OK, I haven't actually read it, but it looked like a really good book for learning a lot of interesting math when I thumbed through its contents at the library. :)
This is not a good book for someone who doesn't know math. He's on to hyperbolic geometry by ch 2. (unsuccessfully) reading this book was one of the things that convinced me to back to school to study more math :-)
I agree with hyperbovine -- Road To Reality is a downright terrible book for the casually-interested nonprofessional, and I don't understand why it gets recommended so frequently. Roger Penrose is a bright fellow and a good writer but this book is not for the person who did OK in high school math and physics and now wants to take it to the next level.
http://www.amazon.com/Road-Reality-Complete-Guide-Universe/d...
OK, I haven't actually read it, but it looked like a really good book for learning a lot of interesting math when I thumbed through its contents at the library. :)