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#51 2018-07-10 22:31:43

JoshNH4H
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From: Pullman, WA
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Re: Self-replicating colony - a challenge but how difficult?

This is something I've thought a lot about and which I have a number of thoughts on, so I'd like to contribute them here.

1. Creating a "backup" for humanity is something that has real value...

But I don't think this is a good way to justify a human settlement on Mars or anywhere else.  I think it also has plenty of implications which are hard to think through.  We live in a world with finite amounts of human time and resources available, and we make decisions about how to apply these (ideally for the best possible use).  In order to say that we should settle Mars because it creates a backup for the human species and human civilization (or at least the one or ones that build the settlements), you need to think the following things:

  • The existence of living humans or the survival of a social genome has value that is not just inherent, but very large

  • That for whatever amount of resources you want to dedicate to the settlement project (possibly hundreds of billions of dollars or more!) settlement of another planet has the highest possible expected value of preserving that.  So, for example, let's say settlement reduces the probability of total destruction by a factor of 10 (settlements fail sometimes, after all, and the sudden end of interaction with Earth would be a substantial blow even if you have planned for it)--that there is no better way (bunkers come to mind, of course, but you could also build an asteroid defense system and create measures to prevent nuclear war as well) to do so.

  • And that you don't need to see comprehensive settlement, that you're fine with whatever the minimum viable settlement size is.

I think it's hard to confidently argue all three of those, and even if you do I don't think you end up with the kind of settlement that we really have in mind.  I consider it to be something of a secondary benefit--A good thing that nevertheless cannot and should not justify settlement by itself.

2. The ability to self-replicate (indeed, to expand and improve) is a fundamental requirement for any prosperous settlement or society anywhere.  This absolutely holds, in the strongest sense, for Mars.  Even if we ignore the abstract requirements for settlements in general, Mars is so far away and so hard to get to that any rational cost-benefit analysis will suggest that the bulk of the items consumed on Mars must also be produced there. 

3. However no system in this universe is completely closed to outside inputs.  In traditional economics, the thing we're talking about here is called "autarky".  It hasn't existed in any advanced society on Earth, but Mars is pretty unique as far as the combination of high technology and high travel costs (On Earth, high technology has increasingly tended to reduce travel times and costs to levels where extensive international trade is economically desirable even far away from immediate borders; On Mars, high tech makes settlement possible even as trade is much less feasible).  The physical limit to self sufficiency is the requirement for an energy input. 

In the real world (and I have definitely said this before) practicality suggests you might try to trade for high value-low mass components.  Things that are hard to manufacture, will only be manufactured in low volumes, or have no mass at all (i.e. certain kinds of services that can be done about as well on Earth as on Mars)  This would imply a need for export goods and/or services, or ongoing financial support from Earth.

4. To the extent that you approach self-sufficient replication, you do so asymptotically.  For a given measure of closure, it will require more and more effort on the part of any settlement or society to get closer and closer to complete closure.  Any reasonable group of people concerned with their own welfare and survival will decide at a certain point that they have enough closure.  What this "enough" level is (If Earth is suddenly rendered useless for whatever reason, does the settlement fail or is there a small decline in the standard of living and temporary shortages in certain products?) is quite hard if not impossible to say in advance.

5. There are limits to what we can know and guess at as people sitting behind keyboards on Earth.  The range of possibilities for self-replication lies between "difficult but doable" and "virtually impossible", and anyone who claims to know better probably doesn't know very much at all.


-Josh

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#52 2018-07-20 16:35:24

louis
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From: UK
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Re: Self-replicating colony - a challenge but how difficult?

Some interesting thoughts...

JoshNH4H wrote:

This is something I've thought a lot about and which I have a number of thoughts on, so I'd like to contribute them here.

1. Creating a "backup" for humanity is something that has real value...

But I don't think this is a good way to justify a human settlement on Mars or anywhere else.  I think it also has plenty of implications which are hard to think through.  We live in a world with finite amounts of human time and resources available, and we make decisions about how to apply these (ideally for the best possible use).  In order to say that we should settle Mars because it creates a backup for the human species and human civilization (or at least the one or ones that build the settlements), you need to think the following things:

  • The existence of living humans or the survival of a social genome has value that is not just inherent, but very large

  • That for whatever amount of resources you want to dedicate to the settlement project (possibly hundreds of billions of dollars or more!) settlement of another planet has the highest possible expected value of preserving that.  So, for example, let's say settlement reduces the probability of total destruction by a factor of 10 (settlements fail sometimes, after all, and the sudden end of interaction with Earth would be a substantial blow even if you have planned for it)--that there is no better way (bunkers come to mind, of course, but you could also build an asteroid defense system and create measures to prevent nuclear war as well) to do so.

  • And that you don't need to see comprehensive settlement, that you're fine with whatever the minimum viable settlement size is.

I think it's hard to confidently argue all three of those, and even if you do I don't think you end up with the kind of settlement that we really have in mind.  I consider it to be something of a secondary benefit--A good thing that nevertheless cannot and should not justify settlement by itself.

I think by definition humanity is of interest to humans.  We all have a stake in this.

The allocation of resources is not a zero sum game.  Mars would not be asking Coca Cola to allocate more resources to marketing, or universities to allocate more money to research or Earth TV companies  to allocate more money to programming or Earth governments to raise more taxes.  Mars will simply reorder the priorities of people back on Earth, that's all and that will free up tens of billions of dollars for Mars colonial development. 

2. The ability to self-replicate (indeed, to expand and improve) is a fundamental requirement for any prosperous settlement or society anywhere.  This absolutely holds, in the strongest sense, for Mars.  Even if we ignore the abstract requirements for settlements in general, Mars is so far away and so hard to get to that any rational cost-benefit analysis will suggest that the bulk of the items consumed on Mars must also be produced there.

Yes, I think that is true.  Musk has done well in putting together a Mission that can deliver hundreds of tonnes to Mars but you can't easily expand that model to serve a community of thousands or tens of thousands on Mars.  So, clearly ISRU has to assume a bigger and bigger role. The increasing rate of ISRU will have to resemble the hockey graph template.

3. However no system in this universe is completely closed to outside inputs.  In traditional economics, the thing we're talking about here is called "autarky".  It hasn't existed in any advanced society on Earth, but Mars is pretty unique as far as the combination of high technology and high travel costs (On Earth, high technology has increasingly tended to reduce travel times and costs to levels where extensive international trade is economically desirable even far away from immediate borders; On Mars, high tech makes settlement possible even as trade is much less feasible).  The physical limit to self sufficiency is the requirement for an energy input. 

