On the Problem of Relativity

InAbraham, M. an article entitled The new mechanics, which recently appeared in this journal, I discussed from a historical and critical point of view the two theories of relativity established by Einstein in 1905 and 1913. Since then, the author himself has expounded his views in a very useful article on the psychology of relativity, without, however, refuting the serious objections I had raised against both the “restricted” theory of 1905 and the “general” theory of 1913.