Non-locals only (was A buck a squafoot)

It's interesting that Robert Heinliens story "The Moon
is a Harsh Mistress" anticipated the unpleasant
aspects of the high frontier by analogy with the
Australian penal colony and came to the conclusion
that mainly those with nothing to lose would be the
most likely to settle such an adverse environment.
HAving said that I hasten to note, the current
political/economic environment will likely continue to
create a growing "under class", a large pool of
desperate people who might seek solace in such a
difficult environment as the early high frontier. Not
everyone in the western world is rich,,,

GAry 7

> > > > a first model habitat would be [...] quite
> expensive.
> > > What makes you say that? I have been estimating
> a shell cost
> > > on the order of $1/sqft of commercially-viable
> floor-space.
> > I'd like to see your figures. That sounds too low
> to me.
>
> My estimates are based purely on the
> placed-materials costs, since
> I am assuming that the non-marginal costs would be
> trivial. $1/sqft
> assumes a relatively brittle design, e.g.
> post-tensioned. For a
> relatively ductile design, e.g. no post-tensioning
> and a lot of PVA
> fibers in the mix, the cost would be closer to
> $10/sqft.
>
> Here is the main material:
> http://www.kuraray-am.com/pvaf/pva-ecc.php
>
> "Physically and mechanically, ECC behaves like
> normal concrete.
> Under tension, however, ECC behaves more like a
> ductile metal."
>
> At a typical fiber-fortification volume of 2%, the
> mass of fiber
> per cubic yard of "concrete" would be ~44 lbs. In
> small volumes,
> the fiber costs ~$3/lb. I am assuming that in
> colossal volumes the
> fiber might drop in cost to around $1/lb.
>
> Utilizing a mix incorporating high-volumes of
> fly-ash (HVFA), can
> save money since the Portland cement requirement is
> thus reduced.
> Two recent papers on this (full-text links):
>
http://ace-mrl.engin.umich.edu/NewFiles/journals(current).html
>
> "Use of High Volumes of Fly Ash to Improve ECC
> Mechanical
> Properties and Material Greenness"
>
> "Engineered Cementitious Composites with High-volume
> Fly Ash"
>
> > > I was thinking that controlling the day/night
> cycle would be a
> > > compelling feature anywhere.
> > Why?
>
> The world is moving toward an economy of pure
> information.
>
http://www.juliansimon.com/writings/Ultimate_Resource/TCHAR33.txt