In the real world (and I have definitely said this before) practicality suggests you might try to trade for high value-low mass components.  Things that are hard to manufacture, will only be manufactured in low volumes, or have no mass at all (i.e. certain kinds of services that can be done about as well on Earth as on Mars)  This would imply a need for export goods and/or services, or ongoing financial support from Earth.

Yes. I more or less agree with what you say.  Depends what you mean by "outside inputs" of course - all Earth economies are essentially dependent on the Sun and, to a much lesser degree, the Moon. There is no particular reason for Mars to aim for autarky in reality - but it would probably be a useful Plan B should the Earth suffer some horrendous asteroid impact or other massive catastrophe that might wipe out technical civilisation. So in reality, you are aiming for a Mars that is so technically advanced, that - if Earth should shut down - it could then step up a gear or two  to full self-replication. But in the absence of an Earth catastrophe, it makes no sense to try and say create on Mars beef herds, an Earth-like computer industry, a second Big Pharma industry or fullly biodiverse Amazonian tropical forest.

I think people who comment here on the economic potential of Mars tend to underestimate the huge potential of a planet with all those resources.  You have to think about how investment, sponsorship, cultural interest, scientific interest, commercial exploitation, tourism, international competition between states and new opportunities for profit will all interact.  I have previously mentioned Mars Rolex watch assembly on Mars incorporating some polished up Mars jewellery as a really strong contender for a start up industry. The low mass, that you point to, makes that a real runner.  But there will be lots of such opportunities, things we can't necessarily think of now.

As you say, some opportunities will be "no mass" in effect.  I could definitely see Mars becoming a design centre for a whole range of products - computer games, clothing, rockets, satellites, art products.  I can see Mars appealing to adventurous people with creative minds. And I can see it appealing to businesses - no land/building rental, no taxes.  Yes, there will be a life support payment to the Mars Corporation to allow you to operate your business on Mars but you may only be paying a marginal price there. We will have to wait and see how the economics on all that turn out.   

4. To the extent that you approach self-sufficient replication, you do so asymptotically.  For a given measure of closure, it will require more and more effort on the part of any settlement or society to get closer and closer to complete closure.  Any reasonable group of people concerned with their own welfare and survival will decide at a certain point that they have enough closure.  What this "enough" level is (If Earth is suddenly rendered useless for whatever reason, does the settlement fail or is there a small decline in the standard of living and temporary shortages in certain products?) is quite hard if not impossible to say in advance.

Indeed. There is plenty of give in the concept of survival.  As long as your food supply system can cover all nutrients, that's fine in terms of survival, even if it doesn't deliver the full taste range delivered on Earth.  Likewise with clothing, furniture, computers and so on.

Rockets are no longer required, of course.

But there is clearly a minimal survival standard and any Mars community would have to address that, just as wartime governments did across a whole range of items.

5. There are limits to what we can know and guess at as people sitting behind keyboards on Earth.  The range of possibilities for self-replication lies between "difficult but doable" and "virtually impossible", and anyone who claims to know better probably doesn't know very much at all.

Of course.  There are definitely unknowables. But certainly there are plenty of examples from Earth of survival situations e.g. sieges of towns, acute environmental stress (e.g. the Vikings in Greenland), and wartime deprivation. A common factor in survival is of course "looking for alternatives" whether it be novel foodstuffs (rats instead of beef cuts) or ersatz rubber or alternative modes of production (the Japanese kept their air force airborne in 1945 on pine oil I believe it was).   

Given the Mars community would not be facing a malevolent enemy, one assumes, I think their chances of survival would be very good, assuming you have had a pretty wholesale digital transfer of our knowledge base (Library of Congress, all patents in all nations, whole of You Tube etc).


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#53 2018-07-21 11:34:28

JoshNH4H
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Re: Self-replicating colony - a challenge but how difficult?

louis wrote:

I think by definition humanity is of interest to humans.  We all have a stake in this.

Well it's maybe a bit more complicated than that.  Humanity is an idea, after all.  People definitely act in their own interests, and those of their families and friends.  Sometimes even their acquaintances and neighbors.  What I'm trying to get at is that I don't think it's much consolation to tell someone that if they and everyone they've ever known dies there will be some select group of people a hundred million miles away who are still alive. 

There's two ways to look at this.  The first is politically (If someone said that you could reduce your standard of living by a bit* to create this kind of insurance policy, would a majority of people choose to do it?) and the second is philosophically (what is the value and the cost of creating this insurance policy under the values we subscribe to, and is the value greater than the cost?).

I suspect the answer to the first question is "no", and frankly I'm not even sure how to think about the second one.  I don't think it's a trivial question.

louis wrote:

The allocation of resources is not a zero sum game.  Mars would not be asking Coca Cola to allocate more resources to marketing, or universities to allocate more money to research or Earth TV companies  to allocate more money to programming or Earth governments to raise more taxes.  Mars will simply reorder the priorities of people back on Earth, that's all and that will free up tens of billions of dollars for Mars colonial development.

In the immediate sense, the allocation of resources is a zero sum game as you have some amount of resources which you can allocate in a variety of ways.  In the long term sense it's not zero sum (certain uses of resources return more resources back in the future; other uses waste them with no utility generated and no return in future resources) but the fact remains that an investment in Mars today corresponds to a fairly direct lack of production/investment in something else.  Now you can argue that this presents the best possible return but that's a bit hard to do.

Your claim that "simply reordering priorities" will somehow free up resources without any sacrifice being made by anyone isn't right and it doesn't make sense.

*This is the case whether it is funded through taxes, which directly reduce your standard of living by reducing your income or increasing the costs of goods/services, or through private investment, insofar as there is a fixed amount of labor (particularly skilled labor) that is available, and dedicating some amount of that to the project of building towns on Mars means that there is less available for whatever else they might be doing on Earth.


-Josh

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#54 2018-07-21 13:37:46

kbd512
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Re: Self-replicating colony - a challenge but how difficult?

The ultimate resources are matter and energy.  There's no shortage of either in the inner solar system alone for the foreseeable future, but our technology for extracting resources from other places besides Earth is practically nonexistent.  Given the sheer quantities of materials in the inner solar system, we might want to accelerate the development of that sort of technology.  Given the distances, times, and resource expenditures involved with sending humans to where the resources are located, a major part of that technology has to be robotic.

We need solar powered robotic "ore miners in a can" technology to fetch the riches available, process them as required, and send them back to Earth (not necessarily the surface of the Earth, but somewhere that an orbital manufacturing facility near Earth can retrieve and build something in space.  Until we develop and perfect that sort of technology, this space colonization stuff is just science fiction.

