The Fermi Paradox is the contradiction between the very reasonable surmise that there must be other forms of technologically advanced life out there somewhere in our great galaxy and the complete lack of any evidence for it.
But not quite. This paradox assumes that a more technologically advanced society would naturally expand it's energy usage and output to the point that it could be detected by us. That is, expand it's energy output to be much more than our civilization's output since we actually couldn't detect a civilization of our own scale if it was on even the nearest star.
So the paradox is entirely speculative. Alienation civilizations might go in all sorts of ways. They might spend their resources on computation (as suggested by the article), they might consciously create low-energy-usage steady-state utopias, they might eventually destroy themselves, they might just never discover a way to attain such high energy usage, they might become so efficient they don't leak energy into space or something else we haven't thought it.
It's not that Fermi is entirely ridiculous to consider but the way is presented, a lot of people wouldn't know that the universe could full of earth-level societies and we wouldn't know and that's a bit annoying.
But that’s the thing, if our galaxy had lots of 20-21st century Earth level civilizations, we would be able to detect them with our existing SETI programmes.
Personally I like the hypothesis that states eventually all comms will be encrypted and therefore indistinguishable from white noise.
We could not detect civilizations at our level because standard transmissions decay the square of the distance and so such would be quantum noise by the time they got to the nearest start. And less than that by the time they further.
According to the SETI FAQ, it would be possible for alien civilizations to detect our higher powered radar systems with SETI setups similar to our own.
Do you dispute this claim from SETI? Can you provide a citation?
I am not at a PC right now, but I can see your point. To counter, Seti should catch anything really high powered. Whether or not a civilization can operate something at that level of power, is a thought experiment.
But, still, they sift the skies, at least we are trying right ? :D
There's around 512 G-type stars in 100 light years radius around us. That's not many.
Milky Way radius is 100 000 light years.
If our galaxy had lots of civilizations that just learned radio in last 100 years - odds are quite high that we wouldn't be able to detect them YET, even if we had the technology to do so.
Only those transmissions that were timed (travelling at the speed of light) to arrive in the small number of decades where we have been listening. Other constraints may also apply
Even Seven light years is a vast, vast distance. The limit isn't 100 light years, it's something like one or less light years.
Any ordinary radio transmission dissipates the square of the distance involved. At a certain level, transmissions become so faint they are indistinguishable from quantum noise.
You can find the math done on Quora (apologies for semi-walled-garden link). Remember, there's difference between getting a signal whose properties one knows and getting arbitrary signal - if there a strong GPS transmitter or something we knew, we could wait long enough and get micro-data. But arbitrary signal, no, information theory says no. (read all the answers together).
> But that’s the thing, if our galaxy had lots of 20-21st century Earth level civilizations, we would be able to detect them with our existing SETI programmes.
But we couldn't. In general, SETI couldn't even detect such a civilization even if it was in the star system closest to earth:
> If an extraterrestrial civilization has a SETI project similar to our own, could they detect signals from Earth?
> In general, no. Most earthly transmissions are too weak to be found by equipment similar to ours at the distance of even the nearest star. But there are some important exceptions. High-powered radars and the Arecibo broadcast of 1974 (which lasted for only three minutes) could be detected at distances of tens to hundreds of light-years with a setup similar to our best SETI experiments.
The OP is right, in order for their to be a paradox we have to assume that civilizations much more advanced than ours are using a particular type of tech (the kind we're looking for, like radio broadcasts), that their using much stronger signals that we have ever used, and that the time period they used these hypothetical super powerful radio signals happens to be at the right time for us to encounter them. IE, let's say they used them for 2,000 years before moving on to other tech, but the signals only reached earth between 1,548,000-1,546,000 BC, or 450,000-458,000 BC, etc.
People are making a set of very, very specific assumptions based on little evidence. Then they see that the evidence that is available suggests that it's unlikely that every single one of their assumptions is correct, and they respond by calling it a paradox.
OP said: 'the universe could full of earth-level societies and we wouldn't know'. It's a very extreme claim and the SETI FAQ answer directly contradicts it.
> But we couldn't. In general, SETI couldn't even detect such a civilization even if it was in the star system closest to earth.
Your quote relies on us detecting re-runs of "I Love Lzcwwdrrr", but our telescopes can reliably do spectrographic analysis of faraway stars and planets these days. We'd likely be able to detect things like unnaturally high levels of hydrocarbons in otherwise oxygen-full atmospheres, and other industrial by-products.
If Alpha Centauri had a planet with an industrial civilization, we might be able to spot city lights.
>Your quote relies on us detecting re-runs of "I Love Lzcwwdrrr", but our telescopes can reliably do spectrographic analysis of faraway stars and planets these days. We'd likely be able to detect things like unnaturally high levels of hydrocarbons in otherwise oxygen-full atmospheres, and other industrial by-products.
We don't know what "unnatural" levels of CO2 on other planets are.
> If Alpha Centauri had a planet with an industrial civilization, we might be able to spot city lights.
Hmm, it is reasonable to speculate that once our sensor levels get much more accurate we might be able to sense fuzzy, indirect evidence of earth-level societies on other star systems though aggregates like city-light and pollutants. But that is a long way away from present day detection - we're detecting planets through planet going in front of them and other indirect approaches that don't yield detailed information.
The paradox itself makes no such assumptions or speculation. It simply says that everything we know indicates that life and presumably technologically advanced life should be everywhere, yet we see it nowhere. There's an absolutely phenomenal article on the Fermi Paradox at WaitButWhy [1]. Your objections are mostly just scratching the surface of the wide array of possible explanations for it.
You are simply mistaken. The article you link to filled with speculation concerning "type II" and "type III" civilizations.
If you assume earth-level civilizations as advanced, "where is everyone?" has a simple answer - "I don't know because we couldn't see them anyway". If you assume some other civilization as advanced, you are speculating. That's what speculation means.
I would upvote you so much more if I could. So many issues I see in reasonings are a direct cause of lack of imagination. What we know is limited. Speculating is interesting. But it's critical to identify it as speculation.
