The Resources of Interstellar Civilizations [Space]

[AlexanderHowl]

When we examine logical extrapolations of the size of interstellar economies, we start to run into very large amounts of money. For example, a TL10 civilization with 1400 star systems and an average of 1 billion people per star system will average a GDP of $93.8 quadrillion per year. If we assume that the cost of the largest spacecraft will be 0.05% of GDP (similar to the ratio of the US economy to the cost of supercarriers), such a society could easily afford capital ships with a cost up to $43 trillion, meaning that they will likely have some very large spacecraft.

How do you show the scale of such a civilization in your settings? Even if your games are just on backwater worlds, there should be some evidence of the scale of interstellar societies. Of course, the worlds themselves could be the evidence, as terraforming worlds would be quite expensive, but I doubt that an interstellar society would terraform a world for colonization and then just leave it alone after they colonize it.

[jason taylor]

Originally Posted by AlexanderHowl

When we examine logical extrapolations of the size of interstellar economies, we start to run into very large amounts of money. For example, a TL10 civilization with 1400 star systems and an average of 1 billion people per star system will average a GDP of $93.8 quadrillion per year. If we assume that the cost of the largest spacecraft will be 0.05% of GDP (similar to the ratio of the US economy to the cost of supercarriers), such a society could easily afford capital ships with a cost up to $43 trillion, meaning that they will likely have some very large spacecraft.

How do you show the scale of such a civilization in your settings? Even if your games are just on backwater worlds, there should be some evidence of the scale of interstellar societies. Of course, the worlds themselves could be the evidence, as terraforming worlds would be quite expensive, but I doubt that an interstellar society would terraform a world for colonization and then just leave it alone after they colonize it.

Doesn't that depend on the goal? If it was terraformed so someone (s) of high status could have a manor it might have a fairly small status.

What if it is training grounds for the military? That would require more people but not colonists per se.

What if it is being kept in reserve in the event of a population spurt, need to move potentially disruptive subjects, etc?

Or what if it is designated wilderness? An interstellar civilization could have whole planets as nature reserves.

[ericthered]

For warships especially, it depends on how hard it is to travel between star systems. If travel is difficult, smaller vessels may be more needed than large ones.

In my current space game, I try to emphasize the size of the setting by portraying a proxy war in which dozens of capital ships are in play, all fielded by the lesser polities.

I don't know that I ever try to emphasize the size and graunduer of an interstellar empire. It tends to depower the player characters. In fact, I look for ways to reduce the scope.

If I want enormous industry, I'm more likely to portray a solar system edging on K2 status, mostly via cities in cans.

[Anthony]

There's no strong reason to assume any particular ratio of GDP to amount spent on one asset, it depends on what the strategic and tactical needs are.

[Crystalline_Entity]

Originally Posted by AlexanderHowl

When we examine logical extrapolations of the size of interstellar economies, we start to run into very large amounts of money. For example, a TL10 civilization with 1400 star systems and an average of 1 billion people per star system will average a GDP of $93.8 quadrillion per year. If we assume that the cost of the largest spacecraft will be 0.05% of GDP (similar to the ratio of the US economy to the cost of supercarriers), such a society could easily afford capital ships with a cost up to $43 trillion, meaning that they will likely have some very large spacecraft.

Don't forget that as the wealth of a nation changes, people's expectations of what their taxes provide will change too. In the 19th century, people started to expect governments to provide free education; in the 20th century, people expected their governments to provide free healthcare; who knows what governments will be providing by 2100! For example, there might be an expectation of free genetic upgrades to your children (something like Resistant to Disease would save millions in potential future healthcare costs). People may live longer, requiring expensive cybernetic upgrades, bioengineered transplants etc, to give them a good quality of life.

In an ultra-tech setting citizens and governments of rich worlds have vastly more things to spend their money on. They might also want more leisure time, and part-time working will reduce an ultra-tech government's tax revenue.

There might also be vastly more people to provide these things to; "death" might be a rare occurence, especially if non-destructive uploading and downloading the brain is possible; then you'll have an ever-increasing population expecting all of the above. That $93.8 quadrillion might not go as far as you think!

[Pomphis]

OTOH 1 billion per planet is a lot. It might equally well be 10 millions. And not all planets must be fully contributing members. There may be many worlds that are more like protectorates.

[AlexanderHowl]

If a system has less than 500 million people, it will likely have difficulty maintaining a TL10 society without massive imports. With a average of 1 billion people, this presumes around a dozen very developed systems, each surrounded by around one hundred less developed systems. The population and utilization of planets is less important, though terraforming gives a reason for a large population for a system. Now, if you have a higher average level of development, you will end up with a wealthier society.

For example, the Sol System might be able to sustainably support around 1 trillion biological sapients, primarily in gigantic orbital structures. A 100 km radius and 1000 km long rotating habitat is well within TL10 capabilities, and such a habitat could hold 5 billion people in comfort. With 200 such habitats, you end up reaching 1 trillion people, and have an economy for the Sol System alone being $67 quadrillion per year (and you are only a K1 civilization).

[Fred Brackin]

Originally Posted by AlexanderHowl

For example, the Sol System might be able to sustainably support around 1 trillion biological sapients, primarily in gigantic orbital structures. A 100 km radius and 1000 km long rotating habitat is well within TL10 cap

What would it need all those bio-sapients for except to pay taxes so very large spaceships can be built? Even with artificial wombs seeing 1 trillion toddlers through the terrible twos is a lot of work.

[Pomphis]

Originally Posted by AlexanderHowl

If a system has less than 500 million people, it will likely have difficulty maintaining a TL10 society without massive imports.
... For example, the Sol System might be able to sustainably support around 1 trillion biological sapients, primarily in gigantic orbital structures.

In an interstellar empire a world doesn´t have to maintain a complete TL10 society on it´s own. Why shouldn´t many worlds be equivalents to luxembourg, puerto rico, singapore, new zealand, etc?

And where do all those people come from? We are TL8 and all wealthy TL8 nations can maintain populations only by immigration. The empire may have to produce bioroids/clones just to keep populations stable.

[AlexanderHowl]

Of course. People in wealthy nations have fewer children because children are expensive, so they tend to devote more resources to fewer children. With proper social supports though, a wealthy society can increase birth rates by 25% (as seen in France).

In addition, increasing longevity will likely increase reproductive years. At TL10, society can easily engineer parahumans with Early Maturation 2, Extended Lifespan 2, Longevity and give them nanosymbiotes that would give them an additional Extended Lifespan 1, meaning that reproductive years would go from an average of 30 years to an average of 345 years, allowing them to have multiple generations of children.