# What to do with with dead bodies on Generation Ships **URL:** \ **Category:** In My Humble Opinion\ **Created:** [June 14, 2023, 5:58pm UTC](https://boards.straightdope.com/t/what-to-do-with-with-dead-bodies-on-generation-ships/985514 "2023-06-14T17:58:10Z")\ **Posts on this page:** 20\ **Page:** 11
**Author:** ![Horatius](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/horatius/32/3572_2.png) [@Horatius](https://boards.straightdope.com/u/Horatius)\ **Post date:** [August 15, 2023, 2:30pm UTC](https://boards.straightdope.com/t/what-to-do-with-with-dead-bodies-on-generation-ships/985514/201 "2023-08-15T14:30:18Z")
> [@thorny\_locust](#): > > We’ll almost certainly be somebody else long before then, if our descendents survive. But that’s also true if we just stay here on Earth, so worrying about this is a bit of a wash. ---
**Author:** ![thorny\_locust](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/thorny_locust/32/431_2.png) [@thorny\_locust](https://boards.straightdope.com/u/thorny_locust)\ **Post date:** [August 15, 2023, 2:35pm UTC](https://boards.straightdope.com/t/what-to-do-with-with-dead-bodies-on-generation-ships/985514/202 "2023-08-15T14:35:44Z")
True – except that most people talking about populating the galaxy that way seem to think that we’d be populating it with Us: members of our current human species. And the Fermi Paradox as discussed also usually seems to assume that whatever species fills up the galaxy does so while remaining one species; some even seem to assume one civilization. Also – different species, or even different civilizations, are unlikely to keep on with the original plan; even if they’re physically able to do so. ---
**Author:** ![Horatius](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/horatius/32/3572_2.png) [@Horatius](https://boards.straightdope.com/u/Horatius)\ **Post date:** [August 15, 2023, 2:42pm UTC](https://boards.straightdope.com/t/what-to-do-with-with-dead-bodies-on-generation-ships/985514/203 "2023-08-15T14:42:58Z")
> [@thorny\_locust](#): > > True – except that most people talking about populating the galaxy that way seem to think that we’d be populating it with Us: members of our current human species. Well, that’s true of the various seed ship designs. Pretty much by definition, they’ll be carrying DNA that is identical to ours, at the moment we send them out. But everyone who believes in evolution and/or genetic engineering will understand that they’ll start to diverge almost immediately. Hell, with genetic engineering, I’d expect that. No host planet is likely to be perfect for average Earth-normal humans, so I’d expect at least a few tweaks to be made, even in the first generation, to handle more/less oxygen, gravity, radiation, toxins, or whatever. ---
**Author:** ![Babale](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/babale/32/15666_2.png) [@Babale](https://boards.straightdope.com/u/Babale)\ **Post date:** [August 15, 2023, 3:28pm UTC](https://boards.straightdope.com/t/what-to-do-with-with-dead-bodies-on-generation-ships/985514/204 "2023-08-15T15:28:32Z")
> [@thorny\_locust](#): > > True – except that most people talking about populating the galaxy that way seem to think that we’d be populating it with Us: members of our current human species. And the Fermi Paradox as discussed also usually seems to assume that whatever species fills up the galaxy does so while remaining one species; some even seem to assume one civilization. That’s like saying that the pilgrims were wasting their time because Americans are not them. Our descendants will, given enough time, be completely different from us, perhaps completely unrecognizable. If there is no alien life in the galaxy, but we expand across the galaxy, different groups of humans meeting on the far edge of the galaxy might find themselves completely alien from each other - like a ring species on steroids. > **[Ring species](https://en.m.wikipedia.org/wiki/Ring_species)** > > In biology, a ring species is a connected series of neighbouring populations, each of which interbreeds with closely sited related populations, but for which there exist at least two "end populations" in the series, which are too distantly related to interbreed, though there is a potential gene flow between each "linked" population and the next. Such non-breeding, though genetically connected, "end populations" may co-exist in the same region (sympatry) thus closing a "ring". The German term R Ri... Unless one is obsessed with genetic purity in a distastefully eugenical sense, I don’t see the harm in this. ---
**Author:** ![thorny\_locust](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/thorny_locust/32/431_2.png) [@thorny\_locust](https://boards.straightdope.com/u/thorny_locust)\ **Post date:** [August 15, 2023, 4:31pm UTC](https://boards.straightdope.com/t/what-to-do-with-with-dead-bodies-on-generation-ships/985514/205 "2023-08-15T16:31:17Z")
I’m just pointing it out; in part because many people suggesting this do seem to be positing recognizable humans all the way along (though I don’t know whether those in this thread do); and partly because many people suggesting it seem to think that the basic mission will remain the same (or at least essentially similar) for thousands, hundreds of thousands, even millions of years. Personally, while I hope we have descendents, I want them to be significantly different from us. The existing species is doing way too much damage, to its own members and to everybody else. ---
