This important textbook is based on, though independent of, an educational TV series The Mechanical Universe broadcast on public television in the United States. Its aim is to guide students and general readers to an understanding of how the physical world works; physics is presented as a human endeavour, with historical development forming a thread throughout the text. The prerequisites are minimal, only basic algebra and trigonometry since the necessary calculus is developed in the text, with physics providing the motivation. New concepts are introduced at the natural, logical point with many historical references to place physics in a social perspective. Many topics from twentieth-century physics are included, for example energy, low temperature physics, relativity and black holes. The book is attractively and profusely illustrated and will be welcomed by students and also by general readers for whom this will be a stimulating alternative to other, less-thorough treatments.