Introduction

Maxwell’s electrodynamics when applied to moving bodies, leads to asymmetries which are not inherent in the phenomena.

An example is the reciprocal electrodynamic action of a magnet and a conductor.

This depends only on the relative motion of the conductor and the magnet.

When the magnet is in motion and the conductor at rest, an electric field is created in the neighbourhood of the magnet with a certain definite energy.

This produces a current at the places where parts of the conductor are situated.

But if the magnet is stationary and the conductor in motion, no electric field arises in the neighbourhood of the magnet.

The conductor has an electromotive force that leads to electric currents of the same path and intensity as those produced by the electric forces in the former case.

This, together with the failure to detect any relative motion of the Earth to the Fresnel aether, suggest that electrodynamics and mechanics are constantly moving.

They suggest a “Principle of Relativity”.

This is made up of 2 postulates:

1. The same laws of electrodynamics and optics are valid for all frames of reference where mechanics are valid.
2. Light is always propagated in empty space with a definite velocity c which is independent of the state of motion of the emitting body.

We will raise this conjecture (the purport of which will hereafter be called the ) to the status of a postulate, and also introduce another postulate, which is only apparently irreconcilable with the former, namely, that

These 2 postulates lead to a simple and consistent theory of the electrodynamics of moving bodies based on Maxwell’s theory for stationary bodies.

The “luminiferous ether” is superfluous since there is:

• no “absolutely stationary space” that has special properties
• no velocity-vector for each point of the empty space where electromagnetic processes happen*

Like all electrodynamics, my theory is based on the kinematics of the rigid body.

This is because it deals with the relationships between:

• rigid bodies (systems of co-ordinates)
• clocks
• electromagnetic processes