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Oh no not another thread on the 2 slit experiment!

  1. Mar 8, 2006 #1
    http://www.fortunecity.com/emachines/e11/86/qphil.html [Broken]

    I was wondering if anyone knows of any other interpretations of the classic two slit experiment other than the Copenhagen interpritation, I've heard there there is a Bohmian interpretation(anyone know anything about how the wierdness is explained in this) but I can't seem to find any other ideas, although this article mentions a few. Anyone got any whacky ideas of their own, or interpritations that might explain this wierdness in different ways. For example you could say that the act of observing the wave itself interfers with it and makes it behave in a particular fashion(If you'll pardon the virtual pun:smile:) the "colision" or detection disturbing it and making it behave as a particle? Anyone seen any other interesting interpritations even if they are as far fetched as the many worlds one or my one?
    Last edited by a moderator: May 2, 2017
  2. jcsd
  3. Mar 8, 2006 #2
    grrr.. the article says "photons... are like particles and like waves..."

    No they are neither. They are described by ket vectors in a hilbert space! And all physical observables are represented by Hermitian operators acting on that space.
  4. Mar 8, 2006 #3

    This is probably a better web site.

    The whole thing is pretty bizarre in that you can never really exactly see what is going on without destroying the interference itself. So in a science so used to inference, even the fundementals have to be infered, for all we know it may be not just be neither a wave nor a partice nor a warticle but something even more bizarre than that? But how could we be sure?:eek:

    EDIT: honestly I ask because I can't find descriptions of other interpretations on the net, or at least not very good ones, if someone can enlighten me, I'd apreciate it.
    Last edited: Mar 8, 2006
  5. Mar 8, 2006 #4
    I agree with masudr's point of view. If we try to think of electrons as either a wave or particle, we just get lost. Thinking of them as something completely new is probably the better way to look at it.

    I've never heard of a "Bohmian" interpretation...I'll have to Google it. There is, as you mentioned, the Copenhagen version. The only other one I know of is "Many Worlds Theory" which unfortunately (as far as I know) gives EXACTLY the same answers as the Copenhagen. (Quick rundown: Every time the Universe makes a quantum level "decision" the entire Universe splits into as many copies as there are quantum options. The electrons interfere in the 2-slit essentially due to the interference of two similar Universes being right next to each other, or some such argument.) I don't find it to be a good theory in that regard, because it doesn't make a new prediction. However there HAS been a flurry of activity in recent years over parallel universes, so maybe...

  6. Mar 8, 2006 #5


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    Here's a good general page on Bohmian mechanics:


    Wikipedia entry on Bohm's interpretation:


    This one talks a little about how Bohm's interpretation would analyze the double slit experiment:


    This page talks about how you'd understand the Aspect experiment with Bohm's interpretation:

    Last edited: Mar 8, 2006
  7. Mar 8, 2006 #6


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    If I may attempt to respond (and then be subsequently corrected by Vanesch! :smile:)...

    MWI attempts to take QM seriously -- if a particle is in a superposition of states, then fine, it's in a superposition of states. Any realistic "measurement" should subsequently wind up with the measuring device being entangled with the particle.

    The hypothesis that a measurement "collapses" the wave function to provide a definite outcome is simply an ad hoc patch to the theory for people who like definite outcomes! (Or, more accurately, a mathematical tool for computing conditional probabilities)

    Note that there are things that we can describe quantum mechanically that act like measuring devices, (e.g. a quantum computer), and they do get entangled with whatever they're measuring. So why should a "classical" measurement be any different?
  8. Mar 8, 2006 #7
    What interpretation does http://video.google.com/videoplay?docid=-4237751840526284618&q=quantum&pr=goog-sl [Broken] fall under? :biggrin:

    Here is the wikipedia article with the different interpretations:


    If u scroll down 2/3rds then there is a nice little overview.
    Last edited by a moderator: May 2, 2017
  9. Mar 8, 2006 #8
    The annoyingly enthusiastic voice also tries to initially pass of electrons as "tiny marbles if you like." Furthermore, the video showed each individual electron as a particle at all times -- of course this is ridiculous, and we should all know the electron has no well defined position unless it's in a position eigenstate, and also that the electron is described by kets.
  10. Mar 9, 2006 #9
    Thanks guys this was exactly the sort of thing I was looking for :approve: :smile:
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