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#55 2018-07-22 06:20:38

louis
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From: UK
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Re: Self-replicating colony - a challenge but how difficult?

It is complicated. Humanity is both a concept but also a reality both in the sense of referring to organisms that can successfully procreate with one other, at least between genders and in the sense of an inter-connected culture (even a very isolated country like North Korea is nevertheless plugged into the wider human culture).

I don't personally favour the "insurance policy" argument strongly but it does have some merit I would say.  It has even more merit if you think of it as a insurance and repair policy, in that if Mars had an advanced technical civilisation it could help Earth repair the damage of a cataclysm. If the policy is going to cost people  on Earth say half a cent a day per person for twenty years, I think that would help get support. But my view is that this policy comes free - Mars colonisation will pay for itself.

Personally I am more a "thrills and spills" guy...believing we should go because it will be interesting and exciting. A kind of Kennedy motive (not because it's easy, but because it's hard) but with a little more hedonism than high minded principle thrown in.

You could argue it was a zero sum game but I think it would be difficult to maintain that, since by moving to Mars you now access trillions of tonnes of resources previously not accessible and also land that the humans on Mars would otherwise be occupying on Earth. Also if Mars has its own currency, then everything can be freely exchanged. If a university decides it wants to spend $10million on a research project on Mars rather than in Antarctica  does it make sense to say Antarctica is £10m poorer? I don't think so, anymore than it would make sense to say Africa was £10 m poorer if the rival project to Antarctica was based in Africa and they lost out.

JoshNH4H wrote:
louis wrote:

I think by definition humanity is of interest to humans.  We all have a stake in this.

Well it's maybe a bit more complicated than that.  Humanity is an idea, after all.  People definitely act in their own interests, and those of their families and friends.  Sometimes even their acquaintances and neighbors.  What I'm trying to get at is that I don't think it's much consolation to tell someone that if they and everyone they've ever known dies there will be some select group of people a hundred million miles away who are still alive. 

There's two ways to look at this.  The first is politically (If someone said that you could reduce your standard of living by a bit* to create this kind of insurance policy, would a majority of people choose to do it?) and the second is philosophically (what is the value and the cost of creating this insurance policy under the values we subscribe to, and is the value greater than the cost?).

I suspect the answer to the first question is "no", and frankly I'm not even sure how to think about the second one.  I don't think it's a trivial question.

louis wrote:

The allocation of resources is not a zero sum game.  Mars would not be asking Coca Cola to allocate more resources to marketing, or universities to allocate more money to research or Earth TV companies  to allocate more money to programming or Earth governments to raise more taxes.  Mars will simply reorder the priorities of people back on Earth, that's all and that will free up tens of billions of dollars for Mars colonial development.

In the immediate sense, the allocation of resources is a zero sum game as you have some amount of resources which you can allocate in a variety of ways.  In the long term sense it's not zero sum (certain uses of resources return more resources back in the future; other uses waste them with no utility generated and no return in future resources) but the fact remains that an investment in Mars today corresponds to a fairly direct lack of production/investment in something else.  Now you can argue that this presents the best possible return but that's a bit hard to do.

Your claim that "simply reordering priorities" will somehow free up resources without any sacrifice being made by anyone isn't right and it doesn't make sense.

*This is the case whether it is funded through taxes, which directly reduce your standard of living by reducing your income or increasing the costs of goods/services, or through private investment, insofar as there is a fixed amount of labor (particularly skilled labor) that is available, and dedicating some amount of that to the project of building towns on Mars means that there is less available for whatever else they might be doing on Earth.

Last edited by louis (2018-07-22 06:21:17)


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#56 2018-07-22 11:58:48

Terraformer
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Re: Self-replicating colony - a challenge but how difficult?

People live in Alaska. Not just because they have to live there for their job in tourism, mining, or government work, but because some people like to live on isolated homesteads. Get to the point where a millionaire can do the same on Mars, because resources, tourism, and science research have paid for the infrastructure and knowledge needed, and you might be able to find a few thousand out of the 15 million American millionaires who are sufficient diehard romantics to move to an isolated homestead on the red planet.

I definitely think that there would be a fair number of Mars bases, maybe a dozen, if it cost $1-2 billion/year to keep one going. The US, EU, and China would be able to afford that easily. That would take all of India's space budget, but they could afford it too. That would be within the budgets of Russia and Japan as well. Maybe CANZUK could club together on our own base.


"I guarantee you that at some point, everything's going to go south on you, and you're going to say, 'This is it, this is how I end.' Now you can either accept that, or you can get to work." - Mark Watney

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#57 2018-07-22 18:47:31

louis
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From: UK
Registered: 2008-03-24
Posts: 3,939

Re: Self-replicating colony - a challenge but how difficult?

I agree...for some the sense of relative isolation will be very attractive.

As stated many times I think a Mars Corporation would have to be a bit of a dud if it couldn't make a healthy profit from this planet with a land area similar to that of Earth, trillions of tonnes of resources and also a planet that is deeply embedded in our psyche across the world for millennia.

Space Agency contributions may well be a significant part of the Mars economy but Mars will not be dependent on them.

Terraformer wrote:

People live in Alaska. Not just because they have to live there for their job in tourism, mining, or government work, but because some people like to live on isolated homesteads. Get to the point where a millionaire can do the same on Mars, because resources, tourism, and science research have paid for the infrastructure and knowledge needed, and you might be able to find a few thousand out of the 15 million American millionaires who are sufficient diehard romantics to move to an isolated homestead on the red planet.

I definitely think that there would be a fair number of Mars bases, maybe a dozen, if it cost $1-2 billion/year to keep one going. The US, EU, and China would be able to afford that easily. That would take all of India's space budget, but they could afford it too. That would be within the budgets of Russia and Japan as well. Maybe CANZUK could club together on our own base.


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#58 2018-07-30 10:37:43

Terraformer
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Re: Self-replicating colony - a challenge but how difficult?

A self-sufficient and replicating colony on Mars would not have to  be spacefaring - it could exist at a lower technology level than was used to get there. Possibly even with the high technologies of the 1930s. Of course, they wouldn't have solar PV (they'd have to build some solar updraft towers or CSP plants), or any other semiconductor industry for that matter. Their computers would be big bulky electromechanical things. But they could do it, I think.

What key technologies are needed to build a motorbike? What elements and compounds? How many people are needed to build one from the raw materials - and by raw, I'm talking about ores here, not the refined materials.


"I guarantee you that at some point, everything's going to go south on you, and you're going to say, 'This is it, this is how I end.' Now you can either accept that, or you can get to work." - Mark Watney

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#59 2018-07-30 14:42:55

louis
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Re: Self-replicating colony - a challenge but how difficult?

