SaxonViolence Posted August 17, 2013 Report Share Posted August 17, 2013 (edited) I touched on this briefly in a couple other folk's threads. Congratulations. We're finally ready to launch a colony to an Earth-Like Planet. A.} Assume that it is very expensive. Some folks question whether Earth would ever squander so much on a very long-term goal. Well, somehow we've convinced them. We can't assume that they will stay convinced over decades or even centuries. We have to plan this as a one-shot deal. We can't rely on a second wave arriving thirty years after the first. If we launch more waves—cool. We can't count on them. ******************* *************** *************** Just for the sake of argument: Travel time one-way is somewhat over 200 years. Average speed is about .3C. Our colonists will travel in cold sleep and there will be 3500 of them. **************** ************* ****************** B.} Some folks might groove on the simple lifestyle, but let us assume that few, if any of our colonists want their great-great grandchildren living the hunter-gatherer stone-age lifestyle. I'd even say that it is unconscionable to send people if that is a high probability outcome. The mission is to Bootstrap up to a sustainable level of technology as rapidly as possible. Define: 1860's level steam power and metallurgy... Iron and Steel aren't terribly hard to come by. Neither are Copper, Tin, Zinc, Lead, Gold and Silver. If you have Gold and Silver alloy, you will inevitably have a little Platinum that could be extracted. They built Chronometers, Sextants, Treadle Lathes like the "Goodell-Prat" or "The Britannia"... They built Locomotives, Steam Ships, Colt Revolvers, Marlin Rifles, Hypodermic Needles and Buckboard Plows... All with roughly nothing better than 1018 Steel and some creative case hardening here and there. Once we get to that level, we can relax a bit. Presumably we brought beaucoup books—printed on Archival Quality Paper—There will be a few Durable High Tech items around for a couple hundred years at least. When the Technologic and Social Infrastructure will support it, progress won't have to be nearly so blind and random. ************** ******************* ********************** Yeah, I personally know how to find and smelt Iron ore, how to prospect for Gold and Silver... And I've been pondering how to create my own Metal Working Treadle Lathe and how to recreate the Old H&R Topbreak Revolvers in a simple Home Workshop for some time. My projects don't get done, largely because I tend to be a low-energy day-dreaming type and I'm very poor. I assure you that my goals are easily achievable though. {Hell, there are dudes recreating very elaborate Antique Pocket Watches on Small Foot-Driven Watchmaker's Lathes. Ain't Rocket Science people...} What I have no idea how to do, is refine Chrome, Nickel, Molybdenum; Vanadium, Manganese in any appreciable quantity. It is my understanding that you have to Distill huge amounts of Iron ores and separate them out. Never mind. Eli Whitney, William Quantrill, John Browning, and Henry Ford got by with Simple 1018 Steel. {Not to mention Edison and the Wright Brothers...} So can our colony....At least for the first 200 years or so... I think... ********************* ****************** ****************** Read an excellent Anthropology Extract many years (decades) ago. It argued that the sophistication of a Society is constrained by the number of full-time, non food-producing specialists that it can afford to feed. Yip-EE-Ki-AAyy!!! C.} Even with 3500 colonists—a nice generous number—one very important thing our colonist need to concentrate on is: "Go forth. Be Fruitful. Multiply!" A word for any Cranky Feminists: Posit any type future society that you please. Yet unless we have plenty-beaucoup artificial wombs to carry along... Bearing Children is a very important Logistic Function of Women in a Space Colony. **************** *************** ******************** The woman across the street from us was a neighborhood legend with her nine children back when I was a boy. My mother and father had two children. They would have loved to have more. Nether of them ever briefly considered any sort of Birth Control. ************ ***************** ********************* ZPG Replacement Rate is about 2.2 Children per couple—in the US. Lets assume that even the replacement rate will be higher in our colony (due to more accidental deaths before siring/bearing and at least a bit more infertility). It is highly desirable (I think) to try to double the population every generation—at least in the beginning. Aiming for an Average of slightly above 5 children per couple should more than accomplish this modest goal. How long is a generation? Well Grizzelda may have Colleen at the age of 16 and Colleen may have Anya at the age of 18. But if Grizzelda spreads her children apart, and doesn't have Rosalind until she (Grizzelda) is 30, and Anya has her last child at 