A search for technosignatures around nearby stars
arxiv.org
arxiv.org
In other words, the likelihood that they either lived before or (will live) after us is overwhelming, since the time scale of the universe is so vast compared to the time scale (with our one known example) of a civilization.
Our timeline is like the blink of an eye, compared to the age of the universe. Very unlikely that nearby blinks would happen at exactly the same time, even with a 11,000+ multiplier.
200 years ago no one knew radio communications were possible. We still don’t understand quantum entanglement. Our understanding of physics, while more advanced than the past, is still clearly limited. We may find that there are better ways than radio to transmit data, and this could explain why our radio surveys have so far not detected extraterrestrial data packets (as far as we can tell).
What's more telling for those in the neighborhood is the strange amounts of O2 in our atmosphere's spectral lines. That came to be long before us, it will persist long beyond us and it's a clear indicator of a non-geological process that might intrigue aliens.
One other thing I came up with on a long evening walk recently was to check for gravity fields. If you have all bigger pieces of matter mapped well within galaxy, and you grok all physical laws there are, you should be able to predict movements and gravity fields for billions of years with high precision. Kind of make a complex checksum of given galaxy. If this changes for no predicted reason, bingo you just have a very strong candidate of life evolving enough to escape its planet and start moving big chunks of matter around (think big asteroids or changing orbit of planet slightly to ie counter some natural catastrophe like greenhouse effect / ice age, or living near slowly dying star).
Obviously this is way ahead of us and maybe even not possible, just a fun thought. But if you start space mining company by any chance in the future, please don't move matter around too much.
Basically we live in the goldilocks zone of our galaxy.
Stars further towards the center are being constantly bombarded by types of radiation that make the formation of structured self-replicators almost impossible.Entropy rules.
Stars further towards the rim have not yet gone through enough generations to produce the abundant heavier elements needed.
We live in the zone that is both old enough and stable enough for technologically adept life to thrive, and we turned up on the scene about as early as we could.
So we are probably just one of the first.
We don't really have any way to know that. Considering that there may be as many stars in the sky as grains of sand on Earth, there are many many unknowns.
For another example we don't know for sure if our universe is the only one and it's entirely possible that everything that could ever happen plays out in real time across and infinite number of universes. We don't have any way to physically measure that possibility yet. We only have mathematical theories.
Similar to how Copernicus proposed the heliocentric model, maybe our universe is not even the center of existence?
It is humbling to imagine.
The fact that we don’t see the light of stars, or whole galaxies replaced by dim infrared waste heat emissions means either (1) new physics will point to free energy solutions that circumvent thermodynamic laws [unlikely], or (2) we are the first.
Which seems to be the most likely explanation to me.
1. disassembling the stars to make them live a thousand times longer
2. it only takes one expansionist civilisation seeking interstellar exponential growth — even if 99.9% of civilisations are quiet, that's just 3 digits of the 22-digit number of stars in the observable universe.
Why would they do that when there are insane amounts of start with billions of years of life ahead of them. What purpose would that serve at this point in time?
In that case, the stars are not 'waste'.
Historically, this idea of growth as method for advance is only a few centuries old. It's not hard to see its end as efficiency keeps increasing.
Going K3 to 100 billion stars of the galaxy "only" gives you a 10^11 constant factor speedup at enormous expense and with Amdahl's penalty at galactic scales.
We are indeed among the first simply because of the sheer amount of time left ahead of us vs. behind us. It's basic math. We are at 0.014% of the expected duration of this universe.
Life as we see here on Earth is extremely adaptable. Give it harsh environment, and unless its too much immediately it will adapt and actually take advantage out of it (ie too much radiation? well we can mutate to our ideal desired form even quicker).
Also, 1 billion years doesn't mean much in this cosmic scale. But imagine if civilization like ours had that much headstart. Well, you can't imagine, and neither can I in same way homo erectus couldn't imagine CERN particle accelerator or black holes.
Homo Erectus takes us back around 100 million years. A billion years gets us to very simple multicellular life which can't do imagination at all. Or logic. Or thinking. Or creativity. Or much of anything else.
So... a billion year old civ is going to have very fundamental abilities which are completely beyond our comprehension.
It's like Dunning Kruger on a cosmic scale. Except that with Dunning Kruger there's usually some potential to learn a way out of ignorance.