Again the paradox has nothing to do with that. The paradox is simply in the discrepancy in what we see versus what our current state of knowledge leads us to expect we ought see. The article covers a wide array of possible reasons for this, including the possibility of advanced civilizations not existing which seems to be your focus.
The notion in the article is great fodder for a novel, but I think this perspective is sound. You've said almost as much, but I think there's a good argument to be made that societies which undergo an industrial revolution either collapse the ecology that supports them, or survive it by maturing and expending energy on QoL for the whole biosphere. In either case the window of time for making a cosmic racket is fairly small. It could just be that interstellar networking is generally quite rare.
Personally I think the same tendency which makes us so enterprising and leads to thinking up 'paradoxes' like this, is the same thinking that makes us not-so-certain to pass the ecological test.
The argument I've heard most is that a civilization only has a short time where it's blasting broadcasts into space willy-nilly, before improving their tech and making it more efficient, thus dramatically lowering its potential to be discovered by its stray broadcasts.
I wonder if all habitable planets with simple life would have the conditions necessary to create oil and coal. Love them or hate them, they still power most of our civilization. Imagine if we did not have a gas/coal readily available? We refined nuclear as a weapon first. The need for a nuclear bomb might not arise in a power constrained civilization and thus go much long before being discovered (if ever)
I'm sure someone has simulated that but it appears highly likely that a planet with plants (or any carbon based life) will at some point "generate" fossil fuels.
And maybe, if we hadn't found oil, we would've come up with more efficient ways to use electricity generated from renewable sources. Would've taken longer but we could've made up for that later in the process. Batteries were known at the time of the oil revolution and electricity from hydro & wind were also known.
There's plenty of hydro energy available. Not having fossil fuels would've shifted where we settle. Texas would likely be less economically successful compared to Canada which has plenty of hydro capacity and hydro reserves. Long-distance electricity transportation would've come up later making ACs less popular. In the US, that would've favoured the north heavily over the south. In Asia, Singapore would've never been as successful (they say themselves that success came with the AC). Maybe China would've become dominant much earlier.
That's a nice thought experiment. Our capability of harnessing energy from renewable sources (but not electrical energy) covers 3,000 years already: sailing ships and windmills. By the time magnetism and later electricity were discovered, we already had wind-powered propulsion, milling, and water drainage.
What made them impractical for industrial uses (the first applications for coal power were steam-powered textile mills iirc) was the same issue we have with solar and wind today: output is dependent on external factors that we can't control. Coal became valuable exactly because it was the first controllable energy source.
It's hard to imagine us making the same amount of progress without an ever-present energy source (coal caches, fuel tanks, and the electrical energy grid). And it's hard to imagine why we would construct an energy grid without a prior ever-present energy source. Looking at our current means of energy storage, it seems that only hydro-electric storage is a viable option if you discount fossil fuels.
So without fossil fuels, I think an electrical grid could have originated only in very specific locations: lots of wind power, and a natural basin to be converted into a reservoir with relative ease. We would have seen massively different industrial sprawl in such a scenario, and I wonder if such a situation would ever give rise to a truly continental electrical grid like we have now.
Apart from hydro power as a very steady energy source, we also have thousands of years of history of using another arbitrarily controllable renewable resource: wood. We even processed wood to turn it into coal. And in the absence of trees we could have been burning other plants.
Granted, the amount of wood you can extract within a decade from an area without turning it into a desert or grassland is limited, but in the last 400 years we turned our focus more and more on sustainable forestry and as a result got quite good at using wood in a renewable, carbon-neutral way.
I suspect too that our usage patterns for wood are "subsidized" by the availability of coal. There was just an article here the other day that talked about how deforestation in Ethiopia (for use as fuel) has had dramatic ecological impacts up and down the Nile.
IIRC Coal caught on in England in part because deforestation had gotten so bad that they needed another source of fuel to run industrial engines
The potential for nuclear as a power source was well known.
If you read the Farm Hall transcripts [1] there are several conversations in the vein uranium engine vs uranium bomb; they all knew a uranium engine was possible and was the original research, but the war drove them to a uranium bomb.
From section 5:
"History will record that the Americans and the English made a bomb, and that at the same time the Germans, under the HITLER regime, produced a workable engine."
Or everything they’re broadcasting is encrypted, even the metadata and framing bits. With spread-spectrum, directional and burst patterns to mitigate side channels and jamming.
So the alien communications just look like noise to us here on earth.
We’re nearing the “everything encrypted” point ourselves, and we would certainly be very careful about emissions control if we ever got ourselves out of the solar system.
Presumably any other advanced civilization would have had its own paranoid Sci-Fi literature/film/whatever, and would behave accordingly.
> With spread-spectrum, directional and burst patterns to mitigate side channels and jamming.
without regulatory constraints, our own use of radio would've required that rather quickly.
i think it's entirely possible another civilization simply never would've used radio at beyond a hobbyist level without the use of spread-spectrum heavily-coded techniques.
> Presumably any other advanced civilization would have had its own paranoid Sci-Fi literature/film/whatever
i don't think it's a given that another species would even have fiction. or paranoia.
Or they might realize the universe is just inherently a dangerous place and design their own little universe to go inhabit. Peacefully exiting the universe.
What I've always thought about is if all life eventually struggles for power and destroys itself? Imaging what would happen if the whole world just worked together!
Is this something that is in our DNA, to be on top of everyone? 1% controlling the whole world, limiting their potential... Can we someday put aside our differences and work towards the same goal? Life on earth (humans and animals) don't really work together on a global scale. Is this only because of our nature, here on earth, that we need to destroy thing to live well (coal, forests, animals as food, ...)
Maybe there there are planets that have excess minerals, resources to build starships without killing their environment, without the need of wars (for oil for example).
Haven't we just had bad luck, being evolved on a planet with limiting resources, or just bad luck that we chose to use limited resources for our civilisation, or just bad luck that we need limited resources to survive? Are there a lot of civilisations struggling with the same problems? Or maybe there are aliens that can just drink water to survive and fly to other suns with just oxygen (just to make a silly example)?
This was kind of a response to "Can a civilisation really peacefully exist without destroying itself or the rest of the universe".
