  We consider two perfectly smooth featureless surfaces at T=0, defined only by
their respective dielectric functions, separated by a finite distance, and ask
the question whether they can experience any friction when sheared parallel to
their interface. We find large frictional effects comparable to everyday
frictional forces provided that the materials have resistivities of the order
of 1 m-Ohm and that the surfaces are in close proximity. The friction depends
solely on the reflection coefficients of the surfaces to electromagnetic waves
and its detailed behaviour with shear velocity and separation is dictated by
the dispersion of the reflectivity with frequency.
