I was talking about traveling between galaxies, my understanding is there's essentially nothing between them: no asteroids to mine. So you'd need to bring everything you might need in advance. But maybe I'm wrong, maybe there is a decent amount of debris floating between galaxies?
> They could literally just be a bunch of machines that "live" in space. Floating around from place to place, grabbing resources from asteroids as they go by.
Whenever I think of what an advanced civilization would look like, I picture something like this (though not necessarily just machines). Something semi-nomadic, an entire civilization of ships in a big fleet, wandering together through the galaxy, stopping at various systems to gather some resources or explore the planets. Maybe the fleet breaks up and goes in different directions for a time, and rendezvous later.
>I was talking about traveling between galaxies, my understanding is there's essentially nothing between them: no asteroids to mine. So you'd need to bring everything you might need in advance. But maybe I'm wrong, maybe there is a decent amount of debris floating between galaxies?
The current thought now is that there's likely quite a few "rogue planets" out there, and other asteroids that haven't gotten captured by a star. However, the density of such things is likely to be so low, and you won't know until you get there what they're composed of, so it seems like a bad idea to plan a trip assuming you're going to stop at a bunch of asteroids and rogue planets to pick up supplies; you'll easily make your trip far, far longer. Don't forget also the big problem in long-distance space travel is speed. If you want to get to a particular star system, you need to get up to speed and stay there until you're ready to decelerate. You can't afford to slow down and stop at a bunch of rocks along the way, and you'll be going far too fast to capture the small ones. Most of your fuel will be used in acceleration and deceleration, so you can really only do that once most likely.
>Whenever I think of what an advanced civilization would look like, I picture something like this (though not necessarily just machines). Something semi-nomadic, an entire civilization of ships in a big fleet, wandering together through the galaxy, stopping at various systems to gather some resources or explore the planets. Maybe the fleet breaks up and goes in different directions for a time, and rendezvous later.
That doesn't sound like an "advanced civilization" at all, that sounds like a nomadic gang. An advanced civilization will value stability, and stay on their home planet(s) where all their infrastructure is located. They may very well send out exploratory missions, but those nomadic wanderers will not be the civilization itself, just one small part of it.
> An advanced civilization will value stability, and stay on their home planet(s) where all their infrastructure is located
My thoughts were that a sufficiently advanced civilization would desire exploration, both for resources and scientific advancement. And you don't want your people spread out too far (for some definition of far), for a variety of reasons, the biggest being the consequences of the delay in communication and travel. For instance, scientists in different solar systems would find in next to impossible to collaborate: it could take years for news of one group's findings to reach the other, at which point they may very well have independently discovered the same thing, which is inefficient. Also, if one of the systems is attacked, or has some sort of crisis that requires assistance (plague, natural disaster, etc), the rest of the civilization would be unable to react in a timely manner. In short, it's safer to stick together.
Therefore, it would make a lot of sense to put your whole civilization into a fleet of ships with all your infrastructure (or maybe a single giant ship, Death Star sized), and move around. You could stay in a single solar system for a few millennia mining resources, or hop around looking for life.
Sticking to one place or a few nearby places is also an option, but I think it lacks certain advantages a fleet civilization would have.
For instance, scientists in different solar systems would find in next to impossible to collaborate: it could take years for news of one group's findings to reach the other, at which point they may very well have independently discovered the same thing
Even on Earth, where the latency between devices on opposites sides of the planet is measured in hundreds of milliseconds, this is true.
The ten closest stars to Earth are within about 10 light years distance. While two way communication would be impractically slow, sending a continuous stream, UDP-style, to another colony would probably do the job sufficiently well.
>Also, if one of the systems is attacked, or has some sort of crisis that requires assistance (plague, natural disaster, etc), the rest of the civilization would be unable to react in a timely manner. In short, it's safer to stick together.
This is incorrect. This is the "all your eggs in one basket" problem: if you have a big crisis in your civilization, you don't want everyone in one place, because your whole civilization could get wiped out. A civilization this advanced is likely also a very large civilization, so it makes more sense for it to have different parts in different places, just in case.
As for communications, as the other responder pointed out, a continuous transmission, assuming the data rate is high enough, will help keep the different locations in sync. Who cares if scientists independently discover things? Hopefully a civilization that advanced won't be so worried about patent rights.
As for "hopping around" looking for life, you'll do a whole lot better keeping your civilization in one place (or a few permanent locations better yet) and sending probes or exploration teams to a bunch of different places at once. Moving your entire civilization to only one star system at a time would be horribly slow, and sticking everyone in a giant death star means your energy requirements for transporting your civilization between stars would be ridiculous.