**Author:** ![Lucas\_Jackson](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/lucas_jackson/32/303_2.png) [@Lucas\_Jackson](https://boards.straightdope.com/u/Lucas_Jackson)\ **Post date:** [August 15, 2023, 10:30pm UTC](https://boards.straightdope.com/t/what-to-do-with-with-dead-bodies-on-generation-ships/985514/206 "2023-08-15T22:30:13Z")
> [@Mangetout](#): > > I’m not really talking about damage. I just don’t see the point of creating something we’ll never see. I don’t think people are suggesting that they are proposing it out some direct benefit they will see, but rather a backup of sentient intelligence in the universe in general. As of right now, we know of no other intelligence in the universe. And while statistics lean toward there being other beings, there is also the chance that we are it. Not putting all of our eggs in one basket, so to speak, in case another asteroid wipes us out. Now, while you personally, might not share this view, there are others that do and are willing to act altruistically (not that I think it’s reasonable to assume it’s possible at this stage of our development, but surely one day it will be. Imagine, for example, if you could sketch out the basics of getting a man to the moon to the builders of the pyramids. They might agree it was theoretically possible, but practically - no way.) Anyway, we are already involved in projects of the like. [Norway’s “Doomsday” Vault](https://en.wikipedia.org/wiki/Svalbard_Global_Seed_Vault), for instance. “The Seed Vault provides long-term storage of duplicates of seeds conserved in genebanks around the world. This provides security of the world’s food supply against the loss of seeds in genebanks due to mismanagement, accident, equipment failures, funding cuts, war, sabotage, disease and natural disasters.” It was built in 2006 at a cost of $12,500,00 (US, current). The thousands of of people who were involved in it’s design and construction will probably never reap the benefits of their labor. Yet, they built it anyway. ---
**Author:** ![DSeid](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/dseid/32/20194_2.png) [@DSeid](https://boards.straightdope.com/u/DSeid)\ **Post date:** [August 16, 2023, 4:39am UTC](https://boards.straightdope.com/t/what-to-do-with-with-dead-bodies-on-generation-ships/985514/207 "2023-08-16T04:39:58Z")
> [@eburacum45](#): > > Then you need to consider the trophic levels in the closed environment on board the ship. If you use saprophytes to break down organic material, the amount of available energy in that material decreases somewhat. Any closed environmental life-support system needs an input of energy into that system, either in the form of chemical energy or light energy, otherwise you will be stuck with diminishing returns and decreasing amounts of food. I need this explained a bit more. My take - Waste biomass, be it bodies, plant debris, whatever … is going to be broken down. Compost it and some significant energy is putatively lost as heat. (Putatively because maybe that heat is of use.) New energy is then brought in to the system, running lights on the algae tanks, or otherwise. IF that heat from decomposition is actually lost energy, well that is loss we want to minimize. Using fungi recaptures it. Of course it’s not a perpetual motion machine. More like hybrid car using regenerative braking, with fungi as the regen and light or other energy input as the gas engine and the energy in biomass at start as the battery starting up charged. ---
**Author:** ![Mangetout](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/mangetout/32/19_2.png) [@Mangetout](https://boards.straightdope.com/u/Mangetout)\ **Post date:** [August 16, 2023, 7:43am UTC](https://boards.straightdope.com/t/what-to-do-with-with-dead-bodies-on-generation-ships/985514/208 "2023-08-16T07:43:00Z")
> [@Lucas\_Jackson](#): > > Now, while you personally, might not share this view, there are others that do and are willing to act altruistically I’m not even sure the notion of seed ships to other planets really qualifies as altruism. It seems pretty hubristic for humans to assume that the universe requires a backup of humanity. Seed banks here on Earth are not the same phenomenon at all; those are intended… well, as you say: > [@Lucas\_Jackson](#): > > This provides security of the world’s food supply ---
**Author:** ![Mangetout](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/mangetout/32/19_2.png) [@Mangetout](https://boards.straightdope.com/u/Mangetout)\ **Post date:** [August 16, 2023, 7:53am UTC](https://boards.straightdope.com/t/what-to-do-with-with-dead-bodies-on-generation-ships/985514/209 "2023-08-16T07:53:14Z")
> [@DSeid](#): > > …with fungi as the regen and light or other energy input… Light input from where? If it’s a generation ship travelling between stars, it’s not going to be getting much sunlight; there will need to be some onboard energy supply - I think that was @eburacum45 's point. Maybe it would be part of the interstellar drive systems (like a fusion power plant or some such). ---
