Fantasio
One of my commonly made arguments against the likelihood of finding extraterrestrial intelligence is that it seems to be remarkably rare on our planet — I’m not making a joke about Republicans (although I could), but am stating a fact, that in the half-billion year history of animal life on Earth, only one species has followed the evolutionary strategy of extreme reliance on technology, ours. It doesn’t seem to be a common way for complex multi-cellular organisms to succeed, so we should expect that even if that kind of life is common on other worlds, it’s not likely to produce organisms we can talk to.
But what if I’m wrong? What if intelligent life had arisen on Earth multiple times? Would we be able to recognize it in the geological record?
Forget about the SF tropes of finding the equivalent of the Statue of Liberty on a beach somewhere, or digging up a transistor radio. All the monuments and all the toys we’ve built would be crumbled away and ground into dust in a million years or so. But what about chemical traces? We’ve been pumping out all kinds of novel chemistry, maybe some bits of it would leave a signature behind for our successors to discover.
That’s the question asked in this article by Schmidt and Frank. What should we look for?
If an industrial civilization had existed on Earth many millions of years prior to our own era, what traces would it have left and would they be detectable today? We summarize the likely geological fingerprint of the Anthropocene, and demonstrate that while clear, it will not differ greatly in many respects from other known events in the geological record. We then propose tests that could plausibly distinguish an industrial cause from an otherwise naturally occurring climate event.
Like they say, there’s a fair amount of uncertainty — on a geological scale, we don’t know how long industrial byproducts will linger. Stuff like plastics and halogenated organics might persist for a long time, in the right environment, such as after being buried and sequestered. Maybe we should look in ancient sediments for compounds that are likely to have been produced by a technological society.
In a real twist, the authors also wrote a science fiction story about such a search. What if we found PCBs and transuranic elements in a deep stratum, and what if it was also associated with an abrupt change in climate or the biota of the time? How would scientists interpret that?
What I found most chilling, though, was the long list of unexplained, abrupt climate shifts they describe in the geological record. Worst case scenario: what if they were all caused by the appearance of species that achieved some kind of global dominance (not necessarily technological) that led to a brief period of self-defeating triumph that always led to their inevitable extinction?
I think I just gave myself nightmares. What if we launched a SATI (Search for Ancient Terrestrial Intelligence) program, found multiple instances, and learned that our peculiar niche is more common than we thought, and always leads to our decline and disappearance? Would that knowledge allow us to change, do better, and escape our doom, or would it tell us that any attempt would be futile?
Worse than finding Cthulhu would be finding it’s traces, and learning that it was long dead, it’s annihilation pre-ordained by its nature, as we will be.
Schmidt GA, Frank A (2019) The Silurian hypothesis: would it be possible to detect an industrial civilization in the geological record? International Journal of Astrobiology 18(2): 142-150.
My guess is our longest legacy would be that all the biogeography got messed up for just about every surviving taxon all at once, right to the point of having placentals take over Australia. But I guess that would be hard to notice in the age of Pangaea.
Us? No. We invented capitalism.
Oops.
Best case scenario. Maybe intelligent life has arisen multiple times, they eventually understand their impact on the planet, clean up really well, and go off into space to let the planet continue without them. (Yes, I know it’s dreaming, but it’s as consistent with the evidence.)
Bah. I just want to see aliens like the ones from The Mote in Gods Eye.
I think finding non-intelligent life on another planet would be just as interesting as finding intelligent life (and less fraught with danger). The only clear reason to search for intelligence is the assumption that they would be more visible in distant star systems, e.g. in the form of radio communication or stellar engineering. But I wonder what are the limits to finding a signature of some form of life in from spectral analysis of exoplanets.
All this worry about some extraterrestrials that will enslave humans is stupid. It already happened. The extraterrestrials are called cats.
The Great Filter is in front of us.
Regardless of the chilling prospect, it’s fascinating research.
we are not just looking for intelligent life or speculating about intelligent life we are looking and speculating about technological life that is very much with slight variations like ourselves.
Why are we looking with that restriction? Just look at what technological development does. Along with the survival benefits it gives humans it brings a progressively more destructive cost to the rest of biosphere until we reach the point where it is a threat to the entire climate of the planet and all of the current plants and animals now living ourselves included.
Would we even recognize intelligent life if it was not like us in that same way?
What would an intelligent life form look like that tried to make a positive impact or at least a zero impact on their environment, no urban sprawl, clear cut forests open pit and mountain top removal mining plowing up prairies and all of the rest of the things we do with and about technology.
We have every reason to fear rapacious evil aliens invading us from outer space if we think intelligent life is only going to be like us by definition.
uncle frogy
As I understand it, evolutionary advantageous things like eyes have evolved many times in many different form.
Which leads us to the question, if big brains are so great, why don’t more animals have them?
Probably not a novel thought, but I think that it was fairly easy to evolve ‘early’ intelligence on our planet. We have dolphins, chimps, and lets throw in elephants. But all but one of these lines had any ability to evolve to advanced tool use (hard to do much with flippers, for example). So why did other apes not advance? I suggest because we, being total bastards, killed them off. All those Austrolopithecine and Homo genera had to go. It is noteworthy as as bigger brained members of our line appeared, the smaller brained ones stopped leaving fossils.
So other planets with earth like conditions could also spawn life and some of those ‘early’ intelligent life. But then it would winnow down to one dominant species.
PZ: “in the half-billion year history of animal life on Earth” (where the hell do I find the code format for wordpress comments?
To be fair, that’s not long. Life has existed for 4±0,5B years, most of that time it existed mostly as slime. Are warm blooded animals older than 100M years? So maybe life takes 4B years to evolve something as complex as the human brain?
Looking at the rest of the animal kingdom, some level of intelligence isn’t that uncommon (I try to study the magpies at work, but sometimes I suspect they’re studying me). But most species simply aren’t equipped to utilize more brainz. Birds can make rudimentary tools, can you imagine them ever evolving into something that can use advanced tools?
Cephalopods could be even more intelligent, but what are the chances of them ever discovering fire?
And what about the orangutans? If we didn’t get there first I’m pretty sure they would get there in time. But sadly there is no room left for the runner-up.
Depends on how much time and money you’re willing to put into the search. Next stop should be one of the polar craters on the Moon, forever dark, shielded from electromagnetic interference from Earth, and mere yards away from an inexhaustible solar power source. For me, this is the most compelling reason for going back to the Moon — setting up observatories is near ideal conditions.
But, the plane of the inner Solar System is quite dusty, and the Zodiacal light reflecting off those dust grains will limit the resolving power of Moon based telescopes, and the only solution will be to send our telescopes far out into space, beyond the worse of the dust cloud — and likely fleets of interferometers working together to get the best images and spectra possible.
