It's a 1000 page book--I will update this review if I have signficant changes of opinion in the last 800 pages.<br><br>There is plenty of material accessible to those who have not studied college-level mathematics, but so far, not much percentagewise.  By that, I mean, there are lots of pages of material that doesn't go heavy into mathematcs, but there are more pages (in the first 200) that do.  Still, if you skip over the parts that are not interesting to you (or even scan them to get a flavor of what higher mathematics is without getting bogged down into details), there is plenty to read , especially at the very beginning which is a brief and fun-to-read history of attempts to come up with a theory of everything.<br><br>For those who have studied and have an interest in higher mathematcs, it has a good summary of much of college and some graduate-level mathematics, allowing one to review what they have forgotten, or get a flavor for subjects passed over--it may even inspire more in-depth study of some of these subjects (it inspired me to get out my old copy of Rudin's Real Analysis and read the chapter on Differential Forms, a topic not covered in the analysis classes I took).<br><br>In conclusion, it's a very extensive book that attempts to both explain the latest and greatest attempts at theories of everything, both (intuitively more than rigorously) mathematically and qualitatively.  I recommend it for a mathematician or one mathematically inclined who wants a review of mathematics or wants to learn some physics.  I also recommend it for anyone who wants to learn physics and doesn't mind that a lot of the pages will be heavily mathematical but (the author promises) not necessary to read to gain a lot from the book.