Physics of the Impossible by Michio Kaku

Physics of the Impossible: A Scientific Exploration Into the World of Phasers, Force Fields, Teleportation, and Time Travel is a book by theoretical physicist Michio Kaku. Kaku uses discussion of speculative technologies to introduce topics of fundamental physics to the reader. The topic of invisibility becomes a discussion on why the speed of light is slower in water than in vacuum, that electromagnetism is similar to ripples in a pond, and Kaku discusses newly developed composite materials. The topic of Star Trek "phasers" becomes a lesson on how lasers work and how laser-based research is conducted. The cover of his book depicts a TARDIS, a device used in the British science fiction television show Doctor Who to travel in space and time, in its disguise as a police box, continuously passing through a time loop. With each discussion of science fiction technology topics he also "explains the hurdles to realizing these science fiction concepts as reality".