Slashdot Mirror
The Fermi Paradox is Back
nettxzl writes ""Sentient Developments revisits the Fermi Paradox which is "the contradictory and counter-intuitive observation that we have yet to see any evidence for the existence of Extra Terrestrial Intelligence (ETI) although the size and age of the Universe suggests that many technologically advanced ETI's ought to exist." Sentient Development's blog post on the Fermi Paradox states that "a number of inter-disciplinary breakthroughs and insights have contributed to the Fermi Paradox gaining credence as an unsolved scientific problem" Amongst these are "(1)Improved quantification and conceptualization of our cosmological environment, (2) Improved understanding of planet formation, composition and the presence of habitable zones, (3) The discovery of extrasolar planets, (4) Confirmation of the rapid origination of life on Earth (5) Growing legitimacy of panspermia theories" and more ... So, where is everyone?"
o Far away in space
o Far away in time
o Far away in space and time
o Hollywood
In the immortal words of Douglas Adams, "Space is big. You just won't believe how vastly, hugely, mind-boggingly big it is. I mean, you may think it's a long way down the road to the chemist, but that's just peanuts to space."
The problem isn't that there isn't anyone else out there. With so many billions of stars and planets, the odds that there are other intelligent beings out there are astronomically large. (Pun slightly intended.) The problem is that the distances required to travel to reach them and also astronomically large, and the odds that there is life on any given planet are infinitesimally small.
I always put this thought experiment before people: If you had a spaceship that could instantly take you to anywhere in the universe, where would you go?
Sure, you'd probably drop by a few nebulae and stars and even planets, but after you've seen a few, where to then? You could travel to other planets for lifetimes and still not run across intelligent life on other planets. It's not that truly interesting things aren't out there, it's just that the universe isn't very conducive to producing life-bearing planets. Sure, with so vastly many planets, it will happen (and obviously has), but finding life out there is like finding a needle in a haystack, and we're just now starting to be able to see the haystack.
Further complicating matters is that we don't have spaceships that can instantly take us anywhere in the universe, and according to the laws of physics as we know them, it's likely that other intelligent beings don't either. Maybe they have travelled lifetimes and they just haven't run across us yet.
So be patient, my fellow humans, it may take a few million (or even billion) more years. After all, it's more than just a trip down the road to the chemist, and something that cool will probably be worth the wait.
This is it folks, this planet is all there is. God only created life here on earth.
So we've used a few hundred years of technology for almost a hundred years to look for signs of life in a (nearly?) infinite universe and not found anything. Must mean its not there.
Considering the state of terrestrial intelligence, maybe any ETIs have realized that broadcasting attack coordinates into space may not be such a great idea?
lol: You see no door there!
Steven Hawking's comment (about how the history of advanced civilizations on Earth meeting less-developed civilizations has generally not gone well for the less-developed ones) would seem to apply here. Hopefully, any civilization advanced enough to not blow itself to pieces before developing interstellar transport capability would be reasonably benign -- but can we afford the risk? If a civilization has the wherewithal to visit other star systems, they are at the very least many years beyond where we are, both technologically and economically.
Maybe we should be glad if we're too insignificant to be noticed just yet. (We certainly don't have our act together, at any rate.)
Paleotechnologist and connoisseur of pretty shiny things.
Anyone remember who first noted that the best evidence for intelligent life in the universe is that they haven't contacted us?
We've been unable to make our presence known by radio until less than 100 years ago.
We can get humans to the moon, but not to the next planet.
The universe is vast even compared to our oceans and we lose people in our oceans all the time. Why would we think a space probe would be noticed by someone?
Now, our technology will improve and some of the above statements may change rapidly. But, the chances of our using some of those technologies to destroy ourselves seem to be accelerating as well. Perhaps the missing part of the model is that other civilizations always blow themselves up within a few hundred years of their first communication attempts or steps off their planets.
We probably will.
