29 ms·

A Visualization of Galactic Settlement

175 points by the-mitr 5y ago

fnord77 5y ago
so, in 13.51 billion years, where are they?
- ceejayoz 5y ago
  https://en.wikipedia.org/wiki/Fermi_paradox#Hypothetical_explanations_for_the_paradox https://en.wikipedia.org/wiki/Fermi_paradox#Hypothetical_exp...
- edgyquant 5y ago
  The joke answer is “who knows.” The real answer is likely living lives and in societies we don’t have the knowledge to fathom.
user-the-name 5y ago
> Ships are launched no more frequently (from both the home system and all settlements) than every 0.1 Myr — every 100,000 years; > Technology persists in a given settlement for 100 million years before dying out; Those are... uh, some kind of numbers. Really not sure what they think they are simulating here, but it sure does not sound like anything we'd expect to happen in reality.
- asdfasgasdgasdg 5y ago
  Maybe their birth rates are so close to the replacement rate they don't feel an urgent need to spread out from a given star system very quickly. Or maybe they have modified their sensibilities to prefer fully exploiting an existing system before moving on to a new one. But yeah these parameters do not seem realistic.
  - user-the-name 5y ago
    100 million years ago, grass didn't exist, let alone technology.
- Aeolun 5y ago
  Maybe they wanted to be conservative, because if they use the actual numbers the galaxy would go red in just a few frames?
  - jaspax 5y ago
    More like they have a bizarre mix of numbers which are way too large and those which are way too small. Technological civilization lasting 100M years per planet? But those civilizations only try to colonize once per 100K years? And, at the same time, their colony ships take tens of thousands of years to reach their destinations? I have a hard time imagining ways in which all of those are true at once.
    - foerbert 5y ago
      I'm not sure why you see this as so bizarre. This seems like a fairly conservative estimate across the board, intended to be used to produce some kind of lower bound, rather than be an expected case. This is a pretty common and normal idea. Is it that you think the technological civilization duration is not conservative? Remember we're talking about a civilization that can cross the galaxy here. They can show up in a star system and throw habitats across any planets, moons, or asteroids they find appealing. They can also set up whatever number of space structures they want. What exactly do you think is so likely to utterly extinguish this species in every star system within 100M years? The long duration between colonization events is not only highly conservative, it also functions here to allow any particular civilization to be pretty irrelevant. Even if some crazy war breaks out within a star system, a single surviving habitat is enough to allow the next colonization to still occur. So, yeah? It all strikes me as a pretty normal conservative estimate intended to let them figure out some kind of reasonable lower bound here. All pretty normal stuff.
      - user-the-name 5y ago
        What is "conservative" about a civilisation lasting 100 million years? That is literally astronomical. That about twice as long as grass has existed.
throwaway316943 5y ago
I’m not a fan of galactic settlement simulations mostly because I think they simulate the wrong thing which is rate of diffusion. This treats the civilization as a static thing that simply spreads out at the edges. Compared to the history of human civilizations this is clearly unrealistic. The question to answer is what happens within the already colonized systems over time. How often would breakaway civilizations appear, wars, extinction events, mind upload cults, Luddite revolutions, stagnation, etc. Filters abound. The great civilizations of Earth’s past have succumbed to similar fates and we’ve only progressed by starting over again and again.
- JackFr 5y ago
  It’s true that filters abound but the idea that we’ve had to start all over again is Whig history. It’s been a continuum. That being said I agree with your main point. The difference in worldview, ethics, where man sees himself in the universe over the course of our history (let alone pre-history) has taken dramatic and difficult to model changes. Imagine the worldview of the builders of the Great Pyramid vis a vis our own. (And then remember that Cleopatra was far closer in time to us than them.)
  - QuesnayJr 5y ago
    Isn't it the opposite of Whig history? I thought Whig history was the idea of continual progress.
    - throwaway316943 5y ago
      Yes, thank you, that’s essentially what I’m arguing against. There’s no reason galactic civilizations should continually progress especially when each settled system is effectively cut off from its parent by light years of distance.
      - stubish 5y ago
        I think it will depend on how stable the culture is when it gets that far. Will our language become static, now we have the printing press and Netflix? We are still changing, where books and films from 80 years ago have not aged well due to social attitudes. But if it stabilizes, maybe the culture stabilizes, and maybe it can be stable enough for million year time frames. It might not even happen here.... maybe in a million years after the first colony or three has happened one of them will develop a culture capable of becoming galaxy spanning. I think it is worth noting that a new settlement will not be completely cut off from its parent. I imagine a new settlement around Alpha Centauri will be greedily consuming Earth media for quite some time, delayed by just a few years, until it progresses far enough for its own exotic drammedys to be consumed by Earth.
