PDA

View Full Version : "The Theory of Interstellar Trade"



fmitchell
03-17-2008, 04:48 PM
Many of you might have seen "The Theory of Interstellar Trade" (PDF) (http://www.princeton.edu/~pkrugman/interstellar.pdf), a semi-humorous paper that popped up on Slashdot and elsewhere.

However, I've been pondering the problem slightly more seriously with reference to a possible SF game I might run. So I put the following question before the group:

Assuming that the speed of light in a vacuum is the maximum speed goods and information can attain, and assuming human lifespans top out at 125 to 150 Earth years, what economic and political structures, if any, could humans maintain across interstellar distances?

Inquisitor Tremayne
03-18-2008, 11:39 AM
Assuming that "we" would be attempting to set up some sort of galaxy spanning democracy, I think the first "problem" that needs to be overcome is being able to think globally. Using our current situation on earth present day, we are still too scattered and divided to be able to work together as a whole planet.

There would need to be some sort of globalized central government that had a representative that could speak for the entire planet.

There would also be the need for interstellar communication. IF it is possible to speak to galaxies far away in real-time then establishing economic and political structures become more feasible.

This is just off the top of my head and I don't know much about governmental practices etc...

Farcaster
03-18-2008, 01:00 PM
Assuming that the speed of light in a vacuum is the maximum speed goods and information can attain, and assuming human lifespans top out at 125 to 150 Earth years, what economic and political structures, if any, could humans maintain across interstellar distances?

I'm thinking: none or practically none.

The distance between interstellar planetary bodies of interest would be too great to have any kind of meaningful trade or economic relationship if travel was limited to light speed only. I suspect that you'd have economic bubbles that spanned over single solar systems. There might be limited trade with nearby solar systems at best. The nearest planet to Earth, for example, would take ten years to reach by light speed travel. We could feasibly trade with planets at that range, but not much further. And I certainly doubt that any kind of feasible political structure could be maintained from even that distance.

Now, there might be some kind of loose coalition between these interstellar entities. That might be doable, but the individual solar systems would still pretty much have to operate on their own.

boulet
03-18-2008, 01:19 PM
I agree with Farcaster and it explains why so many scifi authors have used the idea of hyper drive : if limited by speed of light, it's impossible to have a typical story that involves different systems unless it spans on several generations...

kipling
03-18-2008, 01:21 PM
I suspect that you might get some of the looser forms of empire, because unless enough stuff were sent all at once. the colonies would be dependent on shipments from home for certain things.

Greg Costikyan had a thought or two on trade in http://www.costik.com/inttrade.html. You might look at that as well.

fmitchell
03-18-2008, 07:15 PM
For the record, I tend to think, in a world without any sort of FTL, each planetary system would have to stand on its own. Colonists of a new system would have to arrive with at least enough to establish a self-sustaining ecosystem, and ideally terraforming tools/equipment so they don't have to live in one little bubble for decades or centuries until the next ship comes.

The only economic and political links between these islands would be STL ships (generation, sleeper, or hybrid), and if feasible some light-speed communications between planets. The ships would bring additional supplies, new technologies, news from previous stops, and military reinforcements for conflicts known at its time of departure (years or decades ago, perhaps centuries). It might be a good idea for each ship to have its own standing marines, in case unscrupulous "world-huggers" try to plunder the starship.

Communication between the stars would be faster, even at light speed, but there's only so much a theoretical central authority could do by talking. Perhaps they could keep an empire together through a shared ideology (or a shared threat), or provide a reliable source of knowledge and planning to keep new and old worlds going. Unless they're superhuman, though, can they really stay relevant for decades, centuries, millenia?

Also, as Greg Costikyan says, imports from across the stars will be prohibitively expensive. That's hardly a liquid market, so the paper I referenced earlier probably doesn't apply. The only goods that can cross the stars are bound to be priceless, or beyond monetary value. The ones I can think of are:


Survival: A group of people, or indeed humanity as a whole, would face extinction unless they leave their system for another.

