• Maximal acceleration;
  • accelerated systems;
  • clock hypothesis;
  • time dilation: Doppler shift due to acceleration.


Based on the generalized principle of relativity and the ensuing symmetry, it has been shown that if the Clock Hypothesis is not true, there is a universal maximal acceleration am. We present here an extension of relativistic dynamics for which all admissible solutions will have have a speed bounded by the speed of light c and the acceleration bounded by am. An additional Doppler type shift for an accelerated source is predicted. The formulas for such shift are the same as for the usual Doppler shift with v/c replaced by a/am. The W. Kündig experiment of measurement of the transverse Doppler shift in an accelerated system was also exposed to a longtitudal shift due to the acceleration. This experiment, as reanalyzed by Kholmetskii et al., shows that the Clock Hypothesis is not valid. Based on the results of this experiment, we predict that the value of the maximal acceleration am is of the order 1019m/s2. Moreover, our analysis provides a way to measure experimentally the maximal acceleration with existing technology.