Expensive, yes, but a mere pittance compared with even a single interstellar mission, and will eventually help us created a database of hundreds of thousands of exoplanets, some of which will be favorably aligned with their host star to allow us to analyze their atmosphere. It won’t be easy, but this is the only practical way to explore the galaxy, so with all the usual caveats about the continuity of civilization, I expect we will cataloging exoplanets for centuries to come.
Because no matter how we evolved, we all live in the same universe and are bound by the same laws of physics. All the same obstacles must be overcome to become a technological civilization, and eventually a space-faring one, so while there will no doubt be big differences in physiology and psychology, and their social fabric could be very different, I suspect they won’t be so different that they will be utterly strange to us — we all share the common languages of maths and physics.
I disagree. Sure, there’s always a chance an alien civilization is driven by some crazed fundamentalist imperative to wipe all other life from the galaxy, but there are plenty of other reasons to believe such encounters are likely to be friendly. I don’t have time to lay out an entire thesis, but suffice to say that any civilization with the technology and resources to spread across the galaxy is likely to know pretty much all there is about the Universe already, and encountering other civilizations with their unique histories and cultures will be the only novel things left for them to discover. That, and they’re extremely unlikely to need to plunder our planet for resources — a favorite trope of scifi blockbusters.
@tacitus #13: Knowing what we know today: Traveling between the stars will require some real freaky-deaky science, by that time I suspect we would be able to utilize more readily available fuel sources.
The first step would be to convince the world about these findings and, well, you see how well we’re doing with climate change facts…
I am not suggesting that destruction is the goal as such but destruction is one of the most often ignored results of our technological developments. When we just selectively encouraged some plants to grow and discouraged others by planting them out in wider areas like we spread some nut trees further from where they had evolved it might be very low impact but then we invented the plow which gave us more food and a greater impact on the environment. the greater impact was not the purpose but it was undeniably one of the results. We discovered how to make fire and discovered many uses for it again increasing our impact on our environment.
why would all intelligent life need to do that to be considered intelligent.
When it could just as easily be considered an unintelligent and surly a short sighted thing to do and in the end as I understand the implications of the theses ultimately self destructive and leads to extinction.
why should a great apes or a cephalopods or whales need to build things to be considered intelligent.
we are not looking for intelligent life we are looking for some mirror of ourselves all else is beneath us
uncle frogy
I think any former technological civilizations would have left CERAMIC evidence. We certainly are: perhaps hundreds of millions of years from now, some successor intelligent species will marvel at our fixation on bathrooms. They may well call us the bathroom civilization, because the porcelain of our toilets should be at least as easily preserved as bones and shells.
@13 absolutely the only thing that would be unique about any planet with intelligent life or any life for that matter is how it has solved the problems of living on their particular planet and the culture that they adopted. everything else seem to be scattered around all over the place without gravity wells to contend with. except things like wood or coral or truffles
uncle frogy
The best sign that there basn’t been a prior intelligence on Earth is the lack of mineral extraction. Why aren’t there any pools of metal or trash similar to fossils? Unlike living tissue, heaps of extracted minerals would still be there a billion years later. No amount of tectonic activity could redistribute the elements the way we found them.
I think there could be other signs of a civilisation beyond that of a strata of plastics or transuranic elements. We’ve only been producing those for barely a century, yet for millennia we’ve been domesticating various animals and taking them with us wherever we go. The ancestors of domesticated cattle started off in the Near East and in India, and over the course of ten thousand years spread as far as the Americas and Australasia. There’s now a greater biomass of cattle on the planet than there is of humans.
Generally any cattle which died of disease or highly traumatic accident were (and in some places still are) thrown into a pit or buried where they fell, rather than being butchered and their bones spread. Wouldn’t this make them, in terms of numbers alone, likely to show up in the fossil record many millions of years into the future? Their sudden appearance in a narrow strata across all continents except Antarctica would suggest to future palaeologists that they were deliberately transported across the oceans, their bones giving little reason to believe they had the ability to swim or fly great distances.
Yeah, ceramics should do it. If we can find bones, surely we would have found ceramics. But what else could survive for say 10M, 100M and 1B years? And how certain are we that it hasn’t already been detected and discarded as a contaminated sample?
There’s only room for one (at a time). How long from the appearance of modern humans until we had a globe-dominating civilization? It’s a geological eyeblink. Where’s the opportunity for another technological species to arise on Earth? If they’d come before us (and survived), we wouldn’t be here now. If they came after us, most likely they wouldn’t have made it here yet; but if they had, we’d wipe them out, or maybe domesticate them, before their civilization got anywhere.
A probably extreme longshot would be finding evidence of their space program elsewhere in the solar system. It would require whatever piece of equipment somehow surviving things like meteorite impacts, and would probably be sheer luck to stumble across it. And of course if we did find remains of an ancient Earth civilisation’s moonbase we’d assume it was extraterrestrial.
I’ve played that game, it’s called Mass Effect. (Only the Old Ones aren’t exactly dead…)
As long as we don’t run into those pepper pots with the toilet plungers yelling, Excommunicate! Excommunicate!”
I’ve heard a couple of songs on this subject. Like this one about aliens finding a Voyager spacecraft a long time in the future, and tracing their way back here:
https://latheofheavenuk.com/track/1484943/the-last-song-wav
Is there intelligent life on Earth?
@13 @14
If ETs are traveling between stars at anything close to light-speed (and as slow as that is, it’s not inconceivable that you might want to send, e.g. self-replicating hardware and genetic material to colonize other star systems) wouldn’t these starships leave some kind of detectable wake? I am imagining something slamming into every particle along a straight line between stars. It ought to be like a jet contrail. Why don’t we detect these? Are we looking? (I did check once and there are some papers on this, but I don’t know the details). If a Buzzard ramjet actually worked, it would even be more noticeable I think.
PaulBC, cf. https://en.wikipedia.org/wiki/Starwisp
(Also, space is big. Really big)
Re cephalopods and fire. They could make use of extreme heat sources in t heir environment, such as thermal vents and lava. Perhaps even chemical reactions that produce heat without fire.
Heck, even non-intelligent life can cause the climate to shift and end up being more-or-less extinct as a result. Look at the stromatolites: millions of years of quietly photosynthesizing, only to change the atmosphere enough to let predators evolve that nearly wiped them out.
I assume that they are calling it the Silurian hypothesis in homage to the Silurians of Dr. Who.
I guess if the author had been a “Land of the Lost” fan it would be the Altrusian hypothesis.
I know that recent human activity has caused worldwide trace levels of elemental lead (Pb) contamination everywhere. On every thing. Across the entire surface of the planet. (Thanks leaded gasoline! /s) I wonder if that might be the most easily findable and recognizable leftover of our civilization after 100 millions of geological time. “Hey. We found a layer in the geologic record that corresponds to a mass extinction event, but it also contains trace levels of lead.”
