If Loud Aliens Explain Human Earliness, Quiet Aliens Are Also Rare
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1. The speed of light is a hard speed limit. This means there's also no cheating with warp drives, other forms of FTL, crossing dimensions, parallel universes or time travel; and
2. The laws of thermodynamics as we understand them hold true.
then the outcome of spacefaring civilization I believe is generally inevitable. That is, the ultimately limiting factor is energy and mass.
The easiest way to get both is with Dyson Swarms. This requires no new physics and no exotic materials.
If so, then a galaxy-spanning civilization is going to be completely obvious from a million light years away from the spectrum. Why? Because a full Dyson Swarm would have a very unique spectrum, specifically very little visible light and a lot of IR. That's just basic physics. The only realistic way to get rid of heat in space is to radiate it away and the wavelength of that is a function of temperature.
This is discussed in the context of the Fermi Paradox, which has the advantage that you don't need to determine what every alien civilization does, you just need to know if there are any exceptions.
Example: if there were 1000 spacefaring civilizations in the Milky Way, what are the odds that all 1000 of them (assuming they were within out light cone) would remain quiet or hidden? Couple that with mass and energy ultimately being limited then there is a strong incentive and advantage in becoming as large as possible. So even if 99% of civilizations remain quiet, the 1% will still make themselves visible.
Additionally, on the notion of hidden civilizations in particular, it's essentially impossible to remain hidden to a K2 or K3 civilization so there's really no point.
This is what gives me confidence that the Milky Way isn't teeming with spacefaring life. In fact I consider it much more likely we're the only such civilization in the Milky Way (within our light cone).
They're also full of what were at the time good theories, but that are now so wrong it often makes reading the story difficult, even with my fairly rudimentary modern astrophysics knowledge.
In all honesty I think it's more likely any sufficiently advanced civilization capable of interstellar travel has probably descended entirely into virtual reality or a singularity.
I mean, what would you prefer? Being the star of your own personal VR space, the next Malcolm Reynolds, space cowboying around where you are the entire focus of that reality. Or schlepping it over to another star in a generation ship or whatever where even if you were somehow still alive when it arrived, you'd be landing on a planet that will probably instantly kill you.
1. We're now assuming based on the limits of known physics rather than the expected limits of technology. My father told me he once read a book that said it was impossible to go to the Moon because it would take 750 years to get there. The speed of light was known at that time but assumptions were made about the limits of acceleration and velocity that weren't grounded in science;
2. Things like the rocket equation are important. Specifically, the reaction mass problem. Even more specifically, the only way for an independent body to accelerate in space that we know of is by expelling mass (or energy). You need to carry that mass and this quickly becomes inefficient.
A good example of this is how people have recently started to say "if we just accelerate at 1G we can get to Alpha Centauri in a few years". 1G acceleration sounds easy but it's not.
So how would you travel between stars? I think it most likely that you'd use a ton of energy to accelerate (or decelerate) a vessel with lasers on a solar sail. Why? Because energy from a star is abundant and cheap and it doesn't require carrying reaction mass.
If you accept that, then the need for Dyson Swarms becomes more obvious.
3. Breaking the 2 assumptions I listed makes spacefaring life more common not less. By this I mean we only really need to consider a million light years (of light cone) because of the speed of light. If FTL or even time travel were possible, then you need to consider a volume of spacetime orders of magnitude larger.
A bit of a tangent, but that seems absurd even based on knowledge from hundreds of years ago. The moon is about 250,000 miles away, so the 750 years figure assumes a speed of less than 1 mile/day. And a quick google search suggests that we've had reasonable estimates of the distance to the moon since about the 2nd century BCE.
That's the thing that usually trips us up.
Also, on a more human level, who's going to even pay/bother with these swarms? What will they achieve?
I would not choose to be the star. Observing substance (ab)use and suicide among celebrities and the affluent, it seems clear that a “starring role” in life is not an automatic ticket to happiness or fulfillment.
For me at least, a lot of the meaning in life comes from dealing with cold hard reality. Updating my strengths and my belief systems to be more aligned with a disinterested external world. Connecting with, learning from, and sharing with other humans what it all means and what it’s like to be part of this whole thing, to get a more complete understanding of the human experience.
Consider—if we were one unified consciousness with total understanding existing in absolute bliss, what would there be to do, to discuss? We might produce a limited world like our own to make existence more meaningful.
Imagine being able to deliver REAL experiences as ads:
"TRY our new toothpaste. Really!"
So like everything in technology we will just kind of evolve into it without even noticing until it's too late like Facebook or some such.
Even in a virtual reality (perhaps especially in VR?) I’d fear that a single instantly connected human society would stagnate pretty quickly.
At least sub-light speed travel and communications limit would allow future human colonies to grow independently rather than our increasingly homogeneous worldwide consumer culture.
Moreover, even if you do descend into VR, if you have a civilization capable of safely doing that, you need to explain why 100.0000...% of them never say "hey, I sure could have a lot more VR resources all to myself if I just sent this probe over to that star system over there and converted it into computronium".
By the time you get to this level, you don't need to worry about "planets that will instantly kill you".
Some sort of "singularity" where they escape our universe would explain the emptiness of the sky. However, every year the places where such a thing could hide in our physics gets a bit narrower, and we have literally zero reason right now to believe that such a thing is possible. I have no problem speculating, but I prefer to keep the grounded and ungrounded speculation clearly delimited, and right now this is definitely on the ungrounded side.
(Side not, not targeted at you mattmanser but just to prevent me posting another message, it's really tedious to attack someone engaging in grounded speculation by pointing out that ungrounded speculation exists. Yes, it's possible that humans are just uniquely stupid and there's some easy mechanism to create and escape into infinite energy subuniverses and half the planets in the universe have had dozens of alien civilizations already do so, it's possible that aliens are using energies we've never even heard of to communicate, and it's possible that psychic waves are radiating right through us this very second telling us how to do it, but that's ungrounded speculation. It doesn't mean that we must therefore give up all grounded speculation because "what if, like, the aliens are all psychics that escaped into the ninth dimension? you can't prove they aren't, man.")
