Building an Arcology

[Gnusam Netor]

Originally posted by Fritz88:
Well, yeah, "old-school" farming will be right out - unless you want a planet, and not an arcology.

So suddenly old-school isnogood ehh?

Old-school is cheap(er).

edit 1:
And pays better then your icky hydroponic plasti-meat.

edit 2:
Hurry up with the responses fritz & robject, i have to goto work in 4 hours... (and sleep some too)

 

[robject]

Old school (at least in a sealed environment) might be more expensive in terms of maintenance. I might handwave and say maintenance cost is invariant. But I think all those domes and vast volumes would be prettier.

...and real beef certainly tastes better than Soylent Blue.

Hmmm, interesting. Low-tech arcologies suddenly become luxury food producers and posh resorts, while high-tech arcologies become crowded business centers and mining transfer stations?

 

[Scott Martin]

So here goes with the big nasty math. These numbers put "Netherlands" density in the ballpark of 65 kDtons per perrson, mostly because you are worried about *area* not volume available per person. This gives you "old school agriculture" cows, pigs, elephants, whatever you really want to chow down on.

Orbital Archology "Foundation"

Base hull: 2 KM diameter by 15 Km length. Minimum thickness by FF&S is ~4 CM steel, braced for 1 G.
Base (spun) hull area = a hair over 94 square kilometers
volume is roughly 4.7x10&sup1&sup1 meters&sup3, AKA 3.37 GIGA-tons displacement
required hull thickness + and structural members is a bit under 4 million cubic meters of steel (but only 6 GCr)

Assuming that the total mass of the asteroids is around 2.3 x 10&sup2&sup1 kg
http://nssdc.gsfc.nasa.gov/planetary/factsheet/asteroidfact.html
If you want to look for "resources" insystem, try here:
http://nssdc.gsfc.nasa.gov/planetary/planetfact.html

if 0.1% of the asteroids is suitable for building hulls from, the asteroid belt can produce just shy of 75 million of these orbital habitats. That would give an aggregate surface area of 7 billion kilometers for habitation, all of it "prime" real estate. And that's Just the asteroids (Ceres is about 1/3 of the total mass, so smelting Ceres gives over 2 billion square kilometers of area) Phobos would give "only" anothe few million square kilometers, but there are lots of "rubble" bodies floating around without cracking GG moons...

A "distopian" environment (algae vats, soylent green and minimum volume/person + 10%) gives a population of almost 1/2 BILLION sophonts per platform (and would probably need Grav plates)

A platform at the other end of the spectrum (max long-term life support size + 100% per person) gives a population of 15.6 million per platform.

These two are based on FF&S-2 numbers. The following is just extrapolating the hull area and putting people in it: that's 1 km of "waste cieling" per person, so this is likely to be what you should expect for an "agricultural" archology: 3 "towns" of 15,000 people each.

"Garden World" platform (population density = Netherlands, at 466.45 persons per square kilometer) gives a population of just under 45,000 per platform.

Cost for the steel hull is less than 3.5 billion. I get issues with the life suport rules (especially the cost and power) but this is probably because they aren't intendeed to be used this way... I'll probably look at some FF&S ships and look at a compromise solution: Extended life support would take more surface area in solar panels than this hull could carry, which is a lot of expense, especially considering the "atmosphere scrubbers" in use would tend to be things like Alfalfa...

Scott Martin

 

[Gnusam Netor]

Originally posted by robject:

Hmmm, interesting. Low-tech arcologies suddenly become luxury food producers and posh resorts, while high-tech arcologies become crowded business centers and mining transfer stations?

I think so, difficult and/or work intensive seems to be more expensive on earth anyway, even when equaly nutrient(?) consumables exist.

(low-quality)cow-meat cost 4-5$/kg in sweden, Moose-meat cost IIRC 15$/kg.

As for posh resorts... (now thats a something

)
real trees and real rabbits for a astroid-miner must be heaven (but you don't actually have to visit that dirty garden world in the next system)

 

[robject]

"Hunt real wild rabbits! Walk among real trees!"


Mr. Martin, your "old school" numbers look like a huge ratio of volume per person. Even I have caved in to peer pressure and reduced my TL7 requirements from an originally huge number down to 2000 dtons per person... 65kdt/person is large... (but then, if the cost is low, who cares?)... but if you put a tiny maneuver drive on it, volume(mass) may once again become important.

 

[Scott Martin]

Using FF&S type systems, the real "costs" are in the "basic" life support: recycling the air and water. (and the power to drive same)

I suspect that the "shipboard" systems would be optimized to conserve volume, with a correlated trade-off with expense and power consumption. If you're willing to allocate 1 million cubic meters per sophont (or even in the thousands, the area where robject and fritz seem to be comprimising) then the power and cost aspects probably fall considerably.

I think that we may be talking about two different things: Are you looking to build your "planet in space" (my model) or just "Self suporting silos" where you can produce / recycle enough food, water and air to keep the population alive.

"silos" give you the "distopian" option in my proposal, but I really wouldn't have any interest in living in even the "nice" version of that proposal (with a "massive" 3,000 m&sup3 per person) if you are going for "Silos" build them on a body with gravity and save yourself the cost (power and $$) of the grav generators: there is no need to make them orbital, since you can just keep building "up" to 50+ kilometers.