Has anyone gone looking into the existing geologic column to see if they can find trace levels of lead? My understanding is that people have looked at certain indicators for circa 300 years ago, antarctic ice cores and deep ocean samples, and they found much reduced lead contamination compared to present day.
Does anyone seriously believe a technologically advanced species could go extinct while tons and tons of other macroscopic species around them don’t go extinct? Has anyone ever proposed any credible way that could actually happen?
Honestly seems like the kind of fantastic nonsense you’d see in a “Spirit Science” video.
But at least they’d have the good sense to propose a Noah’s Ark type thing to save all the species, and just say that we’re the descendants of that ancient Atlantis civilization…
Brian, well, there have been a bunch of extinction events.
That is not dead which can eternal lie.
Ia! Cthulhu ftaghn!
Gerrard @34:
I initially read ‘layer’ as ‘lawyer’. Works either way.
Brian Pansky @35:
Human specific bioweapons?
Doesn’t that basically describe the Great Oxidation Event?
Seems like the fact that we were finding mineral deposits and energy sources (e.g. oil) in easy-to-reach places means there hasn’t been a past intelligent civilization with the capability of accessing them.
While we have huge samples of species on Earth and its fossil record, we only have one sample of its evolutionary history, so it’s very hard to say whether technological intelligence is extremely likely or extremely unlikely.
Beware anthropic/observer bias. Any creature that first evolves complex abstract thought is likely to wonder why it was the first. And while it took over 4 Gy, you could use the same argument for the first flying animal (an insect >400 My ago) to say that flight was a complete fluke unlikely to be repeated. The oldest eye in the fossil record is around 500 My old. And while it sounds impressive that it’s taken all of 4+ billion years for human intelligence to appear, it took 3.5 Gy for eyes and 3.6 Gy for wings.
In short, we don’t really understand all the contingencies and restrictions in our evolutionary history.
As several commenters up above have stated, I think it’s very unlikely that an advanced technological species existed prior to humans. If they did, I feel it is very likely they would have exhausted the easily accessed coal, petroleum, and metal ore deposits, leaving us with nothing to give our burgeoning tech boost to the next level.
If we were merely concerned with tool-using intelligent species, I imagine that would still be notable in the fossil record, (again, as others above have stated…) through stone tools, ceramic/pottery remains, rapid spread/expansion of useful plant/animal/etc. species, disturbance of sedimentary layers, char and other remnants of fire, etc.
As to the Fermi Paradox, I’m leaning towards the idea that any species/civilization that lends to rapid technological development, likely does so out of competition/aggression, and either exhausts it’s resources, or kills itself off through some mechanism like nuclear war, global warming, biowarfare, etc. Those that aren’t rapid, maybe don’t develop tech quickly enough to protect themselves from the more mundane, periodic extinction events?
In some ways, I find this topic really interesting to think about, but then again, considering our current political hellscape, it can be pretty depressing and disappointing…
Madame Vastra would like to have some words with you
Consider the scenario from David Brin’s Uplift series: alien life has inhabited Earth in the distant past but, like good environmentalists, they took what they could and buried the rest in an oceanic trench, there to be subducted deep into the mantle.
This was discussed in the first of the Science of Discworld books. Geological turnover has been so thorough, that it’d be hard to tell if some dinosaurs had a civilisation.
Of course, if it lasted until the Chixaulub impact, we might be lucky that some of their artefacts made it to the Moon along with their corpses.
What about ants and termites? Even beavers (dams) and spiders (isn’t the web a form of technology?). If you mean the kind of reliance on technology we have, only animals with similar behavioral complexity and flexibility to our own could develop it. That seems to be dependent on having a large brain (relative to other animals of the same size). And as far as that goes, if we look at the past half a gigayear, hasn’t the upper limit of brain size (in that relative sense) tended generally upwards in the way you might expect of an asymmetric branching random walk? It appears to me that once animals appeared, (or maybe once bilaterians did), the evolution of a species with sufficient behavioral complexity and flexibility to develop extreme dependence on technolgy was highly likely. What evidence we have suggests that the barriers to that evolution lie between the origin of life, and the “Cambrian explosion”. One is the necessity and difficulty of the symbiosis that produced the eukaryotic cell (see Nick Lane’s The Vital Question), which seems to have been a unique event that took maybe two gigayears to happen, but there may well be one or more other barriers, as there was still around a gigayear and a half until bilaterians evolved.
I agree with the earlier comments which suggest that an earlier civilization with technology comparable to our own would probably leave long-term traces simply by depleting the fossil fuel deposits (leaving a lot less for us), and redistributing deposits of metals plus spreading other species around the planet in ways that would be virtually impossible by other means.
Isn’t there a theory that the planet froze over almost totally around a billion years ago because all of the photosynthetic bacteria depleted the carbon dioxide in the atmosphere and cooled the planet too much? I might be wrong about that, but it would be an example of organisms without any brains at all almost making the planet uninhabitable.
I tend to agree that intelligent life is relatively rare in the universe, though I very much doubt that we are totally alone. However, it is also possible that intelligent life develops fairly often but either tends to destroy itself quickly through war or environmental disaster, or lasts longer but is non-technological, either because of physical limitations or different psychology. Non-technology using intelligent life could only be detected by actually going to the places where it lives.
I have no idea if life is rare or common in the universe, and I don’t think we have enough information at this point. Fermi’s paradox is an interesting thought experiment, but it presupposes a lot about the motivations of intelligent life. Is there some reason to think you’d definitely go expanding into other stars? The resources in our own solar system dwarf those of our planet, and there is no reason to believe we’d retain our biological form into the far future rather than miniaturize in some way (whether “uploading” into a digital computer would really work or some other miniaturized intelligence would be work). There’s also no reason to believe we’d be likely to broadcast our existence using communication accessible to some 21st century human civilization in another star system.
I think the question of how frequently does life emerge from non-living matter is at least as interesting as how frequently does a technological species emerge in a living ecosystem. But neither seems inevitable even starting with suitable conditions. We need evidence that we don’t have to say if it’s likely.
It seems nearly impossible that we are “alone in the universe”. Why would the universe produce exactly one intelligence species? But I don’t see why we couldn’t be alone in our galaxy. Maybe 9 out of 10 galaxies have no life at all despite having planets that look like they could have produced life. At this point, it really is just a matter of probabilities that we don’t have. I think that would be disappointing, but I don’t see how you would rule it out (even accepting Fermi’s paradox).
The mildly deranged penguin points out that except for that drunken night out with Plato, Atlantis remains hidden…
@#49
You’re quite correct, we don’t really have enough information to do more than guess the abundance or lack thereof of life beyond earth, all we can do is speculate. The one piece of the puzzle we have found is that planets of many different sizes around other stars appear to be very common – 25 years ago, we didn’t even know if many stars had any planets at all.
