The problem with 'unknown unknowns' is that you can come to whatever conclusion you want, and it's perfectly logical either way.
The 'Dark Forest' model suggests that we should be as quiet and inconspicuous as possible.
But I could also propose what I am calling the 'lumberjack model'. Suppose a lumberjack wishes to cut down all of trees in the forest--but being a sympathetic lumberjack, he avoids felling any trees with a birds nest in them. In that case, the birds should actively be as loud as possible and make their presence known to the lumberjack.
Both models are perfectly logical, but come to opposite conclusions--we simply have no idea whether aliens are more like the predators of the dark forest or the lumberjack.
As for Hanson's theory, it might be that the universe is one giant winner-takes-all system. But I suspect one could also come up with an equally valid theory that concludes something else--and we have no way to discern one over the other.
It's fun to speculate, I am just encouraging extreme caution I'm thinking we have any clue about any of this stuff.
As time goes on, and we find no evidence of aliens, the dark forest model is more and more likely vs. the kindly lumberjack model. In the kindly lumberjack model, we're more likely to detect other civilizations.
The assumptions of the drake equation are not relevant. The idea that we are the only intelligent life in the visible universe begs for an explaination. That it seems like we could colonize the galaxy in 0.1% the age of the universe makes it even more odd.
What time periods are long enough to warrant significant changes to how likely we think it is that the Dark Forest Model corresponds to reality? I would have thought very long, given the scale of astronomical observations.
>> I would have thought very long, given the scale of astronomical observations.
Or not. The great thing about astronomical observations is that they can scan across millions of years in a few seconds. We look at thousands of other galaxies, some old and some ancient, but do not see massive extraterrestrial civilizations doing big things. That is pretty strong evidence that there aren't any lumberjacks chopping down stars for firewood.
The contention is more nuanced and forceful. It's not just that we can do a survey, and are doing them;
it's that our notions of what would be useful to look for are to significant extent conditioned on our own level of technology.
There are axioms, for sure; but we are also axiomatically limited in our imagination to that which we have had insight into with so far.
Our surveys to date have focused almost exclusively on the presumption that an advanced civilization would emit (intentionally or as a byproduct) RF in a manner we can detect in the bands it is convenient for us to examine, and focus on from reasonable first principles.
But there are as many arbitrary assumptions or allowances for our convenience or technology in our surveys as there are motivated ones. Arguably more. (I would so argue.)
Not long ago I read that fascinating blow by blow of the zero-day demonstration of using Apple device discovery exploits to own iPhones, so long as you could get close to them.
As interesting to me as the actual exploit mechanics, was the patient walk through of the state of the art of frequency hopping band-sharing error-and-conflict-tolerant protocols matter of factly surrounding in my in my house.
Were I a HAM operator patiently looking for CQ, I might well miss the massive Zoom party going on on the local Wifi. It would be "noise."
I am not making a specific argument, just saying: our own technology continues to advance so quickly at our own time scale,
that the presumption that the universe we can see is "dark" is IMO not just naive but willfully so.
There is much in basic physics we still are struggling with and/or have no plausible model for yet.
So long as that is the case, we don't even know if we're in a forest, let along a dark one.
>> exclusively on the presumption that an advanced civilization would emit (intentionally or as a byproduct) RF in a manner we can detect
No. That is radio SETI. The search for life also looks includes Dyson-SETI, the search for megastructures, or other technosignatures, which can have nothing to do with RF.
(1) A galaxy without any supernovas, with all the dangerous stars pushed out of the galactic disk -> the lumberjack scenario.
(2) A planet with gasses associated with industry -> technosignature.
(3) Unexplained planetary phenomena, starlight doing things that suggest large orbiting megastructures (Dyson sphere territory).
... and the list goes on. Radio telescope SETI is one very small corner in the search for other civilizations.
> We simply have no idea whether aliens are more like the predators of the dark forest or the lumberjack.
That is not entirely true, currently it is 1 to 0 for the dark forest theory, as we have at least one data point: Our selves (as to aliens, we are aliens), and you surely don't want to gain our attention.
Except that much of the world has culturally outgrown this kind of rape and pillage mindset. It's reasonable to assume that trend will continue as we enter the interstellar age.
Sorry but I think people from Iraq, Afghanistan, Yemen, Syria, South America until some 20 years ago and so on... disagree with you... at least for the pillaging part.
For the rape part you have what the UN been doing in Africa or central america.
Let's not forget the ethnic cleansing in China, similar cleansing of the Rohyinga in Burma, open slave markets in Libya, etc. etc.
Human nature hasn't hasn't changed, we just ran out of easy to settle real estate. And it's not cost effective to go after easily settled areas -- a couple of world wars showed how ugly that can get.
Once climate change starts changing things I'm sure we'll see yet more "colonization" and unpleasant behavior.
The bombing of innocents in those places, while tragic, is nowhere near the scale of the destruction of native populations that was happening a few centuries ago, and public outcry is also louder from the countries doing it. So the trend is in the right direction, wouldn't you agree?
A counter-argument I've read to the dark forest theory is that:
* spectroscopic analysis can show that our atmosphere is oxygen-rich, and this can be detected from a range of many light-years away
* oxygen-rich atmospheres probably indicate life
* we've had an oxygen-rich atmosphere for hundreds of millions of years
So, yes, radio wave emissions have only been going on for 100 years, but we've looked like a life-bearing planet for 100s of millions of years and nobody's taken a successful extinction shot at us that we know of.
Is it though? We only have one example of "life" and that is an oxygen based form. Supposing all forms of life are similar is something I consider unproven.
It might be more accurate to say an "unusual" planetary chemistry is indicative of an unusual process, which might include life. But then the question is: How many planets are there with unusual chemistry? I think we are far from observing this - the many planets we now suppose to exist are only just being discovered, starting with the largest, the hottest, and the nearest.
> nobody's taken a successful extinction shot at us that we know of.
Are you sure? Someone's been chucking bloody big rocks at us for millions of years, on and off. Some of which appear to have caused some pretty spectacular extinctions.
Maybe the issue is that we think the aliens fly around in saucers when, in fact, they are just playing a gigantic game of pinball.
The precision it would take to launch an unguided rock from one solar system to another and hit a particular target makes that seem unlikely. Just imagine how many different gravitational forces you’d have to account for over such a long period of time! Depending on how fast you can throw it, you probably have to account for gravitational masses that don’t yet exist or would change significantly before your rock got close. It would be truly impressive. But any civilization worth bombarding like that would also probably be able to protect against that threat model, right? It seems that detection and mitigation are at least theoretically within our grasp already (I’m going to cite the movie Armageddon here), and we pose absolutely zero threat to a civilization in a distant solar system.
