  The brachistochrone problem can be solved either by variational calculus or
by a skillful application of the Snellius' law of refraction. This suggests the
question whether also other variational problems can be solved by an analogue
of the refraction law. In this paper we investigate the physically interesting
case of free fall in General Relativity that can be formulated as a variational
problem w. r. t. proper time. We state and discuss the corresponding refraction
law for a special class of spacetime metrics including the Schwarzschild
metric.
