Sayonara

Ridiculous argument aside, icebergs do displace their own mass in water, but it's not just floating icebergs which are melting. There is also ice which is on land, and ice which is otherwise locked out of the ocean system. The OP has been answered and I am now closing this thread.

Pioneer, the authors use thermodynamics as an analogy only. Trying to address the strategy they propose in terms of actual thermodynamics results in gibberish. The topic of this thread is a therapy which uses mutagenic drugs to drive fitness to negative levels.

If you are going to go, just go. The dying swan routine has never worked here.

So does "in those words" include the words which you removed? I'd assume both would be occurring tbh.

And that's the inevitable trend when you go from zero resource exploitation to moderate resource exploitation - it says very little about mankind's abilities to improve exploitation, other than progress can occur over time. What do you think the inevitable trend might be when you go from moderate exploitation to near-complete exploitation? Do you think it will remain the same? The question I asked you in my last two posts was:

Except that it's not, because we are discussing a very long-term scenario which revolves around events that Earth hasn't yet encountered. In contrast, Ehrlich and Simon disagree on very short-term market fluctuations over a time period during which nothing substantially extraordinary happened whatsoever. I am not being pessimistic by pointing out a potential problem which you don't believe is possible. And even if I were, it would have no bearing on the veracity of my arguments. Lose the red herring. We are discussing timescales that run into centuries - the case in point is different by orders of magnitude. Strawman: I don't make the statement that anything will "suddenly stop now". Logic failure: Past trends do not guarantee future events. Hypocrisy: You yourself said yesterday that you do not trust predictive models which extend far into the future. While you may feel that diminishing returns simply drives progress elsewhere you are still ignoring the simple principle that limits eventually arise in any given system of consumption. Which simply goes to show that a point of unattainability is being reached by virtue of economic viability. We have already been over this several times. Depends what you mean by "expands the resource tenfold", and it depends on the specific circumstances which dictate that lower-yield extraction process. You are being very vague with the details when you make these sweeping assertions. For a while, assuming we learn how to do it, and assuming an economical process exists. Yes, I know you predict that. You keep predicting it every other post. What you don't do, however, is provide any reason why anyone should consider it to be at all likely, or reliable enough a strategy to place our faith in. All you have backed it up with is allusions to historical progress (which, in the context of the civilisation we are describing, is essentially the history of small numbers of people scraping up mud) and constant repetition. The question I asked you in my last post was:

Let's hope so. Really? That seems like a very short period of time. Economically, we could probably do it at a push. But because of social and political reasons, it would have to be one hell of a push. Lance has commented on my "pessimism" once or twice in this thread so I am going to take the time to point out that actually, I sincerely and genuinely hope that I am wrong, and that mankind spreads to the stars without any resource hitches. However I am not about to modify my analysis of the situation based on some arbitrary feelings I happen to have. No, my main objection to your logic is that it relies on valid objections being ignored. You have not attempted to plug this gap by tackling the easily-approachable and well-documented economic and socio-political problems I have described, but instead back-tracked on your past claims that you don't like to see speculation in science threads and presented a possible but highly unlikely technology as a catch-all that renders the entire discussion moot by suddenly providing the planet with more resources than mankind can wave a requisition order at. Yes, I believe that was something of the point I was making. Finally. Which is great because it frees up some platinum for other uses. But there are three problems with that: 1) It doesn't demonstrate that platinum can be substituted out of any space-oriented application which might conceivably require it, 2) It merely shifts the resource burden elsewhere, 3) Guess what - the quantity of platinum hasn't increased. You still have to pick which one of the two things you want to be able to do, and a resource is sequestered somewhere. On point 3, note that the more you find that the 'chemically interesting' qualities of an element qualify it for a particular application, the less likely it becomes that a potential substitute is going to be common. I applaud your faith in man's genius, but implying that any material resource can be and will be substituted at some point is blasé and largely based on presumption. It also simply pushes back the resource burden elsewhere, which is hardly solving the problem. Legion they may be, but legion does not mean eternal, absolute, infallible, or any of the other words that you need it to mean. As Mr Skeptic and I touched on, the body of the craft is not much of an issue. It's likely that if all spacecraft were composed entirely of the same materials as the hull, then we would easily be able to establish a solar resource network of some sort before Earth's resource made such an operation problematic. But that is NOT the problem I am describing. Let me put it like this: Rockets, probes, space suits, EVA equipment, tools, station modules, scientific equipment, sensors and detector arrays, robotic systems, environmental controls, thruster assemblies, CO2 scrubbers, computer networks, solar arrays, shielding, drive systems, and so on and so forth, all require very specific resources. In this future we are describing, we will also have the added resource requirements of colony habitats, impact shielding, water harvesting and reclamation, supply shuttles, and whatever recreational or scientific tools/vehicles/items the occupants require or desire. We also need the vehicles and other mechanisms required to fabricate those things and put them in place, not to mention the resources required to actually keep them operating at the minimum level that anyone would describe as successful. And of course then there is the resource harvesting network. How many harvesters? A hundred? A thousand? A hundred thousand? Will they be autonomous or crewed? They'll need some kind of maintenance facility, a depot or silos to deliver resources to, and of course some kind of refinery and separation facility. A navigation network would also be quite handy. Now, imagine that this is being put into place on a timescale of many, many decades, perhaps even centuries. Meanwhile, back on Earth... civilisation is becoming increasingly mechanised and technology is diversifying. Resources are being consumed at an accelerating rate and the range of exploitation of chemical resources increases as novel applications are found. Now the question is this: are you prepared to make the claim that the organisation or authority managing the implementation of a sol-wide resource mining operation could guarantee their access to the raw materials they need to make that possible, without having predicted and stockpiled the requisite volumes perhaps hundreds of years beforehand? Bearing in mind that many of the resources civilisation has heavily relied on for less than a century now have predicted limits within our own lifetimes.