34... **************** **************** ********************* Some women, despite being carefully examined beforehand, will end up unable to conceive. Presumably, in a free society, a few women may change their mind and refuse to have any children—despite strong social pressure to produce. Some may find themselves either unable or unwilling to have the proverbial 5. Some may chose to spit one out every 10 months and end up with a lifetime total of 20 or 30. Just what percentage of women could reasonably safely and successfully bear 5 children in their lives? What is a reasonable maximum (Good Practice—Not third-world happenstance) number of children for a woman to bear? ********************* ***************** ************ 3500 is more than enough folks to avoid problems with inbreeding... And just how "Inheritable" greatness is, is a topic of hot debate. Let us assume though, that our ship carries a huge abundance of Frozen Sperm—enough to last the first 100-150 years—and all of it taken from men who display some sort of genius or great talent. If even one super-talented person results, it could be of incalculable benefit to the colony. At worst, it brings in some welcome genetic diversity. Heinlein once theorized that in a Nouveau Pioneering Society a woman wouldn't wed until she'd proven her fertility by conceiving. OUCH! That puts the Al-Kabong!!! On any sort of Sexual Propriety—don't it? Also, I am a strong believer in Primogeniture... ******************* **************** **************** The custom might be for a young woman to be impregnated artificially with Frozen Sperm before betrothal—Thus proving her fertility while simultaneously preserving her Virtue. And the Custom might be for her Parents to raise the Virgin-Born child as their own... Since if the child was male, her future husband wouldn't care to leave the family estate to a foundling, nor would it be fair to raise him as a "Designated Cad". But some might choose to bear later children from the Sperm Bank—as well as giving children to husbandless women and raising up Seed for sterile men. {As a general rule, once an infant is sired and born to a donor, his sperm is not used again...} *************** ***************** ******************* This really puts the Rush into things. Ralph and Rachel may each have a fine top-quality steel Bowie and Axe from Earth—Along with Shovels, Hoes and Rakes with unbreakable polypropylene handles. Which of the twelve children or eighty some-odd grandchildren inherit Ralph and Rachel's Bowies? ************* **************** ******************** Okay, if you were mission planner— What high-tech or medium-tech items would you stockpile in preference to all others? It wouldn't make sense to send many tons of Steel Slabs. If our folks don't get a Steel Industry started soon, they're hurtin' for certain anyway. A ton or two of Small Molybdenum or Vanadium ingots might really leaven the Early Machine Age Era. Or not? *************** ***************** ***************** Let us also assume: The people on the ground have more pressing matters than setting up a huge antennae and punching messages through to Earth—Messages that won't arrive in their lifetime, much less get a response. Orbiting platforms can broadcast, but may only have a general idea what is happening on the surface. After forty to sixty years the orbiting platforms will cease broadcasting. ************** *************** ******************** Finally, we've prevailed on The Powers That Be to send a second, follow-up mission. We have strong reason to believe that the 1st mission was sucessful—nonetheless, Second Wave is semi self-supporting if need be. 2700 men and women, another freezer full of Spermsicles, Varieties of Crops and Livestock that the 1st wave didn't take. Mainly though... Arriving blind over 120 years after the 1st lander—What would you expect to find the original colonist's descendants most in need of ? Point Two: Assume that most of the descendants of the 1st wave are living in or near small railroad towns—Part "Little House on The Prairie"; part old "B" Western—with maybe a smidgen of "Roadwarrior" thrown in. {Or am I too Optimistic? Too Pessimistic?} Anyway, here your Colony lands with all sorts of High-Tech Goodies... Space Colony Santa Clauses as it were... Some of which the 2nd wave thoroughly intends to hold onto, and support themselves in at least a "Higher Tech" state of existence than their backward kin... Are the 20 000 to 30 000 1st wave descendant going to have enough respect for Private Property to let that happen? {Even though Arguably, a higher tech enclave in their midst might speed up the overall march of progress considerably...} Like I say—Always researching Story Ideas. Anyone's input appreciated. These are the type questions that even the most thorough Thinkers never seem to address. Anything that I'm overlooking myself? Saxon Violence Edited August 17, 2013 by SaxonViolence Quote Link to comment Share on other sites More sharing options...
