A space-time ruler-based explanation of relativistic effects

The concepts of a time ruler and space ruler are put forward, where the zoom of the space-time ruler provides for an intuitive explanation of the time dilation and length contraction effects associated with theory of relativity. Mass and energy can be regarded as measurements of matter by the time ruler, while momentum can be regarded as a measurement of matter by the space ruler. The space-time ruler can be divided into two kinds according to the causes of its deformation: a relative motion space-time ruler and a gravitational field space-time ruler. It is proved that there is equivalence between these two kinds of rulers under weak field conditions, with this amounting to another expression of the equivalence principle in general relativity. It is pointed out that the two kinds of space-time ruler can be superposed, with the formula for calculating the clock difference between satellites and ground stations being given by this superposition. A GPS satellite is used as an example to calculate clock difference in this way, and the calculation results are in agreement with the classical formula.