Hi Vincent! Just stumbled on your publication here. Are you planning on serializing your novel, or publishing it elsewhere?
If you'd like to see how I approached these ideas, I'm publishing a generation ship novel on substack one scene at a time this year. The tightness of the ecosystem and the effect this would have on their mentality is something I tried to capture. As well as the slow but inevitable effects of entropy. Everything is shiny when first boarding, but after decades, the place loses its luster!
Hi Randy, I'll check it out! I am not going to serialize my book, I will publish it as an ebook. The generation ship is more of a past setting, but I keep thinking about these details and how it would affect the society aboard.
My solution, in the story I might someday get around to finishing, is to go big. You need a big enough crew to have a viable and healthy population and big enough to run the ship, but not too big. The ship itself though, is enormous. Way, way bigger than an ordinary ship. Redundancy upon redundancy, and stocked with enough to keep a population alive during the journey to and terraforming of a new planet. 25 generations.
As you describe such a vessel will need to have extremely efficient recycling methods. Developing this capability will require a lot time. Thus, a generational ship will be former space habitat that has been outfitted with propulsive capability. Before a journey of centuries can be contemplated, a proven track record of centuries of continuous operation of orbital space habitats will need to have been achieved. The people living in the habitat will see it as their home. They have all they need here in orbit around the sun, why should they leave?
The *reason* to go to another star is for the *planets* there. What generational ships get wrong is they assume the people on the ship are like us, planet dwellers. But they are not. They are a completely different (cultural) species from us. You could build a clone of one of their habitats, outfit it with engines, put Earth people on board and set off for another system. The people who left would be Earth people, interested in finding new planet on which to live, but the people who arrive centuries later, no longer will be planet dwellers and have no interest in the planets at their destination.
I could be completely hallucinating, but I seen to recall a novel (a movement?) when I was young that suggested the Earth itself was a generation ship and that all care should be taken at all times to keep it going. Seems sort of Ursula LeGuin meets the beginnings of climate doomers.
Gerald O'Neill looked at space colonies. In his case the colonies were in the solar system with easy replenishment. After a hundred years of experience, making a closed ecosystem might be more feasible. Energy would seem to be the limit. In the solar system sunlight is readily available. For a generation ship you would need either Uranium, Thorium (fission) or Deuterium (Fusion). Those are be nature nor recyclable. Perhaps faster but smaller ships could be used to resupply the ship.
You would have to bring an inventory of fuel with you as well as raw materials. It is entirely possible than multigenerational interstellar travel is technically impossible. But even if it is possible it is precluded by cultural evolution as I noted in my other reply.
One aspect to consider is population. You would need to keep a stable population, something that I suspect is not possible. Stories along these lines often have an element where reproduction is controlled to stop runaway population growth. But I've not seen anything that considers population decline. What if living in such circumstances pushes people away from wanting to have children? That people just stop reproducing and the population declines beyond the ability to support all the required work.
You wouldn't want to build a generation ship, until you'd built a space habitat and run it for the same length of time, with careful attention to imports, and know how little you needed.
And you can practice building your habitat, a kilometre underground, first. Build a habitat down there, safe from all the giant Roland Emmerich disasters except for loss of the entire planet. 80% of the species-protection for 20% of the cost.
If we can run one of those for a century or so, then use that expertise to build a long-term stable habitat, we might be able to build one that goes somewhere.
I am skipping over the small matters of propulsion and available energy. You aren't going anywhere interstellar until the price of energy drops below a penny a megawatt-hour, so developing all that may take the time for the experiments above.
The underground habitat as a starting option a good idea, but good luck getting hundreds of people to volunteer to live in a cave for the rest of their lives!
"I'm sorry, sir, but we need you to take the laxatives for 3 days straight before you get your 1-year term in the Redoubt. The Import/Export rules expressly forbid you bringing in biological material that will be added to the balance. Also, we need your weight down by 736 grams to exactly match the guy who is rotating out".
Hang on, maybe four-year terms: and you emerge with a degree. Or a four-year tech degree in maintenance of life systems. Throw in an artist's colony, free accommodation as long as you're part of the experiment. And of course, a care-home and hospice, to simulate the Final Donations of the population to the gardens.
Generation ship is a vague term. One hundred years (everyone that started the journey would die before the destination is reached) might be possible. One thousand years might not.