They wouldn't have to be space faring, but there's no reason why a colony of 1000 couldn't produce their own PV panels. As long as they have that original technical endowment of state-of-the-art 3D printers, industrial robots, CNC lathes, a wide range of tools, highly skilled engineers, and a huge digital library of technical plans, process information, designs etc.  It would have to be a much narrower sort of economy than we are used to in advanced economies on Earth - very focussed on the key elements of energy production, metallurgy, plastics, ceramics, life support, construction and agriculture. It wouldn't be focussing much on clothes, furniture, private vehicles and so on, all of which would somewhat impede the ability to self-replicate. It could eliminate lots of Earth-style economic activity like insurance, finance and banking, commodities trading, manufacture of paper-based products, personal transport, billing, advertising, marketing, charity work, entertainment broadcasting, alcoholic and non-alcoholic beverage production, professional sport, airports and air transport, rail transport, and road building and maintenance.

We know humans can accomplish this sort of focussing e.g. in wartime economies, where the emphasis switches to war production. In this case the focus would be on the limited range of activities that facilitate utilitarian replication.

Of course, it takes a tremendous effort to establish the PV array to generate enough power (maybe averaging 50MWs during sollight), start up all the mining operations, establish all the furnaces and factories,   construct the habitats, put in place the agricultural production to produce say 600 tonnes of food per Earth year, and produce the life support systems to keep 1000 inhabitants alive. But of course, once you've done it, it is largely a question of maintenance and planned renewal.

If you had a PV array of 300,000 sq. metres powering this colony, then on a 20 Earth year renewal cycle, you'd have to replace 15,000 sq. metres per Earth year. You'd have to have a PV manufacturing facility able to produce about 300 sq. metres per week.  That sounds achievable in a 1000 person colony with all the right equipment, including the equipment to maintain and renew their PV manufacturing facility.

Terraformer wrote:

A self-sufficient and replicating colony on Mars would not have to  be spacefaring - it could exist at a lower technology level than was used to get there. Possibly even with the high technologies of the 1930s. Of course, they wouldn't have solar PV (they'd have to build some solar updraft towers or CSP plants), or any other semiconductor industry for that matter. Their computers would be big bulky electromechanical things. But they could do it, I think.

What key technologies are needed to build a motorbike? What elements and compounds? How many people are needed to build one from the raw materials - and by raw, I'm talking about ores here, not the refined materials.


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#60 2018-07-30 22:32:56

JoshNH4H
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Re: Self-replicating colony - a challenge but how difficult?

Terraformer wrote:

A self-sufficient and replicating colony on Mars would not have to  be spacefaring - it could exist at a lower technology level than was used to get there. Possibly even with the high technologies of the 1930s. Of course, they wouldn't have solar PV (they'd have to build some solar updraft towers or CSP plants), or any other semiconductor industry for that matter. Their computers would be big bulky electromechanical things. But they could do it, I think.

What key technologies are needed to build a motorbike? What elements and compounds? How many people are needed to build one from the raw materials - and by raw, I'm talking about ores here, not the refined materials.

I like this one, let's look at it.

A motorbike is basically two things: An internal combustion engine hooked up to a frame that can be comfortably ridden by a passenger.

Let's look at the internal combustion engine first.  The engine exists inside an engine block, which so far as I know is generally cast from a single piece of steel.  Within the engine block you have the cylinders, plus various bearings and shafts and such, plus also O-rings to hold in the pressure.

Most of these are made from various kinds of steel.  I don't know what the particular alloy choices are, and there's definitely going to be a few different ones based on the particular needs for each particular choice.  At a guess there'll also be a bit of Aluminium as a heat transfer element.

I don't claim to know what the "correct" way to do this is, but every motorcycle I can think of runs on a hydrocarbon combined with air.  On Mars, this probably means some kind of synthetic hydrocarbon (perhaps methane) combined with compressed air. 

It's important that it not be just compressed oxygen: The Nitrogen in Earth's atmosphere serves to lower the maximum temperature, which reduces the thermal stress and wear on the combustion cylinders, which otherwise might reach temperatures around (or above) 3000 K.  For reference the maximum service temperature of most steels is below 600 C (the steel can be cooler than the combustion gases but a 2400 K temperature differential is probably impossible).  You might replace compressed air with compressed or liquid oxygen and liquid CO2 as a dilutant.

On this note, it's important to note that there are actually two thermodynamic cycles used in internal combustion engines, the Diesel cycle and the Otto cycle.  The two cycles use somewhat different fuels but the biggest difference is that in the Diesel cycle the heat from compressing the gas causes the fuel to ignite while in the Otto Cycle the ignition source is external, usually spark plugs.  Because the gas is compressed and cold to begin with, this ICE will use the Otto Cycle.  To the best of my knowledge most motorcycles use that anyway.

So you also need spark plugs.  Spark plugs are mostly made from steel and ceramic (usually aluminium oxide), but the sparking elements are usually made from a special alloy designed to withstand particularly high temperatures and the presence of hot oxygen while also being conductive.  For a cheap plug with poor performance and a short lifetime you can use copper, but these days expensive noble metals are used more often.  The actual amount of metal involved is quite small though, in general you can import from Earth (or stockpile in the event of an emergency) or use copper for poor lifetime and performance.

You also need a rubber material (for pressure seals and O-rings) and lubricant.  There's a lot of options.  I talked about it a bit in this thread where I think I settled on silicones for both.  I don't necessarily stand by that but it's certainly an option, along with more traditional polymers and oils like we use on Earth.  It's worth pointing out that polybutadiene (the most common kind of synthetic rubber) can be produced indirectly from ethanol.  It's a little hard to synthesize the long-change hydrocarbons in oils from scratch but it can be done.  You can also get oils from plants (I have a mechanical set of clippers that I lubricate with olive oil--this may not be advisable) but that seems expensive.

The spark plugs are powered by electromagnetic transformers that increase the voltage to enable electric arcing, which presumably are made mostly from copper, iron, and ribber insulation.  In general electrical applications you can replace copper with aluminium for a loss in conductance.

The frame is a bit more amorphous and flexible.  It can be made from any number of materials, generally has rubber tires (but metal frame would work too), usually has some sort of shocks (often containing pneumatics or hydraulics as shocks, but springs would work too).  The engine controls can be purely mechanical if you want them to.

So, as far as base materials go, you need Steel (various alloys, with alloying elements certainly including carbon and perhaps including nickel, manganese, and chromium), perhaps copper, nickel, platinum, or iridium, Alumina, Aluminium, rubber, lubricant, some sort of fuel and oxidizer.

