Haven't had time to read the paper yet, but the blogger seems to miss the obvious. We could probably assume civilizations capable of interstellar trade would have advanced enough genetic engineering and biological 3D printing such that trading lifeforms and their by-products between planets wouldn't be required. Different planets, with different atmospheres, geologies and ecosystems, would lead to comparative advantages in production though, which is the primary incentive behind trade relations. However the net benefit of trading would be at least partially offset by the cost of transporting goods over such long distances. With low thrust, high efficiency engines attached to the cargo the cost could be low enough to make trading an economic benefit, but that would require even longer time periods between the production of a good and its being put to good use. Civilizations would have to plan ahead and estimate the supply and demand many years, centuries or millenia into the future. You could really have a lot of fun with this kind of analysis. Looking forward to reading the full paper later.
>Civilizations would have to plan ahead and estimate the supply and demand many years, centuries or millenia into the future.
With even informational signals taking years to decades to centuries each to reach their destinations, our current knowledge of physics implies that a civilization basically needs to achieve indefinite cultural lifespan before they can do anything interstellar whatsoever.
So once you've got people who can maintain records and culture over centuries on detailed matters (or who just plain live that long), it's really not that much of an obstacle. But it's a nastily high mountain to climb in terms of bootstrapping your interstellar empire.
> Different planets, with different atmospheres, geologies and ecosystems, would lead to comparative advantages in production though, which is the primary incentive behind trade relations.
Not just advantages - some organisms rely on extremely complex symbiotic relationships and environmental stimuli (e.g. fungi in the genus Morchella). Reproducing these conditions, even with advanced technology, could be extremely challenging or impossible, which could create enough demand to justify physical transportation of goods. (This is essentially the plot to the science fiction novel I'm writing.)
"Reproducing these conditions, even with advanced technology, could be extremely challenging or impossible, which could create enough demand to justify physical transportation of goods. (This is essentially the plot to the science fiction novel I'm writing.)"
That was the main idea in Frank Herbert's Dune - "the spice". It's a good strategy to follow a tested winning idea, good luck with your writing!
Tell me, have you read the original Dune and the accompanying Dune Encyclopedia? They're basically the foundations of the fictional science of terraforming ecology.