Special Relativity and the Lorentz Transformations

According to the principle of relativity , the laws of physics, including the laws of relativistic mechanics and of optics, electromagnetism and nuclear physics, are the same in all inertial reference frames . Similarly, the Lorentz transformations are the appropriate transformations if the laws of electromagnetism are to obey the principle of relativity. However, the Lorentz transformations do necessitate a revision of the concepts of absolute space and absolute time, and this aspect of the Lorentz transformations is best developed by taking as our second postulate the principle of the constancy of the speed of light. This chapter describes how one inertial observer with a radar set can determine the positions and times of distant events. Using radar methods, Mary measures the time interval between the two ticks on John&s;s clock to be γ times what he does. Thus, using radar methods, Mary measures John&s;s clock to go at a slower rate than her own clock.