爱因斯坦等效原理是广义相对论的基石,引力场的钟慢效应和引力红移效应是等效原理的两个基本推论;双生子问题属于狭义相对论的范畴.等效原理与双生子问题间的联系在相对论的教学中常被忽视.文章基于爱因斯坦等效原理,将匀加速系统与一个均匀引力场等效起来,详细地推导出引力场的钟慢效应,并证明了与之本质相同的引力红移效应;最后根据等效原理的这些基本推论在广义相对论框架下讨论了双生子问题,并用一个清晰的物理图像给出了双生子问题的广义相对论解释.
Einstein's equivalence principle is the cornerstone of general relativity. The time di- lation effect of gravitational field and gravitational redshift effect are two fundamental infer- ences of the equivalence principle. Twin paradox is a basic question detailed-discussed in the context of special relativity. The correlation between equivalence principle and twin paradox has been frequently overlooked in teaching of the relativity. In this paper, based on Einstein's equivalence principle, we equaled a uniform acceleration system to a uniform gravitational field. The time dilation effect of gravitational field was deduced in detail, and the gravitational redshift effect was proved to be intrinsically identical to it. According to those fundamental inferences, we finally discussed the twin paradox and provided an explicit physical diagram to explain this elusive problem in the context of General Relativity.