Revisiting the electric potential

Vavagiakis, Bachlechner, and Kleban reply: Fritz Bopp correctly points out that creating a potential difference necessitates a nonzero electric field. He goes on to assert that the field must cross the particles’ paths, differentially accelerating them. If that were the case, the difference in phase could indeed be explained by the interaction of the particles with the electric field. As we describe in our Quick Study, however, the field could be switched on for a while and then off again while the particles are deep inside two long, tubular Faraday cages. Those cages shield the particles from contact with the nonzero field, yet while the field is on, there is a potential difference between the interiors of the two cages. That potential difference is therefore responsible for the difference in phase.