CraigD Posted August 18, 2013 Report Share Posted August 18, 2013 Anything that I'm overlooking myself?I think you’re not so much overlooking something, SV, as assuming that the best or only way to transport a genetically viable population of humans somewhere is in functioning human bodies – a reasonable one, given that that’s the only way it’s ever been done, but one I think ill-considered, and one that’s been rejected by the IMHO more thoughtful SF writers for at least 30 years. James Hogan’s 1982 SF novel Voyage from Yesteryear starts with the premise that, sometime about now (as imagined in 1982), a fairly small robotic interstellar spacecraft has successfully carried the genomes of a large human population in digital storage, which with a small amount of biological feedstock and a sophisticated microbiological manufacturing machinery, are assembled into actual DNA in fertilized ova, gestated in artificial wombs, raised to adulthood by robotic caregivers, and released to colonize an Earth-like planet. Hogan got some details wrong (not bad research – he was imaging the early 21st century from the late 20th), but mostly in the conservative direction, assuming that only a few hundred genomes could be stored in a reasonably small digital storage device. In fact, the human genome’s roughly 6,000,000,000 base pairs takes only about 12,000,000,000 bits. There are 8,000,000,000,000,000,000 bit storage devices on the commercial market now, a few of which would be enough to store the genomes of all 7,000,000,000 individuals now on earth. So storage isn’t a problem for mere 2013 technology. Actually high-fidelity recording (“sequencing”) many humans’ genomes is beyond the present state of the art, but just slightly, no more than 10 years away, I guess (though the subject is complicated). Being able to synthesize a human genome from pure data and seed it in a zygote is entirely beyond the present state of the art, but perhaps not too much. No Artificial wombs has yet born a mammalian embryo, and is a difficult technical challenge (not to mention a political and ethical minefield), but are feasible in principle. From a mass and durability perspective, something like this – if not the as-yet-SF technology of digitally stored genomes robotically restored to biological cells, the more near-term feasible scheme of frozen fertilized eggs transferred to artificial wombs) is vastly more efficient way to get a human population to another planet than the old-fashioned gametes-in-a-walking, talking-body method. There’s an encyclopedic rundown of the concept at this wikipedia article. Quote Link to comment Share on other sites More sharing options...
SaxonViolence Posted August 18, 2013 Author Report Share Posted August 18, 2013 I had considered the idea, but hadn't much explored it. One thing that I had asked myself... Babies raised with a bare minimum of human interaction—as in certain institutions—often fail to thrive and they can grow up with somewhat deficient Social Skills... Or occasionally, Very Deficient Social Skills... Assume that: A.} We have fairly humanoid Androids to raise our First Generation. And Just for the sake of Argument, lets say that, B.} The Androids Facial Expressions and Body Language are both noticeably wooden and just a bit off-kilter. With plenty of "Loving" attention, we shouldn't raise a Colony full of Catatonic Autistics and Murderous Sociopaths... {Especially since the children will also be given plenty of time to interact with each other.} But Assume their Personal Skills come out measurably lacking. Let us further assume that we reproduce the second generation and all subsequent ones the traditional way. Our 1st generation does a better job of Imprinting their children than the Androids—they are human after all— But their children come out partially Wanked. How many Generations until the effects of being raised by Androids vanishes? {Yes, I am assuming. It is quite conceivable that the Androids might have perfectly adequate Facial and Body Language.} Saxon Violence Quote Link to comment Share on other sites More sharing options...
Mountain Posted September 24, 2013 Report Share Posted September 24, 2013 One problem that I see right off the bat is the number of the population, 3,500 people is not enough for a good breeding population. You would likely wind up with a high level of genetic problems from such a small initial breeding population. If they spanned the human genome in characteristics and they kept very accurate records and marriage was assigned for genetic viability maybe. I have always thought that if we were to travel to another solar system we really need to have ships themselves be adequate for survival and providing sustainable life at the destination on the long term. Such as sending say a five to six mile wide asteroid on the journey, with the actual ship imbedded within the center of it. The asteroid at that size could a sizeable ship and population within. The interior of the asteroid could be mined while in transit for propulsion. At the destination it could be brought into permanent orbit around chosen planet/moon and used as a long term base of operations. My biggest thought in a long term high velocity space voyage is all the little and large bodies floating out there, collisions are bound to happen. The asteroid may provide some protection from at least smaller collisions. At even 1 million mph the ability to maneuver to avoid something is pretty dang tough even at great distances. Having many, many billions of tons of easily mined material available in orbit of a new planet would not be such a bad thing either, especially with the ability to machine and produce from that same facility. Quote Link to comment Share on other sites More sharing options...
