The One-Way Light Speed May be Measurable: Non-Equivalence of the Lorentz Transformations and Transformations that Preserve Simultaneity and Spacetime Continuity

Based on our analysis of the GPS and other physical effects, we confirm the well-known view that the Lorentz transformations (LT) fail to interpret light propagation along a closed moving contour. We show in detail that, with the LT based on light speed invariance, in the standard linear Sagnac effect a photon traveling at the local speed c cannot cover the whole closed contour in the measured interval T. Thus, the LTs imply a breach in spacetime continuity related to the adoption of relative simultaneity. Making use of internal synchronization procedures a priori not equivalent to Einstein synchronization, in principle it is possible to test Lorentz and light speed invariance and confirm, or not, the contended equivalence between relative and absolute simultaneity.