Saturday, June 30, 2007

History: Past, Future, and Fake VI

My virtual road trip / work gig continues, but I ended up writing a post on sfconsim-l, commenting on this section of Winch Chung's Atomic Rocket pages. He's already added my commentary there - something wonderfully meta about that - and I'm certainly not above cribbing from myself, so here it is. The subject is colonization waves spreading out from Earth, which leads me to some speculation on SF chronology:

Just glancing though your section there, the key challenge for a lot of purposes is time scale - and oddly, it doesn't have much to do with ship speed; an STL civilization might expand over the long haul nearly as fast as an FTL one.

The key issue - and this comes up in all sorts of contexts - is how long does it take for a planet to go from raw young colony to major world, the kind that could and might send out colonies of its own? This is the basic problem you have to solve for settings in which anyone has a space fleet of their own but Earth.

Let me try to put a few numbers on it.

The threshold for having a space fleet is arguably lower than for colonization, because a planet of 100 million people could probably maintain starships, but probably is not feeling a big population squeeze. To be sure, on some planets the habitable area will be pretty much filled, and even on the more earthlike ones the human presence is getting pervasive, so some impulse to colonize might be developing.

Whether a planet of 10 million people - the equivalent of a single large urban region - could realistically have a diversified enough economy to maintain and operate a fleet of starships seems a bit iffy, unless they are putting a massive effort into it, so massive that it may stunt their other prospects.

The most likely scenario for a world of 10 million people sending out a colony might be that they've decided their current home sux, and they're going to try their shot at another one.

Looking at the other end, how many people for a viable colony. I'd say 10,000 at the low end, with 100,000 seeming a lot more comfortable. That's the population of one semirural county. How many machine shops and such does it have, how much can they specialize for efficiency, and oh yeah, you need raw material, a mining sector and all that.

If you can't make it you have to import it, paying starship freight instead of truck freight, and what have you got for sale? The market for colony-world curios is going to get crowded fast, and if you really do have something to sell, you'll probably need more than a one-county economy to produce it in commercial quantities.

So I would say that you usually have to put 100,000 people onto a colony planet for it to thrive. Colonies with fewer than that can hang on, but if subsidies are cut off they may die off outright, or be stuck in a marginal existence; only lucky ones will overcome it and do okay.

For a colony to really go as a largely self-sufficient postindustrial world it had better have on order of a million people - more or less the equivalent of Bakersfield and environs. I am certain that Australia has a Bakersfield, but I do not know what it is. Maybe our Oz contingent can inform us.

But once again, if they can't make it or pay starship freight for it they do without it, and the equivalent of Bakersfield has a tough challenge producing nearly all the needs of postindustrial civilization. And for exports it is good to have one sizeable airport that can double as the shuttle port and provide steady employment for a lot of the techs.

Big proviso, so hold your pitchforks. This is predicated on the 23rd century, or 28th or whatever, having about the same productive efficiencies of scale that we are used to. If you have got replicators where you shovel dirt in one end and get a washing machine or air car out the other, things are different. But you still need a wide range of human skills, very hard for small communities to provide, maintain, and keep active.

So maybe my figures could all be squeezed down by an order of magnitude, so that a colony of 10,000 is fairly viable, a colony of 100,000 can maintain a full industrial base, and one of a million people can keep its own starships in service. That helps for story settings, but you wouldn't generally expect worlds like that to be active colonizers.

Finally, and most central to time scale, how fast do colony populations grow, either from immigration or birth rate? I would call a million emigrants from Earth each year a benchmark figure for large scale colonization. That's several thousand people each day, one huge ship or several merely big ones, and it still takes a century of sustained effort to plant 100 colonies, each of a mllion people.

From the colony's point of view, people are another expensive import, if you have to pay them to come. If they can afford a ticket and house stake they will only go to desireable colonies. If someone is paying to ship people to you, you may want to know why, because colonies could be a good place to dump dissidents, minor troublemakers, and similar riffraff.