On the other note, imagination is such a big advantage of humans, we can achieve so much just by using our imagination. Also the whole topic of "Are we alone and where is the rest" is so interesting!
Have you, by chance, read the "Three Body Problem" and its two sequels? I don't want to spoil anything if you haven't, but it addresses these questions and that possibility in particular.
That's how I have always viewed this. There is no reason why a civilization would blast out EM waves in a 360°*360° sphere at incredibly high energy levels indiscriminately forever and ever. Instead what we have seen right here on Earth over the last 100 years is that technological progress lets us do ever more with ever less energy.
Unless we are talking about detection from a relatively low range, a range where the square-cube law hasn't reduced the energy we would receive by too much, I would not expect us to ever receive random radio transmissions from other civilizations. Which, ultimately, turns the Fermi paradox on its head: it would be incredibly unlikely for another civilization like ours to develop at exactly the same time as us and so close to us.
The Fermi paradox isn't only talking about detecting alien civilizations via radio emissions and the like. More likely would be the detection of a civilization that is harvesting a respectable portion of their star's energy. Energy is power, and stars absolutely dwarf any other accessible source.
Once basic space construction is mastered (which we are very close to), large scale solar collection seems a likely path that many civilizations would take. A Dyson swarm would probably be the first step, which would be detectable from very large distances.
Oh, yes natural selection, that mechanism that mindlessly produced creatures adapted to the Loopdeformation (Regrow->Overpopulate->War->Regrow) and pushing for expansion of there speciality in the LD.
Totally something we should bring back. If evolution as a process could be stuck in local minima, then we would think otherwise - but that is heresy.
It's also plausible that such societies are non-physical, meaning the content of the society is less about the physical substrate and more about the properties of the system itself
One of the comments at the bottom of the post points out what I believe to be a likely scenario:
"As we develop VR tech that allows us to simulate any world we desire, recreational or purpose driven, there is less and less reason to explore the rest of the universe."
Using humanity as a example for how intelligent life advances, we can look at the developed nations. The develop nations are the ones who would create any sort of technology that would get us out of the solar system and into contact with other life. Most, if not all developed nations are built through commercialization of products, with the citizens consuming those products. Only a very, very small portion of people are working on the advanced technology to take us elsewhere. So the majority of our species are not advancing galactic technology, but they are becoming larger consumers of entertainment, at least on the scale since early civilizations. Keeping that in mind, we are also somewhat physically locked in our solar system due to the laws of physics, at least in the near term. So, to me it would seem much more likely that instead of advancing space tech to the point where we are sending robots to other planets to self-replicate and spread across the universe, that by that time we would have already perfected VR and that our entertainment-based population would be well-satisfied simply living in our perfect little VR worlds. The two scenarios aren't mutually-exclusive. We are in fact advancing VR and building rockets for Mars as I write this, but I think it's also possible that simulating our reality could replace our desire to move outward. Since the universe is seemingly too far out of reach, we will just create our own here, for cheaper, sooner.
There seems to be a force which makes humans disperse. We settle on every part of this planet even in uncomfortable regions. Some people want to settle on Mars. (Curiously, nobody wants to live on our moon?)
There also is a force which makes humans cluster. Silicon Valley is the biggest cluster of IT and VC at the moment. Accelerando (by Charles Stross) describes vividly how an advanced AI civilisation still clusters (Mainly because solar/fusion power and communication speed).
We got the answer right here. It's much more interesting and probable to meet AGI than aliens. Space travel is dangerous, but virtual space is just as interesting.
I loved the irony of the virtual citizens of a polis travelling physically to another star system and the first creatures they encounter are inside the "natural" simulation hosted by the chemical evolution of the Wang carpets.
Count Zero and Mona Lisa Overdrive by William Gibson (sequels to the more famous Neuromancer) have this idea. AIs obtain independence from humans in cyberspace (VR) and eventually make contact with AIs from elsewhere.
Disclaimer: this stuff is mostly just hinted at, while the plot is mainly about people working within this context. But so awesome. Blew my teenage mind in the late 80s.
I'm thinking in a way, those awake may be at the mercy of those who sleep. Say the sleepers could hide - they could avoid a lot of turmoil, like these bamboo species that germinate for a hundred years, thus avoiding herbivores and vermin. Sleepers also can presumably also conserve resources better while those awake may build, and loose empires in the process.
They would be betting they're able to hide themselves and their resources for all those years. It also requires faith in their own scientific discoveries (the universe will be like what they predict it to be) and much group discipline and trust. What if we could go to sleep for some 100k or 1M year to wake up in a planet that had fixed the excess CO2? Would everybody do it, no cheating? Not with current humankind. Great matter for scifi.
My thought exactly. Just run the whole thing at a very low speed. One clock tick every hundred years so to speak. This will make the whole uploaded species live in a slower lane, but subjectively for them the rest of the universe will seem to have sped up. Of course this has the disadvantage of them not being able to communicate with nervous short-loved critters like us, which also neatly explains why we don't hear or see them.
My humble impression is that each and every philosophical hypotesis we make is somewhat based on human paradygms, structures, and super-structures.
Why can’t we accept that we populated this world for the equivalent of a cosmic blink, and we are therefore unequipped to even grasp the existence of other life forms?
I am a fan of Bostrom’s conjecture about the simulation, though. 1/3 is a damn high probability.
At the same time all the examples we make to wrap our heads around these mastodontic concepts are so trivial and so inherently human, that I wonder how can we really take our own musings seriously.
We might be able to escape the boundaries of Earth’s gravity at some point, but will we ever be able to escape the boundaries of our human thought?
> each and every philosophical hypotesis we make is somewhat based on human paradygms, structures, and super-structures
Unfortunately, we can't do it any other way, by the very nature of conscious thoughts.
> Why can’t we accept that we populated this world for the equivalent of a cosmic blink, and we are therefore unequipped to even grasp the existence of other life forms?
Why should we? We might be doing a lousy job, but we're doing the best we can.