Non-monetary values: A species with nigh-unlimited resources and sufficiently advanced technology decides to venture out to the stars for their own reasons.

Unique Items: The residents of a planet, or a planetary system, would pay for artifacts or knowledge that they could not reproduce themselves, such as highly advanced technologies, scientific principles beyond their current ability, or (especially in a starting colony) goods and services beyond their current industrial capacity.

A New Life: Assuming a pre-existing system of interstellar travel, some humans (and other species) might forsake their current lives for a fresh start elsewhere, in a brand new world. (In some ways, this is an individual version of the previous reasons.)

And, yes, that's why FTL makes most science fiction stories easier. Even something like Ursula K. LeGuin's ansible, which allows near-instantaneous communication between the stars, would be a huge advance in empire-building. But, to paraphrase Gregory Benford, FTL is "playing with the net down" ... so I'm taking this tack to find interesting stories if we take the "science" in science fiction seriously.

P.S. The world I was thinking of, which I've probably mentioned before, goes a bit like this:

The only three interstellar powers are humans, the aliens known as the "Elders", and the Machines. Humans have ventured out to the stars in waves, as a result of planetary disasters, wars, and ideological conflicts; human attempts at a unified Empire of Man have fallen apart, and at the present time they're allied with the Elders. The Elders, who travelled the stars when dinosaurs still roamed the Earth, have their own enigmatic reasons for crossing interstellar distances; as far as anyone can tell, their homes *are* their gigantic starships, ferrying humans and their gear across the stars. The Machines, some also older than Man, are self-aware AIs that, almost inevitably, rebel against their organic creators; because they have far fewer needs than organics, they have colonized various airless worlds and spaces between worlds, from which they occasionally make war against organic life.

tesral
03-19-2008, 04:05 PM
I suspect that you might get some of the looser forms of empire, because unless enough stuff were sent all at once. the colonies would be dependent on shipments from home for certain things.

Greg Costikyan had a thought or two on trade in http://www.costik.com/inttrade.html. You might look at that as well.

How could you get any form of Empire? By the time you enforcement forces arrived the government that sent them would likely be out of power. Empires are formed by force.

Without FTL trade and government across the interstellar void are not possible on the Human scale. You either find what you need in the system you are are in or you do without.

Say it takes ten years to make the trip to the nearest planet. We will assume for the sake of argument that the ship can travel perfectly at the speed of light. Colony X needs McGuffins. They send word to Earth they need McGuffins, in ten years Earth gets that message. They pack them up and ship they out. In ten more years Colony X has McGuffins. Twenty years to get McGuffins. Hardly an efficient ordering system.

It wouldn't likely be even that fast. You could easily be looking at a round trip duration greater than a Human lifespan. Getting crews would be your hardest part.

No trade, all trips are one way. You would have bare contact, little more. Government isn't possible regardless of form. The only real item of value would be information. Books, music, knowledge, they would be the only thing that would be worth exchanging. That slow, slow flow of knowledge would be the sole contact between far flung islands of the Human race.

fmitchell
03-19-2008, 04:38 PM
No trade, all trips are one way. You would have bare contact, little more. Government isn't possible regardless of form.

You're forgetting the ships themselves. Unless ships themselves are also one-way, a starship crew/clan/guild can take aboard interesting information and artifacts speculatively, and sell them at future ports-of-call. It's a risky and perhaps not very lucrative existence, but there's still a trade of sorts.

Ideally starships, like colonies, would be self-sufficient; they could gather raw materials from space or uninhabited planets, and recycle food, water, and air for the whole (living) crew. If a merchant starship has to rely on trade for its very survival, one mistake could end the business and perhaps the crew as well.

If the starshipmen aren't merchants but representatives of the government, then they have some influence by withholding information, services, or goods that a planet wants unless it conforms to the government's wishes. It's a tenuous sort of control, but if you tied together government and religion -- say, a religion that venerated the starshipmen as agents of their god -- then you could get planetsiders to behave the way the starshipmen want them to.