I'm reminded of an argument put forth in Robert J. Sawyer's Calculating God: If, once we reach a certain level of technological sophistication, it takes only hundreds or thousands of years to either annihilate ourselves or transfer our consciousness into a virtual world, what are the chances that any two types of intelligent life could exist contemporaneously anywhere in the universe, provided that a sufficiently intelligent species develops science and technology only after developing for several billion years?
We're not even confident that our social experiment will last right now. We've had 120 years or so of real technology -- and there's no guarantee that resource constraints, political strife, or any number of environmental factors won't return us to subsistence farming within a few more generations. The real question is, given not only the incredibly large size of the universe, but also the almost incomprehensibly-long timelines, what are the chances that two intelligent species will be concurrently intelligent, civilized, and looking for each other ... and furthermore, what is the chance that we are one of them (and at this very moment)?
True science means that when you re-evaluate the evidence, you re-evaluate your faith.
Assuming they're smart enough to create signals that we can detect, they can most likely detect ours too.
Complex life on this planet has been going on for hundreds of millions of years and yet it's only in the last hundred or so that we've been able to look out with anything more than enhancements of our natural senses. This implies that the odds of a second species being at exactly the same point tiny. Most likely, if they're sending things we can read, they got there a long way before us and are quite a bit smarter.
Assuming they're quite a bit smarter, one look at the crap our radiowaves are sharing with the universe - infomercials, reality TV and our politics/wars - and I'd imagine pretty much any higher civilization would be embarrassed enough about us to screen their signature and make damn sure those idiotic hairless apes don't go and screw their part of the galaxy up too.
So, the answer to the paradox: There's most likely higher intelligence out there. And, because it's higher, it's most likely embarrassed to hell and back by us and screening itself from us. Problem solved.
Any space-faring race that makes it here will be technologically advanced by far.
We're technologically advanced over all the other creatures here on Earth. We eat them.
--
BMO
Maybe they are out there, trying to communicate with us, but they're using MSN Messenger and have the same bad grammar as half of the other people who use it?
"hello earthling.we want to know you know about us.info is important!!!!!"
I always found it puzzling that the brightest minds seem to feel there's a fair percentage chance we'll find sign of extraterrestrial intelligence from radio waves. Granted, they're a lot more clever than me, so hopefully they have good reasons.
My view though...
Our civilization is in its technological infancy, and even we find radio rather slow and limiting. I can't imagine us leaving much of a radio footprint in another hundred years, especially not leaking it with omnidirectional broadcasting.
Imagining the same being the case of another civilization, we're trying to listen in on broadcasts from a time window of two hundred years or so, and we've been listening for a couple of decades. In a context where being off by a million years wouldn't be too bad, the odds strike me as fairly infinitesimal even if assuming thousands of civilizations located cosmically nearby.
Doesn't hurt to try, mind. It's not like we have a lot of other options open to us currently.
Our radio emissions are a powerful repellent to intelligent life. Come on, if you tuned in to earth and heard all about Paris Hilton, Disco, or one of FDR's "fireside chats", wouldn't you just keep on going by?
-jcr
The only title of honor that a tyrant can grant is "Enemy of the State."
With so many billions of stars and planets, the odds that there are other intelligent beings out there are astronomically large. (Pun slightly intended.)
That's the Sagan argument. Unfortunately, the fact that we exist tells us absolutely nothing about how probably intelligent life is or isn't (see: anthropic principle). Sagan's argument doesn't address the fundamental Fermi problem.
The problem is that the distances required to travel to reach them and also astronomically large, and the odds that there is life on any given planet are infinitesimally small.
True, but the amount of time that's passed until us showing up is also astronomically large. It only takes one race with an expansion desire to fill up the galaxy at sublight speeds around 1 to 10 million years (via geometric expansion). Even if it took 100 million years, that's still a blip in the life of the galaxy. At the very least, someone should have sent out self replicating probes by now. By we've seen absolutely nothing.
I'm pretty much convinced that intelligent life is extremely improbable, and that we're alone in the galaxy.
Sometimes it's best to just let stupid people be stupid.
