Space expantion does not need to be planetary

[Teleros]

Erm it should still hold an orbit as long as it's spinning around the star, it'll even negate its own weight and reduce stress on the structure if it's spinning at the right speed.

Aside from what Rubidium noted, a few discussions about it online for you:

http://physics.stackexchange.com/questions/41254/why-is-larry-nivens-ringworld-unstable
http://www.popularmechanics.com/space/deep-space/a11183/could-we-build-a-ringworld-17166651/

Larry Niven actually addressed the issue of drift in The Ringworld Engineers after some of the smarter fans realised the problem .

 

[Deaghaidh]

space being so empty, at some point even a mostly orbital society will need inputs from planets, no?

and IIRC, a Dyson sphere would require more materials to construct than the total amount of mass in the solar system, so you'd still need to strip mine some other systems. Which is something I totally support being an option in game.

 

[Teleros]

space being so empty, at some point even a mostly orbital society will need inputs from planets, no?

Uhm, well there's lots of asteroids and such out there don't forget. Other materials may be found on planets or moons with low surface gravity, which makes it easier to get the stuff you want off the planet (unlike, say, Earth).

 

[Deaghaidh]

Uhm, well there's lots of asteroids and such out there don't forget. Other materials may be found on planets or moons with low surface gravity, which makes it easier to get the stuff you want off the planet (unlike, say, Earth).

Sure, but you'd still need some body that the space station would need to be associated with, instead of just floating about wherever it wants. If that makes sense.

So you could have a pleasant habitat with all your processing and such orbiting over a world with a toxic atmosphere but important resources. Much more cost effective than terraforming I expect. Many of these outposts and a few garden worlds (terraformed or natural) could make a good space empire. The idea of them being relocatable would be fun, as it gives you the option to relentlessly harvest your neighbors and move on like a plague of locusts.

 

[womble]

Once you're at the stage of translight travel, you're not going to need very much that takes planetary processes to produce. Raw materials are easier to get out of orbital objects than out of mines; organics can be grown on habitats. Building an orbital-circumference Ringworld, though, will pretty much strip the local system, just for mass (unless you've got energy -> mass direct conversion nailed (which, to be fair, you probably have to in order to build the thing), and as has been said a Dyson Sphere of 1AU diameter could take more mass than than a solar system contains, including its primary...

You might want or prefer some things produced on planets. They'd be luxuries, and not core economic product.

 

[Teleros]

Sure, but you'd still need some body that the space station would need to be associated with, instead of just floating about wherever it wants. If that makes sense.

That makes sense for the game, but IRL there's nothing to stop you setting your own orbit at a distance of your own choosing around a star or other celestial object, even if it's far from anything useful.

 

[Aegrim]

Aside from what Rubidium noted, a few discussions about it online for you:

http://physics.stackexchange.com/questions/41254/why-is-larry-nivens-ringworld-unstable
http://www.popularmechanics.com/space/deep-space/a11183/could-we-build-a-ringworld-17166651/

Larry Niven actually addressed the issue of drift in The Ringworld Engineers after some of the smarter fans realised the problem .

Finally checked those links out, that makes perfect sense thankyou.