I started reading books like this when I was quite young -- 13. I started with _Schrodinger's Cat_ and moved on to _A Brief History of Time_, and then started taking physics courses to get more information.<br>However, all  of this string theory should be new, even to undergrad college students.  Most college physics professors will only teach or even briefly touch upon  what is 100% confirmed. String theory is fascinating (if not confirmed) --  but you probably wont find it in a run-of-the-mill classroom.<br>The author  presents his information in a very convincing manner. Another reader said  "facts-about-to-be-proved" or somesuch. This is true. I find no  reason to disagree with his methods of explaining this theory and am rather  glad that he comes across like he does.<br>The book is not an _easy_ read --  I've had quite a few college physics courses and I found myself struggling  towards the end -- but it is a worthwhile read for anyone who understands  general relativity and/or quantum mechanics and would like to understand  where the two of them meet.<br>I would recommend the book to anyone.