When calculating the lowest order self energy corrections for an electron for example, feynman diagrams involving the emission and re-absorption of a (virtual) photon need to be considered, (as here for example: http://quantummechanics.ucsd.edu/ph130a/130_notes/node475.html )
but how is it possible for the emitted photon to be re-absorbed by the same electron? why hasn't the photon immediately raced away into the distance leaving the electron far behind before it can be re-absorbed? is this just a case of not taking these diagrams too literally?
Edit: After the electron emits the photon, both the particles should be considered as free particles and hence they cannot meet again unless the photon collides with some other particle and races back to be absorbed by the source electron. In other words, we need atleast a third vertex in the Feynman diagram for it to be possible for an electron to emit and absorb the same photon.
So, how can such a process be possible with just two vertex?