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EPR/Bohm/Bell & Localism vs Universalism

  1. May 30, 2013 #1
    It is commonly understood that the progression from EPR to Bohmian mechanics to the Bell theorem relates to the idea that there is a common sense notion of the constitution of physical reality that is in need of being reevaluated. This notion is simply that the fundamental elements of physical reality are to be understood as causally isolated material points (ie particles). The name we can give to this notion is the principle of locality, or more simply, localism. It is further said that a thorough understanding of Bell -- especially in light of the experimental confirmations starting with Aspect -- leaves us with nothing other than a physical reality that is essentially "non-local".

    This is where I start to have issues. That is, even though we know what physical reality is *not*, we are no further along the line concerning what it *is*. My fundamental question here is simply this: besides localism, what else is there?

    From where I stand, the polar opposite of localism would have to be something called universalism.

    I guess we would then have to ask: does non-localism imply universalism? And does non-universalism imply localism?

    This is all just to ask if the concepts of semi-localism (or semi-universalism) can possibly have any rigorous sense.

    I think it much wiser to assert that the common sense notion of physical reality is not one of strict localism, but rather of a pragmatic, wishy-washy semi-localism that is crucially dependent on the context of the physical picture at hand. When thinking in terms of the objects of everyday experience, a single location will be on the order of meters. In terms of geography, it will be on the order of kilometers. Cosmologically, locations may be up to light years in extent.

    My thinking is that all notions of semi-localism are founded upon the empirical sciences. The objects of empirical science are always simply transparently given to us. This is just to say that the act of observation itself is never taken into account in any empirical science. Astronomy, chemistry, and biology are obvious examples of sciences whereby the act of observation is never at issue.

    But physics is different. While it is true that there may be many branches of physics that do indeed utilize transparently given objects, at the most fundamental level (ie Quantum Mechanics), physics is a science that has as its central question the nature of the act of observation, as such.

    My understanding is that QM is the first rigorous effort to finally come to terms with the origin of all strict localism: Newton's reduction of empirically given, semi-local bodies to their centers of mass. It is only in this way that Newton was able to handle the phenomenon of gravity using [fairly simple] analytic mathematical techniques. But I think it is safe to assume that Newton did not think that material points could possibly have any place in a fundamental description of nature.

    Once it came time to give theoretical descriptions of the elementary constituents of physical reality, Newtonian-style reductionism was no longer in the theoretical physics community's bag of tricks. But the sh*t didn't finally hit the fan until de Broglie's thesis was hailed by Einstein, and used as a source of inspiration for Schrodinger's thinking. Bohm, of course eventually joined the party. Then Bell.

    I would strictly define semi-localism as any understanding of nature that utilizes a fundamental distinction between matter and space. That is, the "material location" is taken to be everything that is contained within a simply connected surface (eg, a spherical or boxlike boundary). I find it wise to immediately discard all semi-local fundamental theories of physical reality.

    So, there seems to be either localism or universalism. We know that reality is most definitely *not* local, right?

    I will leave with the following quote from de Broglie:

    "An electron is for us the archetype of [an] isolated parcel of energy, which we believe, perhaps incorrectly, to know well; but, by received wisdom, the energy of an electron is spread over all space with a strong concentration in a very small region, but otherwise whose properties are very poorly known. That which makes an electron an atom of energy is not its small volume that it occupies in space, I repeat: it occupies all space, but the fact that it is undividable, that it constitutes a unit."
     
    Last edited: May 30, 2013
  2. jcsd
  3. May 30, 2013 #2
    Localism is just a atribute, a characteristic, a property of reality, REALITY goes beyond properties.
     
    Last edited: May 30, 2013
  4. May 30, 2013 #3
    I would call localism a property of particular models of reality; especially those kinds of models that want to make use of a Newton-esque mathematical formalism (eg, analytic algebraic equations).

    I would call semi-localism a property of reality, as it is experienced.

    I would agree that reality-as-such is beyond properties, if we think of a property as an X that is theoretically understood as a subset of universal space.

    I just feel that the problem with QM is that it continues to use the term non-local in such a way that most people will simply think of a semi-local picture. But if we instead force an explicit choice between local and universal, then we can at least eliminate entire classes of theories that do not have universally defined objects as their elementary constituents.
     
  5. May 30, 2013 #4
    Why is it necessary to define locality as localism and nonlocality as universalism and why does one imply the other?


    What properties would semi-localism have?


    You lost me here.
     
