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.
I feel a need to add an important extra wrinkle. The front line of progress and growth in all things is driven by those who are pursuing progress and growth. If an upload cult arises in a planet, and 90% of the populace retreats into simulations, the remaining 10% are still around and we be selected to be exactly those people most invested in the material universe; within a few years (not millions of years, certainly) there’s a good chance they’ll be considering expansion. Or, consider how often new civilizations are formed by small populations of refugees from intolerably oppressive larger civilizations. Something like a war, extinction event or ecological difficult is similarly likely to prompt a desire for expansion as it is a total collapse.
Science fiction is full of sentences of the form, “The Klaatu were an alien race who colonized the galaxy a million years ago but have since moved on.” I always roll my eyes at this. Almost no matter what the Klaatu are or what they care about, there would be some group of them remaining. And the only Klaatu we would see would be the descendants of the ones who stayed. Giant galactic civilizations made of individuals are unlikely to make coherent collective decisions with no dissenters for the same reason our single planet (with much less serious communications obstacles) never makes unanimous collective decisions.
What if 90% of the populace retreats into simulations, but in such a way that the remaining 10% have no political power and no industrial base, because that all remained with the majority? Hard for the non-uploaders to expand in that case.
That's quite contrived in my opinion. How can people uploaded into a simulation maintain that level of control in the physical world for any durable period?
They have to keep up all the computing infrastructure running the simulation, and deal with long-term threats like geological activity and asteroids. That requires having and maintaining considerable technology out in the real world, and if only a mere 10% refuse to enter the simulation, then that minority may not get to benefit from spacefaring technology, or have the capital or industrial base to develop their own.
In fact, since spacefaring presents a threat (kinetic bombardment) to any planetary-bound species, then that majority who choose to enter the simulation may want to expressly prevent the minority from leaving the planet.
This is obviously not impossible, but we are now in the realm of adding clauses to an already rather specific scenario, each clause adding another degree of improbability. (The odds of "an upload cult arises on a planet" is by definition greater than "an upload cult arises on a planet AND actively presents anybody else on the planet from ever leaving.)
I think the metaphor to look to isn't necessarily even human civilizations spreading around the globe; it's life spreading through the planet to colonize every niche out of which the slightest scrap of energy can be extracted.
Wouldn't it be a lot easier for the non-uploaders to, you know, just pull the plug? Or change the input to the digital existances in a way to simulate a reality "outside"?
No, because – as I mentioned above – the uploaders would still maintaining all kinds of technology to monitor and control the outside world in order to ward off any threats (natural disasters, sabotage from the non-uploaders) to the computing infrastructure on which the simulations are running. If the majority of society chooses to upload, then that suggests that such protective infrastructure is already so stable and advanced, that the non-uploaders would be powerless to simply "pull the plug".
It's an interesting question. How do people maintain control now? In general, it is not through physical control. We have institutions, we have "manufacturing consent".
We have those in a negative sense. Manufactured consent is mostly about directing motivation towards wars of control and acquisition and preventing other activities - including the peaceful development of sustainable energy, which is finally happening fifty years after it could have, and non-corporate non-military access to space on top of a non-corporate internet, neither of which are happening at all.
Manufacturing positive consent for a billion-year project is - obviously - a completely different kind of problem.
POTUS himself may be absent from Africa but not from physical reality, and the physically real resources under their command certainly aren’t absent from the various corners of the world.
I don't understand your argument. How much control do you think the White House exercises over chimpanzees? Your hypothetical chimpanzee is completely correct.
Change the “upload filter” to “total upload filter” smaller chance but still relevant. Also it was a silly sci-fi example, I’m sure sufficiently advanced societies can think up better forms of planetary dead ends.
This is far more complex to model, and near impossible to. I wouldn't expect to see this anytime soon.
But to give you some hints, breakaway civilizations would likely happen all the time. Every space program has issues with astronauts not following orders simply because the astronauts internalize the idea of "what are they going to do? Come get me?" This is frequently talked about in settings where they are discussing Moon and Mars colonization. A Martian colony won't really belong to the US/China/EU/whatever for very long. I'd expect something very similar to Red Mars/The Expanse.
