Kaku (Parallel Worlds: A Journey Through Creation, Higher Dimensions, and the Future of the Cosmos, 2004, etc.) provides lucid explanations of gee-whiz wonders from science-fiction books, television and films.
He divides 15 chapters into the not-impossible (invisibility, death rays, telepathy, power from antimatter), possibly impossible (time travel, parallel universes) and probably impossible (perpetual-motion machines, precognition). In ten of these chapters, Kaku cheerfully concludes that technical breakthroughs will bring these futuristic marvels into our lives, and he has high hopes for another three. Invisibility, for example, may be just around the corner: Researchers already divert light waves around tiny objects in the laboratory, and converting this into Harry Potter’s cloak of invisibility merely requires a few decades to a century of scientific progress. Death rays already exist in the form of huge lasers; the hand-held variety depicted in Men in Black will require ingenious miniaturization possibly achievable by 2100. Kaku has no problem with UFOs, despite concern that physical evidence for their existence remains steady at zero. Time travel turns out to be routine for subatomic particles. Human-sized objects would have to slip through a spatial distortion called a wormhole, a structure so poorly understood that even the supremely optimistic author cannot decide if it’s possible. Predicting the future requires the reversal of cause and effect; creating a perpetual-motion machine would mean changing the fundamental laws of the universe. Despite a mighty effort to find loopholes, Kaku reluctantly concludes that these seem unlikely. Readers are likely to trust his conclusions, since he is knowledgeable and authoritative about the latest technical developments in factories and research laboratories around the world, as well as in cutting-edge science.
A genuine tour de force, skillfully delivering cogent descriptions of everything from subatomic structure to the laws of the universe.