On the export side, I'm more dubious of shipping off refugees, because by definition you're dealing with lots of them, and shipping them all off world is horribly expensive. Much more so than just plucking the town crank and town pickpocket off the streets and getting them to volunteer for emigration.

But by and large you expect that mass colonization involves people who weren't doing so great on Earth, because the supply of nut enthusiasts like people on this board who would actually *like* to colonize is limited, and a million people a year is a lot.

The other side of colonial growth is reproductive growth. Doubling the population each generation is about the historical sustained maximum. That corresponds to 10x per century, so Deseret World might go from 100,000 people to 10 million people in 200 years.

But even doubling per century is a pretty robust population growth rate. That's roughly 1.2x per generation. Unless you're growing 'em in vats, about half the women are having three or four kids, and one way or another the society encourages and accommodates itself to this.

It's no given that postindustrial societies will generally have this population growth rate, though colony worlds may not follow the current trend in industrialized societies toward ZPG or even less.

If colony populations do tend to grow, I suspect the driving force is not the Heinleinian trope of ranchers with half a dozen marriageable - and "husband-high" - daughters, but the pervasive shortage of skilled specialists of all sorts. How this is transmitted to social attitudes I'm not sure, and no doubt can vary widely.

A colony with population doubling each century will go from 100,000 people to 10 million people in about 700 years, pushing us into the second half of the millennium.

Looking at it broadly, say that the age of colonization is around 2250-2350. That is a fairly common time frame for interstellar SF with a geocentric setting; Trek is vaguely in this era, AD2300 of course, and it's implied by some of Heinlein's interstellar stories.

After a century or so colonization from Earth sputters out, because all the low-hanging fruit has been plucked, and it is increasingly costly to reach virgin planets.

Emigration from Earth to the existing colonies can continue after that, but at some point the rate will likely fall. Successful colonies will no longer want people dumped on them, unsuccessful colonies can't absorb them, so emigration falls to the level of people who can pay to go and want to go, or who the colonies are willing to pay for.

So. At some point around 2400, colonization has tapered off and emigration is tapering off. We can guess that there are at least a dozen or so full colony planets - if you can reach any you can probably reach about that many (and you need a good handful for a decent scenario).

The upward limit is about 100 or so true colony worlds, set - regardless of how many worlds are in reach of your FTL - by the postulated size of the colonization wave. A hundred million people, a hundred worlds - an average of about a million immigrants per colony, though the distribution may well be oligarchic by a power law, a handful of colonies getting a large share of total immigrants, growing to populations of up to a few tens of millions, while most have less than a million and kind of struggle along.

Beyond and between the colonies there may be planets never made into self-sustaining colonies, but remaining as outposts, and likely with some permanent populations. If someone pulls the plug on these, though, don't miss the last bus out. Same with space stations and such.

As with the chronology, I think this is a fairly classical scale for a mid-interstellar setting - when there are already established colony worlds, that you can get to by starliner, not just outpost transport or even colonization ship.

There are enough worlds for a diverse interstellar setting, but few enough that people who deal with space, at least, will have some notion of them all as distinct places. (The way "Spain" conveys something to you, or "New Delhi," but "Florianapolis" probably does not.)

A few of these colonies already in 2400 have upwards of 10 million people and some potential to colonize themselves, but these were the immigration magnets, so they probably still feel short-handed if anything, not inclined to send lots of people off.

It will take 200 or 300 years for smaller colonies with rapid population growth rates to start pushing up into the 10 million population range, and might have the impulse and capability to colonize. But it might take closer to 500 years for a substantial number of the original colonies to have much motivation to colonize.

The early goers, though, will have filled in the next layer of easy pickings. Here is where your FTL really matters - whether you can light off freely into the vastness to hunt for a suitable planet, or are constrained by a colonization sphere that is starting to grow again.

But broadly speaking, it seems that secondary colonization couldn't be expected in any serious way until sometime well after 2500, and perhaps not in a big way till sometime around 2700-3000.


