[HN Gopher] Grabby Aliens
       ___________________________________________________________________
        
       Grabby Aliens
        
       Author : yosoyubik
       Score  : 55 points
       Date   : 2021-03-18 13:05 UTC (9 hours ago)
        
 (HTM) web link (grabbyaliens.com)
 (TXT) w3m dump (grabbyaliens.com)
        
       | bayesian_horse wrote:
       | 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.
        
         | mkl95 wrote:
         | > 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.
        
           | Symmetry wrote:
           | 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.
           | 
           | http://hopefullyintersting.blogspot.com/2018/05/falling-
           | fert...
        
           | jkaptur wrote:
           | 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.
        
             | mkl95 wrote:
             | https://en.wikipedia.org/wiki/Projections_of_population_gro
             | w...
             | 
             | The UN expect Asia, Europe and Latin America to start
             | declining in the 2090s, and for zero population growth to
             | be reached around that time. *
             | 
             | They estimate that population will eventually decrease by
             | about 1bn.
             | 
             | Edit: the study that estimates a decline of 1 billion was
             | published by The Lancet, not the UN.
             | 
             | * https://en.wikipedia.org/wiki/Zero_population_growth
        
             | rendang wrote:
             | Some countries' populations are already decreasing, like
             | Japan, and more are following close on the same path.
        
               | lupire wrote:
               | And USA is decreasing internally, but increasing overall
               | due to immigration.
        
         | Geee wrote:
         | 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.
        
           | sonofhans wrote:
           | 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.
           | 
           | edit: typo
        
             | dragonwriter wrote:
             | > 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.
        
               | sonofhans wrote:
               | > That's...not at all accurate.
               | 
               | 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.
        
               | dragonwriter wrote:
               | 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.)
        
               | ben_w wrote:
               | > Stephenson blithely writes as if this is true.
               | 
               | 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.
        
             | cyberpunk wrote:
             | I'm not sure it's so far fetched.
             | 
             | 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?
        
               | staticman2 wrote:
               | 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?
        
               | sonofhans wrote:
               | 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.
        
               | ben_w wrote:
               | > 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?
        
             | lupire wrote:
             | Consciousness isn't important for "digital" expansion. AI
             | is. If people build self-sustaining/replicating robots and
             | send them to stars, off they go.
        
             | arethuza wrote:
             | 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?
        
               | sonofhans wrote:
               | 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.
        
             | Chris2048 wrote:
             | 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".
        
           | flir wrote:
           | Even if you're spending all your time in Infinite Fun Space,
           | someone needs to stay home in base reality to make sure the
           | lights stay on.
        
             | praptak wrote:
             | 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.
        
               | arethuza wrote:
               | I will say that I found the end to the _Baroque Cycle_ in
               | _Fall; or, Dodge in Hell_ to be really satisfying.
               | 
               | I won't explain how it relates to your comment though -
               | go read all of them!
        
               | e40 wrote:
               | This one? https://en.wikipedia.org/wiki/The_Baroque_Cycle
               | I don't see a _Fall_ there.
        
           | darepublic wrote:
           | 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
        
           | arethuza wrote:
           | Have you read _Diaspora_ by Greg Egan?
           | 
           | https://en.wikipedia.org/wiki/Diaspora_(novel)
        
             | lazyweb wrote:
             | Read it a few years ago. The chapter describing an emerging
             | consciousness through a feedback loop is something I think
             | about every once in a while.
             | 
             | On a related note, currently working through 'Godel,
             | Escher, Bach'.
        
               | vcxy wrote:
               | Check out "I Am a Strange Loop" if you haven't. It's like
               | GEB, but he had a few more decades to refine the ideas.
               | Both great books though!
        
             | Geee wrote:
             | No, I haven't. Seems really interesting, thanks.
        
             | teekert wrote:
             | Came here to suggest this novel... as it answers OP with:
             | Why not both?
        
           | hindsightbias wrote:
           | Running at 4GHz, you're going to get tired of existence a lot
           | faster than you would in the physical world.
        
             | flir wrote:
             | 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.
        
             | lupire wrote:
             | You can create new virtual worlds to enjoy.
        
               | ben_w wrote:
               | 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.
        
           | speeder wrote:
           | 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).
        
         | tlb wrote:
         | 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.
        
           | qayxc wrote:
           | > 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.
        
           | staticman2 wrote:
           | Expansion is only selected for in the evolutionary
           | environment.
           | 
           | In layman's anthropomorphic terms, your genes can want to
           | expand on your home planet and say "hell no" when you find
           | yourself in orbit.
           | 
           | Your genes can want you to expand and express this as playing
           | Star Trek explorer video games all day.
           | 
           | In short, it's complicated.
        