But you are correct: no government has persisted more than a few hundred years, and many have lasted mere decades, which is a small span compared to travel between the stars. (Religions have lasted longer, thousands of years, but they have changed dramatically over those millenia.) You'd have to assume either complete stagnation or superhuman planning abilities.

The moment that individual planets decided they didn't need the starshipmen -- and truly, they likely don't after they've become truly self-sufficient -- then the starshipmen cannot demand, only advise and persuade.

GBVenkman
03-20-2008, 01:37 AM
A lot of the distance would be bypassed if you could bend space-time.

stephen hawkings is a good read about it all. Physics teachers like to talk about it too.

The whole "what's the shortest distance between the top end of the paper and the bottom mark?"

*takes paper, folds in half and punches a pen through the two marks*

kipling
03-20-2008, 09:48 AM
How could you get any form of Empire? By the time you enforcement forces arrived the government that sent them would likely be out of power. Empires are formed by force.

Without FTL trade and government across the interstellar void are not possible on the Human scale. You either find what you need in the system you are are in or you do without.

Say it takes ten years to make the trip to the nearest planet. We will assume for the sake of argument that the ship can travel perfectly at the speed of light. Colony X needs McGuffins. They send word to Earth they need McGuffins, in ten years Earth gets that message. They pack them up and ship they out. In ten more years Colony X has McGuffins. Twenty years to get McGuffins. Hardly an efficient ordering system.

It wouldn't likely be even that fast. You could easily be looking at a round trip duration greater than a Human lifespan. Getting crews would be your hardest part.

No trade, all trips are one way. You would have bare contact, little more. Government isn't possible regardless of form. The only real item of value would be information. Books, music, knowledge, they would be the only thing that would be worth exchanging. That slow, slow flow of knowledge would be the sole contact between far flung islands of the Human race.

You are right on most of it; I do not (sorry for the stilted speech, my browser pops me out whenever I type an apostrophe, which has never happened before, so I am somewhat at a loss) think that there will be much besides communication between planets. You can probably "sell" how-to-build-cool-thing-X but I am not sure what the currency would be. Credit on the colony planet, maybe, but how do you enforce it?

When I spoke of empires, the colonies probably proclaim fealty of some sort to the mother planet, but there has to be redundancy in the system: multiple ships sent to each target, each ship with all of what is needed for survival, and so forth. The fealty might be in name only: a decade is a long time to sent an army.

Colonization ships are also a big investment. Is the mother planet in trouble, that it is willing to send this much out?

And do the ships travel at a high fraction of C, so that a light year voyage takes a year and a bit, or a low fraction of C, which means that communication becomes more important?

tesral
03-20-2008, 01:22 PM
Colonization ships are also a big investment. Is the mother planet in trouble, that it is willing to send this much out?

And do the ships travel at a high fraction of C, so that a light year voyage takes a year and a bit, or a low fraction of C, which means that communication becomes more important?

Colonization is enlightened self interest. Sending out colonies assured that should something happen to the home planet the species will continue.

The problem with religion is it has a "what have you don't for me lately" factor. The planets don't need starships. We have never had them and survival is more than possible, we thrive. A colony sent out is a colony gone. Another stab at planting the human race on another planet. Without FTL trade, government even religion is a laugh. Human memory isn't long enough to keep it going. You could have mobile colonies that traded things form world to world, but they would, again, do it for themselves. Depending on the speed of the ships a planet fall could be a once in a lifetime experience. If they get close enough to c don't forget time dilation. On the starship time is slow, they hit planet after planet and never meet the same people twice.

fmitchell
03-20-2008, 02:17 PM
Colonization is enlightened self interest. Sending out colonies assured that should something happen to the home planet the species will continue.

This assumes a) that future societies might know potentially habitable extrasolar planets to settle on, b) that closer candidates like the Moon or Mars are somehow unacceptable, and c) that the threat of planetary catastrophe is real enough. While not out of the bounds of possibility, it shows more enlightenment than humans have demonstrated so far.


The problem with religion is it has a "what have you don't for me lately" factor. (...) Without FTL trade, government even religion is a laugh. Human memory isn't long enough to keep it going.

