, and, as I have pointed out innumerable times, that discipline never reaches any conclusions accepted as 'true' like science does.

Thanks
Bill

 

[Quantumental]

Ok let's move the discussion (temporarily at least) away from the probabilities issues since it's so heavily loaded with philosophy and instead move over to the ontological issues of the factorization issue. Why isn't his sufficient enough to disuade you from thinking that MWI is a solid interpretation?

 

[bhobba]

Why isn't his sufficient enough to disuade you from thinking that MWI is a solid interpretation?

Because it hasn't been proven to be fatal to the theory as I have explained many many times eg that paper claiming nothing happens in MW needs to have a bit of a look at spontaneous emission and what causes that.

It has been thrashed out innumerable times in many threads - no need to do it again. And I will not be drawn into another long winded thread about it that goes nowhere.

Thanks
Bill

 

[julcab12]

Ok let's move the discussion (temporarily at least) away from the probabilities issues since it's so heavily loaded with philosophy and instead move over to the ontological issues of the factorization issue. Why isn't his sufficient enough to disuade you from thinking that MWI is a solid interpretation?

.. Depends on how you evaluate each problems which often leads to circular. If it is viewed as direct postulate or ontological approach (universally). MWI has the advantage.