This book is different from other books of similar content, not in term of the material it contains but in term of the way this material is presented. It contains fascinating puzzles and stimulating quizzes designed to assess the reader knowledge of physics. While seemingly simple, the puzzles and their solutions often surprise the readers, allow them to understand some of nature’s fundamental laws, and use them in their daily lives. Immensely instructive and entertaining, it has been one of the best sellers in Russia during the first part of last century.