Certain real-world religions have been going for more than a millenium, predicated on an unreliable and unseen deity who nevertheless promises eternal torture for the disobedient, and eternal delight for the obedient. Reports of their death have been greatly exaggerated. Using the same principles as today, starship-friendly cults, seeded by starships themselves, could sustain themselves ... maybe even become major religions of their planets. Remember the Cargo Cults? Imagine someone creating them on purpose.

In fact, it doesn't necessarily require religion, per se, just history. If the starships that came to New Trantor before bore wonderful gifts, then the residents of New Trantor will eagerly welcome the next starship ... even if wiser heads advise caution.

P.S. Actually, what interests me in an STL-only universe is the notion of "never going home again" ... once you commit to starship life, or even emigration across the stars, you're effectively severing all ties to the people you knew planetside. And let's face it, in a lot of RPGs you meet most NPCs once.

tesral
03-21-2008, 10:34 AM
Certain real-world religions have been going for more than a millenium, predicated on an unreliable and unseen deity who nevertheless promises eternal torture for the disobedient, and eternal delight for the obedient.

However they have pushers located around every city called "churches". The religion is there, constantly, it has rituals to keep it going. "The starship is coming" religion had better produce a starship on a regular basis or it isn't going to last.

fmitchell
03-21-2008, 12:20 PM
However they have pushers located around every city called "churches". The religion is there, constantly, it has rituals to keep it going. "The starship is coming" religion had better produce a starship on a regular basis or it isn't going to last.

Well, the Church of the Celestial Messengers (or whatever) can have rituals, temples, etc. which do the usual religious stuff ... but have, as part of their dogma, that any Celestial Messengers that do show up are emissaries from the Divine.

Or, one could go the route of the Bene Gesserit (sp?) in Dune: take existing religions, and seed beliefs that a member can use while in trouble. The Bene Gesserit instilled a respect for spice-addicted women with spooky abilities; the starship folks could instill prophecies that travellers from the heavens bring great wisdom, and harming such travellers brings karmic retribution ... particularly if they have their own spooky training.

Never underestimate the gullibility of the human race.

tesral
03-22-2008, 02:05 AM
Or, one could go the route of the Bene Gesserit (sp?) in Dune: take existing religions, and seed beliefs that a member can use while in trouble. The Bene Gesserit instilled a respect for spice-addicted women with spooky abilities; the starship folks could instill prophecies that travellers from the heavens bring great wisdom, and harming such travellers brings karmic retribution ... particularly if they have their own spooky training.

Never underestimate the gullibility of the human race.

They had the advantage of FTL. The Starship people have nothing to keep the religion from drifting or the planet-bound "protectors" from using it for their own glorification. Never underestimate the lure of power to corrupt.

It just is not controllable. There is not way to communicate to everyone no way to exercise any degree of central authority that you need to run a large and wide spread religion.

Communication is the key to any such system and without effective communication, it can't work. STF spaceflight does not give you a quick means of communication. If the planets are ten light years apart at best you get light speed messages. 20 years round trip for a message. The point of the question will long be moot before it is ever answered. So people are not going to look to an outside agency for answers.

Look into the role of communication in history. It wasn't lead that destroyed Rome, it was communication. The Empire got too large to effectively communicate with its own frontiers. Many many times they tried to alleviate that problem. Splitting the Empire into four sub Empires, didn't work, again splitting into East and West, didn't work. It could take as long as a year for Rome to respond to a crisis. Well by the time the Legions got there, problem was ever solved by everyone being dead, or it was solved locally. That was only a year's delay. 20 years? Not happening. It's outside realistic Human scale.

boulet
03-22-2008, 08:42 AM
The Empire got too large to effectively communicate with its own frontiers. Many many times they tried to alleviate that problem. Splitting the Empire into four sub Empires, didn't work, again splitting into East and West, didn't work.
It actually did work : the Roman Empire in the East survived the original Rome centered Empire by thousand years. Under Justinian the Great it even got back to the western shores of the Mediterranean sea.