But in the real world? Actually make a Dyson Swarm? Elon Musk is trying to go to Mars with the help of thousands of people directly and the indirect help of hundreds of thousands of people. It takes a huge collective effort for an engineering task so big.
Yeah, sure there might be a few 'real worlders', but it'll be a lonely place out there on their own, they'll have no infrastructure, no backing, nothing.
So while they may want to build that Dyson swarm, they won't be able to.
There might even be all sorts of laws in their way to make sure no-one can spoil it for everyone else by eating up resources unnecessarily or putting others at risk.
As for your side note, the speculation was about what's most likely, not what's possible.
My point is that while Dyson swarms might be theoretically possible, my belief is that they're not practically possible because by the time you reach that level of technology, society will have already moved to a different reality.
And mine is a speculation just as much as the GP's.
Even if it was possible, what would "descend" mean -- it would mean that someone could make a perfect virtual clone of me inside a virtual world.
What is the incentive for ME to do that? It's like saying that in a parallel universe a perfect clone of me is a billionaire if I so choose.
> singularity
What does that actually mean?
Or instead of growing larger, growing smaller and becoming more efficient. Microscopic organisms with free will wouldn't be needing Dyson sphere to power their civilization.
Or realization that existence is a pain and that there's no point in pursuing it after the civilization reaches certain level. This is a conversation-ender, So wouldn't even make a good Sci-Fi unless say that civilization decides to put every other civilization out of their misery due their ideology.
Sure, we haven't seen a Dyson swarm, but it's not like we've been looking super hard, and we're assuming that a Dyson swarm/sphere is practical to make and build. If a civilization were to develop a way to, say, directly convert matter to energy, the Dyson sphere/swarm is actually the less efficient option.
The thing is we know about natural phenomenon. We don't know whether aliens exist and are detectable. Occam's razor would favor existing natural explanations. Stars, planets, comets and what not are common throughout the universe.
That's kind of my point though. We have tons of astronomical data, but except for neighboring systems it isn't precise enough to unambiguously detect an extraterrestrial civilization. So we go with the natural explanation for what we see, because Occam's razor would seem to suggest that. But by definition that means that if the universe has alien civilizations producing megastructures we would first assume those were natural phenomena. And then we would try to find explanations for these phenomena, and build models, which would be incorrect, but would provide a natural explanation for these megastructures. So, ironically, if the galaxy really was teaming with alien life and alien megastructures, we would likely just categorize it as natural phenomena, and wonder why we aren't seeing any signs of alien life.
I agree that just stars and planets and such are very common and thus unlikely to be alien megastructures. And I don't think there are any objects we've documented that are unique in all the universe. Any potential candidate would have to be something relatively rare in the universe (but wouldn't have to be unique) and would have to be poorly understood (something where we haven't directly observed its formation, or it has properties that aren't explained by physical laws/phenomena that we've been able to validate in a laboratory setting) to be a candidate. As a stab in the dark, consider pulsars. Fairly few known in the galaxy, from reading the wikipedia page it seems like they have some particularly weird and poorly-understood properties. They rotate and emit radiation very precisely, precise enough you can sync atomic clocks to it. It's been proposed that you can use multiple pulsars as reference points to very accurately determine your location, like GPS (https://en.wikipedia.org/wiki/Pulsar-based_navigation ). They emit huge amounts of radiation and are very small, meaning it would be much, much easier to extract energy from it Dyson-swarm-style. To be clear, I don't know much about astronomy, and I think that pulsars are almost certainly NOT alien megastructures, but I'm just pointing to it as an example.
Unless you can transmit power over infinite disctance without loss, you get diminishing returns as you expand. Eventually the amount of energy you can beam back from a new dyson swarm does not justify the cost of building a new dyson swarm. There is no incentive to expand beyond that point. For reasonable engineering estimates, such a range is still very small on galactic scales.
This would make Dyson Spheres unnecessary for advancement on the Kardashev scale.
Even if that were possible, it's only 6e-10 J/m^3 [1].
Want to keep a 10W LED light on? That's 10 J/s, so you need to extract all dark energy from 17e9 m^3 of space (roughly a cube with a side of 2.5 km) every second.
[1] http://www.astronomy.ohio-state.edu/~ryden/ast162_10/notes41...
We can already create W bosons from photon collisions at particle accelerators on earth.
I am not sold on this math necessarily. When you ask "what are the odds?" what is that based on? How do we derive these odds at all? We know nothing about how these civilizations would evolve or what their values would be. So how can we assume that out of 1000 that 1% would be visible based on the odds? This sort of assumes that the Drake Equation is accurate, when the last few parts of that equation are complete guesses.
> Additionally, on the notion of hidden civilizations in particular, it's essentially impossible to remain hidden to a K2 or K3 civilization so there's really no point.
And maybe this is the difference. Maybe all 1000 are visible to K2 or K3's because it doesn't matter. But equally all 1000 aren't visible to K1's. We are so far away from K2 that I see no reason to speculate on the likelihood of this since we have literally no basis for this other than some fun thought experiments. And all of this is based on how we view ourselves and apply those same traits to beings we have never met and possibly can't even imagine.
This is simply so far out of our grasp to intelligently speculate on, I tend to just avoid doing it.
As a result, the Drake equation can have any value from “billions and billions” to zero. An expression that can mean anything means nothing. Speaking precisely, the Drake equation is literally meaningless, and has nothing to do with science
https://stephenschneider.stanford.edu/Publications/PDF_Paper...
That sounds just like a brown dwarf. How would a Dyson swarm look different?
