This book, is without a shadow of a doubt one of the best reference books for modern physics available to date. Einsteins theory of relativity, the pricipals of quantum mechanics and superconductivity are explained completely in just a few pages. It is easy to understand, enjoyable to read through (as well as use for reference) and there are examples and practice questions to ensure that you thoroughly learn what has been said. I am 17 years old, and I believe I completely understand special relativity, the meisner effect and much more in the line of theoretical particle physics thanks to this book. Definitely worth the price!!! You will never have another unanswered question again.