As a book about superstring theory this is a miserable failure. Ploughing through 206 pages in three days has left me still knowing almost nothing about this theory of particle physics which is still undergoing bleeding-edge development fifteen years after the book's publication. Kaku seems to get so embroiled in some sort of vindication of superstrings, citing multitudes of problems in physics which, he claims, could be solved using superstrings, that he forgets to actually explain this wonder theory. We are told, in a rather confused and incoherent manner, that superstring theories operate variously in eight, 10, 11 or 26 dimensions. As a result they have "the largest amount of symmetry ever found in a physical model". In fact, they possess the collosal symmetry E(8)×E(8), and the power of superstrings is unleashed by breaking this symmetry. Apparently.

That is the gist of the central part of the book, "Supersymmetry and Superstrings". Part I - "A Theory of the Universe" - is the same old history of the universe through which pop-science readers drearily plod with each new volume, and it is by no means the best of its kind. Part III, "Beyond the Fourth Dimension", is full of whimsical discussions of hyperdimensional space, unprovable creation theories, parallel universes and the like. A whole chapter is devoted to dark matter, which Kaku discusses as if it really exists (admittedly, it was thought that dark matter really did exist in 1987, as MOND was only four years old). The appendix to the 1997 edition totally fails to add any information, although here Kaku did have an opportunity to redeem himself, which he passed up in favour of more hidden-agenda parading of superstring theory as the answer to everything. The lasting impression that the book left me with was that, whatever this theory may be, Michio Kaku likes it a lot.

And, hey? I think the idea may be that the universe is tied together with string. This book would surely benefit from the same treatment. Here is a message for John Gribbin: Please write us a book about superstring theory. Your fans need you.