The One-Way Light Speed Is Measurable: Nonequivalence of the Lorentz Transformations and the Transformations Preserving 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 in interpreting 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 cannot cover the whole closed contour in the measured interval \(T\). Thus, the LTs imply a breach in spacetime continuity related to the "time gap" due to relative simultaneity. Our results invalidate Mansouri and Sexl’s conventionalism of the speed of light and the contended equivalence between relative and absolute simultaneity[1].