If, like me, you've tended to think of string theory as a way that applied mathematicians and theoretical physicists can have endless fun without ever contributing anything practical to our understanding of the universe, Joseph Conlon's is a useful book to remind us that string theory isn't quite so unlikely and useless as it can seem. I must admit I've been strongly influenced by anti-string theory books such as Not Even Wrong and The Trouble with Physics . After reading Why String Theory? I have a more balanced view (if still being pretty doubtful of the theory's value). One thing that Conlon does, which I've never never seen elsewhere, is give a detailed description of it how the theory came into being, including the original, 26-dimensional approach that was an attempt to deal with the strong interaction. When this was trumped by quantum chromodynamics, it was almost as if the string theorists were so enamoured with their theory, which has s