  6. May 30, 2013 #5

    DrChinese

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    Hardly. It is true that "classical" Realism is not compatible with Locality post Bell. But there are a number of non-realistic interpretations of QM. Examples are Many Worlds, Time Symmetric/Retrocausal, and even orthodox QM in many respects. These generally do not feature influences which propagate faster than c.
     
  7. May 30, 2013 #6
    I am just arbitrarily equating the terms "principle of locality" and "localism".

    The question of what, precisely, the phrase "non-local" is supposed to positively denote is what I am asking. For instance, the phrase "non-green" stills leave an infinite number of options along the entire EM spectrum.

    The reason why I say "the one implies the other" is because the notion that reality fundamentally consists of arbitrary surfaces between matter and space is simply not theoretically pleasing to me. The precise nature of this kind of "theoretical displeasure" is not very easy for me to describe, which is why I wanted to post this thread! :)

    My definition of semi-local was as such:

    The main point is that most people would never think of QM as having any stake in questions about the *universe* if its understanding of non-localism is simply a kind of semi-localism. Using this as an assumption, the range of questions that are applicable to QM will never include the range of questions that apply to the universe as a whole (such as are applicable to GR).

    So... if, for instance, the wavefunction could be seen as being necessarily applicable to the entirety of universal space, then this provides a direct entry way for QM theorists to begin framing the kinds of questions that previously have only been available to astrophysicists/comologists.
     
  8. May 30, 2013 #7
    Haha... this is precisely what I was expecting you to say! In fact, it was my perusal of that Scholarpedia article on Bell's Theorem thread that caused me to start thinking about this question. I actually read through most of that article (sans math), and found it quite refreshing.

    My understanding of the various "interpretations" of QM can be categorized as follows:

    1) de Broglie/Bohm-like causal mechanisms
    2) Bare instrumentalism (pure mathematics)
    3) Abuses of language

    I enjoyed the Scholarpedia article so much because it made no bones about the fact that those other interpretations you mention simply fail to say anything at all rather than saying things that are simply "counter-intuitive" or "hard to imagine".

    I think it is quite appropriate to quote Wittgenstein in times like this:

    (Whereof one cannot speak, thereof one must be silent.)

    All I'm saying is that I'm not interested in debating the notion of "realism", if it is structurally embedded into our language, and is what makes meaningful discourse at all possible.

    In terms of the idea of whether there can be influences that propagate faster than c, this question already assumes that the fundamental elements of reality are essentially non-universal. If this means that the elements are strictly local (ie, they occur between material points), then my contention is that we are speaking along the lines of the "Newtonian reduction" that I mentioned above, which was never meant to be a framework to aid in the theoretical understanding of the fundamental constitution of nature. But if it means that they are merely semi-local, then I would say that we are just involving ourselves in a framework that is no longer using the question of the nature of the act of observation as its guiding theme. It's an either/or thing in my book...

    Either: We are reducing empirically given material bodies to their centers of mass, in which case we are simply evading the question.

    Or: We are transparently using "real world" measuring devices in order to describe the elements of nature, in which case we aren't even aware of the existence of the question.

    In terms of a framework whose elements are strictly universal, we can at once rid ourselves of the "ghost" of Newtonian reductionism, while at the same time developing reasonable theoretical models for practical signal propagation between sources and receivers. These kinds of models do not (in fact they cannot) include things like simple particles moving in void space. They can indeed include the kinds of intuitive wave propagation models that Maxwell himself would have found agreeable.
     
  9. May 30, 2013 #8
    i agree en masse, fully.

    the term "universal" says a lot too.
    local to me, is a primitive term.
     
  10. May 30, 2013 #9

    bhobba

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    Errrr. Not quite - eg Many Worlds is not pure mathematics nor is it an abuse of the language. And that's just one example here is another - Consistent Histories:
    http://quantum.phys.cmu.edu/CHS/histories.html

    Can I ask where you got such an idea from?

    Thanks
    Bill
     
  11. May 31, 2013 #10

    DrChinese

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    Sadly, the Scholarpedia article has a explicitly Bohmian take on Bell. Travis Norsen and several others did a number on that, effectively mixing some good material with other which represents a bias not generally accepted in science. Your refusal to discuss the significance of Realism in Bell is probably influenced by that. Travis does not acknowledge Realism as a requirement to the Bell result. On the other hand, this is almost universally acknowledged by researchers in the area.