Yeah, and a hundred years is a hell of a long time already for a pressurized structure with tha capacity of a medium sized city, fully isolated in deep space.
In addition to what you wrote, which is entertaining, there is an additional dimension beyond the engineering/materials issue and the social issues. That issue is evolution by natural selection. Putting a group of Homo Sapiens, with sufficient genetic diversity, onto a generation ship on a long one way journey is a perfect mechanism to achieve what speciation does on earth: Isolated populations of a species naturally, through selection pressures, genetically drift from the origin species, to the point where they eventually become separate species with their own future evolutionary paths. Think of Darwin’s finches on the Galápagos Islands, or the cichlid fishes of Lake Victoria.
Indeed, the history of Homo Sapiens itself illustrates this. Homo Sapiens has been around for about 200,000 years, but modern Homo Sapiens, us, are a more recent development, appearing about 100,000 years ago. In that time, Homo Sapiens coexisted with at least three other Hominids, Neanderthals and Denisovians being two of them. Sapiens developed in isolation from those other Hominids, arrived into their territories, and after some period of partial interbreeding, basically outcompeted the other Hominids by about 40,000 years ago, such that Sapiens is the only remaining one on the planet.
Evolution has not stopped.
Put a group of Homo Sapiens into a deliberately isolated population such as a generation ship, and they will inevitably become a new species of Homo. Indeed, depending on the length of the journey, the beings may be a new species by the time they arrive.
This is true even if they arrive on a planet that is Earth like to extreme degree. The speciation/adaptation will be even faster the farther away from Earth conditions the new planet is.
This progression is also true for every other living thing on board the ship: Plants, animals, and bacteria brought to enable growing food and providing other materials. Undiscovered viruses, bacteria, and parasites carried onboard by all species will also undergo their own mutation/adaptation cycle, with unknown future effects. All of those are going to drift and mutate as well, both on the generational ships and once they arrive. And there is basically no amount of engineering that can prevent or direct that. In fact, it would be self-defeating to even try. Life MUST adapt to its environment or it goes extinct if it can’t.
And we know what mutates and adapts faster than the genetics of Homo Sapiens: language. We still have some undeciphered written languages that are only a few thousand years old. We have evidence of many hundreds or thousands of “lost” languages. Even more recent, most non-specialist readers of modern English could not easily read old English (or even Middle English), and if they could, it is equally likely that they could not correctly pronounce the words they read if they spoke them. And the same works the other way: if you brought a speaker/writer of Old English to the modern United States, I suspect they would be completely bewildered by what they hear and read.
A generation ship has the equal risk of its inhabitants and Earthlings being relatively quickly unable to mutually understand communications from each other, as both languages are evolving in their own ways.
Given the extreme focus on stasis that the generation ship must engage in, as the article points out in detail, I suspect the likely scenario is that Earth languages will continue to evolve, while the generation ship’s language remains more or less static relative to the language state when it left.
This situation is doubly reinforced due to the generation ship’s need to rely on the state of the languages written in all of the materials on board the ship.
Have you heard of a technology called the Fusion Torch? It can recycle anything into its constituent elements. Concept invented late 1960s. Obviously the powers that shouldn't be have never allowed it to happen because it would render the commodities market obsolete, and control over that (enforced scarcity) is one of the primary mechanisms of social control over the masses.
These sociological problems, I believe, are in fact contradicted by the laws of physics. To construct a ship of that size would require the same, or more, energy and resources as that required to construct a fusion-powered ship which can travel at a velocity fast enough to make generation ships unnecessary. Even at a mere 0.1 lightspeed, given the distance between stars, it would only take half a lifetime to get from one star to the next (once you are in a star system you can replenish everything you need because you have fusion, regardless of whether there are habitable planets there or not).
What this means, psychologically, is that a species would have to be psychologically stupid to construct a true generation ship which can only reach a velocity which means travelling from one star to the next takes longer than a single lifetime.
The sociological issues are relevant, though, even on a ship which does take 10, 20, 40 years to get from one star to another. Children would obviously be born on the way. Even with a fusion torch, resources would be very valuable.
Part of my point here is the logic of technology, or technological advancement. Put simply, you cannot achieve interstellar travel of any kind without developing the technology which makes generation ships unnecessary. Sleeper ships likewise.
It's all about velocity of travel, in the end.
That's not to say one can't write cool stories about generation ships and sleeper ships. I love the concept and have done some myself.
