The prospects of colonizing Mars

  • Once in a while H-G has a sense of humor, so that rules out his being a bot. :) That said, he could be more constructive than he is. To his credit, he does contribute something of interest on occasion.


    No joke:


    Reality based pessimism can be a constructive counterweight to unrealistic optimism.


    Example:


    We can never be prosperous and happy on Mars. Let us take care of our one and only Earth instead.

  • Reality based pessimism can be a constructive counterweight to unrealistic optimism.


    Example:


    We can never be prosperous and happy on Mars.


    That is not reality based. That is opinionated speculation with no technical basis. There is no reason to think people can never be prosperous and happy on Mars. That is like saying airplanes will never carry more than 20 passengers or fly faster than 200 mph, which is what some people said well into the 1920s. It is not unrealistic optimism to think that 100 or 200 years from now, millions of people might be living happily on Mars, and there is no doubt whatever that there is abundant wealth on Mars. There is abundant wealth anywhere in the solar system for people capable of colonizing Mars. People who can master that technology could, for example, convert the Sahara desert into forest, farmlands and gardens.

  • Jed, as you know, there is little water and no air on Mars. There is reduced atmospheric pressure, and high radiation levels. What resources are worth that? Sure with enough money and technology you might be able to eke out survival in 100+ years from now. Any idea where the energy for it would come from? Suppose LENR isn't proven practical by then, how do you take materials for a fission power plant to Mars? The sun's light is much reduced from Earth's levels so photoelectricity is low yield. Anything is possible but this seems unlikely. The Earth's worst desert is infinitely more hospitable. Also this is OTC-- maybe move this to Playground thread?

  • Jed, as you know, there is little water and no air on Mars.


    That's like saying there is no air on the moon. (The crust of the moon is 42% SiO2 and 14% Al2O3.) You will note, there is more water orbiting Saturn than there is in all the oceans of earth. I don't suppose people would want to transfer all of that to Mars. It would be a shame to destroy the rings. But there is plenty more water elsewhere in the solar system. Comets are mainly water and their total mass is ~2% of solar mass, which is to say ~6,700 times more than the mass of the earth. So, we are not running out of water anytime soon, are we?



    What resources are worth that?


    Every planet is loaded with millions of times more resources than the human race will consume before the sun goes out. It is just a matter of extracting it. A cubic kilometer of ordinary rock or ocean water has enough of many elements to supply the human race for hundreds of years. A 318-year supply of Mg, for example. Resources are not "worth" some fixed amount of money. The cost of any resource is purely a function of human intelligence and technology.



    Sure with enough money and technology you might be able to eke out survival in 100+ years from now.


    With enough money and technology you could provide every person on Mars and Earth ten times more material resources than they now have, or a hundred times, with practically no pollution. The material resources of the solar system are millions of times greater than those of earth, and many of them are easier to extract without causing pollution or taking up land.



    Any idea where the energy for it would come from?


    Fission, fusion, cold fusion or solar energy. The sun produces 2.8 * 10^26 W, enough energy to provide every person now alive with 4,000 times more energy than the entire human race consumes. As Arthur Clarke put it, energy is the most abundant resource in the universe.


    Getting back to my earlier comment, my point was that the kind of people who are willing to uproot themselves, face the challenge and go to Mars will prosper because they will have guts and they will face challenges. They will develop the technology to extract resources more readily than the soft-living, stay-at-home people on earth. They will be better at space-faring, meaning they will have cheaper access to the comets and asteroids, giving them millions of times more resources than people on earth can mine or extract from sea water. So in a few hundred years, they will be the best educated, wealthiest people with the best technology. This is what happened to Europeans who came to North America in the 17th and 18th centuries.