Aluminium comes from Bauxite on Earth, which you get from bodies of water leeching aluminium oxide from the rock and precipitating it elsewhere.  I don't know if there's bauxite on Mars.  It's a good bet that there's probably a passable Aluminium ore--somewhere--but I'm not sure where.

Iron comes from various iron oxide ores.  Average Martian regolith would be considered a low-grade Iron ore on Earth, so it's a good bet that you can find regions with higher, ore-grade purity.  We don't know where though.

Carbon and many rubbers (including polybutadiene) can be produced from derivatives of CO2 and water.

If you can avoid using any special steels (probably at the cost of a shorter component lifetime and worse performance) all you need that's hard to get is a few fractions of a gram of noble metal, plus the (heavy, expensive) equipment to process it down to materials, components, assemblies, and products, and I think you've got yourself a motorcycle.


-Josh

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#61 2018-07-31 02:41:46

Terraformer
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Re: Self-replicating colony - a challenge but how difficult?

Great. Now I wonder how many people would be needed to do all that?

I figure if you can make a motorcycle, you can make most things that we had developed up until maybe the mid 20th century - particularly if you insist that the motorbike have headlights. It seems to me to be a good example of various manufacturing capabilities, since it requires metalworking, chemical engineering for the lubricants and rubber, electrics including batteries and alternators, and the ability to manufacture engines. All stuff that should enable a civilisation to produce trains, planes, washing machines (one of the most important labour saving devices), electro-mechanical computers, refrigerators... if we know how many people are needed to manufacture it, we should have a handle on what the minimum size is for maintaining a steampunk/dieselpunk/atompunk technological civilisation (significantly larger, since we need people to be making food, producing other goods, providing essential services etc).


"I guarantee you that at some point, everything's going to go south on you, and you're going to say, 'This is it, this is how I end.' Now you can either accept that, or you can get to work." - Mark Watney

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#62 2018-07-31 05:59:21

louis
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From: UK
Registered: 2008-03-24
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Re: Self-replicating colony - a challenge but how difficult?

The motorbike is a great example of lack of focus re replication, I would say!

No way would a small colony on Mars start to produce IC engine motorbikes using hydrocarbons. They would stick with electric motors.  It is v. unlikely there would be any replication-related need for electric motorbikes as it would be a cumbersome thing to do - get into a spacesuit and then on to a bike.  I can see there might be something like small electric pressurised quad bikes for exploration purposes. These could be contained within large exploration rovers, so the driver never has to leave a pressurised environment.

IC engines are, incidentally, incredibly complex...in some ways it's amazing they ever won the battle over steam and electric cars, but they did, largely because they had a good, or at least reasonable, balance of range, reliability and simplicity of operation by the driver (no need to stoke up a boiler for instance). I don't think we should assume that a high tech product is always more difficult to produce than some older technologies, and IC engines are probably a classic example of that. To manufacture an IC engine, you need an extremely complex factory, and it isn't really that well suited to small scale production.

High tech products often require incredibly precision at a microscopic level, lab-clean environments and v. pure materials. The Mars colony needs to be able to master these aspects and also be able to manufacture the machines that make the products e.g. the baking ovens for PC panels, the machines that purify silicon based materials etc.

A little video on solar panel manufacture....

https://www.youtube.com/watch?v=qZgWC-Cxd44

Imagine all those processes scaled down to smaller machines - after all, to produce 300 sq metres of panels a week you might be working with only a couple of tonnes of material - maybe 250 kgs for each batch.  I think the human handling could be further reduced with modern robots.

Yes the machines are complex but there is a lot of crossover to other processes with these technologies: furnaces, baking ovens, diamond cutters, wire cutters, thin layer applicators, automated assembly etc.



Terraformer wrote:

Great. Now I wonder how many people would be needed to do all that?

I figure if you can make a motorcycle, you can make most things that we had developed up until maybe the mid 20th century - particularly if you insist that the motorbike have headlights. It seems to me to be a good example of various manufacturing capabilities, since it requires metalworking, chemical engineering for the lubricants and rubber, electrics including batteries and alternators, and the ability to manufacture engines. All stuff that should enable a civilisation to produce trains, planes, washing machines (one of the most important labour saving devices), electro-mechanical computers, refrigerators... if we know how many people are needed to manufacture it, we should have a handle on what the minimum size is for maintaining a steampunk/dieselpunk/atompunk technological civilisation (significantly larger, since we need people to be making food, producing other goods, providing essential services etc).


Let's Go to Mars...Google on: Fast Track to Mars blogspot.com

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#63 2018-07-31 06:32:17

Terraformer
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From: Lancashire
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Re: Self-replicating colony - a challenge but how difficult?

louis,

The point is, if you can't manufacture IC engines, you can't manufacture much beyond 18th century technology. They're not that complex. If you can manufacture motorbikes (which is not to say you *will* manufacture motorbikes), you should be able to have anything we had in the early-mid 20th century.

To manufacture an IC engine, you need an extremely complex factory, and it isn't really that well suited to small scale production.

You've got it the wrong way round. IC engines can be manufacture on the small scale, and often are. It's solar cells that need an expensive and complex factory.


"I guarantee you that at some point, everything's going to go south on you, and you're going to say, 'This is it, this is how I end.' Now you can either accept that, or you can get to work." - Mark Watney

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#64 2018-07-31 11:03:47

JoshNH4H
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Re: Self-replicating colony - a challenge but how difficult?

Terraformer wrote:

washing machines (one of the most important labour saving devices)

Having just moved from an apartment without a washing machine to one with, I could not agree more.

Terraformer wrote:

I figure if you can make a motorcycle, you can make most things that we had developed up until maybe the mid 20th century - particularly if you insist that the motorbike have headlights. It seems to me to be a good example of various manufacturing capabilities, since it requires metalworking, chemical engineering for the lubricants and rubber, electrics including batteries and alternators, and the ability to manufacture engines. All stuff that should enable a civilisation to produce trains, planes, washing machines (one of the most important labour saving devices), electro-mechanical computers, refrigerators... if we know how many people are needed to manufacture it, we should have a handle on what the minimum size is for maintaining a steampunk/dieselpunk/atompunk technological civilisation (significantly larger, since we need people to be making food, producing other goods, providing essential services etc).

