  The recent development of a scanning thermal microscope (SThM) has led to
measurements of radiative heat transfer between a heated sensor and a cooled
sample down to the nanometer range. This allows for comparision of the known
theoretical description of radiative heat transfer, which is based on
fluctuating electrodynamics, with experiment. The theory itself is a
macroscopic theory, which can be expected to break down at distances much
smaller than 10-8m. Against this background it seems to be reasonable to
revisit the known macroscopic theory of fluctuating electrodynamics and of
radiative heat transfer.
