In this latest effort to popularize the sciences, City University of New York professor and media star Kaku (Hyperspace) ponders topics that many people regard as impossible, ranging from psychokinesis and telepathy to time travel and teleportation. His Class I impossibilities include force fields, telepathy and antiuniverses, which don't violate the known laws of science and may become realities in the next century. Those in Class II await realization farther in the future and include faster-than-light travel and discovery of parallel universes. Kaku discusses only perpetual motion machines and precognition in Class III, things that aren't possible according to our current understanding of science. He explains how what many consider to be flights of fancy are being made tangible by recent scientific discoveries ranging from rudimentary advances in teleportation to the creation of small quantities of antimatter and transmissions faster than the speed of light. Science and science fiction buffs can easily follow Kaku's explanations as he shows that in the wonderful worlds of science, impossible things are happening every day.
Kaku (Parallel Worlds, Beyond Einstein, Hyperspace) introduces complex theories of physics to general readers. As The Economist notes, Kaku "makes a good stab at explaining difficult physics. But his grasp of his subject is perhaps trumped by his knowledge of science fiction." While Kaku writes in language designed to captivate nonscience readers, it's his references to pop culture—Star Trek to Terminator 3—that clarify his fringe physics. (Those wishing to explore the topic further can refer to Kaku's detailed footnotes.) To critics' delight, Kaku also investigates the moral issues of futuristic technology that SF does so well and asks provoking questions about the fate of humankind. The only complaints? Kaku omits a few obvious SF parallels, and, more seriously, readers who don't enjoy that genre may find less of interest here.