  • @Jed Rothwell


    Your argument about resources is that they are there and all that matters is the total mass? How diffusely the resource is distributed and how difficult it is to extract, purify or prepare for use doesn't matter? OK. So I know this little planet in Alpha Centauri only 4 light years from here. Not only does it have tons of frozen Helium-3 laying around all over (the natives will pay you to truck it away because it gums up the treads on their ice tractors) but they also have a charming Star Wars-style cantina where all the miners go to relax (supply your own weapons). All you have to do is rocket over to get the stuff and bring it here and you will be rich beyond your dreams.


    As to when we can travel to Mars with enough resources for even a short stay on surface and a reasonable chance of returning, that is not too far. Thing is, the Human Race may not make it even to that because of all the bickering over land and government and religion. And everyone, good or bad, is getting better and better weapons with fewer and fewer safeguards, That is what to worry about right now, not terraforming a planet and moving it to a lower orbit where it can get adequate sunlight. Sure, maybe some day, but not "soon". That ever evasive "soon."

  • Before asking if we should colonize Mars we had better ask if it is at all possible. Mars colonization comes in two distinct flavors: Earth-sustained and Mars-sustained.


    There is little doubt that a Mars colony continuously supported from Earth is possible. The cost of this support will be very high though, thereby severely limiting the size of the colony. But this is not the type of colony that people are most interested in; the Mars colony should be self-sustaining. Elon Musk, the most outspoken proponent for a self-sustaining Mars colony estimates that it would take at least a million humans to realize this goal. Let us assume that this is correct. So when the Mars population is only half a million, what will be the cost of keeping them alive with supplies from earth and what entities are willing to pay for them?


    An even bigger problem is how to make ends meet for the Mars economy. In order to produce resources you need other resources. Here on Earth most of the basic resources are free and easily accessible, on Mars they are not. The resources needed on Mars to just stay alive come from the top of our technological food chain. Just imagine the network of industries, machinery and skills it takes to produce a space suit. Now, try to imagine that to be constructed on Mars. How many space suits will be worn out in the process?


    Besides, the best reason for a Mars colony seems to be to have a backup for humanity. At first sight it may seem logical to extrapolate the personal survival instinct to the whole of humanity. But on second thought, if humanity succumbs who is there to be sorry?

  • Your argument about resources is that they are there and all that matters is the total mass? How diffusely the resource is distributed and how difficult it is to extract, purify or prepare for use doesn't matter?

    It would not matter with space based industry and solar power. As I said, the sun produces 2.8 * 10^26 W. You could vaporize the entire Earth in about a day with that. However diffuse the resources are, they could be mined and concentrated with that kind of energy source. However, in fact, ores and other resources in asteroids are more concentrated and easier to get to than on earth. The oxygen and aluminum on the surface of the moon is right there in the crust. There is probably helium-3 as well, in enough abundance to supply reactors on Earth, Mars and elsewhere for centuries. So even if cold fusion does not work, your earlier comment about having to supply uranium from earth is wrong. I do not know whether there is uranium on Mars, but helium-3 from the moon might be a better choice. It is even possible the plasma fusion program will make progress in the next 200 years, although I would not bet on it.


    Let me list a few technologies that would make this easier and more likely to happen.


    With a space elevator, improved robots and improved interplanetary rockets, we could send goods to Mars cheaper than we now send them from Beijing to New York, in about the same amount of time: a few weeks. Ed Storms and others at LANL made progress on a fission rocket that could do that. That may not be practical but one with cold fusion or helium-3 might be. We could also bring back asteroids with a 100-year supply of gold, platinum, nickel and -- of course -- iron, and sell it far cheaper than any mine on earth. We could bring it to Earth or Mars or anywhere else.


    Self-replicating robots are essential to any planetary scale project, such as terraforming Mars to allow millions of people to live there comfortably. These were described by von Neumann in Theory of Self-Reproducing Automata. Suppose you manufactured self-replicating robots in space, in a place with unlimited raw materials and energy. (Solar or nuclear energy.) One robot makes 2, 2 make 4, and in a short time you have billions or trillions of them. As many as you need. Such robots could spread out over Mars and terraform it in about the same time it took rabbits to spread out over Australia. This not an analogy; it is close comparison. Rabbits are self-replicating robots that reproduce and sustain themselves from resources taken from the surroundings. The robots might construct space ships which go to comets, break them into small pieces, and send them on an orbit to intercept Mars. After a few years they would begin to enter the thin Martian atmosphere, and melt or vaporize. It would begin to rain. After billions of them impact, there would be lakes and eventually oceans. Some of the water could be fractured and the hydrogen disposed of (perhaps dumped into the sun) to produce an oxygen atmosphere.