I found a video from these guys to be rather interesting, if not somewhat convincing: http://http//www.disclosureproject.org/ Video can be found here. Please, anybody with some web space, put up a mirror so that this nice little not for profit group doesn't get slashdotted off the web: http://www.netro.ca/disclosure/npccmenu.htm
The paradox is that if they have a few thousand or hundred of thousand year ahead of us, then they should have at least by probe or similarly conquered or explored this galaxy, or send a lot of radio signal.
My girlfriend pointed out that we've been analyzing for hydrogen based signals, because it's the easiest to produce, and we've found nothing. And then it came out in the conversation that WE'RE not sending out signals because we don't want to be found because we're not advanced enough to protect ourselves from someone who could find us.
Ahem. So in 10k years, we'll be advanced enough to defend ourselves from these theoretical people who are 10k years ahead of us? Will their civilization stop advancing, and we'll catch up? How about maybe aliens aren't sending out signals either?
How about maybe, just maybe, the way we developed science is not very efficient afterall in the grand scheme of things?
I love it when people argue the existence or non-existence of super-advanced beings based on our assumptions about how right we are about everything.
Please stop stalking me, bro.
Indeed, as TFA notes, there is "something wrong with our thinking", or at least with that of the author.
First, interstellar colonization? Unlikely. It makes nice SF, but there's no good economic basis for it. A civilization that survives long enough to reach the technological level necessary for interstellar spaceflight will have stabilized its population and learned how to use local resources to make their home world a paradise. Why go anywhere else? The expense is enormous, the payoff non-existent. (They're working on stellar engineering, of course, so there's no worry about their sun going nova.) Childish species who still imagine faster-than-light loopholes might dream of going swashbuckling across the galaxy, but grown-up races are content to follow more mature pursuits. TFA's claims about "intelligent life's ability to overcome scarcity, and its tendency to colonize new habitats" are simply handwaving, generalizing from one species of half-bright monkeys into sweeping statements about all intelligent life.
Second, there's the question of signal detection. Contrary to popular belief, radio and TV transmissions probably couldn't be detected at interstellar ranges. We've only sent a handful of signals into space that are detectable at long ranges - and mostly that's content-free radar signals. Why do we assume others are more chatty than we are? I imagine a galaxy full of listeners, each waiting for someone else to start talking. Additionally, compression and encryption make signal indistinguishable from noise.
Third, recognition of "mega-engineering". TFA claims "we see no signs of their activities in space". How would we know? We assume a "natural" explanation for phenomena - as we should - but if we assume the existence of greatly advanced tech, who knows what we think of as "natural" and take for granted out there that's actually engineered?
Tom Swiss | the infamous tms | my blog
You cannot wash away blood with blood
Even if there was proof of ETI our governments would cover it up. Is it really a paradox if we have no chance of obtaining proof?
One piece of wild speculation on why we haven't accidentally picked up any TV or radio broadcasts from ET...
At this point in time TV and radio is rapidly being usurped by interactive media, most of which currently travels along cables and would of course be undetectable from other planets. As for wireless internet, the power of a wireless LAN router is obviously far less strong than say a TV signal broadcast from a TV tower. And future wireless broadband signals would presumably also be local and low-powered, because it's more efficient that way. (Guesswork, of course).
Of course traditional high-powered TV and radio broadcasts aren't dead yet, but in say 100 years it's pretty easy to imagine that they they might be. (Or not -- I know this is all speculation)
So, IF (huge if) other civilisations follwed this path, this might be a possible reason why we don't see or hear their broadcasts -- because like us their high-powered broadcast media only existed for a short time, and were soon replaced by more efficient low-powered interactive media
All wildly speculative I know.
Out of all the different possibilities of why we haven't made contact, I tend to think it's not that intelligent life doesn't exist, or that they don't care about us, I think it's that they do care, and that's why they're leaving us alone. It's akin to us protecting the animals of this planet, so they can continue to exist and spread. It's quite possible we're under protection also, until we can fend for ourselves.
"we've got trenchcoats and bad attitudes" - John Constantine, HellBlazer
It behooves us to consider Fermi. The idea is indeed seductive.
On the other hand, just because WE don't usually quite make one hundred years of consciousness, we assume all things told, that six BILLION is old, and Thirteen Billion is even older.
