10 ms·

A Simple Model of Grabby Aliens

86 points by ndr 6y ago

tlb 6y ago
It's interesting that, under the given assumptions, you can put such tight bounds on the frequency of origination of grabby aliens. The assumption that seems most unlikely is that civilizations will simply stop expanding when they encounter another one. Even if most civilizations would stop, a single aggressive one would quickly dominate. Especially under the assumption that they can expand at a large fraction of the speed of light, a defender would have little ability to organize a defense before being overrun.
- philip142au 6y ago
  There's going to be a lot of space wars
  - DaiPlusPlus 6y ago
    Indeed, a very inefficient use of limited resources and energy in the known universe. How irrational.
    - nvet4 6y ago
      Calling war irrational is irrational.
      - Geezus_42 6y ago
        War is irrational...
        pc86 6y ago
        If you have limited resourced (no money), but you do have military power, you can invade a neighbor with resources. If a neighbor invades you, you defend yourself. Neither of those positions is irrational, except maybe the first (maybe), but there's certainly scenarios where it would be your only choice.
        throwaway316943 6y ago
        It becomes irrational when you develop the capacity for mutually assured destruction.
        omginternets 6y ago
        MAD is grounded in game theory. It is designed to make the only winning move “don’t play”. It’s hyper-rational.
        DaiPlusPlus 6y ago
        MAD happened because of a (real, or perceived, I’m unsure myself...) risk of the Soviet Union invading Western Europe - and NATO ended up calculating that maintaining a nuclear deterrence was more affordable and more feasible than resisting a Warsaw Pact invasion using conventional forces. This assumes any kind of Soviet expansionism must be an absolute evil because the position is logically equivalent to “death is a preferable alternative to communism” (to steal a phrase from a video game...) which is patently absurd: it’s rational to prefer reduced standards of living over death, but credible deterrence requires drawing and maintaining a hard-line, even if that line is arbitrarily placed. ...given all of that is due to the risk of aggression from the Soviets, and I believe NATO may have disarmed themselves unilaterally if they didn’t see the SU/WP as a military threat (regardless of ideological threats) - what was making the SU so concerned about NATO military threats? Did the SU still have expansionist designs... or did they actually believe NATO still wanted to liberate/claim Poland long after the 1960s?
        omginternets 6y ago
        I respectfully insist: you are mistaken. MAD is a formal (i.e. mathematical) model. It is 100%, unequivocally rational. The problem is that this rational process leads to outcomes you and I dislike. These "bad outcomes" are value judgements. That is, MAD's outocmes don't align with our values. Therefore, the problem with mad (on which we agree!) is based in something extra-rational: values. Again: you and I agree there is a problem with MAD. Where you are wrong is that the problem is not "MAD is irrational". The problem is "MAD's logical conclusions run afoul of our values".
        dukeofdoom 6y ago
        I read somewhere there's been something like 3000 wars in recorded human history. Seems like a pretty frequent thing. Thru out human history, raiding weaker neighbouring villages for resources, or access to females would be pretty rational behaviour for your villages growth and continuing success of your close genetic relatives. So much so that parts of Human Male's anatomy seems to be purposely driven for combat and survival. Things like larger muscles, thickness of skull, thickness of neck. Also, societies seem to come together and cooperate, hunker down, in war and conflict. Also seems to me to have some genetic component to that social behaviour. Only about 50% of men have reproduced through out human history. Raiding a neighbouring village, killing the man, and taking the best women for wives would be a rational though unethical behaviour. Its exactly what the Vikings did. In fact, there's a growing concern that large and growing percentage of men, currently unattractive to females (internet incels) will lead to radicalization and possibly conflict in the west. As those man try to better their odds of reproduction. Currently they are genetic rejects.
- smoyer 6y ago
  Your assumption sounds like it favors Star Wars over Star Trek (TOS).
- ta202102 6y ago
  The wording 'stop expanding' is confusing. Figure 1 makes it more clear: When two civilizations meet, expansion stops in this direction. In the free directions the civilizations still expand.
- protoman3000 6y ago
  I disagree. Countries and states exist.
- throwaway316943 6y ago
