SkepticLance

Pangloss If you have read every post on this thread, you will noticed a big difference between my arguments and those of my debate opponents. My arguments are backed up by references. e.g. http://www.springerlink.com/content/m4g710l21756x754/ "Suicide rates typically decreased following implementation of a variety of firearm control laws. Suicide-prone individuals seldom substitute other means or go outside legal channels for suicide weapons. Firearm restrictions may decrease the ready accessibility of firearms enough to allow the peak period of suicidality to pass. Conclusion: The findings support gun control measures as a strategy for reducing suicide rates." http://www.nap.edu/openbook.php?record_id=10398&page=33 "In the United States in 1998, firearms accounted for the majority of suicides both in general (57.0%) and among youth 15–24 (61%) (NCIPC, 2000). Suffocation (18.7%; 25%), poisoning (16.6%, 7%), and falls (2.0% both) follow in usage"

Swansont It is more than a conditional suggestion. It is an opinion. Hansen has absolutely no scientific basis for his suggestion, and your willingness to accept his opinion suggests you need to sharpen your own scepticism.

I dd not suggest that the rapid recharge system had been perfected. All new inventions require time to develop to achieve their potential. Here is a different approach. http://www.designnews.com/blog/460000246/post/470018647.html I quote : "Nano-titanate-based lithium batteries have greater energy density than the lead-acid or nickel-metal-hydride batteries of the old EV1. Plus, they have an even more desirable attribute: the ability to recharge in about 10 minutes as opposed to hours. For rapid charging, the Altairnano lithium titanate battery is the leading power source for automotive applications. The uncanny 10-minute recharge time is enabled by nano-materials that dramatically reduce ion travel distance while increasing the surface area available to the ions."

To Mr Skeptic As I pointed out before, widespread ownership of firearms as a protection against a repressive government is simply not needed. Ask any of the IRA in their battles in Northern Ireland. Gun control in that place, and at that time was really tight! And yet those who felt they needed them, got them. In fact, their weapons caches contained machine guns, bazookas, bombs etc. They put up such a fight that the British were unable to control them. Note that I am not making a value judgement about who was right in the IRA battles - just pointing out that, if you are determined enough, gun control cannot stop you. However, that same gun control can save thousands of human lives each year from reducing suicide. There is a big difference between an organisation like the IRA (whether you call them freedom fighters or terrorists) getting firearms, and a single depressed and suicidal person getting a gun when he wants to top himself. Your thesis that free availability of firearms by the citizenry is needed to keep governments under control is just not true. Your final paragraph asks why I do not push for depression tests, instead of gun control. For a start, that is not the theme of this thread. And I have serious doubts as to the efficacy of that approach. I have no such doubts over gun control. The data shows that gun control saves lives. Big time.

Yes Hansen's number is incredible. Current sea level rise is 3 mm per year. For Hansen's figure to be correct, that rate has to accelerate exponentially. I could accept that there may be an increase, but from 3 mm per year to not much less than a metre per year, based on his suggested doubling each decade????? That is not credible.

doG said "The U.S. has more guns per capita than in other nation in the world and yet, 42 countries have higher suicide rates, many of them with much tighter gun restrictions." The above sentence pretty much summarises the logic. It ignores the fact, as I have been at some pains to point out, that availability of guns is only one of the two vital factors determining suicide rate. The other factor is the number of attempts at suicide. And this is far higher in many nations than in the USA. Yet that does not obviate the fact that gun availability is also an important factor. You can reduce suicide rate if you change the culture to reduce the number of attempts, or you can reduce the rate by making guns less available. 42 countries with higher suicide rates. Sure. No problem. They have higher rates because there are more suicidal people. However, their suicide rate would be even higher still if all those would-be suicides got hold of guns. Here is yet another reference proving my points. Not that doG will even read it. Evading the truth is the best way to avoid facing it. http://psychservices.psychiatryonline.org/cgi/content/full/52/8/999 I quote : "Most of us are aware of the grim statistics. Someone dies by suicide in the United States every 17 minutes, for a total each year of more than 30,000. Few of us, however, are aware that 57 percent of those who kill themselves do so with a gun. This group includes about 60 percent of suicides of persons aged 25 years or under and 70 percent of those aged 26 or older. " The quote below reinforces the fact that suicide attempts are not usually genuine. Attempts should fail, allowing the victim a chance to recover. "Hopelessness more than depression predicts suicide. People who commit suicide do not want to die—they simply want to end the pain." Why do suicides occur? This reference states it to be two reasons and the second is access to firearms. "If we understand as much as we do, why are we not seeing a more dramatic decrease in suicide rates in this country? First, only about a third of persons who have depression receive diagnoses and appropriate treatment. Seeking help for depression still involves stigma, and patients and their primary care physicians often fail to recognize depression. Even when affective illness is diagnosed, the treatment provided is often inadequate. Second, we have done little or nothing to limit access to lethal weapons." And here is a nice story on the benefits of gun control. "The effect of gun control was forcibly brought to me recently when a nonphysician colleague asked me to provide psychopharmacologic consultation for a young man whose engagement to be married had been abruptly terminated. He had thought of killing himself the previous week and had gone to a sporting goods store to buy a gun. I asked whether he had purchased one. He looked at me disappointedly and said, "No—in New York State it takes six months to get a license... a lot of good that does!" That man is alive today, getting treatment, and doing better because some members of the community cared enough to legislate to limit access to firearms. " References like this are widely available since so much research has been done linking suicide rate with gun availability. Yet I cannot make headway with gun lovers. Shows how poorly rational argument copes when faced with sheer emotion.

