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Does Photons bouce off eachother

  1. Sep 5, 2007 #1
    Does a photon bounce off another photon. Say you had hundreds of watts of laser photons shooting in one direction. Then in the other direction a few stray photons. Will they get deflected off to the side or backwards? If so, then it would explain why the double slit experiment would work. That the photons are constantly bumping into eachother and going seperate ways. That is unless they are not deflected in the up and down axis though.
  2. jcsd
  3. Sep 5, 2007 #2
    The interaction of visible spectrum photons is predicted in QED. However, it is a very weak 4-th order effect, which has not been observed yet, as far as I know. Even if this interaction was strong, it could not be used to explain the double-slit experiment, because the interference pattern exists even when photons are released one-by-one, and do not have a chance to interact with each other.

  4. Sep 5, 2007 #3
    Ok, so I've tried several times already, but can't seem to figure out what QED stands for. I'd guess the Q is quantum, but that's as far as I get. Can someone help me please? Thanks.

    Besides that the double-slit works with individual photons at a time, I don't see how this collision effect could play a large role. It simply doesn't seem to create or imply an interference pattern (wave interference), at least as far as I can see.

    A possibly interesting point is this then: a photon bouncing off another should count as detection, right? So if the photons were hitting a lot, wouldn't they seemingly lose their wave-like properties, and thus not form as strong an interference pattern if many photons were shot simultaneously?
  5. Sep 5, 2007 #4
    QED = quantum electrodynamics

  6. Sep 6, 2007 #5
    I select the word in the text, right-click, and choose "Search Dictionary for QED..." and that opens this page in another tab.

    Very handy for all my reading! Paper just cannot compare.
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