Sometimes homicide investigators have a bit of a rational wobble and accept the advice of "psychics", but like Mooeypoo I think you would find it difficult to cite any case which has been solved purely on the basis of such a person's input. The word telepath does not mean mentally ill, so your statement is factually incorrect. We do not use phrases such as 'by definition' because they sound good; they have a specified meaning. This statement makes no sense. While I agree on some levels with this proposal, I don't see how steps 1-3 lead to it, and I do not see what step 4 has to do with anything else you said.

Rabbits look much better with blusher and a bit of lippy.

Infraction issued. I think this might serve as a caution to other users that if you are drunk when you post, you are still responsible for the content that you submit.

I'm saying may be unavailable, but for all intents and purposes in this discussion we can probably agree it amounts to the same thing. An important condition is that I am not talking about any arbitrary spacecraft, but the machinery and infrastructure needed to successfully and permanently migrate beyond Earth. Remember what the topic is; "What Will Man Become". No, you have it backwards. Cost is a product of availability, and as the latter falls, the former rises. You cannot simply ignore the point where cost becomes prohibitive, and you cannot simply ignore the point where the requisition capacity you need is just not there. I think what you mean to say is that unit cost determines the viability of requisitioning a particular material...? It's not helpful or meaningful to compare the impact of the cost of materials to the impact of something which has no bearing on their availability or value. Also, the proportion of a mission's budget which is dedicated to acquiring materials is based on the cost of those materials, not the other way around. Budgets which are exceeded because of the effects of the material cost do not typically get a green light, regardless of how impressive the design phase is. Inevitably there will be occasions where they are either unwilling or unable to source materials at their market value. As global resource utilisation increases, these occasions will become more likely. It seems to me that the assumption that NASA will still be around when we start genuine efforts to spread off Earth indicates that you misjudge just how far away we are from that day. Logical error. The market value of the required materials is not determined by the relevant proportion of a mission budget which NASA have set for themselves. Exactly. The longer we leave it, the more likely it becomes that the resource cost of this endeavour reaches orders requiring the backing of a collaboration of nation states. I feel I should mention at this point that one has to keep the likely timescales in mind, to keep a sense of perspective.

Nobody is arguing against that statement because it is true. The points of discussion you neglected to address were those relating to the rare elements (which I for one repeatedly invited you to comment on), and the principle of something being unavailable for use if it is already in use elsewhere. And that would be lovely, if it is ever done. Ideally it would work as advertised or better, and render this debate moot. Or as a wacky alternative, economics. This does not mean anything can be substituted. Or alternatively, you do to this discussion what ignoring a physical law does to all those discussions about light speed. I very much hope that my fears are never realised, but what is or is not likely is not contigent on the emotional response certain humans have to that concept. All I am saying is that it is possible we will shoot ourselves in the foot with regard to successfully migrating off this planet. I haven't yet seen any convincing counter-argument showing how that is impossible, and I am not really sure why it is such a massive bone of contention in this thread. Yes, because some will start to become so scarce as to economically force substitution with a less ideal material. Unsupported assertion, unless you only consider human-devised combinant materials, which somewhat begs the question. As long as you ignore the materials which have historically risen in cost and/or not changed at all. Come back to Earth, Lance.

