Space travel, and the possibilities of interstellar migration

[Spider-Vader]

Well, some would say they're already here (UFO's), watching us. And really, it makes sense. Any sufficiently advanced alien civilization should be able to find us easily. We're the loudest planet in the neighborhood, and the only one with neon lights. I don't think Mass Effect ever touched on that. Star Trek did.

Yeah ME never touched on that. Since in ME, the way people get around the galaxy is through "Mass Relays" & the one near our solar system was undiscovered until humans found it.

I believe in other intelligent life in the galaxy, but I don't believe that they've visited Earth. You think they'd make their selves known to try & advance our civilization.

 

[Thundercrack85]

Yeah ME never touched on that. Since in ME, the way people get around the galaxy is through "Mass Relays" & the one near our solar system was undiscovered until humans found it.

I believe in other intelligent life in the galaxy, but I don't believe that they've visited Earth. You think they'd make their selves known to try & advance our civilization.

Personally I don't. The height of the modern UFO phenomena was in the late 40's and early 50's. Let's assume (for the sake of discussion) that some of those flying saucers were of extraterrestrial origin. They could literally see the atomic bombs going off from space. No advanced civilization would look at that (not to mention all the other crazy crap going on in the world... a lot of which continues to this day), and say "let's go down there and teach them about quantum mechanics and anti-matter".

It would be like us going to the most backwards part of Dark Age Europe and trying to educate the local, plague-riddled serfs about personal hygiene and bacteria.

 

[Edguy]

Considering we're finding "potentially" habitable planets right now, and we have yet to go to Mars (in person, anyway), I would image that an alien species that has mastered interstellar travel would map out most habitable planets in their stellar neighborhood in a fairly short period of time. If they've been around for thousands of years (and why not), they could have mapped a good chunk of the galaxy.

Earth has had complex life on it for a very long time. So, for all we know, civilizations could have been observing Earth for hundreds, thousands, or even millions of years.

If you have a catalogue of habitable planets, you'd probably notice quickly if one of them started broadcasting.

There are several hundred billion stars in Milky Way. Even if they had technology to travel instantaneously around the galaxy, which is far beyond what even theoretical scientists can imagine, mapping all those systems would tale many millenniums, if not more. We're pretty much a needle in a haystack..
And that is assuming there are aliens out there who have mastered FTL travel, which, like I said, is far beyond even our engineering imagination. For an alien species to become so technologically advanced, unless they find some shortcut that we haven't yet, then I think they'd also be socially advanced beyond our understanding. They sure as hell wouldn't be flying saucers and kidnapping crazy people..

 

[Thundercrack85]

Travel across the galaxy? There could be aliens down the block. If we're finding planets around Alpha Centauri and Tau Ceti (one literally, next door, the other stone throws away on an interstellar scale, some even potentially habitable), there could be alien civilizations all around us. And we've only started really looking.

As for them being socially advanced beyond our understanding… what does that mean? How hard is it to be more socially advanced than a pack of apes who kill each other every day?

Also… we are imagining FTL travel right now. Obviously still beyond our means, but we're partially to blame for that ourselves, wasting all our resources on trivial things, and killing each other. It's rather sad, and telling that most our technological advances haven't been made for the sake of societal advancement, but so that we can better kill each other (our nukes, our rockets, etc).

 

[Piper Maru]

The Known Universe by AMNH
[YT]17jymDn0W6U[/YT]

 

[Thundercrack85]

I want to just reiterate a point. There could be an alien civilization, a million years ahead of us (or behind us), ten lightyears away, and we would not know.

We are very blind.

 

[Edguy]

The planets you talk about are just within the habitable zones of their stars, that doesn't mean there's any reason to believe there's life on them, much less intelligent life. Odds say that there's life in our galaxy, perhaps even intelligent, but not within the tiny little spec that we can investigate with any accuracy. And, I believe there's just 7 or so star systems within a 10LY radius from Sol.

And about FTL, no. That's just theoretical speculation from Discovery etc., made out to sound plausible for casual viewers. Traveling FTL is impossible according to the theory of relativity, and wormholes or hyperspace or warp space or otherwise "bending" space-time whatever has no practical basis. It's all educated speculation. Even accelerating to velocities high enough to reach the nearest stars within a lifetime is practically a no-go at this point. Sorry if I sound like a killjoy, just saying it like it is.

 

[Thundercrack85]

I know. I can read. But, you're missing my point. The fact that we've found a Venus in Alpha Centauri (and now a plane it in the habitable zone of Tau Ceti) would suggest that rocky planets like our own are very common, and under the right conditions could be like our own planet, or even one rather different, but still capable of supporting life. I don't think Drake ever figured habitable moons into his equation. I don't know about 10, but there are thousands of stars within a 100 lightyear radius of us. 100 lightyears is nothing in interstellar distances.

As for how interstellar travel is done, I will freely admit that the technical details of the Alcubierre drive are lost on me (got good grades in physics, but not my major). Although as I understand it, it's really not really FTL, so much as space-time manipulation (cheating the universal speed-limit). In any event it seems to have convinced a lot of physicists that it's feasible, if impossible with our current technology. But I rather doubt we're done with technological breakthroughs.

Course, if you have to rule that out, I suppose slower than light travel is still possible, with advanced robotics. Takes a damn long time, but what do robots care.

Either way, point stands. Aliens could be down the block, and we'd have no clue.