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blockquote>Is there some reason to think you’d definitely go expanding into other stars? – PaulBC@49,/blockquote>
No, but if technological cultures are common, any explanation of why none have apparently reached here has to apply to all of them. IOW, there has to be a reason you’d definitely not go for interstellar expansion.
KG@52
If I understand Fermi’s paradox correctly, it kind of assumes that the norm would be civilizations that send out some kind of self-replicating hardware, expanding in a sphere from their origin at some fraction of lightspeed. Even if it were only 1% lightspeed, we’d notice.
(a) Let’s assume that some civilization likes that idea. (b) Many others may just find themselves occupied with their own star system (after all, high technology should not have nearly the bulk needs for matter and energy we do). I think that could be very common. It’s unclear what you need those faraway stars for and you’re pretty far removed from simple instincts of self-propagation.
(c) Some other civilization may really hate the idea of (a) and may see it as their mission to prevent it. So they could be sending out probes in somewhat less detectable numbers and weeding out the ones who attempt massive expansion.
Which civilizations are more common (a) or (c)? I think (a) presupposes that an advanced civilization possesses the propagation drive of a bacteria culture. Even if a few do, the question is whether they’d get away with it. Why shouldn’t (c) be a lot more common? It seems more like an advanced civilization to anticipate and fix a galactic mess than to create one.
Anyway, none of this is new (I think the Wikipedia page on Fermi’s paradox has some variation of the above argument). While the scenario is admittedly complicated, the point is that the existence of a single civilization hellbent on galactic expansion is not enough to mean they should be here already.
PaulBC, doesn’t matter one bit, because it only takes one instance for the hegemonising swarm to do its thing.
—
I do notice how PZ’s SATI has veered into SETI.
@54 Well, it only takes one in a favorable environment, but my point was that this might be exactly the kind of stunt that gets you quarantined by the 10x more common civilizations that don’t like it. For whatever reason, we don’t seem to be a the verge of being gobbled up by interstellar von Neumann replicators. The question is why and whether it should even be surprising.
Anyway, I find SETI much more plausible than SATI. Hence my topic drift.
Ahem, PaulBC, one can only quarantine stuff within one’s domain of influence — so you’re postulating an extant hegemony to explain why there can’t be a hegemony (different kinds, but still).
@56 True, I guess I am postulating a stealth hegemony. The killer probes should be able to replicate just as well as the uncontrolled expansion probes, but they only do it when they need to. (Anyway, not a new idea.) Lots of potential resolutions. https://en.wikipedia.org/wiki/Fermi_paradox#Hypothetical_explanations_for_the_paradox
I’m intellectually comfortable with the idea that there is an average of less than 1 space-faring society per galaxy. I can’t see why that might not be true given no other knowledge of the probabilities involved. However, it’s disappointing, and the idea that they’ve visited this solar system but didn’t make a big commotion about it seems more interesting.
Or maybe they’ve had a look at us and decided to steer clear — an option I can fully understand.
PaulBC,
I suppose your “stealth hegemony” is not impossible, but it’s a weirdly baroque hypothesis about the motivations of civilizations for the existence of which we have no evidence whatever.
KG@59
Well, I don’t really believe it, but there does need to be some resolution to the Fermi Paradox. As I said, it might be that most galaxies have no “intelligent” (or technological) life at all and we’re alone in this one.
Given that self-replicating probes would eventually fill the galaxy, it is reasonable to wonder why we don’t see any evidence of them assuming life is more prevalent. But without speculating specifically on what’s going on, it’s possible there is a more complex ecosystem of intelligent life than merely any civilization that wants to expand is free to do so. There is simply no way of knowing. But the Fermi Paradox itself is just an interesting thought experiment, not really a blocker for the existence of other intelligence life in the galaxy.
PaulBC:
My answer: what’s the point?
As you yourself noted: “after all, high technology should not have nearly the bulk needs for matter and energy we do”, and an entire solar system is more than plenty of condensed matter and energy.
(Also, to get fanciful, a decent Matrioshka Brain would be basically undetectable, other than as a smallish gravitational anomaly)
In terms of being fanciful, how about a civilisation that used biological forms to undertake the tasks, and built recyclable and renewable structures from the very start, avoiding environmental and ecological degradation thereby?
(Tricky bit: then they… um, built a bioship and set off, leaving Earth primed for primates?)
[not quite too late for us to change to sustainable subsistence, but I can’t see that happening, because our know-how is almost there, and there is still some buffer. But.
Alas]
PaulBC #57, 60:
You should think temporally as well as spatially, since there is spacetime not just space. It’s possible that we happen to be “alone” (or practically so) in the Milky Way now. What little evidence we do have isn’t very compelling, and I simply have no idea. All I’ve got is “it’s possible.” Anyway, there’s an enormous amount of time to talk about, particularly in the future. So, it’s kind of senseless to ask about the average number in a unit of volume (around a galaxy) or about the probability of finding one there, because you need to ask about the time as well.
Suppose the question were something like the chances that our solar system is a protoplanetary disk, or that the Sun is a red giant or a white dwarf. Of course, none of those correctly describe the current situation. However, the white dwarf stage is almost the entire history for a star like ours. From wikipedia, with references to a Fred Adams paper you can find on arxiv:
It should go without saying that all of those are very long times, and 10^200 years is absurdly, ridiculously long. And it’s worth writing out the very lowest estimate, 10^30 years, to drive the point home: 1,000,000,000,000,000,000,000,000,000,000 years. Or you could say that’s one billion squared times one trillion years (since the exponent is 30=9+9+12), if that helps you wrap your head around it.
The 4.5 billion years we’ve counted so far, for the age of our Sun and its system (i.e. what most people fuss over), is basically nothing compared to that: it’s only 4.5×10^-21 or 0.0000000000000000000045 of the whole thing.
So “right now” — or the last billion years or the next billion years or whatever “sorta big” number you want — may not really be a good, representative time slice. If you picked, say, a random 10 billion year period from that huge 10^30 year chunk of time (again, the lowest estimate), the probability is very close to zero that you picked the first 10 (or 13.8) billion years since the big bang or the next 10 billion years after that or the next after that….
So you could ask why this roughly 10 billion year time period was chosen (or even a much shorter time, as some people have done), rather than some other 10 billion year period. Why did we decide to draw that specific one out of the hat (treating it as if it were very “special”), rather than any one of the 1,000,000,000,000,000,000,000 other 10 billion year periods that could have been chosen?
We don’t really know when no life at all will be around anymore (never mind “intelligence,” whatever that is). There may be some places which are at least “habitable” in the very distant future – proton decay would certainly put a damper on things (if nothing else does first) but that still allows for an absolutely enormous amount of time.
