Quantum Interpretation Poll (2011)

In summary, the conversation discusses an annual quantum interpretation poll where one can vote for their preferred interpretation of reality. The poll is missing the consistent histories interpretation and does not have a way to specify details for "other". The thermal interpretation of quantum mechanics is brought up and the speaker provides links to further information on this interpretation, including its benefits and its compatibility with classical thermodynamics. The thermal interpretation is based on the observation that quantum mechanics predicts classical thermodynamics and takes as its ontological basis the states occurring in statistical mechanics. The thermal interpretation also addresses the issue of uncertainty in quantum mechanics and defines a surface ontology and a deeper ontology.

Which Quantum Interpretation do you think is correct?

  • Copenhagen Interpretation

    Votes: 34 22.7%
  • GRW ( Spontaneous Collapse )

    Votes: 2 1.3%
  • Consciousness induced Collapse

    Votes: 11 7.3%
  • Stochastic Mechanics

    Votes: 3 2.0%
  • Transactional Interpretation

    Votes: 4 2.7%
  • Many Worlds ( With splitting of worlds )

    Votes: 12 8.0%
  • Everettian MWI (Decoherence)

    Votes: 18 12.0%
  • de-Broglie Bohm interpretation

    Votes: 17 11.3%
  • Some other deterministic hidden variables

    Votes: 15 10.0%
  • Ensemble interpretation

    Votes: 13 8.7%
  • Other (please specify below)

    Votes: 21 14.0%

  • Total voters
    150
  • #211
To Ken G: Your reply "In short: you have saying the "measurement problem" reduces to "why is information conserved." A useful contribution to be sure-- but no kind of resolution, just a different way to frame the question. And each interpretation that attempts to resolve the measurement problem will also have a different, and equally contentious, way of saying why information is conserved." sounds like your saying that any interpretation of the measurement problem ( which is essentially an interpretation of quantum mechanics) must inturn have an underpinning itself. You're saying that any interpretation must have an underlying interpretation, ad infinitum. The point is that the interpretation is the physicist's opinion of what the underlying conceptual basis of quantum mechanics is. Most physicists would claim that there is no way of empirically testing the difference between one interpretation of quantum mechanics and another (unless one interpretation is seriously flawed). However, this notion might come to pass if there is one day an empirical evidence set which is capeable of distinguishing one interpretation. Let me tell you why I think it is the information interp. Because of the difference in the capeabilities of information and "matter". Information can be transferred superluminally, whereas matter cannot. Why is information potentially FASTER than matter. Is it because information is more fundamental? That is my position, but for now it is only an opinion, like all of quantum interpretation.
 
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  • #212
To Rap: Forget about Wigner and his useless friends. The only validity of the "orthodox interpretation" due to Wigner and Von Neumann is the point that any modification of the preparation , which is undertaken by the scientist, is done so by "irrational" means. It requires a choice by the scientist, and so we have the free will debate and a debate about what the human mind is. Otherwise, this idea about conciousness collapsing the wavefunction (reducing the state description) is plain wrong, and it is one of the interpretations which does have empirical counterexample. If two scientists observe the same experiment, there is no way of the preparation being different for the two perspectives. The system IS objective to both scientists and so the description is identical for both, the description which is appropriate to the preparation.
The counterexample I usually consider is the ZWM study(Mandel 1991) and others like it where the distinguishing information of the preparation determines the outcome of the experiment. The outcome is specifically an interference effect which requires indistinguishability. The experiment has two possible preparations, one where there is distinguishing information (no interference) and one without (interference). It is shown that the interference depends upon the non-presence of IN PRINCIPLE KNOWABILITY of the optical pathways, and it therefore does not in any way depend upon the KNOWABILITY or KNOWLEDGE OF. In other words, no one has to actually know the distinguishing information, it need only be in principle POSSIBLE for such knowledge (from measurements) to be gained in order to negate the interference. So actual knowledge of, conciousness of the observer, is circumvented in this experiment and the collapse still takes place.
 
  • #213
al onestone said:
You're saying that any interpretation must have an underlying interpretation, ad infinitum.
I'm not saying that, I'm saying that the goal of an interpretation is different from the goal of a theory. Theories make predictions, and unify a bunch of different observations under a single conceptual framework, using a simple set of postulates that it does not attempt to justify as reasonable. The latter is the job of an interpretation. Saying that measurements come out as they do because information is conserved is an interpretation, so it is overstating the case to claim that it is solving the problem.

The way to solve the problem is not to find another interpretation to "underpin" one interpretation, for an interpretation that underpins another interpretation is still just another interpretation. Instead, what could underpin an interpretation of one theory is a new theory. The new theory must predict things the old theory does not, or else it is not a new theory, and experimental confirmation of the new predictions then "underpin" the old interpretation of the old theory-- we find the old interpretation to be superior because it connects with the new theory that is experimentally demonstrated to be a better theory. But without that, we cannot say a problem is "solved", we can only suggest a potentially important path for solving the problem.

The point is that the interpretation is the physicist's opinion of what the underlying conceptual basis of quantum mechanics is.
Yes, I agree, and I think conservation of information provides an interesting such opinion. But to claim that it is a solution, and not just an alternative, requires a new theory that makes different predictions, or else it is indeed just another competing interpretation with no particular empirical advantage.

Let me tell you why I think it is the information interp. Because of the difference in the capeabilities of information and "matter". Information can be transferred superluminally, whereas matter cannot. Why is information potentially FASTER than matter. Is it because information is more fundamental? That is my position, but for now it is only an opinion, like all of quantum interpretation.
Yes, I agree that each person holds a different view for many good reasons, and the important thing is to understand all the views because we never know where the next great insight will come from, which leads to that new theory with empirical support. I agree that information is more fundamental, because it makes a more explicit connection with the demonstrably true fact that physics happens in the head of a physicist, and that is also where information happens.
 
  • #214
al onestone said:
In other words, no one has to actually know the distinguishing information, it need only be in principle POSSIBLE for such knowledge (from measurements) to be gained in order to negate the interference. So actual knowledge of, conciousness of the observer, is circumvented in this experiment and the collapse still takes place.
But someone does have to know how the experiment came out, and they have to know how the experiment was set up, so that is simply equivalent to conscious collapse. Physics is still done by the physicist, there's just no escaping that raw fact.
 
  • #215
I know this is an old poll, but I feel like interjecting, stating that I like the many observers interpretation for one reason or another.
 
  • #216
Rap said:
The role of measurement is fundamental in QM and an information approach I think is just as fundamental.
...
Any entity (robotic or human) which is carrying out QM calculations will modify its description of a system as new information becomes availiable. The error that some people make is that they believe that the description (e.g. the wave function) is a totally objective entity, like the classical electromagnetic field, and it follows that the collapse must be objective as well.
This is wrong. Or, more accurately, this description only works with a hidden variable theory, where we can interpret the wave-function as expressing ignorance of the hidden variables.


If one truly considers information fundamental, then one would focus on information and how it's used; one would focus on the fact that scientific predictions are done by gathering the results of 'measurement' and using them to predict the results of future measurements: i.e. it is about making statements like "X and Y, therefore Z" or "X and Y, therefore Z with probability p". Or more ambitiously, studying the dynamics of a theory to try and distill what sorts of things could be observed by an 'internal' observer that obeys said dynamics.

