Friday, 14 September 2018

Extasolar Colonization

In Colonization, I said that I had read somewhere that colonization increases population pressure. In Population Pressure, I said that the statement is in James Blish's The Seedling Stars. It is here:

"If the Authority knew that emigration increases the home population rather than cuts it, the Authority carefully refrained from saying so to the governments involved; they could rediscover Franklin's Law for themselves."
-James Blish, The Seedling Stars (London, 1972), Book One, 3, p. 50.

Context: the Greater Earth Port Authority offers to terraform Mars at great expense and the governments "...needed to get rid of their pullulating masses by the bucket-full..." (pp. 49-50)

Question: Franklin discusses expanding populations in the colonies but does he also refer to population expansion back home?

Poul Anderson discusses extrasolar colonization for political dissidents in the Rustum History and for those willing to make a fresh start with low technology in the Technic History (for the latter, see here) and interstellar trade in the Technic and Kith Histories.

James Blish addresses interstellar trade in the Okie History, extrasolar colonization in The Seedling Stars and instantaneous interstellar communication in The Quincunx Of Time. These three ideas began as a single series but diverged.

5 comments:

Sean M. Brooks said...

Kaor, Paul!

I looked up the link to Franklin's essay, and the article did say Franklin believed population in Europe had reached the carrying capacity of the land. So, yes, Franklin did discuss the issue of population expansion "back home."

It's my belief that Poul Anderson enunciated more accurately than most the most likely reasons why colonies will be founded off Earth. After all, those reasons seems to be what motivates Elon Musk at SpaceX!

Sean

paulshackley2017@gmail.com said...

Sean,
But did Franklin say that emigration would increase the home population?
Paul.

Sean M. Brooks said...

Kaor, Paul!

According to the Wikipedia article, no, that was not so. It only said Franklin believed Europe (and the UK) had reached its natural "carrying capacity." So colonization should not, by itself, caused an increase in the "home" population. But I know I should read Franklin's essay to be sure of what he thought.

Sean

S.M. Stirling said...

"Post hoc propter ergo hoc"; the fact that A precedes B does NOT mean that A -causes- B.

If a country has emigration, and its population increases, it does not follow that the emigration caused the increase.

Quite the contrary.

If people (particularly a sample skewed towards young adults, the primary reproductive group) leave a country, that decreases its population or decreases its rate of population increase... other things being equal.

But other things aren't equal, of course.

Eg., if the death rate is decreasing at the same time, or the fertility rate increasing, then population will increase despite -- but not because of -- the emigration.

Historical example: Ireland after 1846-48.

Of a population of about 8 million, a million died in the Famine. This would by itself have been a temporary check if the other demographic constants had been maintained; Ireland had a substantial surplus of births over deaths, except for the big spike during the Famine years.

But other factors weren't maintained; the average age of marriage increased, the number of never-married people -- religious celibates, bachelors, spinsters -- increased, and emigration increased massively and stayed high as people developed a pattern where only the heirs to farms and trades were allowed to marry, and the others had to emigrate or remained celibate.

After 1850, Ireland settled back into a pattern where fertility exceeded mortality by a substantial, though much reduced, margin. The overall population continued to decline, and has pretty much continued to decline right down to the present, due to emigration. The death rate -plus- the emigration rate (and its subtraction of breeding-age people) exceeded the birth rate.

As an aside, emigration from Ireland allowed people to maintain a fertility rate that included a "safety margin" of extra children to ensure that there was an heir and a marriageable daughter by the time the children reached adulthood, the safety margin guarding against mortality. if the spares weren't needed, they could leave the country. Having only 2 children would have been very risky, given 19th-century disease patterns. If emigration hadn't been available, people might well have reduced the size of their families further and accepted the risk, but that's speculative.

In most cases, emigration was a symptom of the same rapid population increase that was occurring anyway because of other, unrelated factors. Often the modernization process that was increasing population growth(*) also increased mobility, between rural areas, between rural areas and towns, and between countries.

The emigration -reduced- a population increase that was going to happen anyway.

(*) social changes in 18th-19th century Europe made it easier for people to marry and to marry earlier, in most places.

Sean M. Brooks said...

Dear Mr. Stirling,

And your comments here demolishes Benjamin Franklin's argument.

Sean