It should be obvious that we can not possibly be alone in the universe. Mankind is not ready to acknowledge that we aren’t the only thing out here yet.

I would like to see the reaction of religious conservatives to the fact that there is intelligent life elsewhere in the universe. I would love to watch their mental gymnastics to the knowledge that other beings won’t know about Jesus and would likely not need to know.

To know that they are out there would have to be enough to satisfy those who might care to know.

Assuming by “mega civilisation” you mean one that has colonised thousands of star systems:
They may be out of range of your current spaceships, but that does not mean you are out of range of theirs. In fact, the size of their empire probably means you are very much within reach of their tendrils. Them having such a vast domain also tells you that they are aggressively expansionist, so sooner or later they will be at your doorstep. Would you like to be unprepared and surprised?
It furthermore tells you that interstellar travel and colonisation is both feasible and practical. Their expansion also tells you that it is necessary, lest you end up with nothing, while they grab any system they can. So get cracking.
You can also now focus your observations on them. You may be able to observe their mode of interstellar travel. If you see many movie spacetime distortions for example, you can infer that they are using some kind of warp drive. So you now know that warp drive is not just theoretical, but actual. You can now focus research on that, and expand your understanding of science and technology.
You also have seen one massive civilisation. How many smaller ones have you not found yet, that you are fairly certain now that they have to exist? How close are they? Are they a threat? If you find them, can you contact them? Trade with them? Share scientific and technological knowledge?
There are so many consequences following from such a discovery.

Waste of time? Seriously? The most important discovery of the human race is a waste of time?

Science is not about what is practically useful. It’s about discovery and furthering knowledge. Does it matter that the Higgs Boson was finally discovered? You can’t use it for anything.
Does it matter that the center of our galaxy has a black hole? You can’t use it for anything
Does it matter that DNA evidence shows that there was an influx of immigration to Scandanavia in Viking times? You can’t use it for anything.

You may argue that it doesn’t matter, that it’s a waste of time. If you’re serious about that, then I pity you because all of that stuff is really fucking cool.

When I say it’s a waste of time, I mean, can we not assume all these possibilities are likely, and instead of wasting a major part of our resources on discovering them – we can use those resources to improve technologies that help us survive imminent dangers.

Or, say our ship is sinking, and one jackass is using the fancy brass telescope to spot land far off. Would you not kindly redirect that effort to the immediate problem? The telescope is not the dire task.

I think the idea of looking back in time for the early universe is a great effort. It answers questions like what is the nature of space time, and the expansion of the universe. These are questions that could leap us forward. But, building a telescope specifically to find the aliens? Seems like we can assume that we are not alone, and jump ahead to the efforts we’d begin had we spotted the aliens. I am not of the opinion that simply observing a warp drive signature will a) require a ‘traditional’ imaging telescope placed at a lagrange point. And b) resolve how it’s done.

Some of our greatest minds are working on such matters, aliens be damned…. Why not ask them if the funding for the alien telescope could be better used to flesh out the research on theoretical interstellar propulsion systems.

I think, like Elon Musk, that we need to be a multi-planet species. I think that should be a priority. And, when you’re setting priorities you sometimes shelve cool side quests to achieve a primary objective.

I asked not because I have an opinion, I asked because maybe I could be enlightened on why observing alien life is such a pressing goal.

I think quantum entanglement will find them, no telescope needed to spot their planet just yet. Unless we’re trying to go there on an Ark. Is that it? Where do we send the Ark?

To say it’s a waste of time depends on who you’re talking to and what their interest is exactly.

“When I say it’s a waste of time, I mean, can we not assume all these possibilities are likely, and instead of wasting a major part of our resources on discovering them – we can use those resources to improve technologies that help us survive imminent dangers.”
– Humans are to NO degree, devoting anything anywhere like “a major part of our resources on discovering them”!

“Or, say our ship is sinking, and one jackass is using the fancy brass telescope to spot land far off. Would you not kindly redirect that effort to the immediate problem? The telescope is not the dire task.”
– This analogy, too, isn’t compelling, unless there’s something else the jackass could be doing that’s particularly necessary for them to do. For any ship worthy of the name “ship”, it is definitely worthwhile to have at least someone somehow establishing where the nearest safe place to land a lifeboat is, if that’s not currently known. Otherwise, everyone aboard might short-sightedly focus on getting into lifeboats as soon as possible, only to find that no one knows which direction to row, potentially leading to many, or everyone, being lost at sea.

