[HN Gopher] Beyond "Fermi's Paradox" XVI: What Is the "Dark Fore...
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       Beyond "Fermi's Paradox" XVI: What Is the "Dark Forest" Hypothesis?
        
       Author : Hooke
       Score  : 154 points
       Date   : 2021-07-15 04:31 UTC (1 days ago)
        
 (HTM) web link (www.universetoday.com)
 (TXT) w3m dump (www.universetoday.com)
        
       | InsomniacL wrote:
       | I have a theory that intelligence isn't particularly rare however
       | the rate of development may be. It has long been alluded to in
       | Sci-Fi that humanity's rate of development is fast (Humans vs
       | Vulcans, Halo universe, etc). I imagine that one of the great
       | barriers is that a civilisation with a lower rate of development
       | may stuck in an industrial type era unable to progress before
       | doing irreparable damage to their environment/eco-structure. Does
       | anyone know if this theory has a name?
        
         | yarg wrote:
         | I think that the biggest issue's gonna be a time gap.
         | 
         | Life shows up and spends a long time doing not much, then
         | exponential growth kicks in, life gets smart and suicides out
         | in 100000 years or so.
         | 
         | The rate of intelligent and communicating planets is going to
         | be low enough; the chance of two such planets within a distance
         | that allowed for bidirectional communication existing
         | simultaneously is dwindling - and even then they'll be at
         | different points in their growth curves.
         | 
         | If ever we meet aliens they'll be cavemen or gods.
        
           | chadwittman wrote:
           | Love that quote: "If ever we meet aliens they'll be cavemen
           | or gods."
        
         | rybosworld wrote:
         | That seems like an idealization of humanity imo, and is common
         | in sci-fi. The most likely scenario is that we are average in
         | every way.
        
         | handrous wrote:
         | > It has long been alluded to in Sci-Fi that humanity's rate of
         | development is fast (Humans vs Vulcans, Halo universe, etc).
         | 
         | I think that's just borrowed from modern fantasy tropes. How
         | can humans co-exist on anything even kinda like equal footing
         | with centuries-old magical elves, ancient dwarves who know the
         | secrets of the deep, bloodthirsty and strong orcs and goblins,
         | et c? Oh, humans are more flexible (culturally more diverse;
         | more varied from person to person; develop & experiment faster;
         | are more curious; freer from genetic determinism in their
         | choices and behavior), breed faster, or cooperate better.
         | 
         | Usually one or more of those is the answer given, with the
         | specific question being "how can we have interesting and
         | powerful fantasy species/races and still have humans matter in
         | our stories, without every story just being an
         | upstairs/downstairs thing or otherwise having the humans in
         | some plainly-inferior position?" There are other ways around
         | the problem, but that's the easy way out.
        
         | qayxc wrote:
         | It's one of the Great Filters [0] - I don't know if it has a
         | catchy name.
         | 
         | [0] https://en.wikipedia.org/wiki/Great_Filter
        
         | yreg wrote:
         | To be fair, even with our (fast paced?) rate of development we
         | have a hard time to tech fast enough to outrun the industrial
         | damage.
         | 
         | On the other hand, only total extinction might be truly
         | "irreparable".
        
           | hnbad wrote:
           | It's also not correct to claim we are no longer "stuck in an
           | industrial type era" just because most of the Western world
           | is post-industrial. We largely offloaded the industrial era
           | into the third world.
           | 
           | You don't see kids in coal mines in England but you do see
           | people dipping circuit boards in vats of acid without
           | protective equipment in India. We may be investing in
           | renewables in the US and Europe but we still flood parts of
           | Africa and the Sea with crude oil and all that lithium
           | doesn't mine itself.
           | 
           | The "Industrial Age" may be over but the damage is still
           | being done and all the shiny new tech is largely window
           | dressing. It's also not yet clear that the shiny post-
           | Industrialism can easily exist without the rest of the world
           | perpetually playing "catch-up" (i.e. whether it really is
           | catching up) as our quality of living heavily hinges on
           | underpaying other countries for resources and labor.
        
       | [deleted]
        
       | zabzonk wrote:
       | Note that this is just one in a series of articles - check out
       | the links at the end.
        
       | MarkLowenstein wrote:
       | My theory, and I don't know why this is never mentioned: all
       | societies eventually retreat into inhabiting a purely simulated
       | universe (Matrix/Holodeck), where EM emissions and space
       | exploration become a thing of the past, and the society just
       | "goes dark".
       | 
       | The dynamic that guarantees it is that great stuff is almost
       | always cheaper/easier to experience via simulation than in
       | reality. We already know that TV plots and video game situations
       | are endlessly more entertaining than our real-world lives.
       | Arranging computing power that can fool our eyes and ears is way
       | easier than mustering the materials to get ourselves into space.
        
         | yoz-y wrote:
         | Isaac Arthur mentions this several times. But the counter
         | argument is that with advanced civilisations having gigantic
         | populations, it is hard to imagine that a "small" group
         | counting in quadrillions wouldn't prefer to live in the real
         | world.
        
       | baron_harkonnen wrote:
       | Given that most complex life is probably carbon based, and given
       | the one planet with complex life we can observe, my guess is that
       | most complex life runs into one of two paths:
       | 
       | 1. You don't have enough easily accessible hydrocarbons in ground
       | to build a civilization advanced enough to even get you into
       | space.
       | 
       | 2. You do have enough hydrocarbons which leads to inevitable
       | overshoot, and accompanying collapse before you ever get close to
       | figuring out interstellar travel. Exponential growth patterns
       | lead you to either exhaust the carrying capacity of your planet,
       | or you end up warming your planet too much and die off (or a
       | little bit of both).
       | 
       | We're a pretty good case study between 1 and 2. Right now we're
       | in a race to see if we can exhaust our hydrocarbons or overheat
       | our planet first, there seems to be no realistic alternative
       | (plenty of nice fantasy ones though).
       | 
       | If we had reached peak oil in the early 80s (or sooner) we would
       | have likely avoided catastrophic climate change, but would have
       | started a major population shift downwards towards 1 billion,
       | where we would have likely stabilized but with no major technical
       | progress (technological progress is largely a function of
       | energy).
       | 
       | We didn't though, so now it seems like we are going to continue
       | to increase the rate we combust hydrocarbons until we create an
       | unlivable planet (at least for us). A few billionaires are making
       | some cool toys, but we don't seem to be able to survive until
       | we're anywhere near interstellar travel.
        
       | overgard wrote:
       | I'm not an expert by any means, but I guess I've always felt
       | skeptical that if alien civilizations existed we would have the
       | means to detect them. I mean, we can _barely_ detect planets, if
       | we look carefully. Unless one of these civilizations really
       | wanted to make itself seen by desperately spending a ton of
       | energy, it seems like they would mostly be invisible just because
       | we don 't have sensitive enough means to detect them.
       | 
       | I personally find it impossibly unlikely that we are the only
       | intelligent life. It's just, there's nothing in the universe that
       | doesn't repeat. And there is a lot of space for us to repeat. Our
       | solar system likely isn't all that special, so I just don't get
       | that we could be the only thing that appeared in all the
       | conceivable universe.
       | 
       | It also might be the case that we're not alone, but that life is
       | just so hard to get going that maybe the nearest civilization is
       | galaxies apart from us. In that sense I suppose we really are
       | "alone" for any practical purpose.
        
       | Symmetry wrote:
       | One paper on the Fermi Paradox I want to plug is this one by
       | Sandberg, Drexler, and Ord.
       | 
       | https://arxiv.org/abs/1806.02404
       | 
       | Most people when doing the Fermi estimate for the number of
       | civilizations in the Galaxy use numbers that tend to result in a
       | lot of them. But different people use very different numbers in
       | different steps. If you look at the ranges of values that
       | different people assign to the different terms then suddenly it
       | doesn't seem very unlikely that intelligent civilizations could
       | be rare.
        
       | detritus wrote:
       | Huh. I could've sworn the name and concept of the Dark Forest
       | hypothesis predated Liu Cixin's book. Obviously I have it
       | completely arse-about-face - I thought he developed the series
       | based upon the concept, not the other way around.
        
         | burntsushi wrote:
         | This blurb has some citation links that suggest it predated Liu
         | Cixin's book:
         | https://en.wikipedia.org/wiki/Fermi_paradox#Communication_is...
         | 
         | My understanding was that Cixin's book gave it the name "Dark
         | Forest," along with the eerie analogy.
        
           | detritus wrote:
           | Aye, the basic concept was covered in this a couple of
           | decades ago - https://en.wikipedia.org/wiki/The_Killing_Star
           | (which has just about as dark a conclusion as Cixin's trilogy
           | does), but it was the actual Dark Forest name specifcially I
           | thought existed prior.
           | 
           | Clearly I'd been unwittingly absorbing output from people
           | who'd already read his books ahead of me!
           | 
           | - ed oh! I see The Killing Star's mentioned in the original
           | linked article. It's worth a read, if you haven't already.
        
           | andyjohnson0 wrote:
           | Greg Bear's novels _Forge of God_ (1987) and _Anvil of Stars_
           | (1993) explore the same idea. They feel a little dated now
           | but the first one in particular is still well worth a read
           | imo.
        
             | detritus wrote:
             | Huh, I can't remember that [apparently fundamental] aspect
             | of those two books. I'm going to see if I still have a copy
             | of Forge of God on the bookshelf when I get home later,
             | thanks.
             | 
             | Last time I re-read one of his books (Eon, probably), I was
             | quite bemused by the comically-simplistic 80s-esque Cold
             | War perspective though!
        
               | andyjohnson0 wrote:
               | [spoilers]
               | 
               | In the first book the earth is attacked by Von Neumann
               | probes launched preemptively by a civilization that wants
               | to destroy potential agressors before they develop the
               | technology to become a risk. The "benefactor"
               | civilization group organises rescue and counter-assaults
               | as a means of pan-civilisation trust building. The second
               | book looks at the ethics of destroying a civ based on
               | decisions it may have taken in its distant past.
               | 
               |  _Anvil_ has something of a young adult style, but the
               | game theory and strategy elements are quite satisfying I
               | think.
        
       | zhynn wrote:
       | A group collaborating will have better chance of survival than an
       | individual. The upside of working with your neighbors outweighs
       | the benefit of destroying them.
        
         | chadwittman wrote:
         | Tell that to the species we've eradicated while pursuing our
         | goals.
        
         | qayxc wrote:
         | That might be true for individuals of the same (social)
         | species, but I don't think that's a given in the context of
         | technological civilisations competing for resources.
        
         | dfilppi wrote:
         | Perhaps. But we're not talking about individuals.
        
       | taneq wrote:
       | Just started book 3, I'm clearly being Baader-Meinhoff'd. I think
       | the basic logic of preemptive first strikes being the universally
       | safest response is sound, assuming the current trend continues
       | that a species' offensive capabilities will grow faster than its
       | defensive capabilities as it improves its mastery of physics.
       | Even if in the short term, some civilizations are inherently
       | friendly and some are inherently hostile, in the long term the
       | chances of any randomly selected civilization being hostile
       | approaches unity due to survivor bias.
       | 
       | It's pretty similar to one of my favourite quotes, from Peter
       | Watts:
       | 
       | > Equidistant to the other two tribes sat the Historians. They
       | didn't have too many thoughts on the probable prevalence of
       | intelligent, spacefaring extraterrestrials-- but if there are
       | any, they said, they're not just going to be smart. They're going
       | to be _mean._
       | 
       | (I'm admittedly finding a lot of the other plot points of the
       | series, especially around how people respond to adversity, less
       | convincing though.)
        
       | raldi wrote:
       | Note that the Arecibo message diagram in this article is wrong;
       | the image is flipped left-right from how it's typically
       | displayed, so when the opening is described as "the numbers 1-10
       | from left to right", it's actually from right to left.
        
       | rnhmjoj wrote:
       | > In other words, the finite nature of resources will ultimately
       | pit one civilization against another as they all struggle to
       | sustain their growth.
       | 
       | I'm not sure this constraint is so strict to force a strong
       | competition for survival, given how vast the universe is. It
       | seems to me this projecting our earth-bound mentality of limited
       | resources to a whole different scale, where it may not really
       | apply.
        
         | dragonelite wrote:
         | Once we are earth loose we will be solar bound and human
         | factions will fight for solar resources/domination.
        
           | pharke wrote:
           | During star formation up to half of the matter can be
           | rejected. During planetary formation a lot of fairly large
           | bodies will be ejected, think moon size, along with a lot of
           | smaller stuff too. Interstellar space probably has a lot more
           | to offer than we generally think.
        
         | AmericanChopper wrote:
         | According to this theory, the resource consumers in the
         | universe are just as vast as the universe itself. At the end of
         | the series the final resource constraint they deal with is
         | running out of physical matter in the universe. Once the
         | civilizations depicted in the book are done mastering survival
         | in this universe, they all turn their attention to surviving
         | the death of the universe. Stability simply moves the survival
         | goalposts, and "we could probably last a few billion years" (or
         | rephrased, "we will probably perish in a few billion years")
         | becomes the new existential crisis to solve.
        
         | [deleted]
        
         | mikro2nd wrote:
         | Precisely. IMHO any civilisation capable of interstellar travel
         | (at any speed) has solved all necessary questions/problems of
         | resource/energy acquisition and control and has no need to
         | plunder the resources of others.
        
         | riffraff wrote:
         | that is what I thought when I read the three-body problem.
         | 
         | If you can manipulate space-time at the levels exposed in the
         | book you can trivially build orbitals that will host trillions
         | of beings and live in a post-scarcity society for millennia,
         | after which your society is likely to disappear waaay before
         | you run out of space and resources.
        
           | yoz-y wrote:
           | Why or how would a post scarcity multi planetary or even
           | multi stellar civilisation disappear? I agree that there is
           | no need for plunder, but I don't think highly advanced
           | civilisations are in risk of extinction.
        
             | riffraff wrote:
             | Well, I don't know.
             | 
             | It is just a common topic in fiction that great
             | civilizations just fade out, and it seems reasonable to me.
             | I do not believe the average individual would want to live
             | forever, and at some point I feel the same would apply to
             | civilizations. But for the sake of fun, I can recall some
             | ideas from literature :)
             | 
             | Maybe they evolve into higher states of being and leave our
             | plane of existence.
             | 
             | Maybe they stop reproducing and slowly die out.
             | 
             | Maybe they reach a level of self-introspection where they
             | believe continuing existing is pointless.
             | 
             | Maybe they migrate to a more reliable virtual world in a
             | sub-space computer.
             | 
             | Maybe each individual gets its own universe.
             | 
             | Maybe the society splinters over some trivial concepts and
             | the old knowledge is lost when the machines start to fail.
             | 
             | There's a lot of interesting things that can happen, let's
             | hope we'll find out late enough :)
        
       | pdimitar wrote:
       | > _In other words, the finite nature of resources will ultimately
       | pit one civilization against another as they all struggle to
       | sustain their growth._
       | 
       | I absolutely can't see how that follows exactly. The Universe,
       | hell, just our own galaxy, is pretty damn _big_. The time and
       | fuel it could cost you to get to the adjacent civilization and
       | steal its resources might be way too much compared to, you know,
       | invest in some cosmic mining operations where you can get a
       | Bonanza of resources just by poking into your local asteroid
       | cluster.
       | 
       | To address the rest of this argument, a civilization might be as
       | malicious as they come and they could still be very powerless and
       | can't just go terrorize somebody.
        
       | formerly_proven wrote:
       | This paper discusses the "dark forest" idea and concludes that it
       | is very unlikely to be true: https://arxiv.org/abs/1302.0606 MAD
       | with Aliens? Interstellar deterrence and its implications
        
         | AmericanChopper wrote:
         | The "MAD with Aliens" portion of the book isn't particularly
         | relevant to the dark forest theory it postulates. The MAD in
         | the book only applies to a conflict between earth and another
         | nearby non-technologically-sophisticated alien spices, who are
         | competing for earths resources in order to survive. The
         | conflict is resolved by both us and them advancing beyond the
         | need for earth, and becoming full dark forest participants.
        
       | rvba wrote:
       | I dont understand why politicians allow those active messages
       | sent - most people probably dont want them.
        
       | Mordisquitos wrote:
       | Am I missing something, or is this article very narrowly missing
       | the most damning criticism of the Dark Forest hypothesis
       | according to the article's own logic? The first paragraph of the
       | " _Criticism_ " section says:
       | 
       | > _Overall, the Dark Forest Hypothesis has an internal logic and
       | consistency that makes it an appealing (if somewhat somber)
       | potential resolution to Fermi's age-old question. Unfortunately,
       | it also suffers from an inherent flaw that is capable of
       | unraveling the whole thing. Like many other Fermi-related
       | hypotheses, it only takes one exception to this rule to prove it
       | wrong._
       | 
       | Given this, I thought it was going to follow on to point out that
       | _we_ are the exception to the rule, but instead it goes on to
       | talk about malevolent exceptions. But, as the article mentioned
       | earlier, we have made many active attempts to communicate our
       | existence to other hypothetical civilisations, and we make no
       | effort in obscuring our radio signals.
       | 
       | Is it possible that other civilisations follow the "Dark Forest"
       | principle? Of course it is! But why would we happen to be the
       | only civilisation that doesn't really worry about getting seen?
       | The possibility that we are not alone _and_ we are the only ones
       | trying to communicate sounds even more fanciful and
       | anthropocentric than any of the alternatives.
        
