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Double slit experiment target

  1. Mar 9, 2006 #1
    Hi! :smile:
    I’m new here and enjoying it very much.
    In the double slit experiment; what causes the fired electron to change from being in a wave configuration, back to a particle configuration when it strikes the target?
  2. jcsd
  3. Mar 10, 2006 #2
    The electron is neither in a particle state, nor a wave configuration, until it is observed. If you try to observe the electron while it is in flight:

    1) Trying to observe the electron as a particle will measure that the electron is a particle, hence no interference pattern.
    2) Trying to observe the electron as a wave will measure that the electron is a wave, hence we get an interference pattern.

    Don't you just :!!) how much confusion this simple experiment can generate?


    Sorry, I should have mentioned that I am presuming that we are observing the electron at one of the slits.
  4. Mar 10, 2006 #3
    I think he meant when the elctron strikes the detector. Let's assume that's the case.

    This a crazy thing man: the wavefunction never collapses if you didn't ascertain which slit the particle went through! The electron exhibits particle behaviour, having struck at a point, and yet over many electron observations you can only explain *where* the electron hit if that same electron *upon striking the the target* is also exhibiting wavelike properties!

    So the answer to your question is that the change in "configuration" never happens unless you ascertain which slit the electron must have gone through.
  5. Mar 10, 2006 #4
    I think my brain has started leaking out of my ears. The quantum world, we don't really understand it but we'll be damned if we'll admit it :wink:
  6. Mar 10, 2006 #5


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  7. Mar 10, 2006 #6


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    On the contrary, the Copenhagen interpretation is based precisely on this admission.

    Sorry about extending a profitless thread, Zapper, but I couldn't resist.:redface:
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