But both of those models start from the assumption that it is possible for an alien civilization to expand beyond its home star in the first place. But if you try to draw parallels to known knowns, one could convincingly argue that such an assumption is not a given. For example, humans are undoubtedly a technologically dominant species on Earth, yet our growth model is not to expand to every corner of the planet in an indiscriminate fashion: throughout history, humans tended to settle (and re-settle) the same areas that were most conducive to civilization, while remote areas remain for the most part remote.
It really isn't a stretch to posit that an alien form with liquid-methane-based chemistry (instead of water-based) would want to stay far far away from places like Earth, just like we wouldn't like to sunbathe in Mercury. And the boring but most likely occam's razor of alien civilizations is that it isn't actually physically possible for a civilization to leave their home star.
Given the long-term span of evolutionary biology, and the short-span of human civilisation, example based on humanity are short-sighted. Many would assume "post-human" existence that escape the trappings of biology, e.g. even now we have a non-biological presence on Mars, in the form of a robotic lander; perhaps in a couple 1000 more years humans can settle wherever we can build functioning machinery capable of supporting AI.
In these "post-singularity" times it's hard to speculate.
Robotics last far less than humans do though. Last year there were literal forest fires in CA because we can't figure out how to hang power cables without succumbing to corrosion from a measly 100 years span. If we want to make arguments about longevity, we could maybe look at microorganisms, but my understanding is they are similar to us in the sense that they thrive where it's conducive for any given strain to thrive, but die where it's not.
Everything needs maintenance in some form, whether organic or not. The only limitation for inorganics right now is an incapability of self-maintenance. We do it through many ways in our biology: nutrients from diet, exercise (on purpose or just day-to-day activities) for muscles & cardiovascular health. On top of that humanity added its own methods, namely everything done in healthcare & pharmaceuticals.
> because we can't figure out how to hang power cables without..
I think it's unfair to cherry-pick one task attempted by a cost-aware electricity company, that didn't involve the majority of humanity, and judge humanity on that basis. The nations best and brightest where not called upon to hang power cables.
I don't think I'm being particularly uncharitable. Look at the Opportunity Mars rover. It died after a record breaking... 15 years. And that is arguably one of the most sophisticated robotics projects humanity has ever deployed. The IIS has been around for only like a quarter of a century and despite being constantly maintained by highly trained astronauts, it already had air leak issues. And FWIW, power line maintenance is much closer to average humanity than NASA is, and also quite a fundamental piece of technology that you'd think we as a species would have figured out by now.
I just don't see a post-human future that is based on silicon: the manufacturing process is far too complex and poisonous to be viable as a self-replicating system and it doesn't last long either. I don't see a biological post-human civilization being feasible either: we've all but depleted all easily accessible natural resources, so any new civilization would have an uphill climb to surpass our technology.
People talk about Dyson spheres but for some reason no one mentions that space debris will puncture every material known to humankind because it's just flying so damn fast. Seems like a fairly obvious and fundamental physics issue IMHO; not exactly something that one can just wave away with theoretical future technology.
Maybe you know something I don't, but as far as I'm concerned, space colonization feels more like wishful thinking than something that could actually realistically happen.
I'm afraid I'm unable to judge how state-of-the-art Mars rover is, but I'll point out public-sector investment in space projects is much lower than it used to be, such that it was possible for SpaceX to eat its lunch - beyond that I have no idea.
> also quite a fundamental piece of technology
I don't think long-term cable maintenance is considered important; whether a technology exists, and whether it was provided (at cost) is different. In most cases the electricity companies where obligated to provide maintenance to small communities, without profit, so did it on a least effort basis.
> I just don't see a post-human future that is based on silicon: the manufacturing process is far too complex and poisonous to be viable as a self-replicating system
I didn't say anything about self-replication; but AI controlled hardware could be self-replicating/sustaining in exactly the way human society is. In the meanwhile, If a sufficiently flexible robot can be remotely controlled by human operators, what stops multiple robots maintaining each other?
Who knows, maybe sufficiently advanced civilizations eventually discover some orthogonal means of existence far superior and “real” compared to our current universe, and we’re just too stupid to see it.
Edit: Now that I think of it, I’m pretty sure that’s close to the plot of a Neal Stephenson book I’ve read.
I'm still not very convinced any civilization will actually expand significantly beyond one solar system.
It's not just really hard, you'd need really good reasons for expanding that long (as opposed to just exploring). As Humanity, we're not even sure about increasing our own population size forever.
I think we have two options: to expand to outer space, or to expand to virtual reality and eventually become digital beings. I'm not sure if these options are mutually exclusive, but for the curious mind the digital option would probably be more rewarding with less effort. We even might gradually lose our capability to interact with physical reality, which might be the great filter.
In digital form, it's much easier to travel to outer space though. We just need to send transceiver probes in advance. If we want to manifest physically, we just have to print robotic bodies in the destination.
Edit: I just realized that even if we're in digital form, we have to fight for physical energy and resources, assuming that we want to keep expanding the digital realm and the capacity of our consciousness. So, in some form we have to expand physically.
Maybe your tech allows self repairing Infinite Fun Space simulators which are also impossible to destroy, as they are inside stars, inside black holes or made of matter that doesn't interact with anything else.
Well, its not so much a direct part of The Baroque Cycle as a continuation using descendants of the main characters and a lot of shared themes - a bit like Cryptonomicon.
However, The Baroque Cycle does have some unusual minor elements such as 'magical' gold and an important character, Enoch Root, who appears to me immortal and who turns up in 17th, 18th, 20th and 21st centuries.
Fall gives an explanation of what is going on that I really liked.
There’s no reason to believe that humans living as “digital beings” will ever be possible. We don’t even know what consciousness is yet, never mind how to replicate it in a non-human substrate.
Most living humans will still argue that consciousness roughly equates to a soul. Leave that nonsense aside, and you’re still left with the mind-body problem: are those two things the same or different? If mind and body are the same — that is, if the experience of being a conscious human is emergent and/or dependent upon a human body — digital uploads are just copies of ephemeral state. Imagine a hell full of James T Kirk replicas, each regretting the time he stepped into a transporter and died, allowing a copy of him to be made elsewhere.
If mind and body are different, you’re picking up the Cartesian problem — how do they influence each other at all? What is the mind made of that it can simultaneously affect the body, yet somehow exist separately from it?
Neal Stephenson published “Fall” last year which treats this as a purely technical problem. Once our scanning resolution is good enough, he supposes, we’ll be able to create perfect digital replicas of brains. That’s tripe, of course. Human consciousness is dependent on much more than our brains. In fact, we have special words for how consciousness presents when disconnected from bodily sensation, words like “sleep” and “coma.” Sensory deprivation chambers isolate us from some of the sensations outside our bodies, but leave all internal sensations intact.