aj7 5y ago
It seems like it would be trivial for a civilization to have a policy of no electromagnetic emissions so no signature at all. 10km/second is absurdly slow. Who would want to make the trip, and condemn thousands of generations of her progeny to bizarre ship life and culture?
- signal11 5y ago
  > Who Civilizations aware of imminent extinction-level events may choose to do that, similar to how shipwrecked sailors may fashion a raft and "risk it" in the off-chance they survive.
  - edgyquant 5y ago
    But why would they go off to a different system instead of just colonizing around their sun or even other planets close to them? If it’s their star is gonna blow why would they go any further than the nearest star?
    - signal11 5y ago
      Depends on the ELE. There are several which can swallow entire solar systems, and the nearby stars may not be hospitable. Maybe the endgame is to find a habitable planet?
- Aeolun 5y ago
  > Who would want to make the trip, and condemn thousands of generations of her progeny Presumably the people that do this do not think ship life will be that bizarre. I’m frankly more concerned about the sustainability aspect than how daily life will work.
- spywaregorilla 5y ago
  Ship life would probably be better than the lives many people experience today, in first world countries. There's also probably some super advanced VR by that time.
- keiferski 5y ago
marcus_holmes 5y ago
Colour me a little disappointed. Firstly, this seems obvious. The conclusion of "even really slow spaceships will colonise the galaxy given enough time" is almost mind-numbingly banal. Secondly, the parameters seem to be chosen in order to produce an "interesting" propagation pattern, rather than based on any actual data or guesstimates (I know there is no data, but making shit up is no substitute). Thirdly, it doesn't answer the big important question of "where are they?" (as fnord77 asks). Saying "even really slow spaceships will colonise the galaxy given enough time" brings us immediately right back to "how much is enough time to colonise the entire galaxy?" which they then say is ~1 billion years. Fourthly, but they're not here. So the answer to that question must be "over ~10 billion years". So either the simulation is wrong (because it takes longer than ~1 billion years) or it's pointless (because the only other explanation is that there has been no such colonisation effort, so why are we modelling it?). This wasn't addressed at all. Fifthly, this assumes that all solar systems can be colonised, and will produce another colony ship 100,000 years later (for inadequately explained reasons). Given that we know a fair bit about the actual galaxy (though the simulation doesn't look anything like our actual galaxy), why didn't they run the simulation on our actual galaxy, and exclude the stars that we know can't be colonised (because red giant, etc)? Finally. Is this the state of cutting-edge research on SETI? This wishful-thinking make-believe "look what I made Mum!" stuff? If this was a bootcamp dev showing off their WebGL modelling demo, I'd be impressed. 'nuff said. Sorry to be harsh, but... really? this is it?
- deleted 5y ago
  [deleted]
- avaldes 5y ago
  > Finally. Is this the state of cutting-edge research on SETI? This wishful-thinking make-believe "look what I made Mum!" stuff? If this was a bootcamp dev showing off their WebGL modelling demo, I'd be impressed. 'nuff said. Sorry to be harsh, but... really? this is it? I mean, when all you have to work is literally nothing all you can do is speculate. It is disappointing but what can they do but throw everything at the wall and see if it sticks.
  - 5y ago
rho4 5y ago
> one of the comments on the article site: "I have yet to see a convincing argument why advanced civilizations would need to constantly expand like bacteria in a petri dish." E.g. to escape from violence, conflict and war.
- pfdietz 5y ago
  The assumption there is that advanced civilizations only do things that they "need" to do. That's not true of any civilization at any point in history. Would an advanced civilization find value in colonization? Very likely -- colonization (biological or machine) is likely the cheapest way to explore another stellar system in detail, with explorers manufactured or born in situ.
h2odragon 5y ago
"looking for technosignatures" .. Which'd be what? AM radio transmissions? Spread spectrum stuff? How would we have interpreted our own "technosignature" 100 years ago? Compare the efforts it takes to talk to Voyager vs SETI: unless the aliens are talking to us in the way we are looking for we're not likely to see them. I won't even get in to the blithe assumptions about the ease of interstellar travel; Charlie Stross has a lot to say there and all said better than I could.
- unnouinceput 5y ago
  You can safely assume that one of the fundamental forces of our Universe is the same, namely electromagnetism, which means that yeah! AM/FM radio would be among those signatures.
  - h2odragon 5y ago