         | LatteLazy wrote:
         | 1 exception doesn't disprove this rule. There could be any
         | number of reasons for one or some civilisations to broadcast
         | but not be destroyed:
         | 
         | * it takes time, we've only been broadcasting for 70 years or
         | so. 70 light years isn't that far.
         | 
         | * we are far from dangerous listeners (we are right out on an
         | arm in the milky way galaxy)
         | 
         | * all planets broadcast for a while at least (we did so without
         | any serious consideration) and not all broadcasts end in
         | annihilation. Up until just 40 years ago we seemed pretty
         | likely to wipe ourselves out with war, even if an alien were
         | planning our destruction, why not wait and see if we did it
         | ourselves?
         | 
         | * Popular methods of destruction might not apply to our solar
         | systems. If you rely on near by asteroids or free-floating
         | planets to destroy civilisations and there happen to be none
         | near sol, then we are safe to broadcast even if no one is safe
         | to reply.
         | 
         | * if more than 1 alien actively destroys planets we might be
         | lucky and have the aliens who detected us assume other aliens
         | will destroy us. As long as they are happy to wait, we can
         | broadcast in blissful ignorance believing we disproved the dark
         | forest when we're actually just in the middle of a Mexican
         | standoff...
         | 
         | * If a civilisation destroys other civilisations as soon as it
         | detects them, you can use the abrupt destruction of
         | civilisations to triangulate that civilisation. And destroy it.
         | And that's a high priority since that way you find hidden civs
         | AND ones which pose an immediate and serious threat to you. The
         | best defence against this is to allow plenty of time between
         | detecting and destroying a civilisation, especially a harmless
         | unarmed (in the cosmic scale) one like ours. The lack of many
         | close neighbours to us means a would be destroyer needs to wait
         | even longer before striking us to maintain their annonimity.
         | 
         | Ironically this last point is the best argument against the
         | dark forest: why destroy soft targets like earth when doing so
         | reveals your existence? Why not wait, let someone else hit us
         | and then hit them since they were a much bigger threat. So
         | you'd expect a certain amount of noisy "prey" to be left as
         | bait by one predator for another...
         | 
         | Also, I don't think we are broadcasting very much anymore. The
         | move to digital broadcasts (lower power) and to Internet based
         | comms/media (99% undetectable even from orbit) mean we're a lot
         | less visible than we were previously.
        
           | TaupeRanger wrote:
           | The book responds to most of the "not there yet" concerns.
           | The idea is that if there are 1,000 species aware of even
           | primitive life on a particular planet, chances are at least
           | one of them will be close enough for it to be worth the
           | effort to destroy it. This is because technological
           | development is exponential and you can't predict if/when a
           | planet will produce dangerous technology equal or greater
           | than your own. If you wait, you only increase the risk of
           | being destroyed.
        
         | nirui wrote:
         | Ah... the "Dark Forest Theory". People really put way too much
         | unnecessary time on it.
         | 
         | If the theory was true, then the first thing those "tree-body
         | man" would reasonably do is to just destroy the solar system
         | straight away with that super illegal (to the law of physics)
         | raindrop probe. A civilization with the intention of discover
         | and kill will definitely make their probes efficient kill
         | devices, right? Why pay the expense of identify and kill the
         | "Key actors" one by one when you can delete a entire system for
         | cheap? Just turn the probe into a blackhole to kill the sun, it
         | should be easy if the probe was really that dense.
         | 
         | A more direct attack is rooted in the theory itself: for the
         | theory to be true, a state/condition called Cai Yi Lian  (Chain
         | Of Suspicion) must be created. The content of Chain Of
         | Suspicion is simple:                   - A civilization cannot
         | determine if another civilization is evil         - A
         | civilization cannot determine if other civilizations will view
         | itself as evil         - A civilization cannot determine if
         | another civilization will launch an attack against it         -
         | A civilization cannot determine if itself is evil         - A
         | civilization cannot determine if another civilization view
         | themself as evil         - A civilization cannot determine if
         | another civilization will treat itself in such way that been
         | determined unevil         - ... ... (The article that I quoted
         | from has this at the last line: https://wiki.mbalib.com/wiki/%E
         | 9%BB%91%E6%9A%97%E6%A3%AE%E6%9E%97%E6%B3%95%E5%88%99#.E5.8F.B6.
         | E6.96.87.E6.B4.81.E6.8F.90.E5.87.BA.E7.9A.84.E2.80.9C.E5.9F.BA.
         | E6.9C.AC.E5.85.AC.E7.90.86.E2.80.9D.E5.92.8C.E4.B8.A4.E5.A4.A7.
         | E9.87.8D.E8.A6.81.E6.A6.82.E5.BF.B5)
         | 
         | Have you see the hole here? For a civilization that advanced,
         | what are the chances that they're not equipped with also
         | advanced social and science knowledge and skills? Heck, their
         | advanced probe could probably even do all the observation and
         | tests fully automatically and report the result back. The Chain
         | Of Suspicion will never form to begin with because they CAN
         | determine the facts if they really wants to. And then so the
         | Dark Forest will never form too (at least not for the advanced
         | side).
         | 
         | Now, let's talk about some serious thing. Because I've noticed
         | some people uses the Dark Forest Theory to explain the relation
         | between nations (yes, Earth nations). So it is really important
         | to realize that the entire theory is nothing more than a plot
         | device that Liu Cixin employed for his novel, among many other
         | plots. Most of them are there to make the story more
         | convenient, instead of more logical (as I have said, based on
         | the theory, the logical thing to do is to wipe everything out
         | at contact, how convenient that the probe "JuST cAnT" huh?).
         | 
         | So, if the theory inspired you do to something good, then nice,
         | go ahead, have a good life, help people, communticate with
         | others, try to understand others, have fun. However, if you
         | believe the "Dark Forest Theory" is THE true governing rule of
         | the universe, then you probably overthink it too much, stop it,
         | it's not healthy. And guess what, the planet we're living on
         | hosts multiple civilizations, you stick with us now no matter
         | what.
        
         | zabzonk wrote:
         | > The possibility that we are not alone and we are the only
         | ones trying to communicate sounds even more fanciful and
         | anthropocentric than any of the alternatives.
         | 
         | Well, yes. But it could also make the (possibly) few blithe
         | spirits who do want communicate be in general much further
         | away, and thus much harder to communicate with.
        
         | HotHotLava wrote:
         | Wouldn't the counterpoint be that those civilizations like us
         | that do not obscure their location are quickly eradicated by
         | others in the forest? So the forest also acts like a filter for
         | those that are not careful enough.
        
           | Mordisquitos wrote:
           | I don't see that as a counterpoint, but more of a _post hoc_
           | theory. How could the eradicators detect and destroy their
           | victims before we detected any signal at all from the
           | victims? And why haven 't the eradicators come for us yet?
           | 
           | Of course, this could always be explained by the distances
           | involved and the limitations of light speed, but that would
           | make the Dark Forest hypothesis redundant as an explanation
           | as to why we haven't yet detected any alien civilisation(s).
        
             | yreg wrote:
             | >How could the eradicators detect and destroy their victims
             | before we detected any signal at all from the victims?
             | 
             | Even if they destroy them within say a thousand years, then
             | at any given time there would be only few civilizations at
             | the right age to be broadcasting. And not very loud at
             | that.
             | 
             | We listen only to a miniscule portion of the Galaxy. IMO,
             | Fermi's question shouldn't be "Why can't we hear the few
             | civs that are close to our level".
             | 
             | It should be "How come we don't detect Kardashev >2 civs
             | collonizing most of the galaxy?" Why can't we detect a
             | single Dyson Sphere?
             | 
             | (I don't consider dark forest explanation to be probable
             | though.)
        
               | marcosdumay wrote:
               | The Fermi question is a lot closer to "how come Earth
               | wasn't colonized before we even appear?" than "how come
               | we can't see anybody?".
        
               | yreg wrote:
               | Yes, that's a cleaner way to put it.
        
               | mokus wrote:
               | How do we know we aren't the colonists?
        
               | marcosdumay wrote:
               | You mean how we know the Earth wasn't seeded with
               | something similar to archeo-bacteria on purpose? We don't
               | but that doesn't solve the problem.
               | 
               | Or how do we know that we, humans, aren't the colonists?
               | Well, all the life we know comes from the same ancestry,
               | including us.
        
               | yreg wrote:
               | That doesn't solve the paradox though, unless we are
               | quaranteened in a Zoo.
        
               | tjalfi wrote:
               | There have been a couple science fiction novels with this
               | premise:
               | 
               | Protector[0] by Larry Niven
               | 
               | David Weber's Dahak trilogy, available as the Empire from
               | the Ashes[1] omnibus
               | 
               | [0] https://en.wikipedia.org/wiki/Protector_(novel)
               | 
               | [1] https://en.wikipedia.org/wiki/Empire_from_the_Ashes
        
             | saiya-jin wrote:
             | I think what would explain this is our very limited
             | timespan when we started listening to universe. There might
             | have been 10 strong signals in last 2000 years, but last
             | one could have happened around the time US declared
             | independence.
             | 
             | And 2000 years is nothing timewise on scale of universe.
             | Plus we talk about signal that can maybe travel few hundred
             | / a thousand light years before they blend into galactic
             | and intergalactic noise.
        
             | taneq wrote:
             | > How could the eradicators detect and destroy their
             | victims before we detected any signal at all from the
             | victims? And why haven't the eradicators come for us yet?
             | 
             | Because most civilizations are probably still a 100+ light
             | years apart and we just haven't been around and listening
             | for that long? Even if we've theoretically had the chance
             | to detect another early civilization the other listeners
             | have been listening for aeons longer than us and are much
             | better at it.
        
           | Causality1 wrote:
           | I don't see there being that big a technological leap between
           | annihilating another civilization and starting a colony in
           | another star system. If you're the type of civilization that
           | would be interested in killing a competitor off you're
           | probably the type that's going to colonize and fill the
           | entire galaxy in a few million years. We evolved, so that
           | hasn't happened, in a galaxy thirteen billion years old. I
           | suspect we're alone.
        
             | syops wrote:
             | The energy requirement to send a life destroying device to
             | a far away planet might be much less than the energy
             | requirement to send colonizers. That may be the big leap so
             | to speak.
        
               | Causality1 wrote:
               | If you can send a weapon you can probably send some kind
               | of Von Neumann probe with genetic and cultural data to
               | create a seed colony
        
               | wonderwonder wrote:
               | Not really, the weapon does not need to slow down. If its
               | just a big enough chunk of rock that is aimed at a planet
               | and it speeds up the whole way reaching some impressive
               | fraction of the speed of light before impact, the only
               | hard part is the math to aim it. We are reasonably close
               | now to being able to strap some engines on an chunk of
               | rock and send it on its way randomly in one direction. We
               | are very far away from being able to start a seed colony
               | in another solar system.
        
               | syops wrote:
               | I don't see why that necessarily follows and I don't see
               | why one would want to send such a probe. It does nothing
               | for me if I can send a probe to start humanity on another
               | planet when I have no connection to said planet and won't
               | be able to see the result or have a connection to that
               | colony. In the dark forest view one would never seed such
               | a colony as they will quickly become competitors.
        
               | Causality1 wrote:
               | You don't think species chauvinism is a thing? If I had
               | to lose an interstellar war and be wiped out I'd prefer
               | it to be a human offshoot doing it. At least that way my
               | species survives.
        
               | syops wrote:
               | In the dark forest view it's best to just kill off the
               | opponent and not replace them with a potential new
               | opponent.
        
         | V-2 wrote:
         | Becoming truly detectable - on a cosmic scale - might require a
         | higher technological level than our current one.
         | 
         | Attaining that technological level could be inherently linked
         | with the ability to realize the dangers to begin with.
        
         | evrydayhustling wrote:
         | As other commenters have said, we can't take our own viewpoint
         | as an example of what kinds of civilizations _survive_ because
         | our technological age is so young.
         | 
         | But IMO Dark Forest is bunk anyway, because it assumes that
         | projecting power over interstellar distances is easier than
         | defending yourself. That's not true within terrestrial history
         | ... even though the arrival of colonists was massively
         | disruptive to populations in (for example) the Americas, they
         | couldn't have outright destroyed them. To survive, they had to
         | trade and mingle with their neighbors, ultimately changing both
         | cultures.
         | 
         | The sequels to The Three Body Problem kind of discuss this, and
         | extend the dark forest idea to consider that any population
         | that splits off from you is now a dark forest alien. I find
         | that crazy xenophobic and ultimately an impractical black and
         | white view of self vs other. On Earth, successful civilizations
         | have been capable of trade and cultural exchange in addition to
         | force.
        
           | bobcostas55 wrote:
           | >because it assumes that projecting power over interstellar
           | distances is easier than defending yourself
           | 
           | This seems really obviously true to me. Accelerating a rock
           | to relativistic speeds is pretty easy, defending against a
           | rock potentially coming from anywhere in space traveling at
           | relativistic speeds is extremely difficult.
        
             | gilbetron wrote:
             | > Accelerating a rock to relativistic speeds is pretty easy
             | 
             | Huh? How? I haven't seen any proposal that doesn't start
             | with the assumption that we can inject a rock with a
             | preposterous amount of energy let alone hit (in
             | astronomical scales) a ridiculously small target, not to
             | mention navigate all the gravity wells in between.
        
               | a1369209993 wrote:
               | Multistage rocket using ion engines. Remember this is
               | over interstellar distances (>4 lightyears), so you have
               | multiple years, if not decades or centuries to
               | accellerate.
               | 
               | This does get back to the "Why didn't we RKKV it millions
               | of years before intellegent life even existed, much less
               | had a opportunity to hide, based on biosignatures in the
               | atmosphere?", though.
        
             | evrydayhustling wrote:
             | IANAAstrophysicist but it seems like targeting that rock
             | gets proportionally hard with the speed and distance.
             | Throwing a dart and hitting an ant on the other side of the
             | world, etc.
             | 
             | And the other side of that equation is: does the species
             | who can do that have anything to fear from us? Or does the
             | same technology make them likely able to stay ahead on
             | defense, making it uninteresting to destroy us?
             | 
             | Three Body Problem introduces all this dimension folding
             | tech that makes being the first to strike totally dominate.
             | But the closest equivalent on Earth hasn't (yet) led to
             | nuclear holocaust, because preventing others from getting
             | the tech and establishing mutual detente with those who do
             | has been better for each actor.
        
               | Retric wrote:
               | We can already hit tiny (Ed: planet sized) targets at
               | interstellar distances. Planets are relatively speaking
               | quite large targets especially if you're tossing several
               | rocks.
               | 
               | This stuff doesn't need sci-fi style new physics, just
               | the kind of infrastructure we could actually build.
        
               | AnIdiotOnTheNet wrote:
               | ....we have never hit anything at _interstellar_
               | distances, which are several orders of magnitude farther
               | than _interplanetary_ distances.
        
               | Retric wrote:
               | I didn't say we have, just that we _can._
               | 
               | The closest Star is ~268,770 AU where voyager 1 is only
               | 152.6 AU. However, being able to target a probe within 50
               | feet at 150AU, means hitting a planet sized target at
               | 4.25 light years. Building a probe large enough and fast
               | enough to do significant damage at the other side is the
               | hard part, not targeting.
               | 
               | Calculating where a planet sized object would be by the
               | time our probe got there is a different story.
        
               | edgyquant wrote:
               | Voyager is not traveling a relativistic speeds. We could
               | definitely defend against someone sending voyager at us.
        
               | Retric wrote:
               | That's moving the goalposts. I said we could hit a planet
               | at those distances not that we can create a relativistic
               | impactor.
        
               | edgyquant wrote:
               | No it isn't since the whole topic here is that any
               | civilization capable of accelerating an object to
               | relativistic speeds and hitting a target from light years
               | away is capable of defending against one. We can send
               | voyager to target an object on the other side of the
               | solar system but we are also perfectly able to defend
               | against a potential voyager.
               | 
               | Just because you now claim to not be addressing the
               | actual goal at hand doesn't mean I moved the goalpost; if
               | anything you're now implying you did.
        
               | Retric wrote:
               | Voyager 1 isn't a weapon so defending against it is kind
               | of a meaningless argument. The Parker Soar probe is
               | aiming for 0.064% the speed of light and covered in
               | scientific instruments and shielding. So that's arguably
               | a solid baseline of what we could do in terms of speed.
               | Even at those speeds we are still talking 8,000 years to
               | the closest planet making it a poor weapon.
               | 
               | Still, I doubt we could detect a barrage of incoming
               | 0.0005c weapons designed for minimal levels of stealth in
               | time to do anything about it.
        
               | evrydayhustling wrote:
               | What tech are you thinking of? Remember it's not just the
               | distance but the speed. How would we course correct a
               | relativistic object once the target was close enough to
               | estimate the desired change?
        
               | marcosdumay wrote:
               | Well, you do that with the same kind of engines that
               | propels them at relativistic speed.
               | 
               | Anyway, it's not a target and forget situation, because
               | relativistic ships get a (relatively) lot of drag in
               | space.
        
               | edgyquant wrote:
               | Right, if you have the tech to allow you to course
               | correct an object traveling at relativistic speeds you
               | have the tech to defend against on by moving it out of
               | the way.
        
               | marcosdumay wrote:
               | Yep, that's probably correct. Even more because you can
               | just throw something into the projectile too, and destroy
               | it... And they can throw something into your projectile,
               | and etc.
               | 
               | I don't think anybody can make any claim on what side is
               | easier. But targeting the attack does not seem to be the
               | hard part.
        
               | Retric wrote:
               | The belief is that detecting the attack in time to do
               | anything makes defense more difficult. Your warning is
               | limited by light speed, so detecting something moving
               | .99c at 100 AU and you get just over 7 minutes to
               | respond.
               | 
               | Worse, it doesn't need to be some solid object. A loose
               | field of debris 1,000 miles wide could sterilize a planet
               | with enough mass and enough velocity.
        
               | gilbetron wrote:
               | > Well, you do that with the same kind of engines that
               | propels them at relativistic speed.
               | 
               | Which don't exist except as fantasy, and even most of the
               | fantasy ones wouldn't work for targeting adjustments.
        
             | a1369209993 wrote:
             | > defending against a rock potentially coming from anywhere
             | in space traveling at relativistic speeds is extremely
             | difficult.
             | 
             | Also, while 'proper' stealth is difficult, you can make the
             | rock pretty close to invisible for practical purposes by
             | coating it in vantablack and cooling it to liquid helium
             | temperatures.
        
             | roenxi wrote:
             | Fortunately, it is possible to imagine other scenarios. For
             | example; it would take relatively little energy to deflect
             | such a missile and there is likely to be a lot of time to
             | detect it's incoming presence assuming that some sort of
             | planet-like mass is required to host all the technology to
             | create a relativistic speed accelerating engine.
        
             | AnIdiotOnTheNet wrote:
             | 1) I think you're underestimating the difficulty of
             | accelerating any massive object to relativistic speeds, 2)
             | doing so with enough accuracy to hit a relatively small
             | moving target many light-years away is not exactly trivial,
             | 3) a civilization with the capability to accelerate a
             | massive object to relativistic speeds is probably also
             | capable of building self-sufficient artificial habitats
             | around its star, which is a lot of targets you'd have to
             | take out for complete obliteration.
             | 
             | So in summation, I think defending against an incoming
             | relativistic rock is at least as easy as using relativistic
             | rocks to obliterate a distant civilization.
        