These external and internal sensations make us who we are. For instance, we cannot emulate consciousness without first emulating the billions of gut bacteria, across thousands of distinct species, that affect the physical rhythms of our bodies. Even quadriplegic’s moods and consciousnesses are influenced by their gut bacteria.
How much of the universe do you need to simulate in order to accurately simulate one human being? All of it, it turns out. And even then, there’s no reason to believe that human will be or feel the same as the meat substrate from which it was copied. The whole affair is nonsense.
Scanning sure, that’s a separate consciousness or a copy, but what if you replaced one neuron at a time with a digital/electrical component? Wouldn’t there be a point, around halfway, that you would be more robot than human? And so you can become totally digital if you accept that losing one neuron wouldn’t be enough to end your current stream of consciousness?
Personal identity philosophy is full of examples like this: swapping brains, swapping half brains, swapping cells one at a time. It’s an interesting thought exercise.
I don’t have a complete answer, but a few thoughts:
First, there’s no reason to believe we’ll ever be able to replicate a neuron with non-meat technology. Nanomachines may be able to do this. Are they going to age and die as well, like real neurons?
Second, replacing one neuron at a time looks hard as well. Best case is perhaps a self-replicating nanomachine that chugs through the brain, effectively eating neurons and building new ones. This process is going to change the brain, since it has to be carried out in constant time. How will it change the brain? Who knows?
Third, it’s not just neurons. You’d need to replicate every cell in, and on, a human body. Including, again, the different species of fungus that live exclusively in our toenails.
Fourth, how will this new 100%-technical human interact with its environment? Current thinking is that some auto-immune diseases are triggered by a insufficient challenge to young immune systems, effectively by an environment that’s too clean. Should we emulate this as well?
So pretty quickly I think it’s turns out that we’re not emulating humans, we’re creating new things that are somewhat human and somewhat digital. How will this entity act over the long term?
Ian McDonald wrote, “there are infinite ways of being human.” Perhaps we need to expand our definitions.
> Third, it’s not just neurons. You’d need to replicate every cell in, and on, a human body. Including, again, the different species of fungus that live exclusively in our toenails.
Do you?
Don’t get me wrong, the chemical environment of the brain, and the wider body, can alter states of consciousness — I recall stories about people whose gut bacteria produces alcohol and permanently fail any blood alcohol tests as a consequence — but if you know what those chemicals are, do you really need to replicate the fungi making them?
> there’s no reason to believe we’ll ever be able to replicate a neuron with non-meat technology
Can you back this up with anything? In ignorance, I could just as well state: "there’s no reason to believe we won't ever be able to replicate a neuron.."
I suspect you are being pedantic with the definition of neuron, i.e. not allowing for simulations that contribute the same/similar net effect but fail to account for every last irrelevant molecule. The fact that you say the whole body needs to be replicated is what makes me suspect this:
> Including, again, the different species of fungus that live exclusively in our toenails
If this where true, elimination all the fungus in my toenails would make me: inhuman or non-conscious?
If it would simply make me (chaos-butterfly style) a different, but still human & conscious version of myself, then I'm not sure why it's necessary.
I think the definition of human can be stretched, and obviously once your body is replaced digitally you have altered the definition. But I think you have chosen an overly strict definition in your "every cell" maxim.
The electronic neuron would have to behave just like a legit neuron, and would have to be installable without damaging the legit neurons.
Even if this is philosophically possible, that doesn't suggest it is inventible. How do you model and replace a neuron without tearing up and killing the host organism?
I think this argument is based on the false dichotomy of "The mind & body are either different or the same!".
This denies things being similar, or multi-dimensional. Apply this same reasoning to hardware/software for example:
"What is software code made of that it can simultaneously affect the physical hardware, yet somehow exist separately from it?"
the mind, and software, are data, or information - and data can be replicated on multiple mediums. This data / medium distinction is no more or less perplexing. The "OK" hand-gesture can represent something in physical form, while the physical hand is distinct from the symbolic message it represents - if you want to get philosophical about symbology and representation I don't think there is a special case to be made for the mind.
> Human consciousness is dependent on much more than our brains
How can you support this statement when you first lead with "We don’t even know what consciousness is [yet]"?
We have words for "god", "magic" and "spirits" too, and don't know what those are either; isn't it possible none of them exist?
> we cannot emulate consciousness without first emulating the billions of gut bacteria
Only is consciousness specifically depends on this aspect.
It's like saying "The setting sun also affect our mood, so that must be emulated too!". That's not true though - It's be possible to emulate a human mind, without exactly reproducing the same personality and emotional profile of a modern human being. Simulating human environments and/or experience to feed a simulation data is a bigger project than replicating a mind. If you are simulating every detail of human existence the question is what you are trying to achieve; post-human AI being don't need to be anything like modern humans phycological; and I doubt the contributions to mood of gut bacteria are considered fundamental in that - and I've yet to hear a modern human consider the diet in questions of consciousness.
For example, We live, and eat, very differently to our ancestors - Does that make us any less human, or conscious?
I don't think so, and as such don't agree that: "All of it, it turns out".
> Neal Stephenson published “Fall” last year which treats this as a purely technical problem. Once our scanning resolution is good enough, he supposes, we’ll be able to create perfect digital replicas of brains
That's...not at all accurate.
> How much of the universe do you need to simulate in order to accurately simulate one human being? All of it, it turns out. And even then, there’s no reason to believe that human will be or feel the same as the meat substrate from which it was copied.
That's actually much closer to the premise of Fall than your summary was.
Tell me how. My recollection is that Dodge was scanned from a frozen brain. Later in the book, folks were full-body-scanned.
And conceding that we need to simulate a full digital universe in order to simulate one person gives away the argument entirely — there’s still no coherent way to say that it’s the same person, a digital afterlife of the same soul. Stephenson blithely writes as if this is true.
You claim: “Once our scanning resolution is good enough, he supposes, we’ll be able to create perfect digital replicas of brains”
None of the scanned replicas in Fall is perfect. They are functional in that they have consciousness, and connected to the original by some fuzzy, vague, and very much incomplete transference of memory and personality, but that's notably imperfect even for the focal information where people most knowledgeable about the process are deliberately trying to carry key information and plans across the transition. That is implicitly (though it is hard to tell how much since neither is a viewpoint character, and the original was progressively becoming insane before the transition) somewhat less the case for Elmo Shepherd/El—the former of which spent enormous time and astronomical resources to achieve that—than anyone else, sure, but there is no indication of anything even vaguely approximating a “perfect digital replica”.
