Megastructures, the exhausts from fusion drives, etc. No question about it.
But vey far away, no question of it physically coming here.
Would that in itself have significant effect on human society, and if so, what would it be?
And there would be denialists and conspiracy theorists, people who would blame it on some group as an effort to change their deeply held beliefs and views.
Religions would face a huge obstacle in bridging their creation myths, more people would become atheist and non-religious.
Knowing something is possible is a hugely motivating factor. The department of defense and every international analog would want bigger and bolder weapons, money would pour into science. We'd fund astronomy and space exploration orders of magnitude more. There would be a renewed push for humans on Mars and beyond.
We'd want to know if alien life was biological or an AGI. We'd push harder on our own advances, but also become more aware of how this acceleration affects us.
We'd keep looking for life in our backyard. We'd be worried about it. Popular science and science fiction would communicate that risk and would lead to new cultural overtones. Zombies and superhero movies get replaced with alien invasion films.
I think we'd accelerate everything.
Edit: my post is proving controversial because of my statement on religion, which totally flies over my main point. With regard to religion: (1) I haven't made any value judgments, (2) the impact of science, technology, and modern culture has deceased religiously in the West measurably. I should think incontrovertible proof of alien life would only contribute to this trend.
Religions have faced and easily overcome that obstacle countless times.
Example, in modern concise English: https://open.library.okstate.edu/introphilosophy/chapter/aqu...
Original excerpt: https://homepages.uc.edu/~martinj/The%20Infinite/Aquinas%20-...
As an atheist and a scientist, Aquinas' works are still amazing to me.
There's plenty of evidence that religions can survive doctrinal challenges; Catholics largely decided evolution was God's mechanism for creation, while some Protestants decided it was a Satanic trick.
Look at things like Sabbath elevators and the 18 miles of fishing line that rings Manhattan (https://www.npr.org/2019/05/13/721551785/a-fishing-line-enci...). Religion is ever-flexible; humans are clever when motivated to come up with a solution.
Counter point. Religions with a very rigid view of highly sentient life being unique to earth and humans would have a hard time. Others would say that the universe produces sentience wherever it can and it is fundamental to the universe. You see this sort of idea, of sentience permeating the cosmos, in pantheistic and / or less antropocentric religions. It would be seen by some as a validation.
Religious worldviews are very diverse.
The stronger the dogma, the more heretical change is. And there are a lot of very dogmatic Islamic branches.
If religiosity was based on rational weighing of evidence, it would already be gone. But that's the wrong model. There is not enough room to describe the right model in this margin :)
Also, new religions arise all the time, which can incorporate the latest data.
That's why I tend to agree with echelon.
There's a big difference in the ability to ignore genetic statistics and measurements strongly proving evolution... and "Aliens exist."
The latter would more deeply penetrate the average person's understanding, and hence couldn't be ignored and would have to be incorporated into religious worldviews. It'd look a lot like the geocentric to heliocentric conversion, except bigger.
And like heliocentricity, an extraterrestrial civilization existing would only accumulate further alternate evidence over time, which would crowd dogmatic denialists into tighter and tighter corners.
We think that's how our brains work, but in reality unconscious processes decide what would be an advantageous belief to have, and another part (sometimes called "the press secretary") comes up with a rationalization that we believe is really why.
One can not simply opt to not believe what everyone around them accepts.
Some part of you realizes that it's better to fit in with the society you're part of than to take a stand for the truth of atheism. And so you become a believer.
Given recent experience with other incontrovertible things like climate change and COVID, and the public's plummeting trust of science, technology, experts, and institutions, I'd guess the denialists would be more than a handful, probably more than 50%. Right off the bat, most devout Christians will deny it as a hoax since it calls into question more of their holy book's version of history. If the announcement is made by anyone associated with the government, like NASA, an additional 40% or so of the population will deny it because it was announced by the government of "the other" political party. Beyond that, you have the growing band of professional contrarians who will deny it simply because an expert discovered it--the more incontrovertible the evidence is, the stronger they will deny it and be convinced they're right. There will be many calls to "do your own research [on YouTube]".
I fear the world would just keep on chugging along, with the majority in denial, ridiculing "those silly ivory tower elites thinking they know everything with their telescopes and education".
I don't think that's why professional contrarians deny things: they do so because it makes them $$$.
We think our galaxy has 100 billion planets.
"Incredibly rare" isn't rare with those numbers, and "unique" is vanishingly unlikely. The chances of there being a planetary formation scenario that happens only once in 2^23 iterations is... low.
> How would life evolve without a magnetosphere?
Our magnetosphere isn't even unique in this solar system; Jupiter has an immensely strong one. We've likely detected at least one on an extrasolar planet (http://data.iap.fr/doi/bjaffel/20210727/). Plus, Earth-style life needs a magnetosphere; that doesn't mean all life does.
That pool reduces quickly eliminating all planets without surface temperatures permitting liquid water, and of the right mass to permit something to grow. Among those, how many have a magnetosphere for billions of years, water, and the right amount of selenium to permit cell growth but not enough to poison everything? Consider also that the Sun may not even be from this galaxy. Maybe its galactic migration, the Milky Way cannibalizing its host possibly dwarf galaxy, had something to do with it. It makes our circumstances even rarer.
I'm just playing Devil's Advocate here. Of course there's other life in the Universe, likely intelligent life. Infinite diversity in infinite combinations.
There's debate over whether viruses qualify, and trillions of planets to check for microscopic stuff.
I see this as the most likely alien discovery scenario, because so far we haven't seen any, so they are probably pretty far away.
Heh, predictions of precisely such a scheme have been popular among conspiracy theorists for years. "Project Blue Beam" and the like. It's also the premise of the Watchmen comic book.
The worst part about how awful the Warhammer 40k universe is IMO is how very human the Imperium is. They hate the xenos. They hate the heretics. They hate themselves, each other, and everything else.
Hate! Hate! Hate! An emotion as pure as it is deep! Hate! Hate! Hate! Let it flow, let it run free!
—Inspirational Verse, Imperial Hymnal Vol. IV
Humans rarely stop hating one another because of a foreign threat, instead we just add more hate to the pile. Quite depressing.
If you can see them far away it doesn't mean they are not also close by and you can't see them.
You should update "there are aliens close by" to a much higher probability
That we know of. Who knows if Alcubierre drives work.
The speed of light being a speed limit is a consequence of the geometry of spacetime. I'm convinced FTL is as impossible as it is to have an angle greater than 180 degree between two lines in Euclidean geometry.
I have to say I'm uncomfortable with the idea that we've discovered everything there is to know about the physical rules of the universe.
Sure, any reasonable scientist would tell you that there is a non-zero chance that we're wrong about these things and both perpetual motion and FTL are actually possible, it's just that we have an extremely high confidence they're not.