               | riffraff wrote:
               | another thing: I believe at relativistic speeds hitting
               | any debris in your path would cause a pretty large BOOM,
               | and for a multi-lightyear route that seems somewhat
               | risky.
        
               | ping_pong wrote:
               | You're definitely not thinking creatively enough.
               | 
               | You don't need to hit the planet directly with anything,
               | all you need to do is destabilize the orbit of all the
               | planets or even just the Earth itself. You could send a
               | gravity wave for example, that would cause the Earth's
               | near circular orbit to shift to a very eliptical orbit.
               | The vast change in temperatures would kill all life on
               | the planet, and then you could come and mine all the
               | resources that you needed and leave.
        
               | AnIdiotOnTheNet wrote:
               | If you have the capability of engineering such a gravity
               | wave then Earth's resources aren't worth your time.
        
               | mentalpiracy wrote:
               | Resources not the point here, the point is removing the
               | possibility that our civ could ever be a risk to them
        
           | ping_pong wrote:
           | > On Earth, successful civilizations have been capable of
           | trade and cultural exchange in addition to force.
           | 
           | Forget about what monstrosities we have done to other human
           | civilizations throughout history. Instead, think about what
           | we have done to animals. We have hunted many animals out of
           | existence, or we have farmed them and made them basically the
           | equivalent of the Matrix, sources of energy and food.
           | 
           | We are trying to eradicate mosquitoes for crying out loud,
           | and entire species, without giving it a second thought. I
           | will use insecticide to kill today entire colonies of ants
           | without blinking.
           | 
           | All it takes is for one advanced alien civilisation to come
           | across us and deem us the equivalent of their mosquitoes to
           | eradicate us and take all the resources from the Earth.
           | That's the whole point of the Dark Forest theory. If there's
           | an infinite number of civilisations out there, and one of
           | them is so advanced that we are insects to them, why wouldn't
           | they just exterminate us, or use us as food?
        
             | tjalfi wrote:
             | John Varley's Eight Worlds[0] series has an alien species
             | called the Invaders. They invaded Earth to protect
             | cetaceans from the effects of human civilization.
             | 
             | The Invaders divide sentient life into three tiers -
             | species like themselves that evolve in gas giants,
             | cetaceans, and vermin; we're in the third category.
             | 
             | [0] https://en.wikipedia.org/wiki/Eight_Worlds
        
         | saberdancer wrote:
         | We are early in our "Space age". It's possible that
         | inexperienced civilizations emit their position only to start
         | hiding after realizing the dangers. Other possibility is that
         | we are in a short period until we are wiped out because we
         | broadcast our position.
         | 
         | All of this would drastically reduce number of visible
         | civilizations at any time making the detection of civilizations
         | much less likely.
        
         | ericmay wrote:
         | I don't think the Dark Forest principle asserts that all
         | civilizations adhere to it. We might simply be the naive (or
         | stupid) ones that get destroyed. That wouldn't discredit the
         | hypothesis.
         | 
         | We are also the only civilization we know of so we again may
         | just be the dumb ones with a sample size of 1.
        
         | wydfre wrote:
         | There is no way to underestimate the stupidity of people in
         | groups, and our eusocial stupidity _might_ be unique to our
         | species.
         | 
         | If someone knocked on your door, quite unexpectedly, in the
         | middle of the night, can I err on the idea that you would be
         | quite panic-struck?
         | 
         | But if humanity got a signal from another civilization
         | tomorrow, do you think it is safe to err on folks being quite
         | happy?
        
           | TheCoelacanth wrote:
           | > If someone knocked on your door, quite unexpectedly, in the
           | middle of the night, can I err on the idea that you would be
           | quite panic-struck?
           | 
           | Quite likely, but only because the socially acceptable
           | reasons to knock on someone's door in the middle of the night
           | are usually something pretty bad. I wouldn't fear that
           | they're attacking me. I would fear whatever they are waking
           | me up to tell me about.
        
           | riffraff wrote:
           | > If someone knocked on your door, quite unexpectedly, in the
           | middle of the night, can I err on the idea that you would be
           | quite panic-struck?
           | 
           | But if a stranger knocks on your door in the middle of the
           | day you might just open up and say "no thanks, I don't want
           | your pamphlet/vacuum/encyclopedia".
           | 
           | I mean, even if a stranger knocks, it seems weird to kill
           | them assuming they're dangerous, even if we have "don't let a
           | stranger in" etched in our collective consciousness.
        
       | abecedarius wrote:
       | > This particular proposed resolution to Fermi's Paradox question
       | is a very recent addition. It takes its name from the novel The
       | Dark Forest
       | 
       | The same idea was in Gregory Benford's novel _In the Ocean of
       | Night_ in the 1970s.
        
       | snowwrestler wrote:
       | To me the most likely back of the napkin answer to the Fermi
       | paradox is that aliens are elsewhere in time. The Milky Way
       | galaxy is about 100,000 light years across but about 13.5 billion
       | years old. So it's like 135,000x deeper in the time direction
       | than the distance direction.
       | 
       | We're in the light cones of all the stars we can see, and as far
       | as we know, we can't get out of them. If a civilization ended
       | even 100 years earlier than our equivalent "now" in their light
       | cone, we wouldn't have seen them. And if they became visible even
       | 1 year later than our equivalent "now," we would not have seen
       | them yet.
       | 
       | We're proceeding through time at 1 sec per sec and basically if
       | we're going to see an alien civilization at this point, I think
       | the only way would be if one happens to achieve the necessary
       | technology to be detected while we're looking at it. If there
       | were existing civilizations that were easy to see, we would have
       | seen them already.
       | 
       | I think it's far more likely we will confirm alien life first by
       | indirect means, for example spectroscopically detecting free
       | atmospheric oxygen on an exoplanet, or finding tiny fossils on
       | Mars.
        
         | kadoban wrote:
         | If true, that ends up meaning that alien civilizations are
         | short-lived, right? That doesn't bode well for us.
        
           | hashkb wrote:
           | We're on a steady path to extinction, no doubt.
        
             | throw1234651234 wrote:
             | Generalization. Would be interesting discussion with
             | details. Pop is growing. What's your concern - global
             | warming, fertility rates, pollution, nuclear arsenal,
             | running out of resources? Doesn't seem like we are doing
             | that badly and that pop can't drop if get below renewable
             | resource level or adjust to new ways of making energy/food,
             | etc.
             | 
             | Does seem likely that on an extremely long time scale, we
             | need to get multi-planetary, which is "realistic" if we
             | give a reasonable time frame of, say, 10,000 years.
             | 
             | As far as the sun dying, that's beyond even parent point's
             | timeline. This is very things start to get questionable if
             | we never get to even .1 of c (e.g. Project Orion
             | "realistic" estimates). Alpha Centauri is relative close at
             | 4.something ly, but other "potentially habitable/useful"
             | star systems are way out there.
        
               | sha256kira wrote:
               | Agreed. The great filter and collapse theory in general
               | are fascinating in theory and can motivate some great
               | positive action but they can't undermine the fact that
               | humans beings are doing better than they've ever done in
               | our history by almost every imaginable metric.
        
               | amanaplanacanal wrote:
               | Plus humans are extremely adaptable. Even before we
               | invented agriculture, people had colonized the whole
               | planet, except for Antarctica. It would be hard to kill
               | us all off.
        
               | not_jd_salinger wrote:
               | > humans are extremely adaptable
               | 
               | This is a strange claim I see repeated over and over, but
               | it has very little evidence to justify it. The only piece
               | of evidence people present is:
               | 
               | > people had colonized the whole planet, except for
               | Antarctica
               | 
               | This is true of a fairly large number of organisms on
               | Earth.
               | 
               | On top of this humans have only been around for ~200,000
               | years, that's not long at all. Humans have not survived a
               | single mass extinction event.
               | 
               | So far we've seen humans travel around a planet that has
               | been relatively stable for that period of time. There
               | have been plenty of species that have traveled around
               | with us that didn't even need to rely on extra tools,
               | clothing or the use of energy to survive.
               | 
               | Humans share several vulnerabilities with other megafauna
               | that have all gone extinct. A major one is a fairly long
               | gestation, plus small number of offspring per generation.
               | Human young likewise need tremendous amounts of care and
               | energy to raise to mature adulthood. Additionally human
               | have fairly high energy requirements to support their
               | complex brains.
               | 
               | We've seen exponential rise in human population only
               | because humans have had access to excessive amount of
               | non-renewable, high-energy density sources of energy.
               | 
               | It just happens that humans have lived on a planet that
               | has mostly been within survivable temperature changes,
               | with historic climate changes happening on time scales
               | that lead to easy migration. As you pointed out, the one
               | continent that does not have an environment that supports
               | human life remains empty.
               | 
               | Humans can't survive a wet bulb temperature of 35C. Until
               | just recently we never saw that temperature on this
               | planet. As we see more and more places reach that
               | temperature more often, I suspect we'll see how frail
               | human adaptability is.
        
               | Corazoor wrote:
               | In comparison to most other mammals (including the
               | neanderthals), we are pretty awesome at adaption.
               | Probably even better than bacteria, all things
               | considered.
               | 
               | That is because we possess multiple different ways of
               | adapting to our enviroment:
               | 
               | genetic
               | 
               | during childhood
               | 
               | acclimatization
               | 
               | culture and technology
               | 
               | This link provides a nice summary:
               | https://www2.palomar.edu/anthro/adapt/adapt_1.htm
        
               | edgyquant wrote:
               | > his is true of a fairly large number of organisms on
               | Earth
               | 
               | Is it though? How many other large, multicellular,
               | organisms live on every continent without humans having
               | brought them there?
        
               | zabzonk wrote:
               | Seals. Birds.
        
               | nradov wrote:
               | But we don't see the same species of seals or birds
               | everywhere. There are different species which evolved to
               | survive on each continent. Whereas humans are a single
               | worldwide species.
        
               | edgyquant wrote:
               | Birds migrate from one place to the other they don't live
               | on every continent all year round. Even if we take these
               | though (and as the other commenter said they aren't the
               | same species in every continent) that still leaves a
               | total of 3 out of how many thousands, millions, of
               | multicellular organisms on the planet.
        
               | not_jd_salinger wrote:
               | > the fact that humans beings are doing better than
               | they've ever done in our history by almost every
               | imaginable metric.
               | 
               | That's because we have had ready access to insanely
               | abundant high-energy density source of energy.
               | 
               | The non-fossil fuel supported carrying capacity of the
               | planet for humans is estimated to be somewhere around 1
               | billion people. When the fuel runs out (if we don't cook
               | ourselves first), that will collapse.
               | 
               | It is nothing intrinsic about humans that have lead to
               | our recent success, just access to lots of nearly free
               | energy.
               | 
               | edit: why the downvotes? Is there even anything
               | controversial in these statements? HN's fear of bad news
               | is getting out of hand.
        
               | myrmidon wrote:
               | What is your source for the 1 billion estimate? Because
               | that seems completely, non-credibly *low* to me.
               | 
               | I also strongly believe that we could cover _all_ our
               | energy needs with renewable sources within a few decades
               | if we really wanted to (even assuming no significant
               | advances in tech), and this seems mostly non-disputed to
               | me (because that is literally what nation-states are
               | currently planning /doing).
               | 
               | > Is there even anything controversial in these
               | statements?
               | 
               | Yes. Your statements seem not credible to me and you cite
               | no sources.
        
               | not_jd_salinger wrote:
               | 1 billion is a rough estimate based populations prior to
               | the massive boom in the industrial revolution that saw
               | massive changes in the way agriculture is done. It could
               | easily be 2 billion or so, but definitely not 7.8
               | billion. You can see the population history here[0.]
               | 
               | To see the powerful impact of fossil fuels on carrying
               | capacity you'll notice there's an important inflection
               | point around 1920-1930. This is because of the advent of
               | the Haber process[1] which allows us to use fossil fuels
               | to create nitrogen based fertilizers.
               | 
               | Lest you doubt the impact of the Haber process just look
               | at trends in corn yield per acre since then [2]. It's
               | truly remarkable. Additional gains there are from other
               | industrialized, fossil fuel driven agricultural process.
               | 
               | The Haber process _requires_ hydrocarbons. In the
               | wikipedia article you can see that it consumes 3-5% of
               | the worlds natural gas production and 1-2% of the global
               | energy supply.
               | 
               | We have completely disrupted the natural nitrogen cycle
               | [4] and so would be unable to produce anywhere near as
               | much food without fossil fuels. Because we have disrupted
               | this cycle it's not even obvious that we could go back to
               | a world of pre-fossil fuel agriculture.
               | 
               | So those are just some bit of information about my claims
               | but let's take a look at yours:
               | 
               | > we could cover all our energy needs with renewable
               | sources within a few decades if we really wanted to...
               | this seems mostly non-disputed to me
               | 
               | This is _wildly_ disputed, and I don 't know anyone who
               | credibly believes this without invoking "magic" future
               | technology.
               | 
               | For starters we haven't replaced fossil fuels with
               | "renewables" at all so far. We've just used them to
               | supplement our energy needs. You can see here [4] that
               | global fossil fuel consumption has continued to rise.
               | 
               | Then it is important to separate electricity from the
               | more general subject of energy. Currently only 20% of
               | global energy usage is electricity generation [5]. So
               | even if you replaced the entire grid with renewables over
               | night you would still be missing the vast majority of
               | energy demands.
               | 
               | We currently have no viable pathway for renewable energy
               | in transportation. Alice Friedman has more notes on this
               | than I could ever fit in a comment [6]. Transportation
               | inherently requires high energy density fuels, and
               | outside of passenger vehicles, battery technology does
               | not have the density required for industrial shipping.
               | 
               | It worth looking at our national energy flows to get a
               | good sense of just how little of the energy we use comes
               | from renewables [7].
               | 
               | But even if we look just at the electrical grid, in the
               | US, we have some very obvious problems with "all" our
               | needs. As you probably know, wind and solar are
               | intermittent power sources that requires fossil fuel
               | powered "peaker" plants to provide energy in down times.
               | 
               | This had two problems. One you need energy storage
               | technology that we do not currently have (you cannot use
               | grid scale lithium batters, pumped hydro has geological
               | constraints, molten salts only work with concentrated
               | solar, compressed air requires decommissioned oil field,
               | etc).
               | 
               | The other problem is that even if you had perfect storage
               | you need to now more than double the total energy
               | production so you can fill those batteries.
               | 
               | The should be enough sources for you to get started, but
               | I have feeling I'll still get down votes and "hand wavy"
               | explanations of how it will all work out.
               | 
               | 0. https://en.wikipedia.org/wiki/World_population#/media/
               | File:W...
               | 
               | 1. https://en.wikipedia.org/wiki/Haber_process
               | 
               | 2. https://www.agry.purdue.edu/ext/corn/news/timeless/Yie
               | ldTren...
               | 
               | 3. https://en.wikipedia.org/wiki/Human_impact_on_the_nitr
               | ogen_c...
               | 
               | 4. https://ourworldindata.org/grapher/global-energy-
               | substitutio...
               | 
               | 5. https://www.iea.org/reports/world-energy-
               | outlook-2019/electr...
               | 
               | 6. https://www.resilience.org/resilience-author/alice-
               | friedeman...
               | 
               | 7. https://flowcharts.llnl.gov/content/assets/images/char
               | ts/Ene...
        
               | myrmidon wrote:
               | Thanks for explaining how you arrived at your numbers.
               | 
               | > I have feeling I'll still get down votes and "hand
               | wavy" explanations
               | 
               | Let me turn this around: you are getting downvotes (not
               | from me) because _your_ 1 billion population carrying
               | estimate in a post-fossil age is _implausible_ and
               | borderline disingenuous:
               | 
               | 1) It assumes that pre-industrial agricultural output is
               | the maximum that our planet can sustain. Which is
               | completely off for a multitude of reasons:
               | 
               | - Genetic improvements to cultivars still fully apply
               | 
               | - Pesticides won't cease to exist
               | 
               | - Automation in harvesting/monitoring also won't go away
               | 
               | 2) There is no reason to assume that we're _anywhere
               | close_ to peak sustainable agricultural output, neither
               | in pre-industrial times NOR now.
               | 
               | 3) Furthermore, it implies that land utilization,
               | cultivar choice and consumer behavior in general would
               | stay similar/comparable regardless of cataclysmic change
               | in supply/demand (pricing). Which is obviously wrong: If
               | avocado price went up to 50$/kg then people would just
               | put potatoes on their toast instead, and total
               | agricultural output (in calories) would "inexplicably"
               | increase.
               | 
               | Regarding power:
               | 
               | Renewables (solar/wind) are a perfectly fine source of
               | primary energy. Storage/grid stability does not depend on
               | "technology we do not currently have"--Batteries and
               | inverters are perfectly usable, mature technologies--but
               | right now slapping down natural gas plants is simply
               | cheaper. This is exclusively a matter of price/ROI, and
               | installation could be jumpstarted immediately if there
               | was the political will to pay for it (and thats not
               | blaming politicians exclusively to be clear--average
               | citizen is simply unwilling to pay 1$/kWh right now for
               | residential electricity).
               | 
               | > Renewable energy in transportation
               | 
               | Friedman selfdescribes as "energy sceptic" which is
               | already...unfavorable... to me and after stumbling over
               | "running out of fossils is gonna solve climate change
               | better than anything else" (transcribed), I gave up on
               | the author completely;
               | 
               | Viable pathways are:
               | 
               | - Batteries
               | 
               | - Biofuel
               | 
               | - Fuel cells
               | 
               | - Hydrogen in combustion engines
               | 
               | We literally _built_ all of those already, but same story
               | here: It 's less cost efficient than burning diesel right
               | now, so why would anyone do it.
        
             | beervirus wrote:
             | On a long enough time line, the survival rate for everyone
             | drops to zero.
        
               | arthurcolle wrote:
               | I am Jack's existential dread
        
             | delecti wrote:
             | Sure _eventually_ , but there's no clear indication if
             | that's 10 years away, 10 billion years away, or a mere
             | technicality as our descendants evolve into something that
             | counts as a separate species.
        
