In the Optical Effects, the One-Way Synchronization Foresees Transformations Conserving Simultaneity and Spacetime Continuity, Replacing the Two-Way Einstein Synchronization and the Lorentz Transformations, Which Predict Instead a Spacetime Continuity Breach and a Weak Form of the Relativity Principle

Abstract

We revise the optical effects of the Sagnac type where the moving closed contour is covered by a photon in the observable invariant time interval \(T\) . In lieu of the two-way Einstein synchronization, an internal one-way synchronization procedure along the contour can be adopted. For the reciprocal linear Sagnac effect, where the emitter-receiver C* is stationary and the contour is in motion, \(T\) is no longer invariant for the Lorentz transforms, reflecting a weak form of the relativity principle. Instead, the relativity principle is preserved and \(T\) is invariant for transforms based on conservation of simultaneity. In the standard linear Sagnac effect, if the local one-way speed along the optical fiber is assumed to be \(c\), the photon cannot cover the whole closed contour in the interval \(T\). The missing section represents a breach in spacetime continuity related to the "time gap" due to relative simultaneity. Our revision confirms the well-known result that the Lorentz transforms have limited validity and fail in interpreting these effects. The more general validity of transforms based on conservation of simultaneity, disproves Mansouri and Sexl's contended equivalence between relative and absolute simultaneity. The reciprocal linear effect can be used for testing Lorentz and light speed invariance with observable variations of the first order in \(v/c\).