> At the same time all the examples we make to wrap our heads around these mastodontic concepts are so trivial and so inherently human, that I wonder how can we really take our own musings seriously
It's not like we know of anyone else whose musings we could take more seriously than our own. The known universe, as beautiful and awesome as it is, is also dead.
> will we ever be able to escape the boundaries of our human thought?
If we survive long enough to achieve the ability to re-engineer our minds, I hope so, yes.
> We might be doing a lousy job, but we're doing the best we can.
We've literally never done this before, so we don't even have a very good idea whether we're doing a good job or not, that's how clueless we are. Signs are pointing to us more or less killing ourselves, though.
"I am a fan of Bostrom’s conjecture about the simulation, though."
It's boring as hell, metaphysical conjecture, suitable for late night bar talk and deus-ex-machina sci fi plots. The 1/3 probability especially is total bullshit. It's fun if viewed as an art project, and as such has some entertainment value.
It does not really explain anything. Unless one enjoys figuring out with theoretical physics, which facets of our world would point out to a simulated existence, it offers nothing of value when seriousy figuring our place in the cosmos.
Well, it depends. Often people consider the simulation as the stereotype of sci-fi simulations we read or watched about. But it could be much more than just "being in a computer".
I'm reminded of the old problem of the flight of bumble bees. Someone did some calculations on bees, modeling their flight using the same properties of aerodynamics as fixed wing aircraft, and they came to the conclusion that bees couldn't fly. Of course the obvious answer was that bees simply don't fly the way that fixed wing aircraft do and we merely did not understand how they flew at the time (we do know). But imagine an alternate world, a world where bees and other flying insects did not exist, then the equivalent calculation might be taken much more seriously about the impossibility of flying insects.
Similarly, what do we know about hyper advanced technological civilizations with the capability of colonizing galaxies? Basically nothing. So any model we have of them is fundamentally invalid. Even if we pretend that layering on a bunch of "conservative assumptions" can remove that fundamental difficulty of having zero knowledge of such civilizations, it very much does not. At the end of the day this is a problem that is beyond our current understanding and we cannot make any firm statements about it one way or another.
> My humble impression is that each and every philosophical hypotesis we make is somewhat based on human paradygms, structures, and super-structures.
Exactly! Each time when I hear that scientists are looking for water because that's supposed to be a condition for life - I wonder how small imagination one needs to have to think that only "water-based" forms of life exist.
Think of it this way, it's not that these scientist think that only water-based forms of life exist, but the universe is very, very large, infinitely so. Since we have finite time to search it, where would you start looking? Would you start searching every single planet/star for some life we may not be able to recognize? Or would you take what we do know - that intelligent life can evolve from water-based planets - and at least start looking there?
If there is no loophole to the speed of light limit and the Heat Death of the Universe is not just a theory I guess most individuals in advanced civilizations will decide to end their lives in some drug (or equivalent) induced nirvana.
Besides the easy answer that we're looking in the wrong places by virtue of using current human technology, my take is that an "advanced" civilization capable of interstellar travel will have learned to be way more efficient with energy usage. They'd have to be efficient for "advanced" energy usage to be cheap enough at the scale of a civilization instead of rare and expensive moonshot projects.
So they're only undetectable as a side effect of being efficient. Not because they're hiding or have all died in a cosmic extinction.
Except that the WOW signal is fully explained now as due to a hydrogen gas halo around a solar system local source that the dish was pointed at at the time.
We couldn’t detect a remote civilization at a 21st century equivalent stage of development. But at 22nd century level, they’d be able to launch a Bracewell-von Neumann self-replicating interstellar probe... and it would take just one such event to lead to the permanent saturation of the Galaxy by its descendants. So where are they? The only really satisfactory conclusion is that we’re the first or only civilization to approach a BvN launch.
>But at 22nd century level, they’d be able to launch a Bracewell-von Neumann self-replicating interstellar probe...
That's assuming that we'll get to that level by 22nd century (or ever).
I'm not so sure inter-stellar space travel and even space probing at that scale will come to be. Or even a colony as close as Mars -- for the reasons outlined pretty well here: http://www.ecosophia.net/terror-deep-time/
> The only really satisfactory conclusion is that we’re the first or only civilization to approach a BvN launch.
Not the only one. There may well be an armada of these probes on their way, but so far away in one of the billions of galaxies that the metric expansion of space means they will never reach us even at near-lightspeed - or may reach us long after we've become extinct. Or may miss our pale blue dot entirely. It's a freaking big universe.
As others pointed out, you assume that other civilizations have similar technologies, motives, potential, political situation (or politics at all) and even material structure or needs.
It's all speculation.
We have satellites and yet know very little of what's happening in other countries. We mistake their needs and intents all the time. We are regularly surprised of what they are capable or incapable to do. And yet those are identical being living in the same spot as us.
It takes just one BvN launch in galactic history to fill the galaxy up with self-replicating probes for the rest of its history. Doing this doesn't require much more technological capability than we have now. Motivation, politics, and ethics do not matter, just capabilities --
over such a huge volume of space, across billions of years, anything that's remotely possible will take place. The galaxy is very large and very old -- yet it is not overrun by frantically reproducing robots.
- they didn't find a better solution to expand than going to other planets;
- their material structure is similar to us (they are physical, they have the same size/speed/time perception as use)
- the universe has no characteristics than we don't know about that could disallow us to perceive them (number of dimensions, or whatever)
- they emit some signals among the one we can perceive;
- they need and use energy as we do and as we understand it;
- they are not actively hiding;
- if we saw them we would realize what we saw.
It's like an ant assuming that because they can't smell pheromones from another hill, there is no life there.
Now, I'm for ocalm razor and I actually thing there is a strong probability that all those assumptions are true. But I don't know for sure that they are. They are just that: assumptions.
> The only really satisfactory conclusion is that we’re the first or only civilization to approach a BvN launch.
That's carrying a lot of assumptions. That there's not a probe lying somewhere in the solar system watching us, that aliens haven't found a better way to observe us than probes, that they even care about observing us in the first place. Take the last one for example - 400 billion stars in our galaxy alone. It's entirely possible that we're not important enough for advanced societies to care, the way you're not going to stop and mess with every random anthill you pass by.
