As with Stephen Hawking’s book *A Brief History of Time*, the title of this book suggests that it is for non-specialists or readers with minimal scientific background. Early on, this impression is reinforced by the author’s use of everyday analogies as a means of conveying profound ideas from physics and quantum theory. But, like Hawking’s book, the layman proceeds only so far before being overwhelmed by the essential complexities of particle physics, quantum theory and quantum gravity..

The difficulties aren’t mathematical, because the amount of mathematics in the book is minimal, and most of what’s there is conveyed verbally anyway. It is really the myriad of concepts and definitions of subatomic phenomena that are hard to keep in mind as the discussion proceeds. So, unless one has prior knowledge of particle physics, readers may find it useful to have notebook at hand to jot down the key ideas and definitions for speedy revision of what’s in previous pages. On the other hand, a glossary of terms provided as an appendix would reduce the problem. Therefore, although the publisher describes this introduction to string theory as ‘accessible and entertaining’, it is certainly not an easy read — even though it is well-written.

Having said this, the book certainly arouses one’s curiosity about the wonderful sub-atomic aspects of our world, and I found myself consulting Wikipedia for further elucidation of some the notions introduced in this book. But this was with respect to information about physics, and not mathematics. Indeed, having read the account of string theory in The Shape of Inner Space: String Theory and the Geometry of the Universe's Hidden Dimensions, by Yau and Nadis, I can say I feel more at home in the world of complex Kähler manifolds than in the zoo of particle physics. In this sense, I’m reminded of the following comment from Richard Feyman: ‘To those who do not know mathematics it is difficult to get across a real feeling as to the beauty, the deepest beauty, of nature ...’

Peter Ruane** **is retired from the field of mathematics education, which involved the training of primary and secondary school teachers. His postgraduate study included of algebraic topology and differential geometry, with applications to superconductivity.