I was not impressed with this book. There are very few books that I find really painful to read and this was one. I felt that an editor should have sat down with this author and hammered home some points: know your audience, pitch it consistently to the level of audience you have in mind, keep it simple, be descriptive, be complete as possible. Instead, I felt this book was written by an antsy adolescent wanting to blurt out the "punch line" way too early while dropping details that are never woven into a consistent narrative.
This book should not have been published. It is the kind of thing you expect from a "vanity press" not from a serious university press like the Princeton University Press. Whatever editors there were simply gave up and let Gubser's manuscript through with no review and no editing. That's a shame. The public wants and needs a good introduction to string theory for the informed, but non-specialist, reader. This is not that book.
Gubser has three "background" chapters supposedly to lay the foundation for a discussion of string theory. Then he has three chapters on string theory and special topics in the field. Finally he has two chapters on current high energy particle physics experiments. That's three books crammed into 160 pages!
If I was Gubser and I was trying to keep my book "manageable" in size I would have excised the three "background" chapters and simply noted some popular texts to read to get the necessary background. That would free up 35% of the pages to fulfill his promise to explain string theory.
Similarly, the last 40 pages on experiments are interesting but useful only if the primary goal of explaining string theory has been successfully completed and the "extra room" is available. Well, they the middle section failed in its task, so it was a complete waste of space to indulge in these pages.
This book fails in it proclaimed mission. It does not in any way assist an informed, intelligent general reader to understand string theory. The title of the book is an example of the hubris of this author. Instead of writing "a book on string theory" he wrote "the book on string theory". Well, I'm sorry to say, this might be a book with string theory details in it, but it isn't the book that any outsider can recognize as a coherent introduction to string theory.
One habit of this author was to announce a topic and promise to discuss it in detail later. Then at a later point dither a bit with the topic while not explaining much of anything. Then at a later point reference back with the claim the a "full explanation" was presented earlier in the book. Rather than wasting all these words making idle promises and then boasting of accomplishments, more effort in getting the basic description/explanation done would have been far more helpful. As I read I kept thinking of classic science writers and wished desperately that this academic would have availed himself of the help that an accomplished writer could offer.
Here's an example of the turgid, muddled, non-explanatory prose:
You may recall that when I discussed strongly interacting string theory in the previous chapter, the upshot was that a new dimension opened up. I claimed that string theory starts behaving like it is actually eleven-dimensional, not ten-dimensional. That's pretty different from what I explained in the last few paragraphs. In fact. I had in mind a different string theory. The one that grows an extra dimension when the string interactions become strong is called Type IIA string theory. It has D0-branes, D2-branes, D4-branes, D6-brands, solitonic 5-branes, and some other objects that are a bit harder to explain. When the string coupling is strong Type IIa string theory is best described in terms of eleven dimensions. But Type IIV string theory at strong coupling is best described by swapping D1-branes for strings, without doing anything funny with extra dimensions.That's 141 words that don't explain a thing. These could have been excised from the text and not missed. Instead of using this space to put in 141 words that actually advanced the reader's understanding, the author flaunted a lot of fancy words and the illusion of "explanation" without delivering anything to the reader. The book is rife with this kind of "description" and "explanation" that is meaningless verbosity!