> there’s still no coherent way to say that it’s the same person, a digital afterlife of the same soul. Stephenson blithely writes as if this is true.
No, he writes as though the society of the not-yet-uploaded in the book comes to accept it as tru-ish and those of the imperfect-replicas-who-come-to-understand-their-nature view it as also (but, at least in my reading, somewhat less than the preceding) somewhat tru-ish.
But even the characters in the book, on either side, don't seem to accept it as unqualifiedly true in general with the possible, again, exception of Elmo Shepherd/El. Who is a, or both of whom are (depending on your perspective on continuity of identity) unbalanced megalomaniac(s).
(Even before things get dominated by the afterlife simulation, the book already has a strong focus on the socially-constructed nature of perceived identity and perceived nature of reality.)
Forgive me, but this sounds like a criticism — is it? Because last I checked that novel was fiction, and that is what good authors do. It’s not like I’d criticise Diane Duane for writing Trek books as if Vulcans were real; if anything its kinda weird when shows like Trek break the fourth wall, which they avoided even in the two episodes which used the “the show is a fiction invented by one of the characters” trope.
Wasn't one of the points in Fall; or, Dodge in Hell that an isolated mind was pretty much impossible and that he had to build an environment at the same time that has mind was awakening?
Yes, I actually love that awakening story. It’s been done in fiction before (e.g., “Cybernetic Samurai,” by Victor Milan) but Stephenson rendered it vividly.
Even if we accept this on its face as possible, we still have no reason to believe that the digital Dodge will act the same way as the formerly-meat Dodge. Developmental trauma is a real thing. How did that experience of awakening change Dodge? If it changed him at all he’s no longer the same Dodge; if it didn’t change him, then he’s just an immutable copy.
And then if we figure out some convoluted way to claim that Didi-Dodge will act/present the same as formerly-meat-Dodge, they’re not in any way the same person. Meat-Dodge is still dead, he just has a very lifelike digital replica.
About your edit: That is the plot of the excellent early access game "Dyson Sphere Project".
In the game backstory humanity became entirely digital, but found out AFTER that, the energy requeriments are staggering, so they send the player in a robot body to fix the energy issue. (you start building solar panels and thermoelectric powerplants and whatnot until you can build a dyson swarm and finally a dyson sphere).
As long as you're not interacting with the outside world, what does the computational speed of your substrate matter? Your in-universe clock runs at the same speed you do.
May or may not be enough, we’ll only find out by doing it. The speed difference between synapses firing vs transistors firing is about the same as speed difference between a wolf and the hill the wolf is standing on. Coincidentally this is also the size difference.
the 'digital form' computers could be on a spaceship that is programmed to try to guarantee it always has enough power, acquired via stars, to power the computers in which the non stop orgasm universe is running
Simple evolution. The fraction of the species that decides "yeah, this is enough" stays behind. The fraction that does not keeps developing and exploring and eventually just straight-up outpopulates the fraction that didn't even if they never actively have a conflict with the "satisfied" group... which is a pretty big "if".
This is actually exactly what happened with modern humans and neanderthals. Neanderthals never ventured outside their native region in Europe. Modern humans spread to every corner of the globe, going so far as paddling a boat to Australia.
Its in our genes to be curios explorers, and that has helped the species survive.
Expected famine and drought would likely work equally well. There's a lot of small communities that continue to exist purely because the government keeps the famine and drought part from happening. I'm thinking old mining and factory towns build around a single employer, which since has closed up shop.
Counter argument: the evolutionary pressure that makes a species smart enough to colonize a planet (say, earth) doesn't make them smart enough to colonize space beyond their solar system.
Since there is no evolutionary pressure to increase intelligence further, the species does not leave the planet.
> In just 3-5 generations, the people who will own the Earth are those in cultures or subcultures that have lots of children even in the presence of birth control
The thing about pseudo-science is it often borrows (and distorts) real scientific concepts to masquerade as such; the existence of homeopathy doesn't discredit conventional medicine.
To be fair, he wasn't talking about eugenics directly, but he's invoking a lot of assumptions and sentiments about "certain cultures" outproducing others.
You assume that birth rate differences between cultures are stable, which they have never been. But for sure it's a racist trope to somehow assume "certain cultures" reproduce like bunnies just because whatever, and "replace us within 3-5 generations". Neither the data nor the math makes sense on this.
It's not even genetic variation. Of course there could be genetic variation to reproductive success, but this variation hasn't magically and neatly assorted itself into nationalities or religions in the past few centuries for our convenience.
Fact is that the absence of Human suffering, side effects of wealth and freedom, seem to decrease birth rates overall. No religious fanaticism will overcome this mechanism long enough to matter.
The "cultures" need have nothing to do with race or religion or anything else. They simply need to reproduce incrementally more. That can be the distinction, all on its own.
Remember, evolution is not generally a game of "One day, this horse was born with a mutation that enabled it to use oxygen seven times more efficiently than its brothers." It's often a game of very small incremental differences slowly outcompeting the competition slowly over many generations.
A 2.1 birth rate will outcompete a 1.9 birth rate really quite quickly. It doesn't take much difference.
This is just standard evolutionary math, not some crazy conspiracy theory.
It may help everyone involved to remember we aren't really talking about humans. It is a a bit of a crazy idea to assume that every species in the universe will all 100% experience the same effects humanity happens to where as they become prosperous, they tend to have fewer children.
In fact, I've seriously floated that as one of the possible reasons why humanity may actually survive where many of our competition can't. If you consider something like an insect-like species, they may not even be able to get this far without choking out their planet because they may be quite unsuited to "reproducing less in the face of more resources". Human babies are very expensive; it is not at all clear that this will be a universal among intelligent species.
I stripped out the comments about humans since it is distracting people from my main point.
> It may help everyone involved to remember we aren't really talking about humans. It is a a bit of a crazy idea to assume that every species in the universe will all 100% experience the same effects humanity happens to where as they become prosperous, they tend to have fewer children.
It's really not much of a stretch; K strategists generally beat out r strategists in relatively stable conditions, and both intelligence and, with intelligence, increasing technology and prosperity make a wider array of unstable natural conditions more like stable conditions from an evolutionary standpoint through adaptability.
Having more offspring is a trade-off against investing more in each offspring.
A lot of entertaining fiction springs up around premises where things which are fundamentally related are instead treated as orthogonal, so you have spacefaring aliens that want to compete with us for for earthlike planets but are structured like insects despite being human-sized, intelligent, technology advanced, r strategists, but...there's very good reasons that many parts of that are implausible.
Your "standard evolutionary math" still assumes relative birth rate differences as they are right now will stay the same into the future. They aren't stable right now and haven't ever been. A foolish assumption, but useful for certain world views.
