空间引力红移实验的原理与精度

通过对文献4, 5]关于空间引力红移实验原理与精度的分析,根据爱因斯坦惯性力与引力等效的原理,提出在航天器内部,重力的大部分被惯性力抵消,因而其中的微重力比轨道重力小很多(失重).因此,应当把星载原子钟的重力势取为与微重力相当的有效重力势,而不能简单地将星载钟的重力势取为轨道重力势.另外,检验相对论红移需要将理论值与实验值进行对比,这两种数值均具有误差,而检验精度取决于误差较大者.因此,如果不提高地球重力模型(例如EGM2008)精度而只提高测量精度则不能提高检验精度.

Principle and Accuracy Problems of Gravitational Redshift Experiments in Space

In this paper, the problems about the principle and accuracy in the experiments of space gravitational redshift are analyzed. Firstly, according to Einstein Equivalent Principle (inertial force is equivalent to gravity), the main part of Earth's gravity inside the spacecraft is cancelled out by inertial force, so that the microgravity inside the spacecraft is much smaller than the gravity at its orbit. For this reason, the gravitational potential of the space borne clock should be taken as an effective gravitational potential corresponding to the microgravity. However, in Ref.4] (GP-A experiment) and Ref.5] (Radio astron satellite program), the gravitational potential of the clock is simply taken as the gravitational potential at the orbit. Secondly, testing the relativistic redshift requires a comparison between theoretical prediction and experimental measurement. The accuracy of this test is determined by the larger error. Therefore, if improving just the experimental precision but not the accuracy of the Earth Gravitational Model, then the test accuracy cannot be improved.