  When light is passing through a rotating medium the optical polarisation is
rotated. Recently it has been reasoned that this rotation applies also to the
transmitted image (Padgett et al. 2006). We examine these two phenomena by
extending an analysis of Player (1976) to general electromagnetic fields. We
find that in this more general case the wave equation inside the rotating
medium has to be amended by a term which is connected to the orbital angular
momentum of the light. We show that optical spin and orbital angular momentum
account respectively for the rotation of the polarisation and the rotation of
the transmitted image.