Anonymous said...

Hi Rick
I followed the link here from the Atomic Rockets main page & have since realized you are the same Rick who posts quite often on the Compuserve History Forum. I think I will have comments on some of your earlier posts, eventually.

Does Rocketpunk allow for O'Neill type space habitats? If so that changes the picture quite drastically. My own belief is that if there is to be any significant off earth population, the vast majority of humanity will be living in O'Neill type habitats rather than on planets. If such habitats work, there is enough material available to make at least thousands of times the surface area of the earth, leading to solar system populations in the trillions. Given the modest birthrates in post-industrial populations it will take a while for population pressure to become a motivation for interstellar colonization.

One motivation that would work earlier is curiosity. If telescopes identify an extrasolar planet with life, eg: by detecting O2 & CH4 in it's atmosphere, then people might want to set up a self-sufficient colony in that solar system to study it.

BTW the least implausible schemes I've heard for interstellar travel involve some sort of beamed propulsion. This suggest the way to set up a colony would be to have one propulsion beamer to send a continuous series of small vessels. Each vessel carrying a few tons of useful equipment or a few colonists in suspended animation. If the acceleration is limited to about 1 gee then the beam would accelerate each vessel for a month or 2 to get it a bit over 1/10 c, before starting on the next vessel.

Kedamono said...

Rick wrote:

You know, when I went to Winchell's page and ran the numbers for our local bit of space, out to 15 light years, I got a different number than what I got from another source.

His equation for total number of starts is:


But gives us about 33.75 stars within 15 light year radius of Earth, Looking at an actual source, that number is around 53 stars give or take a couple. So his equation should be:


I'll take it as read that his Habcat based equation is accurate based on that data.

One reason is that I write stuff for a RPG, Tri Tac's FTL:2448. The known space portion of FTL:2448 is about 75 light years in diameter. Using real star data, we've mapped out 85 light years. But those edge sectors are mighty sparse, so having a method to fill those sectors with stars is very necessary. Having an accurate potential number of stars for those sectors important. (The actual sector is a hexagon 31 wide and 41 tall.) Doing a volume calculation for that is a little bit of a challenge but I have my resources to work with.


Sorry Doug, O'Neil colonies are not part of the Rocketpunk oeuvre. Wagon wheel space stations and domed cities on the moon is.

And technically, life on other planets, sentient life. Mars has Martians, and Ganymede has Ganymedians.

Rick said...

Jim - yes, that's me. I've been meaning to flog my blog over at Histforum, but there hasn't been any traffic lately in the sections where I hang out. I guess I should really just drop by to say "Drop by!"

What Kedamono said about O'Neill cans. They came into vogue around 1970, IIRC; the rocketpunk source era ends just about when actual space travel begins.

But mileages differ - for example, my own take would not be to use a retro Solar System (dying desert civilization on Mars, for example), but accept it as we now know it. In source terms this is more ClarkeVerse than HeinleinVerse, but Heinlein's Solar System was old fashioned even in the 50s.

You could probably get away with habs in a rocketpunk setting so long as you don't call them that - just call them space stations, and hint that they grew by accretion.

But truth to be told, I'm doubtful of large off-earth populations until you have either a nearly Clarkean indistinguishable-from-magic techlevel or convenient interstellar travel (which is also magic).

It is inherently more expensive to sustain humans in space, because you have to supply things habitable planets give you for free, like air that won't leak away. Even at the high end of foreseeable tech it will be perhaps an order of magnitude more expensive to keep people in space than to keep them in Antarctica.

So barring easy access to habitable planets, about the most I really see in space, in terms of population, is bases and maybe the equivalent of university towns.

Beamed power is indeed looking credible for interstellar flight, but getting anywhere near c still requires truly staggering amounts of energy, while anything much less means multi-century travel times.

kedamono - the discrepancy on Winch's page may be a distinction between stars and stellar systems - 34 stellar systems with a total of 53 stars sounds about right, roughly half of systems binary, with a couple of triple stars thrown in.