What a really fun essay! Exactly the reason why Substack is great in some areas. Have you considered the fact that a portion of the engineering of a generation ship would be devoted to harvesting gravity from the centrifugal force, particularly in relation to the water cycle? AI pointed out that the process would likely be net negative for energy, but I think if it ran from existing systems to maintain human habitability, then the story changes somewhat, because then the question is less one of thermodynamic law and more one of reclaiming energy already expended in a closed loop. A lot of agricultural reservoirs already have pumped hydro feeding off the main reservoir, and hey they had indoor rain in the Saturn rocket site, didn't they?
Also, a lot of mirrors- both for lighting energy purposes and illusion of space psychology.
Computer says no for telluric energy:(
I will look forward to further essays. I imagine your Substack will grow quite quickly. Plenty of engineering geeks and hobbyists lurking on Substack. Somebody should probably start one on Meccano.
Of the multiple reasons why interstellar travel is impossible the best I've heard recently is that we simply do not know how to manufacture the standard O'Neill cylinder. No known material has the tensile strength not to fail under its own weight.
If we did manage to solve this and the other obvious problems, I suspect travel would revolve around planning a route from asteroid to asteroid and using each one as a manufacturing base. If the Oort cloud surrounds the sun for up to three light years and other stars have similar clouds then the problem gets easier. But if the number of generations a generation ship needs is massively increased by mining and repair work along the way then it might seem like an insoluble problem for anyone who might build a generation ship.
I can see a wealthy person wanting to invest in something for their grandchildren or great grandchildren. But if that gets expanded out to 10 or more generations nobody will much care about their descendants at that distance.
Hi Vincent! Just stumbled on your publication here. Are you planning on serializing your novel, or publishing it elsewhere?
If you'd like to see how I approached these ideas, I'm publishing a generation ship novel on substack one scene at a time this year. The tightness of the ecosystem and the effect this would have on their mentality is something I tried to capture. As well as the slow but inevitable effects of entropy. Everything is shiny when first boarding, but after decades, the place loses its luster!
Hi Randy, I'll check it out! I am not going to serialize my book, I will publish it as an ebook. The generation ship is more of a past setting, but I keep thinking about these details and how it would affect the society aboard.
My solution, in the story I might someday get around to finishing, is to go big. You need a big enough crew to have a viable and healthy population and big enough to run the ship, but not too big. The ship itself though, is enormous. Way, way bigger than an ordinary ship. Redundancy upon redundancy, and stocked with enough to keep a population alive during the journey to and terraforming of a new planet. 25 generations.
Going big makes sense, but renders the ship an even bigger investment for Earth. Let me know should you ever publish your story!
As you describe such a vessel will need to have extremely efficient recycling methods. Developing this capability will require a lot time. Thus, a generational ship will be former space habitat that has been outfitted with propulsive capability. Before a journey of centuries can be contemplated, a proven track record of centuries of continuous operation of orbital space habitats will need to have been achieved. The people living in the habitat will see it as their home. They have all they need here in orbit around the sun, why should they leave?
The *reason* to go to another star is for the *planets* there. What generational ships get wrong is they assume the people on the ship are like us, planet dwellers. But they are not. They are a completely different (cultural) species from us. You could build a clone of one of their habitats, outfit it with engines, put Earth people on board and set off for another system. The people who left would be Earth people, interested in finding new planet on which to live, but the people who arrive centuries later, no longer will be planet dwellers and have no interest in the planets at their destination.
I could be completely hallucinating, but I seen to recall a novel (a movement?) when I was young that suggested the Earth itself was a generation ship and that all care should be taken at all times to keep it going. Seems sort of Ursula LeGuin meets the beginnings of climate doomers.
Stewart Brand’s Operating Manual for Spaceship Earth, most likely. Drew heavily from Buckminster Fuller.
That sounds exactly right. I'll have to revisit that! Thank you!
Gerald O'Neill looked at space colonies. In his case the colonies were in the solar system with easy replenishment. After a hundred years of experience, making a closed ecosystem might be more feasible. Energy would seem to be the limit. In the solar system sunlight is readily available. For a generation ship you would need either Uranium, Thorium (fission) or Deuterium (Fusion). Those are be nature nor recyclable. Perhaps faster but smaller ships could be used to resupply the ship.
