To write a book to explain in simple, non-mathematical terms what superstring theory is is not a simple task. In The Elegant Universe Brian Greene, a physicist who works in the area, does a very good job. Superstrings are a theory of particle physics that lays claim to being the ultimate "Theory of Everything", merging Einstein's relativity and quantum mechanics into an understanding of the physics of the very small and very large in the Universe. Hence to understand superstrings relativity, quantum mechanics have to be explained as well. In this Brian Greene does a very good job, giving one of the best explanations of relativity I have read in the process. Superstring theory is still very much in its infancy and The Elegant Universe does not claim that all the problems have been solved, in fact a point is made of pointing out all the present deficiencies of the theory.

Probably not a book for the very beginner but anyone who has read popular accounts of particle physics and relativity should gain a lot from reading this book. In places not an easy read, not for style reasons(which was generally very easy) but simply for the difficulty of some of the concepts involved. Superstring theory may or may not be the theory of everything but this book will certainly tell you what we think we know so far. Definitely recommended but don't expect to read it in a weekend. —Simon Goodwin