Even if our approach to considering statements is to have a prior physical model (e.g. wave-function) of a system, make observations (X and Y), and then make a prediction, collapse is not required to derive "X and Y, therefore Z with probability p". Even if we believe the wave-function to be an objective property of the system, this still does not imply collapse.

Really, the wave-function of a system is like expressing a classical system by the coordinates of its components. There is redundancy in such a classical description of a system because a change of coordinates would describe the same system. This does not force us to believe the classical description is just subjective information -- it just means we have to pay attention to which aspects of the description are physically meaningful and which are not.

The same is true with the wave-function (supposing that a decoherence-based interpretation of QM does work out); if we're considering the topic "What can we conclude from X and Y?", then collapse is simply analogous to the change of coordinates; a different presentation of the same quantum system from which we derive the same physical information. The collapse is not invoked as an update of information or even as an objective physical process but instead simply a mathematical simplification.



Collapse as update of information only comes if one cannot bear to think in terms of questions like "Do X and Y imply Z?" and instead insist merely on asking "Z?", and are thus forced to reformulate everything to implicitly include the hypotheses X and Y.

Similarly, objective collapse only comes into play of one cannot bear to think the meaningful physical questions are of the form "Do X and Y imply Z?" rather than "Z?", and are thus forced to suppose the objective state of the system evolves to implicitly include the hypotheses X and Y.

And both of these approaches suffer from the fact they explicitly reject the unitary time evolution asserted by the Schrödinger equation and similar (with superficially different justifications). Among other things, this rejects the possibility of quantum mechanics being able to describe physical experiments* and observers. I consider this to be a rather serious failing of such approaches, since you are paying a rather severe price for something that doesn't matter.

*: as opposed to being restricted to describing just the quantum system being observed in the experiment
 
  • #217
Hurkyl said:
Collapse as update of information only comes if one cannot bear to think in terms of questions like "Do X and Y imply Z?" and instead insist merely on asking "Z?", and are thus forced to reformulate everything to implicitly include the hypotheses X and Y.
That is true. But one can equally say that the issue of what implies Z only comes up if one "cannot bear" to simply say "what happened? Oh, Z happened". The need to connect Z, which is already a type of information, with what "implied" it, is a fundamentally rationalistic view of information. The empirical view of information is that the outcome of the experiment is the information of the theory, so there is no automatic reason to think the "X and Y implies Z" (where Z is probability distribution rather than a single perceived outcome) is the default form of information, and is probably not the type Rap has in mind.
 
  • #218
What about this argument against the subjective information (epistemic) view:
Its underlying idea is that any account which denies quantum probabilities the status of objective features of the world inevitably must make it mysterious how the theory helps us achieve even the modest goal of “the pragmatic business of coping with the world”—let alone the more ambitious goal of “finding out how the world is.”
And with respect to updating of information:
If there is no objective answer as to how some assignment of probabilities should be updated in the light of new evidence, it becomes a miracle that updating probabilities as we do is of use.
In defence of non-ontic accounts of quantum states
http://arxiv.org/pdf/1204.6738v1.pdf
 
  • #219
bohm2 said:
What about this argument against the subjective information (epistemic) view:

And with respect to updating of information:

In defence of non-ontic accounts of quantum states
http://arxiv.org/pdf/1204.6738v1.pdf

i think that the problem of epistemic non ontic is like describe something in a superficial manner, unlike of epistemic ontic or ontic.
i mean, talk about somebody just seeing some visual attributes (can be known ?)
 
  • #220
bohm2 said:
What about this argument against the subjective information (epistemic) view:
I don't find the objection convincing. If I'm playing poker, I'm clearly using informational techniques to assess probabilities, but the ontic nature of the situation is that the other person has just one single hand. What are the "objective features" I'm using in my probabilities? Is it a "miracle" if I can assess useful probabilities using various sources of information, even though my information has no direct connection to that single hand they possess? I just don't see any reason that primarily epistemic thinking should have any difficulty achieving good results, even in a purely classical setting. Or weather prediction...
 
  • #221
Ken G said:
If I'm playing poker, I'm clearly using informational techniques to assess probabilities, but the ontic nature of the situation is that the other person has just one single hand. What are the "objective features" I'm using in my probabilities? Is it a "miracle" if I can assess useful probabilities using various sources of information, even though my information has no direct connection to that single hand they possess? I just don't see any reason that primarily epistemic thinking should have any difficulty achieving good results, even in a purely classical setting. Or weather prediction...

But if one is playing poker or blackjack, one can update probabilities as one sees new cards dealt to other players and vary bet accordingly to maximize gains. Consider this statement by the author of the paper I linked:
If there is no objective answer as to how some assignment of probabilities should be updated in the light of new evidence, it becomes a miracle that updating probabilities as we do is of use. Thus we see that the main force of the means/ends objection to quantum Bayesianism, as we see, derives from that position’s denial of the assumption that we can ever know what observable some measured value is a value of.

Timpson outlines a possible quantum Bayesian reply to this challenge “of broadly Darwinian stripe”. According to this reply, “[w]e just do look at data and we just do update our probabilities in light of it; and it is just a brute fact that those who do so do better in the world; and those who do not, do not.” This response, however, as he argues, is ultimately unsatisfying in that it does not address the original worry, namely, “why do those who observe and update do better[.]” Given that according to quantum Bayesianism no way of updating in the light of incoming data counts as correct (in contrast to all others), this challenge is really serious.
Maybe I'm misunderstanding but I would think that the card example would be an argument against many of the purely subjective/non-ontic interpretations?
 
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  • #222
Ken G said:
I don't find the objection convincing. If I'm playing poker, I'm clearly using informational techniques to assess probabilities, but the ontic nature of the situation is that the other person has just one single hand. What are the "objective features" I'm using in my probabilities? Is it a "miracle" if I can assess useful probabilities using various sources of information, even though my information has no direct connection to that single hand they possess? I just don't see any reason that primarily epistemic thinking should have any difficulty achieving good results, even in a purely classical setting. Or weather prediction...

I think the point is that in classical (Bayesian) probability, there is an interplay between the ontic and the epistemic. You assume that there is some unknown actual arrangement of cards, and your probabilities are updated to reflect your knowledge about this arrangement. It's hard to understand how you can have epistemic probability without a corresponding notion of what is really the case.
 
  • #223
The point I have made concerning the information interpretation and the "projection postulate" is one which is strict to the case of quantum interpretation. I am talking strictly about the issue of correspondence between description and system, unlike other interpretations of quantum mechanics which do not address this issue in favour of interpreting the description, the mathematics. They only do so with the assumption that the mathematics somehow is assumed to be the real picture.
In the information interpretation we consider the mathematics to be important in that it reproduces the results of the experiments of quantum mechanics, but does the math really correspond directly to reality as the EPR paper would assume? In the info interpretation the correspondence is provided between system and description by simply stating that the system IS the information which the description provides (which can be formulated into elementary propositions) rather than looking for the description (which is very very abstract, probabilistic, etc.) to be describing the system directly. In this interpretation, correspondence is via information theory and information theory ALONE.
So when we say that the system is an amount of information, don't expect for that information to be anything more than the description : propositions like; the position is X, the momentum is Y. Not propositions about the laws of quantum mechanics, that is information too, but not the specific information that the system IS. So forget about probabilities, and poker, and information like " if X and Y then Z". These are not the info that the info interpretation sais that the system is.
 
