Semi-Classical Electrodynamics and the Casimir Effect

From the late 1960s onwards, the groups of Barry Ninham and Adrian Parsegian, and their many collaborators, made a number of essential contributions to theory and experiment of intermolecular forces. In particular, they explored the semi-classical theory: Maxwell’s equations and Planck quantization of light leads to Lifshitz and Casimir interactions. We discuss some selected thought-provoking results from Ninham and his group. Some of the results have been conceived as controversial but, we would say, never uninteresting.