All the more reason to use it in place, rather than waste so much time and energy moving it more than needed.
Build a self-mobile, mostly self-sustaining habitat (not a generation ship! No, of course not, not that, wink wink!). Scoop up a comet, use that as resources as you leisurely make your way to the next comet outwards. Design the habitat (not ship! Habitat!) so that it can build new habitats en route, which then spin off as new communities. Every few generations, when a new habitat is available, there’s a massive act of practical democracy, where everyone decides which which shiphabitat they want to live on.
I think I am agreeing? “Instead of” creates a false dichotomy. Take as best care of this planet as we can and diversify the investment … yeah humanity may existentially fuck this planet up, or a planet klller asteroid may slip by somehow despite best efforts. Unknown unknown risks.
To the original OP - cultural norms adapt to societal needs. A generation ship is a strange land and those there would grok it.
I think we discussed this a few months ago. Moving from Oort cloud object to Oort cloud object would require a lot of delta vee, and therefore a lot of fuel. This strategy only works if you can mine the Oort cloud for fusable elements such as helium, deuterium or something else; otherwise you will run out of fuel and eventually freeze to death. The Oort cloud is a pretty inhospitable place, and the objects are very far apart.
The other problem is finding the rocks in the first place. Forget about seeing them by reflected light. The Sun is a quarter lightyear or more away. Also forget about finding them by IR, since their temperature is something like 30 kelvins. Possibly a very powerful radar could locate them, but since the nearest one may be as far away as Neptune is from Earth, I wouldn’t be very optimistic about that.
Not really. Way out there, orbital speeds are nearly zero. It’s not quite the physics-textbook ideal of “no forces”, but it’s very, very close. You can use a very small amount of delta-V to meet up with a different object, if you’re patient.
The key word there is ‘patient’. I don’t want to travel a quarter of a lightyear (or any non-trivial fraction of a light year) on a few km/s of Delta-V.
If we are going to travel around at the kinds of speeds we send probes out now, it would be totally infeasible to mine the Oort cloud. Voyager 1 is going to take 30,000 years just to cross it the short way, and until New Horizons came along it was the fastest thing we ever launched.
The whole mining the Oort cloud thing presupposes that we are going to run out of things to mine in the inner solar system. That prospect is so incredibly far in the future that even if mankind survives that long, we wouldn’t recognize them. We have not even the remotest idea of what a civilization with the capability to strip all the resources from moons and planets will want, be capable of, or willing to do.
I think we’ll find quite a few people who are contrarian enough to do just that, maybe even just to spite people who say it’s impractical or irrational. We already have people who do things like that. I suspect most of these groups would look like some kind of cult to us, if we were able to meet them.
The people who boarded wooden ships in 1600 to go set up colonies in America probably looked just as crazy. In fact, lots of them were loony religious cult-type people. I think it will take more than a few thousand years to evolve past that.
Years ago I devised a list of different interstellar strategies, and this one was on that list.
I called this strategy seed ships; you can send a lot of biological material to another system in the form of seeds, including humans, but you need to include autonomous devices that can take the place of parents and teachers on arrival. Not easy.
I assumed that spacecraft would never travel much faster than 0.1c, because anything else requires far too much energy. But this assumption may one day be unfounded.
The full list is as follows;
1/ Methuselah ships. The problem with interstellar travel is it takes too long. If we can extend human lifetimes by an arbitrary amount then humans could get to the stars in a single lifetime. This strategy requires advances in technology not yet available, but that is true of all of them.
2/ Sleeper ships. Freeze people (or otherwise suspend their metabolism) and wake them up on arrival. Same objection as #1.
3/ Generation ships. We are discussing these at the moment. To make a generation ship work well, you need a lot more mass, and this implies that the acceleration and final cruising speed will be a lot slower. If you do your sums right, the generation ship can transport a lot of people to the destination, but it takes a lot longer.
4 / Seed Ships; I assumed that biological seeds could be transported much more cheaply than entire humans or entire animals, so you could send a lot more ships. But cultivating the seeds at the destination requires a lot of not-invented-yet tech, and competent robots.
5/ Data only ships - this means just sending robots, AIs and comprehensive databases to the stars, and forget about sending humans until the robots are ready to receive them. Trouble is, the robots might not want to be bothered with humans, and just defer their arrival indefinitely.
Hmm. Perhaps there are entire civilisations travelling at a tiny fraction of c between the Oort clouds of nearby stars. We probably won’t be seeing them arriving at Earth in the foreseeable future.
We may well be agreeing. But there do seem to be some people who talk about space habitats/travel to other planets as if it’s some sort of solution to environmental problems here. A planet-splitting meteor could be another matter – but the chances that we’ll succeed in screwing up this planet, not only so badly that we can’t survive on it, but so badly that it will be less hospitable to us than even next-door Mars, are poor. We’d have to do such a thorough job that never mind not only the cockroaches and algae, but even the tardigrades couldn’t make it.
They were heading for a place where they expected – with good reason – to be able to breathe the air, drink the water, eat the wildlife, find fuel and building material, and grow crops. Not to mention that they were expecting to be confined on the ship at most for a matter of months, and to be able to send back for more supplies and to exchange people. Some of them were indeed religious cults; and there may actually be enough people willing to voluntarily staff generation ships; but I think the difference in the degree of looniness required is nevertheless considerable.