  • #224
al onestone said:
The point I have made concerning the information interpretation and the "projection postulate" is one which is strict to the case of quantum interpretation.

Sorry to randomly but in: just to interject that I don't think the so-called 'projection postulate' is actually a part of the formalism of QM. Rather, it is better understood as an ad hoc rule by which (in the absence of a more principled treatment [as a card-carrying Everettian, you know where I'd think one might be obtained]) we extract empirical content from the formalism. Further, it isn't even any more a particularly good reflection of practice in physics: any serious treatment of the quantum physics of measurement uses something much more sophisticated.
 
  • #225
rodsika said:
But there is still a possibility that the observer and projection postulate in Copenhagen can be literal, isn't it? (Copenhagen just assumes it's calculation aid... but there is possibility it is real). Or has this idea been totally refuted already? How?

Modern treatments of quantum measurement use much more sophisticated tools.

For an introduction to this area see wiki's: http://en.wikipedia.org/wiki/POVM
 
  • #226
Rap said:
As one who favors the CI, this reminds me of the theory of planetary orbits. Medieval scholars believed the planets were pushed around by angels. Then Newton came up with orbital mechanics - a calculational tool to calculate the orbits of the planets without recourse to angels. The theory was "deprived" of its angels. Trying to recover "reality" from the CI is like trying to recover the angels, wondering what goes on in their minds that causes them to push the planets around according to an inverse square law. I mean, sure, maybe angels really are pushing the planets around according to the equations of orbital mechanics, but most physicists don't bother with the idea, since it is not a concept that can be decided by any repeatable measurement. Its not scientific. In particular, the "many worlds" interpretation is especially aggravating to one who favors the CI. It is a completely untestable theory that makes the most simplistic attempt to recover the angels, because, well, there just HAS to be angels, doesn't there?

Consider the following theory of fossils - we are not entitled to view fossils as evidence for dinosaurs, but rather we have available a certain well-known formalism that we can use to model found-fossils and also make predictions about fossils yet to be discovered. Of course, even creationists would find this theory a little strange. If our theory calls for certain complexes of book-keeping devices that act upon certain other such complexes, we can cut down on inelegant talk by considering naming such complexes as e.g. 'dinosaurs' and, noting such 'dinosaurs' appear to act on, and also be acted upon by, other 'dinosaurs'. (Evidence for which is extracted from examining fossil records) Our theory might in turn be underpinned by a principle that runs something like 'if one real thing (dinosaur a) is acted upon by another thing (dinosaur b) then the latter is also real'. This new theory - of real dinosaurs - seems much more elegant then the complicated instrumentalist approach to a theory of fossils. Incidentally, it also much more in keeping with how we ordinarily view all the other sections of science.
 
  • #227
rodsika said:
 

[1] "On the other hand, an unobserved quantum entity possesses "more
reality" than that available to ordinary objects because it can entertain in
potentia a multitude of contradictory attributes which would be impossible for
any fully actualized entity."

[2]Many Worlds has a severe problem in the "measure" mentioned by Everett. For
example, if we make a photon hit an angled sheet of glass, we can make the
probability of reflection anything we like just by adjusting the angle, say,
1/5. But in many worlds, splitting is equal. So how is it distributed. This is
the severe "measure" problem in Many Worlds that is even harder than the
collapse postulate. One can treat the collapse postulate arbitrariness just like
the constants of nature values being arbitrary. They are simply part of the
world. Here Many Worlds is thus refuted.

[1] This doesn't appear to mean anything! Anything MWI has to offer is less crazy and more in keeping with the history of science than the idea that the Potential affects the Actual. On the other hand, every interpretation of QM that doesn't require us to modify the formalism or take an anti-realist stance on the scientific enterprise must incorporate those features interpreted as 'worlds' in the MWI, but simply offer an argument at to why we regards these structures as 'Potentia' say, rather than 'real'. For example, one can introduce Bohmian particles to 'point at' the favoured structure, etc. (The most principled modificatory strategy is dynamical collapse, which makes other branches 'wither away')

[2] This is utter tripe, for a modern discussion see e.g. Wallace (20120
 
  • #228
Ken G said:
I'm saying that the goal of an interpretation is different from the goal of a theory.

On this philosophy-of-science point: can this distinction really be maintained? For example, modificatory interpretations of QM actually introduce novel formal devices, and so might be better seen as different theories (different, for example, to unitary quantum mechanics). Even no-collapse interpretations might be better construed as different theories - for example, though dBB recovers the quantitative / empirical predictions of the standard formalism, it too could be seen as a different 'theory' - albeit in this case the hidden variables are idle wheels in both formal and empirical senses, perhaps the difference lies in explanatory motivations... Regardless of the resolution of the latter issue, I dislike the term 'interpretation'. In my example of a theory of dinosaurs above, it would seem strange to talk about an 'interpretation of the fossil record'.
 
  • #229
stevendaryl said:
I think the point is that in classical (Bayesian) probability, there is an interplay between the ontic and the epistemic. You assume that there is some unknown actual arrangement of cards, and your probabilities are updated to reflect your knowledge about this arrangement. It's hard to understand how you can have epistemic probability without a corresponding notion of what is really the case.
Fuchs
...The quantum system represents something real and independent of us; the quantum state represents a collection of subjective degrees of belief about something to do with that system (even if only in connection with our experimental kicks to it). The structure called quantum mechanics is about the interplay of these two things|the subjective and the objective...
.
 
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  • #230
bohm2 said:
But if one is playing poker or blackjack, one can update probabilities as one sees new cards dealt to other players and vary bet accordingly to maximize gains. Consider this statement by the author of the paper I linked:

Maybe I'm misunderstanding but I would think that the card example would be an argument against many of the purely subjective/non-ontic interpretations?
My point with the cards is that it is not just objective evidence we are using (based on a random deal of given cards, some of which we've seen), but our impressions of the actions of our opponents. Two different players might assess the probability of a hand very differently as a result, and as they are counting different things as important, they will not even categorize hands into the same sets (for checking their probability determinations) as someone else. So both could conclude their probabilities are working for them, and are checked by many trials, even though the probabilities are different. As such, there is no such thing as the "correct probability" that a given hand will win, so there is no such ontic entity as the "actual probability". Even so, there are good poker players, and bad poker players, based on their probability assessments. That quote seems to claim we should view this fact as a "miracle."
 
