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What is the opposite of realism in quantum mechanics?

  1. Jan 19, 2012 #1
    What is the opposite of "realism" in quantum mechanics?

    I have been spending an awful lot of time reading about the philosophy of science where the opposite of "realism", insofar as "realism" constitutes a category coherent enough to be meaningfully negated, is "anti-realism". Is this true as well in quantum mechanics?

    Neither "local anti-realism" nor "local non-realism" nor permutations of variations thereof return very many search results, certainly many less than "non-local realism" and permutations of variations thereof. Am I using the right terminology for theories that relax various criteria for reality/realism in quantum mechanics? Or is there really just not a whole written on theories that relax the reality criteria?
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  3. Jan 19, 2012 #2
    Re: What is the opposite of "realism" in quantum mechanics?

    I am mostly interested in terminology, so I find out about local non-realistic theories. However, given the vagueness of the title, I am open to also discussing the mathematical formalisms that make the idea of realism rigorous and falsifiable.
  4. Jan 19, 2012 #3


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    Re: What is the opposite of "realism" in quantum mechanics?

    "Non-realistic" is a way better term than "anti-realistic".... But if you're looking for search terms, try:

    Copenhagen interpretation
    Bell's theorem
    EPR paradox

    And you'll find plenty of material.
  5. Jan 19, 2012 #4
    Re: What is the opposite of "realism" in quantum mechanics?

    You won't find a lot about theories like that because they aren't especially viable. The term "local realism" comes from the assumptions made in Bell's derivation of his orginial inequality. However, as Bell himself pointed out soon afterwards, relaxing the assumption of realism doesn't really change anything.

    Most variations on Bell's inequality do not assume realism, and still demonstrate quite clearly that quantum mechanics is nonlocal (barring loopholes).
  6. Jan 20, 2012 #5


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    Re: What is the opposite of "realism" in quantum mechanics?

    Realism is the idea that, when we make an observation, we observe something that "really" exists even without our observation.

    You may also want to read this:
    http://xxx.lanl.gov/abs/quant-ph/0607057 [Foundations of Physics, Vol. 37 No. 3, 311-340]
  7. Jan 20, 2012 #6
    Re: What is the opposite of "realism" in quantum mechanics?

    Realism is the idea that reality exists independent of observers and naive realism is the idea that we perceive objects as they really are. Both are challenged by the experimental evidence of quantum mechanics and it isn't merely a question of local verses nonlocal realism either.

    The latest theories and evidence in quantum mechanics suggest reality is contextual, that is, reality has no demonstrable meaning outside specific contexts. For example, whether the earth looks flat, round, a dimensionless point, or nonexistent just depends on how far way we are. The reality of the earth's existence then can be said to be context dependent and if it has any reality independent of our context such speculations are outside the purview of science.
  8. Jan 20, 2012 #7
    Re: What is the opposite of "realism" in quantum mechanics?

    You're mixing a number of terms. Realism broadly asserts that all that exists includes the observers, materialism broadly asserts that all that is matter or energy -and is a form of realism,- idealism asserts that all is mental, and contrasts realism.

    Locality and non-locality are views on whether only local phenomena can explain certain 'linked,' or entangled, quantum states, a side effect of a mathematical theory on minute phenomena in nature.

    Most physicist are both realist and materialists. Locality has little to do with either view, so non-local realist asserts someone who favors a certain explanation of quantum phenomena and has a realist/materialist explanation of the world. One might also be a local, or non-local, idealist - locality and realism are orthogonal concepts.
  9. Jan 21, 2012 #8
    Re: What is the opposite of "realism" in quantum mechanics?

    Here are 2 other interesting papers by Gisin on this issue of realism with a few interesting quotes:
    Non-realism : deep thought or a soft option ?
    Is realism compatible with true randomness?
  10. Jan 22, 2012 #9
    Re: What is the opposite of "realism" in quantum mechanics?

    Ancient and somewhat deficient, but still capturing some of the essences of modern day philosophical conundrums on realism(talking about the Hindu philosophy of Advaita Vedanta):



    It doesn't reject materialism and the material world, yet it says it's not completely real in all senses either. And termed as it is, it seems impossible to refute with modern day evidence.
    Last edited: Jan 22, 2012
  11. Jan 22, 2012 #10


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    Re: What is the opposite of "realism" in quantum mechanics?

    One thing to note is that "realistic" in "locally realistic" is a different word than "realism", and is referring to a different idea. (and, of course, is also a different word from its homonym "realistic" in layman's English)

    Realistic interpretations are the exception in quantum mechanics; generally speaking, most scientific material you will read on the topic is not realistic. You have to go out of your way to find realistic interpretations; the most prominent, I think, is Bohmian mechanics.

    Roughly speaking, realism says that the quantum state refers in some sense to an actual object in the real world, and that one can do an experiment with it whose outcome we call "position". "Realistic" says that "position" is an actual property of that object, rather than merely an outcome of an experiment.
    Last edited: Jan 22, 2012
  12. Jan 22, 2012 #11
    Re: What is the opposite of "realism" in quantum mechanics?

    Science isn't about disproving metaphysical suppositions, the existence of God, or anything else for that matter. Its about what is demonstrable and in the case of metaphysics that means how they can be self-consistent and possibly useful for practical applications. Personally I think all metaphysics is so much gibberish that occasionally turns out to be useful. No more or less meaningful then anything else without a specific context to give them meaning.
  13. Jan 22, 2012 #12
    Re: What is the opposite of "realism" in quantum mechanics?

