The Casimir effect in Rydberg states of atoms is an example where a
theoretical prediction stimulated experiment. Spruch and Kelsey in 1978
predicted for the case of an electron and an ion an interaction analogous
to that given by Casimir and Polder for two atoms. In the 1978 paper they
suggested that the effect might be detectable in the Rydberg states of the
helium atom. Shortly thereafter S.R. Lundeen and
collaborators  began an experimental program
to test this suggestion. The interplay between these two groups had some
influence on later theoretical studies of long-range ion-electron
interactions, relativistic phenomena[8,9], Lamb shifts, and high
accuracy variational calculations. The experimental and theoretical
studies continue with, notably, additional experiments carried out by E.A.
Hessels, a former student of Lundeen, and collaborators.
Some of these topics were covered at the ITAMP Topical Group meeting on Casimir Phenomena during the period March 16-27, 1998.
J.F. Babb 2.25.99
More extensive bibliography
 H. B. G. Casimir and D. Polder, Phys. Rev. 73 (1948), 360 (atom-atom and atom-wall); H. B. G. Casimir, Proc. K. Ned. Akad. Wet. 60, (1948) 793 (two walls).
 D. H. Napper and R. J. Hunter in Surface Chemistry and Colloids, M. Kerker ed., (University Park, Baltimore, 1972), vol. 7, ch. 8. See also, for example, P. W. Milonni, The quantum vacuum: An introduction to quantum electrodynamics, (Academic Press, Boston, 1994) for more bibliographic info.
 Fei Luo, Clayton F. Giese, and W. Ronald Gentry, J. Chem. Phys. 104 (1996) 1151; W. Schoellkopf and J. P. Toennies, J. Chem. Phys. 104, (1996) 1155; W. Schoellkopf and J. P. Toennies, Science 266, Nov. 25, 1994, 1345; T. Korona et al. J. Chem. Phys. 106 (1997) 5109.
 C. I. Sukenik, M. G. Boshier, D. Cho, V. Sandoghdar, and E. A. Hinds, Phys. Rev. Lett. 70, (1993) 560.
 S. K. Lamoreaux, Phys. Rev. Lett., 78, 5 (1997); Erratum, ibid., 81, 5475 (1998); M. Bordag, B. Geyer, G. L. Klimchitskaya and V. M. Mostepanenko, Phys. Rev. D, 58, in press (1998).
 E. J. Kelsey and L. Spruch, Phys. Rev. A 18, 15 (1978); ibid. 18, 1055; see also C. K. Au, G. Feinberg, and J. Sucher, Phys. Rev. Lett. v.53 (1984) 1145.
 D. R. Cok and S. R. Lundeen, Phys. Rev. A 23 (1981) 2488; S. L. Palfrey and S. R. Lundeen, Phys. Rev. Lett. 53 (1984) 1141; E. A. Hessels, F. J. Deck, P. W. Arcuni, and S. R. Lundeen, Phys. Rev. A 41 (1990) 3663.
 R. J. Drachman, Phys. Rev. A 26 (1982) 1228; R. J. Drachman, ibid. 31 (1985) 1253.
 E. A. Hessels, Phys. Rev. A 46 (1992) 5389.
 S. P. Goldman and G. W. F. Drake, Phys. Rev. Lett. 68 (1992) 1683.
 G. W. F. Drake , Phys. Rev. Lett. 59 (1987) 1549; G. W. F. Drake, in Atomic, molecular, & optical physics handbook, G. W.F. Drake ed., (American Institute of Physics, Woodbury, NY 1996)
 C.H. Storry, N. E. Rothery, E. A. Hessels, Phys. Rev. A 55 (1995) 967; G. D. Stevens, C. S. Birdsell, and S. R. Lundeen BAPS 43 (1998) 1262.