One thing no one has pointed out yet. What if that is YOUNG? Vaunted as he was, Fermi didn't include that as a possibility. He either didn't see it, or discounted it. What if we're the FIRST major civilization to grow? Or, let's use our own development as a yardstick. It took us, what seventy five years? to begin putting the broadcast entertainment onto cable, and stop actually advertising our existence. It won't be much longer, and our planet will be nearly invisible.
Now, if technology develops the same, no matter WHEN, but THAT, it would have taken a hundred years, roughly, for the civ to develop broadcasting, use it, and then, as we are doing, turn it inwards, and not waste power in exo-broadcasting.
So, any star roughly a hundred light years out would be able to pick up our signals, but if their civ had gotten a start a thousand years before ours, well, then, we missed their shows by a millennium. Talk about the need for TIVO.
My point is simple. We assume any civ out there is attempting to get our attention. If they developed like ours, even starting the same day, we won't see them at all, UNLESS they are at the right distance. Otherwise, we won't see their signals, as it already passed us by, or the leading edge hasn't hit us yet.
We won't even go into the many different and varied methods we ourselves use to communicate that never beak the atmosphere, thus making them exo-undetectable. Fermi's assumption is a classic illustration of of assuming... You know, making an @ss out of you and me?
I was talking about this with a coworker a few weeks back and realized something. Back when radio was first discovered they used *huge* transmitters to transmit a small amount of data a short distance because their receivers were so crude. Later receivers were vastly improved and you could use much lower power to send much more data. Soon we had over the air TV that had a phenomenal amount of data flowing through the air, but, to not encroach on competing channels in adjacent areas, the signal strength was reduced again.
Skip forward to today and we are using cable (very little "signal" escapes) and fiber-optics (no signal escapes) to send even more data back and forth. So, in a few years time we've gone from a very noisy planet with out much to say, to a much less noisy planet with much more to say.
I think it is inevitable, simply from an efficiency perspective, that we will be using more and more "tight-band" communication methods in the future (quantum entanglement?). It seems intuitive that the more advanced a civilization gets the more efficient it will strive to be. The more efficient it is, the less noise will be wasted into space (especially compared to the natural noises of the planet, like lightning, aurora, etc.)
Look how much more efficient we've become in just a hundred years. If this is indicative of other civilizations, then the window of opportunity for eavesdropping on them is extremely small. And that's assuming that they are remotely like us and not building their civilization at the bottom of their ocean or are just so different from us that we wouldn't even recognize them as life.
As far as colonizing the stars goes, barring some way of FTL (or instant) travel and communication, I think we will never move beyond our own solar system in our current physical form. I think we will have figured out how to lose our bodies and move our consciousness into "the machine" before then. Once that happens, there will be no need for maintaining the human race in a biological form at all since "reproduction" can occur in solid-state. Once we've reached that stage, being effectively immortal, we might be willing to entertain the thought of physically traveling to other stars, but there will be no need to colonize them, they can be virtualized. But then again, we could virtualize the whole trip anyway.
Either way, that step in technology would almost guarantee a very efficient system that would need to produce almost no waste products. With no need for maintaining and supporting physical bodies, all of the energy required to sustain physical life will not be needed. No more growing and shipping crops. No more energy wasted in physical travel. In fact, very little need for ever physically moving anything, from then on. This would make most of our civilization a "static" construct. At that point, unless we were purposely broadcasting for neighbors, who'd ever hear us?
"terrorism" and "pedophilia" are the root passwords to the Constitution
An important idea in the panspermia theory is that when a star goes nova, the biomass is not totally eliminated. Some fragments remain. When new stars and planets coalesce around the remnant masses those become the seeds for a new generation of life.
So according to that theory, we are the alien life forms we're looking for, in a certain sense.
If mankind is to persist another thousand years we'll have to solve a number of important puzzles. To survive a hundred thousand we'll have to solve many more. By then the pointlessness of immortality as a species may be self evident.