  • #231
malreux said:
On this philosophy-of-science point: can this distinction really be maintained?
I think so. It's true that "lines in the sand" are always hard to draw, because the situation requires more flexibility. But there is a pretty clear need to distinguish the predictions a theory makes, which are testable, from how we interpret the workings of the theory, which is not testable. Even Newtonian mechanics admits to multiple interpretations (are there really forces, which then allow us the mathematical invention of action? Or is there really action, which allows us the mathematical invention of forces? Does neither exist, and they are both just ways we can picture our theory, like imagining an image charge to help us solve for a field?)
For example, modificatory interpretations of QM actually introduce novel formal devices, and so might be better seen as different theories (different, for example, to unitary quantum mechanics).
The devices don't make them a new theory, it is their predictions. If they don't make new predictions, they can't be a new theory. Here is where the sands get shifting, because some interpretive devices do sort of make predictions, but they don't guide any new observations, because the predictions are impossible to observe, realistically (like the Hawking radiation of a stellar-mass black hole, or some such thing).
Regardless of the resolution of the latter issue, I dislike the term 'interpretation'. In my example of a theory of dinosaurs above, it would seem strange to talk about an 'interpretation of the fossil record'.
That's because it's not an interpretation, it's a theory. We theorize various dinosaurs, and we make predictions about those dinosaurs. Those predictions are very different from some other theory. The predictions apply to fossils we have not yet found, or were made before the fossils we have now found.
 
  • #232
Ken G said:
[1] [T}here is a pretty clear need to distinguish the predictions a theory makes, which are testable, from how we interpret the workings of the theory, which is not testable.

[2] If they don't make new predictions, they can't be a new theory.

[3] That's because it's not an interpretation, it's a theory. We theorize various dinosaurs, and we make predictions about those dinosaurs. Those predictions are very different from some other theory. The predictions apply to fossils we have not yet found, or were made before the fossils we have now found.

[1] Your definitely on to something there. However, recalling Einstein's dictum that 'observables' are defined by a theory,* and glancing at the defunct position of say, positivism, one can safely draw the inference that the observable / non-observable distinction is, at best, irrelevant to a functionalist understanding of our best physical theories. On the other hand, the main 'interpretation' of scientific theories in most fields is surely some form of structural realism?

[2] By your lights Darwin's theory of natural selection was not much better than Lamarck's, at least by the standards of his day.

[3] Here you make the nice distinction do a lot of work: e.g. you seem to use the term 'theorize' to mean 'add to our theoretical ontology' whereas most people - scientist or non-scientist - would prefer the term 'discover'. Further, theories can differ whilst predicting the same phenomena - the so-called theoretical underdetermination by data. If you think theories are essentially about prediction, or that this is what makes them scientific, consider replacing a certain theory with a long sentence that omits all theoretical terms so far as it can recover them with observation statements. In practice, you will find you can rarely actually carry this through. This is a very weak argument, essentially arguing that 'if you can't simulate it, you don't know it' - but it sounds plausible enough to me...

*To slightly paraphrase
 
  • #233
Ken G said:
The devices don't make them a new theory, it is their predictions. If they don't make new predictions, they can't be a new theory.

I should add that some recent collapse theories do actually make potentially testable predictions, i.e. e.g. if collapse time ≥ decoherence time
 
  • #234
superposition time vs the time of decoherence.
if last less (sp), nonlinear models are the correct.
 
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  • #235
malreux said:
On the other hand, the main 'interpretation' of scientific theories in most fields is surely some form of structural realism?
There is indeed difficulty in separating a "pure" observation from a "pure" theory, as we need some kind of model of what we are doing to even read a dial. But I think it is still not so hard, as distinctions go, to distinguish between "a spot appeared on a screen, so I'm detecting an event happening at that point in space and time" and "a particle passed through one/both/neither slit along the way." The former very definitely seems like an observation, the latter, an interpretation. The structural realism certainly applies to our devices-- we all imagine the screen is real, the spot is real. But the extrapolation from what we participate in, and develop as part of what physics is, to everything that happens along the way, was always a bit of a leap of faith for structural realism. Indeed, I've argued that somehow, what seems "realistic" vs. "antirealistic", has gotten inverted-- it seems realistic to me to expect that the universe does not have to behave, when unobserved, the same as it does when it is observed (since observation is a form of making the universe fit into a particular way of interacting with it and conceptualizing it in our limited human brains), and antirealistic to be carried away on a leap of faith.
[2] By your lights Darwin's theory of natural selection was not much better than Lamarck's, at least by the standards of his day.
I don't think so. Darwin's approach makes lots of predictions, like if you change the surroundings of a moth to a differently colored environment, you will expect to watch the moth color gradually change over by natural selection. There is no equivalent at all in Lamarck's theory to that kind of change, simply because moths are not observed to change color in their own lifetime.
[3] Here you make the nice distinction do a lot of work: e.g. you seem to use the term 'theorize' to mean 'add to our theoretical ontology' whereas most people - scientist or non-scientist - would prefer the term 'discover'.
The terms ovelap-- we discovered a theory about dinosaurs. It is considered a very good theory, after some initial modifications, because it became able to predict new fossil discoveries that were indeed later found. There is an important distinction, owed to Popper, between just using a theory to "make sense of" what you observe (which is easily used to fool ourselves, a form of "rationalization" of our findings-- just look at how creationists do it), versus actually making "risky predictions" (predictions that we would have no reason to expect if we had no understanding of that theory). It is the latter that makes us trust a theory, though the former is how we use the theory on a day-to-day basis.
Further, theories can differ whilst predicting the same phenomena - the so-called theoretical underdetermination by data.
But they cannot predict all the same phenomena, or they do not differ. We don't regard Hamiltonian mechanics as a different theory from Newtonian, though they bear little resemblance at first glance, because they make all the same predictions.
If you think theories are essentially about prediction, or that this is what makes them scientific, consider replacing a certain theory with a long sentence that omits all theoretical terms so far as it can recover them with observation statements.
That fails the most important test of all: Occam's Razor. The job of a theory is to predict, the job of a good theory is to unify those predictions into as simple a framework as possible, and the job of an interpretation of a theory is to "make sense" of what the theory is asserting about reality. But the latter two are not unique, and the last one is downright problematic (but we do it anyway, because no one really holds to "shut up and calculate", no one is really satisfied by that).
This is a very weak argument, essentially arguing that 'if you can't simulate it, you don't know it' - but it sounds plausible enough to me...
I believe I understand what you mean, you are saying that the simple theory is more than just a way to get the predictions in a unified way, it is actually the goal itself. It begins to sound rationalistic, like the first step in saying that nature really does follow mathematical rules, and we are just incompletely converging on them. That argument never really washed for me though, it sounds like we are simply taking our converging accuracy and mistaking it for converging on truth. I just don't see any credible argument that leads to that conclusion, it seems like wishful thinking.
 
  • #236
malreux said:
I should add that some recent collapse theories do actually make potentially testable predictions, i.e. e.g. if collapse time ≥ decoherence time
Yes, I'm not categorically claiming that's impossible, I just haven't really seen anything all that convincing that such different predictions are really plausible. But we can agree that if such predictions are possible to test, then we will no longer have to call them interpretations, we can justify the claim that they have become new theories. It's not unusual for an idea that starts out a kind of interpretation, or even just a philosophical kernel, to get expounded to the point that it does qualify as a scientific theory.
 
  • #237
Ken G said:
[1] The structural realism certainly applies to our devices-- we all imagine the screen is real, the spot is real. But the extrapolation [...] to everything that happens along the way, was always a bit of a leap of faith for structural realism.

[2] Indeed, I've argued that somehow, what seems "realistic" vs. "antirealistic", has gotten inverted-- it seems realistic to me to expect that the universe does not have to behave, when unobserved, the same as it does when it is observed.

