Can we change the past? The surprising answer to this question can be found in the final chapters of this book. Examining the history of the study of time and presenting in detail the modern state of physical research on the subject, this book is a superb overview of a fascinating subject. The figures who have helped to shape our views on time are presented as real people, in the context of their own times and struggles: from Socrates' troubles in Athens, to the experiences of physicists under the former Soviet Union. In addition Novikov details his own experiences with great Russian and Western physicists, such as Sakharov, Zeldovich, Rees and Hawking. Details of modern theories in fields such as the possibility of time machines, anomalous flows of time (at black or white holes) and the possible source of The River of Time are described with authority and clarity.