    Let me try to express that better: When we were just figuring out FM radio ourselves, i don't think we'd have been capable of recognizing a modern spread spectrum WiFi transmission as a signal. It would have been an elevated noise level and puzzling, perhaps. So the next hundred years of human advance, I expect, will bring similarly transformative changes in the ways we communicate and the shape of our "technosignature". Our expectations for what other species might be doing don't seem to be informed by the things we know we've done.
    - scotty79 5y ago
      Or in next 100 years we might figure out how to use neutrinos for communication and find out that galaxy is actually quite busy place, it's just nobody uses electromagnetic waves for comms same way they don't use smoke signals.
    - angus-prune 5y ago
      Related to this. We are basing what we consider natural phenomena on our observations of the galaxy. If we were to flip the assumption from life being rare to life being pervasive, what assumed natural phenomena could in fact be evidence of life? There is precedent for this on Earth. We are just startign to discover how much The Amazon rainforest is actually a human creation and basically a massive multi-generational bioengineering project. This is not a serious position fo mine, btw, I know that we can track most astronomical phenomena back to fundamental laws of nature. But equally there are some massive astronomical myseteries (dark matter/energy, certain stars being more/less common than expected etc) and I can't quite dismiss the wonder that our baseline assumptions have been tainted by this assumption.
gmuslera 5y ago
It may be the Dunning-Kruger effect for civilizations. The ones that didn't reach the stage of interstellar travel think that is trivial to travel and settle in other star systems. But the more advanced ones may have different ideas, or think that it is a waste of time/resources compared with some more interesting alternatives.
tomiplaz 5y ago
There's a great video on this topic from the Cool Worlds Lab channel: https://www.youtube.com/watch?v=c7OeeGcMFMc https://www.youtube.com/watch?v=c7OeeGcMFMc Taking into account ship ranges and settlement lifetimes produces very different results (15:36 in the video).
unnouinceput 5y ago
Looking at the video, and assuming that indeed that's how a Type II->Type III civilization spreads around, I've counted 2 full rotations of the original star. One rotation in our galaxy takes 230 million years (https://en.wikipedia.org/wiki/Galactic_year https://en.wikipedia.org/wiki/Galactic_year) which means even if we start today to spread around would still take half a billion years to populate the galaxy. Now if only genetics would deal away with aging to be around when that happens :).
cletus 5y ago
A lot of thought has gone into this area. I think the parameters of this simulation are too conservative, which is perhaps the point. Several issues: 1. Speeds are likely to be much higher. We largely rely on chemical propulsion plus gravity slingshots. For a sufficiently advanced civilization you're likely to concentrate a star's power to provide significant outward propulsion (and braking!) without the mass concerns of carrying reaction mass; 2. Once you've built one of those starships, it will likely continue on its journey after stopping at a new system to colonize and resupply. It's not clear to me if the simulation assumes this. Given the time frame of 1B years it seems not; 3. Stars in the Milky Way rotate at different speeds. Like in a few hundred thousand years we'll have a new closest neighbour for awhile. This potentially increases spread as the colonized systems drift further away extending their reach over time; 4. The simulation just looked like a collection of stars rather than, say, a spiral arm galaxy. So a realistic timeline is closer to 10M years than 1B years. I'm firmly in the camp that believes the speed of light is a hard limit. FTL drives and variants (eg wormholes) just seem to be wishful thinking by people who don't understand function domains (eg negative mass). Assuming that, a galaxy-spanning civilization is unlikely to be a civilization in the sense we understand it given that it might take you >1M years to cross from one side to the other. That's not really a problem for detecting such civilizations as the source of detection isn't likely to be EM transmissions (as the SETI program began looking for). Instead, it's likely to be the IR signatures of Dyson swarms. Short version: in space, the only way to cool down ultimately is to radiate that heat away into space. That radiation is completely dependent on the temperature of the object radiating heat. For any normal range temperature that's firmly in the IR range. So, if a star has a Dysown Swarm, it'll shine incredibly brightly as an IR source with a very low amount of visible light. Can you spot one such star? Possibly not. But an entire galaxy? You're likely to be able to see that from 1M+ LY away, easily. Given the small amount of time this would take to eventuate, in cosmological terms at least, the reason we haven't been able to detect any highly-advanced civilizations within our light cone is quite simple: there aren't any.
- s1artibartfast 5y ago
  #3 was very much included in the simulation Also, I don't think it was meant to be a fastest or even nominal case simulation. It could clearly be run with different inputs
PaulHoule 5y ago
