The book takes the relatively complex concept of vector dynamics within different frames and cuts it into bite size chunks. I am currently taking Paley's class and he really knows his stuff. He is able to connect to young students who sometimes have trouble wrapping their head around this stuff WITHOUT ever patronizing or getting angry (probably because he is pretty young himself). I would have to say this is my hardest semester in school so far and this book and this class is the hardest, but favorite.