Because this a relatively small book (physically) it sits somewhere between a full scale scientific biography and a short introductory guide. It's quick to read, compact and highly accessible. Gribbin makes a good tutor, providing an experience that is not unlike being lectured to by a slightly pernickety but insightful and friendly professor. (Pernickety, for instance in his careful insistence that it should always be the 'special theory of relativity', not the useful shorthand 'special relativity' (and likewise for the general theory), because it is the theory that is special/general, not the relativity.)
If I am honest I wasn't looking forward to yet another set of biographical information on Einstein. Not long ago, a reader sent me an email commenting that he had enjoyed one of my books, but he was a bit fed up reading yet another potted biography of the great man. There seems an obligation to do it, yet when you've read a few popular science books about relativity (or gravity, or light, or quantum theory) it does seem that, like Douglas Adams' bowl of petunias, the natural response to reading about Einstein's life should be 'Oh, no, not again.' But somehow, as if by magic, Gribbin manages to make the same old personal history interesting, with real insights that show the links between the man's life and work.
If anything, the biographical sections are a little more successful than those that concentrate on the physics. Gribbin knows his stuff (forwards, backwards and upside down), but the book's approach is just a bit too summary to give the best insight in the special theory and particularly the general theory of relativity. For instance, he gives the usual rubber sheet/trampoline with a weight analogy for matter producing a warp that bends a straight line path, but doesn't explain why this warp should cause a stationary object to start falling. The compactness means he doesn't show the actual equations of the general theory, which in compact form are beautiful and aren't difficult to be guided around, if not comprehended in detail. And he perpetuates the myth (as, I confess, I often have) that John Wheeler coined the term 'black hole.'
This isn't, then, a book for someone who wants to get their brains entangled around the nitty gritty of Einstein's theories of relativity, but it is an excellent way to get a feel for Einstein the man, and a simple, easy to grasp overview of relativity theory - an ideal marker for this centenary year.
Review by Brian Clegg