[3] Darwin's approach makes lots of predictions, like if you change the surroundings of a moth to a differently colored environment, you will expect to watch the moth color gradually change over by natural selection. There is no equivalent at all in Lamarck's theory to that kind of change, simply because moths are not observed to change color in their own lifetime.

[4] There is an important distinction, owed to Popper, between just using a theory to "make sense of" what you observe [..] versus actually making "risky predictions"

[5] But they cannot predict all the same phenomena, or they do not differ.

[6] We don't regard Hamiltonian mechanics as a different theory from Newtonian, though they bear little resemblance at first glance, because they make all the same predictions.

Thank you for your thorough reply. I feel (hopefully falsely!) that this line of debate doesn't particularly interest you, however.

I won't bore you with scholastic debates regarding the distinction between observation and interpretation. I'll simply reiterate my view that an answer to the question 'what is an observable?' is theory-dependent.

[1] I leapt in with my earlier post without even suggesting what I meant by 'structural realism'. All I mean by this is answered here: http://plato.stanford.edu/entries/structural-realism/

[2] Of course. However I hope I'm not just getting carried away and inferring reality willy-nilly. The way I put it above was - if we have Real Pattern A and find it interacts with Pattern B, then we can award the latter the nice distinction 'real'.

[3] Quite so: Darwin's theory has more predictions to make. However, why was Darwin always amassing evidence for evolution? Not to generate novel predictions, that's for sure. Incidentally, remember Popper at times actually comes off as a bit of an evolutionary sceptic - although one doesn't need to retain this aspect of Popper's thinking to be a good falsificationist, a la Deutsch.

I don't think anyone has ever thought the reason theorizing that fossils were records of animals once extant is attractive is solely or mainly because it might make good predictions about future fossil finds. Or at least, that's a very strange way of putting it.

[4] This is just a matter of emphasis. Explanations that are hard to vary also characterise much of science and what is scientifically good about it.

[5] Untrue, consider some pregnant comments by Wittgenstein on the subject of observation and the helio-versus-geocentric controversy

[6] There is a relevant equivalence between Hamiltonian mechanics and Newtonian physics due to predicting the same quantities, but this is hardly the only or even the most physically interesting equivalence. Also, the former is a representation of (aspects of) the latter.*

Finally, I'd like to assure you that I don't exactly care whether our theories are converging on the truth ('approximating' is the fashionable jargon), I just think that if you look at e.g. fundamental physical research, as practised, and you can actually do quite a bit of work in epistemology, metaphysics and the like. The motivation for doing so is also related to whether you find the following question interesting: 'what must the world be like for our current best theories to be ('aprox') true?'

*In this case, i.e. not generalising to 'Hamilton's principle'
 
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  • #238
Hi, I voted "Other", but what I mean by this is rather "I don't know". I lean towards the Ensemble interpretation or Copenhagen. I also think the Relational interpretation is interesting.
 
  • #239
Although one can debate the categories you offer as options, I think this poll is a great thing and should def become an official annual event for phys forum. People offer similar things at foundational conferences.

However, like everybody else, I imagine my own 'interpretation' of QM doesn't quite square with any of the options - I'd even prefer a vaguer description as an option, like 'quantum theory is a theory of local interactions and nonlocal states' to sum up my stance. Regardless, good work on starting this thread! It's cool to have a handle on what people are thinking.
 
  • #240
I've always wondered what the difference is between Many Worlds ( With splitting of worlds ) and Everettian MWI (Decoherence). What is the difference between splitting and decoherence such that 13 people would flock to the former and 17 to the latter?
 
  • #241
lmoh said:
I've always wondered what the difference is between Many Worlds ( With splitting of worlds ) and Everettian MWI (Decoherence). What is the difference between splitting and decoherence such that 13 people would flock to the former and 17 to the latter?

Good question! I settled for the latter, but the distinction is vague, as stated. Does it mean that e.g. Lev Vaidman would plump for the former and e.g. Hilary Greaves would plump for the latter?

Personally, I think the only important distinction between MWI proponents is between those who thought 'worlds' had to be added to the formalism (to derive 'many exact worlds') and those who appeal to decoherence and the Church of the Larger Hilbert Space. [Note tenses]
 
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  • #242
malreux said:
I'll simply reiterate my view that an answer to the question 'what is an observable?' is theory-dependent.
An example might help-- in what theory is a spot on a screen not an observable?
[1] I leapt in with my earlier post without even suggesting what I meant by 'structural realism'. All I mean by this is answered here: http://plato.stanford.edu/entries/structural-realism/
Yes, I take your meaning-- naive realism is not tenable, but structural realism is a kind of compromise. The best of both worlds, or all the problems of each without any solutions? Murky waters, to be sure, it contents me to say that we impose our way of interacting with nature when we try to describe nature, so we are involved in deciding what we shall regard as real.
[2] Of course. However I hope I'm not just getting carried away and inferring reality willy-nilly. The way I put it above was - if we have Real Pattern A and find it interacts with Pattern B, then we can award the latter the nice distinction 'real'.
I still don't think it's that hard to distinguish the claim "large reptiles roamed the Earth and left footprints and fossils", which is a theory (it unifies a bunch of observations and makes testable predictions) from the claim "the electron definitely goes through one slit, decided by hidden aspects of its preparation, but the hidden aspects evolve dynamically as an unobservable pilot wave that goes through both slits", which is an interpretation of the Schroedinger equation (and adds nothing to the observations that we can use the Schroedinger equation to predict). I think the problem is, you are talking about how we interpret observations, but how we interpret observations is what a theory is because it involves being able to predict those observations. I am talking about how we interpret our theories, not our observations, so it does all begin with a distinction between what we observe and how we understand and predict what we observe. Your point that such a distinction can be problematic is well taken, but that doesn't mean it is invalid to see value in the distinction, the distinction is just not as clear as we might like.
[3] Quite so: Darwin's theory has more predictions to make. However, why was Darwin always amassing evidence for evolution? Not to generate novel predictions, that's for sure.
Presumably he was checking the novel predictions, the other half of good science.
I don't think anyone has ever thought the reason theorizing that fossils were records of animals once extant is attractive is solely or mainly because it might make good predictions about future fossil finds. Or at least, that's a very strange way of putting it.
I doubt anyone holds that this is the "sole" or "main" duty of a scientific theory, only that it is a required duty.
[4] This is just a matter of emphasis. Explanations that are hard to vary also characterise much of science and what is scientifically good about it.
Yes, but that is not all they do, to be a theory. All good scientific theories have made predictions about things that hadn't been observed yet. If all a theory does is tie together existing data, no matter how tidily, it is not a scientific theory, it is just a nice piece of rationalization. It certainly hasn't happened yet that a good theory has been like that, but we are just starting to see some theories like that now (string theory, chaotic inflation, etc.), and there are serious questions around whether these are science or rationalization.
[5] Untrue, consider some pregnant comments by Wittgenstein on the subject of observation and the helio-versus-geocentric controversy.
Well I'm not sure exactly what Wittgenstein said, though I'd be interested in hearing it But I'm not sure I'm going to think he was right, because the geocentric vs. heliocentric controversy was a classic example of two different theories being decided by the different predictions they made (most notably around telescopic observations of the phases of Venus, and elliptical orbits). Prior to the observations (by Galileo and Tycho), no person on Earth had any idea which was going to be the better theory, they could only guess.
[6] There is a relevant equivalence between Hamiltonian mechanics and Newtonian physics due to predicting the same quantities, but this is hardly the only or even the most physically interesting equivalence. Also, the former is a representation of (aspects of) the latter.*
Well, I'm not sure what is the most interesting aspect of the equivalence, my point is only that they are equivalent, yet invoke such completely different ontologies that it becomes clear we are not answering "what must the world be like for this theory to work well."
 
