Spreading Through the Galaxy

In the long run, it makes no difference whether we engage in millennial interstellar voyages on board slow boats or centuries-duration voyages on board fast ships. Human colonists arriving in an alien solar system must practice the skills learned close to home and rapidly learn to live off the lands on which they settle.

One wonders how quickly human civilization, or any extraterrestrial intelligence, can spread across the Milky Way Galaxy. If we use slow boats, the rate of interstellar colonization will be slow. Most stars are subluminous red dwarfs rather than solar-type stars like Alpha Centauri A and B. Colonies established around red-dwarf stars will have little incentive to expand to other stars because of the trillion-year lifetimes of such stars. Another limitation on the expansion rate from colonies in such systems is the low stellar radiant flux, which will greatly reduce the interstellar cruise velocity of the slow boats, and not help the prospects of fast ships.

Addressing these problems is a task for future generations. It is enough that the technologies we are beginning to apply today promise to open at least the nearest galactic frontier for our remote descendants.

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