    There is no reason why this could not be done with self-replicating robots. After you develop and program the robots, the cost would be zero. It would not use resources from Earth. There are lots of resources elsewhere. For example, suppose you wanted to make them out of plastic hydrocarbons. I do not know where the carbon might come from -- perhaps the atmosphere of Mars, which is mostly CO2 -- but there is quite a lot of hydrogen in various places such as Jupiter. About 310 times the mass of the Earth. That is enough to make many, many robots. As I said, we are not running out of resources.


    To extract the C from CO2 on Mars you might need a few trillion self-replicating robots with built-in chemical separation equipment. That is also how you would remove excess C from Earth's atmosphere. We already have such self-replicating robots: they are called plants. We might need a non-living version. The cost, as I said, would be zero. You plant some "seeds" (organic or robotic), wait a few generations and the whole planet is covered with them.


    After self-replicating robots are developed for several thousand years, you could build a structure on any scale with them. Even a Dyson sphere.


    Arthur Clarke described this in Profiles of the Future, chapter 12 "Ages of Plenty." Regarding energy, he wrote:


    "For terrestrial projects, it does not greatly matter whether or not the universe contains unknown and un­tapped energy sources. The heavy hydrogen in the seas can drive all our machines, heat all our cities, for as far ahead as we can imagine. If, as is perfectly pos­sible, we are short of energy two generations from now, it will be through our own incompetence. We will be like Stone age men freezing to death on top of a coal bed."


    He concluded the chapter:


    "This survey should be enough to indicate—though not to prove—that there need never be any permanent shortage of raw materials. Yet Sir George Darwin's prediction (page 85) that ours would be a golden age compared with the aeons of poverty to follow, may well be perfectly correct. In this inconceivably enormous uni­verse, we can never run out of energy or matter. But we can all too easily run out of brains."


    http://www.lenr-canr.org/acrobat/RothwellJreviewofpr.pdf



    But this is not the type of colony that people are most interested in; the Mars colony should be self-sustaining.


    Why would it not be self sustaining? I do not understand this comment. Why would it be any different from people sustaining themselves on earth? Of course they would have to extract air and build much stronger houses and cities, but there is no question it can be done. With enough robots it would not cost much. There are enough resources on Mars and in asteroids to sustain billions of people for the remaining lifetime of the sun. As I said, these people would be good at space-faring and extracting resources from asteroids.


    That is what to worry about right now, not terraforming a planet and moving it to a lower orbit where it can get adequate sunlight.

    If the sunlight is not adequate, it could be augmented with large mirrors made of Mylar or PET. This would be easier than moving the planet to a lower orbit. See:


    https://en.wikipedia.org/wiki/…rs#Use_of_orbital_mirrors


    Please do not ask "where would the materials come from?" We have been over that. PET is made from C, O and H. There is enough of those materials on Mars to make as many mirrors as you need. You could bring the material off the planet with a space elevator, and yes, you could build one even though it would extend beyond Phobos.


    This is science fiction, but I have not listed a single thing which is impossible. Intelligent, self replicating robots in particular are not only possible, they are common. Everywhere! Look in the mirror and you will see one. It will not be long before an AI machine based version becomes possible.

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    With a space elevator

    OK, that's where I stop discussing this with you. That is a completely insane idea, at least for centuries to come if not permanently.


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    Rabbits are self-replicating robots that reproduce and sustain themselves from resources taken from the surroundings. The robots might construct space ships which go to comets, break them into small pieces, and send them on an orbit to intercept Mars.