Their propulsion speeds are low (today’s technology but you’d need D-D fusion or antimatter to keep warm) but 100 Myear survival time is hard to believe. I also don't believe a species that masters slow interstellar travel would care about stars and planets. Most of the mass which could be exploited by life is floating between the stars in the form of comets and if you could "live off the land" out there you could create millions of miles of apartment buildings and shopping malls. Why trek into an inner solar system and build yourself a space shuttle that can land full of fuel and then take off when you are settled into a space lifestyle?
- shakezula 5y ago
  > I also don't believe a species that masters slow interstellar travel would care about stars and planets. > Why trek into an inner solar system Why venture off to unknown shores to build yourself a farm when you're settled into a comfy European lifestyle? Although we only have ourselves as a data point, I think that natural curiosity is a strong evolutionary trait that we developed, and it's not a huge stretch to assume that other lifeforms would develop the same curiosity.
  - throwaway316943 5y ago
    I imagine an interstellar civilization would have this to say about planets: “A nice place to visit, but you wouldn’t want to live there”
bamurphymac1 5y ago
Early bird gets the worm.
carapace 5y ago
Two things: 1) Check out "The Millennial Project": https://en.wikipedia.org/wiki/The_Millennial_Project:_Colonizing_the_Galaxy_in_Eight_Easy_Steps https://en.wikipedia.org/wiki/The_Millennial_Project:_Coloni... > The Millennial Project: Colonizing the Galaxy in Eight Easy Steps by Marshall T. Savage is a book (published in 1992 and reprinted in 1994 with an introduction by Arthur C. Clarke) in the field of exploratory engineering that gives a series of concrete stages the author believes will lead to interstellar colonization. Many specific scientific and engineering details are presented, as are numerous issues involved in space colonization. I find the cover image of a green galaxy is very inspiring! 2) Due to the nature of exponential growth, we will eventually feel a population crunch when reproduction overwhelms the rate of expansion. This is true even if we invent FTL ships. The crunch would be delayed (perhaps for millions or billions of years) but it is inevitable.
biggestlou 5y ago
I'm still looking for intelligent life on this planet!
katabasis 5y ago
The simulation includes this assumption: > Technology persists in a given settlement for 100 million years before dying out Seems wildly speculative to me. Our own civilization has only been around for a tiny fraction of that time and future prospects are already looking pretty uncertain. And if we lived in a galaxy where civilizations had this kind of longevity, one would think we'd see some evidence of potential signals out there. My own pessimistic take on the Fermi Paradox is that life and intelligence may not be very unique but there is no reason for them to be long-lived either. Most civilizations are probably just a "flash in the pan", existing too briefly and separated by too great a distance to ever come into contact with another one (or even learn of another's existence).
- throwaway316943 5y ago
  My optimistic take is that advanced civilizations capable of travelling the galaxy don’t spend their time hanging around planets and stars for the same reason we no longer hang around caves and fire started by lightning. They’ve mastered fusion and matter transmutation so they just build their own habitats and energy sources wherever they want.
  - martinflack 5y ago
    > They’ve mastered fusion and matter transmutation so they just build their own habitats and energy sources wherever they want. ...and maybe not even within the four dimensions with which we're most familiar.
lapp0 5y ago
centauri-dreams.org ... Hmm, more like pipe-dreams.org
aaroninsf 5y ago
ITT: many propositions and counter-propositions constrained by presumptions that next-level civilization and its modes of being and interacting with the universe are "necessarily" much like our own. One example: "upload" and "simulation" do not have any predetermined relationship to the material behavior of a species engaged in it. The mapping between agency in any presented reality and the species-consensual one is arbitrary and the distinction between simulation and reality might just as well be framed as a question of sensorium cum UX. Very very little can be extrapolated upward from our own limitations and constitution either as individuals or societies or species. An even deeper example: fundamentals like the relationship to time may be radically different. It may not just scale, it may be fractal; and the notion of what constitutes agency and the locus of selfhood and identity, and hence self-interest, may be distributed emergent and predicated on an interplay between ant-and-colony at multiple levels, each of which is fully "conscious" and intentional in the sense we understand those things, at different time scales. What does a third grader know of amortization? We are not even out of the womb as a species.
xwdv 5y ago
One thing missing from this to help get a sense of scale is a running count of the number of souls populating the galaxy. Would be great if they can also show “settled” population and population in transit to some destination for settlement.
tectonic 5y ago
"Technology persists in a given settlement for 100 million years before dying out" That seems wildly optimistic.