Any civilization sufficiently advanced to come here in force from another star has solved the energy, food and mortality puzzles, which leaves conquest unlikely as a goal I should think. Why take the trouble to scrap it up with a pestilent life form at the bottom of a steep gravity well when mass and energy are abundant in the oort cloud and asteroid belt free for the taking? Why travel all the way to another star just for that since those things are doubtless abundant where you came from?
I think what's left is tourism. Intelligence and curiosity are sufficiently linked that a life form evolved enough to solve the necessary problems would want to watch us develop if they could. Perhaps they're here now, secretly recording our ridiculous antics for their own version of reality tv.
Help stamp out iliturcy.
Of course, the problem with the 'everyone's listening' argument is that it requires everyone to be listening. Even if only 1% were actively transmitting, we'd expect a lot more signals than we've found.
I am TheRaven on Soylent News
I'm pretty much convinced that intelligent life is extremely improbable, and that we're alone in the galaxy.
What an extremely narrow and self-centered view of the universe.
First of all "extremely improbable" when talking about something the size of the universe means that even if life in a given star system had a 1 in 1 million chance of ever developing (I'd call that "extremely improbable"), that's still 5,000 systems in our galaxy alone that will develop life someday, or already have. For a 1 in 1 billion chance, that's still 500 star systems. And there are up to 500 billion galaxies in the universe. Even if only 1 out of every billion star systems will support life - or perhaps 1 out of every 5 billion planets - that would still mean there could be trillions of life-supporting star systems in the universe. Given that there are not one, but two planets in our system that are capable of supporting life (Earth and Mars), both of which may have actually supported life, it's certainly no stretch to think there are at least this many planets out there that could support life and that at least some of them are actually doing so.
It's all too easy to draw conclusions for the entire universe based on observations of your local area. People do it not just when thinking of extra terrestrials but even when thinking of other people and cultures on our own planet. There's a tendency to think that the way we do things is just the way that things should be done. But there are many ways life can develop, many ways life can be supported, and many, many planets that are much too far away for us to observe or for them to observe us. It's foolish to think that we are alone simply because we have not observed any other intelligent life in the few hundred years we've been looking.
Maybe other life forms have sent out self replicating probes. Why would we have necessarily noticed?
This is one of the most likely reasons we've not "seen" anything as yet. As far as we know, interstellar travel is annoyingly slow and energy intensive; that alone could account for no visitors, no matter how well populated the universe is with intelligent beings. That leaves communications; but our experience here indicates that catching the communications of others is very unlikely. Why? Well, we've been hanging about for 50,000 years or so in the form we like to consider actually "us." Of that 50,000 years, we've been using radio and television for about 100 years now. But in the last 25 years, more and more of our radio and television signals have been finding their way into satellite to ground signals, which do not radiate away from the planet and are very, very low power; other signals are now traveling inside cables instead of the through the air; and finally, newer communications are moving to optical methods, and we're talking optical in cables for the most part, meaning again, less and less high powered "accidental" signal radiation (effectively zero in terms of interstellar distances.) The reasons are higher bandwidth, vastly more communications channels, more energy efficient, better control over where the signal goes - and doesn't go. These are reasons that transcend our civilization; there is every reason to think that other beings would find the same benefits.
Next, look at our development: We're paranoid. We have been prey for a lot of living things ranging from other people to lions to snakes to spiders to bacteria, consequently we're not of the mind that the universe is likely to be a friendly playground. You can find reactions to that notion everywhere from science fiction to the unwillingness of today's moms to let their kids play outdoors unsupervised. Looking at our SETI program, the first thing you probably notice is that we're listening (poorly), which seems prudent; but we are not intentionally transmitting a signal to the stars, which has been a political decision. That leaves the accidental radiation, the strongest of which has been radar transmissions, which are mostly information free... but even if they're enough to get us noticed, we've only been at this for a 100 years, so our signals are only 100 light-years out so far. That severely reduces the number of potential listeners, and of course it presumes they, like us, are listening for anything, not just signals modulated with complex information.
Also, as an earlier poster observed with a quote from Douglas Adams, the universe is gi-flipping-normous.
