Generation vs Colony vs Cryo

Daryl wrote:Burning the sludge for power doesn't make sense. Even on a planet with vast stores of oxygen we are moving away from chemical reaction thermal plants. Any excess CO2 would have to be scrubbed out, at a higher energy cost.
A generation ship would have to go as close to 100% recycling as possible in all aspects to survive for decades or centuries. While that means no dumping of sludge, there is no possibility of it causing a navigational hazard anyway. Space is too huge to properly conceive. Both our solar system and the target one are independently moving, so any new flight path would be millions of kilometres away each time. A ship of say 5 kilometres wide wouldn't come near it ever.

https://www.wri.org/insights/wastewater ... atmosphere.

penny wrote:Steel pipes, pots, pans, equipment, cleaning products, beauty care products. Women's lipstick has arsenic in it. Medicines might contain arsenic. Aluminum pots and pans can be eliminated for better options, for sure. And nonstick surfaces can be flushed (pardon the pun) in favor of steel pots and pans; which will introduce heavy metals. Plumbing from steel pipes and even the reactor will introduce heavy metals.

Why would pipes be made of heavy steel or copper in the first place? First, they should be made of durable but light materials; but second, that's part of the ship's infrastructure. If they were to become a significant source of contaminant over their expected lifetime of 400 years, then the ship should have been designed without them.

Why would also anyone bring their own pots and pans as part of their mass allocation? Those should be part of the common mass allocation for everyone, made out of whatever the ship can carry an excess of, printed aboard for use and recycled. Someone may want to bring some heirloom pots and pans and cutlery sets that date back to $INSERT_CENTURY_HERE, but those would be mostly in storage not in day-to-day use. But the ones provided by or sold in the ship would be made out of materials that are safe for the ship.

But! Cleaning products will be necessary aboard ship. And I would imagine effective cleaning products would be needed. I can't speak for anyone else, but plant based laundry detergents are not my cup of tea.

Same thing: that's not your choice. You're not going to bring cleaning products aboard the ship on your mass allocation, even if you wanted to. There's no claim to "family heirloom cleaning product" and those are often explosive or could be used for other purposes. Cleaning products and tools are going to be supplied by the ship.

And you're not going to be cleaning anyway; bots will.

If those products or the pipes or whatever do contain some trace metals or whatever else that is toxic to humans and couldn't be designed out, then mitigations must be found elsewhere. Either people take inoculations or must go through cleaning or treatment.

Or they're not lethally toxic at all because they can't accumulate, as the supply is, like everything else aboard, limited. They're not churning up land aboard the ship to find new sources of heavy metals that weren't in our food chain yet. So maybe some materials leak out of the water piping system or air vent system over time or hydroponics, but they don't build up sufficiently in people over their 100 years of lifetime (or they do and they shorten that lifespan to 85 years). As those systems are clearly degrading over time, they would need servicing and possibly replacement, which would then replenish the source of material leaking out.

At any rate, I am more inclined to accept that in the HV, a better way to handle the waste has been discovered, and or the sludge is ejected into space. *

I agree on finding a better way.

*Thinksmarkedly, as far as ejected sludge being a navigation hazard, I hear you. However, if the sludge is ejected in its dry state, then only dust will be ejected into space, which will hardly be a navigation hazard. Particle screens are there to sweep dust aside.

Planets don't have particle screens. They do have atmospheres, which work much the same way. But meteors inside a system are travelling at orbital speeds and thus usually have glancing blows on planets. This sludge would be travelling at 0.5c and on a pretty much, straight-on collision course. As E=mv²/2, the relative speed being 3 orders of magnitude more make the energy released 1 million times bigger.

The Chicxulub asteroid was estimated to mass 10¹⁵ kg at the low end. So an equivalent impact at 0.5c would only require a mass of 10⁹ kg or 1 million tonnes total. Or 2500 tonnes per year, or 625 kg per person per year. Or 1.7 kg or 3.7 lb per person, per day.

I don't think the ship would produce that much sludge in the first place because it won't have 1 million tonnes to spare, but it's definitely not ejecting that.

In summary, I just do not think it is realistic to handicap the entire operation by limiting access to the right tools for the job. Industrial strength cleaning agents are necessary. Across the board.

Provided by and controlled by the ship. And used by bots.

Both Copper/Iron are absurdly easy to remove from waste.

Uh, why is either a problem? We do it industrially today.