Scott Martin

 

[robject]

Let's see how 2^(18-TL) translates to a semi-real world.

TL7: 2000 dtons/person: real woods and wildlife + vegetable farming

TL8: 1000 dtons/person: same as above, with fewer woods and wildlife.

TL9: 500 dtons/person: a cultivated grove in tandem with a high-value farm, vertical gardens, algae vats. Caged critters.

TL10: 250 dtons/person: small citrus grove, vertical gardens, vats, yeast colonies. Caged critters, maybe.

TL11: 125 dtons/person: vertical gardens, vats, yeast.

TL12: 64 dtons/person: a garden, vats, yeast.

TL13: 32 dtons/person: vats and yeasts.

TL14: 16 dtons/person: yeasts.

TL15: 8 dtons/person: yeasts -- or worse.

TL16: 4 dtons/person: whatever it is, it's horrible.

TL17: 2 dtons/person: don't ask, don't tell.

TL18: 1 dton/person: cram.

TL19: 0.5 dtons/person: supercram.

TL20: 0.25 dtons/person: food is teleported directly from a nice Ag world into your stomach.

 

[Scott Martin]

Hey Robject

The real issue isn't volume, it's usable surface area. the proposed *minimum* diameter for a spun habitat is a mile in diameter (which means that most people won't get disoriented by the turning of the stars / sun / whatever)

that means a *lot* of cubage.

That's why I asked what you were trying to do. There is a big difference between building a place where people *want* to live and where people *can* live. I *can* live in a university residence room, sharing a 150 square foot room with a roommate, and a 400 square foot lounge with 80 or so fellows, but I would *prefer* to live in 1500-2000 square feet of house with my wife and daughter and have a convenient couple of acres to roam around in.
(edit I meant 1500-2,000 square feet, not 1,500-200 square feet)

The solutions that you are proposing are "habitable" (as in possible) just like the dorm room is "habitable" but if the cost of "upgrading" living space is incrementally small, expect more people to opt for the nice habitat.

What is the average income for a tech/11 society? I'll build an archology assuming that the cost per person must be less than 2 years of gross income. that will give you a reasonable feel for the "median" size habitat, which is inline with what our current world is (a "typical" house sells for about 5x what the principal wage earners gross income is, divided among ~2.5 people per household)

I do plan to reduce the "cost" of the extended life support by an order of magnitude though, just a heads-up in advance. Water treatment facilities on cruise ships and naval vessels (volume constrained) are at least that much more expensive than "fixed" treatment facilities.

Scott Martin

 

[parmasson]

TL16: 4 dtons/person: whatever it is, it's horrible.
TL17: 2 dtons/person: don't ask, don't tell.
TL18: 1 dton/person: cram.
TL19: 0.5 dtons/person: supercram.
TL20: 0.25 dtons/person: food is teleported directly from a nice Ag world into your stomach.

The movie is called "The Matrix" I think

 

[Scott Martin]

The bottom end of the life support spectrum looks to be 6L of algae per person, which will keep you alive (assuming enough power for photosynthesis) "forever"

http://www.projectrho.com/rocket/rocket3g.html

Too much green slime makes Jack a dull boy...

But still the discussion of "possible" vs "desireable". If it's not "desireable" then people will just move...

Scott Martin

 

[Fritz_Brown]

Well, Scott, your treatment facilities are fixed. This isn't some wet navy destroyer here - even an aircraft carrier only carts about 5k people around. My space arcology is based on 100,000 - yours is even bigger.

Based on what a couple of folks mentioned, is anyone seeing folks living on the outside of this thing (a space arcology)? I am envisioning everyone living inside - basically "under" the park.

I'm also not seeing most of the rabbits/guinea pigs running free - but living in little meat farms until their appointed time. If everyone gets the equivalent of a bunny every two days, I think they will be quite happy. No hunting will be allowed - except for the rats. Kill and eat as many of those as you like.........

 

[robject]

Scott, I think you're right. Those numbers I'm churning out are for minimal life support. And I'd rather live in a nice place than a nasty one, any day.

And I'll say you're also "right" about the larger number for an "optimal" environment. Would it be considered luxurious, or simply okay?

Minimal: 2^(18-TL) dtons per person
Nice: 2^(24-TL) dtons per person?

 

[Fritz_Brown]

Oh, and I don't think there will be that steep of a drop-off with TL. There is only so compact you can make your nutrition - even with nothing but algae vats. (Well, OK, you can make it smaller by just using your dead.

) You will get some efficiencies with air and water recycling, and some marginal improvements with hydroponics, but not much.

BTW, here's an idea: TNE adventure on a failed arcology. They couldn't sustain themselves as TL fell off (only slightly), and population dropped significantly. So there is a large, mostly empty arcology with rabbits and guinea pigs (and maybe some zoo critters) running loose, the park gone feral, and some crazy folks living "underground". (Doesn't have to be TNE - it just fits with the themes.)