If (big if) you can be confident about the distance of the object, that'll help tell you the total power output. If you have total power output and the black body spectrum, you can gauge it's size. A brown dwarf is, notably, small. If you took Sol and put a dyson swarm around it, the eventual power output would stay the same, just shifted colder as the light is now the waste product of all the industrial activity we did with it (minus any anti matter or magic matter fabrication we did) as opposed hot plasma collisions.
Parallax, which I mentioned, can be used for measuring the distance. I'm asking if there are better alternatives for getting the distance.
For objects that are sufficiently far or slow moving, we can use Earth's natural movement to get some 2 AU of parallax base. Simply wait half a year before pointing the telescope at the object again. But, for things that move fast enough and are close enough to get some arc offset, we'll get wrong results. Which maybe isn't a problem, because we can detect such movement outright? I literally have no intuition how the math here works out. Hence asking.
If you put a shade around a light bulb the amount of visible light will be reduced however if you measure the total output of the lightbulb with or without a shade it would remain the same just more shifted towards the IR spectrum as the shade would absorb visible light will get hot and emit that energy as IR.
Then why would it definitely be IR? Couldn't a different form of intelligence thrive at a completely different temperature, and rely on elements that have phases that are useful to them at different temperatures?
Compare those two and you'll see pretty much any reasonable range of temperatures has a heavy IR element.
Some things to consider:
1. Tungsten has probably the highest melting point at ~3700K. It seems unlikely that complex matter of any kind can realistically survive at such extreme temperatures;
2. Heat above a certain level can itself be used to generate energy in a straightforward fashion. This itself will generate waste heat, most likely at a much lower temperature.
As an aside, recycling heat is often raised as an objection to the IR signature issue with Dyson Swarms but that ignores thermodynamics. Let's say heat recycling for a star like the Sun is 90% effective then that's still 10% energy lost and 10% of the Sun's output is still massively significant.
If there's perfect recycling, well that ignores entropy.
[1]: https://en.wikipedia.org/wiki/Wien%27s_displacement_law
[2]: http://labman.phys.utk.edu/phys222core/modules/m6/The%20EM%2...
Also, how do you tell the difference between a solar system full of orbitals vs. a young solar system that has not had the orbital lanes cleared by planets?
As for the second part, that's easy. There are two key differences:
1. Young solar systems are around young stars and young stars are... young. We can typically age stars, particularly those close by; and
2. A protoplanetary disk is, well, a disk. A full Dyson Swarm is a sphere. To be clear, it's not a rigid sphere, it's just a collection of orbitals that end up occluding the star they orbit in the same way as small water droplets form a cloud or fog.
Alsos I suspect that a protoplanetary disk, even if we're directly on its plane, won't be as dense as a Dyson Swarm.
The sun puts out 3.846×10^26W. Let's assume a Dyson swarm manages 10% capture efficiency, and a future population of 100 billion. That would result in every person having access to 384TW, or about 25 times Earth's total power consumption.
Clearly, that's far too much power for any reasonable use-case, so at that point you're talking about either a far higher population (quadrillions) or far smaller collection area. Earth's population seems to be destined to cap out at about 9bn, and the trend away from population growth is most pronounced in highly developed energy-hungry countries. So _we're_ probably never going to need a Dyson swarm, anyway...
Second, it's entirely valid to ask the question of whether we'd ever reach such populations. This is of course unknown. As a solution to the Fermi Paradox, the idea of reaching a steady state (or even shrinking to a fragment) seems unsatisfying as a 100% outcome. Once again, it only takes 1 to keep growing and become detectable.
A lot of things are likely to change in the next millenium, for example:
1. I expect we will live much, much longer than we do now;
2. Automation will increase to the point where labour is highly unlikely to be the limiting factor in any kind of industrial output. That leaves resources and energy as the limiting factors. Well, resources are just a proxy for energy. There are several rocky bodies in the Solar System that could, given enough energy, provide unimaginable amounts of raw materials;
3. Despite the wealth of developed nations, we are still living in an era of relative resource scarcity. Individuals in developed nations are certainly generally more prosperous than those in developing nations but it's expensive to raise children in developed nations the way most parents want to raise them: paying for education, housing, etc.
I'm not comfortable making the prediction than the modern trend of having relatively few children per individual in the developed world will continue into an era of longer lives, far more abundance and being freed from the need to work their entire lives to set up those children.
Lastly, there are some very obvious applications for huge amounts of energy, for example:
1. Extracting resources;
2. Vast amounts of computing power. What would you do with this? We haven't been good at predicting this other than to say that more bandwidth and more computing power has thus far always found applications that people want. One obvious one is I suspect we'll have VR worlds that people will basically live in on a scale we can't possibly yet imagine;
4. Interstellar travel; and, of course
5. Cryptocurrency mining. :)
Where have I heard that or something similar before? ;-)
There could be quintilions of amish people farming in a Dyson Swarm :)
Realistically, it's not just urbanisation. Back when people regularly had 15 children, that meant that people were (a) basically continuously pregnant for 15 years and (b) spent around 30 years of their life bringing up children. Even without economic constraints I doubt it would be a very common approach; if nothing else you don't see that many billionaires with 15 children.
My money is on it being too infeasible engineering wise due to resource exhaustion just building the infrastructure to get there. The carbon feedback loop creating disposable junk is destabilizing stable human climate.
I lean towards the idea we’ll have to move away from industrialism at the scale we apply it today.
Perhaps synthetic drugs can grow neuron structure that mimics the experience. Or helps acquire muscle memory from skills based work.
Trip balls on the couch for 20 minutes and live life believing I just got from Mars Base 1 and have Zappa opening for me wouldn’t be so bad.
Because aliens are here, and they certainly didn't travel at the speed of light to get here. That doesnt work at all. It's way too slow.
My bet is they are extracting energy from space itself, what we call vacuum and we think there is nothing there. And I also think the speed of light only applies to things in our physical universe. Frequently these alien ships blink in and out of our reality. There is much we don't understand as humans.