Another big reason for this will simply be time of light communication delays. Between Earth and Mars that's 8-15 minutes one way. It is highly impractical to control a territory when communication takes so long, they will effectively become independent. We've seen this historically too. Colonies operate drastically differently than their home countries. Being so far away it is difficult to communicate and cultures will diverge, especially considering that their day to day lives will be drastically different. Different needs creates different cultures. But luckily this distance also makes war difficult between two planets. You have months to respond.
> Every space program has issues with astronauts not following orders simply because the astronauts internalize the idea of "what are they going to do? Come get me?"
From the script to Casino:
> Every couple of weeks I used to send Marino back to the bosses with a piece of what I made.
> Not a big piece, but fuck them, what did they know? They were fifteen hundred miles away... and I don't know anybody who can see that far.
On the other hand...
> Between Earth and Mars that's 8-15 minutes one way. It is highly impractical to control a territory when communication takes so long, they will effectively become independent.
This is totally wrong. Between Earth and Earth, empires have exerted effective territorial control while communication one way took weeks. A 15 minute delay in communication is meaningless. The problem is the difficulty of traveling, not of communicating.
> empires have exerted effective territorial control while communication one way took weeks.
That's because the effective territorial control was not exercised by the central government of the empire, but by territorial governments that were on the spot and that had pretty much complete authority to act on their own initiative without getting permission from the central government. They only had to meet very general policy goals. So the speed of communication with the central government was not relevant to the effectiveness of the territorial control.
The question is whether a territorial government on, say, Mars would have the same loyalty to the central government on Earth that, say, British territorial governors had to the British empire. Without that loyalty on the part of the territorial governments that are on the spot, there is in fact no way for the central government to effectively control territories.
True but the reason these territories respected the metropoles laws is because they were aware if they didn’t the metropole had the resources to overrun them if they were upset enough. The same will be true of any off world colony for the foreseeable future.
> the reason these territories respected the metropoles laws is because they were aware if they didn’t the metropole had the resources to overrun them if they were upset enough
I don't think that's true, since, as godelski points out, in a salient historical case where the colonies did not respect the home empire's laws--the United States of America--the home empire did not have the resources to overrun them. The British ended up learning similar lessons in South Africa and India later on.
I think the main reason colonial governments respected the home empire's laws is that the territorial governors and their personnel were loyal to the empire; they believed in the empire and its aims. When that loyalty goes away, as it did in the USA, the home empire can't do much about it.
> The same will be true of any off world colony for the foreseeable future.
You must be joking. If the British empire was unable to enforce its will on the United States, with only an ocean separating them, how could an Earth empire possibly enforce its will on a Mars colony, with tens of millions of miles of space separating them?
This does not take away from what I’m saying, like at all. When territories are unable to be held on to they are no longer territories of their metropole but independent states. I also like how you chose the US as an example to claim I must be joking.
1. The US territories existed in a time before our current technology which allows one to send drones to other planets
2. The US was heavily settled by the time it gained independence it could hardly be called a colony anymore at that point.
3. I said the foreseeable future, not indefinitely. Sure by the time there are millions of people on another world with their own economy, militias and legal tradition going back centuries that territory could make a bid for true independence but that won’t be the case for centuries at best. Any territory doing so anytime soon will seriously lack the industry and manpower to even hold their own territory against a large Earth based nation capable of colonizing other worlds.
> When territories are unable to be held on to they are no longer territories of their metropole but independent states.
In other words, you redefine words to avoid admitting any flaws in your argument. The United States was a territory of the British Empire. The British Empire failed to "overrun" them when it got "upset enough" (your words). So your argument fails for this case. You can't change that by redefining words.
> The US was heavily settled by the time it gained independence it could hardly be called a colony anymore at that point.
Excuse me? Being "heavily settled" in no way prevents a place from being a territory of a foreign empire. The population of India during British rule was far larger than the population of the British colonies in North America in the 1770s. That didn't stop India from being a territory of the British Empire.
> a large Earth based nation capable of colonizing other worlds
Colonizing other worlds is a lot easier than controlling them from tens of millions of miles away once they're colonized. The former just takes enough people willing to make the trip and a spaceship that can make the journey. The latter takes the ability to project overwhelming military force across that distance, which is a lot harder.
Also, I am not saying that, for example, a Mars colony must become independent. I'm simply saying that whether or not it does will depend on the motivations of the people in the colony. If those people remain loyal to Earth, the colony will. If those people stop being loyal to Earth, they will start acting independently, and there won't be a lot that Earth can do about it.