 

[Scott Martin]

Hey Fritz, a rodent is a rodent, eat whichever you like. I suspect that the pointy-nosed ones have more recipies in China than the snub-nosed ones...

The cylinder archology has everyone living on the inside of the curved hull, with the hull spinning at ~1 rpm to generate artificial gravity.

The "concept" drawings have "habitable" area 3 of 6 "panes" with the other 3 being transparent (well OK, seriously UV blocking) to allow light into the structure. three "vanes" spread out from the "glass" areas to reflect light from the local star, which is aligned along the axis of the cylinder. for "Night" close the "petals".

The point that I am trying to make is that living under a 3m ceiling for long periods would *suck*. I speak as someone from the North, where "cabin fever" and "Seasonally Affected Disorder" (SAD) can be real medical issues. some of this is light related, and that would need to be dealt with regardless, but can you imagine living your life in Manhattan and never having the option to leave? no vacation, no time in the woods, not even the chance of a cruise ship. Now take Manhatatn and cover it over so that you can never see the sky, and tell me that chunks of the population wouldn't start to go seriously snaky (more so than they started)

Robject's 2000 dT per person with "forests" and "wilderness" doesn't have any wilderness, or trees: it's a 150m x 200m x 6m box, and to me trees are more than 6 M tall.

The "volume" enclosed by more massive structures is effectively "free" since you are really paying for the hull. For large structures the total area of the hull approaches the area you can stand on, so the cost for 1 km of "ceiling" is the same as for 3m of "ceiling"

larger volumes also give you much better survivability in case of hull breach, since you can afford to lose more atmosphere while looking for the breach.

Scott Martin

 

[Fritz_Brown]

Oh, and robject, you need to get your head out of Texas. (Same thing for you Scott! ) Lots of folks live in places with a lot less elbow room and love it (not me, but I'm just saying...). The Japanese and Singaporeans live pretty tight and don't mind too much. (I'm being generous in living space, BTW, compared to a couple of hotel rooms I've had in Japan. ) And, you're not going to get any Montana ranchers moving up there - Big Sky to No Sky isn't going to draw that kind of person.

Having said all that, I was looking at a middle class society for my numbers, but you could definitely plus it up for more pleasantness (a few open fields for sports, larger pads, etc.)

Also, I am assuming grav technology - not spin. And, I was running my numbers based on a sphere - not a cylinder. A cylinder will have more floor space for the same volume, though you couldn't have a point "sun" if you have a cylinder - don't know if that would be extra freaky or not.

 

[Scott Martin]

I think that trying to run a power series on volume is just asking for trouble. The real value is likely to be a log / limit function with the minimum size based on some psychological minimum volume limit. I'm sure that you could experiment on people to eliminate the "big spaces" people, but I'd probably be one of the first to go. Here's hooping that I'm never part of that type of experiment.

I think that arcology volume will probably be based more on economics than "survival" An appartment dewller now has a lot more "personal" space than most nobles at TL 2, despite the fact that we have less "surface area" per person on the globe. I think that when we run out of ways to "stretch" the area on the globe we'll need to head out and make some.

If the median income increases with tech level, and real costs drop with tech level (this is what Traveller models) then a higher tech level person can afford more personal space than a lower tech level person. It is insane to assume that they won't *want* it.

Scott Martin

 

[Fritz_Brown]

Look at my calculations, Scott - they assume (with a sphere) a "ceiling" in the park of 90m or so. I will have plenty of trees and bushes - just no mountains. The 3m ceilings are only in the living and working areas - you know, where you currently have a 2.5-2.75m ceiling.

The light issue is one of the reasons I might prefer a sphere - you get a point source of light. Of course, with TLsomething, you might be able to make it appear as if the light were a point source that moved from "east to west" down the length of the cylinder.

 

[Fritz_Brown]

Well, remember, Scott - these are (maybe) folks who don't have a better option. They would live on the mainworld in the habitable zone - if this star had one. Or, if the world weren't crawling with 600,000,000 sophonts. Or, if they weren't manufacturing things that kill everyone on the planet. Or.....

(But, you're right - my assumptions are slightly different from yours and the middle somewhere is good.

)

 

[Scott Martin]

Fritz

You can get a "point sun" using mirrors and a cylindrical design, but IMO you're more likely to use non-imaging optics to allow an increase of the ratio of "land" to "sky" in the cylinder.

I think that the rest of your points are adressed in my last cross-post

I'll note that one of the reasons that real estate prices in Vancouver are so "high" is because they are incredibly cheap to visitors from Japan, Singapore, Hong Kong... so yes, people are willing to live in cramped areas, but if they can, they will find other options.

Scott Martin

 

[Scott Martin]

If you are using gravitics, why not use a cube? curved surfaces really crap out when you start getting towards the middle of them, and curvature starts getting noticable. I think that I'd find anything with less than a 20m diameter "Uncomfortable" based on the perspective issues.

If you're using grav, why have the floors curve? My floors *have* to curve, because that's my only possible configuration. It also means I'm not screwed if a breaker gets tripped: I can just imagine needing to get Johnny down from 60m in the air because he was in the park when someone turned on one too many mix-masters

Scott Martin