175 points by the-mitr 5y ago

fnord77 5y ago

so, in 13.51 billion years, where are they?

ceejayoz 5y ago
https://en.wikipedia.org/wiki/Fermi_paradox#Hypothetical_explanations_for_the_paradox https://en.wikipedia.org/wiki/Fermi_paradox#Hypothetical_exp...
edgyquant 5y ago
The joke answer is “who knows.” The real answer is likely living lives and in societies we don’t have the knowledge to fathom.

user-the-name 5y ago

> Ships are launched no more frequently (from both the home system and all settlements) than every 0.1 Myr — every 100,000 years; > Technology persists in a given settlement for 100 million years before dying out; Those are... uh, some kind of numbers. Really not sure what they think they are simulating here, but it sure does not sound like anything we'd expect to happen in reality.

asdfasgasdgasdg 5y ago
Maybe their birth rates are so close to the replacement rate they don't feel an urgent need to spread out from a given star system very quickly. Or maybe they have modified their sensibilities to prefer fully exploiting an existing system before moving on to a new one. But yeah these parameters do not seem realistic.
- user-the-name 5y ago
  100 million years ago, grass didn't exist, let alone technology.
Aeolun 5y ago
Maybe they wanted to be conservative, because if they use the actual numbers the galaxy would go red in just a few frames?
- jaspax 5y ago
  More like they have a bizarre mix of numbers which are way too large and those which are way too small. Technological civilization lasting 100M years per planet? But those civilizations only try to colonize once per 100K years? And, at the same time, their colony ships take tens of thousands of years to reach their destinations? I have a hard time imagining ways in which all of those are true at once.
  - foerbert 5y ago
    I'm not sure why you see this as so bizarre. This seems like a fairly conservative estimate across the board, intended to be used to produce some kind of lower bound, rather than be an expected case. This is a pretty common and normal idea. Is it that you think the technological civilization duration is not conservative? Remember we're talking about a civilization that can cross the galaxy here. They can show up in a star system and throw habitats across any planets, moons, or asteroids they find appealing. They can also set up whatever number of space structures they want. What exactly do you think is so likely to utterly extinguish this species in every star system within 100M years? The long duration between colonization events is not only highly conservative, it also functions here to allow any particular civilization to be pretty irrelevant. Even if some crazy war breaks out within a star system, a single surviving habitat is enough to allow the next colonization to still occur. So, yeah? It all strikes me as a pretty normal conservative estimate intended to let them figure out some kind of reasonable lower bound here. All pretty normal stuff.
    - user-the-name 5y ago
      What is "conservative" about a civilisation lasting 100 million years? That is literally astronomical. That about twice as long as grass has existed.

throwaway316943 5y ago

I’m not a fan of galactic settlement simulations mostly because I think they simulate the wrong thing which is rate of diffusion. This treats the civilization as a static thing that simply spreads out at the edges. Compared to the history of human civilizations this is clearly unrealistic. The question to answer is what happens within the already colonized systems over time. How often would breakaway civilizations appear, wars, extinction events, mind upload cults, Luddite revolutions, stagnation, etc. Filters abound. The great civilizations of Earth’s past have succumbed to similar fates and we’ve only progressed by starting over again and again.

JackFr 5y ago
It’s true that filters abound but the idea that we’ve had to start all over again is Whig history. It’s been a continuum. That being said I agree with your main point. The difference in worldview, ethics, where man sees himself in the universe over the course of our history (let alone pre-history) has taken dramatic and difficult to model changes. Imagine the worldview of the builders of the Great Pyramid vis a vis our own. (And then remember that Cleopatra was far closer in time to us than them.)
- QuesnayJr 5y ago
  Isn't it the opposite of Whig history? I thought Whig history was the idea of continual progress.
  - throwaway316943 5y ago
    Yes, thank you, that’s essentially what I’m arguing against. There’s no reason galactic civilizations should continually progress especially when each settled system is effectively cut off from its parent by light years of distance.
    - stubish 5y ago
      I think it will depend on how stable the culture is when it gets that far. Will our language become static, now we have the printing press and Netflix? We are still changing, where books and films from 80 years ago have not aged well due to social attitudes. But if it stabilizes, maybe the culture stabilizes, and maybe it can be stable enough for million year time frames. It might not even happen here.... maybe in a million years after the first colony or three has happened one of them will develop a culture capable of becoming galaxy spanning. I think it is worth noting that a new settlement will not be completely cut off from its parent. I imagine a new settlement around Alpha Centauri will be greedily consuming Earth media for quite some time, delayed by just a few years, until it progresses far enough for its own exotic drammedys to be consumed by Earth.