Bear in mind that we humans are a spacefaring species. It seems entirely feasible to me that there could be a multitude of intelligent but "quiet" species limited as we are to probes and at best inter-system rockets, even that 100% of spacefaring civilizations thus far remain so, simply because getting to the "Let's Dyson swarm our sun and become Vorlons" stage is far, far more difficult than it appears on paper.
It could be that Dyson Swarms are possible, but we have 0 examples of space industries so far.
It could be an economical impossibility, it could be that the means to easily convert matter into energy is discoverable before the means to economically produce a Dyson Swarm, thus a Dyson Swarm is not necessary to orbit that close to a Star.
It could be that the means to capture dark matter is right around the corner, so there's no need to estinguish stars to preserve them.
It could be that the means to capture dark energy is also around the corner and there's no need to bother with altering the universe in any way, in fact, it would be a shame to do so.
It could be that once a species is advanced enough to transcend its own biology and once it becomes kind of immortal, it no longer reproduces.
I'm just pointing out counter arguments, I'm on the opinion that we are completely alone in our Milky Way and most likely the entire Universe. As in there is no bacteria outside our Solar System, anywhere, but there is no way to know yet.
You can apply a very similar reasoning to an isolated tribe stuck at, say, stone-age level on a remote island. With barely seaworthy canoes. They very likely have no idea we exist, and their assumption will be that if there were better canoes, and people had them, they would've made contact. So clearly, they must be among the first.
I am continually amused by the gyrations we go through to avoid saying "we don't know".
I mean, last I checked we couldn't even account for 85% of the matter in the universe that should exist according to the laws of physics as we know them. If we can't even find the vast majority of matter, why do we think we'd do better with civilizations?
1. aliens spread at a certain speed after developing spaceflight
2. they're not here
3. there are no spacefaring aliens in the galaxy currentlyAssuming FTL isn't possible, the fact that dark energy makes large sections of the visible universe fundamentally inaccessible is probably a good thing.
Otherwise that is a lot more of the universe that may be ahead of us and would stomp us like ants.
You could make the argument that it does appear that life is fundamentally adversarial, seeing as in our one example all life feeds on other life, and to sustain life a creature must kill. I believe that's simple a circumstance of limited biomass in a closed system and so not fundamental, but you could argue that all civilizations probably get bootstrapped in this way and so it doesn't need to be fundamentally adversarial, but that all civilizations are accustomed to it so the distinction "fundamental" does not really matter. I'd disagree with that also, because a change in conditions to post scarcity changes conditioning and therefore behavior.
You might also come up with a prisoners dilemma type scenario where a civilization doesn't want to be adversarial, but it doesn't know the intentions of others and so to protect itself, as a rule, destroys any that it finds. This is somewhat plausible but I don't really think likely because civilizations that evolved from abiogenetic origins separate from one another would likely have very very different behaviors that might not even overlap in many cases, so even if they were aware of each other they may not even be capable of interacting.
It just does not make sense for a space faring civilization to be hostile. A requirement for space faring and a result of it is post scarcity; resources abound in the vast swathes of dead universe. There is no reason to even think competitively, barring some as yet undiscovered unobtanium so rare and so powerful that civilizations fight to extinction over it, but I doubt it. If anything, I'd think that a space faring civilization benefits the more it understands the universe, and learning about biospheres and civilizations with completely different evolutionary paths from abiogenesis would be more valuable than destruction of them.
The limitation could be doubling time not travel time. Sure double every 100,000 years or less and in 4 million years you’ve run out of stars in the Milky Way which is an eye blink on cosmic timescales. But, a civilization that’s remote terraforming worlds that might greatly slow things down. How long does it take Cyanobacteria to create an oxygen atmosphere for example?
Certainly no-one would make the claim that "there are (definitely) no aliens in the galaxy" when we can't disprove the idea that aliens traveling at the speed of light just reached the galaxy (with our current understanding of physics). That doesn't mean you can't make the claim "there are (almost definitely) no aliens in the galaxy (because I just created the most amazing telescope ever and looked at every particle of matter in the galaxy and there were no aliens there)". The principle of charity demands that understand the bare claim that "there are no aliens in the galaxy" to mean something that is plausible, such as "there are almost certainly no aliens in the galaxy".
Well, what matters is expectation. The fact that some people win the lottery doesn't prove that playing the lotto is profitable. In fact it isn't money-profitable. The fact that people sometimes win doesn't change the nature of reality, that even for them, the win is unexpected and playing was negative expectation for them.
You seem to be confusing expected value with results.
Do you revise your decision process every time you get unlucky? On a meta level, sure, paying attention to unexpected failures is important to look for systematic errors. But randomly getting unlucky on 99% certainties does not automatically disprove your decision method.
For example, when asked to be more granular, the turtle could say 'I reason that there is only a 1 in 10 chance that seafaring civilizations exist'. The existence of seafaring civilizations doesn't make the turtle wrong in this case.
If the turtle concluded that 'there can not possibly be any seafaring civilizations, because I don't see any' then you could accuse it of bad reasoning.
The hypothetical turtle did exactly that, loyally following suit with the commenter who I replied to.
Also, since he’s a turtle, he doesn’t, presumably, yet actually know how hard it is to make a boat. The argument for determining whether or not you are the only seafaring species depends, first, on you having attained the ability to travel the seas…
All of that seems necessary before he can conclude whether or not he should consider it ‘surprisingly late’ for his island not to have been reached yet by any seafarers.
But the interesting part of the analogy is maybe that the turtle might fool himself into thinking he understands the parameters well enough to estimate this probability - after all, he’s paddled around off the beach and even made it to a nearby rock - so he reckons he’s got a pretty good handle on how hard it must be to travel between islands.
Ignorance and misestimation of the true underlying factors isn't a trait unique to these hypothetical turtles.
Or, perhaps you have a much higher confidence than I do in humans' assessment of the factors involved in your questions.