Imagine a couple of tigers talking. "Someone says there are 9 billion humans in the world." "That makes no sense. Take the amount of good hunting habitats in the world, divide it by the amount of territory an adult male would need to call their own, and divide that by the number of humans. You would have multiple humans fighting for each chunk of territory, and marking their scent everywhere. Yet I don't smell any human urine so the question is...where is everyone?"
As an aside, why do people focus so much on self replicating probes? Assuming aliens did want to send out a probe fleet - why not simply mass produce probes in one system (or a handful of systems) and send each in turn to their destinations? Having to accelerate, decelerate, build a probe, have the new one accelerate, decelerate, build another probe, have this new one accelerate, decelerate, etc., seems like it would take a lot longer than simply sending a probe directly to its destination (no need to constantly decelerate along the way, no need to waste energy moving replication units, etc.).
The problem with self-replicating probes is they're likely to break down after so many legs. And every time they decelerate, they need to get more energy from the star system before accelerating again -- their AI might not be equipped to handle every situation they encounter, so failure to continue their mission might happen that way.
In order to replicate, a probe needs material from the star system it's visiting, stuff like iron and silicon. That process is likely to break down after so many journeys, so no more replicants. The probes would put their own AI into the child probes, including their own random defects. It would take a lot of trial and error, each trial being thousands of years, for the likely success of a single journey's replication to exceed the combined half lives of breakdowns and AI degeneration.
Something to consider is that the universe is 13-odd billion years old, and from our perspective, the edge of the observable universe is about 46 billion light years away.
At interstellar distances, it is very difficult to detect something unless it is emitting something: electromagnetic energy or gravitational waves (and those are only possible to detect when there are super-massive bodies doing something extremely energetic, like two black holes or neutron stars merging).
Earth's man-made electromagnetic radius is about 110 light years. We're pretty much invisible to any other life out there.
But what about aliens that have been around for a long time? Wouldn't we see some evidence of them?
Well, the other problem is that space itself is expanding. The observable universe is 91 billion light years in diameter, but as space expands, the farthest galaxies are receding from us at ever-increasing speeds, eventually becoming invisible to us as well.
The unimaginably vast spatial and temporal scale of the universe means that countless alien civilizations may have come and gone, along with any sign of their history if their light waves are outside of our observable universe. Or their signals arrived and ceased long before humans even existed, let alone had the technological capabilities required to receive and interpret such signals (arguably, only since the advent of digital computers).
Factor in the 100 billion (or maybe 10 times more[1]) galaxies that we can see, and the 160 billion stars (solar systems, possibly) per galaxy, and the probability that we will detect an alien civilization (or vice-versa), where we are and when we are, in a universe that is mostly empty space, before we ourselves die out, seems rather small.
And analyzing the biology history, from 4.6 billion years of Earth existence, or from 13.7 billion years of universe's, for only 60 years humanity can detect the signals from space. Every step toward that wasn't "inevitable" but improbable. There weren't multicelular life until around two billion years ago, but it took then two billion years and a lot of accident to have the communicating capable humans.
And then, how long are we to last with this capabilities? We are much less smart than most believe, especially in preserving conditions for a communicating civilisation.
This is an interesting idea but from what I know carrying computation in the space just because it's really cold might not be as good as it seems: space it's almost empty (not really a vacuum but with very few matter). This means that in space you can't really loose heat by contact but only by emitting infrared radiations. This means that although space is really cold an object put in space will take some time to cool down. Correct me if I'm wrong but given the fact above I don't see a clear advantage in using space as a heatsink.
I doubt that. Any advanced civilization that is capable of interstellar travel would use highly efficient techniques to do their thing. You may say it's the gold or platinum but we just heard of the neutron stars that collided creating a lot of those materials in the process.
Why bother using humans to extract anything when there are other, more efficient, ways of harvesting? That's just "ancient aliens" conspiracy theories if you ask me.
I think it's a bit too pretentious of us as a species to speculate about the motives and capabilities of alien civilizations who may be billions of years ahead of us. We haven't figured out dolphins, FFS! I wouldn't be surprised if in 100 years we look back at all this the same way we now think about the theory of an infinite number of turtles supporting the Earth. It's all just cutely naive speculation.
If you're not that familiar with the Fermi Paradox I highly recommend Stephen Webb's book If the Universe is Teeming With Aliens... Where Is Everybody?[0] He covers a basic intro to the problem and then goes through FIFTY proposed solutions in an accessible and entertaining manner. A lot of it explains why "obvious" solutions (including the suggestion in this article and others popping up in this thread) aren't really considered so obvious by field experts who have thought a lot about the problem.
For example, many explanations are of the type "Well, maybe the aliens are all doing X," but it requires every independent civilization to be doing that, with no exceptions, so that we haven't even detected one variant, not even one that needed to escape its star and colonize the galaxy, which many experts find unsatisfying. I found the book to be a fun and quick read that touches on a lot of scientific/comsological/biological/etc concepts.
(Looks like he has a newer editing with 75 explanations...[1] I haven't read that one.)
I see the article also mentions the simulation hypothesis. Personally, I'm intrigued by the overlap between secular simulation hypotheses and religious notions of the universe having a Creator.
If we don't even know how to create life from base elements how can we even surmise to know the probability that it will happen on it's own else where?
The fermi paradox is not really a paradox if it is based off of a probability that we don't even know. Once we know the conditions and steps it takes to form life then we can take a stab at estimating this probability.
Don't trust your intuition on this, while the universe is incredibly large, nobody knows how infinitesimally small the probability of life spontaneously arising from base elements is.... Additionally, we need to know the probability of having this life form evolve into something that can communicate across space.
There are things around you that have nearly zero probability of occurring again anywhere in the universe. Unless you have a twin, the probability of someone being born anywhere in the universe with your exact configuration of DNA is nearly zero. It is possible that the formation of intelligent life shares an equally small probability. Again, we don't know this probability until someone is able to recreate it.
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[ 3.1 ms ] story [ 199 ms ] threadBut not quite. This paradox assumes that a more technologically advanced society would naturally expand it's energy usage and output to the point that it could be detected by us. That is, expand it's energy output to be much more than our civilization's output since we actually couldn't detect a civilization of our own scale if it was on even the nearest star.
