The most promising area to detect long range forces and the Casimir effect lies in electromagnetic interactions. However, the hope of observing this interaction between a pair of atoms is extremely small. Recent precision experiments on the fine structure of helium Rydberg states has given rise to the hope of observing the Casimir interaction between the highly excited electron and the core atom even though for the states studied experimentally, the Rydberg electron is not quite in the asymptotic region where the Casimer effect manifests itself in a pronounced way. A thorough relativistic quantum field theoretic evaluation of the two photon exchange potential in the electron- ion interaction for all distances beyond a few Bohr radii has been carried out recently, and a variety of corrections comparable to the Casimir effect have been estimated. An accurate verification of the Casimir effect seems to be within reach of both theory and experiment. In this proposal, The principal investigator describes recent progress made and plans to improve on the calculations and extend the investigation to a variety of systems of interest.
