Harry Potter’s cloak needs eyeholes
Physicist Michio Kaku explores the possibilities of invisibility cloaks, time travel, and other sci-fi wonders.
Michio Kaku is a physicist specializing in string theory at the City College of New York; it would seem he’s also a major Star Trek fan. The show, along with other science fiction classics, is a constant touchstone in “Physics of the Impossible,” his latest book, which invites readers to take a romp through the barely possible.
Kaku even uses Star Trek’s chief engineer, Scotty, to state the book’s starting point: “I canna’ change the laws of physics, Captain!”
Physics of the Impossible: A Scientific Exploration into the World of Phasers, Force Fields, Teleportation, and Time Travel is a popularization of physics and it reads like nothing so much as a thought-provoking manual for science fiction writers who want to get it right. Kaku takes 15 sci-fi staples, from invisibility cloaks to robots to parallel universes, and divides them up into Class I, II, and III impossibilities. Class I impossibilities are impossible at present, but could be just around the corner. No laws of physics forbid them. Class II impossibilities might be realized if humanity lives long enough and becomes advanced enough to take on such minor public works projects as particle accelerators 10 light-years long or “laser beams as large as a solar system or star cluster.”
Class III impossibilities are just plain impossible. Sorry.
But there are fewer truly impossible things than one might expect. Time travel is a mere Class II impossibility, for example. Kaku walks us through the history of and current thinking on each problem, making clear the technical hurdles and sketching out the possible solutions – all with a minimum of jargon and confusion. As long as one is somewhat familiar with, for example, what an electron is, the waters of incomprehensibility will only occasionally close overhead, and never for long. The latter chapters, dealing as they do with things at the very edge or on the other side of impossibility, are a bit heavier going.
Science fiction writers, even science-minded daydreamers, will find that instead of becoming disappointed with what is not possible they will more likely be inspired to new plot twists by the limitations of nature. Laser guns are perfectly possible ... if they are plugged in. (Until a portable power pack capable of delivering the oomph of a commercial power station is invented, space duels won’t be able to stray far from the surge protector. )
