Motional Consequences

Abstract

The electromagnetic interaction is assumed to take place by an exchange of momentum mediated at a finite speed. The origin of magnetic and inductive forces as motional consequences is then clarified. Alternatively, knowing electric and magnetic forces, the speed of light is obtained. From the force between like charges in parallel motion, the Einstein principle of relative motion is formulated. Defining time as a measure of motion, time dilation is derived. The force between like charges in anti-parallel motion together with the principle of relative motion are used to define relativistic momentum. Special relativity is then developed. The relativistic kinetic energy and the energy mass equivalence are derived. Lorentz transformations and the concept of four-vectors are developed in the exercise section.

I have long held an opinion, almost amounting to conviction, in common I believe with many other lovers of natural knowledge, that the various forms under which the forces of matter are made manifest have one common origin; or, in other words, are so directly related and mutually dependent, that they are convertible, as it were, one into another, and possess equivalents of power in their action.

Michael Faraday, 1845