Exactly. A generation ship doesn’t need to carry a viable genepool except as stored DNA. The only advantage to sending living humans at all would be to have someone to raise the kids at the destination, and by the time we will have the technology to build generation ships we will probably have robots capable of child-rearing.
That’s not a generation ship, in my classification system (which Isaac Arthur also uses); it is a Methuselah ship, full of long-lived individuals who don’t need to breed at all. If the inhabitants of a Methuselah ship do breed, they will increase in number geometrically, unless they agree to die voluntarily to maintain a stable population.
Or perhaps the older Methuselahs could go into suspended animation for the rest of the trip.
Yeah, I think it’s worth considering that what this generation ship would be, is pretty much a prison, and most people don’t want to go to prison, especially forever. Even if you were to try to institute some system of control analogous to prison guards vs inmates (or whatever, really), that only has to break down once in the tens of thousands of years voyage, and it will stay broken.
Whatever high and altruistic motives the initial crew might have when they set out, I don’t think it’s likely those could be reliably and consistently instilled upon future generations being born and raised in space prison.
Interestingly, the generation ship in The Expanse was originally built and crewed by Mormons, who might have been able to maintain a consistent and stable culture for a thousand years. Perhaps any or all generation ships will be the product of stable cultures, cults, or autocratic societies with severe penalties for non-conformists.
Don’t a fair few Mormon kids rebel pretty hard?
Humans are too complex. Termites could handle interstellar travel better than us.
I’m not sure people would chose to bring children into that environment. We’re already have people today deciding to stay childless because they don’t want to bring a child into this world. I would imagine there would be a similar sentiment on a generation ship. The initial crew would probably have children since they would likely be most motivated to fulfill the mission, but I don’t think future generations would do so. Someone who has lived their whole life in a generation ship might not want to subject their child to that experience.
I suppose there is the argument that it would be all they have ever known, therefore they would have no reason to expect anything more, but I’m not sure how that would work out in reality.
Can’t think of the names; but I’m about 99% sure that at least one SF author has written a version of that. I’m sure I’ve read one, but my memory of it is too blurry to say any more than that.
Several stories of this kind have been written; one I particularly remember is the first issue of the Guardians of the Galaxy comic book, which has the character ‘Vance Astro’ (terrible name) arrive at Alpha Centauri to find that entire fleets of colony ships have arrived before he did.
There is a concept known as the Wait Equation that suggests that no-one will build the first, slowest ships, because they will almost certainly be overtaken by later, faster ships.
https://www.centauri-dreams.org/2006/11/24/barnards-star-and-the-wait-equation/
On the other hand there may very well be very strict limits on the fastest possible craft, given the vast amount of energy required to reach faster speeds, and the problems of interactions with the interstellar medium. So once you can accelerate a ship to a certain speed, there would be no realistic prospect of ever travelling faster.
Why, any more so than living in a small town you never leave from, or an isolated island unaware that other islands exist, or as an isolated tribe of hunter gatherers deep in a forest?
Being a prison implies a deprivation of freedoms you otherwise would have. Those raised on the ship only know the myths of planet life, even the first inhabitants may never have been on one, may have always lived in space structures, maybe more constrained than the ship one.
It’s a small self contained world. Maybe all worlds are prisons to some?
Humans living hard subsistence lives have wanted families. No reason to presume misery but even if so, to the degree the society allowed a choice about procreation, and it might not be a choice made by individuals, enough would still choose so. And if fewer than replacement? More space and resources for the next generation, so less misery, so more deciding to have children…
I’ve read quite a few stories in which the space travellers think that it’s the planetbound who are imprisoned.
There are a whole lot of problems involved with making any generation ship work, and some of them may well be insurmountable; but I doubt this is the insurmountable one.
I like that one!
If anything else breaks, you can work around that with redundancy. If society breaks on a generation ship, there’s not really a spare.
In 100,000 years, is it likely to break just once? I think so. Breakdown of various civilisations here on Earth didn’t end the human race because there sort of was always a spare - some other up-and-coming culture off to one side, for whom the demise of the other culture was an advatage (or by whose hand the other culture was overrun). It worked here because the environment was sufficiently large to contain and somewhat isolate separate cultures - so they could collapse, be usurped or destroy themselves one at a time.
Which suggests the solution. Multiple isolated ships. Just bring (more) money.