SaxonViolence Posted September 25, 2013 Author Report Share Posted September 25, 2013 (edited) Hmm. I read somewhere that the latest research indicates that 500 people would be quite enough to start a healthy colony breeding wise. As I said, children are wealth in agricultural communities. Heinlein once suggested that women not be wed until they proved their fertility by getting pregnant. But Heinlein was a hopeless old reprobate with no regard for Chastity. Point two: Many men (certainly not all, but some) would be a bit ambivalent about raising a child that wasn't theirs. I'd suggest that the colony take a large bank of stored frozen sperm—from the most superior men that they could get sperm from. Greatness or genius may not be entirely genetic—but having some good stuff couldn't hurt. The custom would be for young women to be artificially inseminated for their first pregnancy via the sperm bank... Thus proving her fertility AND preserving her chastity. Traditionally the child would be raised by her parents. No rule says that women can't have more sperm-bank children for whatever reason—they don't marry, they're widowed, their husband isn't fertile, they just like to goose the gene-pool... But say that the average woman bears 5.4 children in the colony. Almost 100% bear their first child from the sperm bank (and each donor is generally only used once)... How much genetic diversity does this add to the mix? The math is beyond me. Saxon Violence The hollow asteroid may have advantages over the Ramjet. Edited September 25, 2013 by SaxonViolence Quote Link to comment Share on other sites More sharing options...
Mountain Posted September 26, 2013 Report Share Posted September 26, 2013 Well in all technicality, I suppose you could have an ova bank as well as a sperm bank and simply implant within a woman, then you could represent pretty much all the genetic variety of the human race. Maternal dna is only passed down to females from the mother, paternal dna is as we know passed from the father to the son. With 3,500 people you would likely have a population of what about 1,750 females, this is a start of 1,750 maternal lines, the number can never get any bigger but would certainly over time get smaller. This does not mean retardation but it is somewhat constricting on genetic diversity. The human race as a whole already lacks much in the genetic diversity department. We know that lack of diversity in the gene pool often precedes extinction. On the hollow asteroid idea, well I did not mean to hollow it out, just build say a 1/4 mile wide by say 1+ mile long cylinder into the center of it, rotate the cylinder at a slow speed and you have a source of gravity/centrifugal force. You would also have enough area that you could conceivably grow crops within it. At 1/4 mile by 1.5 miles the area on the inside of the cylinder wall would be right about 47 acres, that is enough for a lot of planting. The main reason I think an asteroid is the way to go though, is the idea that you can then use nuclear power plants built within to power your propulsion, using the mined asteroid material as the propellant. The asteroid would also serve as a protection from radiation and small impact. I did some research the other day and found that I am certainly not the first to come up with this idea, Dandridge MacFarland Cole came up with this idea in the 60's working for NASA. I think it could be conceivable to someday build a number of asteroids into ships like this and sling shot them out of the solar system together for a small colonizing fleet. Equip each asteroid with a number small ships and they would have the ability to transport between ships during the journey, effect repairs, trade materials etc. With enough of these together even if you did not find a habitable planet where you went you could still maintain and live aboard your ships, even expanding the living and growing potential of each of them and potentially gathering more asteroids in the new solar system to be used in the same way. Moving a large asteroid would certainly be a feat, but with the amount fuel they would contain, literally billions of billions of tons of fuel that could be mined, being heated and run through an accelerator would provide a massive amount of propulsion over a long journey. Quote Link to comment Share on other sites More sharing options...
