Wolfgang Pauli was a brilliant theoretical physicist responsible for positing the Pauli Exclusion Principle and the winner of the 1945 Nobel Prize in Physics. However, at the first printing of this book, Pauli was a young man of 21. I really admire that sort of thing, to be able to publish something like this at that age. The book acknowledges that there are issues with its contents since it was printed in 1921, but this book does a fine job of showing off relativity as it was known at that time.

Theory of Relativity is split into five major parts. They are as follows.

In part I, Pauli begins by defining the History of the Special Theory of Relativity. You know, the one that states that the speed of light is constant in all reference frames and that the laws of physics are the same for all inertial systems. This section of the book also discusses the consequences of that idea, the Lorentz Contraction and time dilation. Although this part of the book does have some equations that use curl and div, not many of them are shown.

With part II, we are introduced to some mathematical tools to help us on our journey to understand relativity. This section introduces the idea of "space-time," a four-dimensional manifold that is our reality. So Pauli starts to talk about transformation groups and using tensor calculus for affine transformations. Pauli demonstrates the basic ideas of tensor algebra and how to use them to anticipate the final results we are trying to find and the ideas of Riemannian Geometry to account for space-time curvature.

Part III elaborates on the Special theory a little bit more, taking care to discuss Kinematics, Electrodynamics Mechanics, and Thermodynamics in a relativistic manner.

Part IV discusses the General Theory in all its glory.

Part V is called Theories on the Nature of Charged Elementary Particles.

In total, Theory of Relativity contains 499 equations, some of them with those old-timey German Script letters that I believe to relate to a field. It also contains a ton of notes which are further discussed at the end of the book. ( )