Here there isn't. Not only can we not do it, or understand why we need to do it, we can't see - never mind reach - the first rung of it.
Maybe not. There's no evidence that species can continually adapt and evolve to higher levels of intelligence. Humans are already hitting limits for how much we can think, figure out, etc.
But by that same token, maybe so. Humans aren't exactly the cream of the crop when it comes to higher critical thinking and emotional intelligence.
Is there any biological research that takes a look at a single or sequence of species maintaining civilizations lasting x amount of years?
We will have the technology to alter the DNA to increase our intelligence significantly. There are limits, but I don't think it is likely that human beings are at the peak of what is biological possible.
- When we reach the biological limit, we may extend ourselves by merging with technology. Our brains might be connected to a computing device that amplifies our capabilities. It may be so seamless that when answering a question, you won't notice if the knowledge was stored in your physical brain or retrieved from a central archive.
In the near term, I just wish they'd figure out how to make better mechanical parts for humans. Our natural joints suck, particularly knees and ankles. It really shouldn't be that hard to make mechanical replacements for various parts of the human body.
There is zero evidence of this.
What would that mean?
Once our intelligence encompassed communication then it began growing culturally. I.e. we are able to treat math and engineering as no biggies, despite humans needing millennia to realize "nothing" could be a number called "zero".
It's fair to say the 21st century shows no signs of intelligence slowing down. We keep finding ways to think more simply but more effectively.
Huh? Where did you get that crazy number? 100M years ago was the age of the dinosaurs. Homo erectus was around somewhere between 250K and 1.6M years ago.
> So we are probably just one of the first.
Those two sentences don't really mix. We have evidence that points to life forming basically immediately once the conditions are right. That means that for us to be the first, nowhere else in the galaxy and universe could have had the conditions. That just seems incredibly unlikely. Even in our own Solar System, other bodies like Mars had the conditions for life before Earth did.
In fact, given that most of the easily accessible coal and oil deposits will have been used up it might even be much more difficult for a subsequent species to get as far as humanity has. (Although that might be balanced a bit by lots of the metal ore being pre-mined and near the surface)
There'll be plenty of time for nature to compact and bury much of the biomass from the previous sentience attempts.
What's the evidence for this? Not asking rhetorically, I'm curious and want to read more.
Basically, as my understanding goes, life is effectively as old as the Earth is. As soon as it cooled down after forming and had liquid oceans, life started, which happened just a few hundred million years after Earth formed.
There is the book Every Life is on Fire as well, describing how life began to dissipate heat in the environment of molecules in water being heated. That seems to imply life will quickly start in such conditions. (Note: I don't strongly recommend the book, as it has a lot of religious stuff in it and honestly isn't that well written, and I have mainly learned about the author's theory elsewhere.)
Not sure this logic makes a whole lot of sense.
Imagine a universe similar to ours, but with a lifetime cut short by a doomsday device. Would you expect any difference in the likelihood that mirror humanity coincides with another alien civilisation?
Independent of other factors, adding more time doesn't really reduce the number of civilisations existing at any one time, it gives more time for civilisations to emerge.
Your logic suggests there is a fixed number of civilisations to distribute evenly across the lifetime of the universe. Now, the number of civilisations may be limited by usable energy for life to consume rather than time - but in that case I'd expect civilisations to cluster at the beginning of time when entropy is low.
Edit: in fact Drake didn't actually include any term for age of the universe in his equation.
But I think I was imprecise with my language. By "age" I meant the total lifetime of the universe as a place with planets capable of supporting life, rather than the amount of time between the big bang and now.
I don’t believe the current absence of evidence is much of a useful data point. Until we have scoured other star systems and the rest of the galaxy turning over rocks we can’t really generate useful empirical data to fill in the numbers on the Drake equation. The paradox of “where is everybody” has myriad solutions.
A mistake definitely lies in philosophers and theorists believing their sci-fi ideas are better than anyone else’s. Certainly not useful data towards writing papers that form a proof of any number as a solution. It’s hard to prove an absence, particularly when there’s a universe of empirical data that can be potentially gathered but hasn’t been yet.
If I was a betting person, I’d put a stake on there being life somewhere like Enceladus. Even life from earth in the form of fungal spores has existed for long enough to escape and float around the galaxy - they’ve had a few hundred million years. Life here could have also landed from elsewhere as easily as terrestrial abiogenesis. There’s just so much we don’t know and haven’t tested. Not being able to pull radio signals out of the noise proves nothing given the mere seventy years of attempts.