**Author:** ![eburacum45](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/eburacum45/32/8690_2.png) [@eburacum45](https://boards.straightdope.com/u/eburacum45)\ **Post date:** [August 16, 2023, 8:38am UTC](https://boards.straightdope.com/t/what-to-do-with-with-dead-bodies-on-generation-ships/985514/210 "2023-08-16T08:38:04Z")
> [@DSeid](#): > > New energy is then brought in to the system, running lights on the algae tanks, or otherwise. Exactly. Fungi and other saphrophytes are a vital part of the process, but you need to add energy to the system (in the form of lights in the algae tanks, or growlights in the greenhouses, and so on). Otherwise you lose energetic content in the food and starve. We can’t live by mushrooms alone. Another possibility is chemical synthesis of nutrients - you could perhaps live on yeast, fungi or bacteria products, if you could artificially synthesise the chemical compounds to feed these organisms without using light. I haven’t seen much research into food production that doesn’t require light of some sort, but I expect it could be done, one way or another. In any case it doesn’t sound very appealing. ---
**Author:** ![eburacum45](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/eburacum45/32/8690_2.png) [@eburacum45](https://boards.straightdope.com/u/eburacum45)\ **Post date:** [August 16, 2023, 9:13am UTC](https://boards.straightdope.com/t/what-to-do-with-with-dead-bodies-on-generation-ships/985514/211 "2023-08-16T09:13:13Z")
Here’s one process that doesn’t use light- electrochemical production of acetates, which can be used to feed algae, yeast and fungal mycelium. [https://www.biotechniques.com/plant-climate-science/grow-in-the-dark-photosynthesis-that-doesnt-require-sunlight/](https://www.biotechniques.com/plant-climate-science/grow-in-the-dark-photosynthesis-that-doesnt-require-sunlight/) If we are going to colonise the Oort cloud and spread from star to star that way, then electrocatalysis of food might be the way forward. ---
**Author:** ![thorny\_locust](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/thorny_locust/32/431_2.png) [@thorny\_locust](https://boards.straightdope.com/u/thorny_locust)\ **Post date:** [August 16, 2023, 1:08pm UTC](https://boards.straightdope.com/t/what-to-do-with-with-dead-bodies-on-generation-ships/985514/212 "2023-08-16T13:08:37Z")
> [@eburacum45](#): > > Another possibility is chemical synthesis of nutrients - you could perhaps live on yeast, fungi or bacteria products, if you could artificially synthesise the chemical compounds to feed these organisms without using light. That process would also need energy. ---
**Author:** ![Babale](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/babale/32/15666_2.png) [@Babale](https://boards.straightdope.com/u/Babale)\ **Post date:** [August 16, 2023, 1:36pm UTC](https://boards.straightdope.com/t/what-to-do-with-with-dead-bodies-on-generation-ships/985514/213 "2023-08-16T13:36:37Z")
The only question (for an advanced enough society) is whether natural processes such as photosynthesis are as efficient as is possible, or if we can artificially do better. If artificial processes do a better job then plants, then chemically synthesizing nutrients would be viable. I think it would take some advanced biochemical knowledge to really weigh in on whether or not a more efficient method for converting energy to nutrients is possible. I believe that photosynthesis wastes quite a lot of the sunlight energy it works with, but I have no idea whether a process that’s more efficient and that chemically captures the energy in bonds we can break down (ie digest) is actually feasible. ---
**Author:** ![Bosda\_Di\_Chi\_of\_Tricor](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/bosda_di_chi_of_tricor/32/16845_2.png) [@Bosda\_Di\_Chi\_of\_Tricor](https://boards.straightdope.com/u/Bosda_Di_Chi_of_Tricor)\ **Post date:** [August 16, 2023, 1:52pm UTC](https://boards.straightdope.com/t/what-to-do-with-with-dead-bodies-on-generation-ships/985514/214 "2023-08-16T13:52:41Z")
Store a DNA sample for cloning, to keep the genepool diverse. ---
**Author:** ![eburacum45](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/eburacum45/32/8690_2.png) [@eburacum45](https://boards.straightdope.com/u/eburacum45)\ **Post date:** [August 16, 2023, 3:08pm UTC](https://boards.straightdope.com/t/what-to-do-with-with-dead-bodies-on-generation-ships/985514/215 "2023-08-16T15:08:26Z")
> [@thorny\_locust](#): > > That process would also need energy. Of course. If electrocatalysis of nutrient chemicals turns out to be as efficient as, or more efficient than, photosynthesis, then it would be a useful tool in the process of food production. If not, not. Note that photosynthesis also produces oxygen and removes carbon dioxide, so it has multiple useful attributes. ---