I don't buy the absolutist version of this argument, but a more moderate version (automobile/motorcycle technology tracks closely with other important parts of industrial production) seems very defensible.  Consider the following chart, from here:

Automobile-production-various-nations-1900-to-2016-e1497400099939.png

It reflects the global dominance of the US in industrial production through the 60s, the recovery and increasing prosperity of Europe after WWII (they had substantial industrial bases prior to the war but not much of a market for cars), and the growth of Japan and China since then.  Auto production now is roughly 9 times higher than in 1950 while global population has tripled.  The global economy has grown by a factor of ~12 since 1950 (on an inflation-adjusted, PPP basis) as some countries have industrialized while others have transitioned towards a services-based economy.

As far as assessing the required number of people--that seems a bit like a fools errand.  Somewhere between 0 and a few million I suppose, depending on technology, resource availability, and the number of units you need.  There will be economies of scale, naturally, but I'm not sure it's possible to specify a minimum in the abstract.


-Josh

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#65 2018-07-31 11:25:43

kbd512
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Registered: 2015-01-02
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Re: Self-replicating colony - a challenge but how difficult?

The simplest possible type of engine to construct would be the LiquidPiston engine design.  It's basically an inside-out Wankel rotary engine that over-expands the combustion gases to produce more power from the combustion event while lowering temperatures.  A conventional Wankel is the second easiest to produce.  CRE (Ceramic Rotary Engines) has developed a ceramic Wankel to make up for the Wankel's poor thermal efficiency.  The lightest engines, but most expensive and complex to manufacture, would be the high temperature plastic conventional piston engines that uses metallic cylinder liners for the parts that contain the combustion event.  A conventional piston engine is the most complicated and expensive to manufacture, if cheaper in large production quantities that a Mars colony would never see.

Mazda Wankels for racing applications are made from A356 Aluminum alloy cast or billet plates for the rotors and intake housings.  The rotors have been made from Aluminum with electro-spray coatings, various Titanium alloys (mostly a failure), and various conventional piston steels.

Popular Construction Materials for Engines...

Aluminum Alloys:
A356 and AA242 - aviation engines (castings for block/crankcase and cylinder heads)
A319 and A380 - automotive engines (castings for block and cylinder heads)
2618 and 4032 - piston forgings

Steel Alloys:
8620 and 4340 (crankshafts and connecting rods)
9310 is pretty popular for (high performance gears)

Other Non-Ferrous Bearing Alloys:
wide variety of Lead / Tin / Zinc / Copper alloys (bearings)

Gasket and Seal Materials:
silicone or viton are popular (high performance gasket materials)

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#66 2018-07-31 13:14:00

louis
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From: UK
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Re: Self-replicating colony - a challenge but how difficult?

But why make that the test for self-replication? Achieving a random early 20th century technology level is not going to get you to self-replication.  Early 20th century technology was highly dependent on energy systems based on hydrocarbons or hydroelectric systems, neither of which are a good fit for Mars. PV or nuclear power are the best fit. So, for me that is the first test - can you reproduce such energy systems within your colony on Mars? 

Terraformer wrote:

louis,

The point is, if you can't manufacture IC engines, you can't manufacture much beyond 18th century technology. They're not that complex. If you can manufacture motorbikes (which is not to say you *will* manufacture motorbikes), you should be able to have anything we had in the early-mid 20th century.

To manufacture an IC engine, you need an extremely complex factory, and it isn't really that well suited to small scale production.

You've got it the wrong way round. IC engines can be manufacture on the small scale, and often are. It's solar cells that need an expensive and complex factory.


Let's Go to Mars...Google on: Fast Track to Mars blogspot.com

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#67 2018-07-31 14:06:57

JoshNH4H
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Re: Self-replicating colony - a challenge but how difficult?

Hey louis,

Would you be able to craft, in this thread, an end-to-end (ore to installation) specific, usable series of procedures for the construction of a solar cell?  How about a lithium ion battery?  How widely applicable is each step of this process to other necessary activities which will be undertaken in the settlement?

These are high technology items that require high precision and lots of specific steps to produce.  Nobody has claimed that they have no place on Mars.  Nobody has even claimed that internal combustion engines necessarily do have a place on Mars (although for applications requiring long range and long power-to-weight they are an attractive option). 

The claim, rather, was that the ability to build such a thing focuses our thoughts upon a number of critical technologies, from the mining and processing of critical economic ores, fine and bulk metal forming (which is fundamentally necessary for a broad range of applications, including transportation but also including the construction of any pressure vessel (this means habitats too), in virtually every kind of engineering design and application).  Incidentally, internal combustion engines usually exist in conjunction with smaller rechargeable batteries and electric motors, which are required to start the engine initially.  On Earth typically these are lead-acid batteries, but it might not make sense to produce many different kinds of rechargeable battery.


-Josh

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#68 2018-07-31 15:15:05

Terraformer
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Re: Self-replicating colony - a challenge but how difficult?

Well, if they have access to lots of copper and plenty of space, they could use Copper Oxide solar cells. Unfortunately, the efficiency is only around 1%, so the EROI will be far below 1 on Mars.


"I guarantee you that at some point, everything's going to go south on you, and you're going to say, 'This is it, this is how I end.' Now you can either accept that, or you can get to work." - Mark Watney

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#69 2018-07-31 16:03:15

JoshNH4H
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Re: Self-replicating colony - a challenge but how difficult?

There's always the mechanical alternative to photovoltaic cells, which is the solar power tower.  I think it has a lot of potential anyway, even on Earth.  The existence of CSP technology basically means that PV is not strictly necessary to be able to generate solar power at all, because in a pinch you can build a system that performs a similar function using other, simpler technologies that will find more widespread use.  A nice bonus to solar power towers is that you can produce molten salts as a heat reservoir to generate energy at night.  This increases your efficiency because you don't have to put the energy in to create a battery, and you don't have to convert to chemical and then back to electrical energy.  Plus, a substantial portion of energy consumption is thermal anyway.


-Josh

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#70 2018-07-31 17:34:49

louis
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From: UK
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Re: Self-replicating colony - a challenge but how difficult?

I have posted a video showing the process - but obviously that is just the briefest of overviews.  If I were to post everything you needed to do - in terms of mining, purification, adding chemicals, making the machines, and then operating the machines, obviously I would be posting thousands of pages of patents, instructions and chemical formulae. Even then, you still need trained personnel to supervise some of the key processes. But I would still maintain that making a PV panel is a lot simpler than putting together an IC engine vehicle. An ordinary family car often has 40,000 parts each without its own complex manufacture process. How many parts does a PV panel have?  It looks about 10 or so.  The control  systems and cabling will add complexity of course. What is difficult in PV panel manufacture is the precision processes and the clean environment requirements. 