I'm not convinced that's true. The New World exists for exactly this reason. The British were not able to sustain a war half a globe away with the Americans. It is incredibly expensive (hell, even the French supporting the US took a big hit). All a Martian colony would need to do is play guerilla warfare and wait it out. There's plenty of history to suggest that this is an effective strategy.
Sure by the time there is a huge population of basically nations on Mars that may be the case but that isn’t in the foreseeable future. The New World existed as colonies for centuries before it had the ability to become independent and even then that more to do with Napoleon for South America and the rest of the world wanting to take Britain down a peg for. The US.
> The New World existed as colonies for centuries before it had the ability to become independent
No, many of the British colonies had the ability to become independent fairly soon after being colonized. The key variable wasn't how capable the colonists were but how interested Britain was in controlling them, and that varied widely from colony to colony, depending on who in Britain had to exercise the control. Some, like the British peers who had ownership interests in New York and Virginia, were control freaks and wanted to exercise all sorts of detailed micromanagement of their colonies. Others, like Penn with Pennsylvania, basically let them do whatever they wanted and didn't bother much about it. And even in colonies like New York and Virginia, once you got away from the coastal cities or river ports that were easily accessible to British ships, the level of British control dropped drastically. The British couldn't do much at all about up-country backwoods farmers and trappers, who basically didn't care what the British or the colonial governments did since it couldn't really affect them.
What didn't crystallize until the 1770s was the political unity between the colonies behind an explicit declaration of independence. Which was, in large part, a product of the British, after the end of the French and Indian War, deciding that the colonies had already gotten too independent and needed to be reminded that they were still British subjects. Which didn't work out very well.
> that more to do with Napoleon for South America and the rest of the world wanting to take Britain down a peg
All of which happened after the US had already become independent. So it's irrelevant when looking at how the US became independent.
It is true that the British were still dealing with the French in Europe and that this limited their ability to project power in America during the US revolution. (The Americans also took full advantage of this by allying with France.) But that just illustrates my point: empires aren't omnipotent and can't just magically project power whenever and wherever they want to.
Thank you, this is what I was trying to suggest. That these localized governments, while loyal to their empires, operated fairly independently (which should be fairly obvious for similar reasons to space. Which travel times are actually similar). Hopefully your comment has helped clear some confusion up.
> Moreover, Mars would probably be utterly dependent on earth for multiple generations.
Probably not. The reason Mars colonization is difficult is because they have to be self reliant. It isn't like expanding in the past where people could live off the land or barter or steal from the native peoples. There are no natives on Mars. There is no native vegetation nor is the land adequate for farming/cultivating.
In the past colonies could rely on these things and exploit them. Mars is very different. If you aren't self sufficient on Mars you will die. Period. Astronauts visiting Mars, just visiting, will have to figure this out too because they can't just land and come back. They have to wait a full year for the planets to realign (this is also why it is difficult to subjugate Mars because it isn't just about the travel time, it is about the orbits being aligned plus the travel time).
> They have to wait a full year for the planets to realign
This actually shouldn't be true for much longer. The only reason it's true now is that we don't have spaceships that can produce constant thrust for the entire trip; our ships spend most of their time in free fall, which, as Robert Heinlein pointed out decades ago, is the equivalent of floating down the Mississippi on a raft. As he said, what we need are the equivalent of sailing ships: ships that can put out a constant thrust, even if it's small, for an entire trip. Even a thrust of 1/100 gee, which is well within our technical capability if we get serious about things like ion drives, would greatly reduce trip time to Mars (and would reduce trip times to more distant planets even more, since the advantage over free fall increases as the distance increases) and would open up a lot of options for travel that we don't currently have.
Note that this doesn't change the fact that humans on Mars will have to be self-reliant; payload mass is still payload mass and a spaceship just won't be able to carry enough of it to Mars to supply life support for any length of time staying there. Sending unmanned missions in advance might help, but I don't think even that would be enough.
> our ships spend most of their time in free fall, which, as Robert Heinlein pointed out decades ago, is the equivalent of floating down the Mississippi on a raft. As he said, what we need are the equivalent of sailing ships: ships that can put out a constant thrust, even if it's small, for an entire trip.
