An Aid for Clarifying Space-Time Concepts in Special Relativity

It is shown how a diagram of two different inertial reference frames, representing the situation at a given instant from the viewpoint of one of the frames, can be used to develop insight into the various space-time effects of special relativity. An analysis is given of a number of thought experiments in which each frame makes its own measurements of various properties and then watches the other frame make similar measurements, Each frame can then interpret the data of the other frame. Measurements of relative speed, speed of light, Lorentz contraction, and time dilation are discussed in this way. Also, the same approach is used to consider causal difficulties arising from the possible existence of faster-than-light particles (tachyons).