Book Review: Centauri Dreams

First a bit of a background. We’ve a long way to go. Alpha Centauri is 4.3 light years away (about 13 zeros after the one when considering kilometres). Voyager 1, the fastest man made object, is speeding at 3.6 AU’s per year (about 8 zeros after the one in kilometres per year). Were a person to be on it, some 100,000 years would pass before entering Alpha Centauri’s solar system. This won’t happen as Voyager 1 travels another path, but this is the problem in a nutshell, it’s too far for today’s chemically driven rockets. With most people expecting a return on investment well within ten years then there would be little support in waiting thousands of generations for payback. Given this impracticality Gilster presents options and methods that might reduce the travel time to within one generation.

The first chapter sets the background of who’s doing what, where they are keeping themselves busy and, sometimes, when their activities first appear upon the scene. Scores of researchers’ names arise, especially physicists, mathematicians and astronomers, but a sprinkling of other esoteric specialists such as Internet designers, clearly demonstrates the broad response to this challenge. NASA’s programs and facilities predominate. CERN appears as does the Brookhaven National Laboratory. Early visionaries from the 1800’s and even earlier make a brief appearance. Applicable science fiction stories from the early 1900’s get noted, while the predominance of technically valid work dates from about 1960 on. This shows that on the whole, considerable thought and work has gone into advancing concepts for high speed interstellar travel.

Five chapters follow and represent the real meat of this book. These look at different methods of getting a useful payload to our neighbouring stars and they focus on well known and lesser known means of propulsion. Antimatter, sails, ramjets and fusion runways get their dues. Field-drives, providing force from the interaction of matter and fields get an honourable mention. Each chapter clearly and simply describes the methods of the chosen propulsion and the state (or technical level) of the research. Interviews with today’s investigators provide a superb insider’s view of activities. If you’re looking to identify locations for grad studies, there is a bonus as key investigating sites get identified alongside. Exciting sections detail the latest in experiments and technical investigations. The Planetary Society’s solar sail lifts off soon, antimatter is getting expansive new containers, lasers push model crafts up against Earth’s gravitational pull and a mini-magentospheric plasma propulsion prototype undergoes testing. Each of these might answer the riddle about how we propel ourselves at near light speed but as pointed out, the breakthrough technology may yet be around the corner.

One chapter seems a little bit like a lost child. This deals with communication and guidance. Of course these issues will need to be addressed, but it seems a bit early to be worrying about setting up extra-planetary webs or designing their communication protocol for that real long distance feeling. The guidance/navigation portion seems equally out of place. As the propulsion method so drastically constrains the mission, this discussion is preemptive. Still, as the title states, this book plans for interstellar exploration, hence communication and guidance are relevant and their consideration is warranted.

And yes, the title says it all. Alpha Centauri is a dreamers destination but dreams are only the beginning. Imagination gets us out of the constraints of everyday thinking and planning will see that effort gets well applied. As depicted within the book, many people share this dream. Some are incredibly lucky and can make it their life’s work. Others contribute directly in their part time or indirectly whether through related research, writing fiction or, as Gilster is undertaking, performing outreach activities. The link from imagination, to serious consideration and eventual trials constantly arises as either a sign of humanity’s adaptability or perhaps a sign of genetic coding. Nevertheless, time and again, imaginations are shown to conceive of the knowledge that thrusts plans out of the realm of fiction and into the laboratory where researchers make it reality.

Stars twinkle all about us at night. Perhaps maliciously inviting or teasing like a temptress, either way they remain today too far to fathom visiting today. Science fiction had imaginaries who gave detailed if somewhat fanciful means of propulsion between the stars. Paul Gilster in Centauri Dreams: Imagining and Planning Interstellar Exploration shows that real science is advancing technologies that could make this trip practical. The plans of the scientists and other technical may soon bear fruit and future generations of humans would have a much better and more exciting life amongst the stars.

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Review by Mark Mortimer