• Ook the Librarian@lemmy.world
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    1 year ago

    Since photons are indistinguishable, it’s hard to say too much concretely, but it some sense a diffracted photon is different photon. In order for a photon to interact with say, a diffraction grating, the interaction is done with “virtual photons”.

    So for a photon to change course, aka accelerate, it does it by absorbing a virtual photon and emitting another. Whether that is the “same photon” after the interaction is kinda more philosophy than physics, at least to me.

    Feynman diagrams are surprisingly accessible for how much information they contain. It’s one way to think about photon (and other particle) reactions.

    • ziggurism@lemmy.world
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      1 year ago

      There is no tree level photon-photon interaction. Photons scatter off electrons (or any other charged particle), not off neutral photons.

        • ziggurism@lemmy.world
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          1 year ago

          The electromagnetic field does have a force carrier. It is the photon.

          The photon mediates the force between electrically charged particles. It cannot mediate any reaction between two neutral photons.

          • Ook the Librarian@lemmy.world
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            1 year ago

            Ah, I see. Sorry for the snark. I was thinking more in line with the Compton effect, and thought you were talking about something like that too. (Even though it’s clear that you were explicitly not. I thought you were denying photon-virtual photon interaction because I was talking about it in a funny way.)

            I would still say it’s still philosophical whether photons experience acceleration, but I concede that photon-photon interaction is not done by virtual photon exchange.