Published online by Cambridge University Press: 28 February 2022
By a kinematical theory we mean a theory of space, time, and light signals as measured by rigid rods and clocks. In this paper we shall construct an axiomatization of possible kinematical theories which has two especially interesting properties: it is universal in the sense that it presents a threefold continuum of kinematical theories ranging from Special Relativity (STR) on one extreme to Classical Aether Theory on the other; and it is synchronization independent, that is, it does not assume any particular synchronization for clocks. Reichenbach's axiomatization has the threefold continuum implicitly in it, but he does not explicitly present it as a universal axiomatization and he does not give it a synchrony free formulation. On the other hand, the synchrony free axiomatization of STR by Winnie is not universal and it masks an important distinction within the light principle. However, both of these axiomatizations were central to developing the present axiomatization.