Sails don't do that. In terms of propulsion, they're exactly the same as pole-less rafts. Ever heard of being becalmed?
The propulsive force is not as controllable as it is for a low-thrust rocket, true. But Heinlein was not claiming an exact comparison.
> they're exactly the same as pole-less rafts.
No, they're not. Pole-less rafts don't have sails.
> Ever heard of being becalmed?
Ever hear of missing the point?
Yes, sailing ships can be becalmed. But they can also not be becalmed. And sailing ships that were not becalmed created a worldwide system of trade. Pole-less rafts would not have been capable of doing that.
You statement doesn't actually confer confidence that you understand space propulsion. No fret. This is something most people don't know about, but I guess a lot of people speak about it because it is cool. We already have ion drives. But butterfly farts won't get warheads to Mars faster. Your burn rate will increase dramatically depending on Mars/Earth alignment. This again adds to the cost that we've been talking about above and how historically oppressors have had a difficult time sustaining combat with subjugated people, and cost is directly proportional to distance. It's a matter of will mostly and how much they get from those subjugated people. But even with the best technology we can see ourselves building within the next decade or so we're talking 3 months on a good alignment (current is 9 months). For comparison, Columbus was on the sea for 36 days. People saying that "oh, it was just like ye old times" don't realize that we're still talking about substantially longer time frames and substantially higher (proportionally) costs of travel.
And as for robotic warfare, I'll give the same answer to everyone that asks how guerillas fight tanks and jets. 1) you can't rule the dead, 2) international trade looks down upon countries that commit genocide, 3) genocide is typically pretty expensive.
> Your burn rate will increase dramatically depending on Mars/Earth alignment.
Why? I am not talking about keeping trip time constant. I am just talking about significantly reducing trip time compared to free fall. That is easily done with a low thrust ion drive; even a hundredth of a gee makes a significant reduction in trip time, and the longer the distance, the more the reduction in time even holding the thrust constant (since the trip time now increases only logarithmically with the distance instead of linearly). And that makes trips more feasible even when the planets aren't in alignment.
> even with the best technology we can see ourselves building within the next decade or so we're talking 3 months on a good alignment
Now it's you who aren't conferring much confidence in your knowledge. Below are some numbers (travel times are one-way). I've even included numbers for 1/1000 gee to show that even those numbers are much better than the free-fall numbers.
Closest approach: about 60 million km (6 x 10^10 m)
Free-fall travel time: 180 days
1/100 gee travel time: 18 days
1/1000 gee travel time: 57 days
Furthest away: about 400 million km (4 x 10^11 m)
Free-fall travel time: 1200 days
1/100 gee travel time: 47 days
1/1000 gee travel time: 148 days
The free-fall transit time for closest approach is taken from the Wikipedia article on free-return Earth-Mars trajectories; I have used the shortest time that appears to have a reasonable return trip (though the return trip transit time is longer). [1] Free-fall transit times for furthest away are taken by multiplying the closest approach time by 6.67, which is probably somewhat of an underestimate (it assumes straight linear dependence of trip time on distance, without confirming that there actually is a viable transfer orbit with that transit time).
1/100 gee and 1/1000 gee transit times are obtained by using the formula t = 2 sqrt(d / a), where d is the distance and a is the acceleration. This formula assumes constant acceleration to the halfway point, then turnaround and constant deceleration the rest of the way. (I also adjusted the units in the answers above to days instead of seconds, which is what the formula I just gave gives; I rounded up all fractions.)
I have ignored orbital maneuvers and takeoff/landing at both ends for all travel times.
Which was by no means the longest, or even a particularly long, voyage for the time period. Vasco da Gama was at sea for more than three months at a time during his voyage around Africa to the Far East and back. So was Magellan during his round the world expedition.
> Most of the same tactics used to control colonies could be used to control Mars.
Those tactics only work when backed up by a credible threat of overwhelming force. I do not think the Earth will be in a position to bring overwhelming force to bear on a Mars colony. It's a lot harder to do that across tens of millions of miles of space than it is to do it across an ocean. And even across oceans on Earth it often doesn't work.
> Mars would probably be utterly dependent on earth for multiple generations.