More from #60:
Well, no, it’s not a thought experiment. Fermi just pointed out that there’s a paradoxical relationship between multiple purported facts, all of which seem to be correct. It isn’t really a contradiction, but it is enough to raise suspicion that we’re missing something or that we’re misinterpreting it.
Self replicating probes might not be possible whether there’s other technological civilisations or not.
timgueguen@65
I suppose anything might not be possible if it hasn’t been done, but it’s clear that self-replicating biological systems exist. The basic principle of self-replication was also worked out abstractly by von Neuman in a cellular automata framework. It’s not quite as obvious as it sounds. You need a method to replicate the instructions that is simpler than the way you replicate the replicator itself. People understand this pretty well now, but before this observation, it seemed there might be an infinite regression (i.e. another replicator for the replicator model, and a model for that one, ad infinitum). William Poundstone’s The Recursive Universe provides a readable explanation of this point.
Biology uses more or less this approach; DNA replication is simpler than the development process that produces an organism capable of reproduction guided by DNA.
The open question is whether an autonomous system could be made robust enough to replicate itself from materials available around a star. That is an engineering question. The “probe” does not need to be a small, contained machine. For example, it could require the equivalent of an automated factory as a bootstrap, provided that factory could build all the space mining equipment, etc. to build another factory. I don’t think we’re far from self-replication in terms of terrestrial manufacture. We have semi-reliable self-driving vehicles and automated factories. How much do we need to have automatic mining operations and a fully automated supply chain? (There is no economic incentive when people are available to carry out these tasks, but there is no obvious missing piece.)
consciousness razor@64 That sounds like a variation of “we’re the first”, though I apologize in advance for mischaracterizing it. If it is possible for there to be one (potentially) space-faring civilization at this early stage, then why not more of them? There may be good reasons why. I personally lean to one of: “There are but they’re really far away, like in another galaxy.” or “They’re in this galaxy right now, but Fermi’s view that they should be detectable is flawed in some way.”
And, yes, it could be that there are no “space-faring” civilizations at all because they always self-destruct first. I doubt the answer is that absolutely nobody out there with the technology is remotely interested in expanding in some form, just not explosively.
1) Search for knowledge.
2) Search for life elsewhere.
3) Search for possible rivals, in order to exterminate them.
4) Game of galactic billiards.
5) Showing off to the local gods.
5) etc.
The point is, if: “There are lots of cultures capable of sending out self-replicating probes, but no-one bothers” is to be an adequate explanation, it has to apply to every culture – in other words, they all have to have the same lack of motivation for doing so as John Morales.
The Fermi paradox is predicated on them being possible. Why would they not be?
PaulBC@60,
I don’t think we’re far apart in our views. I think the next most plausible answer to “There has never been a technological culture in our galaxy capable of sending out self-replicating probes”, is something like: “We’re on a reservation”. In which case, we’re probably being studied, from some way off.
Since the usual estimates for the time needed for self-replicating probes to fill the galaxy is on the order of a few million years, it’s quite likely that the first culture to send them out would be alone in that capability, and in a position, if it wanted, to prevent any others doing so.
KG@68 I’m not sure the reservation idea is less baroque than a stealth hegemony (or if you could implement the former without the latter).
If we assume it’s highly probable that somebody will succeed in launching self-replicating probes that fill the galaxy over a few million years (a very short time), then maybe that’s the disaster that precludes the development of other natural intelligent life, so it turns out that we have lots of neighbors in the galaxy either not leaving their system or behaving themselves, and the knucklehead who’s going to screw it up hasn’t appeared yet.
Of course (and I’m not the first to observe, but I often forget) my optimistic scenario fails some form of the anthropic principle. If the future means converting the solar system into a utopia of quadrillions or more highly efficient super-intelligent sentient beings, what are the odds that I would have shown up right now when there are just a few billion squishy bioforms?
Sometimes I think the idea that I’m living in a simulation works better than any of the above.
PaulBC:
What I said was basically “I have no idea” and “if you’re going to say anything interesting about it, time is a relevant and important parameter.” Yes, that is mischaracterizing it.
Let me ask you: we’re “potentially space-faring” and perhaps never “actually space-faring,” in the grandiose sense of space-faring that means something more than a few trips around our own solar system. So how would you know that there are no others like us right now? What are the signs of that kind of “potential” supposed to be?
If an alien species looked at Earth, the real Earth we inhabit, they’d see something rather unimpressive compared to the things that many sci-fi writers have written about in fiction. (But it’s our home, and I like it.) The point is that we don’t live in any of those fictional worlds. And I don’t know if it will ever be the case that humans make a noticeable dent on a galactic level – that is, sufficient to produce overwhelming evidence of our existence which aliens at our current technological level could easily observe, if any are having arguments like this among themselves. If they have imaginative fiction traditions like we do, they may have their own versions of people who mistake this one for the Star Trek universe; but they would be mistaken as well, because this isn’t the Star Trek universe.
KG:
I’ll assume that estimate is correct. (However, it is very speculative.) By that, don’t you mean that “a few million years” is the time will take us to fill the galaxy, starting now? (On this scale, “now” is essentially the same time as when Von Neumann first brought up the idea several decades ago, if you’d rather pick that starting date.)
Earth has been around for 4.5 billion years and so forth, but we shouldn’t start the clock on our self-replicating probes filling the galaxy until somebody here actually starts making them and setting them loose. Right? If you want an answer to why it seems that nobody else is doing that, maybe it’s reasonable that projects lasting millions of years at a time aren’t typically done by moderately-intelligent technological species like us.
We have a lot of trouble doing anything constructive and significant which is on the scale of a couple decades. We don’t know if climate change or WWIII or a catastrophic meteor impact or whatever will destroy us first. And we’re a species that hasn’t left its home planet’s orbit, which can only imagine generations-long trips to the next nearest star systems. (By the way, how long is a lifetime for a typical alien? We have no clue.)
Just getting by in the world and dealing with more immediate concerns isn’t so easy, even in a “nice” place like Earth. If you proposed some esoteric project that will come to fruition in a “mere” 1000 years, most people would simply dismiss it. Proposing something a thousand times longer than that is just asking for ridicule. Even if it sounds like it may be interesting or useful to somebody way down the line — terraforming Mars, moving an asteroid/comet into a different orbit so it won’t collide with Earth in 1000 years, sending people or probes or what have you out of the solar system, etc. — I don’t see people actually doing anything at that scale right now. It’s possible we may never do things like that.
So, if you want a reason why nobody else is doing it (as far as we can tell), well then, we evidently have a bunch of reasons for ourselves that come in a bunch of different flavors: economic, political, biological, psychological, and so on. You could speculate that in a million years, all sorts of things like that won’t be enough to stop us, only to slow us down. Maybe that prediction will turn out to be a good one, but it is certainly not a known fact that we can actually use right now in an argument.
