My mental muscle for math has definitely atrophied since graduating with an engineering degree. I’ve been looking for a nice way to exercise it, and this looks like something that can get me there.
For a more in-depth discussion of physics, I’ve found the Feynman Lectures [1,2] to be quite enjoyable. It’s a long read (I’ve only finished the first book) but it is very thorough.
[0] http://www.amazon.com/dp/0486409163/ (Mathematics: Its Content, Methods and Meaning)