And as those relative differences change and even invert in some cases, there really is no case to make for the idea that this supposed evolutionary effect could reverse what we are actually seeing in the real data.
'Your "standard evolutionary math" still assumes relative birth rate differences as they are right now will stay the same into the future.'
I have no idea what you are talking about. No such stability is required. No such stability exists in nature, yet evolution persists, right? The completely standard predator-prey recursive relationship intrinsically involves highly variable (successful) reproductive rates in a constantly oscillating relationship, but I don't hear anyone suggest that disproves evolution.
To be honest, if either of us are assuming constant situations that never change forever into the future, it really seems to be you. My entire point is based on variances. I'm arguing against the proposition that no intelligent species will ever spread across the universe because early 21st century humanity in the first world seems to not particularly be interested in it today.
Again, the discussion here is integrated across all possible intelligent species, not "humanity". It only takes one species to uncontrollably reproduce to spread across the cosmos. Science fiction is replete with possible such species. Does the HN gestalt not frequently remind people that aliens can be actually, you know, alien? Not just humans with funny foreheads?
Even Elon Musk might quibble with the idea that nobody in the first world in the 21st century wants to spread across the stars. If Mars were to build a self-sustaining habitat (which I define as a habitat able to build another equally-self-sustaining habitat), it doesn't matter whether there's 12 billion people on Earth uninterested in spreading out into the solar system, if Mars starts building and growing and spreading further. It only takes a few. It would then not further matter if they build a self-sustaining asteroid-based civilization if all the people on Mars decide they've got it made, and nobody ever again leaves Mars. I say the argument that 0.0000000000000000000000% of a species ever wants to spread out into the stars once they have the capacity, just because we happen to live in a couple of decades where most people (not even all, just most) wouldn't be interested in it is not a sensible one. It's parochial even on human terms; it's beyond parochial across the set of all possible intelligent beings.
Of course a difference in relative reproductive rates needs to be stable for the underlying causes to dominate and in turn affect reproductive rates. That's how evolution works. However, that's not how Human birth rates in different countries and communities work, today.
> I'm still not very convinced any civilization will actually expand significantly beyond one solar system.
I'm fine with the idea of a species -- or whatever definition you want to use here -- expanding beyond one solar system. But without at least faster-than-light communication, I don't think it would be possible to maintain a cohesive civilization at that scale. And without faster-than-light travel, you're also going to have things like species rings developing.
> I'm still not very convinced any civilization will actually expand significantly beyond one solar system.
Whether a civilization expand beyond their solar system is entirely depending on if they develop the technology to do so in a relatively short time compare to their life span.
One good reason could be habitable planets. There may not be enough habitable planets left in the solar system.
Escaping one solar system with some amount of colonists is probably harder than developing the technology to not need whatever counts as "habitable planet" at the other end.
They'd use the new system's ressources for all sorts of things, least of which would be biological survival.
I think "remotely habitable" is key. Humans can barely colonize Antartica. There's zero self sufficiency there, and there seems to be zero appetite for anybody actually settling there. At most, you get adventurers who'll spent a few years there, living off the teat of some research institution, only for them to return with some good stories. Moon or Mars are much more hostile to our physicality and sensibilities than Antartica. Mars will attract some adventurers, maybe initially some utopians. After an initial period of excitement, there will be zero appetite to actually colonize something as unlivable, boring or ugly as Mars.
There are network effect to infrastructure, both in space and at the poles.
No-one wants to build habitats in either b/c there are large up-front costs to building initial infrastructure. once it's there, things may change.
That said, Necessity is the mother of invention; and right now we have no reason to spend resources on developing these environs as there are plenty of more desirable habitats (e.g, nice climate w/ stunning views and wildlife), and the current trend is wanting to live near other humans in high-density cities.
Let underground habitat tech develop a bit more (100% artificial lighting replicating daylight), and planetary populations, and hence competition increase, and there may be more enthusiasm for this stuff.
Humans colonized the Arctic before the modern era. We could probably have done it in Antarctica too, if there was a pre-modern way to get there gradually.
> there will be zero appetite...
I almost completely agree. There will be very close to zero appetite. Which, over time, results in a colony :)
You can say it's an opinion, but I think you'll find it's almost universally held.
Most people would enjoy romming Mars for a few days, some would enjoy it for a few months. I think only a select few would enjoy being there for longer than that unless it dramatically changed.
In a galaxy with millions of civilizations, it only takes one grabby species to result in colonization. So you don't have to be convinced that any given species will expand, just accept that some might.
Expansion is selected for in biological evolution, so it's fair to assume that most pre-civilization species are expanding on their planet. Perhaps some will have an epiphany and stop expanding as their society progresses, but you'd have to argue that that will almost surely happen to every species to refute grabbiness theory.
> So you don't have to be convinced that any given species will expand, just accept that some might.
You'd have to accept the other assumptions that the authors make as well. One is that the grabby species is capable of travelling at a significant fraction of lightspeed. Another factor is unlimited lifetime of civilisations.
> Expansion is selected for in biological evolution, so it's fair to assume that most pre-civilization species are expanding on their planet.
Hm. I'm not sure that biology is the right angle to approach this. There are plenty of examples in human history (and even today) where expansion was not at all favoured by civilisations and human communities.
Isolated tribes on islands and in rain forests are a counter-example, as well as isolationist phases of civilisations such as feudal Japan in the Edo period.
To me the model is basically just another hypothesis based on the Spherical Cow.
That still has nothing to do with Biology probably not being the right approach to use here.
Evolution doesn't know or care about space travel. It's separate concerns entirely. One is a function of the environment and adapting to it, the other requires a sapient species to create and apply technology, which - judging from current observation - is neither a common, nor obvious result of evolution.
Genes can change behavior when you get into space. But you have to bet that, with millions of species getting to that point, not a single one will get any further. I don't know how anyone can have that level of certainty about such speculative things.
> we're not even sure about increasing our own population size forever
World population is expected to peak at 10 billion at some point during this century, then decrease quite a bit.
The most similar planets we know about are hundreds of light years away, and if we somehow were able to reach them, we would have to overcome issues such as receiving massive amounts of radiation, having no water, etc., so it's reasonable to expect human population to stay below 10 billion for a long time.
If the factors that led to our current population slowdown are maintained over the coming centuries then eventually there'll be a time when population starts to go up again. Some personality traits like Agreeableness are both heritable and tend to cause people to have more kids. So the trend should reverse itself eventually.
Where can I read more about the "decrease quite a bit"? People have been predicting that for centuries (Malthus, etc.) and they've all been spectacularly wrong so far.
Yes. And with Mars, on a smaller scale, there is just about the same problem: Of course it is interesting and fascinating to explore it. Or go there once for the funsies.