I understand why you do not want iron, it Oxidizes and on a ship with limited oxygen... A ship made of Copper would be wonderful in comparison. Once an oxide layer forms it is fine long term. Medium strength, low galvanic corrosion, easily welded/sealed. Once arrive at destination copper would be WONDERFUL to have for wire, vessels for chemicals, etc. Of course Aluminum, Niobium, gold, nickel etc are superior, but have other problems. Aluminum especially with galvanic corrosion, and a ship full of millions of holes, would be a problem over 1000 year voyage.

So if you want a generational ship, you had better figure out how to build/seal a generational ship using materials which have already "burned" and which can be easily patched due to meteorite impacts

Oh and why is CO2 a problem? You need food. CO2 collected and bubbled through tanks of Algae-->shrimp or fish-->food and in hydroponics sections sitting at 10,000ppm or higher CO2 will cause plants to explode in growth rate assuming there is enough light/minerals from the microbes collected probably by a running bath of microryzal fungi/bacteria chomping down on the CO2 and CH4 for them to eat from the hydrocarbons out of the root enzymes of said plant or air itself.

Now REGULATING all this biologically
All about the Command and Controls is the actual problem here.

All power based.

Relax wrote:Both Copper/Iron are absurdly easy to remove from waste.

Uh, why is either a problem? We do it industrially today.

I understand why you do not want iron, it Oxidizes and on a ship with limited oxygen... A ship made of Copper would be wonderful in comparison. Once an oxide layer forms it is fine long term. Medium strength, low galvanic corrosion, easily welded/sealed. Once arrive at destination copper would be WONDERFUL to have for wire, vessels for chemicals, etc. Of course Aluminum, Niobium, gold, nickel etc are superior, but have other problems. Aluminum especially with galvanic corrosion, and a ship full of millions of holes, would be a problem over 1000 year voyage.

So if you want a generational ship, you had better figure out how to build/seal a generational ship using materials which have already "burned" and which can be easily patched due to meteorite impacts

Oh and why is CO2 a problem? You need food. CO2 collected and bubbled through tanks of Algae-->shrimp or fish-->food and in hydroponics sections sitting at 10,000ppm or higher CO2 will cause plants to explode in growth rate assuming there is enough light/minerals from the microbes collected probably by a running bath of microryzal fungi/bacteria chomping down on the CO2 and CH4 for them to eat from the hydrocarbons out of the root enzymes of said plant or air itself.

Now REGULATING all this biologically
All about the Command and Controls is the actual problem here.

All power based.

I don't know about "easy" but, if you will. We have complicated systems that do so today, yes. But the main argument has never been about any difficulty of removing any heavy metals. The argument has always been the problem of keeping up with production. The methods we use today are all time consuming processes. There are no magic bullets. And the heavy metal removal rarely reaches the acceptable legal limits of safety. That is part and parcel of why the disposal of the sludge at the end of the treatment cycle is still problematical. As a result, I suppose it is not so easy. Not by todays technology when trying to keep up with production demands. Aboard a generation ship, production demands will be much higher. And the available space for processing will not increase as demands increase.

Time consuming? Hardly, via mechanical/chemical processes. Unless you are talking specifically about trying to sort sludge materials biologically?(This is unclear in your post) Sludge materials would NOT need to be sorted(initially) at all biologicially. You let the bacteria/microryzal fungi eat the materials in the quantities they want to give to plants. If certain elements build in %(not many have an unsafe limit as most get fixed via oxygen or carbon/silicon for instance and why the whole idea of a toxic planet like Grayson is for the most part a big joke except the dust component or aquatic species which is a death knell for those species of plant/animal and why Grayson or such a planet may have no plant/animal life at all as life could never get started to begin with)

Sludge: YOU MELT it, spit it out under HIGH pressure(forget term? Spackle? Sputter? I think it is sputter... Been a long time since I have done this in lab or been around those who did this at the industrial level) into pure water or pure nitrogen/oxygen and powder ~it dissaociates into constituent elements at ~+95% purity which for MAJORITY of applications is perfectly acceptable/good for a remelt to remove anything else or to mix into what you want and use gravity to sort(oscillations or dynamically(spin) on a ship in zero G). Only reason we do not do it ALL the time is virgin materials are MUCH cheaper. The expensive part is setting up the equipment originally, not the energy in question.

Anything iron based is easy to remove as it is magnetic unlike most other materials, though this depends on guassian levels, temperatures.