  What does a war between two interstellar civilizations look like? If they can accelerate mass to a high fraction of the speed of light doesn’t that mean their first strike weapons are all planet killers? If we assume they still primarily use planets as the sites of their industrial and population centres then doesn’t that mean any systems within striking distance are immediately obliterated by large, dark, unstoppable projectiles travelling at 0.7c? Any point defence you can think of fails when you can easily throw millions of these at a planet. There’s no way to win that game for either side. If we change our assumptions about whether they live on or even care about planets it becomes a very different story. Who knows if they even need the free energy that stars emit. Most of the interstellar medium is ionized so it may be that it’s much easier to just scoop up gas and dust with magnetic fields than it is to attempt to extract large quantities of matter from planets that are few and far between not to mention gravitationally bound.
  - smichel17 6y ago
    Perhaps the winning move, like with today's nuclear weaponry, simply not to play.
    - goatlover 6y ago
      Or to hide in the Dark Forest instead of announcing yourself to the cosmos.
      - generalizations 6y ago
        This does seem to be the logical conclusion of a game theory analysis. Since planet killers can show up without any warning, the only solution is make it impossible to aim your unstoppable weapons, which means you have to be impossible to detect or locate. So as you said, maybe the solution to the Fermi Paradox is that every surviving civilization is hiding in cloaked habitats within the vastness of intergalactic space.
        jerf 6y ago
- zamfi 6y ago
  > Even if most civilizations would stop, a single aggressive one would quickly dominate. Would this affect their model, though? If either of the two civilizations dominates, rather than both being obliterated through mutual destruction, you would expect to see the same thing: that volume of space time is now occupied by a civilization. I’m not sure it matters which one (to their model, of course it would presumably matter to the inhabitants) — and either would be visible and have the effect described in the paper.
  - codeflo 6y ago
    That was my read as well, it doesn’t make a difference in terms of the total volume occupied by these “grabby” civs. Also, one civilization dominating wouldn’t mean that the other one would magically disappear. As a simple assumption, I can imagine the stronger civ expanding into the territory of the weaker one relatively unhindered (in terms of expansion speed). But the weaker civ would still expand outwards as well. If it’s expansion speed isn’t slower, it would continue to grow in absolute size.
  - MattRix 6y ago
    Yep, this was my understanding too. It doesn’t change the fact that the area in space and time is now occupied by grabby aliens. The model and diagrams could easily be modified to use some heuristic like allowing older civilizations to take over younger ones when they collide, but it wouldn’t really matter for the purposes of the argument.
- PaulHoule 6y ago
  How could they stop? If a civilization is spread out in a 10000 light year area and encounters another in one place it seems impossible they could make a collective decision given the amount of communication that it would take.
  - bryanrasmussen 6y ago
    If that's the case they wouldn't be able to collectively decide to keep expanding either, the decision would have to be made by the parts of the civilization that came in contact with the other civilization. This implies a lot of things though - let us say we expand to Mars and manage to terraform it somehow - after a few hundred years though Mars has enough of a population that they end up needing new resources (obviously we need some story as to how they expand this quickly, I blame genetic engineering and Hoxar Matos the dictator-general of Mars who commands a billion test tube babies be born and raised by robots in the underground Martian nursery creches). The model for grabby aliens is that Mars must find somewhere else to expand as they are part of the human civilization - but given human civilization it seems more like splitting the civilization and infighting to get more resources would be the most likely outcome.
- sandworm101 6y ago
  As likely is that two grabby expanding civilizations make be so different that thier volumes intercept without conflict. If one only likes warm rocky planets, and the other doesnt bother with solar systems, they might not even see each other as they pass. The "grabbed" volumes would then overlap, mooting this model. Contact would then not be a function or time and speed rather a matter of curiosity and willingness to explore non-desireable parts of one's grabbed space.
  - barry-cotter 6y ago
    > As likely is that two grabby expanding civilizations make be so different that thier volumes intercept without conflict. Every volume contains only a certain amount of potential free energy that can be used before the end. That’s what you fight over. Dyson Spheres, fusion, antimatter, these are all details. Everybody wants negentropy and it’s a zero sum game.
- throwanem 6y ago
  > It's interesting that, under the given assumptions, you can put such tight bounds on... Is it, though? Grant me whatever assumptions I like and I can put tight bounds on anything - as long as it's unfalsifiable, at least.
deleted 6y ago
[deleted]
doof_warrior 6y ago
Cant help but think this is GPT-3 generated.
