Tuesday 12 March 2019

Near Light Speed

Interstellar spaceships are faster in the Directorate History than in the Rustum History. At one gravity acceleration, they reach near light speed in a year and need another year to decelerate. Speed and time dilation make the intervening time brief. Passengers are in suspended animation while the crew stands watch. Captain Kahn reads history and has experienced some of it. He was born before the Directorate and his father was a radiation technician in the Solar War. Thus, there are hints at a future history.

A few hundred human beings have lived for four generations on Mithras but Kahn says that genetic drift would destroy such a low population in time. Would it?

3 comments:

Sean M. Brooks said...

Kaor, Paul!

I don't know anywhere near enough about genetics or biology to emphatically say that a few hundred humans on Mithras provides too thin a genetic basis for a colony, as distinct from a mere base, could survive. But we do see Poul Anderson saying over and over in various stories that a large population is needed for an off Earth colony to have the variability in genetics needed for survival. Recall how there was concern that the 3000 Constitutionalist exiles who settled Rustum did not have enough genetic variability. So this was eked out by using donated human sperm and eggs to conceive exogene babies.

Sean

Jim Baerg said...

I think the genetic variability would *probably* be enough, but how many people do you need to have the technical specialties to maintain a technological culture?

In part of "Guns, Germs, and Steel", Jared Diamond writes about the situation total isolation in Tasmania between when rising sea level cut off Tasmania from mainland Australia about 10000 years ago, and the arrival of Europeans in sailing ships.

Tasmania could support a population of about 4000 hunter-gatherers indefinitely. During their isolation they *lost* some of the technologies they had when they first became isolated. Perhaps the people who knew how to make bone needle died in a famine and the tech wasn't reinvented. Perhaps some techs were given up because of a 'fad', see Japan giving up guns, or Germany giving up nuclear power. Though in both the latter cases the culture in question could relearn the tech from neighbors.

It would take serious planning to have enough technical specialist among an initial population of 3000 to maintain eg: an early 20th century tech level, with enough records to establish higher tech as the population increased after the colony was established.

Sean M. Brooks said...

Kaor, Jim!

I lea more to Anderson's view that at least a fairly large population would be needed for an off Earth extra-Solar colony to survive. Esp. on planets like Rustum. And I agree with you that any colonists should have a large library of stored data to use as population grows.

Very terrestroid planets like Mithras would be far easier to colonize, if they don't have native intelligent races.

Ad astra! Sean