# poly: Solar system development

From: Damien R. Sullivan <phoenix@ugcs.caltech.edu>
Date: Thu Dec 11 1997 - 11:51:20 PST

To ratchet the eschatology down a few orders of magnitude...

I tried out on some friends the idea that the solar system will probably
be fully developed in 5000 years. The responses I got were "that's not
realistic" and "why would we want to grow that fast?". As I'd already
mentioned my parameters, and as even the most developed countries today
get worried if they grow less than 2% a year, I didn't know what to say.

The calculation itself is simple. Assume that the total economy can
maintain a doubling rate of once a century (annual rate a stunning 0.7%)
I figure this is low enough to avoid pollution or transportation
problems. Then 5000 years == 50 generations < 10^15 growth. World
civilization now uses a few terawatts (not counting the benefits we get
from ecological energy use) which gives power use then of at least 10^27
watts. 5 billion people times 200 kilograms per person (minimal limit)
gives 10^12 kilograms mobilized by humans now, or 10^27 kg then. So the
simple result is that we would be using the mass of Jupiter and a few
times the energy of the Sun in 5 millennia. The real point is not
whether we'll have disassembled Jupiter or Dysoned the Sun or not, but
that saturation is quite easy to achieve.

This result is more relevant in discussions of science fiction, as I
feel it shows that almost all SF which takes place more than a few
centuries from now suffers from severe lack of imagination. Not that
this is any great surprise.

More sophisticated calculations: at First World growth of 3% saturation
occurs in 1250 years. But the First World may already be a saturated
economy; properly developing economies currently grow at around 10%. 3%
is the maximum population growth humans can sustain, I think (just in
terms of breeding) but if the amount controlled by each person grows by
3% then such a fast economic growth might be sustainable over a long
term.

I tried finding on the web population statistics for colonial America,
the California gold rush, or Australia, i.e. what growth driven by
frontier exploitation rather than technological advancement might be;
the best I found easily was Australia more than doubling each decade
between 1825 and 1861; presumably that was in large part immigration,
however.

10% growth puts Jupiter-saturation at most 350 years away, which I'm not
sure I believe. Of course AI-type advances affect what's possible.
Minds can be copied, so reproduction doesn't take 20 years; and fast
minds could speed up technology. But I'm looking for the lower end of
conservative predictions. Too many new assumptions label the crackpot,
in popular debate.

At this point I start thinking about the form of development. If people
like to stick themselves onto existing rocks I can see an explosive
development of the available surface area which rapidly levels off,
especially if settlements don't like to turn inside-out the rock they're
living on. I don't think the terrestrial surface area of the system
amounts to ten times that of Earth, so saturation could occur within 100
years of a decent expansion into space, at 2.5% growth. Here
saturation implies colonies covering the Moon, Mercury, Venus, Mars, the
asteroids, etc. If species in general behave this way it could explain
why the universe isn't dimmed; local pressures favor short-term
development which inhibits more thorough development later. Couple
this with a high risk in fast interstellar travel and the Fermi paradox
gets a new shot of life, if not a large one.

If people, or an HPLD, favor settlement in wholly artificial habitats,
then I think rapid strip-mining of any available occurs. As you'd want
to avoid gravity wells at first, a time-lapse view of the solar system
would show the asteroids, and then the planets, evaporating into the
mist of a diffuse Dyson sphere. A proper time estimate for this would
use differential equations, or a simulation, which is more work than I
feel the issue is worth just now, except for programming practice.

-xx- GSV The Low Golden Willow X-)

We are animals who are becoming gods. We should expect some of our
higher accomplishments to shock our lower selves. But we should not let
shock decide our lives or policies.
Received on Thu Dec 11 19:44:42 1997

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