(February 9, 2016 at 6:17 pm)Alex K Wrote: Finding intuitions behind these processes described by Feynman graphs is a difficult, but interesting exercise.
I'm not sure the photon needs to know beforehand that there is another electron. Electrons are surrounded by a cloud of virtual photons which they give off and absorb all the time even when they are alone (as indicated by self-energy diagrams). If there is another electron in the vicinity, they can be absorbed by that one from time to time. At least that's my half baked explanation.
I did not know about the 'photon cloud' you described. That would begin to explain how the particles interact, but I can still just zoom in unless there's a continuous and completely filled space. Plus, electric and magnetic fields are quite large when we get enough piled together. We're talking about macroscopic lengths coming from stacks of electrons.
I don't think there is a good answer to this, but it is fun to think about.
Meandering Atheist: Several friends on a journey of romance and adventure, to talk about moderately interesting topics.
