joeblow As I mentioned before, there is no recoil force on plate 1 because the "electric bullet" has no mass. Correct, the ‘electric bullet’ has no mass. But it has relativistic properties of mass like momentum and kinetic energy, which is dependent on the frequency of the “electric bullet.” The magnitude of such a ‘bullet’ fired from plate 1 would need to be large enough to have an effect on plate 2, right? But that is only a minor problem. I mentioned before that all you might manage to produce is vibrations at best. If plates 1 and 2 are connected together, all forces if any, will cancel out and the plate assembly will simply vibrate. If they are not connected and you manage to move plate 2 with the force of an ‘electric bullet,’ again the forces if any, will cancel out at the mechanism supporting the plate assembly and that of the ship. Again, vibrations at best.