For filling in space on a map I would want to use the figure for stellar systems, then roll for binaries and such. The general thinking seems to be that binarity usually disrupts any planetary system, but very close binaries can have planets circling both components, and very distant binaries can each have an undisrupted planetary system.

Nyrath said...

Well, in the HabCat database, it listed 993 stars within 15.3 parsecs (50 light years). After fiddling with my slide rule for a while I came up with Ns=Rly^3*0.01

You can check my math here:
(scroll to the bottom)
...since I have been known to make amateurish mistakes in arithmetic.

Kedamono said...

Rick and Winchell:
I didn't mean to be a bother. I meant to say 53 stellar systems, not stars. If it was stars, it would be around 70 or so stars.

The problem with a larger survey, is that the dimmer stars may not have been spotted, so that the numbers are artificially low the farther you get out. Like how many Type K and Type M stars are neighbors of Agol? As far as I know, we don't know, or we just recently found out.

And even the start chart I'm looking at isn't up to date, it's missing about four or five brown dwarves that were recently found in our neighborhood.

Nyrath said...

Kedamono, I understand. What I didn't make clear is that I am not a real live astronomer. So I used the HabCat database (which was based on the Hipparchos database) since it was convenient.

If you've got better figures, by all means make your own estimates of star density.

You might consider getting in touch with some astronomers to get some information straight from the horses mouth. I'm sure somebody has tried to make estimates of the density of various spectral classes of stars.

Kedamono said...

Winchell, don't take my ham handed comments as a diatribe or criticism, (Well OK, maybe a little criticism) or all the work you've done on your Atomic Rockets page. You're an inspiration to all of us closet SF writers and game designers.

So enough fawning, and back to the subject at hand.

The topic about colonization is one that I'm and other writers for Tri Tac Games will have to address for the RPG game FTL:2448. There are over a hundred colonized and homeworlds for us to define and we don't have much to go on. There are only four that are detailed in any appreciable amount: Earth, the world Brycinon, and the two of three Fomalhaut colonies: Alverez Station and America. The third, Dorsey, is only mentioned in a catalog.

So, I created a detailed write up of the colony world of New America, which was described as a collection of Human Amish and Mongols, with two alien cultures settling there as well:

New America

To do this, I had to find population growth equations and adapted them for the alien races.

Rick said...

kedamono & winchell - Getting a full census of the solar neighborhood - and thus a reliable figure for star distribution and density - is going to be a moving target for a long time to come, because previously undetected faint ones are always being added. And as you increase radius from Earth, the "previously undetected faint ones" grow progressively brighter.

I have additional comments on this problem, but I think I'll promote them to the front page.

Anonymous said...

But truth to be told, I'm doubtful of large off-earth populations until you have either a nearly Clarkean indistinguishable-from-magic techlevel or convenient interstellar travel (which is also magic).

It is inherently more expensive to sustain humans in space, because you have to supply things habitable planets give you for free, like air that won't leak away. Even at the high end of foreseeable tech it will be perhaps an order of magnitude more expensive to keep people in space than to keep them in Antarctica.

I really can't agree with this Rick, since I don't think that life support requirements are nearly as big a problemn a orbital access requirements. Earth orbit has been described as "Half way to Everywhere". Once you've got a peerson up there bringing them home and sending another person to take their place seems a bit wasteful. Once you've constructed a functioning habitat and gotten people to work up there a breeding population is more economical than constant turnover of the workforce. This can occur even if people originally intended to be short-term labour and then later change their plans.

The problem is that most of the costs in setting up a base are incurred right at the start. Building a hull of the necessary size, plus making sure the structure can be expanded if necessary, power-generation, biological material like the algae for life support, and bringing in the workforce are the major expenses. Once that's done and the base is functioning the costs drop off dramatically.