    Specifically, most physicists would say that the outcomes of experiments are observer dependent ("contextual"): there is no independent reality to non-commuting pairs of observables. I believe this is probably a viewpoint shared by most Bohmians, Travis being an exception. Once you acknowledge this, interpretations such as the MWI and Time Symmetric types seem to be reasonable options.
     
  12. May 31, 2013 #11
    Actually, Travis is not an exception to this rule. He agrees, as a matter of ideology, that you cannot have reality corresponding to two non-commuting observables. After all, Bohmian mechanics only ascribes reality to position. But, as you said, somehow he claims that realism isn't essential for Bell's theorem.

    For the benefit of others (you already understand all this), here is my post from the old Scholarpedia thread where I identify what I think is the problem with Travis' argument. Basically he's implicitly invoking counterfactual definiteness, AKA realism.
     
    Last edited: May 31, 2013
  13. May 31, 2013 #12

    really, you have to define locality/non-locality just like subsets of contextuality/noncontextuality,
    contextuality is broader, subsumes locality/nonlocality.
    that every state that is contextual with respect to the defined test of contextuality is nonlocal as per the CHSH (Clauser, Horne, Shimony, Holt test) but the converse is not true, or as i like to ask:

    Every state that is contextual is nonlocal.
    ...and the inverse, is every state that is nonlocal is contextual ?


    -----
    measured values (atributtes, characteristics, properties) in context, just is related to that, "context", be real goes beyond properties, the possibility of values requires pre-existent objects or process, without objects, there is no possibility of properties (values).
     
  14. May 31, 2013 #13


    Your language is confusing, e.g. you could have used the standard phraseology typical for such a topic and used - "Does non-locality imply holism?" instead of "does non-localism imply universalism?"








    I still fail to see what semi-localism is supposed to be and how it's expected to account for the perfectly local macro reality. But there is no contradiction between locality and the implied non-locality of qm as soon as you understand that the observed local macro reality is a subset of the wider quantum reality, experienced as it is due to your experiential interaction with it.


    "Dephasing in electron interference by a 'which-path' detector":

    http://www.nature.com/nature/journal/v391/n6670/full/391871a0.html


    Physics concerns itself with issues of practical purposes, so for all practical purposes locality can be considered to be intact. For the more philosophically-minded, 'observer' and 'observed' are hard to separate, hence locality and non-locality are equally 'real' and equally there and there is no issue between them. So if by 'universalism' you mean reality as it's experienced, I would say that non-localism hints at universalism.
     
    Last edited by a moderator: May 6, 2017
  15. May 31, 2013 #14

    DevilsAvocado

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    If you just could elaborate on what this epic transition from non-locality to universalism will do in terms of scientific values – I would be more than happy.

    (audioloop seems so universal epiphany happy, I’m jealous)
     
  16. Jun 1, 2013 #15
    What is universalism?

    Can you define it with a positive definition rather than, "...the polar opposite of localism would have to be something called universalism"?

    I think you jump too quickly into the semi-localism discussion before telling what universalism assumes, implies, infers, and entails...

    Let's pin that down first.
     
  17. Jun 1, 2013 #16
    I read the responses, and just decided to write one big free-flowing response to everyone at once...

    The entire reason anyone knows about Bell in the first place is just that he wanted to blow the lid off of von Neumann's crusade against an independently subsisting reality that is otherwise known as "hidden variables". Bohm was influenced by Einstein in terms of the idea that if the term "physics" is to have any meaning, then it must be referring to the causal mechanisms (ie, universally applicable principles) that determine how nature functions. And Bell was influenced by Bohm.

    The idea that Einstein really gave a hoot about SR-esque localism when it came to fundamental physical theory is just untrue. He cared deeply about the idea of causation. He absolutely despised the idea that a fundamental description of nature is necessarily probabilistic. And I would say that he despised it *not* because of some kind of arbitrary, innate prejudice. It is because statements of the form "X happened because it was probably going to happen" is not any kind of statement at all. It is simply an abuse of how we use the term "because".

    The reason why von Neumann wanted to dispense with discussions about an independent, objective reality in the first place is because its nature cannot possibly be finally verified through necessarily subjective experimentation. But this is precisely the reason why Einstein liked it so much. Einstein was an "imagineer" of the highest caliber. He most certainly had very little interest in experimental confirmation, although he certainly had to pay lipservice to it.