Just to clarify (and stay on topic), are you sceptical about the ice age predictions, the aversion prediction, or both?

You're missing the point of me identifying that space technology requires resources which are scarce. Human civilisation uses them elsewhere now, and will increasingly do so in any future in which space mining is a theoretically attainable endeavour. That is what the repeated references in this thread to "you can't have your cake and eat it" from myself and others actually mean. I didn't say that you are glossing over the flat fact that building requires materials; I am saying that you are disregarding the ongoing point that the scarcity of rare elements is a more realistic problem for a space mining operation than the scarcity of common elements. In other words, it's all very well pointing out that we have enough steel, carbon, or whatever to build the hull and the bulkheads of a hypothetical mining vessel, but that's not going to mean anything if we can't source enough unused tellurium (for example) to make a useful number of these vessels operable. This problem is repeated throughout all kinds of technologies, and as time goes by the problem will worsen. This occurs because (i) civilisation grows more technologically complex and more densely mechanised, which sequesters resources, and (ii) resources which were previously not high-demand can be made so by emerging technologies. Competition is the natural result. There is the additional problem I mentioned earlier which relates to nation states with a controlling share in the planet's reserves of certain materials, and/or access to the only or few sites where these materials can be found. This was pretty much ignored by everyone despite its obvious importance. But the biggest materials cost when building a spacecraft is not necessarily going to be due to the material of which the greatest mass is required. Those are useful properties for some space applications, but I would hazard a guess that you have started with the "useful properties of carbon" list and neglected to check it against the "problems a space vessel will encounter" list. Errr... I am not going to say what I wanted to say here because I think you may be envisioning some system which hasn't occurred to me. Having said that, whatever it is you have in mind could stand further explanation. Even when we can make them with relative ease, it won't remove the demand burden on reserves of the materials that carbon nanotubes and artificial diamonds cannot replace, so the point is moot. That simply moves the goalposts. The argument is "finite mass means finite concurrent applications", not "things get used up more quickly as time goes on" (although that is also the case in many instances, which I briefly talked about when I gave those metal forecasts which Lance ignored). Technology is spreading and diversifying. Its spread is becoming more pervasive and occurring over greater ranger. Demand for virtually every element you would need to build a functioning spacecraft is rising. The rise will accelerate. This demand makes it harder for everyone to get the volumes they need. It is a very basic concept and I personally don't think that its involvement in this topic is so complicated or subtle or arcane that it should be difficult to grasp. You also have no way of demonstrating that a future technology will not require "more" materials. More materials compared to what? What will you measure the first ever space mining vessel against? Nothing, because there haven't been any. So try the other direction: hypothetically, do you think it will be as streamlined and efficient as a 12th generation vessel designed for the same purpose? I should hope not. Right... don't really see how this is relevant. You are still talking about craft mass, which is neither here nor there, and your assertions about fuel cost don't really have anything to do with the topic. In fact I think you are basing this "most of the mass of the spaceship is fuel" on rockets launched from the surface of the planet, which doesn't inherently have anything to do with space-based mining. Well, I mean obviously fuels are materials which could theoretically become too scarce to allow space travel, but let's assume (to make things easier) that we have unlimited energy from mumble mumble mumble. As with all the other elements and materials I have mentioned, I am not making the claim that we will run out because we have shot it all into space. I am making the claim that the paucity of certain resources might prohibit those space efforts being realised in the first place. Such resources don't even have to be entirely physically unavailable; politically or economically unavailable will do just as well. I realise I talked about not getting the gold back from deep space earlier on. That was to illustrate the effect of losing mass, cost, and value at the same time, and should not be confused with my main point. Ah right, you are not actually talking about simple self-replication then. You are talking about something that relies on orders more complexity and a great deal more of your assumptions being correct. And lots of total implausibility as well. We could make a whole other thread about the problems with this idea. And you still have the problem of time. It's nice to imagine such cheerful technologies as nanobots but when you are talking about the technology needed to mine the solar system, the further into the future you cast your gaze, the worse the resource strain will be for the civilisation operating in that period if they are at that technological level. I am not sure it matters any more, in light of the above. Well, firstly I said useful efforts, and secondly that political promise does not insure all known and unforseen resources against depletion or sequesterment before interplanetary migration requires them. ... It's difficult to know what to say to that because - from comments like that one - I'm having trouble imagining what sort of a crazy venture you are planning. Not in dispute. The issue of contention is whether or not by that point we will be sufficiently capable for it to make any difference. I have repeatedly stated throughout the thread what sort of threshold I am talking about. I am talking about the sort of threshold which involves the entire usable supply of materials which are necessary for the manufacture and operation of spacecraft being irrecoverably utilised elsewhere, (and therefore unavailable for the ventures which ironically might push the threshold up considerably.) Arrrgh. Whether or not they are the greatest cost to a project is simply irrelevant. What matters is their availability to the project in totality, which is a product of material costs, project budgets, and physical availability. Forget it; the whole composition thing is just making this discussion too complex to follow, without really making the main points any more or less credible. The only really pertinent point to take from spacecraft composition is that half-decent space tech does require access to some very scarce elements.