    But I do like the idea of bunnies taking over. Beware of Evil Bunnies though.

  • OK, that's where I stop discussing this with you. That [space elevator] is a completely insane idea, at least for centuries to come if not permanently.

    Again, you have dismissed an idea without first learning about it. NASA and the IAA are making good progress in space elevators. Rapid progress is being made in mono-filament materials. Material strong enough for an elevator might be made within 10 years. That would be the key breakthrough. The other parts of the technology are already possible. The IAA hopes to make an elevator by 2035. See:


    https://www.extremetech.com/ex…lt-by-2035-says-new-study


    https://sservi.nasa.gov/articles/the-space-elevator-concept/


    http://www.niac.usra.edu/files…nal_report/472Edwards.pdf


    You should not dismiss serious proposals made by experts as "insane." This is the kind willful ignorance that makes people dismiss cold fusion. If you have not read the literature carefully, you don't know, and you cannot judge.

  • OK. So I know this little planet in Alpha Centauri only 4 light years from here.

    There is probably abundant helium-3 on the Moon and even more on Jupiter. The Moon is 1.3 light seconds away, 97,000,000 times closer than Alpha Centauri. (As long as we are being flippant.)


    You do not seem to understand that abundant resources are available all over the solar system. Just because it would be difficult to live on the Moon or Mars, that does not mean it would be a hardscrabble existence, or that people living there would be poor. It would not mean they need help from Earth a generation after they settle in and build factories and chemical plants. It would resemble living in Saudi Arabia. The climate is fierce but they would be sitting on top of tremendous mineral wealth, completely untapped, with no restrictions for mining, property owners or ecology to worry about, and with enough energy (from the sun plus large mirrors) to slowly vaporize the planet if they wanted to.


    With unlimited amounts of zero cost energy, you can "extract, purify or prepare for use" material no matter how diffuse it is. The concept of "pay dirt" becomes meaningless. You could extract gold from your back yard at a profit. Ore at 1 PPM is is just as valuable as 1 PPT. It just means the furnaces or mirrors are bigger and use more energy, and the robots produce a thousand times more slag, which you leave in orbit where you found it, or you dump into the sun, or use for ballast in a space elevator. With enough energy, the hardest granite can be crushed or vaporized at no cost. Granite contains lots of gold, uranium and so on. Enough uranium to produce all the energy you need to crush it.


    However, as I said, metals are more concentrated in asteroids than they are in mines on Earth. Not less. I don't know about the concentration of ore on Mars, but any group of people with the skills to colonize Mars will have no difficulty gathering and processing asteroids. They will sell gold, nickel, platinum, and steel to the Earth at prices far below Earth mines. They will be the wealthiest people with the best technology and the most advanced universities. Not despite the fact they live in an unforgiving place that calls for vigilance and the best skills they can muster to survive, but because of that.

  • Sticking to Mars for a moment because it's "easy:"


    Quote

    Mars’ Atmosphere:

    Mars has a very thin atmosphere which is composed of 96% carbon dioxide, 1.93% argon and 1.89% nitrogen, along with traces of oxygen and water. The atmosphere is quite dusty, containing particulates that measure 1.5 micrometers in diameter, which is what gives the Martian sky its tawny color when seen from the surface. Mars’ atmospheric pressure ranges from 0.4 to 0.87 kPa, which is the equivalent of about 1% of Earth’s at sea level.


    More depressing details at: https://en.wikipedia.org/wiki/Climate_of_Mars And that is before we get to radiation, solar flares, and more.

    When you go to settle down there, Jed, be sure to save me some fish.

  • More depressing details at: https://en.wikipedia.org/wiki/Climate_of_Mars And that is before we get to radiation, solar flares, and more.

    Obviously people will have to build well-shielded structures and caves, and live indoors at first. Probably for decades or hundreds of years. Perhaps it can be terraformed centuries from now enough that people can go outside. I wouldn't know about that.