aj7 5y ago

It seems like it would be trivial for a civilization to have a policy of no electromagnetic emissions so no signature at all. 10km/second is absurdly slow. Who would want to make the trip, and condemn thousands of generations of her progeny to bizarre ship life and culture?

signal11 5y ago
> Who Civilizations aware of imminent extinction-level events may choose to do that, similar to how shipwrecked sailors may fashion a raft and "risk it" in the off-chance they survive.
- edgyquant 5y ago
  But why would they go off to a different system instead of just colonizing around their sun or even other planets close to them? If it’s their star is gonna blow why would they go any further than the nearest star?
  - signal11 5y ago
    Depends on the ELE. There are several which can swallow entire solar systems, and the nearby stars may not be hospitable. Maybe the endgame is to find a habitable planet?
Aeolun 5y ago
> Who would want to make the trip, and condemn thousands of generations of her progeny Presumably the people that do this do not think ship life will be that bizarre. I’m frankly more concerned about the sustainability aspect than how daily life will work.
spywaregorilla 5y ago
Ship life would probably be better than the lives many people experience today, in first world countries. There's also probably some super advanced VR by that time.
keiferski 5y ago

marcus_holmes 5y ago

Colour me a little disappointed. Firstly, this seems obvious. The conclusion of "even really slow spaceships will colonise the galaxy given enough time" is almost mind-numbingly banal. Secondly, the parameters seem to be chosen in order to produce an "interesting" propagation pattern, rather than based on any actual data or guesstimates (I know there is no data, but making shit up is no substitute). Thirdly, it doesn't answer the big important question of "where are they?" (as fnord77 asks). Saying "even really slow spaceships will colonise the galaxy given enough time" brings us immediately right back to "how much is enough time to colonise the entire galaxy?" which they then say is ~1 billion years. Fourthly, but they're not here. So the answer to that question must be "over ~10 billion years". So either the simulation is wrong (because it takes longer than ~1 billion years) or it's pointless (because the only other explanation is that there has been no such colonisation effort, so why are we modelling it?). This wasn't addressed at all. Fifthly, this assumes that all solar systems can be colonised, and will produce another colony ship 100,000 years later (for inadequately explained reasons). Given that we know a fair bit about the actual galaxy (though the simulation doesn't look anything like our actual galaxy), why didn't they run the simulation on our actual galaxy, and exclude the stars that we know can't be colonised (because red giant, etc)? Finally. Is this the state of cutting-edge research on SETI? This wishful-thinking make-believe "look what I made Mum!" stuff? If this was a bootcamp dev showing off their WebGL modelling demo, I'd be impressed. 'nuff said. Sorry to be harsh, but... really? this is it?

deleted 5y ago
[deleted]
avaldes 5y ago
> Finally. Is this the state of cutting-edge research on SETI? This wishful-thinking make-believe "look what I made Mum!" stuff? If this was a bootcamp dev showing off their WebGL modelling demo, I'd be impressed. 'nuff said. Sorry to be harsh, but... really? this is it? I mean, when all you have to work is literally nothing all you can do is speculate. It is disappointing but what can they do but throw everything at the wall and see if it sticks.
- 5y ago

rho4 5y ago

> one of the comments on the article site: "I have yet to see a convincing argument why advanced civilizations would need to constantly expand like bacteria in a petri dish." E.g. to escape from violence, conflict and war.

pfdietz 5y ago
The assumption there is that advanced civilizations only do things that they "need" to do. That's not true of any civilization at any point in history. Would an advanced civilization find value in colonization? Very likely -- colonization (biological or machine) is likely the cheapest way to explore another stellar system in detail, with explorers manufactured or born in situ.

h2odragon 5y ago

"looking for technosignatures" .. Which'd be what? AM radio transmissions? Spread spectrum stuff? How would we have interpreted our own "technosignature" 100 years ago? Compare the efforts it takes to talk to Voyager vs SETI: unless the aliens are talking to us in the way we are looking for we're not likely to see them. I won't even get in to the blithe assumptions about the ease of interstellar travel; Charlie Stross has a lot to say there and all said better than I could.

