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How does string theory describe the wave/particle duality of matter?

  1. Jun 9, 2004 #1
    As the title implies, how does string theory describe the wave/particle duality of matter and the forces? How does it describe the double slit expirement? Thanks for the replies.
     
  2. jcsd
  3. Jun 18, 2004 #2
    String Theory and The Quantum Measurement Problem?

    I was going to start a new thread myself to basically ask the same question. But since you've already asked it I'll just add my question to yours.

    Does String Theory address the "instantaneous" collapse of the wavefunction?

    From what I can tell so far it doesn't. I've read Brian Greene's "Elegant Universe", I saw his video, and I am currently reading his book "The Fabric of the Cosmos". I haven't quite finished this most recent book yet.

    But as far as I can tell String Theory has nothing at all to say about the quantum measurement problem. All the hoopla about string theory seems to be about the fact that it promises to possibly incorporate GR with QM.

    And from what I can tell about that, the only reason that it incoporates GR is because strings have dimension, and therefore we simply can't apply the equations of GR below a certain size. So rather than truly melding the two, string theory just explains why GR and QM can't be melded together. Isn't that correct?

    That certainly appears to be what Brian Greene is saying in his lastest book.
     
  4. Jun 18, 2004 #3
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    From the book Quantum Evolution by McFadden it can be read that wave-particle duality (quantum superposition/uncertainty principle) are "fundamental to quantum mechanics, yet remain one of science's strangest aspects." One has to wonder how particles that have a discrete size and shape can "unwrap" themselves to travel through space as a diffuse wave passing through different points simultaneously. It seems to me that what strings imply is a connection between the mysteries of being in two places at one time and string theory. With strings there is the chance that we could be living on an isolated membrane that prevents us from seeing the "other slices of the loaf of bread." (Like Brian Greene talked about) But, there is also the fact that through gravity (a proposed non-contained force) we could connect to distant parts of space. I would say that there is a connection between the string theory and particle-wave duality because it implies the possibility that particles (eg photons) travelling say for example from the sun (8 minutes away) have the ability to change their trajectory based on a human observer because of the fact that they are harnessing the power of strings. This is a total assumption.. but I've been thinking about it for sometime.. I too haven't found much info on the connection of the two ideas.. but I'm thinking it has something to do with the supersymmetry involved in string theory and the way quantum mechanics is seemingly chaotic (like the example of the double slit experiment) absent of string theory.

    as for the second question.. I have no clue on that one. However the further one gets from a string the more it looks like strings are the exchange of vector bosons between particles.. so maybe what string theory is predicting is the fact that because a closed loop string has no mass it looks similar to a spin 2 vector boson.. or what was once theorized as being a "graviton." This is how it connects quantum mechanics to relatvity... but... I'm not sure on that.. it seems to me that even a closed loop string could become an open ended one... but where would it gain it's light speed endpoints (quarks?) I don't know.
     
  5. Nov 14, 2006 #4

    Demystifier

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  6. Nov 14, 2006 #5

    selfAdjoint

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    You don't have to go all the way to Bohm to believe that the "wave function" and the whole Hilbert space/operator formalism is a useful model, but not a fundamental assertion of quantum mechanics.

    "Particles" in string theory are wavelike excitations of strings. They seem particle-like only because the strings are so small. So there's the SST take on "particle-wave duality". As for the wave function, strings are quantized according to the same kind of operator/Hilbert space formalism that's used in other parts of quantum mechanics, and presumably have the same difficulties with the measuremnt problem.
     
  7. Nov 15, 2006 #6

    Demystifier

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    The point is that it is widely accepted that string theory does not say anything NEW about the interpretation/measurement in QM. In contrast, in the paper above I suggest that it might.
     
  8. Nov 15, 2006 #7

    vanesch

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    As anti-dote, I would suggest you also read Lee Smolin's The Trouble with Physics, or Peter Woit's Not Even Wrong. Otherwise you'll get a Yin-Yang imbalance :biggrin:
     
  9. Nov 15, 2006 #8

    vanesch

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    Then what is a fundamental assertion of quantum mechanics ?
     
  10. Nov 15, 2006 #9

    Demystifier

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    If string theory is really the theory of everything, then it must also say what the fundamental assertion of quantum mechanics is.
     
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