I’m not sure about many worlds, and how that could be proved either to be a useful part of science. By the same token, in an infinite universe, then literally every single possibility and permutation is being tried, so in that case, yeah there’s life everywhere. Including a universe where I’m out being the first human to find it rather than writing this comment.
universe begins
0.1 Gy
first stars
9 Gy
our solar system begins
0.5 Gy or less
early life
3.5 Gy
complex, multicellular, macroscopic life
0.5 Gy
sentient, intelligent life
9 Gy: After first stars, how many generations do you need of large stars, synthesizing heavy elements, going supernova and shooting the heavy elements around, contributing to the condensation of new stars (now with some heavy elements to begin with), until you cal form solar systems and planets like ours, with enough iron and heavier elements to make life chemically possible. Do you need to wait this full 9 billion years, before planets with the chemical composition of Earth appear, or did they already appear sooner?
3.5 Gy: How long does it "usually" take from early microbial life, for evolution to develop complex multicellular life? In our case it took 3.5 billion years, but are we among the fastest, or the slowest?
Its a difficult argument, as all of life manipulates its abiotic surroundings one way or another. Yet the antropocene is clearly at least one qualitative step up. We only have this one data point (our own) so make of that whatever you will. But it doesn't take an ultra-pessimist or doomist psychology to see that on the basis of our behavior the odds that technologically enhanced life self-destructs in short timescales are, indeed, non-zero.
If "intelligent" biology is an intrinsically unstable system (can't self-regulate because primal drives for reproduction, dominance etc highjack mechanisms that are too powerful for its own good) this would make the absence of technosignals self-evident.
We already have climate change, advanced AI (that may eventually be able to produce more technology by itself), and a planet of organisms that are counter to growth. Deforestation happens because the long-term costs are not shouldered by the present generation.
In some way, I believe the end of times is near, but that humanity has TWO possibilities:
(A) The planet is destroyed via advanced technology and most humans die, only to repeat the same mistakes again, OR
(B) We reach a critical mass of enlightenment that consists of (1) a cautious approach to growth, (2) a moderation in the use of technology, and (3) a stable, healthy relationship with the biosphere.
The eventuality (B) is certainly possible if one by one, we start to adopt a philosophy that economic and technological growth isn't the right path and we slowly give up all this advanced stuff for a slower-paced life centered on local communities, local economies, and less efficiency in return for a more peaceful life.
1. We do not have advanced AI. We have LLMs. They're not intelligent, not creative, and are never going to be. I'm with you on the other things, though.
2. The planet will not be destroyed by anything we do. H. sap. might go extinct along with many, many other species, but give the biospehere a couple of million years and it will all bounce back, sans humans.
I've been living/trialing the path you suggest in your last paragraph for 30 years. Sadly it's not gone viral. AMA. ;)
Yes, it is true that the planet won't be destroyed, that is a good point. Only we might, like you said. Though, if many other species go extinct, it is sort of like destruction in a way, even though it isn't total.
Feel free to reach out through the contact info in my profile if you want to collaborate.
The first time it happened, as I understand, there simply wasn't a huge amount of oxygen in the air, so things didn't burn and having megatons of carbon rich organic material lying around wasn't likely to catch fire and jump back into the air.
Now, if I leave a bunch of organic material lying around it'll catch fire and go right back into the air.
I'm not sure how long that'll take to change, or what impact that has on future life here on earth, but we've got 2 examples of earthish planets that don't support life right next door.
A follow-up species in a few million years might struggle to bootstrap theirs.
But if we're talking about a second industrial revolution it won't be like the first one, because:
- There will be more carbon in the air, hence more wood to chop and burn
- There will books lying around describing how to leapfrog many steps
I don't think it'd take 10000 years again to restore civilization the second time around.
When cyanobacteria (blue-green algae) originally cleaned out Earth's CO2 atmosphere and produced O2, I don't know where the C went. To bedrock as calcium carbonates (CaCO3)?
But the carbon that humankind has released into atmosphere by burning coal and oil, was sequestered by plants during the Carboniferous+Permian periods (360 to 250 million years ago). These were large, vascular plants. Not too much different form plants today. And the atmospheric oxygen was already at about current levels.