This is particularly true when you consider that a functioning space infrastructure can cut costs dramatically. Metal can be brought in from the Moon, Asteroids, and a number of other places with much less gravity to contend with than Earth. Volatiles are a bit rare in the inner system but are muuch more common in the outer system, the relative cost will determine the most economically viable option. Once you have a source of volatiles and extra life-support capacity you can convert plant-matter into petrochemicals via thermogenensis. Ergo we have plastics and polymers, along with metal. Throw in the supply of materials, and potentially energy as well, back to the Homeworld and you have a justification for continuing to send those who want to leave, or those who are wanted gone, up the gravity well to supply more workers and genetic material. And at a certain point the economics of scale start to kick in a prices start to drop.

Now the initial cash required is a simply massive amount. That being said once you start establishing actual infrastructure in space the cost of subsequent activity will likely not be as severe. Now, how the corporation or governemnt putting out the initial funds plans to benefit from this arrangement is...well that's getting into social dynamics and may potentially lead to story seeds. It's the 4th of July today; taxation issues anyone?

R. Mildred said...

Whether a planet of 10 million people - the equivalent of a single large urban region - could realistically have a diversified enough economy to maintain and operate a fleet of starships seems a bit iffy

Meh, add robots and beanstalks (which are easier to drop onto planets than to create from within a gravity well) and you don't need a large population base to run a large space industry, and then it's just a matter of whether they use birth control or eugenics policies that might in some way artifically limit population growth.

but the biggest problem becomes justifying the creation of such things in the first place, the smaller the population you throw out to otehr stars, despite being able to create large space economies with ridiculously small population bases, is why would anyone waste there money doing it in the first place? Large populations justify themselves, and you can handwave about how humans are the cheapest and most dependable form of self replicating robot, and then you can add McGuffinite to justify the expense (because mcguffinite always costs exactly enough for wahtever you need it for, like how all rocketships ultimately travel at the speed of plot).

And then you fast forward a few decades until the McGuffinite mining colonies go independent, and so they need new colonies to replcae them, which go independent, which...

Once you have two colonies, it's very easy to justify three, and then four, and hten a galaxy of the things.

Rick said...

Doug - Life support is nothing like the dreadful barrier that orbit lift is. Still, habitable planets, e.g. Earth, have a big competitive advantage as human habitats. Free Air !!! Cheap Water !!!

The costs of habitats don't end when they're built, because there is operation and maintenance of a lot of fancy plumbing - plumbing that never needs a plumber is beyond handwavium.

This makes the (foreseeable future) cost of living in space inherently a lot more expensive than living on Earth. Which won't keep it from happening, but severely limits how much space habitats can grow.

As a comparison there's been no significant development of people living under the sea, though it's technically possible now, and surely cheaper than living in space.

A standard SF trope is developing space resources to save on the horrendous lift cost. But there's a subtle inconsistancy, best summarized by Cobb's Law: If orbit lift is cheap, you can haul up the stuff you need. If orbit lift is expensive, you aren't up there either.

If you have cheap enough orbit lift to build a "real" space station, with several hundred people, it will likely be cheaper to haul up what you need, provided by an established industrial base, than to set up a whole new infrastructure. It will take a long time for space industries to out-compete Earth industries, given orbit lift cheap enough to allow the cool stuff at all.

Rick said...

R Mildred - I'm conservative about space economics; I don't see space travel as being cheap this side of serious magitech.

My basic way of thinking about it is this: A starship, as usually pictured in SF, is a piece of hardware about as fancy and complicated for a future century to build as a jet airliner is for us. Other things equal, that should make the real cost of a ticket - relative to the passenger's income, the basic measure - about the same.

But other things aren't equal. At the speed of plot - thank you for the first classic line on this blog! - it usually takes a starship a few weeks to get anywhere. This is for good reason: Relatively long travel time is exactly what makes the setting feel bigger than our crowded anywhere-in-a-day world.

