ON THE SPEED OF LIGHTS

Abstract

The aim of this paper was to explore the curious change of opinion about the speed of light that occurred around the end of the nineteenth century. Till then light was judged to move according to the general laws of material motions as classically described by Oresme, Galileo and Newton -  it accelerated and retarded with its source or observer. Michelson's experiments as interpreted by FitzCerald and Lorentz then lead to the currently held notion that the speed of light was a universal constant, it did not change by the speed of its source or observer. At the same time, recent books on physics [1],[ 2] while extolling the Theory of Relativity with its speed of light c², didn't mention Michelson at all. Meticulous examination of primary sources cast doubt on the validity of this generally accepted universal constant.