for entertainment Lively Mathematics Physics Everywhere Tricks and Amusements Physics Can Be FunHe has also written several books on interplanetary travel (Interplanetary Journeys, On a Rocket to Stars, and World Expanses) Physics for Entertainment In 1913, Russian bookshops began carrying Physics for Entertainment. The educationalist's new book attracted young readers seeking answers to scientific questions.Physics for Entertainment had a unique layout as well as an instructive style. In the preface (11th ed.) Perelman wrote: "The main objective of Physics for Entertainment'' is to arouse the activity of scientific imagination, to teach the reader to think in the spirit of the science of physics and to create in his mind a wide variety of associations of physical knowledge with the widely differing facts of life, with all that he normally comes into contact with." In the foreword, Perelman describes the contents as “conundrums, brain-teasers, entertaining anecdotes, and unexpected comparisons,” adding, “I have quoted extensively from Jules Verne, H. G. Wells, Mark Twain and other writers, because, besides providing entertainment, the fantastic experiments these writers describe may well serve as instructive illustrations at physics classes.” The 13th edition (1936) would be the last published during the author's lifetime. Among the book's notable topics was the idea of a perpetual machine: a hypothetical machine which could run incessantly performing useful work. The author discusses perpetual motion, highlighting many attempts to build such a machine, and explains why they failed. Other topics included how to jump from a moving car, and why, “according to the law of buoyancy, we would never drown in the Dead Sea.” Randall Munroe, the creator of the web comic xkcd and author of his own popular science books, wrote: The book is a series of a few hundred examples, no more than one or two pages each, asking a question that illustrates some idea in basic physics. It’s neat to see what has and hasn’t changed in the last century or so. Many of the examples he uses seem to be straight out of a modern high school physics textbook, while others were totally new to me. And some of the answers to the questions he poses seem obvious, but others made me stop and think. [This] diagram ... shows a design for a fountain with no pump — it took me a while to get why it works.... Later in the book, he explains the physics of that