You would have to bring an inventory of fuel with you as well as raw materials. It is entirely possible than multigenerational interstellar travel is technically impossible. But even if it is possible it is precluded by cultural evolution as I noted in my other reply.
Generations by Noam Josephides:
Does a decent job, and specifically covers what the people of the different generations would be like - a good read in my opinion
Also Apple TV Silo while not a generation ship has a lot of similarities and has a patch and recycling vibe
Thanks David, I will give it a try!
One aspect to consider is population. You would need to keep a stable population, something that I suspect is not possible. Stories along these lines often have an element where reproduction is controlled to stop runaway population growth. But I've not seen anything that considers population decline. What if living in such circumstances pushes people away from wanting to have children? That people just stop reproducing and the population declines beyond the ability to support all the required work.
The conclusion to this is, outside of an unlivable earth this world not be worth it.
Good article
You wouldn't want to build a generation ship, until you'd built a space habitat and run it for the same length of time, with careful attention to imports, and know how little you needed.
And you can practice building your habitat, a kilometre underground, first. Build a habitat down there, safe from all the giant Roland Emmerich disasters except for loss of the entire planet. 80% of the species-protection for 20% of the cost.
If we can run one of those for a century or so, then use that expertise to build a long-term stable habitat, we might be able to build one that goes somewhere.
I am skipping over the small matters of propulsion and available energy. You aren't going anywhere interstellar until the price of energy drops below a penny a megawatt-hour, so developing all that may take the time for the experiments above.
The underground habitat as a starting option a good idea, but good luck getting hundreds of people to volunteer to live in a cave for the rest of their lives!
"I'm sorry, sir, but we need you to take the laxatives for 3 days straight before you get your 1-year term in the Redoubt. The Import/Export rules expressly forbid you bringing in biological material that will be added to the balance. Also, we need your weight down by 736 grams to exactly match the guy who is rotating out".
The question is would the sort of people who would volunteer to do that be the sort of people you'd want to do it?
Hang on, maybe four-year terms: and you emerge with a degree. Or a four-year tech degree in maintenance of life systems. Throw in an artist's colony, free accommodation as long as you're part of the experiment. And of course, a care-home and hospice, to simulate the Final Donations of the population to the gardens.
Generation ship is a vague term. One hundred years (everyone that started the journey would die before the destination is reached) might be possible. One thousand years might not.
Yeah, and a hundred years is a hell of a long time already for a pressurized structure with tha capacity of a medium sized city, fully isolated in deep space.
In addition to what you wrote, which is entertaining, there is an additional dimension beyond the engineering/materials issue and the social issues. That issue is evolution by natural selection. Putting a group of Homo Sapiens, with sufficient genetic diversity, onto a generation ship on a long one way journey is a perfect mechanism to achieve what speciation does on earth: Isolated populations of a species naturally, through selection pressures, genetically drift from the origin species, to the point where they eventually become separate species with their own future evolutionary paths. Think of Darwin’s finches on the Galápagos Islands, or the cichlid fishes of Lake Victoria.
Indeed, the history of Homo Sapiens itself illustrates this. Homo Sapiens has been around for about 200,000 years, but modern Homo Sapiens, us, are a more recent development, appearing about 100,000 years ago. In that time, Homo Sapiens coexisted with at least three other Hominids, Neanderthals and Denisovians being two of them. Sapiens developed in isolation from those other Hominids, arrived into their territories, and after some period of partial interbreeding, basically outcompeted the other Hominids by about 40,000 years ago, such that Sapiens is the only remaining one on the planet.
Evolution has not stopped.
Put a group of Homo Sapiens into a deliberately isolated population such as a generation ship, and they will inevitably become a new species of Homo. Indeed, depending on the length of the journey, the beings may be a new species by the time they arrive.
This is true even if they arrive on a planet that is Earth like to extreme degree. The speciation/adaptation will be even faster the farther away from Earth conditions the new planet is.
This progression is also true for every other living thing on board the ship: Plants, animals, and bacteria brought to enable growing food and providing other materials. Undiscovered viruses, bacteria, and parasites carried onboard by all species will also undergo their own mutation/adaptation cycle, with unknown future effects. All of those are going to drift and mutate as well, both on the generational ships and once they arrive. And there is basically no amount of engineering that can prevent or direct that. In fact, it would be self-defeating to even try. Life MUST adapt to its environment or it goes extinct if it can’t.
