Alien Life, Interstellar Travel, and Million year Civilizations

[Reynard]

I am spinning this out of the "Today I Learned" thread because I think it is worthy of its own dedicated discussion.

Do you think life is common in the universe? Rare? What kind of life? What about intelligence? What about advanced civilizations? Do you think humanity will one day spread throughout the galaxy? If so, in what capacity and how long will it take? Have you read or otherwise learned about specific hypothesis on the subject you embrace or reject?

Let's talk about Life, The Universe, and Everything.

 

[Reynard]

For my part, I think life is basically inevitable based on chemistry, and complex life is probably equally common (though it appears to take time). I don't know that "intelligence" as we think of it is particularly special, and may or may not even be long term adapative. Nor do I think there is any reason to believe we, or our place in the galaxy, is particularly unique, so I expect intelligent life to be relatively common.

However, I do not think interstellar travel is easy or even necessarily possible on any timescale that would result in what we would call an "interstellar civilization. We don't really know the effects of long term space travel on biology or even machines, and we also don't really know any way to get speeds that make interstellar travel short enough to bypass those issues. Intelligent life may be stuck on islands throughout the cosmos with no real way to communicate, let alone travel and interact.

I also don't see how humans or anything like us could manage the kind of continuity of civilization required to get to the real "sci-fi" tech levels. Biological beings are driven by needs and desires that do not mesh with thinking about million year dynasties.

 

[Autumnal]

I don’t think there is a human destiny out among the stars, nor that we’ll build an interstellar civilization with or without a grand destiny. I think, rather, that long-term humanity will tend to cluster tightly, to minimize communication legs, with support systems like renewable power spread out and a lot of space returned to natural processes. Settling elsewhere in the solar system, maybe, but unless Alcubierre drives or something work out, I don’t see us going light years.

I’m agnostic shout true general AI, von Neumann machines, and such. Maybe? If so, maybe we spread mechanical footyprints around.

 

[Reynard]

.

I’m agnostic shout true general AI, von Neumann machines, and such. Maybe? If so, maybe we spread mechanical footyprints around.

The thing is, even for machines, highly energetic particles are a thing. Space isn't actually empty. And the faster you go, the more shielding you need, and so the more energy you need to get up to speed. But the slower you go, the more time there is for just natural entropic elements to wreak havoc. It's a hard problem no matter how you cut it.

 

[Autumnal]

It really is. I’ve seen arguments that longer, slower journeys might end up taking less damage overall. I’m not competent to do the calculations myself, but I find the idea interesting.

 

[MarkB]

It's a big galaxy (let alone universe), there's probably something out there somewhere. But with a sample size of one, it's very difficult to tell just how rare or anomalous self-replicating chemical structures that tend towards increased complexity and diversity over successive generations actually are, let alone the particular twisting path that ultimately leads to tool-building, problem-solving intelligence.

Whatever the rate of occurrence is, that end result (or intermediate stage, or ecological dead end - we're still walking that path, so who knows where it leads next for us) probably looks very different depending upon both environment and genetics, so the chances of us or our descendants ever seeing a species elsewhere that does "civilisation" in a form that we can recognise or acknowledge are pretty vanishingly slim.

 

[Ryujin]

The thing is, even for machines, highly energetic particles are a thing. Space isn't actually empty. And the faster you go, the more shielding you need, and so the more energy you need to get up to speed. But the slower you go, the more time there is for just natural entropic elements to wreak havoc. It's a hard problem no matter how you cut it.

Something like "magnetic shielding" to protect against high energy particles, so energy production is more important than straight massive metal shields?

I have to wonder if supra-light travel is possible, by any means. "Folding space", etc. as a cheat, sort of thing. Getting to a fraction of the speed of light at more than a few Gs and you start to need things like "inertial dampers." Doc Smith's "intertialess engines."

Is there life out there? Intelligent life"? To my mind, definitely.

 

[Reynard]

It's a big galaxy (let alone universe), there's probably something out there somewhere. But with a sample size of one, it's very difficult to tell just how rare or anomalous self-replicating chemical structures that tend towards increased complexity and diversity over successive generations actually are, let alone the particular twisting path that ultimately leads to tool-building, problem-solving intelligence.

Whatever the rate of occurrence is, that end result (or intermediate stage, or ecological dead end - we're still walking that path, so who knows where it leads next for us) probably looks very different depending upon both environment and genetics, so the chances of us or our descendants ever seeing a species elsewhere that does "civilisation" in a form that we can recognise or acknowledge are pretty vanishingly slim.

I think that any biological organism that develops tool use is going to "do civilization" in a way we can recognize, simply by virtue of the needs being essentially the same. That's not to say that we will be able to "get" their way of thinking or language or philosophy, but i think we will be able to look at their clusters of dwellings and be able to say, yeah, that's a town analog.

 

[dragoner]

Yes, very common over the universe, from a scientific basis, life is just chemistry. It is just that time, and distance are so immense it is difficult for us to see it, and we really don't even know what we are looking for. I mean like if expanding to another star system is just building a space station there, we really aren't going to be able to see something like that without better resolution telescopes.

 

[MarkB]

I think that any biological organism that develops tool use is going to "do civilization" in a way we can recognize, simply by virtue of the needs being essentially the same. That's not to say that we will be able to "get" their way of thinking or language or philosophy, but i think we will be able to look at their clusters of dwellings and be able to say, yeah, that's a town analog.

Assuming that they need to live 'in' something, and that thing is anything we would recognise as a building, that such buildings are permanent structures, and that we can differentiate between buildings constructed by intelligent beings and those built by other creatures. Do ants have a civilisation?