I agree. Basically, if you go beyond “There has never been a technological culture in our galaxy capable of sending out self-replicating probes”, you’re necessarily into baroque speculation about the motivations of alien cultures.
consciousness razor@70,
You seem to me to be suffering from a severe lack of imagination. One thing we can be pretty certain about is that the world in (say) a thousand or ten thousand years will be radically different from the world now, in terms of technological capability. By far the most likely difference is that there won’t be a technological culture at all, at least beyond foraging, small-scale farming and the necessary associated technologies, because the environmental crisis andor nuclear war will have overwhelmed us. So one possible reason why the galaxy doesn’t appear to be full of self-replicating probes is that all cultures that might be capable of launching them discover capitalism and promptly destroy themselves. But if we avoid that, it seems very likely our descendants will have technological capabilities far beyond ours. It’s also possible they’ll have settled into a largely static technology, but that again would be radically different from what we have now. So in any of these three cases, the “reasons for ourselves” you wave your hands about are simply irrelevant: in two cases because the technical capability to launch such probes would not exist, in the third, because the economic, political, biological, psychological and so on reasons not to launch them would, if they exist at all, be very different.
“We” in terms of biological members of the species have not. “We” in terms of probes most certainly have, and there is no necessity at all to assume that self-replicating interstellar probes would include members of a naturally-evolved species, so the lieftime of a typical alien (if you mean an individual member of such a species) is completely irrelevant. People (some people at least) do plan for goals that they know will not be reached in their lifetimes, and care about what may happen even in the distant future. Maybe you don’t; I do, and I’m far from alone in that.
The relevant questions in regard to self-replicating interstellar probes are:
1) Are they technically possible?
2) Is there any generally applicable reason why no culture capable of launching them would not do so.
If the answers are respectively “Yes” and “No” (even qualified with “As far as we can see”), then the apparent absence of such probes requires some other explanation. You can of course simply shrug the question off, because of the limits on our knowledge, but in fact, you don’t – you feel impelled to argue it. Why?
Sorry – there’s a spurious “not” near the end of point (2) in #71.
My imagination is if anything overactive. However, I do think it’s important to acknowledge the difference between facts that we do actually know and statements about “possible” or “likely” things that we don’t know are true. On other blogs, I may not have very high expectations, but I don’t think this is generally asking for too much on FTB.
The relevant point being that these cases wouldn’t help your argument. I appreciate the honesty, but I will disregard them.
Perhaps they would be, but you haven’t actually explained how “technological capabilities far beyond ours” has any relevance to whether these descendants would have different perspectives/motivations than ours with regard to self-replicating probes being launched all over the galaxy.
There are many things that we could do right now, but we simply don’t have very good reasons to do them. If you told me there’s some new thing that could now be done, due to some kind of increased technological capabilities (I’ll leave it entirely open what that might be), there would still be perfectly coherent and important questions to ask about whether we should do this new thing, whether we want to, whether it would be worth it, and so forth.
I’ve argued several times with people here about colonizing Mars. Even though genuine colonizing would I think probably end in disaster, it is technologically feasible for people to start working on the first attempts at that now (or relatively soon), whereas it certainly wasn’t a century or more ago. But the question being asked is whether we should do that, not whether we simply can do that. Has that technological change entailed that anything relevant has changed for us economically, politically, biologically, psychologically, etc.? No, of course it hasn’t.
You’ve only offered some hand-waving to support the idea that it would be any different in the case of self-replicating probes. Not evidence for the conclusion, not a coherent argument which implies it…. I don’t want to dismiss this out of hand, and if I did have something substantial to work with, then I’d think your arguments are at least getting somewhere. But I guess that’s where things stand at the moment.
Well, I do personally care about some such things, but of course that doesn’t mean galactic exploration should make it onto my list of “things in the distant future to care about.” I do enjoy science fiction and so forth, but what I really care most about in regard to the future is not making some kind of mark on the galaxy, just that future people have decent lives. If we don’t make a gigantic mess all over the place like the British fucking empire, then I’m certainly comfortable with that. Indeed, I would prefer it if we didn’t do something like that, and sending robots all over the galaxy to do who-knows-what is just not my idea of the best kind of future. (Is it anybody’s? Really?) I think I’d have to be convinced first that it isn’t a completely horrible idea on the face of it, and only then work my way very, very slowly toward real enthusiasm and support. Did you not have to go through a process like that when you first heard of the idea?
Anyway, maybe I’m more cynical than you about how thoroughly dysfunctional our society is in terms of solving big, serious long-term problems. Climate change and other environmental issues are obvious, but really just the tip of the iceberg (no pun intended).
If it were just up to you or people like you, then sure, you may decide self-replicating probes are a good idea. I honestly don’t get what the tangible benefit of them is supposed to be, but whatever…. The issue is that many don’t think like you do about them. You may not be alone, exactly, by my impression is that the serious ultra-long-term planners among us are a tiny minority, who could not plausibly pull it off by themselves. Even if you had someone like Elon Musk putting everything he had into it, it still wouldn’t happen.
Will some technological change or other significantly alter that set of facts someday? (I mean about most people not thinking very far ahead, and all the things which cause that, including perhaps personality differences.) You can hope for the best, if you like, but I really don’t see why I should expect it as a likely outcome, especially not one that’s due to increased technological capabilities. Maybe we just have very different priors.
I’m not clear about what you mean by “some other explanation.” What’s supposed to be the prime explanation that you’re assuming here? That there aren’t any alien species “like us” in the galaxy right now? Or if not the whole thing, then some part of it which is fairly close to us (both spatially and temporally)?
I think it’s more interesting to discuss things with other people. You probably could’ve guessed “human being occasionally enjoys social interaction,” but I hope you find that explanation satisfactory.
Not today perhaps, but this is where KG’s point about technological capabilities comes into play, I think.
If I’m reading correctly, your argument is 1) that most (human) people don’t think launching such probes would be very interesting, a good idea, or both; 2) that the relatively few individuals or groups within (human) society who do think it would be a good idea would be unable to pull it off; and then (implicitly) 3) that all potential non-human mentalities and societies would share these traits and limitations, to a sufficient degree that not a single self-replicator or colony effort has ever, anywhere been launched*.
The thing about the Fermi Paradox is that, even if 1 and 2 are true, this line of argument still founders on 3. Like a lot of ‘answers’ to the paradox, it’s possible, but entirely speculative.
And then, even within human civilization, especially over a sufficient scope, points 1 and 2 are dubious.
