Einstein, Light Signals and the ∈-Decision

Abstract

It is now three-quarters of a century since the publication of Albert Einstein’s ‘On the Electrodynamics of Moving Bodies’. Early in the spring of 1905, when the idea of his work on relativity was “still a mere concept”, Einstein anticipated which part of his work would capture the imagination of his contemporaries. In a letter of March 6th to his friend Conrad Habicht he wrote of “the electrodynamics of moving bodies by the use of a modification of the theory of space and time” and that “the purely kinematic part of this work will undoubtedly interest you”.¹ At the heart of the kinematic part of Einstein’s work lies his discourse on the concept of simultaneity.