To Deja Vu Thank you for those comments. They meet the ultimate criterion for extreme wisdom. They agree with my own thoughts! (Just kidding) I had concluded right at the start that a space habitat was a better bet. You won't need to adapt humans for microgravity, since you can spin a habitat for artificial gravity. If enough population needs to be housed, you end up with a Dyson swarm. However, the habitats still retain the great virtue of mobility. If something serious enough happens, which is likely if we look at long time spans, such as the sun becoming unstable, then all those habitats can move off to find another home. Our sun is destined to swell into red giant status, and a mobile habitat that can move into a more distant orbit would mean survival. Or the move might come just from a difference of political opinion.

To swansont The reference to Hansen and five metre sea level rise was a paper edition of New Scientist. However, a less specific version can be read on : http://environment.newscientist.com/article/mg19526141.600 I quote from Hansen's words in the web article: "I find it almost inconceivable that "business as usual" climate change will not result in a rise in sea level measured in metres within a century. Am I the only scientist who thinks so?" And a second quote : "As an example, let us say that ice sheet melting adds 1 centimetre to sea level for the decade 2005 to 2015, and that this doubles each decade until the West Antarctic ice sheet is largely depleted. This would yield a rise in sea level of more than 5 metres by 2095. Of course, I cannot prove that my choice of a 10-year doubling time is accurate but I'd bet $1000 to a doughnut that it provides a far better estimate of the ice sheet's contribution to sea level rise than a linear response. In my opinion, if the world warms by 2 °C to 3 °C, such massive sea level rise is inevitable, and a substantial fraction of the rise would occur within a century. Business-as-usual global warming would almost surely send the planet beyond a tipping point, guaranteeing a disastrous degree of sea level rise." Hansen admits that there is no 'proof'. I would say there is no strong evidence either. I would also say that statements such as Hansen's are irresponsible and dangerous, and lead to panicky action that should be avoided. To the capn. You need to re-read my post. I have made no calculation. The IPCC reports that sea level rise is 3 mm per year. That is not exactly a 'back of the envelope' calculation. It is simple empirical observation carried out by experts. So please take care not to say something that leads people to misunderstand my actual message.

I think that doG's departure from this thread is a sign that some logic is finally getting through to him. The concept that making death dealing weapons widely available leads to more deaths is so simple that it takes a major amount of emotion laden illogic to permit denial. When statistics from universities and other reputable sources backs this up, then that illogic becomes more and more based on the emotional. You can follow the argument that Mr Skeptic and ParanoiA presented, in which liberty is given more value than a bunch of extra deaths. As I said, that is an argument based on opinion, and not one that either side can win, because it depends entirely on your individual set of values. However, to deny the basic facts is just illogic.

A new technology which will help provide personal vehicles after oil is on the way. http://www.worldchanging.com/archives/002435.html I quote : "The Japanese tech giant announced today a new generation lithium-ion battery technology which can be recharged to 80% in one minute, with total recharge taking a few minutes more. " Electric cars currently under development are stated to have a range up to 350 kms. Imagine an electric car that has a range that is a large fraction of that - say 250 km - and can be recharged in less than 10 minutes. You drive on your holiday vacation, for 200km. At that stage, you pull into a recharge spot, which might be a cafe with some charge points added. Go in for a recommended safety rest from driving and have a coffee. You pay for your coffee and recharge together, and head off for another 200 kms before another break. Sounds like a pretty good idea for replacing internal combustion powered vehicles to me.

To the Cap'n Either way, it is an extraordinary claim. Bearing in mind that current sea level rise is 3 mm per year, as global average, to suggest even 3 metres by 2100 is incredible. It is also a statement designed to stimulate alarm, even panic. As I have said before, we need a considered, carefully planned, researched and managed approach to remedial action. These kinds of claims are not going to achieve that. Instead, they could result in stupid over-reactions that lead to disaster. It is vital that rational people keep things in perspective. Stupid predictions will not help.