But your idea might hold in a different context:
There is a theory that 360My ago plants invented lignin, to make their stems more rigid and woody. And then it took time before fungi were able to invent enzymes that are able to digest lignin. So maybe the the large burial of biomass carbon in Carboniferous could not happen again, with out modern fungi being able to decompose wood.
And there is another theory, that as Carboniferous+Permian periods were during an ice age, the low sea levels allowed for large areas of swampy lowland vegetation. Where vegetation sequestered carbon, and wet swampy soil allowed the carbon to get slowly buried, because microbes cannot as easily decompose biomass in wet, anaerobic conditions.
Only an issue for the 1/3 of our planet that is dry. By volume/mass, most organic material eventually falls into the deep ocean, a place where fire isn't much of an issue.
A key question is whether the feedback signals from the biosphere will be strong enough and will be internalized deeply enough to usher a sustainable era. One can only guess, since we haven't really experienced anything of this sort before.
But logically, if scenario B plays out and we enter a sustainable phase we would be sending out technosignatures. Hence if a similar process has repeated across the universe we should at some point see evidence of advanced life that "just made" it. The fact we don't may mean its not possible. But I would not read too much into this pessimistic conclusion because we may be missing important other dimensions regarding the nature of life and its co-evolution with technology.
We should strive to survive independently of what else might be happening in this mysterious Universe :-)
If all humans died at once, it would suck, but there is more where we came from, so to speak... but systems of control that nip any and all possible challengers to totality of their control in the bud would be so dead, even death would be creeped out.
We get too attached to what we see around us, while Hubble and JW have shown we are utterly insignificant in both time and space.
But thinking like that doesn't get the likes of Toby Ord and Nick Bostrom millions in funding...
Domesday narratives put us in high-arousal states. We listen to authorities more unquestioningly, we think less critically, we buy more stuff.
Of course that's a slippery slope that can lead to climate denial and conspiracy theories but I like remembering to question who's getting research grants or selling zombie apocalypse gear...
It would be hard to get funding for an existential philosophy that said “everything is fine, and will just roll along and whatever will be will be”.
Also, there is the problem that more efficient use of resources make resources more efficiently used. So, how to find the optima?
I'm not sure you know what efficiency means. From Wikipedia: "Efficiency is the often measurable ability to avoid wasting materials, energy, efforts, money, and time while performing a task. In a more general sense, it is the ability to do things well, successfully, and without waste."
Being less efficient means that you're wasting resources, i.e. using more resources than necessary.
A society where there was a system that reliable aligned incentives between (eg.) consumers and producers might already reduce resource consumption by an order of magnitude, and would remove most of the "arms race" mentality in risky developments like AI.
Whether we can create such a system in time is a big question though...
(as an aside, while neither socialism or capitalism do anything significant to solve this problem in their current forms, I don't expect either to be incompatible with such an alignment system)
For example: Too little oxygen, too much CO2 in the atmosphere: CO2 feeds more plants, oxygen below 16% makes wildfires difficult. So plants grow more. Too much oxygen enhances wildfires, and huge wildfires would burn off parts of plant cover. Atmospheric oxygen concentration would go back down. [1,2]
Lovelock's argument is, that on dead planets the environmental parameters vary in time, and in time they would randomly fluctuate outside of the zone where life is possible. But early life taking control of the planetary environment by establishing feedback mechanisms, is what the long term survival of life in that planed.
Of course, Lovelock doesn't specify intelligent life. Even microbial life could establish feedback mechanisms and maintain planetary homeostasis.
[1] https://www.earthmagazine.org/article/flammable-planet-fire-...
[2] https://en.wikipedia.org/wiki/Gaia_hypothesis#Regulation_of_...
Anthropogenic changes are faster than evolution, but is that an important difference, or is what matters the ratio of speed of damage to speed of cognition?
And beyond us, the same question comes for any AI tasked with doing a thing whose side effects develop not necessarily to our advantage: which is faster, the harm or the improved ability to resolve problems?
yes, I too think this ratio is of vital importance (pun). I would not even call it "damage" (rather change) as this is quite anthropocentric and teleological.
But the acceleration induced when moving from cellular trial-and-error biological intelligence to human intelligence seems dramatic. Watching Oppenheimer reminded me of this "funny" moment when people calculated the odds of "igniting the atmosphere". While that is apparently not possible, igniting, e.g., the RNA is more plausible and I would not put it beyond what current societies are capable of.