- AppleTrees2 6y ago
  I started reading, it seems to pass the smell test for now, will continue reading
- ModernMech 6y ago
  The word “till” in the abstract is certainly out of place. I’ve never seen slang like this in a scientific paper.
  - goodcanadian 6y ago
    The word "till" is not slang. From https://www.dictionary.com/browse/till https://www.dictionary.com/browse/till Till and until are both old in the language and are interchangeable . . . Also First recorded before 900; Middle English; Old English (north) til “to,” from Old Norse til “to,” . . .
    - ModernMech 6y ago
      Well its usage has been beaten out of me for scientific papers, and I’ve never seen it used in the venues I read. Maybe I just need to read more papers.
    - Igelau 6y ago
      TIL
  - ripe 6y ago
    Till is a perfectly valid, formal word. I was just having this argument yesterday: Many people assume that till is a misshapen abbreviation of until... However, till is not a shortening of until. It actually predates the longer word. The above paragraph is from Merriam-Webster: https://www.merriam-webster.com/words-at-play/should-you-use-until-or-till-or-til https://www.merriam-webster.com/words-at-play/should-you-use...
ur-whale 6y ago
I was under the impression that Aliens were partial to probing rather than grabbing. I must have been misinformed. I blame the media!
HONEST_ANNIE 6y ago
Hanson’s model is an ecological model. It assumes that modeled entities don’t reflect the model and respond to it. With intelligent agents simple ecological modelling may not work. You need to use game theory and strategic thinking. Assuming intelligent aliens, they know this model. Assuming stable state alien civilizations, they have countermeasures. Grabby Aliens might discover immune system against cancer-like civilizations growing without limit. It should hit them early before they are metastasized. Grabby Aliens might foresee immune system even before they encounter resistance. They might try stealthy expansion, gradual probing first strategy, or modify their behavior in order to survive, .... and so on.
- sfifs 6y ago
  > It should hit them early before they are metastasized. They might try stealthy expansion, gradual probing first strategy, or modify their behavior in order to survive This essentially is the Dark Forest hypothesis explanation for the Fermi Paradox. Civilizations work to avoid drawing attention to themselves because might be exterminated as potentially cancerous if detected
JoeAltmaier 6y ago
There are a lot of stars. Maybe enough to go around. Anyway, its commonly been theorized that waging war across unimaginable interstellar distances is unlikely or even impossible. Hard enough to seed another system with a spore, much less export capability to wage war.
- PaulHoule 6y ago
  If could accelerate a projectile to 0.1c you wouldnt bother putting any kind of warhead on it. Interstellar bombardment of a single planet seems possible but if you had asteroid mining in one solar system or a multi solar system I think the targeting problem is intractable.
  - JoeAltmaier 6y ago
    Kind of the opposite of 'expansion'. That's essentially 'demolition'. Not going to be anything worth expanding into, after that. Like blowing up a safe generally incinerates the money inside.
PaulHoule 6y ago
I wonder if the inner solar system is a ghetto. If the base requirement for life is liquid water, then it is a generic property that you find it in most moons and dwarf planets, usually driven by pressure and geothermal or tidal energy. If the under layer is rock instead of ice you could have thermal vent economies like we have in ocean rifts. In comparison the Earth is a really dry place, the most special thing about it is that the plants support an oxygen economy that might not be necessary for complex life but it sure helps. Any species that masters interstellar travel is going to know how to cut up something like Ceres or Pluto into hundreds of thousands of miles of shopping malls and apartment buildings and might not find inner solar system bodies that interesting. In fact they might not even have an off-the-shelf landing vehicle that would work on Earth and might spend a few years developing one.
- simonh 6y ago
  It’s very difficult to tell what environment ‘typical’ aliens evolve in. It seems like Earth is probably a very unusual planet, mainly due to our very large moon which has stripped away so much of our atmosphere. Most planets our size will have atmospheres much more like that of Venus in terms of density at least. Smaller planets might develop atmospheres like ours in terms of density, as Mars did, but won’t be able to retain them for long. Even a modest increase in Earths gravity, or significantly denser atmosphere would make reaching orbit unviable. I also don’t see how life evolving in liquid voids on outer planet moons, or similar environments, could develop much beyond simple invertebrates or equivalent. I’m really despairing that spacefaring civilisations are at all likely. Life yes, I think it’s likely to be reasonably common at the galactic level. Intelligent life, sure. But I think we’re fantastically lucky to be in the situation we find ourselves. I know statistics says we’re supposed to most likely be typical, but random chance doesn’t care about how many possibilities didn’t show up. If a lottery has a winner, that ticket won just as much no matter if there were 10 losers or a billion of them.
