I'll be at... Chicon 7...

Hello! May we Metafilterans buy you some really great pizza? Mr. Scalzi says he will also try to be there.

Is there still room for moral structure in SF societies and worldbuilding? How does moral ambiguity represent or fail to capture the real world? What are its pitfalls YES

Try reading Le Guin or Linebarger for the answers to that .... Or Stapledon, for that matter!

See comment on MeFi thread. OK?

I'm pretty sure you have, but just in case you haven't (and for generical all-purpose edification)... have people seen this seminal paper? 'On the theory of interstellar trade', Krugman, 1978. It discusses the economic effects of time dilation. (As the cargo ages less rapidly than the endpoints.) Contains maths!

http://www.princeton.edu/~pkrugman/interstellar.pdf

Yes, I saw it. (I read it and concluded it had nothing useful to say for the universe of "Neptune's Brood", where interstellar travel speed maxes out at 1% of c ...)

Is trade limited to the exchange of physical goods, or could information goods be sent by radio using encryption?

Xor shares / encryption keys - this can be useful for establishing identity, whereas someone radioing you from another star system could be anyone.

exchange of scientific papers (but that may occur for free and not be trade)

news / cultural products might all qualify as trade - I think that a specific company type would come into existence to promote interstellar sales of cultural goods in the receiving solar system.

physical goods: Better object printers cpu cores, better-than-silicon chips, possibly quantum / optical chips, memory / flash cores. seeds, which is not quite the same as information

information by starwisp.

scientific samples in general, which could be taken back to a more suitable lab (especially from a poorly developed world or world in the early phases of settlement)

replacement parts for machines not fabricateable there.

really, this trade seems to split into "early colony world to mother world" and "advanced world to advanced world", with some trades only suitable to one of those.

I've always found this subject fun.

I presume the issue isn't "are there goods produced in society A that would be useful/could be sold at a profit to society B?" It's "Given that societies A and B are many light-years apart, can there be meaningful trade if B won't see a return on investment until at least 2d years later (where d is the distance between A and B in light-years)?" Even if the typical distance is only 10 light-years, which seems above a bit optimistic, that's a 20 year wait for the payoff.

I think the answer may well be "yes, but only via middlemen". Instead of direct trade between A and B, you have independent merchants/ship-owners who buy goods off A on the assumption that they will be able to sell them at a profit to B (or, if not B, then C, D, etc.). I don't pretend to be an economist, but I suspect this model works best of the ships are large enough that the merchant societies actually live on ship rather than having a planetary base - like Cherryh's Merchanters (who do have FTL travel, but the model would work without it).

In order to make a profit (which you need to replace non-recyclable items of your ship ecology, expand your fleet, etc.), you need to be able to anticipate, not what society B needs now, but what it's going to need in N rest-frame years later when you get back. (Note that if the technology involves ships that travel close to c, the time lapse is much less than N years for you.) This will be easier if trading with early-stage colonies, whose development is probably easier to predict than advanced societies (where fashion trends will be a key issue: you might invest in a cargo of, say, exotic intoxicants, only to find when you get back that some charismatic religious leader has convinced the population to eschew all such substances). To spread the risk, you probably have a route involving more than two trading societies - if your vintage wine is no longer saleable to the Holy Theocracy of B, you can probably still make money on it in the People's Democracy of C.

There may be a model for this in ancient Polynesia - I seem to remember reading once about a system whereby material traded on from island to island, way out of the range of any individual peer-to-peer direct contact. Similarly, items are found in archaeological sites in the UK that have come from sufficiently great distances that direct one-to-one trade seems unlikely.

Hey! What happened to the makerbots visit in Brooklyn?

(I'm afraid I ruined things by pointing out that there was little likelihood of beer :() Any other possibilities in the NYC area?

I'm checking ...

No Seattle this time? That's too bad.

The most economically useful trade is in information, but the optimal way to organize that is communism - point gigantic com lasers at each other, beam a copy of everything of value/potential interest. This is likely to be a very loopsided trade, but as long as all parties derive more economic benefit than the cost of keeping the laser array running, it is stable, and delivers maximum value to everyone concerned. - This does mean you will be getting a copy of what everyone is producing for local consumption, rather than anything tailored to your preferences, but the time delays make this the only practical solution.

Other things worth sending between the stars...

The initial seedship?.. and thats it, I think. Everything else is better sent as information. This does assume the capability to do nano assembly, but this seems fairly reasonable for any civilization capable of reaching the stars without "cheating" Einstein.

Please check my Native Guide – Chicon Edition. I think I've succinctly covered what people might want/need to know/find while at Worldcon.

Charlie has been thinking about these problems, and they're part of the plot and background of Neptune's Brood.

Which he has finished writing.

So there are interesting questions, but he's going to the Worldcon, and you might not get much of a response. But I reckon he's way ahead of you.

Bobh: see Makerbot fixture (I was looking at an early draft of the schedule that didn't have this).