I'm saying we are over-confident in the underlying premises of our understanding, just like the turtles would be. The more of the questions you pose that go partly unsolved, the more unsubstantiated the conclusion. Their probability calculations are pointless -- garbage in, garbage out. As demonstrated by the patent wrongness of their conclusion.
If you are confident that we've got solid answers to the interstellar corollaries of all your questions with the evidence we can gather at this point, then we aren't on the same page at all.
This idea, that our observations of the universe are a properly representative sample from which to form conclusions about the unobserved universe, makes as much sense to me as the thinking-turtles assuming you need a small green island to and a thick shell to enable sentience because that's what their observations show.
And at that point, where is the incentive to colonize other star systems? You're still probably not going to be able to move a meaningful part of your population, and if you can produce energy that cheaply you can sustain a large population in comfort at home.
It's not inconceivable that there are advanced aliens all over the place, but that interstellar travel is basically limited to probes for pragmatic reasons.
I think when the Fermi Paradox was brought in, there was still some lingering Malthusian idea that geometric population expansion was inevitable. We now know it very much isn't, at least for us. That changes things.
If reactionless drives remain science fiction this mode of travel is flat impossible. There literally isn't enough mass in the solar system.
Should we want a colony on another planet? In another star system? Absolutely. It doesn't take much expansion for us to achieve the goal of having a 'redundant backup' for humanity.
Beyond that, there has to be some sort of economic incentive to drive it. Given there is little chance we can economically trade between planets, much less between star systems, I don't think that incentive is there.
Let's consider extinction mitigation as a luxury? I posit that sooner or later, as technology improves, the relative cost of such projects will go down to a point where some group of people think it is a good idea.
I don't think new discoveries suddenly change the physics of escaping gravity wells. I question whether interplanetary trade will ever move beyond intellectual property.
Basically, colonization will have to be altruistically funded without any expectation of economic return. We've proven we have limited capacity for that.
Currently.
In a system where resources are allocated not to cover the needs of all, but instead to ensure that the victor gets their spoils, this is true.
But IF a civilization makes it to a point where self-sustaining planet settlement is even a real possibility, I think you just have to assume they are post-scarcity and post-currency. Economic return isn't really a thing, if everyone can get what they want whenever they want it.
Therefore, any species with a natural propensity to exploration and curiosity as an individual is going to necessarily seek out new places as a whole. The individual will drive the societal, I guess is what I mean there. Because I want to see something new, and there is no scarcity of resources, society as a whole gets to see something new.
>I question whether interplanetary trade will ever move beyond intellectual property.
Honestly, I don't think so. Because, again, I'm of the firm belief that once a society is able to establish off-world colonies successfully, economics stops meaning anything at all, really.
You might _explore_. You're less likely to _colonise_. The only way you get the sort of geometric expansion people love to talk about is if there's a very strong imperative to colonise, and it's just not clear that it exists.
But humanity is not doing that. The current trend is world population will peak at just over 9 billion in about 30 years. Trends can change, but that is the current one.
And notice that people from different star systems in the same civilization will very likely only have extremely rare direct encounters due to the brutally long distances involved... it's highly likely the civilization will split up into completely separate "star nations", with their own internal issues to keep them busy and at some point may lose interest even in communicating with other star systems... without any incentive at all to expand further as the species survival is guaranteed... curiosity wouldn't be strong enough, probably, because after getting to know several star systems, you may decide they are look more or less the same, and to find anything really interesting might take multi-million year journeys and no one would be able to embark on something like that just for curiosity.
I can't think of any phenomena that could come close to doing such a thing. But if there was one, why couldn't it be like gamma bursts?
If you're scared of nasty aliens, the best defence is to conquer the whole galaxy before them.
There is no way to hide from an interstellar civilization.
Nasty or not, they could always produce self replicating probes and keep track of the whole galaxy.
Also, if you were able to colonize a couple of Star Systems, there's no way you are an anxious/scared species,
It's easy to know where to go next when we only have one option to pursue (such as travelling to the next nearest planet or star). This is a lot like the early web when there were only a handful of interesting sites and discovering new cool sites was a goal in and of itself.
Today, I think we intuitively understand that there's no longer any value in trying to visit every website on the internet. Most sites offer zero value or even net negative value. The entire problem space pivots to one of knowing which 0.00001% of websites are valuable to a given situation.
When a civilization gains the ability to visit any planetary system, the problem shifts to one of filtering choices and information to minimize the amount of unnecessary travel or world-settling.
I assume this is a well-known concept. I'd love to read more if anybody knows what it's called.
Don't see the reasoning here.
For example, we currently can feed the whole Earth population "cheaply". But the wars didn't end. Same with cheap energy.
E.g. we can try to install vast amounts of mirrors to direct Sun's light towards an accelerating ship. But that won't bring us here more comfort.
An example:
We have 1000 stars within the 30 light year radius neighborhood. Traveling at Voyager 1 speed, it takes half a million years to do a 30 light year trip. [1]
Given another half a million years for bootstrapping at the destination for ten more probes, we can send ten more probes, 1 million years from the launch of the first one. At two million years we get 100 probes.
How many probes do we get in a 11 million years? 10^11 probes. We have 10^11 stars in the galaxy.
Dinosaurs roamed the earth aleady 200 million years ago, and died in the mass extinction 65 million years ago. 20 to 5 million years ago was the Miocene, when life was pretty close to modern already. [2]
It's really the nature of exponential growth that makes things seem instantaneous compared to celestial phenomena or evolution. Colonizing the galaxy, even with abysmally slow speeds, is possible, because of the magic of exponentials.
(Certainly this has a lot of assumption, like that you can bootstrap, or that the probe survives the trip. Anyway, optimal probes would be a lot faster and bigger, and there would be more of them. This was just to tie in with something concrete that we know we can do, as Voyager 1 really is out there traveling at 15 km/s, as are Voyager 2, Pioneers and New Horizons probes.)