             | tlb wrote:
             | 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.
        
         | ASalazarMX wrote:
         | 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.
        
           | frenchy wrote:
           | 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.
        
             | ASalazarMX wrote:
             | > 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.
        
               | frenchy wrote:
               | 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.
        
               | ASalazarMX wrote:
               | > we're probably less equiped to colonize space than the
               | chimpanzees in Africa are to build boats and sail to
               | Brazil
               | 
               | Surprisingly less prepared, if you count accidental
               | "boats" http://www.bbc.com/earth/story/20160126-the-
               | monkeys-that-sai...
        
         | vidarh wrote:
         | 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.
        
         | jdmichal wrote:
         | > 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.
        
           | deepstack wrote:
           | > 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.
           | 
           | Extra: some sci-fi look at Kardashev scale
           | https://en.wikipedia.org/wiki/Kardashev_scale
        
             | bayesian_horse wrote:
             | They wouldn't need habitable planets at all
             | 
             | 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.
        
               | lupire wrote:
               | Escaping a solar system just requires fuel and a freezer.
        
         | jjbinx007 wrote:
         | Any exploration would most likely be done remotely (at least
         | initially) as it's much simpler and easier than sending living
         | creatures.
        
           | bayesian_horse wrote:
           | Because of the distances, there is almost no point to even
           | sending anything like a simple probe there.
           | 
           | Any serious exploration would be a life-like colonization
           | attempt already, because of the challenges.
        
         | mynegation wrote:
         | It is really hard but the relative hardness of it may be very
         | different 100, 10000, 100K years from now.
         | 
         | As for the reasons: _if nothing else_ the expanding Sun outta
         | do it.
        
           | Taylor_OD wrote:
           | Exactly. Right now colonizing Mars is really hard. Will it
           | continue to be in 100 years?
        
             | bayesian_horse wrote:
             | 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.
        
         | BurningFrog wrote:
         | We've expanded to every remotely habitable region on Earth.
         | It's what we do!
         | 
         | Not because a big majority are ever gung ho about emigrating.
         | You only need a few misfits or outcasts who want to try
         | something different to start it.
        
           | trgn wrote:
           | 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.
        
             | BurningFrog wrote:
             | 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 :)
        
             | zentiggr wrote:
             | Boring and ugly are opinions, personally I would love to
             | roam around and just enjoy the variety.
             | 
             | Unlivable is the outstanding question, currently open.
        
               | frenchy wrote:
               | 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.
        
               | BurningFrog wrote:
               | If a billion Earthlings want to roam around Mars once in
               | their life, that's the basis for several permanent
               | tourist settlements there.
               | 
               | I also bet many would enjoy the low gravity on Mars and
               | the Moon. It might even be very health beneficial for
               | some.
               | 
               | Again, that's the basis for permanent medical facilities
               | there.
        
         | jerf wrote:
         | 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".
        
           | bayesian_horse wrote:
           | 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.
        
             | jerf wrote:
             | 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.
        
               | bayesian_horse wrote:
               | 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.
        
               | jerf wrote:
               | '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.
        
               | bayesian_horse wrote:
               | tl;dr; you don't make sense.
               | 
               | 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.
        
               | adwn wrote:
               | > _But for sure it 's a racist trope [...] but useful for
               | certain world views_
               | 
               | Please stop. HN is not the place for baseless accusations
               | of racism. Please assume good faith in discussions.
        
               | bayesian_horse wrote:
               | Well, you are repeating racist tropes, that why I said
               | that. It is not important to me that you know or believe
               | it yourself. That's up to you.
        
               | dragonwriter wrote:
               | > 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.
        
           | dahfizz wrote:
           | 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.
        
             | titzer wrote:
             | You can slice that even finer. There are plenty of people
             | who are not interested in moving away from their hometown.
        
               | ASalazarMX wrote:
               | That's because they live comfortably. Unexpected famine
               | and drought would motivate migration.
        
               | jdmichal wrote:
               | _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.
        
           | bildung wrote:
           | _> 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_
           | 
           | Where have I seen that argumentation before... oh yeah: https
           | ://en.wikipedia.org/wiki/Nazi_eugenics#/media/File:Bund...
           | 
           | That _was_ 3-5 generations ago, yet somehow didn 't come
           | true.
           | 
           | For this to really work like you state,
           | 
           | * the cultures have to be stagnant
           | 
           | * income has to be stagnant
           | 
           | * zero movement between cultures has to take place and so on.
           | 
           |  _> Because while a lot of cultures and subcultures are
           | choosing not to have lots of children, it is not uniform by
           | any means._
           | 
           | It is when you control for income, though: The more wealthy
           | nations become, the less children get born. Even inside the
           | US, when you group by income brackets:
           | https://www.statista.com/statistics/241530/birth-rate-by-
           | fam...
        
