Textbook in PDF format Relativity can seem violently counterintuitive. It says that different observers can describe the world in very different ways and they can all be correct. It helps to be reminded that you've known this since childhood, when you learned that the direction you call left might be the same as the direction I call right, and we can both be correct. This book illuminates and demystifies the theory of relativity through repeated analogies to that kind of everyday experience. Dozens of drawings, analogous to the maps we all use to navigate through ordinary space, emphasize that relativity is a branch of geometry — the geometry of navigating through that more mysterious venue called spacetime