  - ianai 6y ago
    Agreed. When I learned that bit about the rocket equation and gravity - that just a little more gravity would make all known rocket tech unable leave Earth's atmosphere/gravity - my thoughts of life zipping around the universe dimmed greatly. Maybe we should look at it as our duty to devise ways to 'rescue' other biomes from their gravitational jails? (if only we weren't space orcs.)
h2odragon 6y ago
I'm neither expert nor elite enough to comment further: https://www.overcomingbias.com/2021/02/experts-versus-elites.html https://www.overcomingbias.com/2021/02/experts-versus-elites...
herendin 6y ago
From a human perspective, it's difficult to imagine a civilization that could remain cohesive when its territory is thousands of light-years wide, and therefore separated by time as well as space. Every significant journey is a trip into the future
- thepangolino 6y ago
  I’m not so sure about that. What comes to mind is all the successful trading companies of centuries past.
  - herendin 6y ago
    If you mean 17th century trading companies, their sailing ships had one way journey times of six months to one year to practically anywhere in the world. So it's an interesting example, but interstellar distances are usually many times longer: 5 (light) years or 10 years or much more. I guess that the reason globe-spanning empires and trading companies appeared from about 1600 on was in fact because sailing ships had reduced the travel time enough to allow a cohesive network with some centralized control. Previously, with slower communications, they tended to lose control of the extremities and devolve to looser associations (because the lag was excessive, on the scale of a human life)
idlewords 6y ago
This is just the same set of anxieties and hopes, ultimately religious in nature, that surround "superintelligence", except this time projected into space.
- OscarCunningham 6y ago
  What would you say are the nonreligious answers to the same question?
  - idlewords 6y ago
    I think the answer requires more epistemic humility. You can't anticipate the behavior of a hyperintelligent entity (almost by definition) even if you build it right in your own lab. And about the only thing we know about aliens is that they'll be alien. So right there you have two dimensions of "unknown unknowns" that this analysis sweeps aside. The pattern that I find distasteful in this kind of thinking is deducing universal rules of complex behavior from a few first principles. A good analogue of this is the Cold War era infatuation with game theory, as it would pertain to nuclear war, or many simple models of economics. We know that in reality, human beings are quite complex, and their actual behavior bears no relationship to such "first principles" models, no matter how persuasive their authors find them. Yet we have the advantage of being human and understanding our own thinking. The idea that we could be more successful making such inferences from first principles about non-human, hyperintelligent entities, when we can't do it for ourselves, is laughable. Even such basic questions like "does life always arise from Darwinian evolution" or "what is the physical basis of consciousness" are open. So in a strong sense we know nothing at all about the nature of intelligent life in the Universe, except that it happened at least once, and caused everyone no end of trouble.
- zackmorris 6y ago
  Ya I was just thinking that the fact we haven't discovered aliens is strong evidence of new physics. Otherwise we'd see their electromagnetic emissions everywhere. I tend to think that we're just 1 or 2 discoveries away from a very different view of the universe. The low hanging fruit being stuff like: detecting neutrinos cheaply, having a better understanding of quantum computing/entanglement/etc, knowing how the extra dimensions at subatomic levels work (and how a dimension might be lost/gained or open up sub-universes within black holes), understanding how the electromagnetic/strong/weak/gravity forces converge at high energies and how to modulate one or more with the others, etc. If we're able to take all that stuff for granted, then the answer is probably that aliens communicate over some kind of encrypted quantum communication channel over something like neutrinos that is very hard to detect. They probably live around energy sources like magnetars and black holes and such so there's no way we'll ever see them against that glare. And their brains have almost certainly been uploaded to a metaverse that we have difficulty imagining, where our whole planet's computation would fit on a microscopic chip of theirs. I guess what I'm saying is, we might be more likely to find aliens through an altered state than out in space. They're probably here right now waiting for a knock on the door, once we know which door we're looking for. So yes, their superintelligent technology that's indistinguishable from magic to us might as well be religion at this point.