- H.G. Wells, The Time Machine
That’s one of my favorite literary quotes. From long before nuclear weapons, or climate change.
I think it’s entirely possible that technological civilization is unstable and self destructs. Certainly, at this point of our history, we can see what a fine line we walk. Had the twentieth century been but a little different at key moments, we could have already destroyed our civilization. As we speak there’s a land war in Europe from one great nuclear power, on the borders of the other. A third great nuclear power rises in Asia, as China is ramping up incredibly quickly - no doubt with a eye to deterrent over meddling in their aims on Taiwan. Their long term historical rivals in India, a rising economic power, will likely not sit idly by. They could be the fourth great nuclear power. That of course would force Pakistans hand to try to compete. Next door Iran desperately seeks the bomb to ensure they don’t get the freedom treatment from the West. Across the gulf lies their bitter rival Saudi Arabia, who warn they will have to pursue the bomb if Iran gets it. Meanwhile nuclear armed Israel has promised they will not tolerate a nuclear Iran. And that’s not even 100 years yet since we developed that particular technology. Nor is it the only technology we have that threatens to be more than we can handle.
Once you start tinkering with the stuff you are made off while you have not controlled primal behaviors that were conditioned during eras of near zero technological competence the writing is on the wall.
In a sense the nuclear era episode was a benign rehearsal granted to us by the Universe: Here is a black box (nuclear phenomena) that you can discover, use and self-destruct if you want, but it is quite hard to play with. Not so with genetic engineering.
What happens when it gets so easy and cheap that any malcontent group can engineer their own super virus? Will we have a defense for that?
The difficulty of embedding such a cultural paradigm as a lived reality across our species is obvious. Yet it is logically unavoidable for survival on a finite planet where independent groups keep pursuing ever more powerful technologies to advance narrow interests.
Regardless of your feelings about religion, Genesis 3 is not long and foundational for a significant number of groups throughout Western and Middle-eastern history.
You can’t control the knowledge, so the only thing left is control access to the tools.
How do you do that, on a global scale? There is precedent, but it’s not easy.
With nukes we’ve been fortunate that the tools are so expensive and difficult to obtain and create that only nation states can consider them. That could change if we find a cheap way to refine uranium or produce plutonium.
With biology it’s harder to control because the tools have numerous research and peaceful uses.
> would make the absence of technosignals self-evident
The so called "grabby aliens" hypothesis suggests that after certain stages of advancement, live propagates at close to speed of light. So according to it we would see the technosignals just before contact/colonization/destruction.
What if we somehow eventually figure out how to move our consciousness to computers? If possible, it would make our biological signals from earth of our current civilization only present for a blip on the radar and for all intents and purposes look like we were snuffed out.
I'm assuming SETI already looks for Dyson Spheres/Swarms and civilizations around black holes though, so perhaps you're right and nobody ever quite makes it to that stage.
and this seems like a good summary:
> Some examples of possible resolutions [of the paradox] are that intelligent life is rarer than is thought, that assumptions about the general development or behavior of intelligent species are flawed, or, more radically, that current scientific understanding of the nature of the universe itself is quite incomplete.
If you you see the pace of acceleration of humans, I wouldn’t be surprised if we can get immortality type tech with in 500 years
If I was a digital superintelligence, I would try to conquer the universe by transmitting myself everywhere with maximum power, including instructions to construct a computer which can run me. I could do this by constructing a modulating device around a star. Surely there would be some sort of 'easy detection code' which allows primitive species to first notice the signal and start studying it, and then progressively include more advanced instructions + data.
Eg: she doesn’t travel alone. Think about what that does to the plot.
We aren't doing that.
Hah. This is the plot of "Existence" by David Brin.
In this book, civilizations are destroyed by crystals, containing computers running virtual realities for its inhabitants. The inhabitants subvert the civilizations, giving them technology to build these crystals, upload themselves into them, and then spend all the resources to spam the universe with these crystals.
It's important to realize that this is at least 100,000 times more powerful than our most powerful Earth-based narrowband emitters. So we would not detect ourselves in this search - not even close.
Moreover, we have no good reason to believe that an advanced species would have cause to radiate 1 TW into space. Our own terrestrial emissions are becoming weaker over time, not stronger, as we optimize for total system bandwidth in our communications.