    Never before had physics tried to understand the mechanisms underlying the interface between light and matter. But light, as such, cannot possibly be "seen", and neither can "matter". For whatever reason, objects are presented to our intuition via the faculty of sensation (Kant's terminology). In order to develop foundational theories of light and matter, therefore, we are going to have to descend into a purely theoretical realm.

    But since science had never been purely theoretical (at least, not *modern* science), there was a natural resistance to the turn to pure theory. Given that all possible classical, observation-based theories had pretty much [arguably] already been done, the only thing left to do was to develop a "meta theory" about physics, as such. The new theorists were then tasked to develop a framework in which the irreducible elements of reality are "acts of observation", or "observables". In other words, rather than being a theory about the measures of independently subsisting constituents of nature, QM ultimately became a first order theory about measurement, in itself.

    So, let's think about this. The essential idea of canonical QM is just that there are categories of "observables", that are arranged by groups of "quantum numbers", such as charge and spin. But there is still the inevitable implicit assumption (due to the nature of language itself) that physical theory is about independently subsisting elements of nature. Because of this assumption, the names that we have given to certain classes of observables (electrons, photons, etc) are mistakenly thought by many to be references to elements of nature (ie, physical things).

    But observables are the irreducible elements of QM. There is no possibility of a mechanism to connect observables, if mechanisms are things that theorists invent after they have made their observations. Let me emphasize this point: QM, as we know it, is about the act of observation, and nothing else.

    In lieu of imaginatively devised causal mechanisms, the only way to speak about "why" certain observations are made is to invoke the spectre of probability. Furthermore, the probability for any particular observation can never be 1, because this would imply certainty, which would itself imply the need for some kind of deterministic, causal mechanism.

    Each of the preceding remarks must be fully appreciated before we start speaking about the non-Bohm-like interpretations of QM (assuming that keeping a purely mathematical relationship to the QM formalism is not truly an interpretation.) Anything that speaks not about *this* world, but "many worlds" violates the necessary definition of physics that it is an investigation of a singular, collectively experienced natural order (rather than of some number of imaginary, parallel natural orders). And anything that speaks about effects that precede causes violates how the concept of causation is structurally embedded into our language.

    So, we speak about physics being about the causal connections between things in a single universe *not* because we are making some kind of arbitrary choice based upon "personal taste", but because the very structure of language, as a reliable mechanism for communication, enforces it upon us. And since physics *is* about the causal connections between things, we have to start developing imaginative pictures about what constitutes a "thing", and the principles that govern their interactions in order to start making new headway.

    The ultimate point of the original post is that physical theory can either speak about the locations of things (ie, their centers of mass), or about the forms of things. We already have well-defined theoretical "pictures" of what fundamental elements of reality might look like, and those are the "atomic orbitals" that every Intro to Chemistry texbook shows. But rather than thinking of them, naively, as objects of microscopic proportions, I propose that the only reasonable thing to do is to think of them as being universally defined. This is just to say that the semi-local picture that chemistry students have of atoms is based purely on the idea that atoms can be definitively measured, just like the objects of the other empirical sciences. But they cannot be. Atoms are purely theoretical constructs that are meant to give reasonable models for how the material complexes (eg, gases, crystals, organic chains, etc.) of the higher level chemistry-based sciences form. But there is no a priori reason why they can't also be used as models for how, for instance, things like cosmic-scale gravity fields form. That, in a nutshell, is my whole point here.
     
    Last edited: Jun 1, 2013
  18. Jun 2, 2013 #17

    bhobba

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    Einsteins views of QM changed quite a bit over time. At one time he made comments like God doesn't play dice with the universe but that was not his primary concern during his later years. You can read it in the introduction to Bohm's book on QM - he wrote a well respected standard textbook prior to Bohmian Mechanics and Einstein wrote a forward to it explaining his view. He believed QM was correct - just incomplete. He did not believe in a world created by observation - for him it existed independent of whether it was observed or not - that was his main concern.

    Here is a good paper I found of what Einstein really thought:
    http://www.scientiaestudia.org.br/associac/paty/pdf/Paty,M_1995b-NatEinsObjQM.pdf
    'Later on, he would consider that quantum mechanics is free of inner contradictions but is incomplete. It is in trying to show this incompleteness by physical arguments that he made explicit the non-local character of physical systems as described by quantum mechanics. We notice, in such attempts, that incompleteness, in Einsteins's view, is not merely to be identified a priori with indeterminism and the statistical character of the description. We shall emphasize further that Einstein's motivation was not primarily to restore determinism against probabilistic description, but to point out non-locality as a defect of the formalism which lets us with only a statistical description.'