86 points by ndr 6y ago

tlb 6y ago

It's interesting that, under the given assumptions, you can put such tight bounds on the frequency of origination of grabby aliens. The assumption that seems most unlikely is that civilizations will simply stop expanding when they encounter another one. Even if most civilizations would stop, a single aggressive one would quickly dominate. Especially under the assumption that they can expand at a large fraction of the speed of light, a defender would have little ability to organize a defense before being overrun.

philip142au 6y ago
There's going to be a lot of space wars
- DaiPlusPlus 6y ago
  Indeed, a very inefficient use of limited resources and energy in the known universe. How irrational.
  - nvet4 6y ago
    Calling war irrational is irrational.
    - Geezus_42 6y ago
      War is irrational...
      - pc86 6y ago
        If you have limited resourced (no money), but you do have military power, you can invade a neighbor with resources. If a neighbor invades you, you defend yourself. Neither of those positions is irrational, except maybe the first (maybe), but there's certainly scenarios where it would be your only choice.
        throwaway316943 6y ago
        It becomes irrational when you develop the capacity for mutually assured destruction.
        omginternets 6y ago
        MAD is grounded in game theory. It is designed to make the only winning move “don’t play”. It’s hyper-rational.
        DaiPlusPlus 6y ago
        MAD happened because of a (real, or perceived, I’m unsure myself...) risk of the Soviet Union invading Western Europe - and NATO ended up calculating that maintaining a nuclear deterrence was more affordable and more feasible than resisting a Warsaw Pact invasion using conventional forces. This assumes any kind of Soviet expansionism must be an absolute evil because the position is logically equivalent to “death is a preferable alternative to communism” (to steal a phrase from a video game...) which is patently absurd: it’s rational to prefer reduced standards of living over death, but credible deterrence requires drawing and maintaining a hard-line, even if that line is arbitrarily placed. ...given all of that is due to the risk of aggression from the Soviets, and I believe NATO may have disarmed themselves unilaterally if they didn’t see the SU/WP as a military threat (regardless of ideological threats) - what was making the SU so concerned about NATO military threats? Did the SU still have expansionist designs... or did they actually believe NATO still wanted to liberate/claim Poland long after the 1960s?
        omginternets 6y ago
        I respectfully insist: you are mistaken. MAD is a formal (i.e. mathematical) model. It is 100%, unequivocally rational. The problem is that this rational process leads to outcomes you and I dislike. These "bad outcomes" are value judgements. That is, MAD's outocmes don't align with our values. Therefore, the problem with mad (on which we agree!) is based in something extra-rational: values. Again: you and I agree there is a problem with MAD. Where you are wrong is that the problem is not "MAD is irrational". The problem is "MAD's logical conclusions run afoul of our values".
      - dukeofdoom 6y ago
        I read somewhere there's been something like 3000 wars in recorded human history. Seems like a pretty frequent thing. Thru out human history, raiding weaker neighbouring villages for resources, or access to females would be pretty rational behaviour for your villages growth and continuing success of your close genetic relatives. So much so that parts of Human Male's anatomy seems to be purposely driven for combat and survival. Things like larger muscles, thickness of skull, thickness of neck. Also, societies seem to come together and cooperate, hunker down, in war and conflict. Also seems to me to have some genetic component to that social behaviour. Only about 50% of men have reproduced through out human history. Raiding a neighbouring village, killing the man, and taking the best women for wives would be a rational though unethical behaviour. Its exactly what the Vikings did. In fact, there's a growing concern that large and growing percentage of men, currently unattractive to females (internet incels) will lead to radicalization and possibly conflict in the west. As those man try to better their odds of reproduction. Currently they are genetic rejects.
smoyer 6y ago
Your assumption sounds like it favors Star Wars over Star Trek (TOS).
ta202102 6y ago
The wording 'stop expanding' is confusing. Figure 1 makes it more clear: When two civilizations meet, expansion stops in this direction. In the free directions the civilizations still expand.
protoman3000 6y ago
I disagree. Countries and states exist.
throwaway316943 6y ago