               | not_jd_salinger wrote:
               | We're currently undergoing the largest mass extinction
               | event that will easily rank in the top 6 of life on this
               | planet and could possibly compete with the end-permian.
               | What makes you think we could possibly survive? Because
               | we're the cause? Plenty of species in the past that have
               | caused extinction events also perished.
               | 
               | It seems far more questionable to assume we _won 't_ risk
               | extinction in the geological near term. The parent is
               | downvoted more out of existential fear rather than an
               | honest assessment of the situation.
        
               | delecti wrote:
               | I think the parent comment was downvoted because it's not
               | really contributing anything besides pessimism.
               | 
               | As for us, I don't doubt the likelihood of a serious mass
               | extinction, including possibly a severe drop in human
               | population, but I can't see it being so severe as to
               | cause an existential threat to us. No other species on
               | this planet has had the ability to change the environment
               | to suit it, or the ease of mobility to move where they
               | can survive. Short of earth being entirely incompatible
               | with complex life on the surface, I don't see humanity
               | disappearing because of climate change.
        
               | coldacid wrote:
               | If we don't expand beyond Earth, we've got maybe 700
               | million years tops, since past then the sun's changes
               | will make multi-cellular life, if not all life, on Earth
               | impossible.
        
           | chadwittman wrote:
           | Read more about the Great Filter, it's probable it's ahead of
           | us.
        
             | riffraff wrote:
             | is it _probable_?
             | 
             | AFA we know we've been insanely lucky up to this point (as
             | earthling life we went past multiple mass extinctions, we
             | got multi-cellular life, multiple brains iterations, a
             | society which still didn't wipe itself out etc)
             | 
             | What makes it more likely for the filter to be ahead of us
             | rather than behind us?
        
               | tshaddox wrote:
               | Is it more likely that I'm immortal or that I simply have
               | thus far avoided things that would have killed me?
        
               | riffraff wrote:
               | You know that most people are not immortal, but if you
               | had no prior about the mortality of mankind it would be
               | reasonable to expect you're immortal.
               | 
               | Few people expect to die at any specific day, they just
               | know they will die at some point because mortality is a
               | given.
        
               | caeril wrote:
               | Modern civilization is _extremely_ dependent on fossil
               | fuels. We 've already passed peak conventional oil
               | production, and we're now surviving on EXTRAORDINARY
               | technical means of enhanced oil recovery.
               | 
               | If we can't make the complete transition to renewables in
               | the next thirty years, it's game over for a VERY long
               | time. Future civilizations won't enjoy the benefit of
               | Spindletop. Cheap energy sources won't be available near
               | the surface of the crust for another > 50 million years.
               | 
               | We won't go extinct, but it will be the 18th century for
               | a very long time and nobody will leave this rock during
               | that time.
               | 
               | The Great Filter is right here, in front of us, in our
               | lifetimes.
        
               | pdonis wrote:
               | _> Cheap energy sources won 't be available near the
               | surface of the crust for another > 50 million years._
               | 
               | Wrong. We already have one: nuclear energy.
        
               | caeril wrote:
               | That's a good point. It's pretty easy to construct and
               | maintain fission reactors without fossil fuels. I bet
               | enriching uranium was a snap in the 18th century, too. It
               | will be even easier even getting to the enrichment phase
               | in the future, with accessible ores about 30% as rich as
               | they were when the nuclear age began.
               | 
               | Looking forward to the fleet of electric concrete trucks
               | carrying electrically-manufactured concrete loaded with
               | batteries that were produced with lithium carbonate dug
               | out of the ground by electric excavation rigs.
               | 
               | All of this construction work will also not be disrupted
               | by any social unrest resulting from 3 billion people
               | starving to death because the Haber process no longer has
               | enough cheap feedstock to sustain modern agricultural
               | processes.
               | 
               | Thanks for educating me.
        
               | pdonis wrote:
               | Your snark is misplaced. All of the issues you raise
               | apply to _any_ source of energy, including  "renewables".
               | The difference is, "renewables" (a) are not controllable,
               | and (b) don't have nearly enough capacity to support a
               | global civilization. And if you're worried about social
               | unrest, by far the best way to ensure it is to refuse to
               | make use of an obvious source of plentiful energy to help
               | maintain and improve people's standard of living, and
               | instead insist on keeping billions of people in poverty
               | in order to satisfy your ideological preconceptions.
        
           | Moodles wrote:
           | Carl Sagan thought this, though he lived during the cold war
           | so it's not surprising he did.
        
             | hnbad wrote:
             | Considering where climate change is heading, it's
             | surprising anyone doesn't think this.
        
               | Taylor_OD wrote:
               | I agree in our case but this wouldnt be universal. Life
               | may thrive in very hot planets if their evolutionary
               | track was different.
        
               | scarmig wrote:
               | Climate change is very real and worth addressing, but
               | it's extremely unlikely to wipe out human civilization.
               | It's just going to be costly and kill millions, not
               | billions.
        
               | Pokepokalypse wrote:
               | I wouldn't say it's extremely unlikely. Maybe not the
               | primary effects won't kill us. But when nations start to
               | struggle with the primary effects, the resource shortages
               | are going to cause conflict - which will almost certainly
               | lead to wars, with these weapons, which will kill
               | billions.
        
               | ses1984 wrote:
               | Climate change by itself could be extremely unlikely to
               | wipe out human civilization but it could be the catalyst
               | that sets other events in motion like nuclear war.
        
               | miltondts wrote:
               | Extremely unlikely to wipe out all humans. I agree.
               | Current civilization, I'm not so sure. For the reasoning:
               | https://www.youtube.com/watch?v=IESYMFtLIis
        
               | darthrupert wrote:
               | Climate change doesn't have to directly kill us all. It
               | could be the trigger to something else that does.
        
               | hnbad wrote:
               | Can you clarify what you mean by "millions"? The Syrian
               | civil war is estimated to have killed just short of half
               | a million people. The pandemic easily has a global death
               | toll of roughly 4 million people so far. The Chalisa
               | famine of 1783/1784 is estimated to have killed 11
               | million people. The Spanish flu killed at least 17
               | million people, though some of the more dramatizing
               | estimates place it closer to 100 million. According to
               | some researchers, climate change is already killing
               | 100,000 a year[1]. So I assume you're not thinking of
               | just seven or eight digits unless you're exceedingly
               | optimistic.
               | 
               | Climate change will make parts of the world inhabitable
               | that are currently populated by humans. It will also
               | result in crop failures, which will cause famines. In
               | some cases formerly native crops will no longer be
               | supported by the changing local climate or farmland may
               | become completely unusable. Potable water will become
               | harder to source. Water contamination is a source of many
               | deadly diseases.
               | 
               | Even if we assume most of the deaths will be concentrated
               | in places like Africa or the Indian subcontinent, the
               | global economy relies on these places for resources and
               | cheap labor. People in ongoing climate catastrophes also
               | don't tend to stay put and die in an orderly fashion,
               | they become refugees or riot against their governments.
               | Things can get politically messy even in the nations next
               | door as humans tend to be uncomfortable with political
               | chaos and mass deaths.
               | 
               | But unlike the Spanish flu, or the potato famine, or
               | COVID, climate change is not a temporary blip that
               | happens and then goes away. If all the carriers of the
               | plague have died, nobody dies from the plague unless they
               | get infected handling the dead. Famines can starve
               | millions to death but once there's another harvest the
               | survivors have food again. Climate change isn't like
               | that. If climate change creates a drought, that's not
               | just a drought, that's now dry season and it will be dry
               | season every year from now.
               | 
               | There are currently 7.8 billion humans. There's
               | absolutely no reason to believe climate change can't kill
               | billions, especially once it's managed to kill the first
               | hundreds of millions.
               | 
               | Keep in mind that it's not about "addressing" climate
               | change. It's not a moldy bathroom tile that you need to
               | clean up or replace before the mold spreads everywhere.
               | It's a fire our entire way of life is fueling every
               | single day. We know what needs to be done to slow it down
               | to survivable levels (or at least levels that are lethal
               | for less than 1% of us) but we can't just pass
               | legislation or appeal to personal responsibility to do
               | that because it involves changes that would be economical
               | suicide for anyone doing it alone. The world economy is
               | playing a game of chicken with each other and nobody is
               | bluffing.
               | 
               | [1]: https://grist.org/climate/how-many-people-has-
               | climate-change...
        
               | catillac wrote:
               | New equilibriums will form. Where it was once one
               | climate, another will be, and the native crops that can
               | no longer live in the first climate will be supplanted by
               | new ones that can survive in the new one. This won't be
               | the case everywhere, but this sort of adaptation will
               | happen. You're talking as if everything will remain
               | static except the climate.
               | 
               | Additionally, the entire worlds population at relatively
               | sparse city density (say, Houston) can fit in like 1/3 of
               | the United States.
               | 
               | That isn't to say that climate change isn't a big deal.
               | It is one of the biggest deals and quite grave. But you
               | don't really propose any solutions. What you allude to
               | though won't happen, that everyone works together to
               | address the issues. My speculation is that if our
               | technology doesn't progress fast enough, billions will
               | die, but if tech does happen to progress fast enough then
               | that will be mitigated.
               | 
               | That isn't to say that the world couldn't use a strong
               | reduction in population. But given that we are causing
               | this, I feel particularly bad for the wildlife whose
               | habitats will be unlivable to them through no fault of
               | their own and not through natural processes.
        
           | bob33212 wrote:
           | Civilizations are only detectable for a short period of time.
           | Once they understand physics, they no longer need radio waves
           | or Dyson spheres or to travel through what we call spacetime.
        
             | yreg wrote:
             | Why wouldn't they need megastructures and travel once they
             | understood enough physics?
        
               | bob33212 wrote:
               | Space and time may be emergent, we don't know, all we do
               | know is that our current model of physics is missing
               | something. Quantum Gravity for example and We don't know
               | what happens inside a black hole either.
        
               | yreg wrote:
               | That's a non-answer though.
               | 
               | Do you mean they are guaranteed to discover another
               | "realm" and move to it?
               | 
               | Why? It might not be possible, no matter how much physics
               | one knows. Or do you take the Fermi paradox itself as a
               | proof of the solution?
        
               | bob33212 wrote:
               | Yes, it seems that the Fermi paradox implies that other
               | civs progress beyond what we consider signs of
               | intelligent life. The great filter seems less likely as
               | we get close to colonizing other planets, and then other
               | solar systems.
        
               | AnimalMuppet wrote:
               | I question your use of "implies" there. It implies no
               | such thing. What you suggest is one possible answer,
               | nothing more.
        
               | cogman10 wrote:
               | Yup, to me it implies a darker problem, that FLT is
               | something that can't be surpassed. All civs might advance
               | to that understanding and decide to maybe just occupy
               | nearby solar systems and nothing more.
               | 
               | We may not talk to them simply because it's both
               | incredibly expensive and will yield nothing more than
               | "Yup, we're stuck here, so are you".
        
               | yreg wrote:
               | Why wouldn't they send out autonomous
               | research/exploration vessels? At a sufficient tech stage
               | it's trivial.
        
               | cogman10 wrote:
               | Sure, they could, but imagine they are 10,000 light years
               | away. Such a craft would need to travel for a long time
               | before it could communicate back it's findings.
        
           | aetherson wrote:
           | Short lived on those timescales, yes. But not necessarily
           | short lived in terms of our perspective.
           | 
           | If we imagine that in the last 5 billion years, there have
           | been a good solid 10,000 post-industrial civilizations, and
           | each of those civilizations has lasted 10,000 years (in the
           | post-industrial stage where they're detectable), then that
           | implies that of the last 5,000,000,000 years, 100,000,000 of
           | them have been host to a post-industrial civilization: a
           | given year has on average 0.02 currently present
           | civilizations in it.
           | 
           | Now, this hypothesis does probably imply that significantly
           | interstellar civilizations are impossible, since it seems
           | like if you've colonized say 20 stars, what disaster could
           | possibly end your civilization?
           | 
           | (I think the most likely scenario is that we're the only
           | civilization ever to have developed in the Milky Way.
           | Everything else seems like it assumes a lot of additional
           | stuff.)
        
             | miltondts wrote:
             | > if you've colonized say 20 stars, what disaster could
             | possibly end your civilization?
             | 
             | Unfortunately, war with another civilization.
        
               | xwolfi wrote:
               | But maybe war is a territorial animal's instinct and once
               | we have shaken up a bit more of our animality, we'd
               | understand this makes no sense ?
               | 
               | If we can control resource, exchange knowledge and
               | techniques, and reproduce automatically (for instance if
               | we become small electronic machines rather than the
               | current inefficient chemical process we are), "war" might
               | probably sounds both ridiculous and totally ineffective,
               | both to cull us if we're abstract enough, and to cull
               | potential enemies, probably just as impossible to reach
               | "physically".
        
               | ithkuil wrote:
               | OTOH animals evolved those instincts because they worked
               | in the game-theoretical circumstances that competition
               | with other animals.
               | 
               | Perhaps we can shake off many emotional components of war
               | (which would make war an irrational option in many of the
               | cases that our monkey brain would have been dragged into)
               | but that doesn't necessarily mean that war itself would
               | be eradicated
        
               | mLuby wrote:
               | Animals are stuck in local maxima (betrayal in the
               | Prisoner's Dilemma). A more evolved group might discover
               | and be able to reach the global maximum (solidarity in
               | the Prisoner's Dilemma). Imagine if tigers or sharks
               | developed pack hunting, or the octopus became more pro-
               | social.
               | 
               | Also, multi-species symbiotic relationships are quite
               | common in the animal kingdom. It would be surprising if
               | that weren't true at other scales (and if it were limited
               | to the sci-fi trope of "worker species, soldier species,
               | leader species").
        
               | fiftyfifty wrote:
               | If the stars are reasonably close together a supernova
               | would do it. Even a relatively distant supernova (like
               | 30-40 light years) would likely render most planets
               | inhabitable for a long time.
        
               | aetherson wrote:
               | I mean, maybe. Honestly hard for me to imagine war
               | actually going on between two interstellar civilizations.
               | But even if it did, it seems like in 99% of all cases,
               | that would leave at least one of the two civilizations
               | still around. We're looking for explanations, in this
               | hypothesis, that leave 98% of all time with no
               | civilizations.
        
               | kadoban wrote:
               | Maybe war between two spacefaring civilizations is too
               | "easy". eg something like: throwing asteroids at ~the
               | speed of light is necessarily a cheap thing to do once
               | you're at that level, and everyone just dies.
               | 
               | Like if on Earth nukes were something everyone could cook
               | up in their backyard in an afternoon, we'd all be gone
               | pretty quick.
               | 
               | Not sure that really makes any sense though.
        
               | tjalfi wrote:
               | > Maybe war between two spacefaring civilizations is too
               | "easy". eg something like: throwing asteroids at ~the
               | speed of light is necessarily a cheap thing to do once
               | you're at that level, and everyone just dies.
               | 
               |  _The Killing Star_ [0] and _Flying to Valhalla_ by
               | Charles Pellegrino are based around the idea that it 's
               | natural for a species to annihilate all other sentient
               | species. The characters define three rules that an alien
               | species may be operating by.
               | 
               | Rule 1. Aliens will believe their survival is more
               | important than our survival.
               | 
               | Rule 2. Wimps don't become top dogs.
               | 
               | Rule 3. Aliens will assume that the first two rules apply
               | to us as well.
               | 
               | [0] https://tvtropes.org/pmwiki/pmwiki.php/Literature/The
               | Killing...
        
               | Supermancho wrote:
               | Given the relative emptiness of observed space, im not
               | convinced that a civilization A would try to annihilate
               | all life but would maybe war with others in their light
               | cone who threaten civA goals/expansion. If you can
               | traverse interstellar space you can probably make home
               | most anywhere further reducing the amount of potential
               | conflict.
        
               | kadoban wrote:
               | How likely does it seem that if you can traverse
               | interstellar space, your civilization splinters over time
               | and your potential for internal conflict just grows
               | without bound?
        
               | pharke wrote:
               | If you can traverse interstellar space you are pretty
               | much required to "live off the land" as you go and
               | especially so once you reach your destination. This means
               | you possess the ability to produce all of the energy,
               | food, material, etc. required for a civilization to exist
               | from what is present in either interstellar space or a
               | solar system. If we put our sci-fi hats on we can imagine
               | a perfect system of recycling and matter conversion that
               | can keep a massive generational ship functioning with the
               | only input being hydrogen scooped from the space it
               | crosses. If you possess that level of sophistication then
               | you really could live anywhere. That gives you plenty of
               | living space with little motivation to pre-emptively
               | attack others.
        
               | babelfish wrote:
               | Spoilers for The Dark Forest and The Remembrance of
               | Earth's Past Trilogy below.
               | 
               | In the book that the OP article is based on, humanity is
               | doing anything and everything to prevent/defend
               | themselves against an alien invasion happening ~400 years
               | in the future. The character who coins "Dark Forest"
               | theory in the book proposes sending a 'spell' (just a
               | signal containing coordinates) to a nearby star, which is
               | then amplified throughout the universe via "Sci-Fi
               | science". This reveals the location of the star, and
               | shortly after the star is destroyed by some comet-sized
               | object moving at the speed of light. It's later revealed
               | that some other civilization listens for broadcasts on
               | every spectrum, decodes them for coordinates, then
               | destroys the ones that seem to have actually been sent by
               | intelligent life.
               | 
               | I thought this made perfect sense - why wouldn't another
               | intelligent species do this if they possess the
               | technology? I personally agree with "Dark Forest" theory
               | and think that we should /never/ make first contact (lest
               | we are destroyed), but if we were to attempt first
               | contact, we should at the very least have a weapon like
               | you described available to us first.
        
               | pharke wrote:
               | > why wouldn't another intelligent species do this if
               | they possess the technology?
               | 
               | I think the only question we can ask here is "Would we do
               | this if we possessed the technology?". We only have
               | ourselves as an example of intelligent life.
        
               | 6510 wrote:
               | Ours always rot from the inside out.
        