Much harder to establish something that brings back more value than it took to bring it there.
Even just keeping Humans alive there will probably be a very expensive proposition for at least a century or more, before there is a solution to the apparent economic futility of colonizing Mars.
Bringing back stuff from another star? Forget it. The only reason to go there is to be there. Or even more precisely, you send your children/creations there for their children/creations to be there.
We don't know if it's really hard. If it is really hard, I'm tempted to agree with you. That is, if we don't find a mechanism for FTL there's very little to be gained.
I think FTL travel can't be useful unless FTL communication exists first. Otherwise you're just spending a lot of resources to seed competing civilizations.
FTL travel actually implies FTL communication, since you can send a traveller with a message. What I think you mean is that communication needs to be either really fast, or at least a lot faster than the travelling.
I don't think that's relevant. All you really need is a segment of the population that wants to go somewhere else, and trade and whatnot can still work well without a communication system that's faster than travelling. That's how the trans-atlantic trade system worked from about 1500-1700.
> What I think you mean is that communication needs to be either really fast, or at least a lot faster than the travelling.
Precisely. Messengers wouldn't cut it. Ancient empires always struggled to maintain control of their edge territories, because communication was too slow, even with messengers on horse.
Ancient empires also regularly spawned friendly or unfriendly colonies on their periphery, and regularly lost control of them. Space colonization doesn't have to be useful for earthlings for somone to bother attempting it.
All of that said, we're probably less equiped to colonize space than the chimpanzees in Africa are to build boats and sail to Brazil.
If interested in this kind of thing, I always recommend Issac Arthur. He describes the Fermi Paradox and related concepts 100x better than anyone else.
I believe he would say that there is no really good explanation to why we don't see other intelligent civilizations except that we are effectively the first (at least in our galaxy), and intelligent space-faring life is exceedingly rare. This is a similar conclusion to Robin Hanson here, but I think I think Issac Arthur does a better job of deeply explaining it. I think both would agree though.
Space is just so unimaginably huge that although I think aliens exist, I don't think it is likely that multi-solar system civilizations exist or there is a lot of organic life traveling between solar systems. The fastest man-made object is Helios 2 which went a little over 250,000 km/h https://en.wikipedia.org/wiki/Helios_(spacecraft) So if I did my math right, that's 0.02% of the speed of light. So we would have to go 50 times that fast to just be 1% of the speed of light. The nearest star is 4 light years away. So even at the speed of light it would take 4 years to get there.
So a civilization would have to develop some way of going faster than light to realistically go to other solar systems which, even if possible, would likely take unimaginable amounts of power.
Space is big, but Helios isn’t us trying to go as fast as possible, it’s going the speed it is because that’s a requirement of orbital dynamics.
If we really really wanted, nuclear options could get us to a few percent of c with current tech and no breakthroughs.
On the other hand, if someone builds a von Neumann probe that eats sunlight and Mercury (the planet), it could make a Dyson swarm in a human lifetime, and that would enable us to colonise most of our causal future light cone directly from Sol: https://youtu.be/zQTfuI-9jIo
Just speculation (I am not a physicist or astrobiologist), but this is my thinking also. If anything is traveling between the stars, it's either inorganic (an AI), or it has a natural lifespan several orders of magnitudes longer than humans. Without FTL travel, to conquer space you also have to conquer time.
Organic life is fragile and ill-suited for space travel, at least organic life as we know it. Perhaps the destiny of all sufficiently advanced organisms is either to die off or replace itself with AI.
Anyway, while I find it impossible to believe there's nothing out there, I find it nearly equally impossible to believe anything that's ever visited our rock resembled little green men.
I certainly like the idea of traveling at 1G better than living in a rotating ring-like spaceship. (On the other hand, in my imagination I keep seeing this huge sign at the end of a journey to another galaxy that took forty years saying “Nothing to see here, move along...”)
They wouldn't need FTL. Sufficiently[0] powerful rockets with a sufficiently dense fuel source could reach relativistic speeds, allowing the travelers to experience the journey in less time than the trip takes according to an outside observer.
For instance, accelerating at 1G toward our nearest neighboring star for half the distance, then slowing down for the other half, a traveler could arrive in 3.5 years instead of the "minimum" 4.3. Of course, from Earth's perspective it took 5.9 years, but that's not important. The effect is exponential, such that a trip to the center of the Milky Way, ~30kly, would only take 20yrs ship time (30,002yrs Earth time).
[0] "Sufficiently" in this case meaning "pretty ludicrously".
Humanity only ventured into space in the last few centuries, and Helios 2 is the best current effort, not a fundamental limit.
Also, the real obstacles are not physical speed limits, but the huge cost of getting materials into space. If we ever got enough material into space to provide a true, self-sustaining industry (i.e. non-terrestrial power and materials) then we'd see a space-building boom that could rapidly improve on space exploration.
The earth is relatively close to the sun, better use of solar wind: both the light and the plasma might help accelerate without the high energy/fuel costs, see: https://en.wikipedia.org/wiki/Magnetic_sail
>> So a civilization would have to develop some way of going faster than light to realistically go to other solar systems
That is a very human mindset. "Civilization" would include machine civilizations. For a machine, a few thousand years of transit time would be irrelevant given the advantages a new star system might offer.
The vast distances between solar systems means that in order for life to expand beyond our system, it must either be put dormant for decades of interstellar travel, or it must travel in a craft so fast that modern physics thinks it unlikely. Since there's little reason to suspect that c speed of light is not the speed limit, that leaves us with some sort of biological suspension of life forms until they reach their destination. This tech is still extremely nascent, but to me there is possibility in at least sending seeds, microbes, probes, and very small crafts to nearby stars.
Nevertheless, it seems likely that we will expand heavily within our own solar system before we ever reach another star. Proxima centauri is light years away, but mars, venus, the asteroids, and various rocky moons are within our grabby reach.
What if aliens live on a different timescale than us, such that blinking their (presumably proverbial) eyes takes centuries? The speed of light suddenly feels a lot faster!
And why would these life forms need to be biological? Do they need to have a limited lifespan? Could they send their consciousness in a droid? There seem to be options!
"What if aliens live on a different timescale than us, such that blinking their (presumably proverbial) eyes takes centuries? The speed of light suddenly feels a lot faster!"
I think it's reasonable to assume that natural selection wouldn't favor that timescale.
For one, cosmic catastrophies - and resulting extinction events - would be much more often from the perspective of a "slow motion" lifeform.
On the other hand, from the perspective of "super fast living" creatures the universe would appear as a much more peaceful and friendly place.
Re: your last point, that's something I find the most realistic; Von Neumann probes (https://en.wikipedia.org/wiki/Self-replicating_spacecraft), self-replicating robots that spread across the universe, possibly carrying traces of the civilization that once built them.