    It is only depressing if you don't live there. Most people who live in the arctic are not depressed by the extreme cold, even though it will kill you in a half hour if you are exposed to it without protective clothing. People who live in noisy, crowded, polluted cities take it in stride, and many would not live anywhere else. As they say in Japanese, "if you live there, it's a palace." (Sumeba miyako da.)

  • I believe NASA and others overestimate the hurdles of living in space or, for instance, Mars. Elon Musk's Tesla went to space and was filmed there for several days and, after that, looked pretty OK. If one would consider what NASA and others say, they would think that the Tesla would be completely destroyed by the heat when exposed to the Sun or by the cold when in darkness. And I even not mentioned the vacuum of space.

    I believe humans would do just fine in Mars with current technology and resources.

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    As for ores on Mars, I have no idea except to say that the first astronauts to arrive will feel the need to find some.

    Right. Just as soon as they get done finding air (oxygen), water, radiation shielding, energy and food. And I bet it will be difficult to find good household help, good TV repair people, and In and Out burgers for quite some time.





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    Elon Musk's Tesla went to space and was filmed there for several days and, after that, looked pretty OK.

    I believe humans would do just fine in Mars with current technology and resources.


    Sure. As long as people can be made of metal and glass and can run on rechargeable lithium ion batteries! :-)

  • I think we are missing something here. Allowing myself a slight deviation from the subject of this thread I would like to ask: What would be the purpose of colonizing Mars apart from having an (unnecessary) backup for humankind?


    Why would we want to live on Mars? The key word here is "live". Then why do we want to live? In order to die and go to heaven living happily there forever? No, that is just superstition.


    We want to live because it is programmed into our genes from the very beginning when the first cell embarked on a billion years time trip. Along the road its descendants have terraformed Earth and branched into the wonderful web of life that surrounds our unique spaceship. The purpose of life is life itself and an integral part of living is being part of this web.


    The idea to try to bring a part of the web of life to a dead, inhospitable (to say the very least) heavenly body is totally pointless, not to say bizarre. Living there will be a lifelong depression where the final decomposition in the LENR-driven atomic recycler will come as a liberation. When we finally have cured death you will have to take resort to the Black Pill in order to escape the hell on Mars or whatever hell you are stuck in. (Unless you can afford a return ticket to Earth on one of Elons BFR:s, of course.)


    If somebody needs a reminder of what you would leave behind I recommend enjoying the BBC series BLUE PLANET II:

    http://www.bbcearth.com/blueplanet2/

    Don't forget to bring it on a USB stick when you go to Mars!


    If this won't make you homesick bring these too:

    Blue Planet: https://www.imdb.com/title/tt0296310/

    https://shop.bbc.com/planet-ea…ft-set-blu-ray-21017.html


    Oh, and this is a must too:



    Since bird spotting on Mars will be a frustrating undertaking do not forget this one:

    The Best Moments from Earthflight (Winged Planet)



  • In the unlikely event of my being offered passage to Mars I would go, even if I never came back. It would certainly save my family the cost of a funeral. However, time-lag on data communication would make moderation difficult.

  • Sure. As long as people can be made of metal and glass and can run on rechargeable lithium ion batteries!

    People have lived in the International Space Station for years without ill effects. It will be much easier to build a shielded, protected environment on Mars than in a thin, small, low orbit vehicle such as the Space Station.

  • What would be the purpose of colonizing Mars apart from having an (unnecessary) backup for humankind?

    The purpose would be exactly the same as it was when ancient people left warm, comfortable Africa and Southern Europe and migrated to the north, where they had to wear heavy clothing and learn to survive in ways that no primate could without tools, furs and hunting animals that no primate could possible kill without complicated weapons, coordination and knowlege. If you don't think it was complicated, you don't know much about ancient hunters. It was the same as when ancient people crossed over to North American, built boats and went to Japan, and then fanned out over the Pacific to the islands and Australia. It was what drove my ancestors from comfortable, wealthy England to the middle of nowhere in Canada. People have a deep urge to explore and to go where there is nothing, and where life is challenging, and where they have to start over with nothing.