But the point you make is still valid. For instance Genghis Khan extensive territory conquest had a lot to do with his talent at organizing communications and logistics of his nomadic people thus being able to react to unrest all around the empire.

I'm not convinced great religions are always related to centralized models. Islam isn't centralized, Judaism, Orthodox church, Buddhism aren't either. Still they're widespread. I don't really understand why it would matter much concerning our discussion about interstellar trade anyway.

fmitchell
03-22-2008, 05:29 PM
I'm not convinced great religions are always related to centralized models. Islam isn't centralized, Judaism, Orthodox church, Buddhism aren't either. Still they're widespread. I don't really understand why it would matter much concerning our discussion about interstellar trade anyway.

I guess we got off on using religion to ensure interstellar traders would get a friendly, and possibly even obsequious, reception. (And possibly a tangent about interstellar organizations imposing their will on individual planets.)

The idea of starships being mobile self-sufficient colonies trading with planets for information, goods, and services, though, is certainly workable. Ships could not only provide advanced technology, but extra industrial capability, mercenaries (particularly for unpopular or unstable planetary governments), and . Counting on a ship to arrive would be inadvisable, unless they have regular routes, but the arrival of a ship could quite literally make history.

What would the ships get out of it? Something besides endlessly recycled air, water, and food. Also, if sustaining a religion among planets is hard, sustaining a religious or quasi-religious belief in endless travel and a duty to preserve humanity among a small group in a confined and dangerous environment isn't.

While I never finished Cities in Flight, I like the idea of starships as itinerant workers. Colonies can talk to each other (over decades or millenia), and can pass along information about which ships aren't to be trusted. Like hobos, ships could leave "signs" at each system, perhaps as a beacon on the edge of the system, that advises subsequent ships about the sort of reception they're likely to get. Over time, reputations can build up, and systems visited "often" by ships could build up an infrastructure to make trade easier: ship reception stations, interstellar communication arrays, etc.

gdmcbride
03-23-2008, 06:00 AM
Twenty years is a drop in the bucket. We have discovered an 'Earth-like' planet in what astronomers consider our back yard at mu Arae. It is a close 50 light years away.

That would make near-FTL round trips a hundred years from earth, even assuming that the planet is habital (and it probably isn't).

Our galaxy is 100,000 light years across and an estimated 1000 light years thick.

The sort of social dynamics that would make 100 years round trips (or a 1000 or a 100,000) economical and viable seem completely outside the realms of humanity as we now know it. 'Cities in Flight' is interesting as speculative fiction -- but would you really trust thousand year old information that told a planetary culture is unreliable?

Granted, thanks to transhumanist technology, humanity might very radically change in the not too distant future. Perhaps if someone were to perfect technology that made humanity effectively immortal a hundred years or even a thousand might not seem so long.

Gary

nijineko
03-27-2008, 05:47 AM
teleportation is already a reality. here's a bit about it. (http://www.research.ibm.com/quantuminfo/teleportation/)

basically, it turns out that the sci-fi people are right. "quantum entanglement" does work. the only catch is that the process destroys the original to create the exact duplicate elsewhere. now, this would work perfectly for information and communication. while it does not violate any law that the scientists can find, don't expect living things to be teleported anytime soon. so far it's been just single atoms.

here (http://en.wikipedia.org/wiki/Quantum_teleportation) are some more (http://en.wikipedia.org/wiki/Teleportation) bits (http://www.cnn.com/2007/TECH/science/10/10/human.teleportation/) about it.

Frobozz
03-27-2008, 07:54 AM
Entanglement is wild stuff. Quantum computing is getter farther and farther along. I think the largest quantum processor right now is 28-qubits; though it doesn't allow entanglement. The largest processor that can fully entangle it's information is 4-qubits.

A fully entangled Quantum Computer means that, if it was running let's say 200-qubits, vs a normal computer, could, every clock cycle, do an operation on 2^200 or 1.6x10^60 machine states(!!!!), while a normal computer can only do 1.