Most everything in engineering is purely limited by initial up front costs, not the possibility of the implementing the idea. Once the upfront costs are sunk, solution found, the upkeep costs are dirt cheap.

Look at the whole EV debate or the idiotic belief by the public that we have had giant advances in battery tech energy density... what a Joke... Energy density of Lithium Ion batteries has not changed significantly other than at the margins regarding anodes for the most part in going on 30+ years... ~+200Wh/kg 30+ years ago and today it is ~+200Wh/kg. Rather the INDUSTRIAL capacity for common JOE/JILL to have them in their hands has taken time to build.... or changing from Gasoline/diesel to -->'X'... it truly has not much to do with limitations of the technology but rather availability(cost and ubiquitous nature) of materials. Not in aircaft's case which need energy density the above is not true, but... Ships? We could have been using aluminum iron chemical reaction "batteries" for ship transport across the ocean blue many decades ago. The problem is initial expense of making enough available ANYONE can have a giant stockpile of this at EVERY port worldwide which is why for my lifetime and remaining of yours, ocean transport will be oil based.

Maybe someone will get smart and figure out that average wind speed across ocean blue is ~15--20 knots and a pair of wind turbines which we already have today would provide at least 50%-->100% of the power necessary to move said ships at 15 knots across the ocean blue on most routes... Herein lies the problem, it is not a UBIQUITOUS solution--> Therefore said "solution" is Dead on Arrival as model for shipping is identical ships in identical port facilities produced from ~identical industrial plants and a dual system would cost ~2X as much to initially setup and maintain indefinetly going forward and paying 2X for shipping costs = ### Ain't gonna happen folks.

Hrmm enough rambling... Bed

ThinksMarkedly wrote:

penny wrote:Steel pipes, pots, pans, equipment, cleaning products, beauty care products. Women's lipstick has arsenic in it. Medicines might contain arsenic. Aluminum pots and pans can be eliminated for better options, for sure. And nonstick surfaces can be flushed (pardon the pun) in favor of steel pots and pans; which will introduce heavy metals. Plumbing from steel pipes and even the reactor will introduce heavy metals.

Why would pipes be made of heavy steel or copper in the first place? First, they should be made of durable but light materials; but second, that's part of the ship's infrastructure. If they were to become a significant source of contaminant over their expected lifetime of 400 years, then the ship should have been designed without them.

Why would also anyone bring their own pots and pans as part of their mass allocation? Those should be part of the common mass allocation for everyone, made out of whatever the ship can carry an excess of, printed aboard for use and recycled. Someone may want to bring some heirloom pots and pans and cutlery sets that date back to $INSERT_CENTURY_HERE, but those would be mostly in storage not in day-to-day use. But the ones provided by or sold in the ship would be made out of materials that are safe for the ship.

But! Cleaning products will be necessary aboard ship. And I would imagine effective cleaning products would be needed. I can't speak for anyone else, but plant based laundry detergents are not my cup of tea.

Same thing: that's not your choice. You're not going to bring cleaning products aboard the ship on your mass allocation, even if you wanted to. There's no claim to "family heirloom cleaning product" and those are often explosive or could be used for other purposes. Cleaning products and tools are going to be supplied by the ship.

And you're not going to be cleaning anyway; bots will.

If those products or the pipes or whatever do contain some trace metals or whatever else that is toxic to humans and couldn't be designed out, then mitigations must be found elsewhere. Either people take inoculations or must go through cleaning or treatment.

Or they're not lethally toxic at all because they can't accumulate, as the supply is, like everything else aboard, limited. They're not churning up land aboard the ship to find new sources of heavy metals that weren't in our food chain yet. So maybe some materials leak out of the water piping system or air vent system over time or hydroponics, but they don't build up sufficiently in people over their 100 years of lifetime (or they do and they shorten that lifespan to 85 years). As those systems are clearly degrading over time, they would need servicing and possibly replacement, which would then replenish the source of material leaking out.

At any rate, I am more inclined to accept that in the HV, a better way to handle the waste has been discovered, and or the sludge is ejected into space. *

I agree on finding a better way.

*Thinksmarkedly, as far as ejected sludge being a navigation hazard, I hear you. However, if the sludge is ejected in its dry state, then only dust will be ejected into space, which will hardly be a navigation hazard. Particle screens are there to sweep dust aside.