    When you go to inhospitable places that happen to have far more wealth and potential than the old country you come from, a few generations later your descendants are wealthy, educated and skilled in ways they never would have been if you had stayed home.


    Mars and the asteroids are empty worlds that have millions of times more material wealth than earth. I mean that literally. Millions of times more iron, gold, silicon, energy and everything else. There for the taking. No one owns it. No one can stop you from mining it, and there are no energy limits or worries about pollution. With self-replicating robots the cost of taking it will be zero dollars. You need only a few things to master these new worlds: intelligence and hard work. You do not need to seize the land from Native Americans the way my ancestors did, or destroy the ecosystem, or suffer from starvation or disease. You can live comfortably, although it will be crowded, Spartan, and dangerous for a few generations, and you and your descendants may never be able to go outside without protective clothing.


    The idea to try to bring a part of the web of life to a dead, inhospitable (to say the very least) heavenly body is totally pointless, not to say bizarre. Living there will be a lifelong depression where the final decomposition . . .

    That's ridiculous. Do you think people who live in the arctic suffer from lifelong depression? Or people who live in the town of Whittier, Alaska, where everyone lives in one large building and they cannot go out 6 month of the year? See:


    https://www.npr.org/2015/01/18…-community-under-one-roof


    Many people who live in noisy, crowded, unnatural cities and who never encounter nature are fine with that. My late aunt preferred that. If someone growing up on Mars craves wide open spaces, camping, and living close to nature, that person will emigrate to Earth. Other people on Earth who crave adventure, technology, and close-knit "corridor culture" dependence on others will go to Mars. It will be like living on a gigantic oil drilling platform, which some people enjoy.


    I have lived in places that many modern Americans would consider boring, or even hellish. Such as the middle of rural nowhere in Japan, long before the Internet was invented, where there was no air conditioning, no place to go, and nothing to do at night. It was very humid and hot by 10 am. So hot that you have to take a siesta and not try to work around 2:00 in the afternoon. You may die of a heat stroke otherwise. The work is hot, tedious and dangerous. There is no flush toilet and the cesspool stinks when it gets hot. There are thousands of acres of beautiful unused forest and inaccessible hills, but you better not go wandering in them because you may be eaten by a 300 lb wild boar, or a bear. Mars is not the only place with dangerous wilderness. (People have guns to shoot larger wildlife; the Japanese government wants more people to own guns.)


    In other words, it is like being a migrant laborer in the U.S. It sure isn't for everyone! But I like it. The people who have lived that way all their lives do not suffer from lifetime depression. Believe it or not, many of them have read more books than you. Some of them know much more about Jane Austen than you do, or about various subjects you have never heard of. They are much better at operating and repairing machinery than you are. Little old ladies operate heavy machinery that will cut off your arm if you make a mistake. They can build houses and barns better than you can. They are self-sufficient. They grow all their own food. If you sent them to Mars they could probably grow all their own food there, too.


    If you have not lived this way, you cannot judge it. People living in caves and corridors on Mars would be self-sufficient, resourceful, and more like those people than like urban Americans.

  • Extracting various elements on Mars, regardless of the energy cost, is not a simple problem. On Earth, in order to have an effective mine, one mineral phase needs to be found that is amenable to extraction, concentration, and purification. If other mineral phases can be found that do not interfere with the processing of the primary phase, then these too might be mined as a byproduct line. The vast majority of raw material mined is waste: only a tiny amount is the target element(s). The waste needs to be dealt with. The typical free energy fantasy is that raw rock or ocean water can have all its elements selectively captured and concentrated, somehow making stockpiles of almost the entire periodic table readily available at no cost. That requires more than two new technologies. It is hundreds of new technologies, and a entirely new type of economy as well.