So the paradox is entirely speculative. Alienation civilizations might go in all sorts of ways. They might spend their resources on computation (as suggested by the article), they might consciously create low-energy-usage steady-state utopias, they might eventually destroy themselves, they might just never discover a way to attain such high energy usage, they might become so efficient they don't leak energy into space or something else we haven't thought it.
It's not that Fermi is entirely ridiculous to consider but the way is presented, a lot of people wouldn't know that the universe could full of earth-level societies and we wouldn't know and that's a bit annoying.
Personally I like the hypothesis that states eventually all comms will be encrypted and therefore indistinguishable from white noise.
Do you dispute this claim from SETI? Can you provide a citation?
But, still, they sift the skies, at least we are trying right ? :D
Milky Way radius is 100 000 light years.
If our galaxy had lots of civilizations that just learned radio in last 100 years - odds are quite high that we wouldn't be able to detect them YET, even if we had the technology to do so.
The OP made a rather extreme claim that 'the universe could full of earth-level societies and we wouldn't know'.
If all 512 G-type stars in 100 light years had earth-level societies, we would be able to detect their higher powered radio transmissions. Right?
Any ordinary radio transmission dissipates the square of the distance involved. At a certain level, transmissions become so faint they are indistinguishable from quantum noise.
You can find the math done on Quora (apologies for semi-walled-garden link). Remember, there's difference between getting a signal whose properties one knows and getting arbitrary signal - if there a strong GPS transmitter or something we knew, we could wait long enough and get micro-data. But arbitrary signal, no, information theory says no. (read all the answers together).
https://www.quora.com/How-far-can-radio-transmissions-from-E...
But we couldn't. In general, SETI couldn't even detect such a civilization even if it was in the star system closest to earth:
> If an extraterrestrial civilization has a SETI project similar to our own, could they detect signals from Earth?
> In general, no. Most earthly transmissions are too weak to be found by equipment similar to ours at the distance of even the nearest star. But there are some important exceptions. High-powered radars and the Arecibo broadcast of 1974 (which lasted for only three minutes) could be detected at distances of tens to hundreds of light-years with a setup similar to our best SETI experiments.
The OP is right, in order for their to be a paradox we have to assume that civilizations much more advanced than ours are using a particular type of tech (the kind we're looking for, like radio broadcasts), that their using much stronger signals that we have ever used, and that the time period they used these hypothetical super powerful radio signals happens to be at the right time for us to encounter them. IE, let's say they used them for 2,000 years before moving on to other tech, but the signals only reached earth between 1,548,000-1,546,000 BC, or 450,000-458,000 BC, etc.
People are making a set of very, very specific assumptions based on little evidence. Then they see that the evidence that is available suggests that it's unlikely that every single one of their assumptions is correct, and they respond by calling it a paradox.
[1] https://www.seti.org/faq
Your quote relies on us detecting re-runs of "I Love Lzcwwdrrr", but our telescopes can reliably do spectrographic analysis of faraway stars and planets these days. We'd likely be able to detect things like unnaturally high levels of hydrocarbons in otherwise oxygen-full atmospheres, and other industrial by-products.
If Alpha Centauri had a planet with an industrial civilization, we might be able to spot city lights.
We don't know what "unnatural" levels of CO2 on other planets are.
> If Alpha Centauri had a planet with an industrial civilization, we might be able to spot city lights.
We do not even remotely have that capability.
See: https://en.wikipedia.org/wiki/Methods_of_detecting_exoplanet...
[1] - https://waitbutwhy.com/2014/05/fermi-paradox.html
If you assume earth-level civilizations as advanced, "where is everyone?" has a simple answer - "I don't know because we couldn't see them anyway". If you assume some other civilization as advanced, you are speculating. That's what speculation means.
Personally I think the same tendency which makes us so enterprising and leads to thinking up 'paradoxes' like this, is the same thinking that makes us not-so-certain to pass the ecological test.
And maybe, if we hadn't found oil, we would've come up with more efficient ways to use electricity generated from renewable sources. Would've taken longer but we could've made up for that later in the process. Batteries were known at the time of the oil revolution and electricity from hydro & wind were also known.
What made them impractical for industrial uses (the first applications for coal power were steam-powered textile mills iirc) was the same issue we have with solar and wind today: output is dependent on external factors that we can't control. Coal became valuable exactly because it was the first controllable energy source.
It's hard to imagine us making the same amount of progress without an ever-present energy source (coal caches, fuel tanks, and the electrical energy grid). And it's hard to imagine why we would construct an energy grid without a prior ever-present energy source. Looking at our current means of energy storage, it seems that only hydro-electric storage is a viable option if you discount fossil fuels.
So without fossil fuels, I think an electrical grid could have originated only in very specific locations: lots of wind power, and a natural basin to be converted into a reservoir with relative ease. We would have seen massively different industrial sprawl in such a scenario, and I wonder if such a situation would ever give rise to a truly continental electrical grid like we have now.
Granted, the amount of wood you can extract within a decade from an area without turning it into a desert or grassland is limited, but in the last 400 years we turned our focus more and more on sustainable forestry and as a result got quite good at using wood in a renewable, carbon-neutral way.
IIRC Coal caught on in England in part because deforestation had gotten so bad that they needed another source of fuel to run industrial engines
If you read the Farm Hall transcripts [1] there are several conversations in the vein uranium engine vs uranium bomb; they all knew a uranium engine was possible and was the original research, but the war drove them to a uranium bomb.
From section 5: "History will record that the Americans and the English made a bomb, and that at the same time the Germans, under the HITLER regime, produced a workable engine."
[1] http://germanhistorydocs.ghi-dc.org/pdf/eng/English101.pdf
So the alien communications just look like noise to us here on earth.
We’re nearing the “everything encrypted” point ourselves, and we would certainly be very careful about emissions control if we ever got ourselves out of the solar system.