Planets don't have particle screens. They do have atmospheres, which work much the same way. But meteors inside a system are travelling at orbital speeds and thus usually have glancing blows on planets. This sludge would be travelling at 0.5c and on a pretty much, straight-on collision course. As E=mv²/2, the relative speed being 3 orders of magnitude more make the energy released 1 million times bigger.

The Chicxulub asteroid was estimated to mass 10¹⁵ kg at the low end. So an equivalent impact at 0.5c would only require a mass of 10⁹ kg or 1 million tonnes total. Or 2500 tonnes per year, or 625 kg per person per year. Or 1.7 kg or 3.7 lb per person, per day.

I don't think the ship would produce that much sludge in the first place because it won't have 1 million tonnes to spare, but it's definitely not ejecting that.

In summary, I just do not think it is realistic to handicap the entire operation by limiting access to the right tools for the job. Industrial strength cleaning agents are necessary. Across the board.

Provided by and controlled by the ship. And used by bots.

It doesn't matter. Any material is going to introduce unwanted pollutants, either in the process of making the material, utilizing the material (fastening and or installing, etc.) or treating the material, etc. There are just too many avenues of introduction of contaminants. There is no getting around it.

Consider this innocent introduction of contaminants.

https://abcnews.go.com/GMA/Food/massive ... =106250289

https://www.yahoo.com/entertainment/sci ... 13109.html

The best cleaning agents are the ones that are toxic. Industrial strength cleaning needs, require industrial strength cleaners.

Again, I hear what you are saying about ejecting solids from the ship, but I find it impossible to believe that dust, even traveling at .5C is going to become a problem to some planet. Certainly not the planet the generation ship is heading to, unless it can make several course corrections.

But it can become a problem to another planet if it would hit another planet in its concentrated form. But I doubt that would happen. Or earth would have been bombarded by the solid matter of supernovae again and again. I just cannot see space dust holding together and not being affected by gravity throughout its long journey in such a huge medium.

penny wrote:Any material is going to introduce unwanted pollutants, either in the process of making the material, utilizing the material (fastening and or installing, etc.) or treating the material, etc. There are just too many avenues of introduction of contaminants. There is no getting around it.

-- skip --

The best cleaning agents are the ones that are toxic. Industrial strength cleaning needs, require industrial strength cleaners.

From Wikipedia:

Chromium, arsenic, cadmium, mercury, and lead have the greatest potential to cause harm on account of their extensive use, the toxicity of some of their combined or elemental forms, and their widespread distribution in the environment

We are not discussing all pollutants, only those most likely to cause long term harm to the inhabitants of a closed environment. You keep talking about industrial cleaners, but can you list those cleaners that you find essential, which contain one or more of the elements listed in that quote from Wikipedia? The problem is not toxicity, hydrochloric acid is toxic, but those compounds that accumulate in the body and cause long term damage.

A search of articles suggests that it is mostly industrial processes which introduce the heavy metals that cause the problems with sludge. I expect that such processes will not be used on the colony ship.

tlb wrote:

penny wrote:Any material is going to introduce unwanted pollutants, either in the process of making the material, utilizing the material (fastening and or installing, etc.) or treating the material, etc. There are just too many avenues of introduction of contaminants. There is no getting around it.

-- skip --

The best cleaning agents are the ones that are toxic. Industrial strength cleaning needs, require industrial strength cleaners.

From Wikipedia:

Chromium, arsenic, cadmium, mercury, and lead have the greatest potential to cause harm on account of their extensive use, the toxicity of some of their combined or elemental forms, and their widespread distribution in the environment

We are not discussing all pollutants, only those most likely to cause long term harm to the inhabitants of a closed environment. You keep talking about industrial cleaners, but can you list those cleaners that you find essential, which contain one or more of the elements listed in that quote from Wikipedia? The problem is not toxicity, hydrochloric acid is toxic, but those compounds that accumulate in the body and cause long term damage.

A search of articles suggests that it is mostly industrial processes which introduce the heavy metals that cause the problems with sludge. I expect that such processes will not be used on the colony ship.

For any Colony, there are 2 conditions: On the Ship and on the Colony world. On the Ship they should be able to limit the the number of items that will cause toxicity, and plan for those issues. On the Colony, they can bring the tools to take care of those they plan to expect, and have plans for other tools an/or banks of a wide array of genetically modified plants/miro-organisms designed for other issues.