They would want to wipe out competition, like Lions killing Cheetah cubs.
My “favorite” explanations (not that I necessarily believe it) involve predators.
The question started with “Is there intelligent life out there?”
Then it became “Why are they hiding?”
With the obvious follow up … “Why aren’t we?”
They’d want to wipe out any competition. They’d want a nice, warm, water-filled planet to use if needs be. They’d want unlimited, unfettered access to all of those - plus exotic dumb animals that couldn’t fight back and would look good in their zoos (before they all become extinct).
If they have enough ambition to overcome interstellar travel, they’re going to want everything we have. They won’t want/need to share our stuff (and we can’t spare much anyway, with 7 billion people and billions of animals), they won’t need to go to the bother of sharing their technology and they certainly won’t want our diseases, viruses or ideas infecting them. If they’re so advanced they can get here, what would they need us for? They won’t leave us to potentially destroy our planet when there are no easily accessible resources nearby (as far as we know for certain).
My husband’s uncle was an engineer for NASA back in the 70s. He stated that the US government was hiding evidence of alien life. He was very matter-of-fact about it. I’m not sure I believe that, but I don’t think it’s entirely unlikely, either. So, I’m undecided. I feel it’s very likely that there is a lot of other intelligent life in the universe, but the distances are great, and it’s rather a pain to transverse them. I imagine lots just haven’t gotten around to it yet, so how would we know about them? And maybe some have, but it’s a need to know thing. I like to think that we’re not all that rare, either way.
If they’ve got the technologies to achieve interstellar travel, they don’t need anything we have, including our planet.
the universe is so big and interstellar FTL travel is so difficult/impossible that life forms have a hella low chance of ever discovering each other
I favor the Prime Directive hypothesis: They’re out there, they probably know we exist, but they have a hands-off policy until we achieve some benchmark of development. This is slightly different from the zoo hypothesis, in that they might not be interested enough in us to keep constant watch.
I agree. Humanity just got lucky. Most of the universe runs the way Fermi predicted. Intelligent alien races exist and they expand out to all of the planets they can - in the process, wiping out any potential intelligent races that might have evolved on those planets.
But Earth happens to be located in the midst of the Galactic Federation of Wise and Benevolent Aliens Who Have a Long-Lasting and Stable System of Government and Are Powerful Enough to Make It Stick. And they saw that Earth had the potential for intelligent life millions of years ago and declared it off-limits to colonization.
This.
I think we’re first. There are lots of possible plateaus in evolution - going from one-celled life to multi-cellular is a big mystery, but I think life does develop a lot and is pretty resilient.
But I think the heavier elements needed for life didn’t get created with the first stars - it took a couple of generations before stars started creating carbon, iron, etc.
One possibility I think the OP misses (maybe it fits into the ‘zoo’ hypothesis) is the Star Trek hypothesis (*edit, or as **Chronos **has it, the Prime Directive) - they’re out there but not making contact until we become advanced enough to start leaving the planet. But I don’t think that’s the resolution.
One other hypothesis missing is the ‘fix up your own home’ hypothesis. Interstellar travel is possible for civilizations more advanced than us, but it sucks. It’s preferable to ‘collect’ cosmic dust or brown dwarfs or whatever, and make your own star when your current star is on its last legs. Create it less than a light year away and you don’t have to move far.
But I think we’re first. I guess I’m an optimist and think we will conquer interstellar travel.
Bad modeling. Instead, we’re a planetary civilization with immense resources, and billions of dollars to spend on astronomical exploration.
A small band of survivors wouldn’t have built a space station or sent probes to Jupiter.
My guess at present is that there’s a great filter that’s behind us. OUr best guess is that intelligent life requires a planet in the habitable zone of a stable star to sustain life for billions of years. I suspect that’s rare. The next generation of planet hunting probes should give us some data to know for sure on this point so I may revise that answer in a few years.
