[Space] The Galactic Empire according to GURPS Space

[AlexanderHowl]

A population of one quintillion biological sapients is rather extreme. Even a developed and wealthy system is unlikely to have much more than 10 billion people, as people will immigrate is slightly less wealthy systems instead of living in poorer sections of a wealthy system, and the system average will likely be more on the order of 1 billion people. With 10 million star systems in the majority of the galactic polities that we have discussed, that suggests a population of 10 quadrillion people.

At 10 quadrillion people, you will still have a massive economy. At TL10, the average income of $67,000 per year would create an economy of $670 quintillion per year. Even if terraforming an Ice or Ocean planet costs a total of $1 quadrillion, the society could easily afford to finance 6700 per year, meaning that terraforming would be quite widespread (if it takes a 1,000 years, there may be 6.7 million in various stages of completion, with 6700 being habitable every year). If we assume a 0.067% increase in worlds every year, it would take around 25,000 years (assuming a 1,000 year lag) for one habitable planet to become 10 million habitable planets through terraforming.

[David Johnston2]

Originally Posted by AlexanderHowl

I am skeptical that any Garden planet will be compatible with Earth life, just because there will be no commonality between its life and Earth life. e.

I'm skeptical that interstellar empires would even be possible. In fact I'm skeptical that interstellar travel would even be a thing. So I let such things slide particularly since all those Garden Worlds may have started out as Barren World before we panspermiaed the heck out of them.

[Michael Thayne]

I wonder about the possibility of having The Empire adopt a not-particularly-flat organizational structure to handle whatever's going on in an individual system, but use an extremely flat structure above that. Like each system has a Head Tax Collector following an extremely standardized playbook, and the theory is that they don't need to coordinate much with each other, so the next layer of the hierarchy might have 1 person supervision 100 Head Tax Collectors. Of course this could cause problems—what about situations where they do need to coordinate? And lax supervision could encourage corruption...

[dcarson]

Originally Posted by Black Leviathan

I think population growth isn't a guarantee, especially in a colonial stage. If we reach a new world by generational ship there will likely be very extreme taboos against having more than two children. New colonies won't be bountiful, scarcity could be an issue that would discourage births. Hard work would be another problem. Colony life wouldn't likely leave much time for maternity leave or staying home to raise the children. Even once the garden blooms and life becomes less strenuous there's no guarantee that generations of birth conservation won't have changed cultural attitudes about large families. Colonial worlds could very possibly fail for a lack of breeding.

If it is a generation yes the taboos against large families will need to be overcome. However scarcity and hard work create large families because you need the labor, it is the well off that have few kids.

[AlexanderHowl]

Originally Posted by dcarson

If it is a generation yes the taboos against large families will need to be overcome. However scarcity and hard work create large families because you need the labor, it is the well off that have few kids.

Even in the USA, immigration was usually more of a driver of population growth than births because adults are more valuable laborers than children. In a TL10+ society, I am not sure you can have a labor shortage. Even if you are only using NAI to run robots, humans are capable of supervising a lot of robots, and children would be relatively worthless supervisors.

[Rupert]

Originally Posted by AlexanderHowl

Even in the USA, immigration was usually more of a driver of population growth than births because adults are more valuable laborers than children. In a TL10+ society, I am not sure you can have a labor shortage. Even if you are only using NAI to run robots, humans are capable of supervising a lot of robots, and children would be relatively worthless supervisors.

On the other hand, assuming that all the wealth isn't in the hands of the 1%, people will be wealthy enough to be able to afford children if they want them. So the question is how many children do people feel the need to have when they are all comfortably well off, and have no economic need for offspring, yet won't suffer any hardship should they choose to reproduce?

[(E)]

There might be economic and technological conditions where people work until their 50s or 60s and then drop into semi retirement and steadily have children at a slow rate for many years utilizing all the technology available to assist in the process.

[Taneli]

Just saying that having your entire galactic societys entire economic output focused into one single project does not sound to me as being easily afforded. War effort on the USA was around 40% of the GDP in 1945.

Originally Posted by AlexanderHowl

A population of one quintillion biological sapients is rather extreme. Even a developed and wealthy system is unlikely to have much more than 10 billion people, as people will immigrate is slightly less wealthy systems instead of living in poorer sections of a wealthy system, and the system average will likely be more on the order of 1 billion people. With 10 million star systems in the majority of the galactic polities that we have discussed, that suggests a population of 10 quadrillion people.

At 10 quadrillion people, you will still have a massive economy. At TL10, the average income of $67,000 per year would create an economy of $670 quintillion per year. Even if terraforming an Ice or Ocean planet costs a total of $1 quadrillion, the society could easily afford to finance 6700 per year, meaning that terraforming would be quite widespread (if it takes a 1,000 years, there may be 6.7 million in various stages of completion, with 6700 being habitable every year). If we assume a 0.067% increase in worlds every year, it would take around 25,000 years (assuming a 1,000 year lag) for one habitable planet to become 10 million habitable planets through terraforming.

[David Johnston2]

Originally Posted by AlexanderHowl

Even in the USA, immigration was usually more of a driver of population growth than births because adults are more valuable laborers than children. In a TL10+ society, I am not sure you can have a labor shortage. .

Of course you can. Early on in the colonization of a planet before you have enough industry to start producing large amounts of robots you're going to need actual people. After you produce large amounts of robots you can of course dispense with all the people, but Galactic Empires don't do that since if they did there would be no reason to colonize anywhere.

[Bengt]

40k's worldbuilding is like 100% rule of cool. There will always be plenty of planets for Exterminatus, plenty more where millions of guardsmen can be recruited for the meat grinder, people have lived for thousands of years on planets that are desolate wastelands or covered by mines and factories, etc just to properly underline the grim darkness of Grimdark.

Likewise tech level is all over the place, and sometimes outright magic. Sure some of this explained with lost/rediscovered tech but it flips back and forth at an alarming rate from story to story.

So explaining 40k with any kind of rigour would be quite the challenge. :)