Presumably any other advanced civilization would have had its own paranoid Sci-Fi literature/film/whatever, and would behave accordingly.
without regulatory constraints, our own use of radio would've required that rather quickly.
i think it's entirely possible another civilization simply never would've used radio at beyond a hobbyist level without the use of spread-spectrum heavily-coded techniques.
> Presumably any other advanced civilization would have had its own paranoid Sci-Fi literature/film/whatever
i don't think it's a given that another species would even have fiction. or paranoia.
Is this something that is in our DNA, to be on top of everyone? 1% controlling the whole world, limiting their potential... Can we someday put aside our differences and work towards the same goal? Life on earth (humans and animals) don't really work together on a global scale. Is this only because of our nature, here on earth, that we need to destroy thing to live well (coal, forests, animals as food, ...)
Maybe there there are planets that have excess minerals, resources to build starships without killing their environment, without the need of wars (for oil for example).
Haven't we just had bad luck, being evolved on a planet with limiting resources, or just bad luck that we chose to use limited resources for our civilisation, or just bad luck that we need limited resources to survive? Are there a lot of civilisations struggling with the same problems? Or maybe there are aliens that can just drink water to survive and fly to other suns with just oxygen (just to make a silly example)?
This was kind of a response to "Can a civilisation really peacefully exist without destroying itself or the rest of the universe".
On the other note, imagination is such a big advantage of humans, we can achieve so much just by using our imagination. Also the whole topic of "Are we alone and where is the rest" is so interesting!
Unless we are talking about detection from a relatively low range, a range where the square-cube law hasn't reduced the energy we would receive by too much, I would not expect us to ever receive random radio transmissions from other civilizations. Which, ultimately, turns the Fermi paradox on its head: it would be incredibly unlikely for another civilization like ours to develop at exactly the same time as us and so close to us.
Once basic space construction is mastered (which we are very close to), large scale solar collection seems a likely path that many civilizations would take. A Dyson swarm would probably be the first step, which would be detectable from very large distances.
Totally something we should bring back. If evolution as a process could be stuck in local minima, then we would think otherwise - but that is heresy.
dystopias is just as likely
"As we develop VR tech that allows us to simulate any world we desire, recreational or purpose driven, there is less and less reason to explore the rest of the universe."
Using humanity as a example for how intelligent life advances, we can look at the developed nations. The develop nations are the ones who would create any sort of technology that would get us out of the solar system and into contact with other life. Most, if not all developed nations are built through commercialization of products, with the citizens consuming those products. Only a very, very small portion of people are working on the advanced technology to take us elsewhere. So the majority of our species are not advancing galactic technology, but they are becoming larger consumers of entertainment, at least on the scale since early civilizations. Keeping that in mind, we are also somewhat physically locked in our solar system due to the laws of physics, at least in the near term. So, to me it would seem much more likely that instead of advancing space tech to the point where we are sending robots to other planets to self-replicate and spread across the universe, that by that time we would have already perfected VR and that our entertainment-based population would be well-satisfied simply living in our perfect little VR worlds. The two scenarios aren't mutually-exclusive. We are in fact advancing VR and building rockets for Mars as I write this, but I think it's also possible that simulating our reality could replace our desire to move outward. Since the universe is seemingly too far out of reach, we will just create our own here, for cheaper, sooner.
There also is a force which makes humans cluster. Silicon Valley is the biggest cluster of IT and VC at the moment. Accelerando (by Charles Stross) describes vividly how an advanced AI civilisation still clusters (Mainly because solar/fusion power and communication speed).
We got the answer right here. It's much more interesting and probable to meet AGI than aliens. Space travel is dangerous, but virtual space is just as interesting.
Btw, the latest scifi I read on the subject is http://compellingsciencefiction.com/stories/fermis-last-surv...
I am a fan of Bostrom’s conjecture about the simulation, though. 1/3 is a damn high probability. At the same time all the examples we make to wrap our heads around these mastodontic concepts are so trivial and so inherently human, that I wonder how can we really take our own musings seriously. We might be able to escape the boundaries of Earth’s gravity at some point, but will we ever be able to escape the boundaries of our human thought?
Unfortunately, we can't do it any other way, by the very nature of conscious thoughts.
> Why can’t we accept that we populated this world for the equivalent of a cosmic blink, and we are therefore unequipped to even grasp the existence of other life forms?
Why should we? We might be doing a lousy job, but we're doing the best we can.
> At the same time all the examples we make to wrap our heads around these mastodontic concepts are so trivial and so inherently human, that I wonder how can we really take our own musings seriously
It's not like we know of anyone else whose musings we could take more seriously than our own. The known universe, as beautiful and awesome as it is, is also dead.
> will we ever be able to escape the boundaries of our human thought?
If we survive long enough to achieve the ability to re-engineer our minds, I hope so, yes.
We've literally never done this before, so we don't even have a very good idea whether we're doing a good job or not, that's how clueless we are. Signs are pointing to us more or less killing ourselves, though.
It's boring as hell, metaphysical conjecture, suitable for late night bar talk and deus-ex-machina sci fi plots. The 1/3 probability especially is total bullshit. It's fun if viewed as an art project, and as such has some entertainment value.
It does not really explain anything. Unless one enjoys figuring out with theoretical physics, which facets of our world would point out to a simulated existence, it offers nothing of value when seriousy figuring our place in the cosmos.
If it's touring equivalent system, then it's just like being inside a computer.
And if it's not touring equivalent, yet 'equally powerfull', I think you need to invent some new mathematics.
Sure, we don't know what nature is but just inventing fabulous concepts that don't explain anything takes us nowhere.
Similarly, what do we know about hyper advanced technological civilizations with the capability of colonizing galaxies? Basically nothing. So any model we have of them is fundamentally invalid. Even if we pretend that layering on a bunch of "conservative assumptions" can remove that fundamental difficulty of having zero knowledge of such civilizations, it very much does not. At the end of the day this is a problem that is beyond our current understanding and we cannot make any firm statements about it one way or another.
Unless (or until) we meet actual aliens, that is all we can do.
The bumblebee thing is a myth. The rest of your comment is defeatist.