    Mining asteroids is a hugely uneconomic venture, unless those elements extracted are needed in the immediate vicinity, or maybe downgravity. At some point the cost in energy is so high to find extraterrestrial mineral stockpiles it would be better to make the elements from scratch. And who cares about a boulder of platinum the size of an apartment building when the fact of of its existence and accessibility devalues the price of platinum? Better to carve a space station out of it then send it to Earth. In the early days of immediate pre-colonization, perhaps dropping a few asteroids of rich in various metal contents somewhere convenient on the surface might be a helpful plan. Might also inspire some nefarious plans...

  • Extracting various elements on Mars, regardless of the energy cost, is not a simple problem.

    No one said it is simple. It is profitable. It is a good opportunity because it is not simple. If it were simple that would invite competition.

    The vast majority of raw material mined is waste: only a tiny amount is the target element(s). The waste needs to be dealt with.

    Why does it need to be dealt with? What harm could it cause? Perhaps on Mars pollution might become a problem, but waste material on an asteroid that has been orbiting the sun since the solar system began can be left to orbit. Or dropped into the sun. Thousands of asteroids fall into the sun every year.


    If the mining is done by self-replicating robots using solar energy, the concentration of the ore would not matter. It would take more robots and more energy, but there would be unlimited quantities of both. Whether it takes 100 robots, 1,000, or 100 million robots would not make the slightest difference, and the cost would not be any higher. It would just take a little longer to fabricate the robots.


    Perhaps you have to live in the countryside to get a feel for how this works. Take water, for example. In Atlanta, it is surprisingly expensive. If you accidentally leave the sprinkler running all day, your water bill will be noticeably higher. In contrast, I know of two old houses in the countryside (one in the U.S. and one in Japan) with unlimited supplies of water. Both are on hills, downhill from springs. The springs produce several gallons per minute, and have been producing for hundreds of years. I suppose people used to use buckets, which meant they had to do work to get water, but nowadays they have PVC pipes from the spring to the house. The pipes are pressurized because it is downhill. They do not even need an electric pump. The pipes only tap a small fraction of the water in the spring; the rest goes down the stream. You could open all the taps, fill the bath and the washing machine and water the lawn, and you would not even notice that the stream is a little lower. You could leave the sprinkler running for a week. There is no water bill. No one knows or cares how much water you use. "Conserving" water is meaningless in these circumstances. The fact that water costs money in the city is irrelevant.


    Mining asteroids is a hugely uneconomic venture, unless those elements extracted are needed in the immediate vicinity, or maybe downgravity.

    It would not be uneconomical if energy cost nothing. Solar energy costs nothing. Solar photon sails will cost little, and they can be gigantic. Cold fusion or helium-3 fusion would be virtually free.

  • To summarize, "the waste needs to be dealt with" is an earth-bound way of looking at things. Of course it has to be dealt with on earth! We can't leave mine tailings lying around. That is dangerous pollution. We are so used to the situation on earth that we forget how different it would be if the tailings were on the moon or on an asteroid. It would make no sense to "clean up" waste material on an asteroid that no one will ever see again. The material cannot possibly harm anyone.


    Regarding self-replicating robots, suppose it takes 1 week for a robot to gather materials and fabricate another robot. Suppose you start with 1 robot, and you need 100 robots. That would take 7 weeks. Suppose you need 100 million robots. That would take 27 weeks. No one would care about the 20 extra weeks, or the extra metal and plastic needed to make the robots. When the project finished, you would abandon them along with the tailings. Or perhaps ship a few million to some other project, for a penny each.

  • With unlimited energy, it is more effective to assemble the elements from less useful elements than go great (solar system scale) distances to fetch them. The time required due to massive distances to go to, capture, and return an item from the asteroid belt to near the moon (for example) is extremely significant. Mars is about 3 light minutes away. Jupiter is about 30 light minutes away. (When these planets are close to Earth in their orbits). Many years will required to get something sent from the asteroid belt. It's not like you could order a load of metals and expect them to show up in a couple of weeks, unless you don't mind them arriving at nearly unstoppable velocities.