CraigD Posted September 27, 2013 Report Share Posted September 27, 2013 We’ve an odd mix of biology and astrophysics in this thread – seems like good hypographic fun to me! :) Maternal dna is only passed down to females from the mother, paternal dna is as we know passed from the father to the son.This idea has been strongly suspected to be false since the discovery, enabled by advances in microscopes, of XY sex determination system, ca 1905, and know in detail to be since the availability of high-detail statistical DNA analysis since the 1980s, and especially since the availability of true gene sequencing since the 1990s. Genes on the Y chromosome can only be inherited from the father. However, only about 1% of the genes in the human genome are on the Y chromosome. As men and women both have chromosomes 1 through 21 and X, there are no nuclear genes that can be inherited only from the mother. The entirely separate mitochondrial genome[/url is inherited only from the mother, but has a tiny number of genes compared to the nuclear (37 vs 3,079,843,747), and these genes regulate only the mitochondria, not any important somatic traits. Although differences in mitochondrial genomes are useful in population genetics and medicine, they aren’t very important to the health of a population. In short, a population with no men in it – which would have to use artificial techniques to reproduce – would lack only a few genes. One of them, however, SRY, is very important, because it produces males. To put it another way, assuming they could artificially reproduce, two men could produce both male and female offspring, but two women could produce only females. None of the artificial techniques I mention exist yet. With 3,500 people you would likely have a population of what about 1,750 females, this is a start of 1,750 maternal lines, the number can never get any bigger but would certainly over time get smaller.As I explained above, there is no such thing, biologically, as paternal and maternal lines. Matrilineality and Patrilineality are mostly cultural and legal systems. For a colony of naturally-breeding humans to increase its numbers as fast as possible, it should have only as many men as are necessary to impregnate the woman as many times as possible. Because men and women are essentially “equal carriers” of genetic diversity, this would not cause inbreeding or other genetic problems. It might, however, offend many cultural rules – though only for 1 generation (about 15-25 years, depending on cultural rules), as within a generation, the number of men and women in the population would be about equal. The human race as a whole already lacks much in the genetic diversity department. We know that lack of diversity in the gene pool often precedes extinction.I think it’s important to consider carefully what genetic diversity means, scientifically, and understand that it means something very different than the sociological idea of “racial” and “ethnic diversity”. Genetic diversity means that a population has a lot of different genes in it. “Racial diversity” (a term not much used by sociologists) means a population that has a lot of different-looking individuals in it. “Ethnic diversity” means a population that has a lot of different “cultures” – collections of shared norms, “values”, myths, etc – and typically “racial diversity”. To get racial diversity, a two-step process must occur:Populations reduce their genetically diverse, so that the genes that produce noticeably different outwardly visible traits identified with race, such as skin and hair color are restricted to produce an identifiable “race”Two or more of these separate “race” population then “mix” into a single community.Though the genetic diversities of the separate populations are reduced, the genetic diversity of the entire human population in this process is little changed. Somewhat paradoxically, increased racial and ethnic diversity require isolate pockets of reduced genetic diversity. On the hollow asteroid idea, well I did not mean to hollow it out, just build say a 1/4 mile wide by say 1+ mile long cylinder into the center of it, rotate the cylinder at a slow speed and you have a source of gravity/centrifugal force.Though this idea is common in science fiction, I believe there’s a growing consensus among minor body astronomers that it wouldn’t work, because most or all asteroids larger than about 200 m across are not solid, but rather “rubble piles” held together by gravity. This is mostly because, as more data is gathered, no asteroid larger than about 200 m has been observed rotating faster than once every 2.2 hours (source: NASA’s Cosmos: “How fast do asteroids spin”). Models based on solid bodies show that some should be, so there must be no asteroids larger than 200 m across that could withstand the forces of being spun to produce a noticeable positive net centrifugal force in a chamber inside them. Perhaps the approach could be saved by reinforcing a big rubble pile with something similar to the wire rockfall mesh, but made of something stronger, such as carbon fiber. Moving a large asteroid would certainly be a feat, but with the amount fuel they would contain, literally billions of billions of tons of fuel that could be mined, being heated and run through an accelerator would provide a massive amount of propulsion over a long journey.Where do you get that asteroids contain much fuel? Mountain. That is, what’re you sources and calculations? I don’t have sources and calculations of my own, but my guess is you couldn’t change the velocity of an asteroid much using energy from fuels on it. Fuels are essentially either hydrogen and oxygen ,hydrocarbons and oxygen, radioactive elements, or, perhaps, hydrogen to fuse to helium (as in a H-bomb). I believe asteroids have roughly the same fractions of elements as the planets, about 32% iron, 30% oxygen, 16% silicon, 15% magnesium, less than 2% any single other element, less than 0.1% carbon. From which I get a rocket mass ratio of less than 10%. Optimistically assuming this give a fuel:mass ratio of about 0.05:1, so per the rocket equation assuming a high-performance rocket [imath]v_e = 5000 \,\mbox(m/s)[/imath], [imath]\Delta v \dot= 5000 \ln \frac {1} {0.85} \dot= 234 \,\mbox(m/s)[/imath], only a small fraction of the solar escape speed - orbital speed of a typical asteroid, about 36000 – 25000 = 11000 m/s. Even the most cunning gravity assists, I don’t think you could escape a body from the solar system with such a small [imath]\Delta v[/imath]. Perhaps many asteroids could be mined to get fuel for a single one, but I’d have to see details of such a plan before hazarding a guess if this is practical or even possible. JMJones0424 1 Quote Link to comment Share on other sites More sharing options...
