Electric field lines from a moving charged particle

[nomadreid]

The electric field emanating from charged particle travels at the speed of light; fine. To pose an unrealistic thought experiment (a more realistic, if more complicated, thought experiment could replace this one, but the unrealistic one gives the idea), if a proton were to suddenly pop into existence at a certain time T in a vacuum, and a stationary electron were situated 300,000 km away (and nothing else in the vicinity), then after one second, at time T+1 (ignoring the difficulty in synchronizing watches ), the electron would start to move towards the proton (and vice-versa, of course) in a straight line between the electron and proton. So far, so classic. However, if that proton is moving, would the electron at the moment T+1
(a) start to move toward the position the proton was at time T, or
(b) with a sort of quantum-eraser retroactive effect move toward the position the proton would be at time T+1?
(ignoring the effect of any magnetic field created by the moving proton)
Thanks in advance.

 

[mfb]

The appearing proton violates the laws of electrodynamics (charge conservation). It does not make sense to ask what physical laws predict in a situation where the laws are violated.

"Where the proton was one second ago" is a better description, but it is not always exact.

 

[nomadreid]

Thanks for the reply, mfb.

The appearing proton violates the laws of electrodynamics (charge conservation). It does not make sense to ask what physical laws predict in a situation where the laws are violated.

This is why I inserted the caveat that one could certainly make up a Gedankenexperiment which did not violate the laws of physics but which got the idea across. My experiment was in the spirit of 3:40-5:20 of Greene's . I could have perhaps better simply asked the question without thought experiment in this way: "assuming it makes sense to talk about the velocity and straight-line path of the carriers of the electric field, then it makes sense to ask about that path as a straight line between two space-time points. Are these points separated in time as would be expected in a classical theory, or not?"

"Where the proton was one second ago" is a better description, but it is not always exact.

I presume that is the answer to my question, despite its impossibility. I also presume that the lack of exactitude you refer to is due to relativistic considerations, not to mention the magnetic field. Any further corrections will be appreciated.
Thanks again.