Hi, I'm learning special relativity with the book Introduction to Special Relativity by R. Resnick, but unfortunately he doesn't provide answers to the questions (not problems). So I would like to aks you if you could correct some of my answers. 1. The problem statement, all variables and given/known data 1. Can a particle move through a medium at a speed greater than the speed of light? 7. Discuss the following comment, which applies to most of the figures: "The figure itself belongs to some particular reference frame, that is, the picture represents measurements made in some particular frame." Can we look omnipotently at moving frames, wave fronts, and the like, with-out realizing first what frame we are in? 10. Does the Lorentz-Fitzgerald contraction hypothesis contradict the classical notion of rigid body? 3. The attempt at a solution 1. I don't see any reason why it couldn't. The speed limit is the speed of light in vacuum and so theoreticaly some particle can travel faster than the speed of light in that medium. (I'm definitely not sure if it is possible practically...?) 7. I don't really understand what "omnipotently" means (English is not my native language) and generally I don't really understand the question. I would say we firstly have to measure the speed relative to the moving frame and thus realize what frame we are in (relatively to the moving frame). So the answer is we can't. 10. I think it does. Simply because the length of an object is dependant upon its velocity. That is in cotradiction with the notion of a rigid body. Thank you very much for your help.