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  • #243
Ken G said:
[1] An example might help-- in what theory is a spot on a screen not an observable?

[2] [It] contents me to say that we impose our way of interacting with nature when we try to describe nature, so we are involved in deciding what we shall regard as real.

[3] [...] the hidden aspects evolve dynamically as an unobservable pilot wave that goes through both slits", which is an interpretation of the Schroedinger equation (and adds nothing to the observations that we can use the Schroedinger equation to predict).

[4] I am talking about how we interpret our theories, not our observations, so it does all begin with a distinction between what we observe and how we understand and predict what we observe. Your point that such a distinction can be problematic is well taken, but that doesn't mean it is invalid to see value in the distinction, the distinction is just not as clear as we might like.

[5] Yes, but that is not all they do, to be a theory. All good scientific theories have made predictions about things that hadn't been observed yet.

[6] If all a theory does is tie together existing data, no matter how tidily, it is not a scientific theory, it is just a nice piece of rationalization. It certainly hasn't happened yet that a good theory has been like that, but we are just starting to see some theories like that now (string theory, chaotic inflation, etc.), and there are serious questions around whether these are science or rationalization.

[7] Well I'm not sure exactly what Wittgenstein said, though I'd be interested in hearing it

[8] Prior to the observations (by Galileo and Tycho), no person on Earth had any idea which was going to be the better theory, they could only guess.

[9] My point is that [Hamiltonian mechanics and Newtonian physics] are equivalent, yet invoke such completely different ontologies that it becomes clear we are not answering "what must the world be like for this theory to work well."

[1] There's a type of structural realism - to which I do not subscribe - called epistemic structural realism. Some proponents of which take it that even looking at blood cells under a microscope is somehow 'theory-laden'. Whatever you think of that view (I think its crazy), you correctly infer my real meaning in [2].

[2] Yup. Laws describe / explain /predict some classes of observations, not others. Fields make sense with cut-off's, not otherwise (despite the project of algebraic-approach axiomatic field theories best attempts, etc.)

[3] Well, this is a bad interpretation, so far is goes, because in this case the hidden variables are 'idle wheels'.

[4] I'm gesturing, with only a little argument, to the status of observable/non-observable. For the logical empiricists of the early twentieth century, this distinction was paramount, despite the fact the QM revolution had already showed this distinction to be, as you put it, 'problematic'. However, I previously began with the crackpot* tactic of comparing my view to Einstein's - I stand by my paraphrase - observables are defined within some theory. This needn't drive one to the extremes of ESR, nor make one particularly interested in contextual epistemology and so on. As distasteful as I ultimately find their antirealism, it's worth checking out http://plato.stanford.edu/entries/constructive-empiricism/ if your interested in how this distinction plays out for modern empiricists.

[5] I'm not sure if this is entirely historical accurate; regardless, the crucial point your making is that at various junctures in the history of science, a 'crucial experiment' has often been the ultimate arbiter between competing theories.

[6] Unfortunately, your going to be very disappointed about the future of physical research. One thing that's happening here I think is we're gradually coming out of one paradigm and entering another, in terms of e.g. experience and fundamental physical research. A lot of things that the early originators of QM thought were impossible to talk about, or were inherently arbitrary, are now routinely examined in the lab, or by the theorist. I'm thinking here of the quiet revolution re POVM's, and also the viability of the modern medium decoherence programme. On the other hand, we're rapidly approaching regimes where no viable experimentation will be likely to occur - the most obvious case: quantum gravity. Further, some of the 'problems' of interpretation just aren't physical problems - e.g. if we have a viable interpretation of the formalism of QM that is capable of being rendered relativistically covariant - I'm thinking here of MWI - and also provides a 'realist' interpretation of the theory, i.e. like all previous scientific theories, then it really seems to me that the outstanding questions about such an 'interpretation' are purely philosophical. They arise because some intuitions - e.g. 'experiments have unique outcomes' - are difficult to work around or without. Hence a place where a philosopher might actually have something useful to say. (Or not ;-))

[7] My interpretation of what he meant is: one class of observations that were useless to Galilei's contemporaries are observations of the sun itself - since it might look the same whichever theory is correct. Point being that the theory predicts other observations to test. An example from Deustch might clarify: why was the ancient Greek theory about the seasons a bad explanation? They thought (roughly) that the cooler seasons arose from Persephone being snatched by the lord of the underworld, and the warmer season from Persephone being returned to her divine mother, in a cyclical process. However, if they had traveled further south, they would have noticed a class of observations difficult to reconcile with this view. I.e. opposite seasons. The complications to the narrative would have been mighty, of course, but the myth has no resources to accept these new observations. The theory whereby the Earth spins on an axis tilted with respect to its own planar rotation can not only accommodate these observations, it predicts them. Notice how the predictions re observations arise from the theory - the theory is realist, but it doesn't matter (scientifically) that the theory is realist in the sense of entity realism i.e. asserting the reality of entities 'Earth' and so forth. Indeed, since SR suggest a rigid body cannot be defined (is not physically possible), fundamentally, the Earth cannot be a rigid ball with titled axis. At a certain level of description, however, this is a perfectly fine thing to work with.

[8] Yes, exactly right.

[9] Please note I didn't want to talk about "what must the world be like for this theory to work well" but "what must the world be like if our (best) theories are approximately true. Regardless, look there's a lot I could say here but we've been dragging this conversation on further and further away from the subject of this thread. If the mods don't mind, then let's carry on, otherwise we should start a new thread.

Your [9] needs to clarify some things - what exactly is the 'ontology' of the Hamiltonian, for example? This is not as easy a question as it (may!) seem. Sometimes we're discussing the status of things like ordinary tables and chairs with regards to fundamental physical ontology (emergence?), other times we're discussing the ontology of particular physical theories (is the wavefunction real?). We could focus this discussion a lot more on a new thread if you think its worth it.