All of this contributes to why Fermi's Paradox should be considered Fermi's Blunder by anyone who really thinks this through.
I see no reason to doubt there are plenty of other life-bearing planets out there, and that a fairly significant number of those in turn have intelligent life of one form or another. The fact that we've not "heard" any of them doesn't surprise me one little bit, Fermi's naive reasoning aside. In another 100 years, the odds of us radiating anything at all from our little corner of the universe are probably very low indeed. If that's typical (and it may be longer than typical), then in order to "catch" someone else transmitting by accident, we'll have to be listening at the same time + distance in light years that they go through the RF development process, and we'll have to have sensitive enough equipment to hear them. That last point is interesting, because although technically speaking, we are listening for "them", we're presuming they're sending at the low-noise point of the spectrum with the intent of us hearing them. If it was accidental radiation like radio and TV we were looking for, we couldn't hear that with our current gear at all. In order to get to that level of sensitivity, we'll need outer space "ears", and pretty big ones. Nothing like that is even on the drawing boards. So again, the odds of us hearing anyo
I've fallen off your lawn, and I can't get up.
Assuming a civilization was advanced enough to be able to travel and communicate galactic distances, they would also have long ago realized what we only recently learned, which is that the Andromeda galaxy is due to collide with our own in about two billion years. Probably not much they could do about that, so they charted out another more hospitable galaxy and took off. So long and thanks for all the fish.
No-one thinks that the earliest form of life involved DNA (or anything like it). The simplest form of cellular metabolism would basically have been a self-replicating chemical soup that "consumed" chemicals in the environment in order to create more of it's own chemical constituents. This type of self-sustaining chemical microenvironments likely occured all over the place - before they ever became separated from the rest of the environment by any cell-like container.
The earliest cell-like containers may well have been simply lipid (fatty) bubbles that presented a semi-permiable membrane that let certain chemicals thru. These types of lipid bubble could easily have formed naturally (think froth at the edge of the ocean), maybe even based on products of these chemical reactions. There's no need for the earliest "cells" to have been created/encoded by the chemicals they contained as they are today (DNA).
The earliest forms of replication also need not have been self-encoded - they would almost certainly have been due to physical processes - e.g. if you whipped up (sea-shore wave action) a bunch of large fatty bubbles, you'd get a lot of smaller fatty bubbles which would then "grow" via their semi-permiable enclosure letting in the external chemical components that "fed" the chemical reactions. Similar to how an amoeba )modern single cellular organism) "reproduces" by splitting into two.
Highly complex chemicals like DNA or RNA may have have originated as simple chemical catalysts that sped up the reaction process - i.e. guided it rather than being part of it per se.
These types of extremely simple pre-cellular origins are far from being low probabiliy events - they are alomost inevitably going to occur given a rich enouch chemical environment and suitable phyiscal conditions (water, wave action = stirring, lightening, sunlight, etc). If you're interested in the beginning of life at this extrememly early stage, try reading Stuart Kauffman's "At Home in the Universe".
Even at this early stage, evolution would necessarily have occured. Among multiple such self-sustaining reactions, those that were best adapted to the environment (those parts of it they relied upon, e.g. available chemicals) would necessarily have left more "descendents" than others that were competing for the same raw ingredients (food supply). With these types of lipid membrance cell, new chemicals in the environemnt that were not part of the chain reactions occuring in the "population" would often have been introduced, and occasionally would have modified those reactions and their products. This source of variation would then have been fodder for natural selection (the winners swamping the losers out of the environment), and so it goes...
Read through the list of nations that are part of the U.N. Some of them count as bad neighborhoods, and they still have a presence on the global scene. You started with an image of a Utopian galactic society, and I can't figure out why. Why would you assume that the rest of the universe is so much better than us? Why would you assume that drugs aren't widespread to help lower the effects of culture shock? Why couldn't a military ruler exist in such a system? Even nonsentient species on this planet understand self-defense. Build up enough military power that whoever or whatever is out there can't impose their will on us seems like a valid argument for a leader on any stage.