unnouinceput 5y ago
You can safely assume that one of the fundamental forces of our Universe is the same, namely electromagnetism, which means that yeah! AM/FM radio would be among those signatures.
- h2odragon 5y ago
  Let me try to express that better: When we were just figuring out FM radio ourselves, i don't think we'd have been capable of recognizing a modern spread spectrum WiFi transmission as a signal. It would have been an elevated noise level and puzzling, perhaps. So the next hundred years of human advance, I expect, will bring similarly transformative changes in the ways we communicate and the shape of our "technosignature". Our expectations for what other species might be doing don't seem to be informed by the things we know we've done.
  - scotty79 5y ago
    Or in next 100 years we might figure out how to use neutrinos for communication and find out that galaxy is actually quite busy place, it's just nobody uses electromagnetic waves for comms same way they don't use smoke signals.
  - angus-prune 5y ago
    Related to this. We are basing what we consider natural phenomena on our observations of the galaxy. If we were to flip the assumption from life being rare to life being pervasive, what assumed natural phenomena could in fact be evidence of life? There is precedent for this on Earth. We are just startign to discover how much The Amazon rainforest is actually a human creation and basically a massive multi-generational bioengineering project. This is not a serious position fo mine, btw, I know that we can track most astronomical phenomena back to fundamental laws of nature. But equally there are some massive astronomical myseteries (dark matter/energy, certain stars being more/less common than expected etc) and I can't quite dismiss the wonder that our baseline assumptions have been tainted by this assumption.

gmuslera 5y ago

It may be the Dunning-Kruger effect for civilizations. The ones that didn't reach the stage of interstellar travel think that is trivial to travel and settle in other star systems. But the more advanced ones may have different ideas, or think that it is a waste of time/resources compared with some more interesting alternatives.

tomiplaz 5y ago

There's a great video on this topic from the Cool Worlds Lab channel: https://www.youtube.com/watch?v=c7OeeGcMFMc https://www.youtube.com/watch?v=c7OeeGcMFMc Taking into account ship ranges and settlement lifetimes produces very different results (15:36 in the video).

unnouinceput 5y ago

Looking at the video, and assuming that indeed that's how a Type II->Type III civilization spreads around, I've counted 2 full rotations of the original star. One rotation in our galaxy takes 230 million years (https://en.wikipedia.org/wiki/Galactic_year https://en.wikipedia.org/wiki/Galactic_year) which means even if we start today to spread around would still take half a billion years to populate the galaxy. Now if only genetics would deal away with aging to be around when that happens :).

cletus 5y ago

A lot of thought has gone into this area. I think the parameters of this simulation are too conservative, which is perhaps the point. Several issues: 1. Speeds are likely to be much higher. We largely rely on chemical propulsion plus gravity slingshots. For a sufficiently advanced civilization you're likely to concentrate a star's power to provide significant outward propulsion (and braking!) without the mass concerns of carrying reaction mass; 2. Once you've built one of those starships, it will likely continue on its journey after stopping at a new system to colonize and resupply. It's not clear to me if the simulation assumes this. Given the time frame of 1B years it seems not; 3. Stars in the Milky Way rotate at different speeds. Like in a few hundred thousand years we'll have a new closest neighbour for awhile. This potentially increases spread as the colonized systems drift further away extending their reach over time; 4. The simulation just looked like a collection of stars rather than, say, a spiral arm galaxy. So a realistic timeline is closer to 10M years than 1B years. I'm firmly in the camp that believes the speed of light is a hard limit. FTL drives and variants (eg wormholes) just seem to be wishful thinking by people who don't understand function domains (eg negative mass). Assuming that, a galaxy-spanning civilization is unlikely to be a civilization in the sense we understand it given that it might take you >1M years to cross from one side to the other. That's not really a problem for detecting such civilizations as the source of detection isn't likely to be EM transmissions (as the SETI program began looking for). Instead, it's likely to be the IR signatures of Dyson swarms. Short version: in space, the only way to cool down ultimately is to radiate that heat away into space. That radiation is completely dependent on the temperature of the object radiating heat. For any normal range temperature that's firmly in the IR range. So, if a star has a Dysown Swarm, it'll shine incredibly brightly as an IR source with a very low amount of visible light. Can you spot one such star? Possibly not. But an entire galaxy? You're likely to be able to see that from 1M+ LY away, easily. Given the small amount of time this would take to eventuate, in cosmological terms at least, the reason we haven't been able to detect any highly-advanced civilizations within our light cone is quite simple: there aren't any.

s1artibartfast 5y ago
#3 was very much included in the simulation Also, I don't think it was meant to be a fastest or even nominal case simulation. It could clearly be run with different inputs