I'm not sure that's true. While you don't end up with lightspeed expansion, if you get to the point that you have the tech to live on an "iceball" by extracting the hydrogen and fusing it for energy, and can make the rest of what you need from raw atoms and energy, you can just sort of... keep expanding out into the oort cloud indefinitely, until after a while, you're not in the solar system anymore, and even more eventually, you're in another one. The more we learn the less empty interstellar space looks.
That's certainly slow expansion, but it would be an expansion that in relatively short order would greatly exceed the biomass and biodiversity of Earth's biosphere, until it would be quite absurd that the whole thing would simultaneously decide to just stop one day. It would be slow but as difficult to stop as the biosphere is today.
This does depend on some sort of practical fusion tech, though.
Remember though that as you approach the speed of light, relativity starts to kick in with your time "slowing down". In other words, the inverse relationship between speed and time could allow civilizations to expand faster than it would seem possible at "normal time" speeds. Complete conjecture on my part, just a fun thing to think about!
You're forgetting option 3, and IMHO the most likely option. We become a space native species that inhabit an armada of ships. Colonizing planets beyond mars will very much be a secondary, optional objective. I think in a millennia, the number of humans living in o'neil cylinders will far outnumber the humans living on planets.
This is the modern version of 1700s common wisdom: "A vehicle would have to be much too light to travel through the air. Otherwise it would need an unfathomable amount of energy. And if it tried to go too far up, it would enter the ether!"
Advancement seems to grow at exponential rates. Perhaps in a 1000 years we will not see c as an impediment.
The big bang only produced light elements and heavier elements were produced by nuclear fusion in stars. In particular, carbon and oxygen[1] would not have been abundant until the first generation of very hot, very large stars went supernova. Our own star is a third-generation star[2]; it is only 4-5 billion years old, forming ~10 billion years after the big bang, so our own solar system is fairly rich. Earlier solar systems would have been less rich, and this means life would have been far less likely to arise.
Also, 25% of lightspeed is fairly aggressive. Even 1% would require engineering and energy reserves way beyond anything we can realistically hope for, largely due to the tyranny of the relativistic rocket equation[1]. Note that if you want to stop, you have to carry your own fuel, which makes the problem quadratically worse. Proposals like Breakthrough Starshot[3] can hope for 10% largely because they will just do a flyby and don't have to carry fuel for braking at the destination. Similar projects[4] have used much more realistic velocities and discovered in doesn't really matter - it still takes less than 100 million years to completely colonize every star in the galaxy.
But this model doesn't solve or address the Fermi Paradox - where is everybody? It actually makes it worse. We might overlook or not be able to see a single populated solar system halfway across the galaxy, but a civilization that has expanded to fill every nook and cranny of the galaxy should be fairly easy to spot, no? Obvious, even. Yet there is no sign - not in our solar system, not in radio signals, not in Dyson spheres, nothing. On the other hand, every time we still down and make reasonable assumptions about how long it would take a species to colonize the galaxy, we usually find that it should have happened hundreds of times over, billions of years ago. So where is everybody?
Regarding your final paragraph, the Grabby Aliens model implies that we are within the Anthropic Shadow[1] of the event. E.g., the humanity that lives in the possible universe where the galaxy has already been eaten does not exist.
You are right, but very large stars have very short lifetimes, on the order of 10M years. So there would be areas of high concentrations of things further up the periodic table even in the first billion years. Keep in mind that while earth is rich in things like iron and other elements higher up the periodic table, that's far from the average for the solar system.
I think the colonization problem is mainly a human perspective, we can't get their in our lifetimes so it's impossible.
So it seems realistic to send a small probe to Proxima Centauri at 5-10% of the speed of light to get sensors much closer. We'd learn quite a bit getting even today's sensors 1M times closer as it zips by. Communication might be tricky, but say a 100 watt laser can beam to a decent portable telescope on a precise frequency even 0.01 light years apart. Just sent a new relay probe every year or so.
So in 50-100 years we'd know much more about the planetary system. Number of planets, size, orbits, chemical composition, asteroid belts, even some idea of weather, clouds, magnetic fields, and some idea of the likelihood of life, and the potential for hosting life. Google earth would get it's first planet outside the solar system ;-).
With that knowledge, and presumable some technology improvements we could send a large probe, even if it's slower say 0.5% of speed of light. While propulsion technology will likely improve (things like light sails, fission, fusion, antimatter, etc) maybe there's other ways to slow down, gas clouds, magnetic fields, chained gravitational assists, magnetic ram scoops, etc. Maybe it could allow for a few 100 kg in orbit around the most promising planet. Potentially autonomous manufacturing could turn some asteroids into mirrors, we could be used to help brake future probes. Said few 100 kg would also include improved sensors to tell us much more about the planets, increase our understanding of the presence of life, and the potential.
Some 100s of years into the future it seems likely that bio-engineered bacteria, fungus, molds, and similar could be used to seed life, make the atmosphere friendlier, and extract useful minerals/fuels. Future deliveries would leverage braking/fuel/materials at the far side to get more mass there more easily. Instead of building mirrors (relatively easy) they start building solar cells. Mining kicks increases in scale, etc. Extracting methane, oxygen, and aluminum would be a good start.
Bootstrapping the ecosystem (assuming there isn't one) starts with bacteria, mold, fungus, and similar on land and in the oceans.
At some point the mirrors, communications, and energy available starts being an appreciable fraction of earth and non-trivial size ships can get up to 5-10% of light on this end, and decelerate down to zero on the far side and sending humans (or at least human DNA) starts becoming feasible.
Say 1000 years from now, intelligence (human, semi-human, or artifical) on the far end starts communicating with earth at the speed of light. Does make one wonder what bandwidth you can get over 5 light years with say a small moon of mass to capture and redirect energy.
Are the Culture the good guys or the bad guys? I read Consider Phlebas first and felt such a whiplash moving into Player of Games or whatever the next one was. I want to like that series but I just can’t figure out if I’m rooting for bad guys or not.
The books are meant to make you question your own assumptions of what is good or right. I think what many people like about Banks is that he did not write simple morality plays. Iain Banks also wrote mainstream novels so you could say that he wasn't coming from the normal genre writer's perspective.
Wasn't banks pretty clear that the Culture was his attempt to come up with a society that is as "good" as possible - if nothing else to provide a suitable employer for his supreme military genius (who I shall avoid naming).
Edit:
CNN: Would you like to live in the Culture?
Iain M. Banks: Good grief yes, heck, yeah, oh it’s my secular heaven….Yes, I would, absolutely. Again it comes down to wish fulfillment. I haven’t done a study and taken lots of replies across a cross-section of humanity to find out what would be their personal utopia. It’s mine, I thought of it, and I’m going home with it — absolutely, it’s great.
