Is the impossible possible?

Any sufficiently advanced technology is indistinguishable from magic.

Arthur C. Clarke's third law

Michio Kaku's Physics of the Impossible was published in 2008, making much of the science dated. Even so the theoretical physicist's book will amaze readers, especially those of us with relatively little knowledge of science. We may also be amazed at how much of his book we can actually understand.

Kaku enjoys science fiction novels and movies, and like the rest of us who enjoy these stories he wonders if time travel might really be possible. Could space travelers ever exceed the speed of light? Could someone ever be teleported from one place to another, as on various Star Trek episodes? Might the light sabers and Death Star of Star Wars ever become reality? Is invisibility scientifically possible?

To such questions, Kaku usually answers yes, or at least maybe. Some of these may be just decades away, while others may be centuries away. He writes, for example, "There is no law of physics preventing the creation of a Death Star or light sabers." Common sense tells us time can never go backwards, but Kaku writes, "the mathematical equations of subatomic particles tell us otherwise."

To accomplish most of these impossibilities, however, will require much more energy than human beings can now produce, the author warns. Finding cheap, abundant energy must come before time travel and invisible men.