             | bayesian_horse wrote:
             | 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.
             | 
             | Certainly sounds similar...
        
               | mcguire wrote:
               | Independently reinvented eugenics is still eugenics.
        
             | Chris2048 wrote:
             | > yet somehow didn't come true
             | 
             | Isn't it? How would you prove/disprove this?
             | 
             | > oh yeah: <Nazi_eugenics>
             | 
             | 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.
        
           | staticman2 wrote:
           | 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.
        
       | eigenhombre wrote:
       | Which one of the colored blobs is the Culture?
        
         | vnxli wrote:
         | 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.
        
           | ngvrnd wrote:
           | neither/both
        
           | Super_Jambo wrote:
           | Banks likes twists. The Culture is his attempt at writing a
           | viable techno utopia. Every other book has a more pro-culture
           | viewpoint.
           | 
           | But if you're after 'good guys' and 'bad guys' Banks might
           | not really be for you.
        
             | vnxli wrote:
             | I think that's my answer. I like good guys/bad guys.
             | There's enough grey areas and anti heroes in real life. I
             | want simpler fiction
        
             | arethuza wrote:
             | 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.
        
           | wannadingo wrote:
           | 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.
        
           | messe wrote:
           | The Culture believe they are the good guys, and that they are
           | mostly in the right.
        
             | arethuza wrote:
             | And they have the data to justify that position, even then
             | they still run control experiments, which is where we fit
             | in...
        
           | simonh wrote:
           | 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.
        
           | elihu wrote:
           | 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.
        
       | chris_wot wrote:
       | Has anyone ever considered _we_ may be the grabby aliens?
        
         | Jach wrote:
         | 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.
        
       | patwillson22 wrote:
       | 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.
        
       | implying wrote:
       | The paper (and code) describe a 3D voronoi diagram, and imagine
       | what it would be like if each segment was an alien civilization.
        
         | fogof wrote:
         | 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.
        
       | reason-mr wrote:
       | 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.
        
         | lupire wrote:
         | The point is that if grabby and gardener aliens exist, grabby
         | aliens will dominate.
         | 
         | It's similar to the idea in evolution that we species that like
         | to reproduce more than species that don't.
        
           | arbitrage wrote:
           | 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.
        
           | jjtheblunt wrote:
           | But in gardening, overinvasive species are weeds and they are
           | removed by gardeners?
        
             | Aeronwen wrote:
             | The gardener merely holds the weeds at bay for a while.
             | Without constant upkeep, the weeds take over again.
        
       | FpUser wrote:
       | Loved the audio track
        
       | k__ wrote:
       | 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.
        
         | Herodotus38 wrote:
         | 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.
         | 
         | https://www.theguardian.com/science/2020/nov/29/sistine-chap...
        
           | k__ wrote:
           | The book mentioned something about humans hunting potentially
           | domesticatable animals too extinction around the time of the
           | ice age.
           | 
           | The climate wasn't good enough for agriculture yet, so people
           | had to rely more on hunting and gathering.
        
       | cyberlab wrote:
       | > and they prevent other beings like themselves from emerging
       | within their volume
       | 
       | What so they go to war with other species who are unlike them?
       | Doesn't sound very clever, and it's a losing strategy. 'War is a
       | losing strategy' [0].
       | 
       | [0] https://en.wikipedia.org/wiki/No-win_situation
        
         | olooney wrote:
         | 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.
         | 
         | [1]: https://en.wikipedia.org/wiki/Asteroid_capture
         | 
         | [2]: https://xkcd.com/681/
         | 
         | [3]: https://solarsystem.nasa.gov/solar-system/kuiper-
         | belt/overvi...
        
           | andredz wrote:
           | Your comment brought the prologue of this novel
           | https://www.royalroad.com/fiction/32411/bens-damn-
           | adventure-... to my mind.
        
         | borepop wrote:
         | >'War is a losing strategy'
         | 
         | Except in virtually all of human history, which is written by
         | the powers that win wars.
        
           | [deleted]
        
           | V-2 wrote:
           | Humans wage wars against other humans, because we compete for
           | the same resources. But fruit flies and giraffes pretty much
           | ignore eachother.
        
         | jerf wrote:
         | 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.
        
       | Dumblydorr wrote:
       | 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.
        
         | dj_mc_merlin wrote:
         | 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.
        
         | wing-_-nuts wrote:
         | 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.
        
         | vanviegen wrote:
         | 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!
        
           | Cthulhu_ wrote:
           | 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.
        
           | V-2 wrote:
           | _" 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.
        
         | scientaster2 wrote:
         | 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!
        
