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Photon's charge

  1. Jul 27, 2007 #1
    recently, I read a news that stated that photons, or light particle, has a small amount of charge. what does this suppose to means, and how we know, and how come?
  2. jcsd
  3. Jul 27, 2007 #2


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    This is a serious misunderstanding. The charge of the photon is still supposed to be 0, but it is not possible to determine it to 0 with 100% accuracy experimentally.

    So a recent experiment has shown, that the upper bound for the photon charge is somewhere around 10^{-46} times the charge of an electron. Before the experimental upper bound was somewhere around 10^{-33} times the charge of an electron.
    This does not mean, that a photon is charged. We just got closer to 0.

    You certainly mean this article:
    Bound on the Photon Charge from the Phase Coherence of Extragalactic Radiation by Brett Altschul
    Phys. Rev. Lett. 98, 261801 (2007)
  4. Jul 27, 2007 #3

    Hans de Vries

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    Where did you read that?

    Photons do not have charge, otherwise we would be able bend light with an
    electric field. Also, charge is quantized. It does not come in arbitrary small

    The photon has two big brothers which do have a positive and negative
    charge equal to that of the electron. These are the intermediate vector
    bosons W+ and W- which propagate only over extremely small ranges,
    smaller as the radius of an atom's nucleus.

    Regards, Hans
  5. Jul 27, 2007 #4


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    Again, as has been repeated many times, such a "reference" is not sufficient to conduct any sense of a rational discussion. You must cite a proper reference. It is no longer sufficient here on PF to simply use "I heard" or "I read" when trying to discuss something in this context.

    So this is a reminder to everyone else, especially new members on here. If you cannot provide a sufficiently clear source that you can cite, then it can't be that important to you for you not to jot it down, and it can't be discuss with any sense of clarity on here.

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