         | ManBlanket wrote:
         | There's the other end of a technology curve, when a
         | civilization ceases use of an outdated piece of technology. In
         | our case humanity is looking for radar because we're currently
         | broadcasting it. Why would anyone continue using radar to
         | communicate within a few years of quantum entangled data
         | processing, capable instantly transmitting data instantaneously
         | across vast distances? There might be a few living that rock
         | star lifestyle of HAM radio operation and messenger pidgeons,
         | but at that moment our civ would go narly completely dark to
         | our sister civ's SETI program. All humanity's existence so far
         | has been nothing but spark swallowed up by the darkness of
         | time. Our use of radio a fart in the wind.
         | 
         | This theory is incredibly type-zero-civ-pocentric. A species
         | capable of interstellar travel will have mastered technologies
         | we can't even comprehend. By the time humanity is able to
         | meaningfully reach across the stars, we'll have spread life
         | across our entire solar system and everything we'd ever need.
         | Unlimited energy from our sun, a lush and verdant Venus and
         | Mars, mining colonies across the solar system producing vast
         | quantities of any desirable element, not to mention an Earth
         | whose biosphere is a shining jewel - perpetually locked-in at
         | peak biodiversity.
         | 
         | Begs the question of what we would ever need from another civ,
         | and furthermore what a similar civilization would ever want
         | from a bunch of squatting troglodytes such as ourselves.
        
           | tyfighter wrote:
           | That's not possible. (https://en.wikipedia.org/wiki/No-
           | communication_theorem)
        
         | anyonecancode wrote:
         | This makes sense to me. I feel we're in a small room peeking
         | through a tiny hole in the wall and asking why the outside
         | world is so empty.
        
         | magneticnorth wrote:
         | And to add the evidence we do have; in the billions of years of
         | life on earth, there has only been <200 years where any species
         | had the will and the way to send deliberate communications into
         | space. Observational evidence suggests that the time span of
         | civilizations existing is vanishingly tiny compared to the
         | vastness of time overall
        
         | pharke wrote:
         | This is the L constant of the Drake equation. Probably the
         | hardest to find a value for until we've actually discovered
         | other intelligent life or remains of such. The confounding part
         | of it is that we can only guess at things that may end a
         | civilization so completely that it will never recover. Things
         | like the so called Great Filters, natural extinctions like
         | impact events or gamma ray bursts, or other more speculative
         | things that prevent expansion. The tricky part is that our
         | existence seems to fly in the face of such events so far, is
         | that mere luck or do all forms of intelligent life have enough
         | sense to navigate around these problems? The last and most
         | paradox defining part of the problem is that even if the
         | tiniest fraction of civilizations can evade these filters then
         | they should eventually be everywhere in the galaxy. Assuming
         | the Copernican principle that we are not at a special place in
         | the universe or time then there should have already been ample
         | opportunity for such civilizations to develop and hence Fermi's
         | question "Where is everybody?".
        
           | kryogen1c wrote:
           | > Great Filters, natural extinctions like impact events or
           | gamma ray bursts
           | 
           | you know what really alarms me? these things are only chances
           | on a very, very short-time scale. they are inevitable, yet no
           | one seems alarmed when meteors come between us and the moon
           | and we dont see it coming until hours beforehand.
           | 
           | sun bursts blowing out the electric grid, nuclear war,
           | antiobotic resistance, crop and animal monoculture, climate
           | change, natural resource depletion... taleb is right. we need
           | an agent of chaos to make anti-fragility valuable. otherwise
           | we learn the lesson the hard way. by dying.
        
             | TrainedMonkey wrote:
             | > you know what really alarms me? these things are only
             | chances on a very, very short-time scale. they are
             | inevitable, yet no one seems alarmed when meteors come
             | between us and the moon and we dont see it coming until
             | hours beforehand.
             | 
             | That is why Elon is so hell bent on making humanity multi
             | planetary.
        
               | tsimionescu wrote:
               | Elon Musk has the same chance of making humanity multi-
               | planetary as the Pharaohs did. We are still far away from
               | any semblance of a chance to do so.
               | 
               | Besides, anything at all that we can imagine hitting the
               | earth (except a gamma ray burst or collision with another
               | planet) would still leave the earth in a better shape
               | than Mars is. It's entirely doubtful that humanity could
               | be self-sustaining on Mars even in principle, it is
               | certainly not possible with known technologies.
        
               | EthanHeilman wrote:
               | >It's entirely doubtful that humanity could be self-
               | sustaining on Mars even in principle, it is certainly not
               | possible with known technologies.
               | 
               | Citation needed.
               | 
               | What's the blocker here?
               | 
               | Energy production on Mars? Why not Solar or Simple
               | Stirling Engines.
               | 
               | Food/Closed ecological systems? Hard, for sure yeah, but
               | even not particularly well funded small ecosystems like
               | Biosphere2 worked for several years.
               | 
               | The biggest issue seems psychological.
        
               | lisper wrote:
               | > What's the blocker here?
               | 
               | Human nature, apparently. Just about all large-scale
               | human activities at the moment are predicated on
               | exponential growth. We're nowhere near achieving a long-
               | term stable steady-state here on earth. The odds of
               | achieving that in a vastly more hostile environment are
               | even lower.
        
               | hutrdvnj wrote:
               | Well, but Pharaohs couldn't shoot a car into space.
        
               | lmohseni wrote:
               | I don't think Elon could build a pyramid. He might be
               | capable of tweeting about one though.
        
               | iseanstevens wrote:
               | He could certainly get a pyramid built. And that is the
               | best you can do.
        
               | zokula wrote:
               | Elon Musk will use child slave labor to build a Pyramid.
        
             | aeturnum wrote:
             | I think people _are_ alarmed, but solutions to these
             | problems are enormously costly and largely fictional. The
             | techniques we have for living in space (or transiting
             | through it) would not sustain us if we lost earth. They are
             | enormously costly[1], which is fine for what we are doing,
             | but we need multiple orders-of-magnitude improvement to be
             | practically interstellar.
             | 
             | On balance, I think we could spend more, but I also think
             | diminishing returns is very real. Giving the wright
             | brothers 100,000 workers to build copies of their planes
             | would not have gotten us to the space shuttle much faster.
             | Ironically, it could have slowed us down because of sunk
             | cost fallacies.
             | 
             | [1] https://twitter.com/sim_kern/status/1411304471934685184
        
               | e40 wrote:
               | > I think people are alarmed
               | 
               | I think your view is skewed. Every single person I've
               | talked to about this as looked at me like they are bored.
               | Of course, here on HN, I've found many like-minded
               | people. That's great, but I think very few humans,
               | especially humans in the power structures that run this
               | planet, care about this issue.
        
               | aeturnum wrote:
               | > I think your view is skewed
               | 
               | I suspect it's more that we have different definitions of
               | how widely a feeling of alarm should spread before saying
               | this. I agree the absolute number of people who are
               | worried about the problem is small.
               | 
               | I guess I think about it in terms of "what proportion of
               | the population that would be directly involved in solving
               | this problem"? I would suspect that is close to 100%.
               | Anyone involved in space work is aware that we may we
               | wiped out and would not like that to happen. Government
               | leaders are also, I think, aware, but unconvinced that
               | more resource expenditure would be meaningfully helpful.
               | Given how difficult it's been to convince people to deal
               | with a much cheaper & easier problem that is much more
               | obvious and immediate (global climate change) I have
               | trouble critiquing people for being insufficiently
               | zealous about this issue.
        
               | mikevin wrote:
               | I think that's a pretty healthy reaction, pretty much all
               | of human history took place in an environment where
               | investing time an energy in thinking/caring about "the
               | big picture"/"distant future" would drastically lower
               | your chances of survival. Even today there's still plenty
               | of people who have to worry about having something to eat
               | tomorrow.
               | 
               | We're slowly getting comfortable enough about our
               | immediate situation, leaving room to start thinking on a
               | bigger scale. But I think it takes actual effort to say:
               | "ok brain, I understand our immediate situation is
               | important but I think we've got that covered enough to
               | allow us to start caring about the less immediate
               | problems we might face"
               | 
               | I'm a glass half full guy so maybe it's naive but I think
               | we're actually doing pretty well. Climate change sucks
               | and we're pretty slow to respond but you wouldn't expect
               | a hunter/gatherer to be able to see the importance of
               | fighting it. Our situation is different but the brain
               | isn't all that different when it comes to prioritizing
               | things to spend time/energy on. Obesity is a good example
               | of what happens when you combine ancient instincts with
               | modern situations.
               | 
               | Same thing probably goes for racism. We're advanced
               | enough to know better and responsible for our actions but
               | we're dealing with a brain has evolved mostly during
               | times where trusting other tribes and survival of the
               | fittest were Incompatible. Xenophobia had some
               | evolutionary benefit and now we have to deal with it's
               | existence in a vastly different situation.
               | 
               | Like I said, people should know better and have to be
               | held responsible for their actions and we should never be
               | comfortable with the slow rate of change. Still I like to
               | remind myself every now and then that its amazing how
               | much progress has already been made changing things that
               | evolution hasn't had time to value yet.
               | 
               | This turned out way longer than I expected but it's
               | something I think about a lot. Hope you don't mind me
               | using your comment to finally put some thoughts into
               | words.
        
         | 0-_-0 wrote:
         | It's much easier to traverse 1 year in time then 1 light year
         | in space though
        
           | toufka wrote:
           | Is it? I can move all sorts of distances, in different
           | directions, at all sorts of rates. It's surely harder to go
           | certain speeds than others, and in certain directions than
           | others. But to move 1 year in time - I only have one speed
           | and one direction to move.
        
         | ryandvm wrote:
         | That and the fact that civilizations probably only broadcast EM
         | radiation out into the void for a short period of time before
         | they start getting into energy efficiency and switch over to
         | more efficient communication technologies.
        
           | snowwrestler wrote:
           | I have heard (can't remember the source) that radar,
           | especially military radar, continues to be a significant
           | source of artificial-looking EM radiation leaving the Earth,
           | even as radio and TV broadcasts have declined in power.
        
           | cogman10 wrote:
           | This is my theory.
           | 
           | You look at human civilization and that's exactly what's
           | happened. We started off by broadcasting everything as loud
           | as we could (which isn't very loud) and we've slowly
           | transitioned to signals that are both quieter and don't
           | really survive escaping the atmosphere.
           | 
           | I can't imagine an advanced species wouldn't follow a similar
           | communications path. The only way we detect them is if they
           | specifically target our spot in the sky with focused EM for a
           | very long time, generations! After all, they have no clue
           | when we would be in our evolutionary path.
           | 
           | And for that to happen, the species would have to first find
           | us. Not just find us, find us while we are still listening.
           | 
           | And this is all with the assumption that FTL
           | communication/observation is even a possibility (It likely
           | isn't).
           | 
           | IMO, the simplest answer is that FTL communication and travel
           | is impossible. Advanced civilizations across the galaxy have
           | all come to the same conclusion.
           | 
           | We might be able to explore our own neighboring stars
           | throughout generations but it's unlikely we'll be able to
           | ever send a message to another civilization that will get
           | there while they are listening (without spending huge amounts
           | of power).
        
             | xwolfi wrote:
             | But if you pursue an evolution over millions of years, at
             | some point we'll have to miniaturise. Imagine we can make
             | fully conscious silicon - let's say in 200 000 years (6500
             | human generations). At this point, we'd be tempted little
             | by little to raise them as our intellectual children and
             | find less and less need to make them with sperm and vagina.
             | 
             | After a long while, there might be this great replacement,
             | totally peaceful, that would lead these conscious organisms
             | with a vastly superior intellectual efficiency to probably
             | become very small and self centered and not behave like the
             | territorial monkeys we are. What do you think a massively
             | singular electronic intelligence will think when it notices
             | a planet like ours ? "nuke them all and rape their women" ?
             | This is monkey behavior that we still haven't fully shaken
             | up.
        
           | giantrobot wrote:
           | Even broadcast emissions aren't detectable at long distances.
           | If you parked an Arecibo-class telescope in orbit around
           | Alpha Centauri the only signals you'd detect coming from
           | Earth would be _intentional_ directional transmissions from
           | an Arecibo-class (or Goldstone class) radar.
           | 
           | Our television and radio broadcasts aren't detectable by an
           | Arecibo-class telescope out much past Jupiter let alone
           | outside the solar system. Even our high powered radar systems
           | wouldn't be detectable out even half a light year from the
           | solar system.
           | 
           | The only civilizations that can be detected with a SETI-like
           | program would be ones intentionally transmitting directional
           | signals. Even then out past a thousand light years even a
           | multi-terawatt (EIRP) signal would be difficult to detect.
           | 
           | Like inverse square law is as unforgiving as the rocket
           | equation. Anyone hand-waving either of those principals is
           | not trying to have a meaningful discussion about interstellar
           | communication or travel, they're just writing about science
           | fiction.
        
             | nikhilgk wrote:
             | > Even then out past a thousand light years even a multi-
             | terawatt (EIRP) signal would be difficult to detect.
             | 
             | Not necessarily. Gravitational lensing may enable directed
             | communication at much lower power levels :
             | https://storkpaulo.wordpress.com/2010/04/26/gravitational-
             | le...
        
               | giantrobot wrote:
               | Leaving the serious engineering difficulties involved in
               | a solar gravitational lensing system aside, such a system
               | doesn't necessarily help in picking up just random
               | omnidirectional broadcasts from an ETI.
               | 
               | Say we had an SGL telescope positioned such to image an
               | Earth-sized planet we know is in orbit of Alpha Centauri
               | A. For ease of math we'll say this Earth sized planet is
               | at a distance such the solar constant is the same as
               | Earth. So that's a total power received from the Sun of
               | 1.74x10^17 watts and with the Earth's mean albedo of 0.3
               | about 5.22x10^16 watts being reflected off into space.
               | 
               | We can use our SGL to image the planet around Alpha
               | Centauri because it's reflecting 52.2 _peta_ watts of
               | sunlight out into space. So it takes the power of a star
               | reflecting off a disc with a cross sectional area of
               | 1.26x10^8 square kilometers for a proposed SGL system to
               | detect and image a planet.
               | 
               | The amount of power an omnidirectional antenna can
               | possibly emit is somewhat less than 52 petawatts.
               | Broadcast antennas output at most a few _mega_ watts EIRP
               | because there's no utility in blasting out hundreds of
               | megawatts for terrestrial transmission. Such broadcasts
               | just aren't going to be detectable even with
               | gravitational lensing from our Centauran neighbors.
               | 
               | Nor are gravitational lenses terribly useful for beacons
               | since you need the right geometry between the sender,
               | star, and receiver to use the lens. You could use lensing
               | to increase the EIRP of your transmission but only at a
               | specific target. Nobody outside the focal plane of the
               | lensing system is going to benefit from the lens.
               | 
               | SGLs are a neat idea and an interesting topic but I don't
               | think they solve many SETI problems.
        
       | pklausler wrote:
       | Over enough time and space, probabilities other than 0 and 1
       | become rare; i.e., things that are not impossible become
       | inevitable.
       | 
       | Bracewell-von Neumann self-replicating interstellar probes are
       | not impossible. I think we're not too far away from being able to
       | create and launch them ourselves, if we survive.
       | 
       | Has any technical civilization in galactic history launched a BvN
       | probe? It only takes one launch of a BvN probe to saturate the
       | galaxy for all time afterwards, esp. if they can mutate and
       | compete. But we don't see any such probe activity, and I think
       | that we would, if they were busily mining asteroids and
       | frantically manufacturing copies of themselves. So I think we can
       | tentatively assume that nobody has launched one yet in our
       | galaxy; and explaining that possibility leads to some unsettling
       | consequences.
        
         | captainmuon wrote:
         | I'm not convinced von Neuman probes are actually feasible. For
         | one, you'd need general artificial intelligence because the
         | task of setting up a production line on a different planet is
         | incredibly complicated. Then you'd need to move a _lot_ of mass
         | across star systems. Tiny replicators are not going to survive
         | the harsh conditions on other planets, and then find and
         | extract all the resources you need to build bigger machines. I
         | 'm not sure what the minimum feasible probe would be, but I
         | guess a lot bigger than everything we can send into space now.
         | 
         | Finally, I'm not sure interstellar flight is realistically
         | possible. Especially if you are not sending solar sails or rice
         | corn sized probes, but a payload the size of an oil rig or
         | bigger.
        
           | pklausler wrote:
           | I don't think that planets are good targets; you'd want to
           | use asteroids for raw materials and stay in microgravity, no?
           | 
           | But yes, if BvN probes are impossible at any level of
           | technology, that would explain their apparent absence.
        
       | shadowlight wrote:
       | Fermis paradox is garbage.
       | 
       | He can't make such a statement about probability when the
       | circumstances aren't even known.
       | 
       | We don't even know how life forms so how can we even know what
       | the probability of it forming is?
       | 
       | How do we know that probability is high enough that it is very
       | likely to occur? The chances of it occurring could be incredibly
       | low.
        
       | hindsightbias wrote:
       | For those that believe that intelligent life should be more
       | common within the Milky Way, some author had a good response to
       | that:
       | 
       | It only takes one xenophobic von-Nuemann capable civilization to
       | ruin the party for everyone.
        
       | overthemoon wrote:
       | Call me naive, but the fact that we're still sending messages
       | makes me happy in spite of the grim calculations.
        
       | jlpom wrote:
       | Maybe I lack imagination, but I can only see as a constant
       | selective pressure leading to a specie with interstellar space
       | plans (we still haven't) the biped-on land evolution that took
       | place on earth, and I can only see earth-like planet hosting
       | avanced life.
        
       | elihu wrote:
       | Something to consider about "Dark Forest" scenarios is that
       | there's no particular reason to think that a given species would
       | be more benevolent towards its own kind than some other alien
       | species.
       | 
       | If you think about how humans behave, I think if we ever get to
       | the point where we're a multi-planetary species, those two
       | planets aren't going to trust each other very much. If we expand
       | to other star systems with years of communication lag, it'll be
       | even worse -- both societies are going to be constantly expecting
       | a hail of nukes to fall out of the sky one of these days, unless
       | there's either a plausible defense against such an attack, or a
       | reasonable expectation of mutually-assured destruction.
        