But this means that Starships have lousy productivity. A jetliner can deliver a full load of paying intercontinental passengers every day; a starship may take a month to deliver one passenger load, meaning the spacefare has to be about 30x airfare. Make it 100x for a roomette, because you do not want to live a month in an airline coach seat.

But your real point, as I read it, is that small populations remain outposts, while big populations become societies standing on their own. That's a really important point. Anyone writing space colony settings in the next few hundred years struggles with small colonies that just can't be big players.

Large populations will take time, though - even if you grow babies in vats, someone has to potty train the little bastards and teach 'em a little rudimentary tensor calculus, in order to make useful citizens out of them.

Completely off topic, but I dropped by your profile: If you were a pirate, how would you avoid laughing when saying "poop deck"?

I can assure you - as someone whose novel includes 16th century ships - that there's a serious problem of nomenclature regarding the highest deck abaft. All the more because it's an important deck, the functional equivalent of the bridge.

(This is one reason I hate "bridge" for a starship control room. Naval ships still have a quarterdeck, but it is NOT the underway control station.)

The 18th century has it easy; by then it's the quarterdeck. But in the 16th? "Captain to the poop!" "If the boarders take her poop, she is lost."

Well, the language marches on, and writers must accommodate. Only a few years ago, pirates could raid a town for plunder, loot, or booty. Nowadays well-disciplined pirates, at least, only take booty in liberty ports.

Anonymous said...

I'm not convinced that living in a rotating space habitat *has* to be enormously more expensive than living on a planet. However, getting the costs down requires some economies of scale.

In particular, if the space habitat is much more than a km in radius it can have weather & it shouldn't be hard to set things up so late afternoon rain falls on the agricultural areas, so no irrigation piping is required. There are still a lot mirrors & windows as well as plumbing for for the residences, but the O2 & CO2 are carried between people & plants by 'natural' air currents.

I don't see that the maintenance need be orders of magnitude harder than for the plumbing that keeps the farms & cities of the US SW viable, or the maintenance of the dikes that keep the Netherlands dry.

There is still the issue of what economic motive there might be to get space settlement started.

One bit of McGuffinite that's had a lot of attention is the Solar Power Satellite. Unfortunately it seems that even with zero launch costs the size of the transmitting & receiving antennas would make the costs uncompetitive. Also new technology that would allow more concentrated power beams, would make those beams possible weapons, which would likely create too much opposition for them to be allowed.

I can thing of 2 other possibilities.

1) Some very useful items that can only be made in zero gee. Also once there is *some* space based industry, items that need high vacuum for manufacture would be an additional income stream.

2) Space based mining, but this will be sent to earth for only a very limited class of materials. Siderophile elements
are those which tend to mix with metallic iron rather than rock, & so in the Earth are mainly in the core, where they are hard to get at. Some asteroids also developed a metallic core with relatively high concentrations of those elements & the iron-nickel meteorites are fragments of such asteroidal cores. The important point is that the siderophile elements include such valued elements as platinum.

As well as asteroid mining it might also be possible to use magnets to extract grains of metallic meteorite from lunar regolith.

Another thing worth noting is that it shouldn't be difficult to make heat shields for atmospheric entry from the slag from lunar or asteroidal mining, so sending the products of space mines or zero gee factories to earth would be cheap even with current technology.

Anonymous said...

Cobb's law strikes me as a case of a false dichotomy, because it ignores the possibility of moderate progress. There will either be sufficient demand and advancements to make space-based development feasible, or there will not be and we will stay on this planet permanently. But without several major breakthroughs in both orbital access and engine technologies beyond those necessary to set uo space-based enterprises to allow for the shipping of all your supplies and workers into orbit every time it's time to go back to work. Given the length of time necessary to reach say, the orbit of Uranus, how much Delta-V does it take to make setting up a permanent community for the Helium-3 miners out there an unnecessary expense? That's an extreme case, but the principle is still valid in the inner system. And ultimately the cost of living in Space is meaningless without reference to another factor, the economic value of space-based industry relative to the Terrestrial variety.