I'm not so sure. We have barely even started exploring Mars; we have no idea what resources exist there. We are still discovering new resources here on Earth; I would expect that humans on Mars would be doing the same there.
One thing I seldom see mentioned, too, is why would a K3 civilization use easily detected communications like radio or broadly focused light sources? If we launched Voyager 3 (for lack of a better name) next decade, would we use primarily always-on, omnidirectional radio? Would we use a laser? Maybe we'd use a tightly focused, burstable digital radio system. What about next century? Are we simply looking largely for the wrong things?
The tightly focused radio beam would still leak into surroundings and scatter off of things, and would thus still be detectable.
Thing is, we still don't know yet what matter and energy actually are. We still don't understand the nature of spacetime. We have a lot of physics to discover. Those other civilizations might have discovered physics in different order. They might be communicating using phenomena we have no idea exist.
It's not right to assume that advanced alien civilizations will be using any technology similar to ours.
A radio observatory on Earth might be using a fiber optic connection to connect to the rest of the world but it's still looking at natural radio phenomena. It doesn't matter at all what a civilization might use as a backhaul, their Space iPhones could use SubspaceWifi, but their radio observatories will be looking at natural molecular hydrogen emissions.
For an interstellar beacon signal radio is pretty good. Lots of natural phenomena are radio sources, CMB is radio, and a lot of things opaque to visible and near visible light are transparent to radio. So a radio beacon has a good chance of being detected just because any civilization that discovers radio astronomy can stumble across it.
The idea that SETI would ever detect I Love Lqwynngh'tch reruns from an ETI has always been ludicrous. Even our most powerful radio telescopes (by sensitivity) wouldn't be able to detect television or radio broadcasts even a lightyear out from Earth. The only interstellar signal we (or another civilization) will ever detect are very intentional directed signals.
If you had an omnidirectional radio source detectable from interstellar distances you could use it once as it would fry itself and anything around it pretty quickly.
Your comment is interesting, but thinking about it, this is the most likely thing to happen:
Any technological advance in interplanetary travel speed or new technologies of renewable and easy source of energy, would promote expansion. The new arrivals to an empty planet could start all over again, claim the resources as theirs, organize their own laws. And if they are overcome somehow move to other planets and start all over again...I think there is wave coming our way if we think about it.
Yes my point is that each system colonized becomes its own independent case subject to destroying itself or regressing or becoming antagonistic towards its parent civilization. Think back pressure or resistance. The question I’m asking is at what point does that resistance turn the tide of expansion.
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.)
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.
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.
There are lots of questions to answer. Some can be modeled more easily than others. This one is pleasant because the model is simple enough for a broad audience to reason about, and the visualization is straightforward.
There's a factor that would make a difference, a question of identity. A civilization grown out of a migration and only possible thanks to advanced science would look at some things unlike any other that we know.
they assume 1 successful colonization ship per 100k years. This might take into account periods of stagnation and Luddite revolutions and such. Sentient beings do various weird thing but they do them fairly quickly.
The history of human civilizations is a blink in the eye compared to the history of the human race. And compared to the time scales of the simulations they run. So I wonder if maybe those filters end up as noise when we’re talking about filling the galaxy. History is less of a detailed story and more of a fundamental force.
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?
> 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.
Well they don’t have absolutely nothing. We know how much it costs to get mass into orbit, we know the launch cadence we’re capable of, we know how long it takes to build huge vessels like nuclear powered submarines and aircraft carriers, we have realistic proposals for propulsion techniques that could get us to our nearest neighbour. You could make limited extrapolations from these points to figure out how much it would cost and how long it would take to build a colony ship. That would tell you a bit about the conditions necessary to begin colonizing the galaxy and you’d be able to tell if those conditions were likely to occur in the near future. We know how long it took to colonize the Americas so you could adjust that data. That should give you both the rate at which you can create colony ships and how long it takes for a colony to reach the point that it can begin building them.
It seems like this is an entirely different question than the one evaluated in the article.
IT is a an interesting question, but it seems weird to fault the article for not being something different.
Alternatively, one could argue that all of this data is worthless in predicting the industrial capacity of spacefaring culture, at least 100,000 years more advanced. Im guessing this is why they didn't bother.
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?
> 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.
> 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).
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.
> 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.
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.
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.
> Remember we're talking about a civilization that can cross the galaxy here.