1: https://www.wolframalpha.com/input/?i=+30+light+years+%2F+vo...
So to explain the fact that the aliens aren't swarming everywhere because they can't afford it means accepting that either they launching a single generation-ship every 5000 years is a huge expenditure (which IMHO it wouldn't be even with our current economy size, definitely not an issue with the tech of 2100 or 2200 assuming at least some growth because at that point a Musk-type figure with a wish to "make humanity interstellar" would be able to afford it from private funds) or that we're the first (only?) life in galaxy or that all the aliens before us didn't try to expand, like, at all - because getting just one single rich eccentric every 5000 years (like a bunch of billionaires here are) would be sufficient to make the galaxy swarm with juuust a bit higher tech level than ours now.
I'm sure we are absolutely not capable to do that now. Maybe with AI.
But we haven't done that with our Moon and that's not even a few lightseconds away.
Just to put this out there, unless every advanced civilization becomes a hive mind with one unified will, some individual or splinter group or just hodgepodge of determined individuals would probably do it even if there were no incentive, and that's not to point out that incentives are somewhat subjective and differ between individuals and groups. If there are enough individuals on a civilization and the capability exists, some crazy person will do it.
1b. Assuming you can solve 1. with some kind of magical alchemical spares-generating technology that never fails, the technology also has to be politically and philosophically stable, with reliable and persistent goals. Otherwise you'll get offshoots competing with each other. Which may mean undermining and perhaps even destroying previous settlements. How much independence is enough? How accurate are your initial models going to be?
2. We don't know that for sure. Absence of evidence is not evidence of absence. (We do know weird things happen, but we're not putting any serious effort into researching them, so we don't know what they are.)
3. There's no need to think about this after 1. and 2.
Edit: to put this in context, you don't need to launch a probe. You need to launch a complete perfectly self-reproducing error-free space program. Which can also adapt to local resources.
This seems... difficult.
What is "volume appearance" BTW?
And once you factor in how inhumane it'd be to send children out to colonize foreign solar systems ... are we really sure we'll do that? That's 10 generations that live their entire lives in small metal boxes ... without the vast majority of everything we have on earth. Not so much as a single field of grass (or field of anything, building a big room in space will be a great challenge, especially since weightlessness means you don't really need room).
10 generations that will have absolutely zero power to do anything about their situation. It will take 100+ generations before anything remotely resembling earth level comfort will happen (assuming the planets encountered can at any point support human life. If they need to be terraformed, we're easily talking 1000+ generations)
That’s if civilizations even live that long in the first place.
Kinda comes to calculation that when earliest potentially space faring civilisation runs out of their sun? And can't adapt to live in system. For us that would still be at least few billions of years if not more with proper preparation.
Who am I kidding, they would still fight over it...
Higher technology levels have only increased the efficiency of our power use and use per capita. I'm not saying we're at the height of technology or development or anything but the idea we'd need a whole star's worth of power output for something I think is ludicrous.
If you've got the technology to build a Dyson sphere (or swarm) it's unlikely you'd actually need to. To even get to that point as a tool-using civilization you couldn't have had unchecked geometric growth. Unless you had some Motie-like biological imperative to reproduce uncontrollably your civilization would reach a point long before Dyson sphere level where it worked fine without having to move the mass of several solar systems around a star to capture some high fraction of its power output.
I think it’s just as likely that we never spend the engineering effort on a multi-generation colonization ship. Compared to inner-stellar travel inter-stellar travel requires much much more space, robust systems, and reliability. For example, the distance between Earth and the nearest star is over 100,000,000 times the distance between Earth and Jupiter. It’s questionable we’ll ever put the effort into being inner-stellar, but the difference between inner-stellar and inter-stellar is greater than the difference between a paddle board and an aircraft carrier.
If in those time spans we figure out a way to sustain 1g acceleration throughout the trip (currently not achievable but less sci-fi than FTL) we can reach nearby stars within the lifetime of the astronauts: https://www.forbes.com/sites/startswithabang/2021/12/30/how-...
The problems you're raising are far more technological in nature than fundamental IMO. I agree that as it stands it wouldn't make much sense to attempt to colonise the galaxy even if we had the rocket technology today, but by the end of the century we'll probably have the kind of technology required to colonise the galaxy (robots, AI, improved battery tech) even if we're still stuck with slow combustion rockets.
Also imagine if humans do go out and colonize new planets, these people would go through rapid changes morphing into another subspecies each adapted to conditions of the planet they moved to.
Even if one assumes we can make such long lived machines, the question becomes why? By the time such a craft reaches its destination, every being that worked on its construction, and all of their descendants for many generations, and indeed possibly the civilization itself, will be gone. Even if some institution still remains, it will be too far away to communicate with, nonetheless transfer anything with mass. Whether operated by cloned beings or AI, this new settlement is in no way a part of the originating civilization, at least not any more than some ancient Egyptians shipped off 1000 lightyears away would nowadays be a part of ours. There may be legitimate reasons to set up a few colonies, such as backups in case of solar-system scale catastrophes, but by the time you've expanded out even just 100 lightyears (0.0001% of the galaxy), there are already tens of thousands of systems in your "empire". Of course civilizations don't need to act rationally all the time, even though they might derive no benefit they might do something just because they can. But how many times are they going to do this just because they can? 10 times, 100 times? 10,000 times? Eventually the novelty is going to wear off, and those massive quantities of resources being spent on these extremely expensive spacecraft are going to be repurposed for the betterment of the civilization.