And we know what mutates and adapts faster than the genetics of Homo Sapiens: language. We still have some undeciphered written languages that are only a few thousand years old. We have evidence of many hundreds or thousands of “lost” languages. Even more recent, most non-specialist readers of modern English could not easily read old English (or even Middle English), and if they could, it is equally likely that they could not correctly pronounce the words they read if they spoke them. And the same works the other way: if you brought a speaker/writer of Old English to the modern United States, I suspect they would be completely bewildered by what they hear and read.
A generation ship has the equal risk of its inhabitants and Earthlings being relatively quickly unable to mutually understand communications from each other, as both languages are evolving in their own ways.
Given the extreme focus on stasis that the generation ship must engage in, as the article points out in detail, I suspect the likely scenario is that Earth languages will continue to evolve, while the generation ship’s language remains more or less static relative to the language state when it left.
This situation is doubly reinforced due to the generation ship’s need to rely on the state of the languages written in all of the materials on board the ship.
Have you heard of a technology called the Fusion Torch? It can recycle anything into its constituent elements. Concept invented late 1960s. Obviously the powers that shouldn't be have never allowed it to happen because it would render the commodities market obsolete, and control over that (enforced scarcity) is one of the primary mechanisms of social control over the masses.
These sociological problems, I believe, are in fact contradicted by the laws of physics. To construct a ship of that size would require the same, or more, energy and resources as that required to construct a fusion-powered ship which can travel at a velocity fast enough to make generation ships unnecessary. Even at a mere 0.1 lightspeed, given the distance between stars, it would only take half a lifetime to get from one star to the next (once you are in a star system you can replenish everything you need because you have fusion, regardless of whether there are habitable planets there or not).
What this means, psychologically, is that a species would have to be psychologically stupid to construct a true generation ship which can only reach a velocity which means travelling from one star to the next takes longer than a single lifetime.
The sociological issues are relevant, though, even on a ship which does take 10, 20, 40 years to get from one star to another. Children would obviously be born on the way. Even with a fusion torch, resources would be very valuable.
Part of my point here is the logic of technology, or technological advancement. Put simply, you cannot achieve interstellar travel of any kind without developing the technology which makes generation ships unnecessary. Sleeper ships likewise.
It's all about velocity of travel, in the end.
That's not to say one can't write cool stories about generation ships and sleeper ships. I love the concept and have done some myself.
https://inadifferentplace.substack.com/p/dystopians-and-interstellar-travel?r=2s9hod
I'm looking forward to reading your novel - these are exactly the interesting questions good sci-fi explores
Thanks! I'll be sharing news on the release here, but it's going to take a little while until that happens...
What a really fun essay! Exactly the reason why Substack is great in some areas. Have you considered the fact that a portion of the engineering of a generation ship would be devoted to harvesting gravity from the centrifugal force, particularly in relation to the water cycle? AI pointed out that the process would likely be net negative for energy, but I think if it ran from existing systems to maintain human habitability, then the story changes somewhat, because then the question is less one of thermodynamic law and more one of reclaiming energy already expended in a closed loop. A lot of agricultural reservoirs already have pumped hydro feeding off the main reservoir, and hey they had indoor rain in the Saturn rocket site, didn't they?
Also, a lot of mirrors- both for lighting energy purposes and illusion of space psychology.
Computer says no for telluric energy:(
I will look forward to further essays. I imagine your Substack will grow quite quickly. Plenty of engineering geeks and hobbyists lurking on Substack. Somebody should probably start one on Meccano.
Super read. Fiction, whether it’s books or films, has romanticised the concept of generation ships for sure. Reality is a lot grittier.
Of the multiple reasons why interstellar travel is impossible the best I've heard recently is that we simply do not know how to manufacture the standard O'Neill cylinder. No known material has the tensile strength not to fail under its own weight.
If we did manage to solve this and the other obvious problems, I suspect travel would revolve around planning a route from asteroid to asteroid and using each one as a manufacturing base. If the Oort cloud surrounds the sun for up to three light years and other stars have similar clouds then the problem gets easier. But if the number of generations a generation ship needs is massively increased by mining and repair work along the way then it might seem like an insoluble problem for anyone who might build a generation ship.
I can see a wealthy person wanting to invest in something for their grandchildren or great grandchildren. But if that gets expanded out to 10 or more generations nobody will much care about their descendants at that distance.