Sign inversion for the velocity of light — A new discrete symmetry transform in electrodynamics

The invariance of the electrodynamic equations with respect to change in sign of the velocity of light is shown. Some physical consequences of this symmetry are considered.I. V. Kurchatov Institute of Atomic Energy. Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 12, pp. 69–72, December, 1992.