Mountain Posted September 27, 2013 Report Share Posted September 27, 2013 Where do I begin................ In humans the mitochondrial dna (maternal) codes for 37 genes and has about 16,000 base pairs. In most species including humans, mtdna is inherited solely from the mother. Ydna has about 50 million base pairs and is passed solely from father to son, the y chromosome is one of the fastest evolving chromosomes in the human genome. You can look these up on wiki or on any other site dealing with dna or genetics. As for human diversity, a quick read in the American Journal of Human Genetics...."The distribution of human genetic diversity has long been a subject of interest, and it has important implications for human evolution, forensics, and the distribution of genetic diseases in populations. Genetic diversity in human populations is low relative to that in many other species, attesting to the recent origin and small size of the ancestral human population (Li and Sadler 1991; Crouau-Roy et al. 1996; Kaessmann et al 1999." In my opinion you would want a full representation of as much as the human genome as possible to start out at a new planet rather than severely bottlenecking it.The total number of human genes is at 20,500, that is not a great amount, we have around 10 million genes active within us doing the job of keeping us alive, but the vast majority are genes within the bacteria and other single celled organisms within us. Could a group of 3,500 colonize another planet successfully... yes... would it have a notable genetic effect over time... yes... Would greater amounts of genetic variability effect the likely long term survival of the group... yes.. ---On the hollow asteroid idea, well I did not mean to hollow it out, just build say a 1/4 mile wide by say 1+ mile long cylinder into the center of it, rotate the cylinder at a slow speed and you have a source of gravity/centrifugal force.--- (Though this idea is common in science fiction, I believe there’s a growing consensus among minor body astronomers that it wouldn’t work, because most or all asteroids larger than about 200 m across are not solid, but rather “rubble piles” held together by gravity. This is mostly because, as more data is gathered, no asteroid larger than about 200 m has been observed rotating faster than once every 2.2 hours (source: NASA’s Cosmos: “How fast do asteroids spin”). Models based on solid bodies show that some should be, so there must be no asteroids larger than 200 m across that could withstand the forces of being spun to produce a noticeable positive net centrifugal force in a chamber inside them.) Note.... it does say rotate the cylinder.... not the asteroid....At 1/4 mile diameter, the cylinder would have to rotate at about 27.8 rotations per hour to give full earth gravity effect. In reality you would likely go for something more like 1/5 earth gravity, making less than 6 rotations per hour. This would cause the asteroid to want to turn in the opposite direction yes, but with a much greater mass it would turn at a much slower rate. As for rotation of asteroids, every asteroid that has passed by us in the last couple years has had a rotation, proven by the radar studies that we have done of them. Vesta is certainly large, and it has a rotation of 5.432 hours and is 326 miles in diameter, that is a rotational speed of 188 miles per hour, many times what you would need to simulate earth gravity. I understand that Vesta is not the average asteroid, I am just using it because there is very specific and reliable recent data on it. There are in fact a great many large asteroids in this solar system that are in fact NOT a big pile of rubble clumped together and we know this for fact from radar studies of asteroids passing close to earth over the last few years and the visit to Vesta. I have watched the video of each of them pass and studied the data and pictures of all of the passing asteroids in the last few years. As for fuel in an asteroid, well they do hold a fair amount of water and other things that could create fuel, but the fuel would simply be the "mass".... on earth air can be used as a compressed fuel, it does not burn or explode it simply has inertial mass which creates thrust. The fuel in an asteroid would be the asteroid..... you turn the material into a plasma and magnetically propel it out at speed creating inertial thrust. The greater the speed the you propel it out the greater the thrust, the greater the mass of what your propelling out the greater the thrust. On earth this would be unfeasible, but in the vacuum of space it is not all that difficult to turn stone or metal into a plasma. Certainly it would require vast amounts of energy to create a propulsion system to utilize asteroid material as the propellant. Currently we have ion drives using various different fuels, one of them uses mercury as a fuel. Same basic propulsion idea just vastly scaled up and using the available mass of the asteroid as the propellant. This would require energy on the level of large nuclear power plants, to turn the asteroid material into a plasma, and to accelerate the plasma to gain thrust from it. You might read some of the current articles on asteroid mining, quite fascinating and they give some good numbers on the make up of the asteroid chemical makeups. Right now they are looking at them as a great source of water, fuel and metal able to be mined much cheaper in space than to be launched from earth. The amounts they are calculating from even small asteroids is rather amazing. Quote Link to comment Share on other sites More sharing options...