Point 2 is essentially moot. We’re talking about hypothetical self-replicating probes here. If self-replicating space-probe technology is possible at all, and we survive long enough to invent it, then the kind of resource constraints you’re relying on to hold back small groups very likely dissolves. In a future where such tech exists, a group wouldn’t need the political consensus to mobilize the whole solar system for the project, just enough crowdfunded pennies to launch one probe.
Even without self-replication, both points seem DOA. We’ve already launched at least a couple of interstellar probes, and small groups are talking about launching more concerted multi-decade/century ‘star wisp’-type projects, potentially even with just private funding**. A mix of curiosity and doing the thing to see if it can be done seems to be a good enough reason for enough people.
I think maybe you’re gesturing at some kind of argument that any civilization with the wisdom to reach the point where they can unleash a fleet of self-replicating robots on the galaxy will also have the wisdom to refrain. Which is, again like most ‘answers’, possible, but not necessarily a given. From where I sit, it looks like we could very well manage to scrape through our current troubles and get within a hair’s-breadth of the former without making much progress on the latter. I certainly wouldn’t want to place any bets, let alone hypothesize that as some kind of iron law of galactic civilization.
-—
* Or at least anywhere and anywhen within a 4 dimensional bubble several million years across.
** Even without self-replicating technology, launching a few (thousand) tiny interstellar probes is probably far, far more tractable and affordable than building settlements — stable or otherwise — on Mars. It’s unclear why you countenance the latter as having at least inklings of feasibility, but not the former.
There isn’t one.
That’s why it’s a paradox. Something doesn’t add up, but there’s really no way to say what yet. All we can do is conjecture, and all of those conjectures fall short to various degrees, including, I’m sure, your or my favorite ones, whatever they are.
jack lecou:
This sounds circular to me. I don’t think you should just assume “such tech exists” and with that conclude that it exists.
Also, it isn’t just a matter of money or technology (nor even social/political acceptance, although that may be an issue too). The thing has to be designed to spread copies of itself all over the galaxy. Again, there’s no obvious reason why anybody would want to make that, but I’ll leave that aside for now. Because the point here is that this doesn’t seem like the sort of thing that could just fall into your lap one day, like the invention of sliced bread or the wheel, so now somebody merely needs to scrape together the bits and pieces necessary to actually make one.
You have to say to yourself, “hmm, I have no clue why, but I have come to the conclusion that I want an AI that can successfully travel extremely large distances for extremely long periods of time to other star systems, is able to detect/intercept/extract/use all the materials needed to make copies of itself (which had better be easy for it to find/obtain). And I want this AI to have that as its personal mission, which it will it dutifully instill in its descendants, which will fill the galaxy.” And then you have to spend what’s probably an inordinate amount of time figuring out how to design that (perhaps after getting permission to do so), then getting whatever materials are needed to make it (if you have permission), then making it (if you have permission), so that all of this is what will actually happen.
And then of course the final step: profit! Or no profit, just because! Or something like that. But the whole story needs to not sound like an implausible and pointless conspiracy theory, one that Trump would dream up with if he were too intelligent for his own good rather too stupid for his own good. At least try to give it some naturalistic flavor, so that people will be sucked into the story and not think much about the plot holes.
(Also, some millions of years later, some people on Earth have to say how surprised they are that we don’t see such things everywhere, which they take to be strong evidence that there are no other intelligent lifeforms in the entire galaxy, or rather not ones existing millions of years ago. That’s when this conversation right here is supposed to be happening.)
But I suppose my problem at the moment is that you just leap to that point in time, while giving no explanation of how it transpired, when nearly all of this has already happened and someone merely needs to do a little crowdfunding of some pennies. Do you get why I’m not very happy with just assuming that someone already reached that point and now has to do basically nothing (or whatever it may be, it’s trivial)?
But since they’re not self-replicators (or aren’t directly aimed at every alien’s doorstep with a big “Greetings From Earth” sign attached), their apparent absence will not count as evidence. By hypothesis, they’re not conspicuous or ubiquitous in the way that the self-replicators are supposed to be, so for that very reason they don’t count.
Whether you could consider it wisdom or just having other interests, that’s not too far off. But look, if I’m supposed to find it unlikely/astonishing/surprising/etc. that so far not even a single civilization in the galaxy (of which we have no actual count), and that’s why we don’t see this kind of evidence for them, then what I’m really saying is that I don’t think that sounds unlikely. It sounds like a lot of trouble for nothing.
In actual fact, we haven’t done it on a whim, and for all we know, we may never do it on a whim. It’s not in actual fact a trivial problem to make such a thing…. If you can’t account for the fact that nobody today has any idea of how to do it, and the reason you can’t is because you regard it as either a trivial matter or as something which is just inevitable due to the “march of progress,” then the way I see it is that you can’t account for all of the facts.
I didn’t claim and don’t have to claim that what I just said is “necessarily true” or anything of the sort, so I don’t get the point of your last statement.
I have no idea what such a thing would even be, and I don’t think I need it to say any of the things I’ve been saying.
jack lecou @75:
I’m not so sure. What species with the appropriate technology wouldn’t ask “what could possibly go wrong with unleashing self-replicating probes on the galaxy?” and come up with some pretty scary answers.
Sorry, I dropped a few words:
“if I’m supposed to find it unlikely/astonishing/surprising/etc. that so far not even a single civilization in the galaxy (of which we have no actual count) has done this, and that’s why [blah blah blah]”
No, it’s just logic. I wrote those ‘ifs’ in there for a reason. There are two possibilities: either ‘such tech’ is possible within the physical laws of our universe, or it’s not. If it’s not, than that’s the answer, and we could stop there. But if it is possible, then you proceed: What are the chances that some civilization will discover it? What are the chances that a civilization that discovers it will use it?
It is conceivable that sending anything other than a few wisps of cosmic-ray battered space garbage to another star system is either just flatly impossible, or would require such a cosmic scale of effort that it is impractical. I don’t think we have any particular reason to think that’s a hard stop yet, though, nor does that seem to be your argument. (And, after all, if we’re talking about the physical possibility of compact, self-repairing, self-replicating mechanisms, well, we obviously already know those can exist at least in some form. )
So then, we move on. Assuming space-based self-replicators are possible, how likely is it that a technological civilization will figure out how to build them and harness the technology? We can look around and observe that human physical science, at least, is already rapidly galloping down the sorts of paths — miniaturization, automation, space travel — that would lead to it. If it is indeed possible and if (that word again) our civilization doesn’t collapse or die out, it seems like we ourselves would be able to contemplate building such things within a couple of thousand years, on the outside.
And if we never go down exactly that path for some reason, we still have to reckon with however many other hypothetical civilizations we’re talking about. All it takes is one.
Seriously?