I don’t disagree with that. I just doubt that feeling imprisioned would have to be a breaking point; at least, if the first generation were selected with that in mind. Later generations would be used to it.
In 100,000 years society would almost certainly change drastically, multiple times. Some of those changes would be in response to the previous culture breaking. Whether the group on the ship would survive all of those breaks sufficiently to create a more functional successor culture is of course a question; and it does seem to me to be a major problem. And it’s one of the things that seems to me to be wrong with some generation ship fictional stories and most plans for them, which often seem to assume a recognizable single culture being maintained for that long or even longer.
If they stay isolated, that won’t help. The reason it helps in actual cultures on Earth is because isolation isn’t complete, and the unbroken cultures can eventually fill in the space, as well as support one another.
You’d need some way to set up reasonably easy occasional travel between/among the ships, and conversation among them. Which would also carry a risk of a particular type of break spreading among them, of course.
Somebody, or several somebodys, has probably already written that story, too; though I haven’t read an example.
– of course, on Earth, a broken society may damage the local ecology, but (at least until quite recently) generally can’t damage it beyond its possibility of repair. Destroying a generation ship so as to make it permanently uninhabitable would be a lot easier.
Emphasis in @Mangetout is on the “or by whose hand.”
ISTM that in human history the most typical way for societies to end has been by the hand of others: tribes of humans destroying each other at various scales. Sure on occasion a group has been small enough and on a narrow enough resource base that climate changes or such destroy them, but not typically.
Humans seem to function best socially on a tribe level. The size of a kibbutz in Israel comes to mind where the ideals of “communism” actually worked. But the ecosystem works better much larger and interconnected. Buffered.
Maybe the ship consists of many separate Kibbutz sized units that don’t even know the others exist, or minimally have no to little contact with them (special deal interchanges allowed maybe), except for one unit that has responsibility for monitoring and coordinating the others? That overseeing unit could quarantine a unit that is becoming toxic in some way (their contribution to general good covered by redundancies) before they pose a threat to the greater good, even allowing that individual tribe to collapse and repopulating it afterwards?
I think there might very quickly be problems arising from giving a small and isolated elite the power of life and death over groups of ignorant tribespeople.
I was thinking about a design that is a “ship of ships”. Several complete ships, each able to carry out the mission alone, for redundancy, but still linked in some manner, so that they can exchange people and resources as needed, in case of non-catastrophic accidents, or for the reasons discussed below.
Each ship would have a captain, and one captain would have over-all control of the ship of ships, with that role switching between all the captains on some kind of schedule.
Each ship could organize itself as it sees fit, and can use information from the others in deciding what to try. Perhaps we could also establish a tradition of some percentage of the populations of each ship emigrating to a different ship every 10 years or so. It gives disgruntled people a chance to find a new home that’s better suited to them, while also ensuring just enough commonality of culture (and genetics) between ships so that they don’t eventually become completely incompatible with each other.
Coming up with a physical design of the ship of ships would be the tricky part. You’d want each ship to be self-contained enough so that a disaster on a neighboring ship wouldn’t affect the other ships. Also, you’d want some controls against one ship invading another. But at the same time, you’d want the ability to invade one ship, in case that ship went crazy for some reason. Maybe have a control system that requires X number of ships to agree to unlocking the target ship, or something.
The politics of such an arrangement would provide all sorts of good stories for an aspiring author…Too bad I suck at that.
Sure, but that’s a bit like the way predators always pick off the weak and sickly members of the herd. If you take away the predators, that doesn’t end weakness and sickness.
this is why I foresee a very draconian, supressive and autoritarian regime on board … (think: Captain Bligh on the Bounty) … there is no place for opposition, second-guessing and parallel agendas.
agreed! just as a data point: 100.000 years, is twice the temporal “distance” from us to neanderthal people !!! - so that is quite something - nearly unfathomable
way too democratic (dare I say “woke”?) … e.g. lots of people wanting to leave ship Nicaragua and enter ship USA … you get my drift …maybe a regime of “social-credits” like in today’s china … do more than expected and get brownie points, do less than expected of you and you get the stick.
I’d really draw the analogy to a historic war-ship etc… a highly vertical power structure, “this is your place, this is your job, and no - nobody asks you if you really feel like storming up hamburger-hill today or not”.
A generation - ship is not a place to cultivate your individualism and freedoms …you are a keg in a system … and the system will come down on you if you don’t do your part.