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Special relativity is a standard topic in the undergraduate physics curriculum, appearing in the Modern Physics course during the second year of the program. This topic is usually covered in the first few classes of the course, following a conventional approach of using Lorentz transformations presented in the beginning chapters of all Modern Physics textbooks. Some years ago, it had been recommended to me to consider using a volume from Thomas Moore’s collection Six Ideas That Shaped Physics – the relevant volume was Unit R: The Laws of Physics are Frame-Independent. Moore's presentation relies on the introduction of spacetime diagrams, which provide a powerful graphical method of attacking problems as an alternative to equation-driven Lorentz transformations. Using spacetime diagrams, solutions to relativity problems are more concise, visually comprehensible, and much more intuitive, which is quite a feat for one of the more counter-intuitive topics in physics.
The textbook has 9 chapters, with 6 chapters on relativistic kinematics and 3 chapters on dynamics. Each chapter is length-contracted to be only 12-15 pages, which is a digestible amount of material for one class period. The material can be thoroughly covered in 8 class periods, which is probably longer than most Modern Physics courses allocate; however, with such an in-depth treatment, the rewards for the students are significant. Students learn to draw and interpret worldlines in spacetime diagrams, to exploit the spacetime interval as a frame-independent quantity, to draw two-observer diagrams, and to analyze paradoxes in the context of the graphical approach. For dynamics, students are introduced to four-vectors (four-momentum) and are trained to utilize conservation of four-momentum to analyze particle collisions and particle production reactions. As a nuclear physicist myself, I have found this formulation of relativistic dynamics to be surprisingly simple and enlightening, and the students are readily able to grasp the concepts and handle the calculations.