           | umvi wrote:
           | This is true but the amount of energy needed to reach speeds
           | where time dilation makes your journey seem short are just
           | unfathomable.
        
         | BurningFrog wrote:
         | I don't think we're that many decades from being able to send
         | frozen eggs, sperm, microbiome and food production capacity in
         | a spaceship.
         | 
         | When you're near the target, fertilize in an artificial womb,
         | raise the kids with Khan Academy v999, and let them land the
         | ship when they're ready.
        
         | jerf wrote:
         | 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.
        
       | mchusma wrote:
       | 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.
       | 
       | Some relevant ones: The Fermi Paradox Compendium
       | https://www.youtube.com/watch?v=rDPj5zI66LA
       | 
       | Fermi Paradox: The Dyson Dilemma v2.0
       | https://www.youtube.com/watch?v=QfuK8la0y6s
       | 
       | 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.
        
       | olooney wrote:
       | 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?
       | 
       | [1]: https://wmap.gsfc.nasa.gov/universe/uni_life.html
       | 
       | [2]: https://www.physlink.com/education/askexperts/ae465.cfm
       | 
       | [3]: https://en.wikipedia.org/wiki/Breakthrough_Starshot
       | 
       | [4]: https://www.extremetech.com/extreme/294051-scientists-
       | simula...
        
         | khafra wrote:
         | 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.
         | 
         | [1]
         | https://www.stat.berkeley.edu/~aldous/157/Papers/cirkovic.pd...
        
         | m4rtink wrote:
         | If the slightly insane Nuclear Salt Water rocket can be
         | pertectec then couple percent light speed might be doable even
         | without complex exotic tech:
         | 
         | https://en.m.wikipedia.org/wiki/Nuclear_salt-water_rocket
        
           | ngvrnd wrote:
           | "slightly"???
        
         | sliken wrote:
         | 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.
        
       | nanna wrote:
       | Grabby aliens = projecting human colonialism across the cosmos,
       | featuring an especially dubious technological determinism. Am I
       | missing something?
        
         | Symmetry wrote:
         | Not just human colonialism but also the colonialism that ants,
         | rabbits, and kudzu exhibit.
        
         | medicineman wrote:
         | Not missing anything, you brought enough snark for the whole
         | class.
        
       | jccalhoun wrote:
       | 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.
        
         | sandworm101 wrote:
         | >> 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.
        
           | wittyreference wrote:
           | Are machines immune to entropy? If not, I suspect that a few
           | thousand years of transit time still pose an obstacle, even
           | for a machine civilization.
        
         | Chris2048 wrote:
         | 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
        
         | causasui wrote:
         | 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.
        
         | AnIdiotOnTheNet wrote:
         | 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".
        
         | ben_w wrote:
         | 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
        
       | CRUDite wrote:
       | 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
        
       | Gunax wrote:
       | 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.
        
         | lhorie wrote:
         | 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.
        
           | Chris2048 wrote:
           | 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.
        
             | lhorie wrote:
             | 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.
        
         | anthony_romeo wrote:
         | 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.
        
         | lnanek2 wrote:
         | Most theories like this are starting from the place of trying
         | to solve the Fermi Paradox:
         | https://en.wikipedia.org/wiki/Fermi_paradox
         | 
         | 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.
        
           | TTPrograms wrote:
           | The Fermi Paradox is not real if you consider the massive
           | uncertainty we have on the parameters of the Drake equation:
           | 
           | https://arxiv.org/abs/1806.02404
        
           | sfg wrote:
           | 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.
        
             | sandworm101 wrote:
             | >> 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.
        
               | sfg wrote:
               | So, alone or they're hiding?
        
               | aaroninsf wrote:
               | 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.
        
               | sandworm101 wrote:
               | >> 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.
        
         | Lichtso wrote:
         | > 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.
        
           | lowbloodsugar wrote:
           | Right?
           | 
           | Oh, look, a new continent! Let's kill nearly everyone on it.
           | 
           | Oh, look, a new planet! ...
        
             | mdoms wrote:
             | 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.
        
               | speeder wrote:
               | 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.
        
               | blaser-waffle wrote:
               | 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.
        
               | savanaly wrote:
               | 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?
        
         | jpdaigle wrote:
         | 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.
        
           | lucozade wrote:
           | > 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.
        
           | Chris2048 wrote:
           | > oxygen-rich atmospheres probably indicate life
           | 
           | 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.
        
       | ericb wrote:
       | 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.
        
       | ncmncm wrote:
       | Expanding Menaces explored here [0]. Tl;dr: Expanding menaces get
       | nipped pretty early by inconceivably older non-menaces with
       | limited patience.
       | 
       | [0] <https://news.ycombinator.com/item?id=26440071>
        
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