https://edition.cnn.com/2020/06/15/world/intelligent-civiliz...
So far, we only have proof that civilisations can exist for at least several thousand years if you consider the Human civilisation.
But so far, the data on civilisations capable of interstellar communication doesn't look too promising. The "unless they wiped themselves out" is the big question. Are we behind or in front of the Great Filter.
The universe is ~15B years old, and we expect it to keep forming stars (as good as any of a metric for “hospitable to life”) for another trillion years. In other words, we’re in the first percent or so of the lifespan of the universe.
Doesn’t seem too crazy that if we start conquering the stars, we might be the first ever species to do so.
(And if history is any indication, we’ll probably cause some sort of galactic global warming in the process, that all starfaring species after us will curse us for)
The only serious theoretical FTL paper (Alcubierre drive) I know of requires exotic matter (negative mass) or energy equivalents of entire planets so if we ever manage to build it, I think that's a fair bet.
Another paper calculated that the space-time bubble created by the Alcubierre drive would capture radiation and particles along its path, creating a gamma ray burst at the destination in a large cone in the direction of travel. Meaning, we'd be sending deadly bursts of radiation all over the galaxy that would wipe out all carbon based life for tens or hundreds of light years every single jump. A rogue actor or a miscalculation could wipe out significant fractions of our own civilization.
The kind of colonization you’re describing requires exponential growth, but at least on Earth we’ve seen that birth rates dropping in developed nations.
It's also likely that a self sufficient, long-term thinking planetary civilisation would limit their population to a certain size, to not needlessly exploit the resources that they have available.
In fact, the only motivation that makes sense w/o exponential population growth is a militaristic/defense oriented one, which would also favor the dark forest theory.
Suppose it turns out that there is nothing faster for interstellar travel than rockets or light sails. No wormholes stabilized with exotic matter. No warp drives. No other tricks.
I'm not sure in that case that those long lasting civilizations would bother trying interstellar colonization. The round trip transport time between the home world and colonies would be so long that it is hard to come up with any economic benefit establishing such colonies provides to the home worlds.
If medium human life were only 4 weeks, nobody would find funding for a 1 year colonization trip across a different continent. You wouldn't find a crew when it'd take one generation just to cross the atlantic once.
I think it's similar here. With future (bio-)technological improvements, we might live for hundreds or thousands of years. Suddenly individuals would start thinking really long term...
At one point every niche of the solar system will either be declared a national park/treasure, or mined, filled with real estate developments, etc. We'd run out of space and some rich folks would meet on one of the private moons of Jupiter (like how there are private islands today) to discuss a venture towards another star.
Let’s just hope, for the sake of any beings already on other planets, that you are right.
History here on Earth suggests that long journeys are not a sufficient obstacle for exploitation.
This is really, really unlikely to be true, for all kinds of reasons.
There's a huge difference between colonising a galaxy - which assumes some kind of uniform culture, and common strategic goals - and simply throwing more or less living/sentient stuff around a galaxy and hoping some of it sticks.
We've gone from barely being noticeable on Earth to being in danger of being responsible for a planetary extinction event in around 12,000 years.
We know nothing about building a stable culture that can last for millions of years. It's unlikely any sentient species will be able to learn that skill without making a lot of mistakes - some of which will be terminal.
So galactic colonisation requires a lot more than solving the mechanics of transportation. And the "few million years at 0.1c" estimate is going to be Not Even Wrong.
We colonized the whole planet without that. Likewise a locust-like swarm of colonizing ships without any central control or common culture would also be a possibility.