钟速同步的传递性等价于热力学第零定律

平直或弯曲时空中的平衡热辐射，表现出用坐标量表示的普朗克黑体谱.把热平衡系统的辐射具有普朗克黑体谱作为一条基本的物理规律，以此为基础，论证钟速同步的传递性等价于热力学第零定律.钟速同步的条件比建立同时面的条件要弱.满足这一条件的时空，热力学第零定律在其中成立.第零定律成立的时空，一定可以定义统一的钟速.关键词：

TRANSITIVITY OF CLOCK RATE SYNCHRONIZATION BEING EQUIVALENT TO THE ZEROTH LAW OF THERMODYNAMICS

The equilibrium thermal radiation in a flat space-time or a curved space-time behaves like Planck black spectrum represented with coordinate quantities.We regard the fact that the radiation from a thermal equilibrium system shows Planck black spectrum as a basic physics law,from which it is demonstrated that the transitivity of clock rate synchronization is equivalent to the zeroth law of thermodynamics.The condition of clock rate synchronization is weaker than that constructing simultaneity surfaces.In the space-time satisfying the condition of clock rate synchronization,the zeroth law of thermodynamics is valid.On the other hand,in the space-time where the zeroth law is valid,one can define an identical clock rate.