By and large they're the good guys, or the least-worst guys anyway. Consider Phlebas is the weakest of the series IMO which is a shame as it's dealing with some interesting issues.
I interpret it as that they're mostly the good guys, but Consider Phlebas is written from the point of view of someone who opposes the Culture.
The main thing the Culture did that wasn't what I'd call a "good guy move" was destroying the orbital rather than allowing it to be used as a foothold by the Idirans. Basically, the Culture decided that winning was more important than holding the moral high ground.
The 'dark forest model' is predicated on game theory. This same model controls nuclear conflict doctrine on earth and is responsible for megatons pointed at you right now. An old 50's methodology, absorb the Russians since we cant beat icbm's and dont trust they would disarm under a treaty.
In a multiploar world arms races continue (this then is a mini analogue for grabby aliens but based on nation states). Worryingly usa now seeks asymetric dominance in this area increasing the likelyhood of conflict (or is it worrying?).
I would say at this point that perhaps advanced intelligences, or even aumented humans of 50 years hence! Or decentralised direct democracies of 5 - 10 years from now! Or me! May consider 'game theory' and its paranoid centralised power adherants as psychotic and a smaller filter in of itself ( to our kind of socially structured lifeform).
The dark forest has as its conlusion relativistic first strike weapons ( the same as the missile 'shield' )
I would think grabby aliens + uplift and absorption would answer the question of how they deal with new life.
Dark forest is a fad imho, and if im wrong, well i dont think we'll be like that, and we will still succeed if we get out of this period
I think you're underestimating the orders of magnitude in development that is possible. Even if an "enlightened" species was light-speed expanding at us right now, and they decided to leave us our entire solar system out of the goodness of their hearts, that would still prevent us from ever matching their expansion, because once we grew to the point that we'd like to light-speed expand into our neighborhood, there'd be no neighborhood to expand into.
Absolutely trivial for an interstellar space-faring civilization to wipe out an up-and-coming species. Grab a medium size asteroid[1] from their solar system, adjust its trajectory slightly, bam! An extinction event level weapon. This works because your basically rolling the rocks downhill, and there is a tremendous potential energy difference[2] between Earth and say, the Kuiper belt[3].
Or a bit of biological warfare - can't be too hard for a super-advanced civilization to tweak a virus to be a little more dangerous. Or maybe a bit of radioactive dust, or just poking a whole in the planets ozone layer; there are probably lots of subtle techniques that an advanced AI could pull off too. the point is, is you command the technology and energy reserves needed for interstellar travel, you don't really need to fight a prolonged war against a species on a lower technology level. Just check in every few thousand years and if it seems like they're starting to expand just wipe them out.
I'm currently reading Guns, Germs, and Steel, a book about the rise of civilization explained by their ecological starting points.
It's interesting how much luck people from Mediterranean had with all the crops and animals they could domesticate thousands of years before the humans in other places.
In light of what I read, we can only hope that we will belong to the first who will colonize the galaxy.
I have wondered about one of the premises of that book, the lack of animals that could be domesticated in the Americas, it may have been that the opportunity to domesticate them was lost after a certain amount of time passed and they went extinct due to hunting or climate changes.
Recently there has been found in Brazil huge amounts of rock art from prehistoric Ice age civilization, that showed that they drew pictures of ice age horses and a now extinct camelid species called a paleolama.
There is no reason to believe this model - the premise is pure conjecture. If I were engaging in pure conjecture - I might think equally, on the positive side, that all Aliens converge to the belief that all life is to be encouraged and supported, and turn into "meta-gardeners", seeding and encouraging life wherever they go.
It is no means a foregone conclusion that grabby v. gardener => grabby wins.
Perhaps grabby aliens, a known menace to life in the universe, are systematically exterminated when they are identified by other aliens in the universe.
There are really strong implicit assumptions at play here. This is a very interesting thought experiment, and it's nice to see novel thinking in this area. It's important to recognize however, that this is not "logical" or a "forgone conclusion" in any meaningful or systematic way.
I think people underestimate the gains that new technology will have for aiding our ability to see neighboring galaxies and exoplanets. For instance, our interpretation of spectral data is limited by both technological limitations (lasers can only probe certain wavelengths) and also theoretical ones. We also cannot accurately determine what happens in light matter interactions. Thus, the signal to noise ratio is so high that our current instruments have little chance of finding definitive evidence for life. This could change rather quickly though, the james webb telescope is one example, it is equipped with CCD that can "see" light in the infrared spectrum.
Assuming that neither FTL travel nor communication are possible, and that other intelligent species have life times similar in length to ours (ok, maybe twice as long as ours), how does a society spanning dozens of light years work? It would take more than a generation for information, never mind things, to get from one end of the bubble to the other. How would culture work? How would the economy work? Is it really the same society at both ends of the bubble?
Wouldn't population growth rate need be massive in order to overcome the large difference in volume that a small increase to the diameter of the sphere causes?
Given a quick scan, I don't see anywhere that takes into account population increases in the paper. The only way I think this works is if you count meeting the society's Von Neumann probes as meeting them.
If a grabby alien civilisation spreads out, then would not the frontier going parts become alien to each other, due to the distances and time involved, which will lead to both divergent development and difficulties with communication.
Given this, would each of the expanding parts in the animation have to fragment?
The source material for this does, we have the potential to become a grabby species. In particular though one of the strange things we can observe about the universe is how early we are, relative to how long we expect the universe to last. The grabby idea explains this puzzle pretty nicely by a selection effect: if the universe is going to be grabbed in the future (by us or others), then being early is the only time at all that we could find ourselves with our seemingly natural development history.
Almost. In their model, civilizations can start at different times, so it possible for the boundary between civilizations to be a hyperboloid, rather than flat as is the case for voronoi diagrams.
The 'Dark Forest' model suggests that we should be as quiet and inconspicuous as possible.
But I could also propose what I am calling the 'lumberjack model'. Suppose a lumberjack wishes to cut down all of trees in the forest--but being a sympathetic lumberjack, he avoids felling any trees with a birds nest in them. In that case, the birds should actively be as loud as possible and make their presence known to the lumberjack.
Both models are perfectly logical, but come to opposite conclusions--we simply have no idea whether aliens are more like the predators of the dark forest or the lumberjack.
As for Hanson's theory, it might be that the universe is one giant winner-takes-all system. But I suspect one could also come up with an equally valid theory that concludes something else--and we have no way to discern one over the other.
It's fun to speculate, I am just encouraging extreme caution I'm thinking we have any clue about any of this stuff.