What does a war between two interstellar civilizations look like? If they can accelerate mass to a high fraction of the speed of light doesn’t that mean their first strike weapons are all planet killers? If we assume they still primarily use planets as the sites of their industrial and population centres then doesn’t that mean any systems within striking distance are immediately obliterated by large, dark, unstoppable projectiles travelling at 0.7c? Any point defence you can think of fails when you can easily throw millions of these at a planet. There’s no way to win that game for either side. If we change our assumptions about whether they live on or even care about planets it becomes a very different story. Who knows if they even need the free energy that stars emit. Most of the interstellar medium is ionized so it may be that it’s much easier to just scoop up gas and dust with magnetic fields than it is to attempt to extract large quantities of matter from planets that are few and far between not to mention gravitationally bound.
- smichel17 6y ago
  Perhaps the winning move, like with today's nuclear weaponry, simply not to play.
  - goatlover 6y ago
    Or to hide in the Dark Forest instead of announcing yourself to the cosmos.
    - generalizations 6y ago
      This does seem to be the logical conclusion of a game theory analysis. Since planet killers can show up without any warning, the only solution is make it impossible to aim your unstoppable weapons, which means you have to be impossible to detect or locate. So as you said, maybe the solution to the Fermi Paradox is that every surviving civilization is hiding in cloaked habitats within the vastness of intergalactic space.
      - jerf 6y ago
zamfi 6y ago
> Even if most civilizations would stop, a single aggressive one would quickly dominate. Would this affect their model, though? If either of the two civilizations dominates, rather than both being obliterated through mutual destruction, you would expect to see the same thing: that volume of space time is now occupied by a civilization. I’m not sure it matters which one (to their model, of course it would presumably matter to the inhabitants) — and either would be visible and have the effect described in the paper.
- codeflo 6y ago
  That was my read as well, it doesn’t make a difference in terms of the total volume occupied by these “grabby” civs. Also, one civilization dominating wouldn’t mean that the other one would magically disappear. As a simple assumption, I can imagine the stronger civ expanding into the territory of the weaker one relatively unhindered (in terms of expansion speed). But the weaker civ would still expand outwards as well. If it’s expansion speed isn’t slower, it would continue to grow in absolute size.
- MattRix 6y ago
  Yep, this was my understanding too. It doesn’t change the fact that the area in space and time is now occupied by grabby aliens. The model and diagrams could easily be modified to use some heuristic like allowing older civilizations to take over younger ones when they collide, but it wouldn’t really matter for the purposes of the argument.
PaulHoule 6y ago
How could they stop? If a civilization is spread out in a 10000 light year area and encounters another in one place it seems impossible they could make a collective decision given the amount of communication that it would take.
- bryanrasmussen 6y ago
  If that's the case they wouldn't be able to collectively decide to keep expanding either, the decision would have to be made by the parts of the civilization that came in contact with the other civilization. This implies a lot of things though - let us say we expand to Mars and manage to terraform it somehow - after a few hundred years though Mars has enough of a population that they end up needing new resources (obviously we need some story as to how they expand this quickly, I blame genetic engineering and Hoxar Matos the dictator-general of Mars who commands a billion test tube babies be born and raised by robots in the underground Martian nursery creches). The model for grabby aliens is that Mars must find somewhere else to expand as they are part of the human civilization - but given human civilization it seems more like splitting the civilization and infighting to get more resources would be the most likely outcome.
sandworm101 6y ago
As likely is that two grabby expanding civilizations make be so different that thier volumes intercept without conflict. If one only likes warm rocky planets, and the other doesnt bother with solar systems, they might not even see each other as they pass. The "grabbed" volumes would then overlap, mooting this model. Contact would then not be a function or time and speed rather a matter of curiosity and willingness to explore non-desireable parts of one's grabbed space.
- barry-cotter 6y ago
  > As likely is that two grabby expanding civilizations make be so different that thier volumes intercept without conflict. Every volume contains only a certain amount of potential free energy that can be used before the end. That’s what you fight over. Dyson Spheres, fusion, antimatter, these are all details. Everybody wants negentropy and it’s a zero sum game.
throwanem 6y ago
> It's interesting that, under the given assumptions, you can put such tight bounds on... Is it, though? Grant me whatever assumptions I like and I can put tight bounds on anything - as long as it's unfalsifiable, at least.