But keeping with that hypothesis, if intelligent life is rare then there may only be one planet every 5 or 10,000 light years apart. That would be very difficult to detect even if we exist near to the same time which is also unlikely. Assuming that the speed of light is unbreakable then that means that biological travel to other planets is nigh on impossible so I doubt there are predator species out there.
I do think we’re close to something akin to The Singularity. While I don’t think it will give us God like powers I think it will profoundly change our technologies and how we explore space and the universe. I think it’s possible we’ll know about a handful of planets that have real chances of harboring advanced, and maybe even intelligent life in our galaxy in the next 100 years.
This all sounds a lot like “Why do you never see baby pigeons?”
Why should we expect to have seen evidence of other intelligence in the universe? We can barely get a good look at our own solar system.
Because of the Fermi paradox. If there’s life much more advanced than us, they should have already zipped around the galaxy and visited our planet. Life evolving to our stage takes a long-ass time. However, once civilization gets going, technology advances very rapidly. Fermi suggested that either nobody else had advanced to our state, because the odds that some other species was about where we are, but hadn’t yet colonized the galaxy, was a small window (maybe 20 million years - that’s a drop in the bucket compared to the 4.5 billion years it took to develop life and then that life developed civilization), OR there’s some other weird reason they didn’t colonize earth before we even got a foothold.
I think we’re fucked.
Intelligence is an awesome thing, but it’s also very much a destabilizing force.
We’ve made huge changes to our environment over the past few hundred years alone without even really intending to. We were pretty lucky to make it through the Cold War without wiping ourselves out, and that was with arguably rational behavior on both sides. The march of technology means that individuals will over time come to wield greater and greater power, and there are decidedly irrational people out there.
I hope I’m wrong.
I understand that concept, so I guess my problem is the assumption that more advanced civilizations would have zipped around the galaxy and visited our planet. By the same assumption I should have been looking for baby pigeons. It’s only paradoxical if you make that assumption. While there is justification to think that such civilizations could exist, there is no justification to think they would have found us, or even gone looking.
Then you probably want this poll option:
The concept of physical colonization is hilariously backward for advanced species
I opt for the Great Filter being behind us, and I opt for the Great Filter being known: it’s the transition from unicellular to multicellular life forms. We know that life evolved almost as soon as it was possible for life to exist on Earth, arguing that it’s a relatively easy, common phenomenon. We also know that having evolved, it remained at the unicellular level for two billion years, which indicates that the transition from unicellular to multicellular is a LOT more difficult and complex than life itself arising.
Once multicellular life forms arose, there was an explosion of variety in species, as multicellular life forms have a huge evolutionary advantage, another indicator that the transition from unicellular to multicellular is rare indeed.
The history of multicellular life on Earth is just over half a billion years old. In another half a billion years our sun is due to expand and make Earth uninhabitable. In short, if the transition on Earth had taken three billion years instead of two billion, when the sun expands it would just burn off a big algal mat that covered the oceans.
I would argue that this is the almost universal fate of life in the universe: become an algal mat that gets wiped out when living conditions become unfeasible.
I voted that the Great Filter is ahead of us, and we’re probably screwed. Most civilizations suffer some sort of apocalyptic disaster before interstellar space travel becomes a realistic possability, and if anyone survives they’re pretty much reduced to a subsistence lifestyle. The reason is, once civilizations develop the means to destroy themselves, sooner or later it will probably happen, because the level of foresight & cooperation needed to keep the genie in the bottle forever is just too high a hurdle to mount.
I’ve long thought that the passages in Revelations that talk about fire falling from the sky might be an attempt to describe a vision of nuclear war, ie WWIII. On other planets, there might be any number of analagous disasters involving biological weapons, nanobots, weather control schemes that go out of control, or just resources being depleted to the point that civilization cannot continue at its current level.
He was pulling your leg Renee. SPOILER NOTE: Because he was an engineer for NASA, he used that for a good yuk. Its not uncommon.