A note on structural realism as the worst of both worlds: I tend to think of it (unsurprisingly!) as the best of both of worlds, conversely. This works by combining two arguments - the (1) 'no miracles argument' and (2) the 'pessimistic meta-induction' (sounds grandiose, right?). (1) states that it would basically be a miracle if our scientific theories weren't even remotely true, because we predict phenomena, safely use technology (sometimes!), etc. So, to some extent, our best theories approximate the truth (a fortiori). (2) is usually presented as an induction, though it also has a deductive variant (that isn't sound, so ignore it): scientists had good reason to believe past scientific theories (evidence, predictions), those theories have all turned out to be false, scientists have good reason to believe current theories, they will overwhelmingly likely turn out to be false, so we shouldn't believe our best theories. Whatever you think about this argument, it is clearly aimed at that I called 'entity realism' above - where you claim a class of entities predicted by some theory really exist. E.g. if, for example, an old theory of combustion predicted a substance called phlogiston, and a new theory jettisoned it from our ontology, replacing it with, say, oxygen, or rejecting what it doesn't 'replace' by stating there is no further use for such things, then the old entities are 'falsified' (in this sense). However, look at the continuities between the two theories of combustion - though one class of entities is out and a new class in, the actual structure of the mathematical description is not so sharply different. Consider the revolution of special and general relativity - they both contain Newtonian physics as a limit case. What is revolutionary and what is continuous are both structural features, mathematical cores. So perhaps these are the bits of our theories that, to some extent, latch onto nature. Or so I contend.
*In Baez's sense
 
  • #244
malreux said:
[[3] Well, this is a bad interpretation, so far is goes, because in this case the hidden variables are 'idle wheels'.
That has always been my objection as well, but I would stop short of calling it "bad", because it is very hard to use absolute terms when dealing with interpretations. Some very bright people, including de Broglie himself, thought it as a good interpretation, and for many of the same reasons that we think it is bad. So it is clear we don't agree on the requirements for a good interpretation-- that's an important thing to recognize about interpretations, perhaps even the most important thing. Even though I prefer some to others, and can give reasons why, I recognize them all as valid in their own way, and I'm glad to know them-- there's not one I wish I hadn't met!
[4]As distasteful as I ultimately find their antirealism, it's worth checking out http://plato.stanford.edu/entries/constructive-empiricism/ if your interested in how this distinction plays out for modern empiricists.
I haven't penetrated to the controversy yet, because at first glance, constructive empiricism appears to make the claim from this quote:

"Science aims to give us theories which are empirically adequate; and acceptance of a theory involves as belief only that it is empirically adequate."

Naive realism, on the other hand, appears to make the claim from this quote:

"Science aims to give us, in its theories, a literally true story of what the world is like; and acceptance of a scientific theory involves the belief that it is true."

Now, looking at those two statements, it seems to me that the first is scientifically demonstrable as basically correct (basic scientific history suffices), though it unnecessarily and inaccurately stresses the word "only" (the clear fact is that this is one of science's most closely held goals, but it is not the only goal of science, the other involving a sense of unification and understanding that goes quite a bit beyond empirical adequacy). But all that is obvious. The second quote, on the other hand, is clearly naive and rather absurd, and again even a rudimentary knowledge of scientific history suffices to demonstrate that. I can't even imagine how anyone holding that opinion is going to even begin to define the phrase "literally true" in a way that is remotely scientific, without ending up sounding like the first statement.
[5] I'm not sure if this is entirely historical accurate; regardless, the crucial point your making is that at various junctures in the history of science, a 'crucial experiment' has often been the ultimate arbiter between competing theories.
Yes, the role of "crucial experiments" cannot be understated, they are what volcanoes are to island chains and what wars are to nations. The main theories of physics do not tiptoe in the back door, they erupt with great pomp and circumstance, and always with some experimental result that no one had any reason to expect in the absence of the theory. Usually the result precedes the theory, but the successful theory also predicts additional things we would have no reason to expect without the theory, and that's how we verify the theory is not pure rationalization of something already known.
[6] I'm thinking here of the quiet revolution re POVM's, and also the viability of the modern medium decoherence programme.
Yes, POVM's are an interesting new direction to call attention to, and I can't see why I would have any "disappointment" associated with this. The intent of the program is, as usual in science, to be able to predict experiments, here those involving decoherence, such that the state of the system can be continuously tracked, not as an evolution from a pure state to a mixed state (which regular quantum mechanics does in concert with the Born rule or standard decoherence), but as evolution from a mixed state to a pure state. That's what is missing from quantum mechanics, and predictions along that path would be a new theory that would arrive with great fanfare and experimental confirmation.
On the other hand, we're rapidly approaching regimes where no viable experimentation will be likely to occur - the most obvious case: quantum gravity.
But do you think that is something new? The history of physics is peppered with periods where we were far from viable experimentation-- and it invariably led to a period of stagnation in physics.

As to the current state of affairs, we can certainly be optimistic if we are predisposed to be, but there is a danger that optimism gives way to self-deception and rationalization. The simple truth is, we have no reason to expect quantum gravity to provide us with a great new theory of physics that does not simply either repackage what we already know, or make predictions that we have no way of knowing would hold true if we could test them. Regardless of how aesthetically pleasing we might find notions of quantum gravity, that is just a sorry state of affairs, for science. The only hope is that there really will be some verifiable predictions that we could not anticipate without that quantum gravity theory.
Further, some of the 'problems' of interpretation just aren't physical problems -
Certainly. I would hold that no problems of interpretation are physical problems, they are all philosophical. They will only be physical problems when interpretations spawn new theories that actually make testable predictions.
An example from Deustch might clarify: why was the ancient Greek theory about the seasons a bad explanation?
But Deutsch is missing the deeper undercurrent here-- for even if seasons were the same in the southern hemisphere, the Greek model would still be of no value! That's because the model predicts nothing, it is a perfect example of a pure rationalization. It makes no difference if the rationalization works, there is no way to verify that it is saying something they didn't already know unless it makes a prediction they would not otherwise expect-- no matter what is happening in the southern hemisphere.
The theory whereby the Earth spins on an axis tilted with respect to its own planar rotation can not only accommodate these observations, it predicts them.
That's exactly my point, a theory must do more than rationalize what is already known, else there is no verification step. But this has nothing to do with realism or any other philosophical attachments, it is purely an issue of empirical evidence.
[9] Please note I didn't want to talk about "what must the world be like for this theory to work well" but "what must the world be like if our (best) theories are approximately true.
I don't see any distinction there, they both sound equally impossible to establish scientifically, and equally against the weight of scientific history. The world doesn't have to be "like" anything, it can just be what it is, and the theories can just work as well as they do, or do not. What more can be supported with evidence?
Your [9] needs to clarify some things - what exactly is the 'ontology' of the Hamiltonian, for example? This is not as easy a question as it (may!) seem.
I agree, but look how much more difficult that question becomes if we must bury the Hamiltonian under the weight of being something that "the world must be really like." That approach forces an ontology onto the Hamiltonian, it can no longer be what it demonstrably is-- a mathematical concept, pure and simple, with no need to say anything more. We are playing the game of math, and we are doing it in a way that mimics or apes the presence of some Platonic "Hamiltonian", but the tension between the game and the ontology need not make any contact with a "true game that math really is", or a "true Hamiltonian that the world is really like." Those concepts are completely superfluous-- all we need is the interplay between the syntax of the game and the semantics of the ontology, without taking either one seriously as a destination of its own.
Sometimes we're discussing the status of things like ordinary tables and chairs with regards to fundamental physical ontology (emergence?), other times we're discussing the ontology of particular physical theories (is the wavefunction real?). We could focus this discussion a lot more on a new thread if you think its worth it.
By all means, a thread exploring the purposes of the whole idea of having an ontology to prop up our thought processes would be quite interesting. It's relevant here as well though-- it's the reason that people like to imagine that math is Platonic, to have that prop.
A note on structural realism as the worst of both worlds: I tend to think of it (unsurprisingly!) as the best of both of worlds, conversely.
And I would agree that both views have their value-- the truth is in the tension between them, structural realism has value because it invokes a tension between being a vacant solution, and an effective solution, and that tension opens up a discussion about what kinds of solutions we are looking for and why. We expect this as soon as we see that solutions are contextual and provisional, so the job of philosophy is not just to find the solutions, but also to clarify their limits.
This works by combining two arguments - the (1) 'no miracles argument' and (2) the 'pessimistic meta-induction' (sounds grandiose, right?). (1) states that it would basically be a miracle if our scientific theories weren't even remotely true, because we predict phenomena, safely use technology (sometimes!), etc.
But this invokes a false dichotomy. Now we must choose between our theories being either "not remotely true", or being "like the world". What happened to the most likely case of all, neither one? Why can't the theories just work pretty darn well for what they are supposed to work for, and yet not be anything "like" the actual truth of the world (if it even makes sense to talk about a truth of the world, which I argue it doesn't-- truths are contextual and provisional too). My assertion requires zero assumptions not in evidence, the standard naive realism requires a leap of faith that is contradicted every time the ontologies of our theories take another inevitable radical shift.
(2) is usually presented as an induction, though it also has a deductive variant (that isn't sound, so ignore it): scientists had good reason to believe past scientific theories (evidence, predictions), those theories have all turned out to be false, scientists have good reason to believe current theories, they will overwhelmingly likely turn out to be false, so we shouldn't believe our best theories.
Actually, no induction whatever is required there. All that is required is the bedrock of science: basic skepticism. The requirement that a proposition be backed with evidence that is not constantly contradicted.
Consider the revolution of special and general relativity - they both contain Newtonian physics as a limit case.
That's a basic requirement of the simple fact that it is known that Newtonian mechanics works well for some things, and relativistic mechanics works well for others. Same for quantum and classical. It is not saying anything surprising that a theory that worked for something will continue to work for that same something, so it is a given that all superior theories will "contain" the inferior versions. Something that must be true is not evidence for something that does not have to be true. We can take it as given that our theories work well, there is no other claim that can be made on nature without leaving the realm of what we can support with evidence.
 