    The Earth and Mars have a huge gravity well to overcome, so shipping stuff from one planet to the other is extremely costly. It becomes not the material shipped, but the shipping cost that will determine the price. The energy spent is better spent at home (Whether on Earth, the moon, or Mars, etc.) than moving things about up and down planetary scale gravity wells, if possible. Best to get it right where you are than using interplanetary shipping.

  • It is not the making of waste that is the potential problem, it is the scale of material moved in general, most of which ends up as waste. A typical mine now can process 5000 to 20000 tonnes per day. (It will be lighter on Mars). This is equipment and personnel intensive. For the recovery of just one or two elements. The example of robots doing it all at some point is possible. I don't see why colonizing Mars and other planets and moons is impossible, but we are creating a rather large wish list if we think that the unlimited supply of raw materials will easily yield to our demands.

  • Jed,


    My home country Sweden from which I have not yet found any good reason to emigrate, has also experienced emigration waves, notably to North America.

    You can read about it here: https://en.wikipedia.org/wiki/…tion_to_the_United_States

    Several reasons for emigration of 1.3 millions of Swedes are given, none of them lust for adventure. The emigrants were in desperate need for living space in form of arable land with forests and animal life, employment opportunities or religious freedom. Had North America been a desert they would have preferred to die at home instead of emigrating.


    "Mars and the asteroids are empty worlds that have millions of times more material wealth than earth."


    You are using the expression "material wealth" in an erroneous way, it means stuff that is more or less ready for use. It is a very long way to make a bolt out of iron mined from an asteroid. And please don't bring up those self replicating robots again. Though it is interesting to read about them (https://en.wikipedia.org/wiki/Self-replicating_machine)


    I think that a truly self-replicating machine would have to be an entirely new "living" species. Moreover, it will need to have an intelligence equal to or surpassing our own, we have to design an ET. Moreover, ET must be able to survive where we cannot. It must withstand a large temperature interval, it must be impervious to dust and various kinds of radiation. It must also be able to import and store the energy necessary for its operation. Such a clever machine will be heavily dependent on sophisticated sensors and a very advanced data processor. This is not compatible with the harsh environment that it would be required to operate under. Our ET would only function in the cozy environment of a factory for copies of itself or similar accommodation. Then who is going to do the dirty work collecting raw materials and building new factories? The ET: s will have to build stupid remote controlled slave robots that are hardened against a hostile environment. I have nagging feeling that ET is beginning to look more and more like us ...


    "Or people who live in the town of Whittier, Alaska, where everyone lives in one large building and they cannot go out 6 month of the year?"


    Whittier seems to be a nice place in spite of some cold spells in the winter:

    http://www.donanglephotography…tiful-place-day-46-aug-3/


    But please tell me, where did they get all the materials for construction of boats, cars and buildings? Did they 3D-print everything from seaweed and gravel or did they import it from another planet?


    It is interesting to take part of your experiences in rural Japan, thanks. But my opinion is that comparing your toil and trouble with those of a Mars settler running out of food, water, air, body temperature, life is like comparing a breeze to a hurricane. But I do admire the little old japanese ladies, I do.


    But my main message in previous post was not that it would be impossible to colonize Mars. (Even though I still think that a permanent self-sustaining Mars colony is not going to happen because the accounting book will always show only red figures, and that is not sustainable.) My message was that there is no point in doing it. Do you want to be lonely? Be it on an inhabited island. Do you want to gasp for air? Climb a mountain. Do you want to work hard? Build a log cabin using axe and saw. Do you want to be cold? Take off you clothes and have a roll in the snow. For heightened experience some of these activities can be combined.


    Want a faster-than-light trip to Mars: https://www.google.com/mars/?

    No, the green is not grass and the blue is not water. sorry.


    Listen to Alan, a few hours ago he was a candidate for a Mars trip. Using his LENR-powered space ship he has already checked Mars out. No sooner had he arrived than he got homesick missing his new lab.