SaxonViolence Posted September 30, 2013 Author Report Share Posted September 30, 2013 (edited) Well in all technicality, I suppose you could have an ova bank as well as a sperm bank and simply implant within a woman, then you could represent pretty much all the genetic variety of the human race. Maternal dna is only passed down to females from the mother, paternal dna is as we know passed from the father to the son. With 3,500 people you would likely have a population of what about 1,750 females, this is a start of 1,750 maternal lines, the number can never get any bigger but would certainly over time get smaller. This does not mean retardation but it is somewhat constricting on genetic diversity. The human race as a whole already lacks much in the genetic diversity department. We know that lack of diversity in the gene pool often precedes extinction. In the imaginary society that I imagined, the majority of women have one artificially inseminated child from the Sperm Bank Before she is married and her Parents raise the child. The child is her parents Real Grandchild and her future husband doesn't have to feel he's been Cuckolded by the Sperm Bank. Implanting Ova would result in a child who is Kin to no one and who's Biological Parents are light years away. Saxon Violence Edited September 30, 2013 by SaxonViolence Quote Link to comment Share on other sites More sharing options...
Mountain Posted October 1, 2013 Report Share Posted October 1, 2013 I fail to see where it would make a difference to most people whether the child was biologically theirs or not. I have raised three children not biologically mine for many years. My wife is paraplegic and has been for right at 13 years, the doctors are warning us that we have really beat the odds but that is not going to last for too much longer, her bone infection is pretty bad and there is nothing that can be done at this point. I will continue to raise the oldest boys as my own even after she is gone, I feel no differently toward them than I do my own biological children. I understand my view is not everyones, my first daughter died of cancer when she was young and so my view of children in general has been changed a bit. I think you might be surprised how many people would raise any child no matter it's biology. Quote Link to comment Share on other sites More sharing options...
CraigD Posted October 1, 2013 Report Share Posted October 1, 2013 Ydna has about 50 million base pairs and is passed solely from father to son, the y chromosome is one of the fastest evolving chromosomes in the human genome.Yes, but my point was, addressing your original statementsI suppose you could have an ova bank as well as a sperm bank and simply implant within a woman, then you could represent pretty much all the genetic variety of the human race. andMaternal dna is only passed down to females from the mother, paternal dna is as we know passed from the father to the son.that “paternal DNA” consists entirely of genes on the Y chromosome, and that, because the Y chromosome contains so few of the total number of genes in the entire human genome (454 of 32185 according to this handy table at Wikipedia), it’s not necessary to have about as many genomes with a Y chromosome (men’s) as ones without (women’s) in a starting population. With at least one very important exception – the SRY gene I mentions in post #7, which causes a human to be male - you’d have about the same number of unique gene’s (we’ve been using gene in a colloquial way so far, and having strained this to the point of me qualifying it with “unique”, better note that what we really mean when we talk about a population’s genetic diversity is the number of alleles, unique forms of the 32185 or 31731 genes every normal individual human has, and begin using this term. Non-colloquially speaking, all individuals of the same species have the same genes – it is the collection of alleles of these genes that differ between individuals) in a population of all or nearly all women, or all or nearly all men, as in a population of nearly equal numbers of men and women. Excepting only SRY and a few others male gender-specific genes, “paternal gene” isn’t a scientifically meaningful concept. With no exceptions, “maternal gene” is scientifically meaningless. At least I think this is true. Perhaps there are some other important genes unique to Y chromosome. I’m not a genetic biologist, so have done only a small amount of inexpert, internet-based research, but in that, have found no credible suggestion of this, though, so can only stick with my conclusion above. If someone can find a reference explaining otherwise, I’d be grateful and edified. I’d be surprised if it were the case, though, as if a genes on the Y chromosome were important to population health other than assuring the population has males, it would be important to individual health, and as no women have Y chromosomes, all women would suffer from health problems related to their lack. ---On the hollow asteroid idea, well I did not mean to hollow it out, just build say a 1/4 mile wide by say 1+ mile long cylinder into the center of it, rotate the cylinder at a slow speed and you have a source of gravity/centrifugal force.