    I agree with all of what you say, however 'meaning' is as much out of the bounds of science as is the purported existence of god or our attempts at understanding an otherwise incomprehensible reality. While we are at that, everything has become out of the bounds of science and relegated to metaphysics these days(save for a handful of mathematical rules for predictions and a general model of the world that we don't know and understand how to save from becoming ever more phenomenal). If in doubt, ask why this thread got moved here. With that in mind, there is no absolute guarantee that the prevalent methaphysics and models of the world of today will be useful tomorrow and to what extent.
    Last edited: Jan 22, 2012
  14. Jan 22, 2012 #13
    Re: What is the opposite of "realism" in quantum mechanics?

    Thanks for all of the responses.

    I have busied myself reading some of the publication provided, and am trying to formulate a explanation that refines the questions I asked in the OP.
  15. Jan 22, 2012 #14
    Re: What is the opposite of "realism" in quantum mechanics?

    Meaning can be as demonstrable as anything else and well within the bounds of science. Being a pragmatist myself I couldn't care less what science adopts and discards so long as it is useful at the time. For all I know that is the fate of science, to constantly evolve along with its context. In fact, the alternative sounds rather unappealing.
  16. Jan 25, 2012 #15
    Re: What is the opposite of "realism" in quantum mechanics?

    That 'meaning' can mean very different things to different people. It's not known to me that there exists anything at all in this reality that has an inherent meaning. On the contrary, we give everything we do meaning, in other words, meaning in and of itself DOES not exist. Hence, science cannot discuss meanings, because scientists and people give meaning to the studied subjects. In that respect, meaning is very different than mass, velocity, charge and other observable characteristics.

    I am not aware of there having ever been a greater confusion in the minds of scientists wrt to the world at large, than that of today(maybe in the stone age?). While i find it more likely that reality wasn't designed(based on the fact that most of things in the past that looked designed were found to not be), i can't completely hand-wave arguments to the contrary, as science is plagued with deep conceptional problems - from who/how/what makes decisions in neural circuits in the brain(neurons firing), to the nature of matter, time and space(and even who and what exists). I don't know of a single category of our scientific enquiries whose validity hasn't been questioned by authorities in theor fields(that sadly includes realism in all of its varieties). In that respect, i find the ideas in the ancient Hindu philosophies i linked above more flexible and slightly more compatible with the requirements of no-go theorems than the rock-solid stereotype of the world found among pedestrians on the street. And let's face it, if the wave nature of matter turns to be real(as in the sense of realism as it is generally understood by physicists), this will be a very big, if not the biggest, challenge facing physics and physicists(a nasty surprize too).
    Last edited: Jan 25, 2012
  17. Jan 25, 2012 #16
    Re: What is the opposite of "realism" in quantum mechanics?

    It doesn't matter whether people have two different meanings or whatever. Science is only interested in what is demonstrable and if it can be demonstrated they have two different meanings that's good science. Essentially no different then a dictionary having multiple definitions for the same word, yet people manage to communicate effectively nonetheless.

    Habits are the end of compassion and honesty,
    The beginning of confusion;
    Lao Tzu

    I couldn't care less about the "reality of the matterwave" or whether scientists are confused or Joe sixpack is shallow or Hinduism can make the world a better place or whatever. Metaphysics, theology, and psychology are not branches of physics and the only issue on the table is what the physics of quantum mechanics has to say about realism.

    Please stick with the topic.
  18. Jan 25, 2012 #17
    Re: What is the opposite of "realism" in quantum mechanics?

    I hate to point out this obvious fact, but if the topic landed here, it obviously(physics) didn't have much to say about realism. I am also certain that anytime you or anyone else discussed propositions about realism in pseudo-physics terms(you couldn't in any other way), the topic would be moved to personal philosophies(i.e. here). You have to be aware of the difference between physics and metaphysics and when one turnes into the other.
    Last edited: Jan 25, 2012
  19. Jan 25, 2012 #18
    Re: What is the opposite of "realism" in quantum mechanics?

    Physics deals with what is demonstrable and can therefore describe whether the accepted theories and evidence appear to be particularly compatible or incompatible with any metaphysics.
  20. Jan 28, 2012 #19
    Re: What is the opposite of "realism" in quantum mechanics?

    Going by this rule, realism at the quantum level can be considered dead. My own opinion changed a few times through the years on this, based entirely on my own philosophical considerations. To my knowledge, the best test of quantum realism has been carried out by Nobel Prize winner A.Legget and Zeilinger in 2007:

    "It took them months to reach their tentative conclusion: If quantum mechanics described the data, then the lights’ polarizations didn’t exist before being measured. Realism in quantum mechanics would be untenable."

    "A team of physicists in Vienna has devised experiments that may answer one of the enduring riddles of science: Do we create the world just by looking at it?"

    “But to give up on realism altogether is certainly wrong. Going back to Einstein, to give up realism about the moon, that’s ridiculous. But on the quantum level we do have to give up realism.”"

    This is very puzzling, how can classical realism survive if quantum realism failed?

    Also, this paper and test by A.Zeilinger claims to show that which-path information changes which aspect of matter will be observed(wave-like or particle-like) which would be direct demonstration that a mind-independent world does not exist(since mind and information, which is solely a property of minds, affects the behavior of matter at the micro scale):

    Last edited: Jan 28, 2012
  21. Jan 28, 2012 #20
    Re: What is the opposite of "realism" in quantum mechanics?

    Just because realism is all but dead in quantum mechanics doesn't mean panpsychism or whatever is the most likely alternative. Before his death John Wheeler suggested a theory of everything might turn out to be just an equation with no clear metaphysical underpinnings whatsoever. It ain't over until the fat lady sings and right now we have plenty of other evidence for other metaphysical positions as well.
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