Reflection of light from a uniformly moving mirror

Abstract: We developed a formula for the law of reflection of a plane-polarized light beam from an inclined flat mirror in uniform rectilinear motion by a direct application of the Huygens-Fresnel principle. Applying the obtained formula and the postulates of special relativity to describe a specific thought experiment, we showed that the moving mirror must be contracted along the direction of its motion by the usual Lorentz factor. The result emphasizes the reality of Lorentz contraction by showing that the contraction is a direct consequence of the first and second postulates of special relativity, and not a product of the process of relativistic measurement of the length.