The potential energy and electric field?

Where does a dipole's electric potential energy go when it aligns with a field?

• Just doing some first year physics for exams, and thought about something I don't understand. A simple dipole in an electric field has a calculable potential energy = -p.E.cos(phi) Where p = the electric dipole moment, E = magnitude of electric field, phi = angle between axis of dipole and electric field. So when an electric field is applied to a dipole, we are of course taught that the particle will align itself with the field, minimising potential energy. Where does this energy go? Some must be transformed into kinetic energy for the dipole to rotate, but then what? Does it oscillate around an equilibrium parallel to the field? I can't really think of any explanation which justifies the dipole becoming stationary. I'm probably just thinking wrong :) but cheers for the help guys.

• Answer:

  No, you're thinking correctly. The dipole will oscillate, but in doing so will emit electromagnetic radiation (since accelerating charges radiate). The potential energy will therefore mainly become light waves.