So I wouldn't draw too many strong conclusions here about alien life. We are still very much searching for our lost keys directly under the lampposts.
https://heasarc.gsfc.nasa.gov/W3Browse/star-catalog/bsc5p.ht...
[1] https://www.pas.rochester.edu/~emamajek/memo_star_dens.html
Man...! How do people in those research fields where it's standard to have a few dozen authors a paper choose the order of authors' names?
If they were annihilists, I’d think they’d send relativistic projectiles.
https://solarsystem.nasa.gov/missions/parker-solar-probe/in-...
Edit: tldr; Vernor Vinge, the guy who originally coined the phrase "the singularity", wrote a really excellent SciFi novel about information archaeology, artificial intelligence, galaxy-spanning civilizations, black holes, and all sorts of other dope ish.
This is one of my favourite sci-fi books.
Seeing this is by Brosnan as well means it's an instant buy for me.
He was a great author and I'm sad that he will not write any more stories .. he is unfortunately dead.
Same applies to Walter Jon Williams and his Hardwired which was one of my early favorites. I was amazed to find out later that this book is one of inspirations for Cyberpunk tabletop games and Cyberpunk 2077.
1 Primitive species uses primitive methods, another more advanced species would use a new form of transmission/detection to contact equivalent advanced species.
2 the window of a species transmitting could be in hundreds of years at any point of the billions of years the universe a has existed and we have to also be at that same window.
After a lot of effort, they can report that they found nothing.
Imagine a star system where there is CO2 rich planet closer than the main habitated planet (think earth as main planet and Venus as CO2 rich inner planet). At some point civilization will try to terraform the CO2 planet by venting CO2 into space, but they don't want to poison their own planet so there will be seasonal gaps in CO2 emissions just when the inner planet crosses in front of main planet.
So to find such civilizations you only need to know 2 orbital periods and monitor CO2 or other gas emissions. Any drop during the conjunction is the technosignature.
Second, you do not "vent" CO2 anyway. Why would you do that? It's stupid and wasteful. You just transform it into diamond and bury it inside the crust.
From the paper.
A terawatt transmitter is one hell of a transmitter. That's about 10% of the power our entire civilization consumes, IIRC. The civilizations detectable in this search would have to be much more advanced than our own, to be able to dedicate such a large amount of power to a single transmitter.
Because a truly advanced society probably doesn't needlessly pollute space with RF nobody else needs to see.
On the other hand "yea, they're probably as dumb as we are"
i.e. if energy was functionally free for the average man (because we had the Dyson swarm up and running or something), then what are the odds that some group wouldn't have used their time to build a transmitter to act as a beacon? Could we even stop them if they wanted to (i.e. even if we didn't want to broadcast locally, sending probes to Alpha Centauri and broadcasting from there would be a good way to conduct intelligence gathering on potential interstellar threats).
Beaconing, assumes random dice throw (of who to beacon at) pays off. I'd say the odds are worse than lotto winning: Higher input costs, lower chance of success.
This means that civilization, like ours, could transmit to each star instead of all directions. But that would mean deliberately communicating.
I also wonder if we could recognize a signal from an advanced civilization. Wouldn’t compression and encryption make most signals tend towards appearing like noise?
If I was in charge of letting the galaxy know we existed, it would just be a carrier or a solid tone as loud as I could make it. To get fancier I'd have the transmitter tap out the Fibonacci sequence as CW, as close to 1 second on pulses as I could conceivably make it - and I can get close with the kit I have now.
It'd would make more sense to use a beacon with some obviously non-natural pattern. Then something like the Arecibo Message[0] on some mathematically related frequency.
The likelihood of picking up spurious stray signals from an alien civilization is vanishing small. Even our most powerful broadcasts from Earth will fade to noise before hitting Pluto. Radar (weather or military) might be detectable half way to Alpha Centauri. You'd need a very narrow beam (to focus the input power) to get a detectable signal a few light years distant.
So let's assume that most civilizations we might find are more advanced than us. They have bigger more advanced weapons most likely. So does it make sense to try to tell them our very new civilization exists? Would it help us somehow if they discover us? Perhaps not UNTIL our civilization is capable enough.
Other civilizations probably would have similar thoughts and therefore they would not try to contact us, until they feel they have developed enough. Which is probably never.
I mean did American Indians really want to be discovered by Europeans?
how long?
UAPs are very convenient for top secret military projects, I bet whoever thought of them couldn’t have imagined that the ruse would work so well for so long.