What I think is more likely is that increasing resource and energy issues on Earth are going to make Space industry look potentially profitable long before contragravity or other real cost savers on orbital access come along. As such early Space industrial and resource extraction communities will be at least semi-permanent, with minimal turnover from people going back home to Earth. Now granted the communities will still be small, since much of the work will be minding, maintaining and repairing robots. However when you include the necessary personnel to maintain life-support and do all the other tasks needed to keep the place running you have the start of a small colony. Maybe not 100,000 and maybe not even 10,000, but enough people to form a community. There have been settlements that started with less than a hundred people; if the economics pan out they will grow rapidly but a colony doesn't need to start off big provided there is a flow of fresh genetic material to prevent inbreeding and a flow of fresh building materials to provide living space. And if Helium-3 mining becomes the new gold rush than other people are going to be shipping material from the asteroid belt or Luna or Mars to provide material in exchange for cash.

Now some later advances (like anti-gravity or space elevators) might make those communities irrelevent, but what else is new? It's not like groups of people being victimized by economic obscelescence is anything unheard of. The thought of dead hulks of space stations littering the solar system after their populations rushed off to settle the new worlds found through the wormholes is worth considering.

On the subject of colonizing already habitable worlds, I have to say I'm rather troubled by the idea. Even setting foot on another world with a functioning ecosystem can lead to unforeseen consequences, not the least of which is the spread of microbes. We may find a new plague on some rock out there, but by the same token we may also be potentially causing catastrophes just by setting foot on another life-bearing world. Now combine that with actual settlement and the forced displacement or destruction of the local ecosystem and we have some major problems on our hands.

The obvious way around this is terraforming of otherwise lifeless worlds. The thing is a lot of the stories surrounding terraforming I've read touched on the possibility of terraforming worlds that have life on them, but are still disagreeable to human settlement; presumably this is kess hard work than picking a world that is lifeless. I have to wonder if living in artificial habitats is the only honourable choice open to us short of managing to terraform a lifeless rock. As for those who are willing to risk plague and destroy unique life all I have to say is this: Long live the Restorian Order and the United Wildworlders!

Now can anyone here catch either of those references?

Rick said...

Jim & Doug - abbreviated reply, since I'll be blogging a lot more about all this.

Big enough hab structures will generate internal weather, with great potential operating and maintenance simplification. Complication is that we don't know how big you need to get a functioning water cycle. The largest terrestrial buildings have some internal weather, but that just touches the extreme lower threshold.

I suspect that habs big enough for weather to do the heavy lifting will be very big indeed, and therefore humongously expensive to build. I'm also uneasy with the safety of single huge pressure vessels.

What could bootstrap us into space deserves a LOT of discussion ...

Anonymous said...

I reread your post I had some further thoughts.

Your picture is of a nearby sphere of colonies developing & then there being a long pause before the 1st colonies develop to the point of being able to set up colonies of their own. This seems to me to depend on what tech is assumed for FTL travel.

"wormholes" are one of the least implausible FTL methods & if it's feasible to make wormholes a different scenario arises.

You make a wormhole pair & send one end off to a nearby star @ STL speeds. Once it's there you have instant transport between sol & Alpha Centauri. Keep sending out the wormholes & the sphere of colonization expands at eg: 1/10 c with no pauses for development.

Anonymous said...

OK Doug does:

"Long live the Restorian Order and the United Wildworlders!"

Have something to do with the proposal to introduce elephants to N. America as a replacement for the mammoths that went extinct?

Rick said...

Doug - colonizing lifebearing planets may indeed be very problematical. Alas, terraforming lifeless ones is likely to be a very slow process, making even STL travel look fast by comparison.

Jim - The bootstrapping problem is the biggest of them all. I think space is inherently expensive at our tech level (or even well above it), but surely far less so if it's being done on an industrial scale.

It is also an odd annoyance that our tech progress has tended to squeeze humans out. After all, there already is a big, profitable space industry, comsats (and geosats, etc.)

