I'm reading Feynman's book QED, and while I'll need at least another couple of read-throughs to grasp what I can, there are already a few fundamental questions I have. Feynman explains that electrons and protons within an atom exchange photons (p. 113 of my copy). I'm interpreting this as the photon is used to transmit the electrical force between protons and electrons, and thus it is what keeps the electron attracted to the nucleus. Is this basic idea correct? If so, how do photons exert the electrical force? I've seen Feynman diagrams of electron-electron interactions using photons, and in these diagrams the electrons repulse each other via what appears to be the conservation of momentum in emitting/absorbing photons. In other words, e1 emits a photon towards e2, and in doing so, will change direction to away from e2 to conserve momentum from emitting the photon. e2 does a similar thing upon absorbing the photon, and thus the two particles have repulsed each other. Is this the mechanism of electrical force, carried out by photons, or am I reading too much into this? If so, how does this picture change with a proton and electron such that the force is attractive? Furthermore, even if this is explained, it leads to the issue of when photons are emitted. I was under the impression that electrons in high-energy states randomly emit photons, and return to lower-energy states. If photon exchange is fundamental to proton-electron attraction, it would seem that much more regular exchange of photons would be necessary, even if the electron is already in the lowest energy state -- and thus, how can it emit a photon towards the proton? And what if the photon "misses" the proton? How is that energy recovered/regained? Is it the case that in some circumstances particles "shoot" photons at other nearby particles, and this is different from an excited electron randomly emitting radiation? Explanations, or a pointer to something that explains this to a physics newbie are much appreciated!