First, despite being 20 years old, this book isn't particularly dated. Lots of questions about string theory still remain.

Greene writes very clearly as he describes first the theories of Einstein and of Quantum Mechanics, then why they don't reconcile with each other and how string theory brings them together--at least in theory. As a non-scientist, I am still not 100 percent certain how physicists can derive so many facts from an unproven theory, but Greene explains things about as well as it is possible to do so. I found it a compelling and not particularly difficult read. Before I read the book, I had watched Greene's PBS series based on it (and Greene's second PBS series based on his later book, The Fabric of the Cosmos.) This predisposed me to like the book and its author, since Greene's star power and ability to communicate complex ideas quite clearly is pretty amazing. If you're buying this book used, try to get a copy with the updated preface and epilogue. ( )

Green is one of the best at explaining concepts of science. ( )

Not bad, but probably the most difficult book I have ever read. I think I understood about 10% of it. ( )

Read in high school and opened my mind on why the teacher was actually burning for physics apart from the lame stuff he had to teach about. ( )

An excellent explanation of a theory we've all heard of but which few non-physicists, I fear, have much grasp of. Building up from the basics, through general relativity and quantum mechanics, Greene paints a phenomenally rich and compelling picture of superstring theory (and its derivatives) with analogies perfectly suited to make this ephemeral set of ideas intuitive. I'm convinced! A must-read. ( )