deleted 6y ago

[deleted]

doof_warrior 6y ago

Cant help but think this is GPT-3 generated.

AppleTrees2 6y ago
I started reading, it seems to pass the smell test for now, will continue reading
ModernMech 6y ago
The word “till” in the abstract is certainly out of place. I’ve never seen slang like this in a scientific paper.
- goodcanadian 6y ago
  The word "till" is not slang. From https://www.dictionary.com/browse/till https://www.dictionary.com/browse/till Till and until are both old in the language and are interchangeable . . . Also First recorded before 900; Middle English; Old English (north) til “to,” from Old Norse til “to,” . . .
  - ModernMech 6y ago
    Well its usage has been beaten out of me for scientific papers, and I’ve never seen it used in the venues I read. Maybe I just need to read more papers.
  - Igelau 6y ago
    TIL
- ripe 6y ago
  Till is a perfectly valid, formal word. I was just having this argument yesterday: Many people assume that till is a misshapen abbreviation of until... However, till is not a shortening of until. It actually predates the longer word. The above paragraph is from Merriam-Webster: https://www.merriam-webster.com/words-at-play/should-you-use-until-or-till-or-til https://www.merriam-webster.com/words-at-play/should-you-use...

ur-whale 6y ago

I was under the impression that Aliens were partial to probing rather than grabbing. I must have been misinformed. I blame the media!

HONEST_ANNIE 6y ago

Hanson’s model is an ecological model. It assumes that modeled entities don’t reflect the model and respond to it. With intelligent agents simple ecological modelling may not work. You need to use game theory and strategic thinking. Assuming intelligent aliens, they know this model. Assuming stable state alien civilizations, they have countermeasures. Grabby Aliens might discover immune system against cancer-like civilizations growing without limit. It should hit them early before they are metastasized. Grabby Aliens might foresee immune system even before they encounter resistance. They might try stealthy expansion, gradual probing first strategy, or modify their behavior in order to survive, .... and so on.

sfifs 6y ago
> It should hit them early before they are metastasized. They might try stealthy expansion, gradual probing first strategy, or modify their behavior in order to survive This essentially is the Dark Forest hypothesis explanation for the Fermi Paradox. Civilizations work to avoid drawing attention to themselves because might be exterminated as potentially cancerous if detected

JoeAltmaier 6y ago

There are a lot of stars. Maybe enough to go around. Anyway, its commonly been theorized that waging war across unimaginable interstellar distances is unlikely or even impossible. Hard enough to seed another system with a spore, much less export capability to wage war.

PaulHoule 6y ago
If could accelerate a projectile to 0.1c you wouldnt bother putting any kind of warhead on it. Interstellar bombardment of a single planet seems possible but if you had asteroid mining in one solar system or a multi solar system I think the targeting problem is intractable.
- JoeAltmaier 6y ago
  Kind of the opposite of 'expansion'. That's essentially 'demolition'. Not going to be anything worth expanding into, after that. Like blowing up a safe generally incinerates the money inside.

PaulHoule 6y ago

I wonder if the inner solar system is a ghetto. If the base requirement for life is liquid water, then it is a generic property that you find it in most moons and dwarf planets, usually driven by pressure and geothermal or tidal energy. If the under layer is rock instead of ice you could have thermal vent economies like we have in ocean rifts. In comparison the Earth is a really dry place, the most special thing about it is that the plants support an oxygen economy that might not be necessary for complex life but it sure helps. Any species that masters interstellar travel is going to know how to cut up something like Ceres or Pluto into hundreds of thousands of miles of shopping malls and apartment buildings and might not find inner solar system bodies that interesting. In fact they might not even have an off-the-shelf landing vehicle that would work on Earth and might spend a few years developing one.

