Abstract

The exactness of the experimentally derived Lorentz force equation has seemingly been confirmed by derivations from Minkowski's four-vector force and from Newton's second law of motion. Both types of derivation, however, entail somewhat questionable assumptions. In the first type, there is the rather arbitrary requirement that all laws of nature must be expressed in covariant form; in the second type, it is assumed that the relative velocities of inertial coordinate systems must be mathematically treated as constraints. If, however, this mathematical constancy assumption is replaced by a less abstract view of the physical nature of constant velocities, an amended version of the Lorentz equation is obtained. In this amended version the electric force is found to be identical with that given by the original equation, while the magnetic force only differs by a simple factor that reduces to unity at ordinary velocities. A major difference between the two equations is provided by the presence in the amended version of a third term that may account for the gravitational force.