Maybe it would be somewhat less so for literal looniness, as in people willing to settle Earth’s Moon – they might be expecting to be able to get back if they couldn’t stand it. And probably less so if it is a matter of such habitats getting gradually further out from Earth after people have figured out how to live on them. If we can successfully raise children in such habitats, then the children might not need to be loony at all to want to keep it up. But I don’t think it’ll be trivial to get past that “if”.
And I also don’t think we’ll ever be able to pull off space travel unless we can learn to stop thinking about it like sailing across the Atlantic, or even like taking a canoe to the next island somewhere way out of sight in the Pacific when all you’ve got is canoes. It’s not only a whole different thing. It’s a whole different order of thing – to more than one exponent.
In between stars, nothing is coming into the ship. A century later, future generations will have exactly the resources available on board (less whatever was used up.)
So you can’t afford to just let a human body float away—or even to burn it. Everything must be recycled, every byproduct captured, etc to create an entirely closed loop. If some pipe leaks a single droplet of water every couple days, everyone on board will eventually die. The same goes for basically any resource. If a loop goes unclosed, the whole ship fails.
Shooting resources of any kind into space would be an act of sabotage.
Excellent idea. Properly planned, the initial garden can be one that is used to help supply oxygen to the ship - so Grandpa starts giving back pretty much as soon as he kicks off. By the time any of his molecules go into the hydroponic food supply, they’ll bear no resemblance to anything squeamish-making.
Lois McMaster Bujold’s book, Ethan of Athos, discusses something quite similar. It’s a space station, not a generation ship, but all mass is accounted for. Human remains are sent to feed plants. Which, of course, ultimately go into the systems that feed food production…
The point isn’t whether it’s better to test your generation habitat in Florida or in Anarctica or in earth orbit or someewhere else. The point is that basically nothing is being invested in it.
Elon Musk builds big rockets that could go to Mars. Fair enough; soaking up taxpayer funds for nebulous space programs is a time-tested way of getting rich. We’ve built Mars rockets before; there’s nothing particularly novel about that. Musk will send something to Mars (probably another of his cars) and that’s fine.
My issue is he keeps babbling about starting a Mars colony to “spread the light of human consciousness or whatever”, but this obviously does have a huge engineering requirement that nobody’s tackled before - keeping a crew alive and healthy for 2 years, with minimal (if any) prospects for resupply or rescue.
That pesky little “habitation” part of Mars colonization is the real bottleneck, and Musk hasn’t even started to address it. Like he hasn’t even done the basic thing of having people live in a sealed luxury hotel for 4 weeks in Texas and trumpeting it as a publicity stunt.
Nobody’s creating a Mars colony because nobody wants to do even the basic work required to make Mars habitable. There is no argument against this uncontroversial fact except “they thought landing on the moon was impossible”, which is no kind of argument at all.
I don’t think there’s any reason for anyone onboard to be squeamish about it - the launch generation would have to sign up to it; for subsequent generations it would be part of the only normality they had ever known.
I suppose you might get people spontaneously dissenting to this (or indeed any other matter in the closed-system life and society on board - but that’s a different matter more related to policing)
A couple of months ago, CBS Sunday Morning ran a story about composting as a way of disposing of human bodies. They visited a Seattle facility already set up for this. So perhaps something similar would work on a generation ship.
This is not a trivial problem; it’s a deal-killing one. So long as we don’t know how to make an environment that will support humans long-term without resupply from Earth, we can’t do generation ships, we can’t do space colonies, we can’t colonize other planets, we can’t even manage human-staffed research stations that are further out than our ability to supply them easily reaches.
And we have, as it stands, no idea whatsoever how to do that.
That of course doesn’t mean that we can’t learn how. But anyone proposing any of those things who isn’t simultaneously experimenting, here on Earth and/or in orbit within reachable short-term rescue distance, is either a fool or a scam artist (or both). It isn’t something that can be figured out rapidly at the last minute; and it isn’t solely an engineering issue, in any of our standard senses of engineering, though engineering will certainly be involved. It requires a degree of ecological knowledge that we’re only beginning to understand the breadth and complications of.
I would say that it is an engineering issue, specifically, ecological engineering. But ecological engineering is a field that’s still in its infancy, and still requires a great deal of experimentation (far more than a mature engineering discipline like structural engineering).
But yes, the overall point stands, that we need to be doing that experimenting to make ecological engineering a mature discipline before we can even start proposing any sort of long-term off-Earth habitat.
Fair enough. But I think ecological engineering is going to turn out to be a lot more complicated than structural engineering. We’re still very much in the stage of ‘the more you know, the more you realize that you don’t know’.
But we very much do need to work on it; because, while still in that state of huge ignorance, it turns out we’ve been ecologically engineering the planet we’re living on. Lately, that hasn’t been working out real well.
If this were the part of getting people off the planet that were being hyped up and that money were being poured into, I’d be a lot happier. At least, as long as the experimentation was being done with a great deal of caution.