Here are the basic step processes - if you tried something for an IC engine vehicle there would be thousands of steps:

https://www.greenmatch.co.uk/blog/2014/ … anels-made

For self-replication you always need to apply the KISS principle. So electric motors not internal combustion engines. So 1000 basic glass receptacle designs, not 1 million as on Earth.  So forget our addiction to paper. 

If you have a laser focus on colony self-replication I think you could do it with as few as 1000 people. 

Some arbitrary figures:

100 people working on energy - producing the 300 sq. metres of PV panelling per week and installing/maintaining all energy systems.

150 people working on agriculture and food processing. They feed themselves and the other 800 people in the colony and accumulate strategic food stocks.

50 people working on life support - ensuring air supply, pressurisation, clean water, heat and hot water, hygiene services etc.

100 people working in general manufacturing - producing, amongst other things, bricks, air locks, cement, concrete, basalt tiles, sealants, fittings for habs (kitchen, bathroom and living area fittings), computer components, computers, agricultural equipment, transport vehicles,  electric cabling and control equipment, gas cylinders, plumbing systems, water recycling facilities, textiles (clothing etc), EVA suits, sports and gym equipment etc

50 people working in admin and planning - ensuring everything is working in a co-ordinated fashion.

50 people working in mining - supervising robot miners, prospecting etc.

75 people working in metallurgy, producing high grade steel in various forms (sheet, rods etc) and other metal products as well.

75 people working in chemicals - producing liquid, gas and solid chemicals for use in industry.

75 people working in plastics and ceramics

75 people working in construction.

50 working in robotics, machine tools, 3D printers and other machinery production

50 people working in transportation.

50 people working in health (including procreation and maternity services)

50 in miscellaneous including retail, catering etc.

This would be a v. robotised environment where robots cleaned floors, walls, windows and PV panels. Where robots prepared meals and sandwiches. Where robots supplied most of the industrial labour force. Where robots did much of the agricultural work.





JoshNH4H wrote:

Hey louis,

Would you be able to craft, in this thread, an end-to-end (ore to installation) specific, usable series of procedures for the construction of a solar cell?  How about a lithium ion battery?  How widely applicable is each step of this process to other necessary activities which will be undertaken in the settlement?

These are high technology items that require high precision and lots of specific steps to produce.  Nobody has claimed that they have no place on Mars.  Nobody has even claimed that internal combustion engines necessarily do have a place on Mars (although for applications requiring long range and long power-to-weight they are an attractive option). 

The claim, rather, was that the ability to build such a thing focuses our thoughts upon a number of critical technologies, from the mining and processing of critical economic ores, fine and bulk metal forming (which is fundamentally necessary for a broad range of applications, including transportation but also including the construction of any pressure vessel (this means habitats too), in virtually every kind of engineering design and application).  Incidentally, internal combustion engines usually exist in conjunction with smaller rechargeable batteries and electric motors, which are required to start the engine initially.  On Earth typically these are lead-acid batteries, but it might not make sense to produce many different kinds of rechargeable battery.


Let's Go to Mars...Google on: Fast Track to Mars blogspot.com

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#71 2018-07-31 22:30:33

JoshNH4H
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Re: Self-replicating colony - a challenge but how difficult?

louis wrote:

If I were to post everything you needed to do - in terms of mining, purification, adding chemicals, making the machines, and then operating the machines, obviously I would be posting thousands of pages of patents, instructions and chemical formulae. Even then, you still need trained personnel to supervise some of the key processes. But I would still maintain that making a PV panel is a lot simpler than putting together an IC engine vehicle. An ordinary family car often has 40,000 parts each without its own complex manufacture process. How many parts does a PV panel have?  It looks about 10 or so.  The control  systems and cabling will add complexity of course. What is difficult in PV panel manufacture is the precision processes and the clean environment requirements.

That basic overview doesn't describe the actual difficulty of any of those steps.  Precision is hard, and virtually always involves human hands.  You don't just say "I'm going to be precise" and then do it.  You need labor and machines to make it happen and lots of both.  And the more precise your machines are the harder it is to automate.  And you can't afford to sacrifice precision, in this case, without your efficiency declining by perhaps an order of magnitude. 

The thing about an ICE is that you could make most of the parts in a machine shop (or a CNC) if you really had to, and not a particularly well-outfitted one at that.  Your estimate of parts is wrong (more accurately, it's irrelevant--consumer vehicles contain various systems and parts that add convenience or performance without greatly affecting the fundamental function of the thing itself).

The key to self-replication is not number of parts, per se, it's commonality of parts.  If you have a machine that requires 10,000 of a single part, that's infinitely easier to replicate than 10,000 (or 5,000, or 1,000, or 100) different kinds of part where you only need one of each.  The physical and chemical processes involved in making PV panels are varied, unique, and hard to set up, and you've made it clear that you intend to take this for granted...

louis wrote:

High tech products often require incredibly precision at a microscopic level, lab-clean environments and v. pure materials. The Mars colony needs to be able to master these aspects and also be able to manufacture the machines that make the products e.g. the baking ovens for PC panels, the machines that purify silicon based materials etc.

...in a way that I would say does not make sense.  There's simply no reason for the colony to master these technologies unless they have to, and they don't have to.  Or at least, they don't have to.  As I mentioned above, solar power towers have comparable or superior efficiency while being manufacturable with the same metal-forming technologies that really are foundational to any industrial society.  I would argue that if self-replication is your goal you're best off without, and instead focusing on reducing the number of different kinds of process.

Finally:

louis wrote:

If you have a laser focus on colony self-replication I think you could do it with as few as 1000 people.

Some arbitrary figures:

100 people working on energy - producing the 300 sq. metres of PV panelling per week and installing/maintaining all energy systems.

150 people working on agriculture and food processing. They feed themselves and the other 800 people in the colony and accumulate strategic food stocks.

50 people working on life support - ensuring air supply, pressurisation, clean water, heat and hot water, hygiene services etc.

100 people working in general manufacturing - producing, amongst other things, bricks, air locks, cement, concrete, basalt tiles, sealants, fittings for habs (kitchen, bathroom and living area fittings), computer components, computers, agricultural equipment, transport vehicles,  electric cabling and control equipment, gas cylinders, plumbing systems, water recycling facilities, textiles (clothing etc), EVA suits, sports and gym equipment etc

50 people working in admin and planning - ensuring everything is working in a co-ordinated fashion.

50 people working in mining - supervising robot miners, prospecting etc.

75 people working in metallurgy, producing high grade steel in various forms (sheet, rods etc) and other metal products as well.

75 people working in chemicals - producing liquid, gas and solid chemicals for use in industry.

75 people working in plastics and ceramics

75 people working in construction.

50 working in robotics, machine tools, 3D printers and other machinery production

50 people working in transportation.

