On 5/4/22 15:45, Jonathan Clark - jonathan at att.net (via tml list) wrote:
> Bill Rutherford wrote:
>
>> Is this because after a zillion years, every system WOULD be populated?
>
>> Or do the various canon maps only show systems with populations, star
>> ports, or other importance,and it's assumed there are other stars in
>> the empty hexes that are essentially useless for travelling via jump?
>
>> What about stars without planets?
>
In my Advisoryverse TU, _some_ sort of large mass is required to get the
jump mathematics to converge to make controlled jump even possible.

A free-flying habitat in some sort of stellar orbit would not be out of
the realms of possibility, but (to support starship traffic), where do
they get the hydrogen from?

> My take, FWIW... (These ideas may not be well thought out, be warned...)
>
> The maps show all stars. All stars have planets, or at least some sort
> of solar system.
> Not all of these are easily habitable.
>
> Planets tend to end up in some sort of ecological balance. On the one
> end, this
> might be an industrial wasteland with zero or minimal native life, and
> with heavy
> off-planet support (see below). On the other, it might be a garden
> world with way
> fewer sophonts that current residents of this planet might imagine. EG
> I handwave
> that Earth at near its current technology might be able to handle 1
> billion residents,
> with appropriate support, and with a "nice" ecosphere - wild animals
> still roaming
> around on various continents, in the oceans, and so on. Wipe them out
> and Earth could
> probably handle 50 billion, but of course everyone would be living in
> tower blocks.
> One billion residents, with Imperial-level technology, could make
> Earth into a
> garden world.

Jonathon, let's see how far down that rabbit hole I can go.

Surface area of Terra is 514,718,540.4 sq km.  Assuming land coverage of
30%, _land_ area drops out as 154,415,562.1 sq m - call it 154 million
sq km.

Your 50 billion level (assuming full land use) implies a mean population
density of 323.8 people/sq km.

1 billion people implies a mean density of 6.5 people/sq km - a little
over twice that of STRAYA, deserts, jungles, rainforests and all.

El Wiki (https://en.wikipedia.org/wiki/Brisbane ) quotes Greater
Brisbane, QLD, as managing a mean density of 155 persons/sq km, which
includes parks, green spaces, roads, and lots of single-story
development.  If applied to Terra's land area, that's 24 billion people
on the rock.

The _City of Brisbane_ local government area
(https://en.wikipedia.org/wiki/City_of_Brisbane ) manages 842 persons/sq
km, or 129.6 billion people planetwide.

Looking at the population density in the Macau SAR
(https://en.wikipedia.org/wiki/List_of_countries_and_dependencies_by_population_density
) of 21,600 people/sq km and applying that to just the land area, works
out to 3.3 trillion (3.3E12) people on the rock.

If you start packing people into sky_rakers_ (punching up through the
planetary boundary layer, so at least 1600m tall on Terra, IIRC - all
your BASE jump are belong to us), increase those figures by at least 1
order of magnitude, probably more.

Conversely, packing 50 billion yammerheads in at 10% of Macau densities
frees up 85% of the land area for other use.

>
> So what sort of support would be needed to support this sort of
> population? My answer
> is orbital farms. The food has to come from somewhere, and I have a
> soft spot for the
> "Silent Running" answer.

One option is to nick from starships, especially GT ones with total life
support.  Applied biotech, such as fauxflesh vats, on some floors of
those skyrakers I mentioned.

Skyraker _farms_ might be another idea - vertical farming, taken up past 11.

>
> There are other options: people living off-planet, in orbital
> habitats, arcologies,
> chandeliers, and so on. But still, the food has to come from somewhere...
>
> (Forthcoming: a long post on food, but I digress.)

<snip>

You've definitely knocked some ideas loose in my head.  Thank you.

Alex