What's the Minimum Number of People for a Generational Ship to Proxima Centauri?
universetoday.com
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This is the dilemma that should make us really consider and possibly wait for the right technology. Otherwise it is quite possible to arrive to destination and find it populated for millennia.
That’s 1952. Probably it was already a trope by then...
... or not. It's been at least 15 years since I read it.
If one is thinking from a species planning perspective, the question is an interplay between the (a) development of propulsion technology and (b) propensity for our species to annihilate itself. Given (a) and (b) are intrinsically related, there is likely an elegant solution.
Parker Solar Probe his 200 km/s in orbit around the sun.
From my perspective, it makes more sense to risk obsoleting previous missions and send ships as soon as it’s possible to do so because it’s a far better outcome than waiting for tech that never came and never sending a mission at all.
The women you send there would still have the problem of potentially arriving to their destination to find it has been populated by humans for millennia. (If they arrived at all. Interstellar space is a dangerous place.)
It would be anticlimactic in the extreme to arrive to a destination to find a thriving civilization thousands of years ahead of you in terms of technical know how.
Right. It doesn't seem to me that humans can live outside of Earth's safety for any significant duration of time at all. The Sun is very explosive.
That would be extremely exciting! IMO even more exciting than finding a desolate planet. Discovering an entire unknown civilization is anti climatic? No way, it would be like discovering Atlantis! So what if they’re more advanced? We were capable and curious/brave enough to even make the trip! Keeping score would be pointless but the fact would remain that we made first contact with them, on their turf, even though they were more advanced.
(I chose wormholes specifically because it makes it more believable that you were not contacted or picked up and pulled along by the faster technology.)
A mission like you suggest would require us to create precisely calibrated wormholes. Which is quite a step beyond DISCOVERING a wormhole.
Anyways, lots of ways to skin a cat. Making wormholes may be one way, but faster space ships, or controlling gravity, or teleportation, or some other fantastical exploit we haven’t even begun to imagine may be another.
I have to imagine being born on a ship and being told that your grandparents signed you up to live and die on it for a science experiment would potentially cause a psychological aversion to wanting to follow the rules set down a generation before regarding sex and procreation.
Artificial wombs are already a thing: https://www.cbsnews.com/news/artificial-womb-baby-lamb-raise...
Now granted, this technology up there is only intended for premature births, i.e. the fetus continues to grow in the artificial womb after birth. But with the technology for IVF covering the first phase of gestation, and this artificial womb covering the last phase, the gap between both appears to be shrinking. IANAD (I'm not a doctor) though, so take this with a grain of salt.
As we improve medicine and merge with AI, we should expect other changes to be possible, not just brain interface changes, but also body changes. Essentially we are still a version 1.0 and the iterations to new versions haven't even started yet... but these should be well underway in the timeframe of starting voyages to other stars.
Even for Mars, much closer obviously, we should think about whether it's easier to change body types in the medium term than it would be to terraform Mars to a desirable level.
This could be called bioforming[0][1] and here's an abstract for a paper that suggests modifying humans, alongside modifying Mars, to speed colonization.[2]
[0] http://memory-alpha.wikia.com/wiki/Bioforming
[1] http://terraforming.wikia.com/wiki/Bioforming
[2] https://www.researchgate.net/publication/289486325_Bioformin...
But that runs into the organizational problem that a society that's lived in space for two or three generations may not want to deal with this messy, disease-ridden, gravity-encumbering planet business again.
1. be sterile, meaning that this is not a concern. (The only germs that settlers will run into are those they brought with themselves on the ship.)
2. contain alien germs, in which case no humans would have antibodies for them regardless of origin or travel speed.
But if you're going to do that, there are useful asteroids waaay closer than the next star system over.
Interstellar colonization makes some degree of sense, but not until we're pretty far along exploiting the local system. It's not something even our great-grandchildren are actually going to do while there's so many resources here.
But, eventually, if humanity and its descendants keep growing, eventually it makes sense. And rather than cobbling together something that can just barely make it and then do nothing, by then they'll have the infrastructure to make many ships, and give them useful things that will actually be helpful at the other end. And they may even be able to build "bridges"; if space really is full of ice planets we can't see, those make fantastic bases for launching and deceleration lasers, and if you can use those, the economics suddenly start looking a lot more practical.
And I'd point out that barring a lot of very enormous coincidences, other planets aren't going to be "disease-ridden". If anything has to worry about being "disease-ridden", it's the ship they're on, not the almost-certainly sterile matter on the other end.
Kim Stanley Robinson's novel Aurora talks about a bunch of this. Robinson mentioned that he was tired of talk about generation ships avoiding the biological, social and ethical factors and just focusing on the physics and technology, when those are probably the easiest bits. Highly recommended.
I agree. That's why I'm not moving to the suburbs.
Suffice it to say the technology is not yet up to the task.
People have endured far worse conditions for generations. Humans are probably the best choice in fact, for creating and propagating small communities for generations.
A child on a generation ship would have no such choice: you're going to live and die on that ship whether you like it or not. And that's at the very minimum. It's pretty likely that, to be sustainable, a generation ship would dictate your profession, marriage partner and number of children as well, with no exit rights. Forcing that life on someone with no say in the matter is pretty unethical.
Of course I exaggerate. But I see this as a First World Ethical Problem.
Of course. But you hopefully agree that civilization has progressed since then. I do not find it ethical to force people backwards in time compared to the contemporary environment they could have.
If I forcibly teleported you back to the kind of agricultural, tribal society that existed for most of history, where leaving would be death (either by punishment or just lack of protection from the dangerous outside world), and the tribe's elders dictated most of your life decisions, would you consider that ethical? What about if I pledged to do it to your unborn children? That's what we're talking about with generation ships.
We're currently condemning our children to live in a world with melted ice caps and extinct ecosystem. Perhaps these lucky few will count their blessings.
Children getting 6 hours of sleep because Facebook puts them on the spot 24 hours a day is also a tragedy.
That seems pretty optimistic. I think the reality would be exactly the opposite: resources are extremely limited in space and there is much less room for error, which pretty much demands an authoritarian society where individual choice has to be severely curtailed, and the environment would be constrained by the same lack of resources.
Of course, the level of technology in the ship would determine just how bad it would have to be, but I don't see any future within the next thousand years or so where you could have an environment on a generation ship anything like what we have on Earth.
2. You will never see an interstellar voyage that is longer than today’s lifespans. Because otherwise there would be time to build and launch a faster ship using new technologies which gets there sooner.
There's also no discussion of life extension, which seems more near term than interstellar starcraft.
Anyway, we will probably have good data on the optimal size of asteroid colonies long before interstellar colonization is a live issue.
So long as we’re comparing unknown unknowns, we might as well throw fusion and GAI in there.
Hard times create strong men. Strong men create good times. Good times create weak men. Weak men create hard time.
This social dynamics would not go well on a generational ship.
Take that with a grain of salt, memory and amateur research are finicky.
https://arxiv.org/ftp/arxiv/papers/1708/1708.08649.pdf
I had to go to the linked study to get the answer. If an article posits a question in the title...it should answer it in the body. Hopefully in the first paragraph.
With 32 the chances of success drop to 0%
I thought the number would be 10-50 times larger.
The actual number in the paper is 98, and even that probably wouldn't be a very healthy population of humans. Around 600, with significant initial diversity, is the number I've seen tossed around as the minimum number for a genetically healthy population.
Even if we had the propulsion, which we don’t, we’d still be screwed.