And how can you make sweeping statements about as of yet imagined beings and their society, and be condescending to everyone who isn't partaking of the same fiction?
I see your informative link, and raise you a pithy comment.
Glad to see everyone has solved the Fermi Paradox just by reminding us that space is big and by quoting Douglas Adams ad nauseum. Guess we can close the book on that one. No Python references for us? I think that would sew it up tight.
Sarcasm aside this thread has so much supposition about the intelect, ability, advancement, logic and morality of any possible alien life it's mind blowing, and not in a good way. I don't think we can presume to understand an alien intelligence even if it did show up.
I've read some comments that proposed that if an alien life form advanced enough to actually mobilize the technology to reach us that they would be so intellectually superior that they would have no interest in us, or at least no malevolence towards us because they would be so enlightened. That's a massive guess that puts a lot of faith in the development path of "intelligent" life. If you think of Humanity as a possible median point for cruelty and benevolence (as we often paint ourselves in Sci-Fi), that still leaves a lot of terrifying room for a bad encounter.
Anyway tl;dr it's a paradox. It's genuinely weird. There's no simple explanation. Space is big, but life should be plentiful if the explanation of abiogenesis holds (local chemicals spontaneously live). It should be plentiful if the explanation of exogenisis holds (space junk has space mold)? Dammit it's just weird!
-- The unsig...
Provided that one model of the inevitable course which all civilizations must absolutely follow is true.
You made one crucial mistake in the above... it doesn't take "all" civilizations, it takes only one. Only one civilization has to either want to expand throughout the galaxy, or wants to create self-replicating probes to explore the entire galaxy. Assuming intelligent life is relatively common, do you think it's reasonable that not one over the last few billion years would do it?
Sometimes it's best to just let stupid people be stupid.
Even more irksome is when people make sweeping statements about things supposedly missing from science fiction that has in fact been extremelyv thoroughly explored over the decades.
(And trying to be slippery by qualifying with "run-of-the-mill" doesn't help, since that amounts to a circular reference -- if a story does address non-radio-signal communication, then it doesn't count???)
Even in the earliest "space opera" stories (e.g. E. E. "Doc" Smith and his cohorts) in the 1930's outright assumed that advanced civilizations would use telepathy, tachyonic communication, etc., and it was not rare even then to suggest that they had more or less forgotten about ordinary radio waves as hopelessly antiquated.
Decades ago there was one particularly amusing story (author and title forgotten, alas) with a series of vignettes, each suggesting a different and clever explanation for the Fermi Paradox e.g. one civilization was trying hard to communicate with Earth in particular, but they kept assuming that their data rate of e.g. one bit per year was too fast, so they kept slowing the rate down.
A very funny story (which I think is actually available online, these days) talks about the incomprehensibility, to members of a far-flung multi-species galactic civilization, of Earth having beings that "thought with meat", as opposed to every other galactically-known species that had brains of plasma or electronic etc. nature than were otherwise known. (This was not directly about SETI issues, but such are strongly implied.)
The ultimate problem is not a lack of imagination -- many, many exotic notions of ET communication have been considered -- but rather that the exotic modes are not pragmatic. If ET's communicate with tachyons, well, alas, we don't even know for sure whether tachyons exist or not, let alone how to try to receive them from ET's.
Interesting recent example: in quite recent years, it turns out that there is a previously-unnoticed theoretical prediction from quite orthodox physics, that photons can carry, not just their intrinsic spin of 1, but also an arbitrary number of additional units of angular momentum. This seems to be little-known, so far, and no one knows how to either produce or to detect that additional angular momentum in photons.
Nonetheless, many people immediately speculated about 2 things: whether cosmological events may produce such photons, and whether ET's might produce such photons.
Failure of imagination is not the problem. The problem is the pragmatics of turning imagination into a realizable experiment.
You complain about the failure of the imagination of SF writers, futurists, etc, but what that says to me is that you are unaware of the rich imagination long ago represented by such people.
Perhaps the problem is merely that you read only "run of the mill" or mediocre fiction and futurism, hmm?
Professional Wild-Eyed Visionary