When you’re talking about an entire planet, it’s nonsense to say no some should be doing task X, unless task X is clearly an actively BAD idea.

” But, building a telescope specifically to find the aliens? Seems like we can assume that we are not alone, and jump ahead to the efforts we’d begin had we spotted the aliens. I am not of the opinion that simply observing a warp drive signature will a) require a ‘traditional’ imaging telescope placed at a lagrange point. And b) resolve how it’s done.”
– Observing evidence of vastly superior alien technology, could very likely point us to what’s possible, and possibly clues to how it’s done. That could help people think about what to research, that otherwise might tend to seem like idle science fiction ideas.
– What is your reasoning that leads you to a) and b)?

“Some of our greatest minds are working on such matters, aliens be damned…. Why not ask them if the funding for the alien telescope could be better used to flesh out the research on theoretical interstellar propulsion systems.”
– Fortunately for happiness of Earth, people are given some measure of choice in determining what to do with their lives. There’s already a catastrophic amount of bias toward resources going toward things that will make mega-wealthy corporations and their mega-wealthy owners, even more wealthy. And there are already plenty of people suggesting focusing on other types of projects, and plenty of people doing those other projects.
– The way you’ve worded things here, it sounds like you think zero people should be spending any time on searching for extraterrestrial intelligence. But perhaps you just mean that some of the projects you’ve mentioned seem extravagant and like not the best use of resources. In that case, I might agree with you, but I’d need to know a lot of details that may not even fully be public knowledge.

“I think, like Elon Musk, that we need to be a multi-planet species. I think that should be a priority. And, when you’re setting priorities you sometimes shelve cool side quests to achieve a primary objective.”
– I think we should focus on keeping this, the best planet for life as we know it, from becoming unlivable due to our own actions, first. Looks to me like we may be going to blow that, so if you’re talking about choosing priorities, I don’t think we should be trying to colonize anyplace else, before this planet isn’t in such peril.

“Unless we’re trying to go there on an Ark. Is that it? Where do we send the Ark?”
– No, that’s not it.
– More like, we see some stuff that leads to major breakthroughs in physics and technology. And, other things like people really wanting to know what’s going on with other intelligent life out there.

Note too that if, as you suggested, we spot a major civilization on the other side of our galaxy, that means we’re seeing what they were up to about 60,000 to 70,000 years in the past, which means they’ve had that much time to improve their technology beyond the point where they were so advanced that we could detect them then.

Discovering whether we’re alone or not would be a watershed moment for the human race. The scientific curiosity is a big deal of course, but imagine how the information would change the context of human relations.

IMHO, the decision on whether to try and contact them would depend on alot of things. If indeed you’re seeing a large EMPIRE, that would kind of be scary. But if it’s a civilization that is just very old and has colonized a bunch of uninhabited planets…that’s not. What we know, how we know it would have a huge impact on the decision.

Realize that our radio signals are now hurtling through space announcing our presence…and I’ve heard that the first large one is actually of Hitler, so…. great first impression.

There are more than 7 billion people on the planet. There’s plenty of money. We don’t all have to concentrate on climate change. A few of us can look at the stars. We can use a small portion of our money looking at the stars.

We would not be contacting them any time soon. We are talking about distances of tens of thousands light years. The likelihood that they could do us any harm is pretty minimal. I definitely think that we should try to contact them.

“Beyond the range of our spaceships” might not be beyond the range of their spaceships. Even if it is, it would be a MAJOR opportunity to learn about civilization(s) on another planet. What have they learned about living as a society? What have they learned about science? Maybe we know something they don’t, and vice versa.

What good is it? It’s the fucking most amazing shit ever. The implications are endless.

Because of the distance involved, they very well could have snuffed themselves out while the light of them being was brought to our eyes. And any signal we might send to them would be so deteriorated by the time it got there that anyone who might still be there would not recognize it for what it was. And we will snuff ourselves out before they got the message as well.
So, what good is it?