On a Heuristic Point of View about Newton's Laws, Mach's Principle and the Theory of Relativity

It will be shown that Newton’s theory already implies a maximum velocity with which a massive particle can travel if the universe is included into the consideration (according to Mach’s principle). The resulting formulas for the velocity dependence of the particle’s mass and it’s energy are identical with those of SR. The constancy of the speed of light does not have to be postulated for this purpose, but comes rather as one of the results. The results suggest also that the speed of light (in “vacuum”) is not a natural constant. One can also conclude that the “action at a distance” – property of Newton’s law of gravity is not in contradiction to the local character of nature as described by the theory of relativity.