I won’t pretend to understand even a small amount of the physics behind the principles and theories presented in this book, but to my relief it’s not necessary to be good at physics to derive great enjoyment and edification from reading it. Kaku has a comprehensive grasp of his material; that much is clear. But his intent is to explain it in terms that almost anyone can understand.

He begins at the beginning of the twentieth century and launches into a short history of the modern space program, including looks at the Russian rocket scientist Tsiolkovsky, the American rocketry pioneer Goddard, Von Braun and the V-2 rockets, the cold war space programs of the United States and the USSR, Sputnik, the Apollo program and the moon landings, the space shuttle era, the International Space Station, and other milestones. Next, he discusses plans for further exploration and colonization of the solar system, including the moon, Mars, and some of the moons circling the gas giants. He writes of mining materials from moons, planets, asteroids, and comets.

He’s just getting warmed up, though. He then launches into an explanation of how robots could assist humankind in the mining, colonization, and exploration of the solar system and other nearby and distant star systems. He describes what it would take in terms of materials, expense, and time to construct a starship for galactic exploration. He discusses the concepts of multigenerational starships, various possible propulsion systems for starships, and the planets that have been discovered that might possibly be suitable for human habitation.

And that’s not all. He goes into immortality as an aid to space exploration and how immortality might be achieved. He explains how the human body might be adapted to enable it to survive on worlds starkly different than our own. He talks of the search for extraterrestrial life and the possibility of advanced civilizations in other parts of the galaxy. He even goes beyond that to discuss various theories about the eventual demise of our universe and how incredibly advanced civilizations could escape the death of our universe by accessing other universes.

To take these last steps, Kaku gives simple explanations of Einstein’s theory of relativity, quantum theory, and string theory. I have to admit that he lost me a few places in these last sections, but I think I got the gist of it.

The value of this book is in its overview of current theories of physics in language designed to be understood by non-specialists. It’s a great tool for writers like me who venture into the realm of science fiction for literary purposes without having a background in science. Kaku has a gift for making incredibly complex thoughts easy to understand. I don’t need to grasp the mathematics that lie behind the ideas that he puts forth; it’s enough for me to be familiar with the basic concepts so that I don’t commit egregious errors in my stories. This book provides me with that cushion. It’s a general overview that is at the same time amazingly meticulous in touching on all the important major topics having to do with humankind’s current and future space exploration. Highly recommended.