---I understood that. My point was that, as astronomers are coming to understand asteroids, that isn’t possible, because an asteroid larger than about 200 m in diameter cannot be spun at a rate that imparts a centrifugal acceleration greater than its surface gravity without coming apart. Vesta is certainly large, and it has a rotation of 5.432 hours and is 326 miles in diameter, that is a rotational speed of 188 miles per hour, many times what you would need to simulate earth gravityCan you show your calculations for this, Mountain? Mine show this claim to be badly wrong. The longest radius or 4 Vesta is about r=286300 m. Its period of rotation is about p=19231 s (about 5.34 hrs, close to the value you gave). Centripetal acceleration [math]A = \frac{v^2}{r}[/math]where [math]v = \frac{2 \pi r}{p}[/math]so for the Vesta example above, A= 0.03056 m/s/s. This is about 321 times smaller than the acceleration of gravity on Earth (about 9.8 m/s/s), and 8 time smaller than the surface acceleration of Vesta (about 0.25 m/s/s). I can see no reason in principle that you couldn’t excavate a large washer-shaped part of the interior of a large asteroid, and spin a centrifuge of any shape, including a cylinder, or a ring, in it, in which case the surface of the asteroid wouldn’t need to rotate faster than usual, or at all. But given that the surrounding asteroid is so massive, requiring so much work to move, I can’t see that this would be useful other than in providing a simulated gravity environment within a asteroid that remained in its usual orbit. In the imaginary society that I imagined, the majority of women have one artificially inseminated child from the Sperm Bank Before she is married and her Parents raise the child. The child is her parents Real Grandchild and her future husband doesn't have to feel he's been Cuckolded by the Sperm Bank. Implanting Ova would result in a child who is Kin to no one and who's Biological Parents are light years away. I fail to see where it would make a difference to most people whether the child was biologically theirs or not. I have raised three children not biologically mine for many years.I agree. I’ve also been involved in raising children who both were and were not my offspring, and felt most closely related to one who was not my offspring. The social circumstances – in my case, a long marriage to the mother of a child who was not my offspring – were more important than biological paternity. I’ve known many people with similar experiences, and none with the experience of harming or refusing to care for a dependent child who was not their offspring. My wife is paraplegic and has been for right at 13 years, the doctors are warning us that we have really beat the odds but that is not going to last for too much longer, her bone infection is pretty bad and there is nothing that can be done at this point. I will continue to raise the oldest boys as my own even after she is gone, I feel no differently toward them than I do my own biological children.I believe you are to be praised for you attitude, Mountain. I also believe it’s one shared by nearly every parent with parenting experience like ours. I am aware of data showing that the incidence of sever child abuse committed by stepparents, especially stepfathers, is greater than for committed by biological parents. I believe this is not a direct effect, but rather because the factors that result in biological parents not raising children together also result such parents being more likely to commit sever child abuse. JMJones0424 1 Quote Link to comment Share on other sites More sharing options...
moonguy Posted October 1, 2013 Report Share Posted October 1, 2013 I seriously doubt we would attempt interstellar colonization with just one ship. That said, we should reconsider strategies that have people in deep sleep or hibernating or frozen for the journey. This actually multiplies the chance for failure as it takes the anticipatory and reactionary capabilities of the human mind out of circulation. Human history is all about meeting challenges - but not while we are sleeping. Quote Link to comment Share on other sites More sharing options...
SaxonViolence Posted October 1, 2013 Author Report Share Posted October 1, 2013 CraigD, You may be right. There are certainly good and kind people who Adopt Orphans and love them and treat them no differently than their own. Maybe this is less rare and special a trait than I thought. It would certainly disrupt a system of rigid male primogeniture—Which I would assume the Colony would want to reinstitute since it is the most equitable system and has the most survival potential for a society who's continued survival is at stake. Moonguy, Yeah, if they decided to go, it might make far more sense to send a whole fleet of ships. I really have trouble believing that the colonization of other star systems will ever happen. It takes many years, perhaps decades of effort to build a ship—or ships... Look what happened to our American Super Collider... But it is fun to think about. As far as live Vs frozen folks... It's not necessarily Either/Or. You could have an ample Multi-Generational Crew awake and many more folks in cold storage. If you could use CraigD's artificial rooms & if the wombs could be adjusted to grow almost grown bodies & you had mastered personality transfer... It might be easier to simple go with Beaucoup stored memories and lots of raw material—you know, protein, fats, minerals—whatever—to build the bodies on site. Saxon Violence Quote Link to comment Share on other sites More sharing options...
moonguy Posted October 2, 2013 Report Share Posted October 2, 2013 I see your point. Ironically, this is a subject of one of my future postings regarding Mercury colonization.I wonder if we would do it if the best planet we could find was a lonely outpost planet no better endowed than Mars for survival? Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.