A fleet civilization wouldn't have any advantages besides mobility. You only need that if you have something you're trying to get away from, or have a well-founded concern that staying in one particular place could be dangerous. For Battlestar Galactica, it made sense because they were constantly being chased by the Cylons, and even then, the show did a pretty good job, at least at first, of showing what a PITA it is constantly being on the move. For a large, highly advanced civilization that doesn't have a bunch of genocidal robots chasing it, I just don't see how there's any advantage to remaining highly mobile. Mobility requires a lot of energy and greatly limits you in other ways. For a modern analogy, look at people today who live in RVs. Sure, they can drive their whole home away quickly and don't have to worry much about packing up to move, but they don't have much space, their home is easily damaged compared to normal dwellings, and it costs a lot to move it (because of the poor fuel economy). The only way living in starships makes any sense is if energy is basically free for you, which includes having a way to store immense quantities of it, because you'll need a lot when you're between stars.
Hmm your arguments make sense. I think I was overvaluing mobility, because I figured once reaching a post-scarcity society exploration would become the top priority.
My only other point is that the continuous transmission idea only works up to a point. Two populations that sufficiently far (I'd say hundreds of light years, but it could be thousands or millions of light years) apart are essentially different civilizations, because their societies would drift out of sync. Think about how much our culture, our language have changed in the past few centuries, and the rate of change in our society in only increasing. Extreme longevity or immortality might slow down the rate of change, but I'd argue that it wouldn't stop completely.
I guess my point is that civilizations have a maximum radius over which they can function, otherwise societies will drift apart until they are essentially distinct.
That's something I don't see much on these forums! Thanks!
>I think I was overvaluing mobility, because I figured once reaching a post-scarcity society exploration would become the top priority.
I know Star Trek isn't the most realistic TV show in the world, but I do think it (esp. TNG, esp. seasons 3+ because 1-2 sucked!) did a pretty fair job of showing what a post-scarcity society would look like, though to be fair energy was somewhat limited, but not that much.
In the show, most people/beings in the Federation lived on their home planets, or on colonies. There were a LOT of colonies; it seemed they were shown or mentioned every other episode. Most biological beings, assuming they evolve on a planet, and don't upload their minds into androids or something, are probably going to want to continue something like the lifestyle their ancestors had. In addition, there's huge logistical advantages to having stable facilities on planets. Where does the Federation build its starships? On planets, or in orbital construction yards (most likely, the components are largely made planetside, especially small but valuable ones like their computer equipment, and the ships are assembled in orbital shipyards). Where does the Federation mine the resources needed for ships and other stuff? Probably largely on planets and moons, though not necessarily the ones they live on, but the mines are probably very long-term and stable. And where does the Federation get the antimatter it needs to power its ships? According to the technical manual IIRC, they synthesize it from solar energy somehow, since antimatter is not naturally occurring in this universe. So all the infrastructure their society depends on for exploration (which is what many of those starships spend their time doing) is located in relatively fixed locations. Plus, the number of citizens in the Federation is surely enormous (they have thousands of members IIRC, and Earth alone probably has at least 5 or 10B by that time, depending on how many perished in WWIII and how many left the planet for colonization and of course the birthrate). The number of Federation citizens living full-time on starships is surely a tiny, tiny fraction of the total number.
>Two populations that sufficiently far (I'd say hundreds of light years, but it could be thousands or millions of light years) apart are essentially different civilizations, because their societies would drift out of sync.
That's true, but it really depends on the size of the civilization. If our civilization grew to span the nearest 50 star systems, for instance, they'd still all be within 16 light-years [1]. That's a pretty good-sized civilization IMO, and 16 years isn't that long to wait for a news about what's going on the homeworld (though it also means it's about 32ly between the farthest two colonies). A civilization spanning thousands or millions of ly would either be an incomprehensibly enormous civilization, or one which is really picky about which star systems it bothers with.
If you expand that radius to 30ly, now you're looking at probably hundreds of stars. Couple that with the immortality you mention, and assume very stable governments (since a civilization with governments like ours is not going to be spanning multiple star systems, and wouldn't even get far off the planet) and I do believe the rate of change will be much slower so that it's not that big a deal if you don't learn about some interesting news or new music or something from one of the other colonies until it's 50 years old. And don't forget, we consider ourselves (humanity) as having a singular civilization, but how in-sync are we between different nations? Not that much; we don't even speak the same languages much of the time. Most likely, in such a civilization, the different worlds would have different cultures, and there's only be so much interconnection between them, mostly for trade but also probably tourism and such. But I guess now we're getting into an argument over the exact definition of "civilization"; do we have a singular one now, or are the US and China two separate civilizations with trade and cultural exchange? What about centuries ago when communication was all by hand-carried letter or word-of-mouth?
> They could literally just be a bunch of machines that "live" in space. Floating around from place to place, grabbing resources from asteroids as they go by.
Whenever I think of what an advanced civilization would look like, I picture something like this (though not necessarily just machines). Something semi-nomadic, an entire civilization of ships in a big fleet, wandering together through the galaxy, stopping at various systems to gather some resources or explore the planets. Maybe the fleet breaks up and goes in different directions for a time, and rendezvous later.