50 people working in health (including procreation and maternity services)

50 in miscellaneous including retail, catering etc.

This would be a v. robotised environment where robots cleaned floors, walls, windows and PV panels. Where robots prepared meals and sandwiches. Where robots supplied most of the industrial labour force. Where robots did much of the agricultural work.

What value do these "arbitrary figures" have?


-Josh

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#72 2018-08-01 00:12:12

Oldfart1939
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Registered: 2016-11-26
Posts: 1,548

Re: Self-replicating colony - a challenge but how difficult?

I really haven't chimed in on this thread, since I find it to be similar to the "Angels dancing on the head of a pin" style of discourse. I somewhat more crudely call it a fruitless form of mental masturbation.

Now for my real comments: Some of the basic assumptions here are too arbitrary. It totally assumes the colony will be based around use of solar power, and too much of the manufacturing is geared towards replication of solar panels. There hasn't been anywhere near enough concentration on the development of the underlying chemical industry required for a lot of these phantom industries to get started--much less flourish. Everything manufactured from Mars ISRU requires metallurgical extraction or purification of substances extracted from regolith and/or the atmosphere. Until this happens, none of the other associated "industries" have a chance in Hell of working. Everything stated is far more power intensive than a solar farm can provide. Period.

Last edited by Oldfart1939 (2018-08-01 00:16:27)

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#73 2018-08-01 03:34:35

Terraformer
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Re: Self-replicating colony - a challenge but how difficult?

I really haven't chimed in on this thread, since I find it to be similar to the "Angels dancing on the head of a pin" style of discourse. I somewhat more crudely call it a fruitless form of mental masturbation.

I think that's an unfair comparison. Thinking about what would be needed for self-replication actually has a use, since it helps us figure out what early colonies can make for themselves and what would be better off imported, as well as the enabling technologies they'd need.


"I guarantee you that at some point, everything's going to go south on you, and you're going to say, 'This is it, this is how I end.' Now you can either accept that, or you can get to work." - Mark Watney

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#74 2018-08-01 06:54:10

louis
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From: UK
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Re: Self-replicating colony - a challenge but how difficult?

JoshNH4H wrote:

That basic overview doesn't describe the actual difficulty of any of those steps.  Precision is hard, and virtually always involves human hands.  You don't just say "I'm going to be precise" and then do it.  You need labor and machines to make it happen and lots of both.  And the more precise your machines are the harder it is to automate.  And you can't afford to sacrifice precision, in this case, without your efficiency declining by perhaps an order of magnitude. 

The thing about an ICE is that you could make most of the parts in a machine shop (or a CNC) if you really had to, and not a particularly well-outfitted one at that.  Your estimate of parts is wrong (more accurately, it's irrelevant--consumer vehicles contain various systems and parts that add convenience or performance without greatly affecting the fundamental function of the thing itself).

The key to self-replication is not number of parts, per se, it's commonality of parts.  If you have a machine that requires 10,000 of a single part, that's infinitely easier to replicate than 10,000 (or 5,000, or 1,000, or 100) different kinds of part where you only need one of each.  The physical and chemical processes involved in making PV panels are varied, unique, and hard to set up, and you've made it clear that you intend to take this for granted...

Same applies to PV Panel manufacture - you could make the parts in a machine shop. You can do it at home...if your home has the right chemicals:

https://www.youtube.com/watch?v=8DQt8Sd1qgY

In a small colony (and I think that is an assumption here is it not? - if Mars had tens of millions of people, self-replication would be no more difficult than on Earth, I would say) it is important to avoid manufacturing processes that involve thousands of parts, as far as possible and, yes, commonality is important. In an SR Mars I think robotics is vitally important. Industrial robot arms are essentially the same whatever the application, varying only in size and manipulation (e.g. suction pads or grips or drills, or whatever).
.

...in a way that I would say does not make sense.  There's simply no reason for the colony to master these technologies unless they have to, and they don't have to.  Or at least, they don't have to.  As I mentioned above, solar power towers have comparable or superior efficiency while being manufacturable with the same metal-forming technologies that really are foundational to any industrial society.  I would argue that if self-replication is your goal you're best off without, and instead focusing on reducing the number of different kinds of process.

I think for a small colony to successfully self-replicate, they need hi-tech precision industry, robotics, and an advanced chemicals industry.

What value do these "arbitrary figures" have?

I think the value is as part of the overall thought experiment - how low can you go.  They aren't completely arbitrary.  I've indicated that a colony of 1000 might need to produce 300 sq. metres of PV panelling per week.  They'll also need to maintain a huge solar array of 300,000 sq. metres and all the electrical cabling and control equipment around the colony.  An allocation of 100 people would certainly cover all that I feel. It might be over-generous.


Let's Go to Mars...Google on: Fast Track to Mars blogspot.com

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#75 2018-08-01 07:18:05

louis
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From: UK
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Re: Self-replicating colony - a challenge but how difficult?

I call it a thought experiment. Thought experiments often help shine a light on issues. You are free to argue that nuclear power makes it easier to achieve self-replication. I've no problem with that, although I doubt it.

I agree the chemical industry is vital.  You need probably nearly the full range of gases and chemicals produced on Earth, but obviously in much smaller quantities if we are talking about a small colony of 1000 people.   I was reading that sulphuric acid is the leading industrial chemical. On Earth we produce something like 100 million tonnes per annum.  Proportionately for a colony of 1000 (assuming Earth's population is about 7 billion) that would mean on Mars we would need a maximum of just over 14 tonnes per annum or about 39 kgs per sol. I say maximum but given the nature of a self-replicating colony on Mars the true figure might be much lower.

In a small colony you'd probably produce these chemicals in batches. So maybe you'd maybe make 400 kgs of sulphuric acid every 10 days. Less common chemicals might be produced every 100 days and so on...you'd be working to a detailed schedule of production.


Oldfart1939 wrote:

I really haven't chimed in on this thread, since I find it to be similar to the "Angels dancing on the head of a pin" style of discourse. I somewhat more crudely call it a fruitless form of mental masturbation.

Now for my real comments: Some of the basic assumptions here are too arbitrary. It totally assumes the colony will be based around use of solar power, and too much of the manufacturing is geared towards replication of solar panels. There hasn't been anywhere near enough concentration on the development of the underlying chemical industry required for a lot of these phantom industries to get started--much less flourish. Everything manufactured from Mars ISRU requires metallurgical extraction or purification of substances extracted from regolith and/or the atmosphere. Until this happens, none of the other associated "industries" have a chance in Hell of working. Everything stated is far more power intensive than a solar farm can provide. Period.


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