A post at SFConsim-l leads me to revisit a trope I have commented about here before. Space colonization, as imagined in SF and 'nonfiction' space speculation, is - surprise! - a riff on the English colonization of America, an experience shared by Clarke and Heinlein, albeit from different perspectives. Historically sort of colonization was driven first and foremost by cheap land.
This should be no surprise, any more than the American colonial analogy itself. It is like hydraulics. Provide a cheaper place to live and people will drift toward it, sometimes even flood toward it.
And the heart of the nutshell, as Heinlein once put it, is that there is no cheap land in space because there is no land at all. Land doesn't just mean a solid planetary surface (those are dirt cheap). Land means habitat, and in space the only way to have any is to build it youself. Which makes it expensive, especially since you have to build it up front.
Water can be pumped uphill, and people can be pulled toward expensive places to live by compensating attractions, or pushed there by pressures. But it is not a 'natural' process, and it can easily be reversed, hence ghost towns in rugged, played-out mining regions.
The sort of colonization envisioned in the rocketpunk era, most explicitly in books like Farmer in the Sky, but implicit in the consensus future history of the genre, is just plain unlikely, almost desperately unlikely, this side of the remote future or the Singularity, whichever comes first.
This is not the only possible sort of colonization. People have traveled afar, often spending their adult lives in some remote clime with no intention to settle there, marry, and raise a family, hoping instead to make their fortune and return home. The ones who don't make their fortune may end up staying, but that was not the plan.
Political colonialism often follows this pattern. The British colonized India, but I've never heard that any significant number of Britons settled there. (Human nature being what it is they did leave an Anglo-Indian population behind.)
A similar pattern has been common for trading outposts through the ages, whenever travel times have been prolonged. Even today, with one day global travel, people live abroad for years or even decades as expatriates, not emigrants. This, I believe, is a far more plausible scenario for the long term human presence in space than classic colonization. (And human nature being what it is, a mixed population will leave someone behind.)
Meta to this discussion - and not all that meta - is the delicate cohabitation of 'nonfiction' space speculation and science fiction. Space colonization has been driven first and foremost by story logic. For a broad range of story possibilities we want settings with a broad range of human experience. For this we want complete human communities, which means colonization in something like the classic SF sense.
But who are we trying to kid? Science fiction, particularly hard SF, is not known for engaging the whole range of human experience. This is no knock on it; all the branches of Romance are selective. The truth is that we want space colonies so that they can rebel against Earth, form an Empire, and generally play out History with a capital H, with lots of explosions and other cool stuff along the way.
I've suggested before on this blog that you can, in fact, get quite a lot of History without classical colonies. But another thing to keep in mind is that story logic doesn't necessarily drive real history. We may have an active spacefaring future that involves practically none of the story tropes of the rocketpunk era.
As a loose analogy, robotic diving on shipwrecks has done away with all those old underwater story tropes about divers trapped in a collapsing wreck, or bad guys cutting the air hose, but it has not at all done away with the somber magic of shipwrecks themselves, something the makers of 'Titanic' used to effect.
On the other hand, Hollywood has made two popular and critically acclaimed historical period pieces about actual space travel, and the stories are both an awful lot like rocketpunk.
Related posts: A Solar System for This Century.