Well as I already indicated this is possibly more to do with your lack of interest in the composition of complete space flight systems, rather than it being a very cheap enterprise. I acknowledge that much of the cost of a mission (which can run into the billions) is spent on ground support, logistics, and impressive salaries, but the fact is that raw materials are an important factor too. It's funny that you should mention gold. In point of fact, gold is used extensively in all manner of space systems and many of the detector assemblies and payloads which they carry. Doubtless there is enough gold on Earth to build many such systems, but not an endless number of them and - this is the important bit, the same "you can't have your cake and eat it" theme that hasn't yet been convincingly dispelled - once you blast that gold into deep space you probably aren't going to get it back, which means it can't be used for anything else (e.g. currency). So you lose the mass, the cost, AND the value. Other elements which have been mentioned in this thread already are uniquely crucial to some existing and emerging technologies which make certain space operations possible, and they are in extremely short supply because their abundance on Earth is in the order of one part in 1x1027 or less. Glossing over that fact is highly disingenuous, particularly when one acknowledges that new technologies developed for harvesting materials in space, and possibly also refining them and using them in construction, are likely to require material combinations which aren't currently used, or aren't currently high demand enough to noticeably deplete any particular reserves. I don't think that is really very likely at all, given the physical properties of carbon. Certainly it will be used in space systems, but not for the superstructure, instrumentation, data systems, energy systems, or hull. Given that you excluded propulsion already I am not sure what is left. I suppose that you could argue that, for example, most of the mass of a space elevator which uses a carbon-nanotube tether is carbon, but these are an orbital link system which means that their existence does not harm my proposition that resource paucity could halt interplanetary migration. Also, you seem to be making the error that you expect the largest portion of the ship's mass to correspond to an investment in the most precious material, which is not necessarily going to be the case at all. That's pure speculation. It also betrays a fairly fatal flaw in your reasoning. I don't believe, having read that off-the-cuff comment, that you have considered what sort of scope an off-planet mining operation will need to have in order to become more economically viable to its designers, supporters and investors than the alternative choice of mining the guts out of Earth and passing on the consequences to future generations. I don't really understand what you mean by this. "Fuel" is stored energy, so the sentence is a bit confusing. Interesting, but a source would help people to evaluate the relevance. Again, you can't have your cake and eat it. Think about how (i) conservation of mass and (ii) inertia might affect this plan. Exactly my point; earlier is better. However the socio-political mess which our civilisation has created for itself will probably prevent any useful attempts until it is too late. Not to be too pedantic, but the moon does have an atmosphere. Don't think it has enough mass to significantly impact the railgun idea though (about 10 tons in total, hardly worth mentioning!) There is quite a lot of aluminium and silicon up there, which is obviously very helpful and certainly worth exploring further. To determine that you'd need to do a serious cost-benefit analysis, taking into account the cost of not only building the colony, but maintaining it and the people living/working there. This would need to be weighed against the benefit of the materials and research that we would get out of it, and of course all the related risks. Note that I'm not saying that I would expect such an analysis to produce the answer "no thanks", but that without any such investigation your claim is a hollow assumption that simply repeats your proposition and does not supply it with anything of evidential value. Sigh. Unless a critical theshold says it's too late to start. Usually a combination of all of them. But the point to take away is not "projects in the future will only be cancelled for exactly the same reasons as projects in the past" (which would be factually incorrect in any case), it is that often the cost or physical viability of even highly beneficial mission proposals vastly exceeds the investment which its backer is willing to make. I am not going to reply to SkepticLance's comments on resource availability any more, because he is using his usual tactic of ignoring the rational objections and simply waiting for a bit then re-stating his proposals later on in what looks like a war of attrition against the people who disagree with him. This is not a form of debate which I really want to waste much time on, so I won't be engaging SL until he addresses the outstanding points that I have raised which conflict with his ideas.

m0tvl, can you think of a way in which this idea might be tested?

