“The existence of plausible fastship concepts suggest[s] that once the available technology base has grown sufficiently large, small bands of explorers and pioneers will make the leap between stellar oases. How large the movement of people might be depends, of course, on the cost. If fastship voyages require a significant fraction of the total human wealth, they will be few and far between. We can estimate the relative cost. The sun outputs enough energy to permit 50,000 emigrants to leave the Solar System each second (if that were the only use of the gathered sunlight). If, by the time humanity is ready for the interstellar adventure, our descendants have managed to tap even a modest fraction of the solar output, they could easily afford emigration at a rate sufficient to sustain the human expansion. If we take the figure of 500 men, women, and children, a number suggested by studies of breeding populations among surviving hunter and gatherer peoples, as the minimum size of a genetically and socially healthy population, and if we stretch the launch period over a year, a collector 3700 km across will suffice to launch one such party each year. The need to carry a deceleration mechanism would increase the cost, which could be partially alleviated by building the collector closer to the Sun. The reader may make a private assessment as to the feasibility of such a system; but keep Clarke’s laws in mind and remember that human capabilities have a way of growing with time. We are not invoking dramatic scientific breakthroughs, just engineering on a very large scale by a people, our descendants, already used to living and working in space.”
From Finney, Ben R. and Eric M. Jones, “Fastships and Nomads: Two Roads to the Stars,” an essay in a collection the authors edited, Interstellar Migration and the Human Experience (Berkeley: University of California Press, 1985), pp. 94-95.
Centauri Dreams‘ take: Interstellar Migration and the Human Experience deserves a place in the library of anyone interested in our future in space. Long out of print, it can still be tracked down in used book stores or on the Internet. The book consists of the proceedings of the Conference on Interstellar Migration held at Los Alamos in May of 1983, and the range of its authors — biologists, physicists, historians, anthropologists — gives a sense of its multidisciplinary approach. There is simply no other book like it.
