Xenology: An Introduction to the Scientific Study of Extraterrestrial Life, Intelligence, and Civilization

First Edition

© 1975-1979, 2008 Robert A. Freitas Jr. All Rights Reserved.

Robert A. Freitas Jr., Xenology: An Introduction to the Scientific Study of Extraterrestrial Life, Intelligence, and Civilization, First Edition, Xenology Research Institute, Sacramento, CA, 1979; http://www.xenology.info/Xeno.htm


Chapter 17.  Interstellar Voyaging


"Upon a slight conjecture I have ventured on a dangerous journey, and I already behold the foothills of new lands. Those who, have the courage to continue the search will set foot upon them...."
          -- Immanuel Kant (1755)

"Always listen to experts. They’ll tell you what can’t be done, and why. Then do it."
          -- Lazarus Long, in Robert Heinlein’s Time Enough for Love (1973)2601

"When a distinguished but elderly scientist states that something is possible, he is almost certainly right. When he states that something is impossible, he is very probably wrong."
          -- Arthur C. Clarke, in Profiles of the Future (1962)55

"There was a young lady named Bright,
Who traveled much faster than light,
She started one day
In a relative way
And returned on the previous night.
          -- Arthur Buller (1874-1944), in Punch, December 19, 1923

"Lacombe looked down into its...face. It was changing -- from something embryonic, unformed, into a face of something a thousand years old. Suddenly, Lacombe knew that all the wisdom, all the superintelligence, the experience it had to take to build these vehicles, to travel these dozens of light-years was there in the aging countenance and the...yes, the smile of this fantastic little creature."
          -- from Steven Spielberg’s Close Encounters of the Third Kind (1977)2729

"I must down to the seas again, To the lonely sea and the sky, And all I ask is a tall ship, And a star to steer her by..."
          -- John Masefield (1878-1967), in Sea Fever



Many reputable Terran scientists have argued, or attempted to "prove," that starflight is impossible or at least grossly unfeasible. (See Asimov,1403 Morrison,2750 Oliver,2749 Opik,2748 Purcell,1024 Simons,2361 and von Hoerner,1025 to name just a few.) However, in each case the only thing that was proven was that initial assumptions could be chosen to give the appearance of immense difficulty.

The fact is that without violating any of the principles of Einstein’s Theory of Relativity, an astronaut theoretically may travel anywhere in the known universe in less than a century -- faster, if he can stand the acceleration. Strictly in accordance with the laws of physics as we understand them today, a physical object may be moved from any point A to any other distant point B in as short a period of time as is desired. If you have the energy, it’s just a problem in engineering.*

As members of an emergent Type I civilization, we humans exhibit a natural tendency to measure the achievements of the future against the standards of the present and the limitations of the past. Dr. Edward Purcell, for example, has calculated that a 10-ton relativistic rocket traveling at 98% the speed of light over a 24 light-year round trip starcourse may require a propulsion system capable of handling 1018 watts of power. Since this is more than a hundred thousand times the current total output of humanity, such a proposition must be "preposterous"! Concludes Purcell, winner of the 1952 Nobel Prize in Physics: "All this stuff about traveling around the universe...belongs back where it came from, on the cereal box."

But let us look at this a bit more closely. Is a 1018 watt starship really preposterous? Even an early Type II stellar culture will have 1020 watts at its command. Humanity itself may well achieve this state of affairs just a few hundred years from now. Is it logical to assert that we would begrudge a mere 1% of our total energy output for an interstellar mission? It seems useful to recall that the mighty Saturn V rocket booster that carried twelve American astronauts to the moon developed more than 1011 watts in its power plant -- which represented roughly 2% of humanity’s total annual power output at the time.

It’s simply a matter of perspective. To a planetbound, 1013 watt developing Type I culture such as ours, a 1018 watt interstellar vehicle appears a fearsome project indeed. But to a 1020 watt early Type II stellar culture, a mission to the stars will seem no more unreasonable nor expensive than Project Apollo or the Space Shuttle seemed to us.

And to a mature Type II civilization (1026 watts), the dispatch of a 10-ton starship to neighboring stellar systems will represent the same relative drain on total energy resources as driving a Volkswagen automobile to market represents against the entire planetary power output of Earth.


* A complete bibliography of interstellar travel and communications has been compiled by Dr. Robert L. Forward.1680 Preliminary programs for interstellar exploration by mankind have been developed by Forward,718 Gillfillan,2845 Stine,672 and the Project Daedalus Study Group of the British Interplanetary Society.2953


Last updated on 6 December 2008