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When does the photon get captured?

  1. Dec 19, 2008 #1
    In undergrad physics I've learned that the hydrogen atom can capture a photon of the correct energy and bump the electron to a higher energy level.

    My question is, how close does the photon have to pass to be captured?

    Does the photon have to hit the electron... ? How does that work? What does it mean to hit a point object?

    Does the photon hit the nucleus? If so then how does the energy get to the electron?
  2. jcsd
  3. Dec 19, 2008 #2


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    Homework Helper

    From the point of view of nonrelativistic quantum mechanics, neither the electron, nor the photon, are really point particles; they are waves that collapse (in the Copenhagen interpretation) spontaneously to certain states under certain conditions. From the point of view of quantum field theory, interactions occur at "blurry" points in space-time (the subtlties of this concept will put you in the renormalization nut house), but even these points are "summed over" (superposition), so there are two blurring effects. At present, we just accept that there is some kind of discontinuity in the condition before and after photon capture. Everett offers an interpretation, the relative state interpretation, that supposedly allows a continuous description of quantum mechanical interaction, but it has been hard for most physicists to swallow. Unfortunately, modern physics will not satisfy your question, and you can go mad trying to understand the answers that it does offer.
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