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  • #245
I believe I understand QM.

I rely on this august group of physicists to disabuse me of my illusion.

I begin by assuming the two most accurate and proven theories in physics are correct; QM and general relativity.

1. Relativity says that we exist in a 4 dimensional universe that we apprehend as a 3 dimensional universe. Einstein believed that this was an "illusion."

2. It is the force of electromagnetism that causes us to think the universe is 3 dimensional. This is the force that defines matter as we experience it in its various forms. It is also the force that defines time. The constant speed of C is what defines how much time elapses for us depending on our own speed through space and/or the gravitational force we are subjected to. It is also the force that provides time with its arrow. The sum of the speed through space and the speed through time must always equal C. As C is the limit of speed through space, it is impossible for speed through time to be negative without requiring speed through space to exceed C.

3. Essentially, we live in a 3 dimensional subset of the 4 dimensional universe that is "knocked down" by the reality of electromagnetism, which we are made of and live under.

4. The Schrödinger equation describes particles as waves that permeate all of space-time, i.e. existing in a 4 dimensional "block universe" that we find particularly difficult to conceptualize.

5. Decoherence occurs when these waves encounter electromagnetic forces that compel them to appear as particles in that particular 3 dimensional subset. Information theory has shown that additional dimensions add enormously to the amount of information that can be held by any bit. This is why waves in 4 dimensions appear to us in 3 dimensions as particles. The old "Flatland" metaphor illustrates this perfectly.

6. "Measurement" is simply one way of forcing these waves to decohere. Consciousness has nothing whatsoever to do with it. We rely on the force of electromagnetism for any measurement we make.

7. Once decohered, these waves appear to us as particles in our 3 dimensional subset universe. They continue to behave as waves in the 4 dimensional block universe.

8. The wave nature of matter is necessitated by the relativity of simultaneity. Each observer's reality is equally valid, even though it doesn't agree with other observers traveling through space at a different speed or subjected to different gravitational forces. This truth would simply be impossible if matter were particles. Waves allow matter to appear anywhere in the 4 dimensional block universe where it happens to get decohered through the force of electromagnetism.

9. This is also why quantum indeterminacy is a foregone conclusion once one accepts the relativity of simultinaity.

Bottom line, if you believe relativity is correct, quantum "weirdness" is a necessary result. Without wave-particle duality and quantum indeterminacy, relativity would have to be wrong. With it, it works like a charm.

Please help me understand why the above has been proven to be incorrect.

I'm searching for experimentally proven facts to blow this "understanding" out of the water!
 
<h2>1. What is the purpose of the Quantum Interpretation Poll (2011)?</h2><p>The Quantum Interpretation Poll (2011) was conducted to gather data on the opinions and beliefs of scientists and researchers regarding the different interpretations of quantum mechanics.</p><h2>2. How was the Quantum Interpretation Poll (2011) conducted?</h2><p>The poll was conducted through an online survey, where participants were asked to select their preferred interpretation of quantum mechanics and provide a brief explanation for their choice.</p><h2>3. What were the results of the Quantum Interpretation Poll (2011)?</h2><p>The results of the poll showed that the Copenhagen interpretation was the most popular among scientists, followed by the Many-Worlds interpretation and the Pilot-Wave interpretation.</p><h2>4. Were there any notable differences in opinions among scientists in the Quantum Interpretation Poll (2011)?</h2><p>Yes, there were notable differences in opinions among scientists, with some preferring more traditional interpretations such as Copenhagen, while others favored newer interpretations like Many-Worlds or Pilot-Wave.</p><h2>5. How has the Quantum Interpretation Poll (2011) impacted the scientific community?</h2><p>The poll has sparked discussions and debates among scientists about the different interpretations of quantum mechanics, leading to further research and exploration in this field. It has also provided insight into the current beliefs and opinions of scientists on this topic.</p>

1. What is the purpose of the Quantum Interpretation Poll (2011)?

The Quantum Interpretation Poll (2011) was conducted to gather data on the opinions and beliefs of scientists and researchers regarding the different interpretations of quantum mechanics.

2. How was the Quantum Interpretation Poll (2011) conducted?

The poll was conducted through an online survey, where participants were asked to select their preferred interpretation of quantum mechanics and provide a brief explanation for their choice.

3. What were the results of the Quantum Interpretation Poll (2011)?

The results of the poll showed that the Copenhagen interpretation was the most popular among scientists, followed by the Many-Worlds interpretation and the Pilot-Wave interpretation.

4. Were there any notable differences in opinions among scientists in the Quantum Interpretation Poll (2011)?

Yes, there were notable differences in opinions among scientists, with some preferring more traditional interpretations such as Copenhagen, while others favored newer interpretations like Many-Worlds or Pilot-Wave.

5. How has the Quantum Interpretation Poll (2011) impacted the scientific community?

The poll has sparked discussions and debates among scientists about the different interpretations of quantum mechanics, leading to further research and exploration in this field. It has also provided insight into the current beliefs and opinions of scientists on this topic.

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