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Single slit experiment and HUP

  1. Mar 20, 2006 #1
    In QM a photon with wavelength comparable to the width of a slit, will pass through and create a 'Gaussian Distribution' on a screen. As the slit width is decreased (gets thinner), the 'GD' on the screen will counterintuitively INCREASE (aka. widen). My question is it possible that the slit wall thicknesses themselves are the cause of this effect? How does slit wall thickness effect the GD on the screen when all other variable are held constant?

  2. jcsd
  3. Mar 20, 2006 #2
    With or without HUP as the slit becomes narrower, more of the total light going though it is spread out wider.
    How wide can be limited by the thickness of the “wall”. A razor thin wall with a very thin slit say 3 to 4 wave lengths wide, should produce some photons “turning” 600 or more. A full ½-pi turn in theory could be produced by an infinitely thin wall.

    For a fun applet on the single and double slits where the screen observations are measured in radians (for a curved screen):

    http://www.physics.northwestern.edu/vpl/optics/diffraction.html" [Broken]

    It assumes a infinite thin wall, and allows some light to go through even if the wave length is larger than the slit width, neither of which is realistic, just the formulas to the extremes.
    Last edited by a moderator: May 2, 2017
  4. Mar 21, 2006 #3
  5. Mar 22, 2006 #4
    NO the idea that the single slit experiment some how provides validation of HUP is what “makes not sense”. You’re not understanding the experiment if you think that.

    You get the identical wide distribution of light with lots of photons going thought the one slit together (explain that classically without HUP) as you do when you send one photon at a time though the slit – not so easy to explain that one classically.
    A weird and unexplainable result, that HUP is used to explain!
    To turn around and then claim the same result you were explaining is proof or validation of the explanation doesn’t cut it.

    The only experiments that can be looked at as a validation of HUP-QM are the EPR-Bell proofs. And not everyone agrees that those are conclusive, but the majority do accept them.
    Other experiments are just paradoxes resolved by accepting the HUP-QM interpretation.
    Last edited: Mar 22, 2006
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