On 20 Jul 2016 at 15:27, Christopher Hilton wrote:

>
> > On Jul 18, 2016, at 5:41 PM, xxxxxx@shadowgard.com wrote:
> >
> > On 17 Jul 2016 at 17:55, Christopher Sean Hilton wrote:
> >
> >> The upshot is that many people in the sectors I'm generating now
> >> live on vacuum worlds. If this isn't a bug in my program I'm almost
> >> thinking that one needs to impose a minimum tech level of 7 for
> >> vacuum worlds. But again, that's another story.
> >
> > Actually, it's possible to live on a vacuum world with mid-to-early
> > 1800s tech.
> >
> > Giant mirrors focus sunlight on solar boilers for steam power,
> > Electricity can be used to get metals from ores, etc.
> >
> > Life support is mostly plants under domes. And so on.
> >
> > *Getting* there may requyire higher TLs (though note that the last
> > bit of tech required to build an orbit capable rocket was invented
> > just before WWI)
> >
> > But once established, survival is possibleat the lower TL depending
> > mostly on the avialabilty of certain minerals and gases/ices.
> >
> > ps. it's also possible to run fission reactors with mid 1800s tech.
> > -
>
> I´d buy that. It would seem to me that keeping the habitat running
> with low tech wouldn´t be a problem. A 1920´s society building a
> vacuum habitat seems less believable to me. It´s academic as I
> hand-wavium that away IMTU by saying that a society which couldn´t
> build it´s own unnatural habitat must have a close relationship with
> a society that could build it.

Well, it's also a possibility that they've slowly *lost* bits of
tech. With a small population that's not that hard. Even with a
fairly large one being able to support some kinds of specialiss may
be too much work.

> As for living there. If I role play as an Imperial Citizen who´s
> aware of higher tech but living in a low tech society where habitat
> failure would be a complete disaster, I just wouldn´t stay in that
> situation for a long time.

Habitat disater is pretty serious even at high TLs!

But designing things properly and you'll only lose *part* of a
habitat. And unless it's something like a major meteor strike or
something equally damaging, air will take enouifgh time to leave a
section that many if not most people can make it to the airlocks and
get into the next section.

You want to restrict things to a certain size, and have their walls
be capable of sustaining full pressure on one side and vacuum on the
other.

Pressure walls (by analogy with firewalls) will divide things into
sections. Walls and structures inside a section can be more flimsy.
though they may have emergency pressure shelters inside (sort of like
tornado shelters in some parts of the US).

Vac suits will be rather clumsy in some ways (but not all ways). So
folks can go outside to fix things and build things. They just can't
don them in a hurry.

Some folks (especially emergency services) may have imported vac
suits. Rescue ball type things can probably be built with local tech.

doors between sections (even the big ones on roads) are going to be
pressure hatches, likely even airlocks. Since they have to handle
vacuum on either side they'll likely slide or "roll" rather than
swing. One example would be the airlocks on DS9.

Another would be the "garbage chute" airlock at the school in
Heinlein's Red Planet.

Figure on pressure walls and airlocks being of the "massively
overbuilt" sort.

Oh yes, you might want to check out this lost classic of SF: "The
Brick Moon" by Edward Everett Hale. It was published in 1869 and is
the first story to describe an artificial satellite.

https://en.wikipedia.org/wiki/The_Brick_Moon

It's on Project Gutenberg
http://www.gutenberg.org/ebooks/1633

--
Leonard Erickson (aka shadow)
shadow at shadowgard dot com