--- In sfconsim-l@yahoogroups.com, Kveldulf@... wrote:
>
> <<--- On Thu, 11/5/09, Anthony Jackson <ajackson@...> wrote:
> >>Isaac Kuo wrote:
> >
> >>>What is the 3 generation rule?
> >
> >>Artificial habitats without external support usually don't
> >>last more than three generations. This is in part a handwave
> >>for putting colonies on worlds in the 10W setting, but
> >>underlying logic appears to have something to do with a
> >>tendency for the middle generation to underinvest
> >>in infrastructure that will be needed later. >>
>
> Who created this rule?

Ken Burnside, who hasn't been around here alot lately.

> Personally, I don't buy it as a rule; maybe for disfunctional habitats,
> but not for the majority of the population.

From what you write below, I think you do buy it (at least alot more than some
people on this list do).

> For the foreseeable future, the only folks with the money to build a
> space habitat in the first place will be governments and large
> corporations. These will be highly organized, intentional communities
> and while they - like any human community - have their dissidents, they
> will as a rule be socially coherent.
>
> A space settlement will by definition select people for their skills,
> work ethic and ability to work well with others. The enterprise is much
> more likely to resemble a military enterprise or construction and
> operation of a new manufacturing plant than it will resemble the
> somewhat scattershot colonial efforts of the past (such as the earliest
> European settlements in the now United States). Modern creation of new
> settlements have mostly failed due to wrong assumptions or conflict
> with indigenes (not an issue in space) or changed economic conditions
> (all those abandoned mining and industrial colonies from the 19th
> century that dot the globe for instance).
>
> If anything, I'd guess the single biggest reason for failure of a space
> habitat would be economic. After initial setup, unless the habitat can
> either generate economic value (say, zero G manufacturing and/or
> research) or serve a useful purpose (a fueling station for ships
> heading to the outer system, basic research such as astronomy) it will
> become a money-losing white elephant for the parent entity. Once it
> becomes no longer economically valuable, no matter how motivated its
> inhabitants may be it will eventually wither on the vine and be
> abandoned.

This type of space settlement is not what the three generation rule is arguing
against. It's small, composed of trained workers, and being there is a job, not
a life. The type of settlement that the three generation rule is an argument
against is the one you describe below:

> If settlements became common, you'd get a broader range of human
> communities (religious colonies, would be utopian communities, etc.).
> Only then when you start seeing a broader range of human societies and
> personalities involved in founding habitats would you get more failures
> (the success rate of small business startups might be a useful guide)
> and something like the "3 generation rule" might come into effect.

It's when colonists' children and grandchildren (thus "3 generation rule") start
contributing to the maintenance/growth of the colony more than new recruits from
home that the 3GR really starts coming into effect. Another transition point
that's probably of significance for the 3GR is when the colony starts to really
have its own economy, rather than just being a few numbers on the balance sheet
of a company or nation. Political independence is another important factor.

Ken did suggest that the 3GR might be mitigated by a strict, hierarchical,
disciplined, and in his words "Bedouin" style society.

> That's my 2 cents..
>
> Andy
>
> PS - I don't think anyone needs to invoke a 3 generation rule to
> explain why planet or moon-based colonies would be founded in addition
> to space colonies. Let's face it, a ground colony is much simpler to
> build and maintain, and depending on exactly where it is located it
> likely has a much greater margin of error if something goes wrong.
>

Very true for Earth-type worlds, if any exist out there. Possibly true, but very
likely not true enough for Moon and Mars type worlds (which would be only a
little better than open space, if at all, and would be at the bottom of a
gravity well to boot). Not at all true for worlds like Venus or Titan, where a
thick atmosphere at a very different temperature from what the colonists would
need would cause alot of trouble.

Very likely, unless there exists both a method of faster-than-light travel and
an Earth-like world in very close proximity, the 3GR means no colonies beyond
Earth itself. Maybe some fairly large space stations, scientific outposts, maybe
even off-Earth factories if there is a valuable enough product that can only be
assembled in zero-g but can be used on Earth, but no permanent, economically,
politically, or reproductively independent colonies anywhere but on this planet.