       | cletus wrote:
       | Anyone interested in this topic should spend some time on Isaac
       | Arthur's series about the Fermi Paradox. There's an episode on
       | this called Hidden Aliens [1]. It's a flawed idea.
       | 
       | If you assume that we live in an FTL universe subject to the laws
       | of thermodynamics (as I do), mass and energy (being basically the
       | same thing as we know) are the ultimate limiting factor. This
       | basically means bigger is better. Remember such a civilization is
       | likely thinking on time lines where a trillion years is a blink
       | of an eye.
       | 
       | So how will a spacefaring civilization evolve? Likely into a
       | Dyson swarm for three primary reasons:
       | 
       | 1. It requires no new physics. It's essentially an engineering
       | problem that only requires materials as complex as stainless
       | steel and energy tech no more complex than solar power. If you
       | get better tech (eg fusion, graphene for construction) this
       | outcome becomes more likely not less;
       | 
       | 2. Orbitals are a highly efficient way of creating living area. A
       | full Dyson swarm around our Sun would likely consume <1% of the
       | mass of Mercury, for example; and
       | 
       | 3. The energy output of the Sun is essentially "free".
       | 
       | A full Dyson swarm makes you a Kardashev-2 (K2) civilization. On
       | the Carl Sagan scale, that means you're consuming ~10^26 Watts of
       | power. And that's just for one Sun. Now consider:
       | 
       | 1. Such a civilization is capable of sterilizing the galaxy in
       | 100,000 years if they choose to;
       | 
       | 2. There's really no hiding from such a civilization;
       | 
       | 3. There's really no hiding a Dyson swarm from a Dyson swarm from
       | an advanced civilization due to the IR signature it would
       | produce. This has nothing to do with say radio communications.
       | 
       | Remember with the Fermi Paradox you don't have to establish what
       | the average civilization does. Say there are 5 spacefaring
       | civilizations in the Milky Way. What are the odds that all of
       | them hide? Now imagine there are 100. The odds of them all hiding
       | are much lower. And it only really takes one who decides to build
       | Dyson Swarms and expand beyond their star to be detectable.
       | 
       | So I can imagine a splinter of a civilization decides to "hide".
       | A good example of this would be if fusion becomes viable. One
       | could sink habitats into Neptune, which is not particularly
       | dense, and probably live there undisturbed and unfound for eons
       | is quite high. That's probably more hidden than, say, trying to
       | hide between stars.
       | 
       | It's just not likely that as the number of civilizations
       | increases that all of them go that route.
       | 
       | My view is that spacefaring life is just quite rare. We may well
       | be the only one within out light cone within the Milky Way. Why
       | that is is an interesting topic.
       | 
       | [1]: https://www.youtube.com/watch?v=tEBn8bc0k-I
        
       | markus_zhang wrote:
       | Although I very much enjoy the novel, I think Vlad's theory is
       | more likely to be true:
       | 
       | https://www.youtube.com/watch?v=o9kbcGfX35M&ab_channel=Peter...
       | 
       | As of myself, I also have a theory why it's difficult for
       | civilizations to see each other:
       | 
       | 1 - You need very advanced technology to break through the
       | barrier of speed of light (worm hole, someone?)
       | 
       | 2 - Such advanced technology will need a long, continuous period
       | of peace and prosperity for researchers to figure it out. Wars
       | are "useful" in certain way but not always.
       | 
       | 3 - Intelligent beings are in general greedy (regardless of their
       | biological construction) and they want to take as much resources
       | as possible.
       | 
       | 4 - The resources in the universe is unlimited, but the resources
       | that one civilization can obtain is very limited.
       | 
       | 5 - Combine 3 & 4, you can probably figure out that the "long,
       | continuous period of peace and prosperity" is very much unlikely
       | and very likely to be broken by wars within the civilizations.
       | 
       | 6 - The more advanced the civilizations they are, more likely
       | those wars will wipe them out completely.
       | 
       | 7 - Even if they managed to avoid those destructive wars
       | (unlikely already). Another factor we need to consider is the
       | number of smart scientists and technicians that can figure out
       | and implement those fancy technologies.
       | 
       | 8 - Yeah for sure, one man, such as Newton or Einstein can leap
       | forward our understanding of the universe.
       | 
       | 9 - But you need a very large of population to "grow" one Newton
       | or Einstein.
       | 
       | 10 - Go back to 3 & 4, now tell me, even if they manage to avoid
       | wars, can they also avoid creating a caste and shut everyone else
       | out of a prosperous life? I mean look at ourselves.
       | 
       | 11 - If such thing happens (eventually), there is not going to be
       | enough population to create a Newton or Einstein. And
       | science/tech eventually just don't go forward.
       | 
       | 12 - Combine 6 & 11, it is really very, very unlikely for any
       | civilization to develop advanced technology to travel beyond the
       | speed of light, which also means we don't get to see them (very
       | often).
        
       | tener wrote:
       | The Dark Forest makes so many (explicit and implicit) assumptions
       | it starts to feel extremely dodgy. There are also falacious
       | arguments embedded within it which fail to imagine numerous
       | possible scenarios simply by following "tried and true" paths
       | copy-pasted from sci-fi novels.
       | 
       | TLDR: The forest analogy fails because civilizations are not
       | singular entities (like animals are) but rather complex
       | structures which can merge and evolve. The supposed technological
       | and societal barriers can very well not materialize in which case
       | the theory falls apart.
       | 
       | Details below...
       | 
       | > Suppose a vast number of civilizations distributed throughout
       | the universe, on the order of the number of observable stars.
       | Lots and lots of them.
       | 
       | "On the order of observable stars" is extremely wide. Perhaps
       | there is one life-bearing planet per galaxy. Perhaps there is one
       | per 100 stars. Those are vastly different outcomes.
       | 
       | > Survival is the primary need of civilizations.
       | 
       | On individual level humans have no hope to "survive" (i.e. live
       | immortal lives). Yet despite that fact we don't commit mass
       | suicide. The "primary need" of human civilization to survive is
       | merely emergent behaviour due to other factors. Perhaps advanced
       | civilizations would be happy to achieve some grand undertaking
       | and then perish.
       | 
       | Now for the second "axiom":
       | 
       | > Civilizations continuously grow and expand ...
       | 
       | Expansionist civilizations with unlimited space certainly can do
       | that. But does it really bring any benefits? The more complex the
       | societal structure, the harder it is to change. Perhaps there is
       | a critical mass above which it becomes detrimental to multiply
       | beyond and all "sane" civilizations will stay below it.
       | 
       | > ... , but the total matter in the universe remains constant.
       | 
       | It may be finite, but perhaps most of it will be "stranded"
       | anyway - so far away that access to it becomes non-feasible
       | anyway.
       | 
       | > ... In other words, the finite nature of resources will
       | ultimately pit one civilization against another as they all
       | struggle to sustain their growth.
       | 
       | This part I believe is the biggest logical fallacy of all. What
       | is civilization if not a set of societal structures? And we can
       | easily imagine merging of two such structures - they are already
       | composed of other structures; what is just another level of
       | complexity? If we merge two "competing" civilizations suddenly we
       | have a single larger civilization... supposedly without conflict?
       | The amount of resources is the same as before but not we only
       | have a single contender: the merged civilization.
       | 
       | This paradox stems from the failure to account for the internal
       | race for resources inherent to all civilizations. The
       | civilizations are not unitary entities. Treating them as such and
       | assuming blind dedication to it from its members is short sighted
       | and lacking imagination.
       | 
       | > If open communication exists, then conflict could be averted
       | and tensions diffused. But given the time-lag involved with any
       | attempt at interstellar communications, civilizations that are
       | light-years apart are unlikely to resolve their fears quickly.
       | 
       | Sufficiently advanced civs can simply send AI envoys or do mind
       | upload of their representatives with the speed of light. This
       | makes the learning of language, communication etc. very quick.
       | Perhaps FTL communication can exist too. Etc. etc. Endless ways
       | to break another assumption.
       | 
       | > By the time they arrived, the attacker's technology would not
       | have matured one bit, while the defender would have decades or
       | centuries to progress.
       | 
       | It may be possible that advanced technology does not progress as
       | fast as it does now. See our experiments with fusion and particle
       | accelerators. What used to be easy now takes years and billions
       | in funding. Perhaps going at some point getting any kind of
       | advancement will be nearly impossible and all technology will
       | become "old". In this scenario the centuries of technological
       | advancement are moot. OTOH potential gains from trade from
       | foreign civs is very real possibility.
        
         | yreg wrote:
         | I agree with your other critisising points but I think
         | presumptions (2) and (3) make sense somewhat.
         | 
         | It's safe to assume that for any self-replicating life
         | evolution takes place, universally. The genes (no matter on
         | their biological implementation) are always evaluated by one
         | fitness function only - whether they succeed in spreading
         | around.
         | 
         | Life isn't optimised for surviving per se, but it is optimised
         | for replicating.
         | 
         | The same in a way applies for civilisations. The ones that are
         | bad at expanding are massively outexpanded/outnumbered by the
         | ones that are good at expanding. Unless expanding fundamentally
         | always leads to civilisation's downfall (but I don't see how it
         | would?)
        
           | dfilppi wrote:
           | I suspect that any advanced species would abandon life as
           | soon as possible. E.g. become non-biological and immortal.
           | Then interstellar travel is trivial.
        
             | yreg wrote:
             | That makes sense, but machines and culture(s) still undergo
             | evolution, unless replication and changes (mutations) are
             | prevented. (Again, the ones that are good at spreading are
             | more prevalent.) What do you think?
        
         | AlgorithmicTime wrote:
         | >Expansionist civilizations with unlimited space certainly can
         | do that. But does it really bring any benefits? The more
         | complex the societal structure, the harder it is to change.
         | Perhaps there is a critical mass above which it becomes
         | detrimental to multiply beyond and all "sane" civilizations
         | will stay below it.
         | 
         | If even one civilization were expansionist in the history of
         | our galaxy, we would expect the whole place to be full of their
         | descendants. Evolution works that way.
        
       | godshatter wrote:
       | I wonder if we're making too many assumptions about how
       | civilizations would live and spread. I've always wondered why our
       | species puts so much focus on planetary colonization instead of
       | building smaller habitats. We seem to assume we'll terraform
       | Mars, maybe build habitats on some of the Jovian moons, then jump
       | to the next star. It seems more logical to me to take the ISS and
       | iterate on it, building larger habitats and learning how to live
       | in them.
       | 
       | There could be trillions of habitats out there and we'd never
       | know it. From small low-orbit stations orbiting home planets to
       | larger complexes orbiting their stars instead up to generation
       | ships moving to the next star to mine for more resources or to
       | build more ships due to population limits being hit. Once you've
       | perfected the building of habitats that are large enough and are
       | tailored to your species specific needs, why mess around with
       | planets that can kill you in so many different ways?
       | 
       | Maybe the reason we don't see anyone is because we can't resolve
       | even very large habitats at light-year distances and the reason
       | we don't run into them is because we don't have anything they
       | can't get somewhere that isn't already inhabited. Perhaps they
       | avoid inhabited systems because of the dangers involved.
        
         | Coriolis3 wrote:
         | I agree, for an advanced species space habitats seem far
         | superior to planets. A constant supply of free energy (solar),
         | easy access to endless metal (asteroids), no
         | earthquakes/tsunamis/volcanos/wildfires. If we're talking far-
         | future, to me the Culture and their Orbitals represent the
         | ideal utopian endpoint for humanity.
        
       | NiceWayToDoIT wrote:
       | In the near future it is more likely we will wipe out ourselves
       | either due to Nuclear War, Global Warming, rogue AI or similar,
       | than some hostile alien civilization will get us. It seems that
       | we are those hostile aliens for ourselves.
        
         | [deleted]
        
         | myrmidon wrote:
         | Do you think there is a "real" (>1% over the next century) risk
         | for humanity to wipe itself out, or just that the hostile-alien
         | risk is way beyond negligible in comparison?
         | 
         | Because all current climate doom-erism notwithstanding--
         | humanity extinction seems impossible to achieve to me via
         | climate change or nuclear war; rogue autonomous self-
         | replicating systems might be a danger, but are too far beyound
         | current tech to estimate risk IMO...
         | 
         | Very curious if/how/why you disagree on this!
        
           | hnbad wrote:
           | We don't need to go extinct. Our global economy is very
           | fragile, relatively speaking and it's not at all clear we
           | could sustain the economy necessary to perform space
           | exploration if bad things happen.
           | 
           | To avoid an extended argument about all the ways in which
           | climate change will screw things up, let's focus on nuclear
           | war: a nuclear war between, say, India and China would not
           | only wipe out huge swaths of the human population but also
           | ruin the global economy because industries in Europe and the
           | US depend on these countries. And that's without going into
           | the ecological effects of a nuclear war.
           | 
           | The economy relies on layers and layers of extremely
           | convoluted supply chains and can't sustain a loss of even 1%
           | of the human population, let alone 10% or more. The US has
           | only seen a death of around 0.2% of its population due to
           | COVID and is already facing labor shortages in retail. The
           | blockade of the Suez canal was a big concern but imagine the
           | Suez canal is simply gone.
        
             | pharke wrote:
             | Those convoluted supply chains are a recent phenomena. Some
             | international trade is necessary but large countries like
             | the United States are capable of producing almost
             | everything they require domestically. Trade is only
             | preferable if you can import something for less money than
             | you can manufacture it locally.
        
             | joshuahedlund wrote:
             | > The economy relies on layers and layers of extremely
             | convoluted supply chains and can't sustain a loss of even
             | 1% of the human population
             | 
             | I think you are underestimating the ability of humanity to
             | adjust and innovate, especially over time. I mean we
             | literally essentially lose 1% of the human population to
             | old age every year.
        
           | NiceWayToDoIT wrote:
           | Just a feeling or rather educated guess is:
           | 
           | That general AI going rogue if it gets conscious is small,
           | more probable is narrow AI that has mistake in setting goals,
           | given too much power by either military or corporations.
           | 
           |  _Global Warming_ is highly probable but we still have chance
           | if we find energy to cooperate around mutual goal. Key
           | points:
           | 
           | - Siberian permafrost and releasing huge amount of CH4
           | topping up all efforts.
           | 
           | - Amazon forest now release more CO2 than sequester (this
           | week news)
           | 
           | - Species are being extinct on a rapid rate
           | 
           | - Wildfires/droughts continue to increase devastation
           | 
           | - Floods and heatwaves are stronger (losing ice caps will
           | increase this to Equatorial heats once planet albedo of caps
           | is lost )
           | 
           | Now, critical is next 10 years That does not mean that
           | humanity will be wipe out in 10 years, but will set course
           | for final destination. As no technology or amount of money
           | will help us past that point, weather pastern and issues will
           | be out of our hands. In bad scenario 99% reduction of
           | population till 2100. Again guess. Underground pocket of
           | sparse scientific communities could survive bit longer past
           | this point, using geothermal energy and nuclear power.
           | 
           |  _Nuclear war_ is quite probable, I think critical is next 20
           | years: https://www.thedrive.com/the-war-zone/41421/pentagon-
           | warns-o... If all weapons are fired, simply put, some people
           | may survive, but they would wish they are dead. Let me put
           | this way, we all have romantic dreams of surviving, go to
           | Hiroshima, ground zero, then straight to museum, and then
           | imagine something 2000 times more powerful multiplied by
           | 16000. And of course everyone forgets Nuclear power plants,
           | ~450 with similar yield. If you do not have Cheyenne Mountain
           | complex at your disposal, your life expectancy is between 0
           | and 3 years. (acid rains, nuclear winter, no food, no
           | medications, no drinking water, no animals ...). Even if
           | someone survives it would be back to stone age - killing each
           | other for basic necessities (even human meat), as there is
           | nothing else to eat.
           | 
           | China vs US, US vs Russia, India vs Pakistan, rogues nation
           | getting a weapon on some black market ...
           | 
           | Anyhow, if our civilization was cooperative society with
           | higher goals, it would be fine, but from my experience, and
           | from what I saw during my life, all governments are nothing
           | but aristocratic mafia organisation sponsored by big business
           | having one goal to increase wealth of their share holders
           | justifying all means by what ever ends they have.
           | 
           | But regardless what I wrote or how many arguments I give as
           | Friedrich Nietzsche "Hope in reality is the worst of all
           | evils because it prolongs the torments of man." many
           | especially those in power to do something, will have tendency
           | not to believe in the final outcome until it happens, so
           | instead of taking actions they will continue business as
           | usual.
           | 
           | When I was young I lived in different country there one post
           | WW2 leader used to say "Work and enjoy like we will live in
           | peace 100 of years, and at the same time prepare like there
           | will be a war tomorrow", personally I think it is a good
           | policy for Global Warming or WW3, we should imagine the worst
           | and then work as hard as possible so it never happens,
           | employing all possible strategies at our disposal to save all
           | life on planet, (DNA bank, 5d crystals, space travel, multi-
           | planet, multi-suns ... whatever).
           | 
           | Similar like in IT we protect systems, for me who ever uses
           | "doom-erisam" and similar shaming terms is nothing better
           | than those person. Ostrich burying head in the sand like will
           | not save you from the lion. In IT good network security guys
           | imagine all possible scenarios, and they are not afraid that
           | by the so called "new-age quantum vibration field" if they
           | imagine bad scenarios they will attract it just by the power
           | of thought. Admins/devs frequently must imagine and test all
           | bad scenarios, even play roles of bad actors, so they can
           | employ protective techniques.
           | 
           | In the similar way we should explore bad scenarios and see is
           | it possible to do anything, but unfortunately, we who talk
           | about it and comment a lot, our circle of concern is
           | significantly bigger then our influence, and those who have
           | huge circle of influence (money) the do not give two dimes
           | about our concerns, and that is the reason my friend I am not
           | optimist about our future in next 10 years...
        
