When you look up remember that the majority of what you see is in the same sub-arm of the spiral arm of the milky way that we are in. Of those we can see a large number or binary systems - two stars orbiting each other. We fancy telescopes we can see a lot more of course.

All the power of stars, and most of them still are not powerful enough that we can see them even on a dark night! What chance does any alien have of sending a message that reaches us if the light from their star isn't even powerful enough to be easy to detect? It was suggested elsewhere that even if we find an alien, we probably cannot respond if they are more than 100 light years away just because we can't get a message out powerful enough that they can detect (I can't verify this claim but it is reasonable)

It's probably worth considering that across a sufficiently large distance, they effectively no longer exist. Their signals haven't reached you, and with the increasing speed of the universe's expansion, they will never reach you. Eventually, everything will be expanding at well beyond the speed of light, so short of being able to cut through space and time, we're not reaching any of these destinations. For all intents and purposes, they don't exist for us. We'll never see any evidence, nor could we ever see any evidence.

So in reality, there is a maximum distance we need to consider - the distance where any signal would have any chance of reaching a detectable region.

But besides, this still misses the most important part. Until 10 billion years ago, stars were much too big and poor in metals and unstable. We didn't have an earth until 5 billion years ago. It was inhospitable to life for a LONG time. We've only had multicellular organisms of any kind for 800M years. Our star is unusually calm, meaning we don't have to worry about being bleached every 5 million years or whatever.

I've said this a couple times in this conversation, but the best guess is honestly that we're the forerunners.

I have no doubt that civilizations are out there. Maybe a handful, maybe nearing infinity. But out there.

The problem is "out there" is so far away, we are all isolated on our own island worlds. An ocean of space so vast we cannot meaningfully traverse it with probes or radio, to say nothing of manned interstellar flight.

But it never gets boring for me to imagine what other civilizations there might be, and how they might be different from us and from each other.

> We have billions and billions of data points showing the Universe is empty.

Wat?

"Absence of Evidence is not Evidence of Absence", Carl Sagan

You're right, but it doesn't matter - we're finding evidence of absence everywhere we look.

(Again, please note that I'm only speaking to technological civilizations; I fully believe the universe is teeming with microbial life.)

This is just an absurd assertion.

> we're finding evidence of absence everywhere we look.

Show your work. Show me any such "evidence".

You seem to be unfamiliar even with what kind of data cosmologists and astronomers process.

Sure thing.

We've been to the moon. There are no machines. We've been to Mars (via machines). There are no civilizations. We've seen the orbits of thousands of planets which are absolutely too hot for any biological processes to synthesize. We've scanned countless stars and determined them to be too unstable for anything to survive in their orbit. We've looked into every single confusing thing in the universe we could find and have seen natural explanations for nearly every single phenomenon.

Do you think we just don't know anything about the universe? There is tons of evidence of absence. It might not be complete enough to make a guess yet, and that's a fine argument to make, but it's weird to pretend that the evidence doesn't exist.

edit: And again, while it's not evidence of absence, I'm still waiting for a galactic signpost to pop up somewhere. Unless you've got some explanation for why not one single civilization anywhere, even ones which have left their home planet and have nothing too serious to worry about with respect to retaliation?

Your infantile understanding of science is a terrible citation of 'evidence'.

By your logic:

"I looked in every volcano on Earth, and was unable to find life. This is evidence that Earth is a lifeless husk."

Also by your own logic:

"We've looked at handful of... planetary orbits(?!)... and have yet to find a single 'signpost' of civilization. This is evidence of absence."

Learn how to gracefully admit when you are wrong, and stop doubling down on ignorance.

Your infantile reading comprehension is a terrible counter to my comment.

>"I looked in every volcano on Earth, and was unable to find life. This is evidence that Earth is a lifeless husk."

How did you pull that out? This is a terrible analogy.

>"We've looked at handful of... planetary orbits(?!)... and have yet to find a single 'signpost' of civilization. This is evidence of absence."

Also not remotely what I said. I'll assume this is just a troll account and move on.

Yes. The Fermi Argument strongly implies this sort of question is pointless, an exercise in wishful speculation.

Probably thousands of years from now, but I do wonder when people will stop using "the universe is too vast to know anything" as an excuse. We've still got people pretending the ocean is an enormous, occluded mystery.

The idea that humanity is the only civilization in the entire universe strikes me as the absolute height of human arrogance.

Lots of things seem arrogant to lots of people, but without some logical basis, it's worth ignoring.

This is an ad hominem argument. It attacks a position not because it's wrong, but because if you advance it you're a bad person.

Not really. An ad hominem argument would be more like calling GP an idiot for thinking it should be "trivial" to find civilizations in the universe, but I wouldn't do that.

Yes really. It attacks a position for being arrogant, even if it's correct. What else could this be except an attempt to bully people who might claim this into silence?

You may not have realized, or allowed yourself to realize, that you were doing that.

>There should be some signs somewhere that could be recognized universally as either "stay away" or "come here".

There might be ones who don't bother to try to communicate at all and instead prefer focus on themselves for whatever reasons