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A question about the double slit experiment

  1. Jul 5, 2012 #1
    Just a thought. In the double slit experiment, is it possible that the particles don't actually interfere with themselves, but rather they encounter interference from all the other particles which either already have been, or subsequently will be sent through the experiment. After all, for the results to show a definite pattern it is necessary to pass many particles through the apparatus, and although the setup displaces each particle in time, it doesn't displace them in space. They all occur in the same place, but at different times. But if the particles exist outside of time, then not displacing them in space means that they will all be passing through the experiment at the same time. Perhaps if the experimenter moved the apparatus inbetween each particle then the interference pattern would disappear.
  2. jcsd
  3. Jul 5, 2012 #2

    Simon Bridge

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    Short answer = no.
    "Interference" in the 2-slit experiment is an emergent property of the underlying dynamics.

    Note: we can do the experiment at arbitrarily low rates (in principle - we could send one particle through the apparatus a year, say, or a decade, without affecting the emerging pattern). How does a particle released today get interfered with by a particle that gets released many years from now? What happens if we change our mind and discontinue the experiment after releasing only one particle?

    "The apparatus" is the source+screen+slits ... makes no difference.

    The slits act to measure the position of the particle, which makes it's momentum uncertain in relation to how precise the measurement is. The system ends up in a superposition of states - one for each slit - which tells us the details of how the momentum is uncertain. It is this that produces the appearance of interference.

    See ]Marcella T, Quantum Interference with Slits for a complete treatment.
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