This is what really bothers me about most popular physics books! Somehow the publishers convinced the writers that if they show real math formulas, the book sale will suffer heavily. Whether it is true or not, it sure made this book look much dumber than it could be and wasted a lot of paragraphs describing relations where a simple notations would have sufficed. However, the author did a good job tacking an extremely complex and truely convoluted current view of how string theory fits in theoretical physics. Although he presented an optimistic view of how string theory may solve many intractable issues, the big picture remains to be very elusive on how it all fits together and what directions the theorists are taking to update the standard model.