That would be earth at the current point in time. Given 100k years I’m sure we could fabricate a huge colony ship, and accelerate it to 10km/s. What we won’t be able to do is throw up habitats all over the solar system.
By that point all your tech is thousands of years old. It seems unlikely it’d be capable of doing more than drop you off on whatever planet you were aiming for (or keep floating around, if it’s a lifeless husk).
Again, we're talking about a civilization that is colonizing the galaxy here. They would presumably have habitats and people strewn all over the star systems they colonized. What do you see wiping them all out entirely so regularly that 100M years as an average is so optimistic?
And it doesn't even need to be a single civilization. You only need a civilization to exist capable of launching a new colonization venture every 100k years, or whatever the average rate they assumed was.
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.
"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.
We can capture all known forms of interstellar radiation, we have a baseline of background noise, and we can see if they are chaotic or structured. I don't believe technosignatures are indistinguishable from noise.
I mean sure, sci fi mode engaged, aliens may have ascended our own physics and may use quantum entanglement or subspace for communications and the like, in which case we wouldn't know. And our own signals too will get weaker and garbled over time; I'm not sure if even our own radio broadcasts 100 light years away are discernible from the background radiation of all the stars.
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.
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.
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.
Or Galaxies are the ultimate mega structure and dark matter is merely the observable signature of the gravity modification tech they use to hold them together.
I like this interpretation of the Fermi paradox the most: We're a dumpster-dwelling species barely qualifying as sentient compared to the species whose dump we inhabit.
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.
It looks like using only old technology we can detect the signal and identify it as a artificial signal, but it would be very hard / impossible to decode.
You can listen to all the radio frequencies at once, from low AM ones up to dozens of GHz using inexpensive radio components - it's how bug hunters you see in movies work, they just measure electromagnetic waves, regardless of their wave length.
Granted, you'll not be able to differentiate between them, only that they exists. And at this point of searching for those signatures that's all you need though. Also Marconi was listening to lightning strikes generating radio waves using his radio, and that was over a century ago. Lightning strike generates radio waves all over the spectrum, so we had this capability right from beginning.
One of the current technosignatures are em radiation indicating Dyson spheres or swarms around sun's. Another is molecules in planetary atmospheres which are only known to arise from industrial applications.
> 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.
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?
> The artificial life that we create will be the ones taking over the galaxy.
Exactly. A galactic version of "core wars". If we leave any trace at all it will be our machines. Future life will resemble 3D printers in search of raw materials, not GI tracts in search of food, spores that will survive billion year voyages with infinitesimal chances of success.
That's the premise of one of my favorite sci-fi stories, The Songs of Distant Earth by Arthur C Clarke. The stuff about what-do-people-do-when-the-apocalypse-is-coming-but-kind-of-a-ways-off was cool too.
(in case anyone scrolling by is looking for additions to their to-read list)
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.
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?
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?
It wouldn't even be about colonization, because it would be infeasible to make a return trip or, unless communications technology changes (e.g. quantum entanglement magic), even phone home upon arrival. The only thing I can think of is survival of the species, survival and spread of life itself. It's not infeasible to believe that's how life on earth started - not as a spontaneous process, but a natural spread of life from elsewhere (panspermia) or a previous life form spreading the building blocks on purpose.
But life on earth has been going on for hundreds of millions of years so I don't think we'd find any traces of it.
Imagine that VR develops over the next few centuries. Millions of people engaged everyday, for 10-12-15 hours. At that point, what’s the difference between being on a ship or being on Earth?
But I don’t think it’s too far fetched. Imagine a VR system that doesn’t require wearing a helmet and can be displayed in physical space. And/or a Matrix-style direct jack into the brain. Any environment you can think of, easily accessible. Doesn’t seem that bad to me.
Beyond that, A lot of people already spend 10+ hours staring at screens here on Earth...
Does it replicate smells, tastes and touch sensations as well as just sound and vision? I spend a lot of time staring at a screen, but it's the time I spend not staring at a screen and interacting with other beings that makes life worth living.
A machine intelligence. Just turn yourself off for the trip.
Generally I'd say that the notion of a Von Neumann machine is so obvious and so effective that there's something really wrong in our guesses on how widespread intelligence is.
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.
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.
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) 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 :).
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.
> 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."
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.
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.
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.
