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Gzg-l@lists.csua.berkeley.edu
http://lists.csua.berkeley.edu/mailman/listinfo/gzg-lHi..
I'm try to figure out populations for my non-canon power.. I know Beth
has
some workable system for figuring "population" #. But looking back
thur the archives, I didn't find it.
But if anyone else has a workable # system please share.
DOCAGREN
Just a Lurker here on the Digest, But maybe I have a good idea or 2..
:-)
> I'm try to figure out populations for my non-canon power.. I know Beth
The (extrememly crude) method I used:
Make up whatever your immigration is going to be, accounting for "number of
people per ship x number of ships" and how attractive your planet is.
Alarish is a high-tech libertarian paradise, which makes up for the lack
of air. Cibola is "just like home, but not crowded" if you're from certain
parts of India or Africa. To get a plausible maximum, look at how many people
were immigrating to the US during, say, the Potato Famine. Picking a number
entirely out of the air, let's say 40,000 per year.
Figure out what a maximum population growth rate will be, ie how many
babies. This will be lower than you might expect--let's say 3% per year,
which is pretty high, as I recall.
So you have Year2Pop = Year1Pop * 1.03 + 40,000, and cycle that for as
many years as you wish.
I also flexed both the immigration and the birth rate, eg immigration went up
whenever there was a war from which I might get refugees.
I think the point is, it's gonna all be crude, short of having the
sophisticated software I believe Beth mentioned in her posts.
However, back in 2002:
***
> I'd love to see how you've got them set up, if that's possible.
I can probably draw together some documentation on it all, which would show
you how to write a fairly good analogy using simpler code, you could even do
it in excel (though a proper crack at it may involve a few worksheets, macros
and some of the extra utilities).
Just let me know.
***
I don't think anybody ever asked her for her pointers; might be just the thing
for her to put on the Fulton website, if she ever gets the chance.
;->=
I've been Google-ing, and peeking into some Sci-Fi writing references,
but haven't found any fairly good suggestions on how to do the modelling of
interstellar growth. Most just deal with a single planet after 'seeding'.
If anyone else does know of such a site/book, by all means pipe up.
And, Mr Ariander's right about the formatting. I can't guarentee mine is
clean, but I'm pretty sure it doesn't come in those REALLY difficult to read
colors. I've been wrong before...
The_Beast
Chris answered DOCAgren when he wrote on 05/06/2006 06:42:45 AM:
> > I'm try to figure out populations for my non-canon
*snippage*
G'day,
You don't want to have to grapple with the models I use in my job, but I do
have some stuff I'm happy to hand out.
You can do very simple population dynamics modelling in a single sheet
in excel (which I can give you) - it takes into account migration, birth
rates, mortality social welfare system type (which governs how the
population reacts as it approaches carrying capacity - or the total
amount the currently available resources can support).
If you're willing to go multiple sheets then I can also give you a matrix
population model I use to teach a class here. It has explicit age and sex
structure so that you can see the problems of aging populations, imbalanced
sex ratios and can also explicitly see what work force you've got to draw from
for you military etc.
At some point in the future (probably towards the end of the year) I'm
going to write a simple c++ metapopulation exe (so for our purposes the
migrants get tracked, at present most space colony models assume that migrants
are there for the having without checking the numbers add up and we're not
assuming an infinite migrant pool) which I was going to give my class and the
10 Worlds (Attack Vector) folks.
As to population viability, which is what I think you're talking about you
want a few hundred thousand at least and reasonably high human growth rates
(3% birth rate is high for humans, we're more typically about 2%). Less than
that (and especially less than a few thousand) then you'll get into the realm
of genetic bottlenecks (which aren't immediately catastrophic, Iceland for
instance didn't go belly up, but does leave you open to an epidemic
overwhelming the population) and biased catastrophic mortality effects (where
a catastrophe takes out your entire breeding base etc).
The exe files can get quite large so it may be best if I posted them on my ftp
site. I can't do that from home, but will do it early in the week and let you
know.
Ultimately though unless you really want to have the fun of playing with the
models Laserlight's plausible story telling approach is fine, just keep in
mind whats plausible given the colony size you're after;)
Cheers
G'day,
> I can probably draw together some documentation on it all....
If you're willing to wade through the text a good introductory level undergrad
Uni course is up at
http://www.ento.vt.edu/~sharov/PopEcol/popecol.html
While reading through the lot may help understanding you want lectures
5-7 in particular. The excel spreadsheets I use are quite similar to
these kind of simple models, though they have some added twists based on extra
info I have on what does and doesn't work for avoiding math artefacts.
I don't know if the beast had some of the extra NASA comments on artifical
habitat issues in mind too, must admit I tend to abstract those away as
differential mortality and reproduction rates as the colony develops (that way
you can play with what ever feedbacks or colony success rates that you want).
Cheers
I don't recall; did you include further emigration to the colonies? I was
thinking that might enter into your work as well.
Thanks for the link; 'If you're willing to wade' definitely translates into
wade, as a child's first tentative toe-touch into strange and chilling
waters. ;->=
The_Beast
Beth wrote on 05/06/2006 06:51:31 PM:
> I don't know if the beast had some of the extra NASA comments on
G'day,
> I don't recall; did you include further emigration to the colonies?
Unless the time line said otherwise I did allow on going migration (both to
and from the colonies, but the to tended to out weigh the from).
> Thanks for the link; 'If you're willing to wade' definitely translates
Let me know if I can do anything to make the going easier;)
Cheers
G'day guys,
A long time ago in a galaxy far far away I pormised to put up some simple
population spreadsheet models. Now finally up (and hopefully helpfully colour
coded and note paged).
ftp://ftp.marine.csiro.au/pub/fulton/simple_population_models.zip
At some point I will get more sophisticated ones up there with metapopulation
cycling etc, but for now there should be more than enough for simple empire
building (while the kind of resource management advice
I do uses far more sophisticated models day-to-day, in mainstream
ecology many science studies on population dynamics wouldn't get too much
beyond these so overall you should be fine).
If you have any questions don't hesitate to yell at me;)
> On Sat, Jul 29, 2006 at 07:07:11PM +1000, Beth.Fulton@csiro.au wrote:
> ftp://ftp.marine.csiro.au/pub/fulton/simple_population_models.zip
Distinctly interesting - many thanks!
R