Exactly! Each time when I hear that scientists are looking for water because that's supposed to be a condition for life - I wonder how small imagination one needs to have to think that only "water-based" forms of life exist.
So they're only undetectable as a side effect of being efficient. Not because they're hiding or have all died in a cosmic extinction.
https://phys.org/news/2017-06-wow-mystery-space.html
That's assuming that we'll get to that level by 22nd century (or ever).
I'm not so sure inter-stellar space travel and even space probing at that scale will come to be. Or even a colony as close as Mars -- for the reasons outlined pretty well here: http://www.ecosophia.net/terror-deep-time/
Not the only one. There may well be an armada of these probes on their way, but so far away in one of the billions of galaxies that the metric expansion of space means they will never reach us even at near-lightspeed - or may reach us long after we've become extinct. Or may miss our pale blue dot entirely. It's a freaking big universe.
It's all speculation.
We have satellites and yet know very little of what's happening in other countries. We mistake their needs and intents all the time. We are regularly surprised of what they are capable or incapable to do. And yet those are identical being living in the same spot as us.
- they are interested in expanding;
- they didn't find a better solution to expand than going to other planets;
- their material structure is similar to us (they are physical, they have the same size/speed/time perception as use)
- the universe has no characteristics than we don't know about that could disallow us to perceive them (number of dimensions, or whatever)
- they emit some signals among the one we can perceive;
- they need and use energy as we do and as we understand it;
- they are not actively hiding;
- if we saw them we would realize what we saw.
It's like an ant assuming that because they can't smell pheromones from another hill, there is no life there.
Now, I'm for ocalm razor and I actually thing there is a strong probability that all those assumptions are true. But I don't know for sure that they are. They are just that: assumptions.
That's carrying a lot of assumptions. That there's not a probe lying somewhere in the solar system watching us, that aliens haven't found a better way to observe us than probes, that they even care about observing us in the first place. Take the last one for example - 400 billion stars in our galaxy alone. It's entirely possible that we're not important enough for advanced societies to care, the way you're not going to stop and mess with every random anthill you pass by.
Imagine a couple of tigers talking. "Someone says there are 9 billion humans in the world." "That makes no sense. Take the amount of good hunting habitats in the world, divide it by the amount of territory an adult male would need to call their own, and divide that by the number of humans. You would have multiple humans fighting for each chunk of territory, and marking their scent everywhere. Yet I don't smell any human urine so the question is...where is everyone?"
As an aside, why do people focus so much on self replicating probes? Assuming aliens did want to send out a probe fleet - why not simply mass produce probes in one system (or a handful of systems) and send each in turn to their destinations? Having to accelerate, decelerate, build a probe, have the new one accelerate, decelerate, build another probe, have this new one accelerate, decelerate, etc., seems like it would take a lot longer than simply sending a probe directly to its destination (no need to constantly decelerate along the way, no need to waste energy moving replication units, etc.).
That doesn't mean that they are optimal. The Fermi paradox does not care about optimal, just possible.
At interstellar distances, it is very difficult to detect something unless it is emitting something: electromagnetic energy or gravitational waves (and those are only possible to detect when there are super-massive bodies doing something extremely energetic, like two black holes or neutron stars merging).
Earth's man-made electromagnetic radius is about 110 light years. We're pretty much invisible to any other life out there.
But what about aliens that have been around for a long time? Wouldn't we see some evidence of them?
Well, the other problem is that space itself is expanding. The observable universe is 91 billion light years in diameter, but as space expands, the farthest galaxies are receding from us at ever-increasing speeds, eventually becoming invisible to us as well.
The unimaginably vast spatial and temporal scale of the universe means that countless alien civilizations may have come and gone, along with any sign of their history if their light waves are outside of our observable universe. Or their signals arrived and ceased long before humans even existed, let alone had the technological capabilities required to receive and interpret such signals (arguably, only since the advent of digital computers).
Factor in the 100 billion (or maybe 10 times more[1]) galaxies that we can see, and the 160 billion stars (solar systems, possibly) per galaxy, and the probability that we will detect an alien civilization (or vice-versa), where we are and when we are, in a universe that is mostly empty space, before we ourselves die out, seems rather small.
[1]: https://www.spacetelescope.org/news/heic1620/
And then, how long are we to last with this capabilities? We are much less smart than most believe, especially in preserving conditions for a communicating civilisation.
Why bother using humans to extract anything when there are other, more efficient, ways of harvesting? That's just "ancient aliens" conspiracy theories if you ask me.
Level one civilizations can harness the entire power of a star for communication.
https://en.m.wikipedia.org/wiki/Kardashev_scale
“Dissolving the Fermi Paradox” http://www.jodrellbank.manchester.ac.uk/media/eps/jodrell-ba...
For example, many explanations are of the type "Well, maybe the aliens are all doing X," but it requires every independent civilization to be doing that, with no exceptions, so that we haven't even detected one variant, not even one that needed to escape its star and colonize the galaxy, which many experts find unsatisfying. I found the book to be a fun and quick read that touches on a lot of scientific/comsological/biological/etc concepts.
(Looks like he has a newer editing with 75 explanations...[1] I haven't read that one.)
I see the article also mentions the simulation hypothesis. Personally, I'm intrigued by the overlap between secular simulation hypotheses and religious notions of the universe having a Creator.
[0]https://www.amazon.com/Universe-Teeming-Aliens-WHERE-EVERYBO... [1]https://www.amazon.com/Universe-Teeming-Aliens-WHERE-EVERYBO...
The fermi paradox is not really a paradox if it is based off of a probability that we don't even know. Once we know the conditions and steps it takes to form life then we can take a stab at estimating this probability.
Don't trust your intuition on this, while the universe is incredibly large, nobody knows how infinitesimally small the probability of life spontaneously arising from base elements is.... Additionally, we need to know the probability of having this life form evolve into something that can communicate across space.
There are things around you that have nearly zero probability of occurring again anywhere in the universe. Unless you have a twin, the probability of someone being born anywhere in the universe with your exact configuration of DNA is nearly zero. It is possible that the formation of intelligent life shares an equally small probability. Again, we don't know this probability until someone is able to recreate it.