Rotating frames in special relativity analyzed in light of a recent article by M. Strauss

The argument of Einstein for non-Euclidity on a rotating disk is analyzed and found valid. The kinematic reason for the non-Euclidean geometry is stated explicitly and provides a kinematic resolution of Ehrenfest's paradox. The transformation from an inertial frameK to a rotating frame, the axis of which is at rest inK, is discussed. It is concluded in favor of the Galilean-like transformation employed by Møller. The method used by Møller in obtaining the intrinsic spatial geometry in any frame is examined. It is found to be adequate, provided that only coordinates with a proper metrical significance are used. In this connection the distinction between global and local geometry is found to be essential.