/sci/ - Science & Math

>>9945965
If our pattern of advancement is typical, then odds are one discovers biological immortality (or at least extreme longevity), before one figures out interstellar colonization. And, indeed, you pretty much require the former for the latter.

This means you need a population cap.

Any civilization that achieves extreme longevity, and doesn't start defining its biological drives, rather than be defined by them, is going to burn out its biosphere before it escapes it. Assuming your non-biological technology has continued at a similar pace, there is no advantage to a larger population, even when it comes to war, as you can build superior machines faster than you can breed.

Thus, any such advanced civilizations are going to be small, extremely forward thinking, and extremely efficient. A near immortal civilization that defines its own drives, isn't going to fall into the unsustainable trap of attempting to populate the entire galaxy.

So, at best, each such civilization makes two or three population capped interstellar colonies to prevent extinction at the hands of cosmological disasters. There's nothing to be done, in terms of colonizing, to further ensure the survival of your civilization beyond that point (assuming FTL travel is not possible). Such tiny super-efficient colonies are not going to be detectable by us. No need for Dyson spheres or other such megastructures. They'll likely have a much smaller footprint than our own civilization, still slaved to its biological drive of infinite expansion.

But we can't see shit anyways. It could be full on Star Trek out there, and we wouldn't be able to tell with our current observational infrastructure.

I still find it more likely that intelligent life is just rare as fuck, and civilizations like ours appear, on average, maybe once for every few hundred galaxies, but no discovery in the past 10 years has made it less likely that we aren't alone here. Indeed, quite the opposite.

>>9866167
>>9866170
Still kinda neglecting the fact that to another similar telescope, it'd be perfectly visible.

We've only had huge cities with night lights for roughly 200 years. Anything further away than that hasn't seen us yet, and, at best, knows there's life on the planet. Given how remote our location is, it maybe there's simply no detector that close.

So, Dark Forest could still easily be a thing - and it could very well be we'll find out the hard way, depending on what the criteria for potential threat is. It may also be that the kill device is already in route.

>>9328357
>without saying anything about interstellar travel
>if there is no interstellar travel, there is no Fermi paradox.
This... The whole premise of the Fermi paradox is that some species bent on infinite expansion should have colonized the whole galaxy by now. No interstellar travel = no Fermi paradox. (Though I tend to agree with the biological immortality possibility [>>9328942]
, though possibility #1 seems more likely.)

It's not about the lack of radio signals, because pic related is actually an extreme exaggeration, when you take inverse square into account. The lack of Dyson spheres is stupid, because Dyson spheres are stupid, and if you aren't engaging in interstellar travel, seems you'd be much less apt to need them.

>>9256863
Are there people seriously using the lack of alien communications of evidence for anything?

If there was another civilization, putting out the same amount of radio communication as we do, orbiting any planet further away that Jupiter, we wouldn't detect it... Cuz Inverse square is a bitch.

The Fermi paradox doesn't come in due to that - it comes in due to the fact that we haven't been colonized yet - but it assumes that a species, and every colony that species makes, is bent on infinite expansion, and has been, for millions of years. All this, despite knowing full well it isn't sustainable, and probably having had to put a cap on that shit to survive long enough to become space faring to begin with, and probably needing to be biologically immortal to boot, which in itself, requires they put a cap on that shit.

>>8992570
Because there's a fuckload of stars.

Turns out most of them have planets.

Turns out our star isn't even the most likely type to have rocky planets in its habitable zone.

Turns out the type that is most likely is a hundred times more common and lasts a hundred times as long.

Turns out we're way out in the rural boonies in terms of our own galaxy, with a whole lot more stars and solar systems in suburbia and the city.

Turns out there's a fuckload more galaxies than we ever thought.

Turns out a lot of them have already red shifted forever beyond our view. Judging by the CMB, maybe even most of them.

Turns out the elements that make up life are pretty damned common, all among the most common in the universe.

Turns out even asteroids have nucleotides on them.

...and all of this has been true in all of the universe, well before our star was even born.

So yeah, it is kinda hard to believe we're the first intelligent life in the universe. I mean, yeah, we might be among the first 1% - but there's probably a lot of company in there.

Now if you want to argue whether or not there's any in the same galaxy as us so we can actually meet them some day, that's another thing... But there's at least 10^24 opportunities for this to happen, so the odds of it not happening again somewhere else - pretty damned slim, as that'd be a lot of lottery winners.

>>8684875
>If they existed in recent history, we'd probably pick up some radio.
Actually not a thing... There could be a civilization similar to ours in our own solar system, and unless they were pointing a SETI like program right at us, we could conceivably miss it. Similarly, there's no way we're going to pick up any nearby radio signals from other solar systems only intended to be received within the terrestrial bodies that broadcast them, and even for planets within those same system, unless, again, they put in a significant investment to deliberately broadcast right at us - which, given our own history, is pretty suicidal for our dumb asses to be doing.

Inverse square is a bitch - ain't no one picking up Hitler's speech during the Olympic broadcast. Never mind the fact that we've all but entirely switched from analog to digital ourselves, masking our radio footprint even further, and we're not even trying to hide.

>>7649019
Life could be on every other planet out there. It could be on half the planets and asteroids in our own solar system - and we wouldn't know it.

As for the Fermi Paradox... Why we don't detect other civilizations using radio waves... The damn universe has been capable of supporting such civilizations for billions of years. We've been broadcasting radio waves for just over a hundred, SETI for about half that. Aside from SETI, which is directional, we've all but quit broadcasting interpretable analog waves just a decade ago, thanks to the switch to digital formats. That means, out of maybe, 5 billion years, you've got maybe a 100 year window where another, similarly equipped civilization could "hear" us, and assuming parallel development, and that said civilization is similarly stupid enough to broadcast its location (as we are)... Given the time involved, the odds of any two such civilizations being in existence, broadcasting and listening for such signals, at the same time, are next to none.

Even if every star had a radio broadcasting civilization orbiting it at some point in its history, the odds of any one of them being in a position to hear another are pretty damned astronomical.

We don't even see planets light years away, we see the shadows they cast as they pass by their star.

The light we see from those stars is from a past long gone.

Our radio signals have only traveled a tiny distance compared to our galaxy, being distorted beyond recognition along the way.

Statistically there is life out there, but it's such a vast scale we have yet absolutely no methods of detecting it. The most we can do is take educated guesses about how other stellar bodies look based on the incomplete knowledge we possess.