PaulHoule 5y ago

Their propulsion speeds are low (today’s technology but you’d need D-D fusion or antimatter to keep warm) but 100 Myear survival time is hard to believe. I also don't believe a species that masters slow interstellar travel would care about stars and planets. Most of the mass which could be exploited by life is floating between the stars in the form of comets and if you could "live off the land" out there you could create millions of miles of apartment buildings and shopping malls. Why trek into an inner solar system and build yourself a space shuttle that can land full of fuel and then take off when you are settled into a space lifestyle?

shakezula 5y ago
> I also don't believe a species that masters slow interstellar travel would care about stars and planets. > Why trek into an inner solar system Why venture off to unknown shores to build yourself a farm when you're settled into a comfy European lifestyle? Although we only have ourselves as a data point, I think that natural curiosity is a strong evolutionary trait that we developed, and it's not a huge stretch to assume that other lifeforms would develop the same curiosity.
- throwaway316943 5y ago
  I imagine an interstellar civilization would have this to say about planets: “A nice place to visit, but you wouldn’t want to live there”

bamurphymac1 5y ago

Early bird gets the worm.

carapace 5y ago

Two things: 1) Check out "The Millennial Project": https://en.wikipedia.org/wiki/The_Millennial_Project:_Colonizing_the_Galaxy_in_Eight_Easy_Steps https://en.wikipedia.org/wiki/The_Millennial_Project:_Coloni... > The Millennial Project: Colonizing the Galaxy in Eight Easy Steps by Marshall T. Savage is a book (published in 1992 and reprinted in 1994 with an introduction by Arthur C. Clarke) in the field of exploratory engineering that gives a series of concrete stages the author believes will lead to interstellar colonization. Many specific scientific and engineering details are presented, as are numerous issues involved in space colonization. I find the cover image of a green galaxy is very inspiring! 2) Due to the nature of exponential growth, we will eventually feel a population crunch when reproduction overwhelms the rate of expansion. This is true even if we invent FTL ships. The crunch would be delayed (perhaps for millions or billions of years) but it is inevitable.

biggestlou 5y ago

I'm still looking for intelligent life on this planet!

katabasis 5y ago

The simulation includes this assumption: > Technology persists in a given settlement for 100 million years before dying out Seems wildly speculative to me. Our own civilization has only been around for a tiny fraction of that time and future prospects are already looking pretty uncertain. And if we lived in a galaxy where civilizations had this kind of longevity, one would think we'd see some evidence of potential signals out there. My own pessimistic take on the Fermi Paradox is that life and intelligence may not be very unique but there is no reason for them to be long-lived either. Most civilizations are probably just a "flash in the pan", existing too briefly and separated by too great a distance to ever come into contact with another one (or even learn of another's existence).

throwaway316943 5y ago
My optimistic take is that advanced civilizations capable of travelling the galaxy don’t spend their time hanging around planets and stars for the same reason we no longer hang around caves and fire started by lightning. They’ve mastered fusion and matter transmutation so they just build their own habitats and energy sources wherever they want.
- martinflack 5y ago
  > They’ve mastered fusion and matter transmutation so they just build their own habitats and energy sources wherever they want. ...and maybe not even within the four dimensions with which we're most familiar.

lapp0 5y ago

centauri-dreams.org ... Hmm, more like pipe-dreams.org

aaroninsf 5y ago

ITT: many propositions and counter-propositions constrained by presumptions that next-level civilization and its modes of being and interacting with the universe are "necessarily" much like our own. One example: "upload" and "simulation" do not have any predetermined relationship to the material behavior of a species engaged in it. The mapping between agency in any presented reality and the species-consensual one is arbitrary and the distinction between simulation and reality might just as well be framed as a question of sensorium cum UX. Very very little can be extrapolated upward from our own limitations and constitution either as individuals or societies or species. An even deeper example: fundamentals like the relationship to time may be radically different. It may not just scale, it may be fractal; and the notion of what constitutes agency and the locus of selfhood and identity, and hence self-interest, may be distributed emergent and predicated on an interplay between ant-and-colony at multiple levels, each of which is fully "conscious" and intentional in the sense we understand those things, at different time scales. What does a third grader know of amortization? We are not even out of the womb as a species.

xwdv 5y ago

One thing missing from this to help get a sense of scale is a running count of the number of souls populating the galaxy. Would be great if they can also show “settled” population and population in transit to some destination for settlement.

tectonic 5y ago

"Technology persists in a given settlement for 100 million years before dying out" That seems wildly optimistic.