             | myrmidon wrote:
             | > "doom-erisam" and similar shaming terms is nothing better
             | than those person
             | 
             | First: I use the term because I see NO factual basis for
             | assuming that humankind is going extinct. Your post did not
             | change my view on that:
             | 
             | 1) I fully agree that global warming is a massive problem.
             | 
             | But assuming that it's going to lead to human extinction is
             | IMO straight up _delusional_.
             | 
             | The only plausible mechanism is full-runaway "hot-venus"
             | greenhouse effect (evaporating our oceans), and that is a
             | scenario that--pretty much all scientists agree--we are NOT
             | going to reach no matter how much fossil fuel we burn (http
             | s://en.wikipedia.org/wiki/Runaway_greenhouse_effect#Eart...
             | ).
             | 
             | Rising sea levels and climate change might lead to
             | international crises and cost countless human lifes, but
             | there is simply NO WAY for this to kill ALL humans by
             | itself.
             | 
             | 2) With nuclear threats it's a similar situation: There are
             | simply not enough nukes to cover the inhabited surface
             | (even assuming worst-case full escalation!):
             | 
             | The highest estimates I found were between 1.6 and 3
             | billion victims, assuming that every last nuke was used on
             | the most effective target and killing every person there
             | (which are both completely unrealistic assumptions).
             | 
             | Both fallout and nuclear winter are completely insufficient
             | for extinction purposes, because there is not enough
             | radioactive material for the fallout and not enough dust in
             | the atmosphere for nuclear winter to kill all (we had
             | somewhat comparable volcanic events in the past).
             | 
             | 3) Corrupt leadership is something humankind has survived
             | with since leaders exist; there is simply no reason to
             | assume that they are suddenly going to cause our all
             | extinction.
        
               | NiceWayToDoIT wrote:
               | > I use the term because I see NO factual basis for
               | assuming that humankind is going extinct. Your post did
               | not change my view on that:
               | 
               | There is a huge difference between I do NOT want to see,
               | and there is NO factual basis.
               | 
               | From https://worldpopulationreview.com/world-cities only
               | 1170 cities have population of 2,179,929,822, RS-28
               | Sarmat yield is 10 heavy warheads, each yield of 1.5Mt.
               | Currently there is 3,700 nukes deployed and 13,132 nukes
               | total. We do not know what China has so those number are
               | without it. With the new hyper-sonic weapons time to
               | react and go to shelter which in London practically does
               | not exist except underground transport, so to get to
               | nearest station you would need 30 min but nuke needs 15
               | min to arrive. Let's suppose that one Sarmat is enough to
               | level town size of London or Paris. So only with firstly
               | deployed there would be 2200 nukes to spare. But what
               | about heavier nukes those 10Mt yields, what about
               | revamping Tsar Bomba with 50Mt (8km fireball, 68 km
               | mushroom cloud and shock waves circling Earth 3 times).
               | So, what exactly will intercept hyper-sonic? So when you
               | say estimate 1.6 to 3bn I would rather say it is very
               | optimistic, and that only from the blasts. Next goes
               | fallout... are you saying no one will die out cancer in
               | full exchange? It will be all ok after 5 years? EMP would
               | wiped out grid and internet, what will exactly pump
               | water? What are you going to drink? Quickly made filter
               | from charcoal and that will do? And to what hospital are
               | you going to go if you scratch on rusty nail for
               | instance? Next, what are you going to eat, 80% of food in
               | UK is imported, https://www.businessinsider.com/no-deal-
               | brexit-percentage-br... there is no more ships with food
               | and oil? Where are you going to get money banks are out,
               | no plastic cards, cash does not worth anything? do you
               | have silver or gold? How many will die out of hunger in
               | next 10 years?
               | 
               | And what about nuclear power plants 450 of them? They are
               | not the same like nukes, nukes burn their fission
               | material, but as we know from Fukushima Daiichi Accident
               | and Chernobyl disaster, they were quite tricky, and there
               | we managed to do something about it. Who will go to "fix"
               | nuclear power planets after exchange, so plenty of
               | fallout there?
               | 
               | As I said it would not be extinction but 99% reduction,
               | and those who survive would wish they have not. By the
               | way I am not trying to convince anyone people have had
               | too many video survival games with happy ending, and to
               | test reality you just need to go to near by woods for 7
               | days without food and water, and what ever experience you
               | have just multiply by 300 times.
               | 
               | Going back to first line,
               | 
               | > your post did not change my view
               | 
               | I somehow find more frighting and delusional that way of
               | thinking, as it leaves possibility to use mentioned as
               | solution for fixing problem as people optimistically
               | believe they are the one that will survive.
               | 
               | There is a reason why "Mutually assured destruction" and
               | "nuclear deterrence" exist as such, as no one will ever
               | attempt any such idiotic thing. As what we model usually
               | does not correspond with reality. And when you know that
               | everyone will loose like in the move "War games" then
               | only way to win is not to play a game. And if current
               | narrow AI can do it today I hope you as far superior
               | intelligence can come to the same conclusion.
        
               | myrmidon wrote:
               | > I somehow find more frighting and delusional that way
               | of thinking, as it leaves possibility to use mentioned as
               | solution for fixing problem as people optimistically
               | believe they are the one that will survive.
               | 
               | I'll give you the other perspective on the doom-erism:
               | 
               | People preaching about the inevitable extinction of
               | humankind just provide ammunition/"strawmans" _against_
               | progressive climate policies because these doom-
               | prophecies are obvious bullshit and everyone not in an
               | echo bubble knows it.
               | 
               | Just consider how easy it was to dismiss your "humankind
               | is going extinct because of climate change" points--
               | because it IS BULLSHIT. Climate change is NOT going to
               | lead to human extinction, and preaching this just steals
               | credibility and hinders much more than it helps by
               | polarizing society/preventing consensus.
               | 
               | As for the nuclear threat:
               | 
               | > only 1170 cities have population of 2,179,929,822
               | 
               | First: These are metropolitan areas, not cities. One
               | warhead per area is not even going to kill a fraction of
               | the people.
               | 
               | Consider: Tokyo metro region is 14000 km^2. Fireball size
               | for a 10Mt warhead is <20km^2 (no larger warheads are in
               | use and there would be no point). The highest estimate I
               | found (3E9 victims) assumed 3 warheads per region I
               | think, which is pretty similar to the numbers you came up
               | with.
               | 
               | Taking all the aftereffects into account, you'll maybe
               | get past the 50% population mark, but that is still not
               | human extinction.
        
               | NiceWayToDoIT wrote:
               | > Just consider how easy it was to dismiss your
               | "humankind is going extinct because of climate change"
               | points-
               | 
               | You have to understand that you have not dismissed
               | anything, you do not have knowledge you have beliefs,
               | judging by the angry typing. There is no point discussing
               | with believes.
               | 
               | Regarding full fledged nuclear exchange I would ask you
               | to write a paper and make computer model, I do not know
               | what is your field of work do you have a sufficient
               | knowledge to do it?
               | 
               | Regarding Global Warming it is fairly uncharted
               | territory, now we know that models from 10 years ago were
               | overly optimistic and that things are happening at much
               | faster rate than expected.
               | 
               | Anyhow, to cut the long unfruitful story short, lets
               | remember this and check in 5 and 10 years what happens.
        
           | colinmhayes wrote:
           | If civilization as we know it ends but humanity survives it
           | would be very difficult for future generations to reestablish
           | because we've used up all the easy to access hydrocarbons.
           | Without easy to reach coal there won't be another industrial
           | revolution and humanity would be stuck for millions of years
           | until the hydrocarbons reform.
        
             | NiceWayToDoIT wrote:
             | That is some kind of Oil centric thinking that got us in
             | this mess in the first place. Renewables and fusion can do
             | the much better better job at any point. By the way coal
             | will not form ever again, only reason why coal/oil formed
             | is because bacteria has not learned how to decompose
             | cellulose at the time.
             | https://www.nationalgeographic.com/science/article/the-
             | fanta...
        
               | pharke wrote:
               | I believe that theory is no longer valid. It was
               | supposedly fungus that feeds on woody plants that
               | resulted in a drop in lignin rich coal but that doesn't
               | seem to quite work out. Coal is formed when there's a lot
               | of organic matter that gets trapped in an oxygen poor
               | environment and then buried and compressed over time.
               | That process is certainly still happening though not at
               | the same rate it has in the past. This article has some
               | good details https://arstechnica.com/science/2016/01/why-
               | was-most-of-the-...
               | 
               | There's still quite a lot of coal though.
        
               | colinmhayes wrote:
               | I don't think renewables and fusion will be an option in
               | a post apocalyptic society. After a few generations of
               | anarchy the knowledge will be lost.
        
               | NiceWayToDoIT wrote:
               | True, solar and nuclear need a bit more tech, but wind
               | and hydro are quite simple they need a bit of wire,
               | magnet and something to spin.
        
             | myrmidon wrote:
             | I disagree on this, because biofuels are a viable
             | substitute in almost every situation.
             | 
             | I'm fairly certain that our accumulated knowledge would
             | make a second industrial happen even faster _in spite of_
             | fossil-fuel-lack (but it might play out slightly
             | differently, because of higher fuel costs...)
        
               | ThrowawayR2 wrote:
               | Doubtful that there's enough biofuels to produce high
               | quality steel in large quantities and that's a pre-
               | requisite to a post-apocalyptic neo-Industrial
               | Revolution. Only coal burns hot enough and was available
               | the huge quantities necessary.
        
               | myrmidon wrote:
               | Sure, producing iron without coal sucks; but there is
               | already enough scrap metal around to power several
               | additional industrial revolutions, and an arc furnace is
               | really simple, especially if already know how electricity
               | works beforehand.
               | 
               | Long term, there are alternative routes that could be
               | taken (capable of processing fresh ore) but using scrap
               | metal just seems easier/more likely to me.
        
         | EamonnMR wrote:
         | The universe could still be a dark forest of AIs ready to smash
         | each other as soon as they spot each other.
        
         | yreg wrote:
         | Do you think that most/all civilisations end this way before
         | becoming spacefarers?
        
           | NiceWayToDoIT wrote:
           | I don't think, or rather I hope there are civilization that
           | as a part of their evolution had cooperation, sharing,
           | exploration and innovation embedded as main and prevalent
           | strategies of survival and thriving. I would like to think
           | that there is as in magic fairy tails of old, civilization
           | where good prevails. Where leaders (or what ever mechanism of
           | decision they have) and those in power - are not easily
           | corrupted as here.
        
             | hnbad wrote:
             | You're describing humans. Up to the point where you hope
             | their leaders aren't corruptible. The problem with humans
             | mostly comes down to centralization. We're an extremely
             | cooperative species until we're put in an environment that
             | promotes competition and punishes cooperation.
             | Centralization of power is one such environment. And it's
             | very hard to undo at this point.
        
               | NiceWayToDoIT wrote:
               | https://www.youtube.com/watch?v=rStL7niR7gs Corruption is
               | not just leaders it is a network of beneficiaries, like a
               | snake with thousand heads, and regardless how many you
               | cut new will grow. And we do not know how to get out of
               | that mold. And democracy in uneducated society simply
               | does not work. And we do not have it. All governments are
               | aristocracies. News media displays of "busting"
               | corruption is just "bread in circuses" of this age, media
               | manipulations of wide populous while business as usual
               | continues, hypnosis of population by spin offs and
               | demagogues narrative.
        
           | chadwittman wrote:
           | It's a common proposed solution to the Great Filter idea.
        
       | jmull wrote:
       | I love that series -- just an incredible, imaginative, unique
       | perspective -- but the dark forest hypothesis just doesn't make
       | sense.
       | 
       | It's orders of magnitude of orders of magnitude less energy to
       | communicate with (including obscuring your origin, if you want)
       | than destroy a civilization. And communication has potential
       | benefits (cooperation) that destruction does not.
       | 
       | Civilizations that communicated would very quickly and easily
       | out-compete/out-advance civilizations that did not. "Malevolent"
       | civilizations would inevitably run into more advanced cooperating
       | civs sooner or later and be checked, either learning to cooperate
       | themselves or lose.
       | 
       | Put another way, the assumptions used to build out the
       | hypothesis, "Chains of Suspicion" and "Technological Explosion",
       | don't make sense either. "Chains of Suspicion" assumes
       | civilizations _cannot_ communicate, yet the dark forest
       | hypothesis assume civilizations can destroy each other. That 's a
       | contradiction. If you can physically interact, you can
       | communicate (and as I pointed out before, with much, much less
       | energy/resources than it takes to destroy). And "Technological
       | Explosion", as written in the book, assume exponential
       | technological growth could occur at any point, which seems to be
       | nonsense to me. Any kind of exponential growth necessarily
       | depends on a medium primed with the resources for that growth and
       | stops when the resources are expended (which is never all that
       | long, given the nature of exponential growth).
       | 
       | I cringed every time this idea was forced into the forefront of
       | the books. They are such great and imaginative books, I don't
       | mind at all that not all the ideas really pan out, but it was a
       | little hard to stomach every time the plot turned on this weak
       | idea.
        
         | luckyandroid wrote:
         | > "Chains of Suspicion" assumes civilizations cannot
         | communicate, yet the dark forest hypothesis assume
         | civilizations can destroy each other > If you can physically
         | interact, you can communicate
         | 
         | I think you misunderstood what they meant by "communicate".
         | They don't mean "reach with a message", they mean "engage in
         | back and forth communication with both sides understanding the
         | conversation".
         | 
         | We're still struggling to talk to dolphins, but technically we
         | could nuke them all to death if we ever got scared they were
         | rising up.
        
           | xwolfi wrote:
           | But we're not struggling to talk to dolphins, they're
           | struggling to materialize Shakespeare. We understand their
           | structures and concerns more than they understand ours, and
           | we observe them when they're still in the original soup.
           | 
           | ALl this to say: if they were rising up, we'd probably be
           | able to create a bidirectional connection. We can only make
           | sense "nuking them all to death", like you say in america to
           | mean "defend our freedom and way of life", if we are able to
           | communicate and are faced with a refusal to submit. The
           | dolphin, so far, accept american hegemony - there's no
           | purpose to nuking them.
           | 
           | So it is correct what you say, but here we're talking of
           | civilizations. Civilizations worth nuking will always have a
           | way to understand each others, otherwise there'd be no threat
           | worth suppressing.
        
         | artimaeis wrote:
         | I also adore the series. It's become my favorite sci-fi I've
         | read in years.
         | 
         | You're leaving out the time required to communicate. Yes,
         | communication would require less energy, but time is a constant
         | that even type 3 civilizations could be in short supply of.
         | 
         | The chain of suspicion calls this out explicitly, it's not that
         | the civs cannot communicate, it's that due to the extreme
         | lengths of time required for back-and-forth communications
         | their societies are likely to significantly change during
         | communications, leading to higher probability of the
         | technological explosion.
         | 
         | What medium was primed for the technological explosion on Earth
         | since the industrial revolution? I mean, I reckon we could
         | point to an array of things that have seemed as though they
         | would be a limit, but thus-far we've always found ways past
         | that (see: peak oil). I'm not trying to indicate I think our
         | trends _will_ go on forever, just that it seems possible they
         | could.
        
         | obedm wrote:
         | I think dark forest is the best explanation so far.
         | 
         | If what you say is true, it should've been true for earlier
         | human civilizations too.
         | 
         | Why didn't the Chinese and Japanese civilizations unite to
         | conquer others?
         | 
         | Why didn't the Mongols unite with whoever else to conquer,
         | instead of Genghis Khan doing it all with a bunch of Mongols in
         | horses?
         | 
         | Human civilization is a dark forest that only changed with
         | global trade. The communication challenge is language and
         | culture. And civilizations have always been technologically
         | distinct, with the more powerful one almost always conquering.
         | 
         | With interstellar communication and technological advance it
         | would be orders of magnitude higher stakes.
        
           | pharke wrote:
           | Each of those civilizations you mentioned rose to the heights
           | of their power by uniting multiple smaller tribes into one
           | larger civilization.
        
             | obedm wrote:
             | You've got a fantastic point. It reminds me of Chinese
             | history, full of war between clans until it was finally
             | United.
             | 
             | What I keep thinking about is that we are all... Humans.
             | Like, the same animal, same way of thinking etc. And yet
             | our answer so many times is conflict.
             | 
             | The only reason conquerors didn't kill all the conquered
             | was for taxes and slaves and so on. Imagine if resources
             | were not an issue ( advanced enough tech) and you wanted to
             | avoid confrontation.
             | 
             | Sending a near light speed bullet to explode a star seems a
             | good trade-off to keep your dominance.
        
           | aeternum wrote:
           | Historically it's extremely rare that the conquerors killed
           | everyone in the cities they conquered. Instead they enslaved
           | some, or let them mostly live and just taxed them. Even with
           | other species that regularly attack humans (tigers or even
           | mosquitos), we have not exterminated them.
        
             | obedm wrote:
             | We're trying our best to exterminate certain species of
             | mosquitoes. We haven't done it because we lack the
             | technical ability as of yet.
             | 
             | Also, have you met any Aztec? There are barely any American
             | Indians left compared to the millions there were
             | originally.
             | 
             | Mammuts? All the giant marsupials of Australia that went
             | extinct the moment humans set foot there?
             | 
             | We've been on top of the food chain for very long. Now
             | imagine if we discover another race may take our place and
             | the only option is communication or total obliteration?
             | 
             | I wish it was different, we only have a sample size of one.
             | 
             | But just like the three space ships that first found out
             | about the dark forest and ultimately killed each other,
             | it's what makes most sense from game theory
        
             | Mary-Jane wrote:
             | Not many neanderthals around these days. Just an
             | observation.
        
               | pharke wrote:
               | We carry them with us in our genes, that seems to
               | indicate more than just war was going on.
        
               | obedm wrote:
               | We don't know that happened to them, or to any other
               | human species for that matter.
               | 
               | But we're pretty sure we obliterated a entire species in
               | our way up the food chain ( giant marsupials for example)
        
         | [deleted]
        
         | Florin_Andrei wrote:
         | > _They are such great and imaginative books_
         | 
         | Those books are pretty awful. They can't make up their mind
         | whether they belong to sci-fi or fantasy. Sometimes they veer
         | towards hard scifi but then make naive mistakes with current
         | science. The characters are cardboard cutouts, very shallow,
         | and make nonsensical decisions. The general atmosphere is
         | depressing and ends in the complete failure of basically
         | everything.
        
       | PicassoCTs wrote:
       | Even with a dark forest, one would have territorial threats
       | announced to the rest of the world.
       | 
       | Examples: Blow a star up and make it project a unique territorial
       | mark. Make a diamond lighttower, beaming threatening messages to
       | probable green zones, to lure unsuspecting enemies in.
        
       | nestorD wrote:
       | My favorite answer to Fermi's Paradox is a paper (which I do not
       | have on hand) showing that it can be explained by the
       | approximation error in doing a raw product of probabilities.
       | 
       | If, instead of doing a product of the probability of each event,
       | you actually take the various distributions into account
       | (nowadays you can easily test a wide variety of distributions
       | with monte carlo methods) then, the probability of getting into
       | contact with another life in the universe becomes vanishingly
       | small.
        
