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Just a quick question about the double slit experiment.

  1. Oct 19, 2012 #1
    If electrons are shot through the double slit one at a time, is it observed that each electron hits randomly in one of the dense areas of an interference pattern, or is it only observed after a long time that the interference pattern emerges?

    To rephrase, what I'm asking is whether a single particle hits the wall in many places at once in the form of an interference pattern, like you would observe from a single wave sent through, or whether each individual particle only hits a single random spot on the wall and the pattern emerges after many repetitions.
    Last edited: Oct 19, 2012
  2. jcsd
  3. Oct 19, 2012 #2
    pattern emerges after many electrons are shot. Each electron makes one mark on the screen.
  4. Oct 19, 2012 #3


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    See this animation of an interference pattern as it appears on the screen. It starts out slowly, one spot at a time, then speeds up so you don't have to wait an hour or so to see the pattern take shape.

    Last edited by a moderator: Sep 25, 2014
  5. Oct 19, 2012 #4


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    I think it would help if you think about it in a different way. A single electron can end up anywhere and the result is totally random. The probability of where it will actually hit depends upon the statistics. The probability distribution is the same shape as the interference pattern. Very unsatisfactory, I know, but that seems to be the way it is.
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