Aether Theory and the Principle of Relativity
  This paper completes and comments on some aspects of our previous publications. In ref [1], we have derived a set of space-time transformations referred to as the extended space-time transformations. These transformations, which assume the existence of a preferred aether frame and the variability of the one-way speed of light in the other frames, are compared to the Lorentz-Poincare transformations. We demonstrate that the extended transformations can be converted into a set of equations that have a similar mathematical form to the Lorentz-Poincare transformations, but which differ from them in that they connect reference frames whose co-ordinates are altered by the systematic unavoidable measurement distortions due to length contraction and clock retardation and by the usual synchronization procedures, a fact that the conventional approaches of relativity do not show. As a result, we confirm that the relativity principle is not a fundamental principle of physics [i.e, it does not rigorously apply in the physical world when the true co-ordinates are used]. It is contingent but seems to apply provided that the distorted coordinates are used. The apparent invariance of the speed of light also results from the measurement distortions. The space-time transformations relating experimental data, therefore, conceal hidden variables which deserved to be disclosed for a deeper understanding of physics. 
Joseph Levy