Now let's say that, despite the extreme technical challenge of travelling more than a few tens of lightyears, and despite the complete lack of rational reason to do so, a civilization decides to just keep expanding anyways. Eventually they are going to encounter another civilization. This continuous growth is a threat to any other civilization - even if they agree to leave their neighbors alone, they are still ravenously consuming the resources in the area that such a civilization would want to have access to in the future. It is in their best interests to get the expansionist civilization to stop - possibly by diplomacy, possibly by other means. The expansionist civilization is squandering resources on its expansion, it's likely a young civilization that only recently developed the means to expand, its periphery is thousands of years less advanced than its core region and likely very underdeveloped, it has no means to move its assets to the periphery or concentrate its forces in the short term, and it has extremely long supply chains in the long run. Conversely the neighbors have been using their resources efficiently, they may have been around for a very long time, and they are operating close to their core region. The expansionist civilization will get in a fight eventually, and it will lose. Even if it doesn't get defeated so utterly that it is forced to stop expanding, eventually it will just encounter another civilization that will stop it from expanding.
The only scenario where continuous expansion is possible without FTL travel is if one of the very earliest civilizations in the universe has an inexplicable drive to expand and does so fast enough that no other civilization can arise fast enough to snuff out all possible competing civilizations in their infancy. That we have reached this point in our technological advancement long before a non-FTL civilization could expand throughout the visible universe strongly suggests such a scenario is impossible.
[0] Some people may feel inclined to bring up Von Neumann probes - craft which travel to other star systems, repilicate themselves several times over, and then launch more such probes to more solar systems, thus allowing for exponential growth. This technology doesn't actually make expansion any faster though. Building a probe at A, sending it to B, where it builds a second probe, and then sending that to C will always be slower than building two probes at A and sending one each to B and C directly. There is also no benefit to longevity - building a new probe is equivalent to replacing every component of the original.
I wouldn't be so sure. It is a question of philosophy really, but there is the argument to be made that a change in form correlates with a change in function, even to the point of changing what a mind is. Suppose humans did that, changed our bodies to survive different environments rather than change environments. At some degree of modification these changed creatures would no longer be human, even in behavior, not just appearance. Where is that degree? And then, what's the point? What is our goal, to spread earth's version of life, it's biosphere? Or to spread minds and create more? Or to spread humanity? If it's the last one, it makes no sense to extensively modify our bodies, because you wouldn't be spreading humanity, just life, or just minds, at which point why not just send tardigrades or awesome computers into space?
And probably getting smaller every year. We don't have as many giant multi-megawatt radio transmitters as we used to. Quite conceivably it could be ~zero in a few decades, as everything goes fibre and cellular.
It takes a lot of power (or a highly directional antenna) to send a detectable signal detectable light years away. The only unintentional signals we generate are high power weather and military radar. Those are very tight beams that sweep the sky. Any interstellar eavesdropper would need to have the beam sweep over them to detect it. Even then it would be a transient signal with no guarantee of repetition since everything is it motion.
It would be like us being a mile apart in the blackest of night and you swinging a laser pointer around. Even if I'm looking specifically for you and have a general idea where you are the odds are vanishingly small your laser pointer will happen to be visible to me. You'd have to be specifically pointing it at me to even have a hope of me seeing it.
We could blast radio waves with ABBA songs into space to find whether there are other Swedish-speaking civilizations, or whether we are alone in the Universe. We don't because it's silly to think of the Swedish language as a necessary step for "advanced life".
Why do we think that human-like intelligence is special?
It's only futile to blast ABBA songs (or other human-like signals) into space if we think human-like intelligence is special.
It's precisely because we believe human-like intelligence is _not_ special that blasting (or listening for) space signals makes any sense. The assumption is that other civilizations will converge on some of the same technology that we've developed and recognize a patterned signal when they see one.
Why would anyone think that?
No other species in the history of the Earth has the ability to create human languages. Nobody outside the tiny group of 0.1% of humanity can speak Swedish. No single rock we've observed outside our planet can even understand the concept of a word like "Läderlappen" or "Knullruffs".
Those 10 million people are alone in the Universe as developers and speakers of Swedish just like these 7.9 billion people are alone in the Universe as developers and users of human-like intelligence.
Blasting signals into space is the same as singing ABBA songs really loud: maybe a sci-fi civilization of Klingons who speak a Swedish-like language could understand it, but in our Universe there's no chance that some extraterrestrial thing will converge on the same languages or technologies as we did.
In other words, we look for aliens equipped with radio telescopes, because they are the only kind we can hope to find.
The choice of language follows from that. To have technology at the level of radio telescopes, you need to understand physics at mid-20th century level (or higher). To understand physics at that level, you need math at the level of calculus and differential equations.
So we look for, and sometimes send, messages which start with simple mathematical relations and then build up to physical quantities.
I also disagree that "civilization" is something that could be applied to non-human things and not an arbitrary property of humanity like "Swedish speaker".
The other issue is that it’s not clear how long technological civilizations last. We might be close to exhausting our own planet just 150 years after the invention of radio. Maybe technological civilizations bloom in the dark like beautiful flowers, then burn out quickly before they can spread to other systems.
First of all, we are talking about predicting the actions of superintelligent aliens. We aren't talking about slime molds or a bacterial infection, but beings with more intelligence than us, like orders of magnitude more complicated reasoning processes. They are effectively unpredictable, because if they weren't, wouldn't we be just as smart as they are? That level of intelligence comes with new levels of reflectiveness that are frankly not accessible to our weak brains. Like, maybe after reaching the next level of enlightenment, they decide that expansion throughout the universe like a worm is not actually what they want or that is what is good for the universe? Maybe they decide to rather study the universe and not interfere, the way biologists study, say, apes, without wanting to disrupt their natural behavior with their presence? Or maybe superintelligent beings find a way out of our universe, and pass into another dimension (cyberspace? black holes? disappearing through quantum foam? heaven?). Or maybe something else insane happens, like being superintelligent inevitably makes you completely terrified of everything, because you realize how powerful other aliens are and your calculations unequivocally show it's safer to stay at home and fart around doing the super-intelligent analog of baking chocolate-chip cookies? Not being superintelligent, we are like ants trying to contemplate human civilization. We have no context or experience, and we simply don't have the mental capacity to even imagine what we don't know.