I suppose an obvious answer to the polygamy question would be that the state grants marriage licences in part to validate tax benefits. If a person could take as many married partners as they wished then you might end up with entire villages taking the piss.

Not to mention the factual innaccuracies, such as... oh I don't know... animals having the same rights as humans. They don't. I wish people would read the thread before posting so they at least have some grasp about the basics of the complex issue that they somehow feel outraged about.

Yes, five points for you ParanoiA, having read back a page I appear to have been mixing questions. Skeptic's average offspring question makes sense now Yes, many of these threads eventually attract people who post comments I find offensive. I don't really see anything wrong with being emotive as long as the counter is sufficient. In this case I have been a bit off aim. It has been a funny old day hasn't it? Mistaking, not misrepresenting.

And what's the problem with that, exactly? We have been through this already. Stop trolling. Again, you have ignored very basic points. 1) Most countries in the West want the birth rate to drop; 2) Marriage doesn't make it any more or less possible for anyone to have a child; 3) There is no "Bureau of Genetic Purity" which checks that each baby born is the offspring of two people who are married to each other. If all you've got are false requirements, you should seriously think about letting that one go. You really don't. Not when you think it is acceptable to make such spurious comments as "Next thing I know you will be telling me that there is no medicinal difference between blacks and whites, because whites can also get malaria. It really does matter that blacks are more susceptible, even if only by a little". Firstly, nobody is offended "because you gave valid differences". Secondly, it does not appear that anyone is 'offended' per se, but that they simply disagree with you, which is completely different. If people are being short with you I think you will find it is because your rationale is tiresome and disingenuous, and your 'differences' are both trivial and immaterial to Proposition 8. Sorry to be so blunt but you really have been asking for that for several posts. Look, it's simple: nobody is denying that homosexual and heterosexual couples are not different in any way. Of course they are different. But this is entirely unrelated to the concept of LEGAL EQUALITY. Your mission to prove that homo~ and heterosexual marriages are 'different' is a complete waste of everyone's time, and it's encouraging you to say things that are going to get you into arguments that you can do without. It's not even answering the right question: as iNow pointed out... "I asked what valid reasons there were in favor of the State treating homosexual unions any differently than heterosexual unions." The nearest you have got to talking about that is population control, and you got that backwards. So excuuuuuse me if I don't have much faith in your analysis of the social ramifications of your position. Which is a healthy question to ask of any 'proof' that is the exclusive product of a value system, but in this case you are wrong. What you are saying is that heterosexual and homosexual marriages are different because some people think the former is "right" and the latter "wrong", some people think the opposite, some people think both are "right", and doubtless there are some people who for whatever reason think that both are wrong. But these are not intrinsic differences between the unions. These are differences between, and only between, the opinions of the different groups of observers. Citing that as a difference between homosexual and heterosexual marriages is intellectually bankrupt. Given your stance on value systems, I'm pretty sure that is not what you intended.

What's irrelevant is your baseless claim that the genetic contribution of both parents is a prerequisite for married partners to have a child. I don't see what that has to do with anything. I really won't be telling you that. Get off your high horse.

No, it's not. The proposition was that a homosexual marriage cannot produce children, not "an unassisted same-sex couple can't have a child which is their own genetic product". Male partners can employ surrogacy and female partners can use donor sperm. All cases can adopt. The rest of your post is moot as far as that concern goes. That unlikeliness is not due to homosexual males having no desire to start a family; it's due to legal and social barriers, and the same good old fashioned string-em-up prejudice that comes from the promulgators of disingenuous poppycock such as "gays can't have children" *. And you say "population is an important part of a country", as if (a) nobody has noticed that the human population is dangerously high, and (b) it wasn't already mentioned in this very thread that the number of children awaiting new parents likely outnumbers all prospective adoptive couples put together, homosexual and heterosexual alike. * I know you haven't said that, just to be clear.

I agree. But if someone is going to use "this is why it's not a real marriage..." as their argument then they ought to be limited to stating things which are true. Be assured that my major bone of contention with that post was that (1) was false, not that it was or was not something setting homosexual and heterosexual marriages apart.

Almost five years... best bit of necromancy we have had around here so far I think.

Think about what the terms are, and how they are related. What does "massive" mean? What is kinetic energy? How do these relate to a body's speed?