Abstract

Frank Jackson and Robert Pargetter propose a method for synchronizing clocks at rest at distant points of an inertial system in Euclidean space, which, they claim, does not depend on Einstein's signalling method and provides a basis for denying the conventionality of distant simultaneity. I am afraid, however, that the new method presupposes that the simultaneity of distant events relatively to the chosen inertial system has been already determined by Einstein's or some other method. Jackson and Pargetter describe their method as follows: Let UA, UB be clocks at A, B, respectively. Let XY be an axis perpendicular to AB, passing through C, the midpoint of AB. Take a rigid straight rod A′B′ with midpoint C′ and length equal to the length AB. Move A′B′ with uniform velocity such that C′ travels along XY towards C, and A′B′ is perpendicular to XY ; then if the reading … on UA just when A′ coincides with A is the same as the reading … on UB just when B′ coincides with B, clocks UA and UB will be synchronous..