Relativity and clocks near the earth

  • E. Sappl
  • Published 2005 in Naturwissenschaften


Beginning 20 years ago, since atomic clocks which can be moved over the earth in airplanes, rockets or satellites were available, many experiments were performed to measure relativistic effects on clocks in the vicinity of the earth. These experiments gave 1 070 validitation of predicted effects [1]. An experiment of Vessot et al. with a hydrogen maser in a rocket confirmed the equivalence principle of general relativity at a 2 • 10 .4 level of accuracy [2]. In the Spacelab experiment NAVEX, performed to investigate the possibili ty of navigation by means of satellites during mission D1 in 1985, the relativistic aspects of which we report in this paper , a cesium clock on board the Spacelab was compared with a cesium clock at a ground station by a so-called two-way radio link [3]. The results of this clock comparison are used to compute the predicted relativistic effect, which is in accord with the also directly measured value within an error of 0 . 1 % . Moreover it will be shown that the outcomes of NAVEX are sufficient to validitate the gravitat ional influence on clocks predicted by the general theory of relativity at a level of 1% accuracy. The statements contained in the theory of relativity of clocks are statements about the rates of clocks. The rate of a clock A with respect to a clock B is the slope of the difference (t A tB) of simultaneous readings t A of clock A and tB of clock B, i .e. ,

DOI: 10.1007/BF01138386

Cite this paper

@article{Sappl2005RelativityAC, title={Relativity and clocks near the earth}, author={E. Sappl}, journal={Naturwissenschaften}, year={2005}, volume={77}, pages={325-327} }