In the rocketpunk era the assumption was that a crewed comm station would be required, thus shuttles to serve it, operating on a routine basis - just the groundwork (skywork?) you'd need for pushing on to the moon and planets. And all paid for by TV and telephone execs dreaming of nothing but profits.

Instead it has turned out cheaper to send up a replaceable satellite on an expendable booster. I suspect that even space mining would be largely robotic, perhaps entirely so.

My colonization model does assume that FTL has some time lag - either from a finite pseudo-speed, or from multiple jumps - so that there's some distance from Earth at which direct colonization is impractical. Whereas colonization from an intermediate planet would be practical, but only when the planet has grown to the point of sending out daughter colonies.

If FTL allows you to go anywhere to anywhere with similar time/cost involved, then my consideration doesn't apply, and you wouldn't get a situation where direct colonization from Earth ceased because it was already surrounded by established colonies.

Anonymous said...

I guess the one of the big questions of Science Fiction is "Have we Learned anything?" A number of writers have written about Alien Contact scenarios where there is some question of whether or not a species is sentient, but the decision to colonize is never really questioned. Without getting into the wacky fringe of the Deep Ecology movement and "Better dead than contaminated" thinking I think there is a case for avoiding any world with multicellular life present.

Star Trek's Prime Directive manages to completely miss the point in this regard. For starters They ignore the very real threat of biological contamination, to the point of intermingling bodily fluids, in favour of worrying about the more nebulous threat of cultural contamination. Secondly trhe issue frequently gets brought up when non-intevention could result in extinction, which neatly stacks the deck against the regs on general principle.

As for the two groups I mentioned:
The Restorian Order were a group of villians on the show Andromeda. Their methodology for combatting ecological irrespinsibility varied between conventional terrorism, commando activities, and most prominently ship-based piracy. There villianous status mostly resolcved around them being indescriminate abpout that last bit.

The United Wildworlders were a group combatting the terraforming of worlds that had pre-existing ecosystems through monkeywrenching activities from the Fading Suns RPG setting, from the time of the Second Republic. They did not end well, after getting shot up by the local rent-a-goons they fled into the jungle, had an encounter with a very odd form of alien life, and the result was the genesis of the symbiot culture.

The Restorians in particular were portrayed as villainous, and there is certain tendancy towards such groups. David Weber created a group referred toi as the saints for his "March to the [Blank]" books. However when you move away from the fringe that supplies your villains I think there is still a fairly rational argument against simply obliterating local ecosystems on the grounds that nothing sentient is living there. And in a state of neomedievalism, where non-state actors may even have their own fleets, a more modeate version of a group like the Restorians could have some potential.

I'm going canoing, I'll be back next week.

Anonymous said...

Very valuable piece

Canageek said...

You miss one reason for space mining in this discussion: A lack of an irriplacible resource. Helium is the only thing we can use for good superconductors, and we are running out. Suppose that we can't find liquid nitrogen temperature super conductors, but our technology becomes more and more superconductor dependent. Suddenly helium mining on the gas giants looks a lot more reasonable, even if it is crazily expensive and somewhat dangerous.

Rick said...

Interesting point - but was this comment meant for a different post? This one is about interstellar colonization, and doesn't really address solar system space mining one way or the other.

On the point, I suspect it would be easier to get helium from icy outer moons - or even Kuiper Belt objects - rather than screw around with gas giant atmospheres and gravity wells.

And I wouldn't be surprised if the whole process were automated - it is probably cheaper to lose a fair fraction of automated plants than to send people to keep them in better repair.

Canageek said...

There were a number of comments on mining as a route to colonization. I find it interesting that military ships require far larger crews then civilian ships, as people are more flexible then machines, and under harsh conditions and in combat it is easier to keep simple machines and an operator alive then it is to keep a highly automated system running.

I'm tired and not sure I'm making sense, but if this remains true (and it seems likely) that could give justification for colonization: Support staff for robotic mining operations.