         | [deleted]
        
         | pdimitar wrote:
         | What would that be a "favorite" answer? It's just one of the
         | hypotheses. Drake's equation and how exactly must it be applied
         | has been fiercely discussed for decades.
         | 
         | Unless, of course, saying it's your "favorite" is your way of
         | saying "I like to believe in this one hypothesis".
        
           | nestorD wrote:
           | It removes the paradox without requiring additional
           | hypotheses, just refining the math. That makes it the most
           | convincing solution to the paradox for me.
        
         | jeremysalwen wrote:
         | My interpretation of that paper is that it is saying "We don't
         | have hard enough bounds on the parameters of the Drake
         | Equation, so one (or more) of the parameters could be much
         | lower than expected". But without specifying which parameters
         | are much lower than expected, the paper is just saying "our
         | current understanding/uncertainty about the universe is
         | consistent with someone solving the drake equation in some
         | unknown way at a later point in the future". Which I don't
         | think is actually a solution. The real question we are
         | interested in is _which_ parameters are lower than expected and
         | _why_.
        
         | taejo wrote:
         | I guess this is the paper you're talking about:
         | https://arxiv.org/abs/1806.02404
        
       | lowbloodsugar wrote:
       | Peter F. Hamilton's Salvation series [1] has a similar take, but
       | also provides a possible out: don't live on planets or near
       | stars. In Liu Cixin's books (which I _loved_ btw, also SPOILERS),
       | the level of technology involves weapons that can destroy solar
       | systems. It seems reasonable that such civilizations could live
       | between the stars.
       | 
       | I don't agree that Civilizations need to expand without limit.
       | Even humans, having reached a certain level of comfort, have
       | _difficulty_ reproducing enough to maintain population levels.
       | Conceivably then, civilizations will reach a comfortable size and
       | then stop. Certainly they might be willing to stop when they
       | reach a  "boundary".
       | 
       | The problems with enemies is that, unless we are of sufficient
       | size, we might bump into an enemy that is, say, twice our size,
       | and therefore can thump us in a war. However, novels by Iain M.
       | Banks [2] and Neal Asher [3] provide insight here (Culture vs
       | Iridans, Polity vs Prador). The issue is not how many weapons you
       | have (W), or even how many weapons you can make (dW/dt), but how
       | fast you can make weapons factories (d2w/dt2) (etc). And
       | ultimately, organics simply have absolutely no chance against AI:
       | in both Culture and Polity, the AI runs the war for humans.
       | 
       | On the matter of technological breakout, the entire Lensman
       | series has an underlying theme of the back-and-forth of new
       | weapon vs it's mitigation [5]. Liu makes a good case that such
       | back-and-forth is unrealistic: in the time it takes light to
       | travel from the enemy's star to yours, they might go from poking
       | each other with pointy sticks to fusion bombs, or from fusion
       | bombs to star-killers. But there is a simple mitigation there
       | too: don't hang around stars. Or rather, think of stars as Navies
       | think of islands: nice place to refuel and R&R, but don't put all
       | your ships in one harbor.
       | 
       | Ultimately, if survival is the goal, then Salvation or We are Bob
       | [4] are the way to go: expand as much as possible. Just be
       | willing to defer to existing civilizations.
       | 
       | [1] https://www.goodreads.com/book/show/34068552-salvation
       | 
       | [2] https://www.goodreads.com/author/show/5807106.Iain_M_Banks
       | 
       | [3] https://www.goodreads.com/author/show/56353.Neal_Asher
       | 
       | [4] https://www.amazon.com/Are-Legion-Bob-Bobiverse-Book-
       | ebook/d...
       | 
       | [5] https://www.goodreads.com/series/49225-lensman
        
       | Archelaos wrote:
       | What makes the dark forest hypothesis not so conving to me is
       | that it has the presupposition that it is indeed possible to
       | hide. An advanced civilization close to us that is surveying the
       | sky for signs of life would have very likely identified earth as
       | a very promissing candidate due to the presence of methane and
       | oxygen in its atmosphere at the same time. So our star system
       | would have long been under surveillance, before we had the chance
       | to develop a technology that would reliable disguise our
       | presence.
       | 
       | If such a technology is possible at all, only the very first
       | advanced civilization had the ability to hide from all others.
       | And only if they were able to develop it before any other
       | civilization had been able to track them.
       | 
       | To some extent it might nevertheless be a reasonable strategy to
       | keep as quiet as possible. But this strategy is less and less
       | useful for the latecomers. If they were already tracked by a
       | multitude of other advanced civilization they would hardly
       | benefit from keeping quiet. Unless they (wrongly) think that they
       | are an early advanced civilization.
       | 
       | However, if a couple of these civilizations start to openly seek
       | contact to others, what can the hidden ones do? If a hidden
       | civilization starts to fight one of these latecomers, it would
       | need to leave its cover and make itself known to all other
       | civilizations in its vicinity. If it follows the dark forst
       | hypothesis, it could only do so, when it is sure that it is the
       | only dangerous civilization in its forest.
       | 
       | This leaves me with the following alternatives:
       | 
       | - The forest is dark, because there is only one civilization out
       | there that is very capable in hiding and has the ability to
       | exterminate any latecomer efficiently and without traces.
       | 
       | - The forest appears dark, because it is thinly populated and we
       | just have not looked enough for the others.
       | 
       | - We are the only ones in our cosmic vicinity.
        
         | jerf wrote:
         | I agree with your logic but would add one more thing to it:
         | There is no compelling reason to wait until a planet
         | conclusively proves it has intelligence on it to nuke it into
         | oblivion with a kinetic kill projectile. You don't really know
         | how long it will take for an intelligent species that could
         | compete with you to arise. Humans have moved pretty quickly on
         | cosmological scales, there's no particular reason to believe
         | we're moving at the max speed and a lot of reason to think
         | otherwise. Compared to the amount of energy you can obtain over
         | cosmological time periods, the expenditure of a kinetic kill
         | projectile is nothing.
         | 
         | In fact, if you don't mind waiting a bit, it can be almost
         | trivial. All you have to do is basically get a factory to the
         | target system; it can use local resources to build a kinetic
         | kill projectile efficiently out of a big, local hunks of rock
         | and local hydrogen. Launching near-light-speed projectiles from
         | lightyears away is the emergency "oh crap! They're smart
         | already!" option. Killing a planet that only has dinosaurs on
         | it is _dead easy_ for these hypothetical intelligences and
         | there 's little reason to believe they wouldn't.
         | 
         | So I think the dark forest hypothesis falls down on the fact
         | that not only has Earth been broadcasting loud and clear to the
         | stars that it has life on it ever since the Great Oxygenation
         | Catastrophe, which was somewhere around 2 to 2.5 _billion_
         | years ago, the Dark Forest theory implies that any surrounding
         | intelligence that arose and was capable of seeing Earth on that
         | time frame should have hit it. That has not happened. And 2.5
         | billion years is actually significant even on cosmological time
         | scales.
         | 
         | (Also, no, the dinosaur asteroid or other events were not kill
         | projectiles. If an alien intelligence is going to kill-
         | projectile Earth there's no compelling reason to just sort of
         | inconvenience life... it's going to _eliminate_ it.
         | Hypothesizing a race capable of launching projectiles but being
         | too stupid to realize it wouldn 't do the job is too precise a
         | level of incompetence to believe in. As they say, there's no
         | kill like overkill.)
         | 
         | Fun science fiction premise... not a solution to the Fermi
         | paradox.
        
           | jeremyjh wrote:
           | How far away from earth is it still possible to detect oxygen
           | and/or methane levels in the atmosphere?
        
             | minitoar wrote:
             | You just need enough light to do spectroscopy. I'm not
             | really aware of a limit other than being in our light cone.
        
             | jamiek88 wrote:
             | Light years with the right telescope. It's just
             | spectroscopy.
        
             | david-gpu wrote:
             | If I was a technologically advanced civilization, I would
             | send robotic Von Neumann probes around the galaxy to keep
             | tabs on things at close proximity.
             | 
             | If I was also murderous, I would have programmed the probes
             | to destroy any signs of life.
             | 
             | So, the fact that we are still alive after broadcasting the
             | presence of life through out atmosphere for the last couple
             | billion years is quite reassuring.
        
               | pharke wrote:
               | Wouldn't that be the most difficult and expensive way to
               | simply monitor for life or technosignatures? Compare that
               | to simply (relatively speaking) building massive space
               | based optical and radio observatories that can observe
               | every visible star. The light reaching you has already
               | made the trip, you just have to collect it. If you were
               | murderous, you could launch an attack from your home
               | system rather than waiting for the probes to spread from
               | system to system.
               | 
               | Granted there could be some technical limitations that
               | prevent you from observing certain systems but that pool
               | will be much smaller than an entire galaxy of stars.
               | 
               | Also, don't forget that a Von Neumann probe is at a
               | disadvantage when it arrives in a system since you want
               | to send the minimum number of probes to each star and
               | then have them replicate on arrival. If your probe
               | accidentally shows up in a system that contains an
               | advanced civilization capable of detecting and capturing
               | it then you've given away the fact of your existence and
               | your intent along with all the information that can be
               | gained by studying the probe.
        
               | mLuby wrote:
               | So have your replicators approach a system from an
               | unexpected vector; one course correction in interstellar
               | space should be enough.
               | 
               | Also I'd expect the probes would communicate with the
               | homeworld via relays (where they were replicated) rather
               | than directly, so it'd take a fair amount of effort to
               | unravel a replicator network unless you caught one of the
               | very first probes.
               | 
               | And also it'd be conspicuous if there was a volume of
               | space in your network where your probes always failed.
        
               | wait_a_minute wrote:
               | I wonder if everyone is therefore incentivized to not
               | send out such probes, then. Since no one can guarantee
               | they are advanced enough that their probe won't get
               | captured by someone more advanced who just sends back a
               | scarier probe as a thank you gift.
        
           | DonaldPShimoda wrote:
           | (Major spoilers for The Expanse below.)
           | 
           | > There is no compelling reason to wait until a planet
           | conclusively proves it has intelligence on it to nuke it into
           | oblivion with a kinetic kill projectile.
           | 
           | Or send a technologically engineered molecule that can hijack
           | single-cellular life to help establish your needed technology
           | in the target solar system.
        
             | tshaddox wrote:
             | It's funny that that wouldn't have been a spoiler if you
             | hadn't mentioned the name of the work.
        
             | jerf wrote:
             | That's a variant of what I discuss in another reply, but
             | well underscores my point of just how _easy_ this is if you
             | happen to get there anywhere in the 2.0-2.4 billion window
             | Earth has had prior to intelligence. If you colonize the
             | system in any manner, be it biological, technological,
             | whatever, for Dark Forest purposes that 's equivalent to
             | destruction; there is no longer a threat of natural
             | competing life.
             | 
             | You've got two major approaches: Fling a kinetic kill
             | projectile, or if you have the tech to get "something" into
             | the target system at roughly orbital velocities, send some
             | machines to do the job with local resources.
             | 
             | None of these things appear to have happened in Earth's
             | past. Ironically, trying to spin yarns in which they did
             | anyhow still end up countering the Dark Forest hypothesis,
             | because all such attempts must either include significant
             | probabilities of failure of the attempts or the possibility
             | that the life out there is benevolent (to some degree, at
             | least sufficient to avoid simply wiping us out, which on
             | this scale is "benevolence" despite whatever else they may
             | be doing) which itself would imply the forest isn't that
             | dark.
        
           | AnimalMuppet wrote:
           | "Too precise a level of incompetence to believe in." That's
           | the most beautiful wording I have read in some time...
        
             | jerf wrote:
             | Hat tip: https://www.shamusyoung.com/twentysidedtale/?p=615
             | "That is a very specific level of tired."
        
           | im3w1l wrote:
           | If I use humanity as a model, then we don't see other great
           | apes as dangerous competitors. Rather we see them as
           | interesting curiosities. We want them to stay alive. But it's
           | hard to resist the desire to turn their habitats into
           | something economically productive.
           | 
           | Colonizing other planets and making them into homes for
           | aliens long before a native civilization has a chance to
           | arise seems more plausible than just destroying them.
        
             | jerf wrote:
             | For the purposes of this conversation, colonizing other
             | planets effectively _is_ destroying them. After that, no
             | natural intelligent competitor will arise and surprise you,
             | because you 're right there to keep an eye on everything.
             | 
             | (Of course, you may still have any amount of conflict with
             | your fellow settlers, or your someone in your original
             | species' descendants two systems over, but that's a
             | completely different conversation.)
        
           | pharmakom wrote:
           | You don't destroy the system because you want to inhabit it
           | yourself. This assumes that life is looking for similar
           | habitats and that it's not simpler to create an artificial
           | planet anyway.
        
             | crowbahr wrote:
             | If there is oxygen breathing carbon based intelligent life
             | that wants our planet they could've easily spotted and
             | taken it anytime within the past 2 billion years.
             | 
             | It seems safe to say that there isn't life that wants our
             | planet.
        
               | wait_a_minute wrote:
               | Or they did want it and used it for seeding more complex
               | life so they could eventually create homo sapiens. Like
               | the start of the film Prometheus.
        
               | crowbahr wrote:
               | Which would mean that the dark forest is still false
               | right?
        
               | edgyquant wrote:
               | Why would anyone come from light years away to inhabit a
               | planet. It would be cheaper to just build habitats or
               | colonize a planet in their solar system. There is almost
               | nothing we can provide to a civilization capable of
               | traversing between start systems.
        
               | tjalfi wrote:
               | > Why would anyone come from light years away to inhabit
               | a planet.
               | 
               | Many motives from the age of exploration could apply -
               | imperialism, religious beliefs, religious or political
               | differences, cultural exchange, scientific discovery,
               | competition with others, etc. People don't always take
               | the cheapest option; the same could be true of aliens.
        
               | crowbahr wrote:
               | All resources are scarce.
               | 
               | But if nobody wants our world and they're scared of
               | intelligent life then just send out Von Neumann probes to
               | ensure intelligence isn't showing up elsewhere. First
               | mover's advantage nullifies the entire dark forest.
        
               | edgyquant wrote:
               | _relatively_ scarce, sure. There are millions of times
               | more of all the resources Earth has between us and any
               | civilization coming from light years away. By the time
               | they needed Earths resources they'd have to have gobbled
               | up large chunks of, if not the whole, Galaxy.
        
               | crowbahr wrote:
               | Right but the whole premise of the Fermi Paradox is that
               | it doesn't take long (on a galactic scale) to gobble up
               | the entire galaxy using STL transit if you're dealing
               | with a constantly growing civilization.
               | 
               | So either they'd - already have gotten here & already
               | have destroyed the earth when we showed intelligence OR -
               | already have gotten here & don't care about destroying
               | intelligence.
        
               | krapp wrote:
               | >So either they'd - already have gotten here & already
               | have destroyed the earth when we showed intelligence OR -
               | already have gotten here & don't care about destroying
               | intelligence.
               | 
               | Or... civilizations don't experience unbounded growth
               | over millions of years across millions of light years to
               | begin with.
        
               | edgyquant wrote:
               | Well okay but I believe that premise is flawed. It still
               | takes millions of years for one (which is a long time on
               | human timescales) and it's more likely civilizations
               | Balkanize and begin fighting each other if they even were
               | to be so resource driven they wished to colonize the
               | galaxy that quick which I don't think we have any reason
               | to believe is true.
        
               | belter wrote:
               | Or maybe that carbon based intelligent life that wanted
               | our planet it's us.
               | 
               | We were almost wiped out after the first large impact.
               | The impact that happened a few millennia after we killed
               | all those awful looking smarty octopus that lived in this
               | planet. But we could not defend against the large Comet,
               | it come from behind the Sun and way too fast. We had
               | minutes notice.
               | 
               | Some microbes survived...And here we are again typing on
               | our keyboards. :-)
        
               | tjalfi wrote:
               | The aliens in Scott Westerfeld's _Fine Prey_ invade Earth
               | for a novel reason. It 's ROT-13 (https://rot13.com/)
               | encoded to avoid any spoilers.
               | 
               | Gur nyvraf ner ynathntr areqf. Gurl bpphcvrq Rnegu fb
               | gung uhznaf jbhyq perngr n arj qvnyrpg bs gurve ynathntr.
        
         | sangnoir wrote:
         | > An advanced civilization close to us that is surveying the
         | sky for signs of life would have very likely identified earth
         | as a very promissing candidate due to the presence of methane
         | and oxygen in its atmosphere at the same time.
         | 
         | Signs of _carbon-based_ life - who is to say all forms of life
         | are carbon-based? The universe is vast, what are the odds of
         | aliens being in our vicinity and time (light cone) stumbling
         | upon our galaxy or star?
        
           | joshuahedlund wrote:
           | > Signs of carbon-based life - who is to say all forms of
           | life are carbon-based?
           | 
           | There's a limited number of elements, and their abundance in
           | the universe decreases rapidly beyond the first few. Carbon
           | is by far the most advantageous for life due to its vast
           | ability to form complex molecules. Silicon _might_ be a
           | distant second. If there _is_ other life in the universe, and
           | _if_ there 's nothing special about us, it might not _all_ be
           | carbon-based, but it 's extremely likely that a large amount
           | of it will be.
        
         | inlikealamb wrote:
         | >However, if a couple of these civilizations start to openly
         | seek contact to others, what can the hidden ones do?
         | 
         | Stay hidden or destroy anyone close enough to put you at risk
         | along with themselves. This is a spoiler, but IIRC from the
         | books the ultimate safety net was to make your solar system not
         | only invisible... but _impenetrable_ in either direction but
         | essentially trapping yourself in a black hole... thus removing
         | yourself from the equation and hopefully satiating anyone
         | watching.
         | 
         | The time scales and distances involved meant that you weren't
         | really perceived as a threat until you approached the ability
         | to reach light speed, which made you stick out enough to be
         | noticed in far corners of the universe. We broadcast radio, but
         | it's not loud or far-reaching enough to be noticed by the far-
         | out civilization destroying overlords. It _was_ loud enough for
         | a different nearby civilization to come destroy us in an
         | attempt to save themselves from being destroyed along with us.
         | 
         | Of course, when applied in reality who the hell knows.
        
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