Long Lives And Interstellar Distances

The Boat Of A Million Years, XIX.

Immortals are suited to slower than light interstellar travel. Immortality plus time dilation means that hundreds or thousands of light-years can be crossed provided that there is no need to return home soon. In fact, home changes so that it is no longer home. Starfarers become spatiotemporal exiles. The Allos whom Hanno and Yukiko call "Star Wing" has "...the patience of ancientness." (31, p. 576)

"These beings had left Pegasi fifteen thousand years ago; no individual lifetime of theirs was shorter than half of that. They knew of explorations that had been going on, in other directions, a hundred times as long." (ibid.)

So their shortest lifetime is 7500 years and their longest explorations so far have lasted for 1,500,000 years unless my maths are wrong. (I have to count zeros on paper.)

The (human) Survivors:

"...boost continuously between stars..." (p. 575)

- to maximize time dilation whereas the Alloi approach light speed but then go on free trajectory in order to save on anti-matter. Terrestrial astronomers never spot interstellar craft because they are few and because they expend energy only at the beginning nd end of a passage. Thus, Poul Anderson partly explains the lack of evidence for ETI's (Extra-Terrestrial Intelligences).

The Allos whom the Survivors call "Volant" thinks that human hastiness might fill a need left by other starfarers' patience. The Alloi and others have carefully explored a "'...tiny segment of the galaxy...'" (p. 576) whereas the Survivors might cross the whole galaxy and "'...weave it together...'" (ibid.) in less than a million years. The Alloi will accompany the Survivors to Phaeacia, the planet that the latter intend to colonize, in order to continue inter-species cooperation. This support in turn will ensure the success and survival of the colony.