Universal paperclip concerns aside, the utility of the technology seems pretty inarguable, no? If you could operate them safely, why wouldn’t you want automated, self-replicating factories on Earth producing useful stuff, for example? And for space exploration, it’s almost a no brainer. If you’re going to build a base on Mars, or, say, a giant telescope/particle accelerator/whatever in the outer solar system, why would you ship all the supplies from Earth if you could just send a single factory probe out that could bootstrap the whole thing on its own from local and/or comet and asteroid material? If such a thing is possible, it’s the logical endpoint of in-situ resource utilization, and it’s useful out the wazoo.
From there, it’s not really that much of a leap to think you’d want to send something out to the stars. Why? Well, like I said before, if (<— see what I did there) it’s cheap and easy enough — which is to a degree implied by self-replication — then ‘just because’ might be good enough for some people.
But another good reason would be to look for life. Telescopes and spectrograms only get you so far. And there are also only so many probes you could send out just from here. The closest couple hundred stars, maybe, but what about the hundred stars beyond each of those? And the hundred beyond each of those? If you send out self-replicators, you just have to keep the receiver on and sit back and wait. In a few thousand years, the observations of distant alien pond scum or whatever are going to start pouring in. Or not – which will also tell you something.
I think it’s pretty easy to see our civilization doing that, if (ahem) we survive. But if not us, then surely someone. Again, all it takes is one.
They count for motive, which was what I brought them in for. You’ve got a two step going here: “we don’t have the technology, but if we did, nobody would want to use it”.
You can obviously have the first, for the time being, but the second is, I’m sorry, laughable. We were launching gold records at ET civilizations in the 1970s. If you’re going to convince me that people are suddenly going to stop wanting to do that if and when we ever get our hands on the technology to really scale the effort up, you’re going to have to give me a good reason. And it’s going to have to be a reason that works reliably not just for us, but for everyone else who might have been out there in the galaxy within the last few tens of millions of years.
Well, very possibly ours. That’s what I was getting at with ‘wisdom to refrain’ and iron laws and so forth.
On the one hand, yes, it’s totally true that self replication, the requisite autonomous AI, etc. are indeed potentially very scary. Even if the first few generations were guaranteed safe, there’s the slightly worrying matter of evolutionary effects kicking in, especially over the cosmic time scales they’d potentially be around for. A wise and responsible civilization might well not only balk at that, but also take effective steps to prevent any of its members from letting something like that loose.
On the other hand, I look around at our own so-called civilization and see something that is, on the scale of deep time, maybe an eye blink or less away from potentially having the physical technology for that, but probably at least an eye blink and a half from having the social and organizational wisdom to always, collectively, make the right decisions on things like that.
That is, it seems like a race between technology and wisdom, and in our little corner of the galaxy at the moment, technology seems to be in the lead. Even if it doesn’t win in the end, the timing will be awfully fine. Betting on the underdog to win with a photo finish like seems like an awfully flimsy thing from which to extrapolate that the winner is — and will always be, for any and every species — a foregone conclusion.
jack lecou @81: First, and not directed only at you; is it so difficult to include the name and comment number for a quote you’re using? It makes it much easier for people who are trying to follow the discussion.
What’s flimsy, in my view, is the notion that species for which technology always leads wisdom (i.e. like us) would be in any way be typical of civilizations which actually get to the point of being capable of interstellar flight of any kind. I seriously doubt we will even get to that point, and we’re lucky to have even made it this far.
As others have pointed out, we are one data point, and, I think, probably an anomalous one.
A common trope in sci-fi is more advanced civilizations considering us as having potential. That’s just wankery. Like talking about our “achievements” in art and science, as though they matter to anyone except a small subset of our own species. The only potential we have is to become the aliens in Independence Day.
Rob @81:
But the question isn’t what’s typical. The question is what, in the balance of probability is just barely possible, given enough chances. It’s a completely different number. Not “how likely is a typical person to get bitten by an alligator in the course of their life” but more like, “how likely are we to hear about someone — somewhere — getting bitten by an alligator at some point.”
Even if we are an extreme outlier — the would-be Florida Man of the galaxy — there’s enough slop in the numbers for there to easily have been dozens or hundreds of other Florida Mans out there making the galactic equivalent of bizarre headlines already. Yet, apparently, there aren’t.
I think what I’m trying to say here is that if you’re relying on hypothetical , universally true, socio-technological relationships down in the far pointy end of our quasi-Drake-equation terms to get the numbers down (to 1 or zero depending on how you’re counting), then you’d better make sure those laws are pinching things off pretty solidly. That they’re more or less iron laws. And then you’re in the business of purporting to be able to formulate iron laws about utterly alien cultures we’ve never observed and are poorly equipped to even theorize about. Which is silly.
The simpler solution, if you need to have one at all, is to whittle it down a little bit more first. There are still more than enough fairly unconstrained terms in the equation before you get social structures and tool using and rocket ship flying*. If there are only a handful of space faring species emerging in, say, any given 500 million year span, it’s much easier to believe that none of them ever quite got around to making a lasting mark — just for their own idiosyncratic reasons, if nothing else. If you still feel like contriving theories about things like the general relationships within galactic civilizations between technological and sociopolitical maturity**, they at least won’t need to do anywhere near as much work.
-—–
*Like maybe endosymbiotic mergers are fairly rare — it did apparently take a couple billion years of trying here on Earth before we got mitochondria — and so we mostly share a galaxy with planet after planet of exotic varieties of relatively sluggish cyanobacteria. Or maybe most big-brained species are wiser — wise enough to never metaphorically climb down out of the trees in the first place (again, suggestive data from here on Earth: cetaceans, cephalopods, crows, elephants…)
** Why should wisdom lead knowledge in the general case? What we see in the life we do observe — which has a lot of organizational variety, even if it is just one lineage — is a lot more ‘muddle on through’ than ‘wisely plan ahead’, and the evolution of our society is pretty much just a manifestation of those same dynamics. Why should ET societies be any different in even one case, let alone the ‘typical’ case?
And is there some selection for wisdom in a tool-using species based on the power of an unwise one to wipe itself out? Maybe. But by my count, there aren’t actually that many chances to do so on a global scale. Especially not pre-spaceflight. By my count, our own technology has given us a menu of only two, maybe three different options for a thorough self-immolation. The odds of making it through that many rounds of Russian roulette (how’s that for a mixed metaphor) isn’t necessarily astronomical. At which point, having muddled through that far without getting significantly wiser, I think it’s hard to argue that immolation by way self-replicating space probes couldn’t very well be the next course.
(And that’s even before you really start to mix it up. Does conflict and competition and lack of foresight drive technology to a significant degree in the first place? Would a hypothetically wiser and more peaceful species arising from a more harmonious evolutionary dynamic be more or less cognizant of the potential dangers of self-replicators or contact with other life? Etc.)
Yeesh. I mean @82. How did I get that wrong?