simonh 6y ago
It’s very difficult to tell what environment ‘typical’ aliens evolve in. It seems like Earth is probably a very unusual planet, mainly due to our very large moon which has stripped away so much of our atmosphere. Most planets our size will have atmospheres much more like that of Venus in terms of density at least. Smaller planets might develop atmospheres like ours in terms of density, as Mars did, but won’t be able to retain them for long. Even a modest increase in Earths gravity, or significantly denser atmosphere would make reaching orbit unviable. I also don’t see how life evolving in liquid voids on outer planet moons, or similar environments, could develop much beyond simple invertebrates or equivalent. I’m really despairing that spacefaring civilisations are at all likely. Life yes, I think it’s likely to be reasonably common at the galactic level. Intelligent life, sure. But I think we’re fantastically lucky to be in the situation we find ourselves. I know statistics says we’re supposed to most likely be typical, but random chance doesn’t care about how many possibilities didn’t show up. If a lottery has a winner, that ticket won just as much no matter if there were 10 losers or a billion of them.
- ianai 6y ago
  Agreed. When I learned that bit about the rocket equation and gravity - that just a little more gravity would make all known rocket tech unable leave Earth's atmosphere/gravity - my thoughts of life zipping around the universe dimmed greatly. Maybe we should look at it as our duty to devise ways to 'rescue' other biomes from their gravitational jails? (if only we weren't space orcs.)

h2odragon 6y ago

I'm neither expert nor elite enough to comment further: https://www.overcomingbias.com/2021/02/experts-versus-elites.html https://www.overcomingbias.com/2021/02/experts-versus-elites...

herendin 6y ago

From a human perspective, it's difficult to imagine a civilization that could remain cohesive when its territory is thousands of light-years wide, and therefore separated by time as well as space. Every significant journey is a trip into the future

thepangolino 6y ago
I’m not so sure about that. What comes to mind is all the successful trading companies of centuries past.
- herendin 6y ago
  If you mean 17th century trading companies, their sailing ships had one way journey times of six months to one year to practically anywhere in the world. So it's an interesting example, but interstellar distances are usually many times longer: 5 (light) years or 10 years or much more. I guess that the reason globe-spanning empires and trading companies appeared from about 1600 on was in fact because sailing ships had reduced the travel time enough to allow a cohesive network with some centralized control. Previously, with slower communications, they tended to lose control of the extremities and devolve to looser associations (because the lag was excessive, on the scale of a human life)

idlewords 6y ago

This is just the same set of anxieties and hopes, ultimately religious in nature, that surround "superintelligence", except this time projected into space.

OscarCunningham 6y ago
What would you say are the nonreligious answers to the same question?
- idlewords 6y ago
  I think the answer requires more epistemic humility. You can't anticipate the behavior of a hyperintelligent entity (almost by definition) even if you build it right in your own lab. And about the only thing we know about aliens is that they'll be alien. So right there you have two dimensions of "unknown unknowns" that this analysis sweeps aside. The pattern that I find distasteful in this kind of thinking is deducing universal rules of complex behavior from a few first principles. A good analogue of this is the Cold War era infatuation with game theory, as it would pertain to nuclear war, or many simple models of economics. We know that in reality, human beings are quite complex, and their actual behavior bears no relationship to such "first principles" models, no matter how persuasive their authors find them. Yet we have the advantage of being human and understanding our own thinking. The idea that we could be more successful making such inferences from first principles about non-human, hyperintelligent entities, when we can't do it for ourselves, is laughable. Even such basic questions like "does life always arise from Darwinian evolution" or "what is the physical basis of consciousness" are open. So in a strong sense we know nothing at all about the nature of intelligent life in the Universe, except that it happened at least once, and caused everyone no end of trouble.
zackmorris 6y ago
Ya I was just thinking that the fact we haven't discovered aliens is strong evidence of new physics. Otherwise we'd see their electromagnetic emissions everywhere. I tend to think that we're just 1 or 2 discoveries away from a very different view of the universe. The low hanging fruit being stuff like: detecting neutrinos cheaply, having a better understanding of quantum computing/entanglement/etc, knowing how the extra dimensions at subatomic levels work (and how a dimension might be lost/gained or open up sub-universes within black holes), understanding how the electromagnetic/strong/weak/gravity forces converge at high energies and how to modulate one or more with the others, etc. If we're able to take all that stuff for granted, then the answer is probably that aliens communicate over some kind of encrypted quantum communication channel over something like neutrinos that is very hard to detect. They probably live around energy sources like magnetars and black holes and such so there's no way we'll ever see them against that glare. And their brains have almost certainly been uploaded to a metaverse that we have difficulty imagining, where our whole planet's computation would fit on a microscopic chip of theirs. I guess what I'm saying is, we might be more likely to find aliens through an altered state than out in space. They're probably here right now waiting for a knock on the door, once we know which door we're looking for. So yes, their superintelligent technology that's indistinguishable from magic to us might as well be religion at this point.