**Author:** ![Horatius](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/horatius/32/3572_2.png) [@Horatius](https://boards.straightdope.com/u/Horatius)\ **Post date:** [August 16, 2023, 3:11pm UTC](https://boards.straightdope.com/t/what-to-do-with-with-dead-bodies-on-generation-ships/985514/216 "2023-08-16T15:11:25Z")
> [@thorny\_locust](#): > > That process would also need energy. If we have the capacity to launch an interstellar ship, energy for food production would probably be a rounding error. Using this site: > **[relativistic kinetic energy calculator - Wolfram|Alpha](https://www.wolframalpha.com/input?i=relativistic%2Bkinetic%2Benergy%2Bcalculator)** > > Wolfram|Alpha brings expert-level knowledge and capabilities to the broadest possible range of people—spanning all professions and education levels. The energy to accelerate 100kg to 0.1c is 4.5278×10^16 joules, which is equivalent to 12 577 222.2 megawatt hours. That’s the equivalent of a 100 megawatt reactor running for over 14 years straight. If we can move a starship massing enough to support a living population of any decent size, energy isn’t going to be a problem. developing that energy source in the first place? That might be a minor issue. ---
**Author:** ![DSeid](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/dseid/32/20194_2.png) [@DSeid](https://boards.straightdope.com/u/DSeid)\ **Post date:** [August 16, 2023, 6:24pm UTC](https://boards.straightdope.com/t/what-to-do-with-with-dead-bodies-on-generation-ships/985514/217 "2023-08-16T18:24:06Z")
> [@Horatius](#): > > If we have the capacity to launch an interstellar ship, energy for food production would probably be a rounding error. That claim has been made before in this thread but I’m not sure it is true. Yes the amount per year is a relatively small amount but this small bleed is happening for potentially hundreds of thousands of years. I haven’t done the math but I suspect it can add up. Which brings up the thought of evolution, biological and just cultural, in a fairly small environment for that length of time. It seems that stagnation is a real risk. Or conflicts that destroy the venture from within as us and them tribes develop as is our nature. ---
**Author:** ![Lucas\_Jackson](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/lucas_jackson/32/303_2.png) [@Lucas\_Jackson](https://boards.straightdope.com/u/Lucas_Jackson)\ **Post date:** [August 16, 2023, 6:48pm UTC](https://boards.straightdope.com/t/what-to-do-with-with-dead-bodies-on-generation-ships/985514/218 "2023-08-16T18:48:59Z")
> [@Mangetout](#): > > I’m not even sure the notion of seed ships to other planets really qualifies as altruism. It seems pretty hubristic for humans to assume that the universe requires a backup of humanity. No one is suggesting the universe _needs_ humanity. It is not hubristic, it’s human nature, in fact, it’s life’s biological imperative to reproduce and protect the species. It’s bred into us through evolution. You yourself have done it. I think the whole idea that “humans aren’t special” is flawed. That life, intelligent enough to contemplate it’s existence and the possible existence of beings on other worlds, arose from completely inanimate non-living matter is a very special thing indeed. And even if there are other similar being somewhere, that doesn’t cancel out our uniqueness. I’m not alone in this either, many prominent physicists also hold this view, Brian Cox for example. But this is a philosophical debate - there is no right or wrong answer. Some folks like to contemplate the possibilities, there’s nothing wrong with that. If you choose think seed ships are folly, that’s OK too. > [@Mangetout](#): > > Seed banks here on Earth are not the same phenomenon at all It is. It addresses your point that you didn’t see the point of doing something you wouldn’t benefit from and that would benefit future generations. ---
**Author:** ![DSeid](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/dseid/32/20194_2.png) [@DSeid](https://boards.straightdope.com/u/DSeid)\ **Post date:** [August 17, 2023, 2:15pm UTC](https://boards.straightdope.com/t/what-to-do-with-with-dead-bodies-on-generation-ships/985514/219 "2023-08-17T14:15:23Z")
> [@Horatius](#): > > support a living population of any decent size, So if I have the time I’d like to take a stab at calculating how much energy would be required to maintain that population: what’s considered a decent size living population? 10,000? I could be off by an order of magnitude either way I think. Rough it 3000 KCal per day is about a million KCal per person each year or 4.2 ish x 10^9 joules. Multiply by 10^4 people and 10^5 years … 4.2 x 10^18 joules? More than rounding error unless I messed up which I could have. ---
**Author:** ![DSeid](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/dseid/32/20194_2.png) [@DSeid](https://boards.straightdope.com/u/DSeid)\ **Post date:** [August 17, 2023, 2:50pm UTC](https://boards.straightdope.com/t/what-to-do-with-with-dead-bodies-on-generation-ships/985514/220 "2023-08-17T14:50:55Z")
Now the order of magnitude on the other side is how many times the 100kg payload … [Previous page](https://boards.straightdope.com/t/what-to-do-with-with-dead-bodies-on-generation-ships/985514.md?page=10) [Next page](https://boards.straightdope.com/t/what-to-do-with-with-dead-bodies-on-generation-ships/985514.md?page=12)