    I think anyone that has seen pictures of atoms using scanning tunneling microscopes or even being exposed to Brownian motion will likely hold a different view.

    I have a few more comments I could make, but personally I don't, and never have thought, philosophical analysis is the way forward on QM issues. For example in the last few decades decoherence has been much better understood and has has a lot to say on interpretations. IMHO it is fully working out the consequences of this very rich, interesting, and mathematically very beautiful theory (as an aside, and I dont quite know why it is, we don't see a lot of posts about just how mathematically beautiful this theory is eg symmetries determine dynamics - that's really mind blowing when you think about it) theory that is the way forward. There have been some hints that string theory for example may have something to say on fundamental issues in QM - but it really is early stages.

    One thing that I never have been able to get out of my mind is maybe there is a connection at a very deep level between the MWI and Eternal Inflation.

    Thanks
    Bill
     
    Last edited: Jun 2, 2013
  19. Jun 2, 2013 #18
    Was this quote meant to be an example of abuse of language? Clearly the uncommunicable object of the quote is being communicated about in the very quote itself. The abstraction is yet a contradiction.

    The proper form for this type of statement must truly be a blank line (written silence)?
     
  20. Jun 2, 2013 #19

    DevilsAvocado

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    glengarry, it’s always great to think ‘out of the box’, and at the same time it’s sometimes easy to get blinded by your own ‘splendid ideas’. Perhaps I could help you see things that maybe aren’t ‘enlightened’ enough in your reasoning.

    As bhobba points out, Einsteins views changed over time, and it isn’t always easy to sort it all out. Recommended reading (beside bhobba’s):


    Okay, so if I toss a coin for left/right, it’s an “abuse” to say – “We are going to the right because we got heads”...?

    Forget words like ”finally” etc, science is not about the final ultimate truth. That’s for the priests in the Vatican.

    Well, “lipservice”... when Einstein heard of Hubble's discovery, he said that changing his equations was "the biggest blunder of his life"...

    Courtesy of the Archives, California Institute of Technology

    Isn’t this is a bit ‘dramatized’? Are you saying that when Newton in 1717 studied the interference pattern in “Newton's rings” – and came to conclusion that light is composed of particles or corpuscles – this is “classical, observation-based theories”, and when Richard Feynman et.al. formulated QED looking at exactly the same problem – this is a “purely theoretical realm”?

    420px-Newton_rings.jpg

    The funny thing is that QM theory says absolutely nothing about what happens at measurement... interpretations yes, but that’s a completely different story. And besides, not one Nobel Prize in Physics has been given without empirical evidence, not one (ask Stephen Hawking).

    I agree that the “language of QM” is not the peak of precision with words as “system, apparatus, environment, microscopic, macroscopic, reversible, irreversible, observable, information, measurement” etc. and J.S. Bell had a lot of intelligent remarks on this. But how could QM only be about “the act of observation” when it’s not specified in the theory = The Measurement Problem...

    Sure it can, two polarizers set aligned or orthogonal will give probability 1 or 0 every time, guaranteed. Work for QM & Classical.

    I agree the interpretations are not exactly “The Jewel of Physics”... some are just crazy. But at the same time – who says that nature is made to make us happy (about the logic)? I don’t like MWI, but what is “*this* world”? We know we aren’t the center of universe, and we’re restricted to our “observable bubble”, which means there must be other “*this* world” out there that we will never ever get in contact with, right?

    I agree to some extent, with the caveat that it’s not guaranteed that nature is ‘the way we wish for’. It’ could be ‘weird’, and if so – we just have to accept it.

    I don’t agree. If you bombard gold atoms with gazillions of electrons in a modern scanning tunneling microscope, this is the picture you get:

    Atomic_resolution_Au100.JPG

    Is this fake? Is it false?? Of course not, it’s the classical state of the QM world, right there. To me the next ‘paradigm’ in physics might be to exactly find and define (what Bell calls) “the shifty split” – that is, the division between “the quantum part” and “the classical part.

    When we do that, we will get rid of most of the terrible interpretations, and get a much better understanding on what’s really going on... I think...

    Hum... gravity, well that’s TOE... that’s a BIG jump for Bell’s theorem, but who knows, who knows...
     
    Last edited by a moderator: Apr 15, 2017
  21. Jun 2, 2013 #20

    DevilsAvocado

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    Thanks bhobba, very nice.
     
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