Second, these probabilistic models are so fundamentally stupid. It's impossible for us to reliably estimate the probability of any event that's happened only once (without reasoning about the process that gave rise to that event), as we cannot estimate posterior probabilities without lots of samples. And humans on Earth have a massive chain of single-occurrence events that all seem to be absurdly improbable. Besides that, and perhaps even because of that, it's not even a foregone conclusion that our universe even selects from the middle of the distribution (i.e. is not biased). We could perfectly estimate the shape of a probability curve and yet live in a universe that stubbornly selects from the end of the distribution, all the time. All of our math could be totally right, but crazy shit just keeps happening.
Third, the anthropic principle is a total bitch. It means that we will never be able to estimate probabilities of events that were required to create us, because no matter how improbable they were, if they didn't happen, we're not even here to argue about it. If there are infinite universes (a multiverse, see Tegmark), then forget this whole mathematical sophistry, because then there is no need to live in some "average" universe; we can easily live in some stupidly improbably snowflake universe that has the 90 trillion improbable things that make apes possible; infinity doesn't care.
Coming to conclusions/guesses requires starting with some assumptions about about how the universe works. It's important not to lose sight of those assumptions and very important to have a discussion about how likely each assumption is to be true. So to the extent that anyone is saying "this is definitely how the universe is", I wholeheartedly agree with you.
However, it feels like you're being a little too epistemically nihilistic here. This kind of speculative work always starts without confirmation or any particular reason to believe it beyond how well it matches the curve it was fit to.
To quibble with a particular, this work doesn't attempt to predict the actions of super-intelligences, it's not making the claim that most civilizations will be "grabby", it's making predictions about what will happen under the assumption that some subpopulation of them decides to become grabby.
Here's what I mean. What makes the lights on your router blink? Usually, it's packets going in and out. At a coarse level, if your computer is doing something on the internet, the lights are gonna be blinking. But now increase the resolution, from seconds, to milliseconds, to microseconds, to nanoseconds. At a nanosecond level, whether the LED is on or off depends on whether a packet is going over the wire right this nanosecond. Whether a packet is earlier or later by a nanosecond is influenced by a bazillion variables: the router's internal state, its own operating system's scheduling, whether the devices connected to it are sending packets at it, dragging in their state, their scheduling, their programs, packet queues, etc. Gigabytes of state, changing nano-second to nano-second. Oh, and it's connected to the internet. When does the internet decide to send a packet to this router? If those are faster or slower by a nanosecond, it could be due the state along the entire path, all of which are servicing packets from all over the place, decided upon by super-complex distributed systems--datacenters full of them. So even the blinking of a router LED is connected to a supremely complex causality tangle. To understand the blinking nano-second to nano-second, you basically have to replicate the details of the entire internet. So, if I were to ask you instead to predict what will happen tomorrow at 3:33am--will your router be blinking, let's say, fast or slow? Who knows. A DDoS might crop up because someone was mad at Amazon, or maybe your OS downloads a software update, or maybe you are up watching Netflix, or maybe the whole thing is down because nuclear war. It's progressed so far from a simple bell curve that probabilistic reasoning, I would argue, is useless. And that's just without the internet being "intelligent"! Now assume the internet knows this prediction game is afoot, and it gets to bet too. The whole thing goes off the rails.
No, we can't predict what aliens will do. This paper is a mathematical exercise that might apply to bacteria or video game characters, not interstellar civilizations.
To be fair, based on your description, assuming is is not completely random, you can still build a somewhat accurate model that would be able to somewhat accurately estimate when and how often the light will be blinking without having a full understanding on what exactly causes it.
That's my take, they wrote it better though. That section is short, straightforward, and worth reading.
SETI conceded many years ago that the evidence of a "Loud" alien species > a few Million years ago might be virtually undetectable today.
In particular, work like this makes assumptions about what it means to be "loud" which contain what amounts IMO to a profoundly inane belief that advanced civilizations would employ communications that are similar enough to our own that we could detect them, or, would leak energy in a fashion we could detect.
Both of these premises are deeply anthropocentric, in specific, they extrapolate from our current and 20th c. level technologies and understanding of physics, material science, etc., not even touching on philosophical matters like the dark forest hypothesis,
which are so myopic as to be comical.
Idle comment, sometime in the last year or so there was a detailed write up of a zero-day no-touch exploit for the iPhone, which included a nice tour through the wireless stacks and hacks Apple uses to do things like proximal device detection and networking.
What struck me at the time and continues to inform my opinion on these SETI questions is,
without the frame for understanding the why- and how- going on in the iPhone,
the scale of effort it would take a naive investigator to build a basic model of what was going on and why, is already at the threshold of human comprehension.
While in this specific case what's at issue is EMF using crudely comparable encoding schemes,
the point is simply that even knowing about various obvious ways of encoding binary information for transmission in a noisy environment,
the active signal(s) are already close to the edge of discernible from noise, especially complex but true noise.
I.e., even in the EMF domain, we're already for fungible consumer goods dealing with multiple frequency-hopping handshakes and sniffs and stochastic back-off and retry and error correction.
But there is no good reason to assume some other civilization at some other level of advancement would have any use for EMF. There are even with known technologies all sorts of exotic, more efficient, more targeted, ways of doing long-distance communication. Helically polarized lasers come to mind...
Anyway. I think the authors of these things need to be a lot more humble about their presumptions, or at minimum, spell them out plainly...
If that's the case, and we're early to the universe, it seems like the kind of data we should try to make sure survives beyond us.
While the Earth has hosted microbial life for about 3.7 billion years, it was only about 2.3 billion years ago (the GOE) that free oxygen started to accumulate in the ocean and atmosphere, making complex multicellular life possible.
So we’re probably in more like the last 20% or 25% of the habitable period.