From space elevators to interstellar travel, science fiction and fantasy writers have come up with some brilliant, innovative ideas. Yet how plausible are these ideas—for instance, could Mr. Weasley’s flying car in the Harry Potter books really exist? Which concepts might happen, and which ones wouldn’t work? From the works of Ursula K. Le Guin to and , this book delves into the most extraordinary details in science fiction and fantasy—such as time warps, shape changing, and rocket launches—and shows readers the physics and math behind the phenomena.