This website describes an alternative approach to the Theory of Relativity, which is based on the use of Newtonian mechanics with variable mass.

The constancy of the speed of light is not postulated, and the Lorentz transformation is not used for the derivation of the relativistic equations.

Before proceeding, we recommend that you read the “Notice to the reader”.

Two important findings

The start of this alternative approach is based on two important findings.

Max Born reports on the first finding. In his book “Einstein’s Theory of Relativity” he shows that there is a “simple proof of Einstein” for the equation E=mc², which “does not make use of the mathematical formalism of the theory of relativity”.

Richard Feynman mentions the second finding in his work “Lectures on Physics“. He points out that the Second Law of Motion is applicable with the relativistic mass formula.

Since the Second Law of Motion with constant mass describes classical mechanics, the question arises: what can then be achieved with the same law, assuming a variable mass?

Newton’s law in connection with E=mc² leads to relativity

Well, it turns out that Newton’s law, in conjunction with the energy-mass equivalence E=mc² derived from classical physics, can introduce the theory of relativity in a simple and intuitive way.

This path was consistently pursued in the book “Newton and Relativity” with amazing results:

Starting from the Second Law of Motion with variable mass, all relevant equations of the special theory of relativity up to the constancy of the speed of light can be proven by a sequence of comprehensible derivations.

Newton’s law is generally valid

It is shown that the Second Law of Motion remains generally valid even under relativistic conditions, and that it thus enables a direct transition from Newtonian to relativistic mechanics.

That is essentially the approach taken here.

The aim is to offer a simple introduction to the Special Theory of Relativity in which the most difficult concepts are avoided at the beginning.

Concepts such as “length contraction“, “time dilation“, “Lorentz transformation” and, finally, the “constancy of the speed of light” are not the prerequisites but the objective of this alternative approach to the theory of relativity.

We recommend that you click on the "Sequence of Relativistic Proofs" to continue reading.