And now for something completely different...
I don't know enough about string theory to comment on the validity of Kaku's argument, I have to admit that is the part of the book that went a little bit over my head. (Maybe on a re-read I'll understand it a little better). But it is a book that I very much enjoyed reading. Along with the heavier stuff there are anecdotes and observations that lighten the read a little.
"When Einstein kept repeating that God does not play dice with the universe, Bohr reportedly said, "Stop telling God what to do."
I am reasonably familiar with Classical Physics - Newton, Faraday and Maxwell - so sailed through the first part of the book. The middle bit which covers quantum mechanics I didn't do too badly with. But string theory covered in the last part of the book left me bemused in places and I seemed to lose the ability to comprehend and my brain lost the ability to cope. I wish there had been more on string theory and explanations as I was really having to concentrate on the concepts and I wasn't always up to it.
One of the things that made me smile is where he says (at the beginning) that he hopes that the book will give you a balanced objective analysis of string theory's breakthroughs and limitations and then admits that he does have somewhat of a stake in string theory as he's been working on it since 1968. I like that there is humour among the serious science. I also like the way he relays the snarkiness and sarcasm that occurs between the various scientists over the years.
I think for someone who is familiar with quantum mechanics and string theory this book will feel like too broad an overview, a skimming of the surface of everything. But if you are looking for an introduction to the major ideas and breakthroughs of physics and where physics is heading this is very readable and the concepts of Newton, Maxwell and Einstein are explained clearly.
(I received a free ARC of this book to review)