Mr Skeptic said : "Now, that may have only been Patrick Henry's opinion, but it is that opinion that gave us our independence. It is funny that you now say, (paraphrased) We must take away this liberty, lest people put themselves to death." I stated earlier that we already have liberty taken away from us as individuals for the greater good. Liberty must always be a balance. Where greater individual liberty lead to detrement to the greater number, it is regulated. For this reason, all nations regulate against a wide variety of crimes. They remove the liberty to carry out those actions classified as crimes. The proper way to run a country is to operate a careful balance maximising individual liberty while restricting that which harms others. This is precisely what I am talking about with firearms. Widespread access to firearms harms many people, both through increased suicide and through increased homicide. Limiting that access is a small reduction in liberty to maximise the benefits to the greater number. This is part of the proper balance. The argument that access to guns is needed for personal liberty is one that must be balanced against the need to reduce harm to the greater number of people. Obviously, where you draw the line - where you put the balance point - is highly debatable, which is why I said it is pure personal opinion, and no argument on personal opinion can ever be won by one side or the other, since there is no objective data to force a conclusion. To doG You still continue to push illogic. Let me explain again. If we were to put the factors influencing suicide success rates into an equation, it would be something like this. Sd = Sa.Fs Where Sd is numbers of deaths by suicide Sa is number of attempts at suicide Fs is the fraction of attempts that are successful and result in a fatality. So if there are 10,000 suicide attempts, and 60% result in fatalities, then the number of deaths is 10,000 times 0.6 or 6,000 deaths. The number of deaths depends on two factors. Countries like Lithuania and Japan have lots of suicides because the first factor is very high. However, countries like the USA have so many suicides mostly because the second factor is very high. In theory, to reduce suicides, you have to reduce both factors, but sometimes it is easier to concentrate on the dominant factor to get the best result. In Japan, to reduce suicide deaths would require a reduction in attempts - a culture change. In the USA, the best way to reduce suicides is to concentrate on the second factor - the success rate, which would be easily reduced by cutting down on access to firearms. Of the two, it is much easier to reduce access to firearms than to change a culture. Now, if you remember the references I have posted, you will remember that (where guns are not used) there are normally 5 to 25 attempts for every success. Since a large number of those who attempt suicide only try it the once, then reducing the success rate is going to save a hell of a lot of lives.

There is a very simple way of reducing the mass needed for a Dyson sphere. Simply use the advanced genetic engineering techniques no doubt available to modify humans, so that they can live in weightless conditions with no health detrement. If there is no need for Earth level gravity, a Dyson sphere could be made of very thin material.

Swansont You may recall Prof. James Hansen using models to predict a 5 metre rise in sea level by the year 2100. This is the sort of thing I have a problem with. Models simply are not reliable or accurate enough to do this. It is total irresponsibility.

To ParanoiA I think I will decline your debate. I weakened and expressed my opinion earlier, but when the argument is one person's opinion against another, we get nowhere. Thus, I decline. To doG How can I get you to see that your arguments are red herrings? Sure, people without guns can hang themselves. And no. We cannot ban ropes. They are too important to everyday living, which guns are not. The authorities I quoted have said that restricting access to guns would reduce suicide deaths. What they say makes perfect sense. Since 70% of all suicides in the USA use guns ( around 17,000 deaths each year), we can say with close to 100% certainty that the death rate would drop if non hunting firearms were banned to non soldiers/non police. Also, since most homicides in the USA use guns, we can say that the death rate from homicide would drop also. Not immediately by too much since enough guns already exist, but eventually. The short answer is that, if those guns were seriously restricted, a lot of people (many thousands) each year would live who now die. And if they do not have a gun, they will NOT all switch to hanging. That is why the statistics show a 2 to 5 fold increase in suicide risk in homes that have guns.

To Deja Vu Nice numbers. It is always good to see things quantified. I would not write off Jupiter too quickly, though. It, and the other gas giants, do contain a lot of Hydrogen. However, we still do not know what lies beneath the surface, and there might be rocky material equivalent to thousands of Earths. At least!

doG said : "Canada, by your own reference, has very tight control on handguns, yet it still has a higher per capita rate of successful suicides than the U.S.. Why is that?" There are a lot of countries that have a higher suicide rate than the USA. However, that does not impinge on the point I am making, which is that widespread availability of guns, and especially hand-guns increases the rate of successful suicide. As I said before, there are two factors influencing overall suicide rate - motivation and means. a. If motivation is high, that means lots of people attempting suicide. Certain nations, such as Lithuania have a lot more attempts at suicide. Even with a lower success rate, the end result can be more suicides, simply because of the larger number of attempts. b. Access to a method of topping yourself is also important, and that is where guns come in. There may be fewer attempts, but if the 'success' rate is high, that means more deaths. Bearing in mind that most suicide attempts are not genuinely serious, a reduction in success rate (by controlling firearms) will mean fewer attempts are successful. Many unsuccessful suicide attempts are never repeated, since they are really just cries for help. Thus we should try to reduce success rate, and thus reduce suicides. This is what my references have been saying. To ParanoiA When you start arguing that the extra freedom justifies the extra corpses, then you are getting into a sphere of opinion, rather than scientific fact. We could argue that for ever, since we all have our opinion, and on matters of opinion there are no right or wrong answers. I prefer not to get into that discussion too much, since it is good to be able to nail things down with fact. However, just because I am an imperfect human, let me express my opinion anyway. I see a reduction in personal liberty as being an essential part of living in societies. If you are Robinson Crusoe living on your own on a desert island, then you can do anything you like and harm no-one except yourself. However, in society, you have to accept certain limits. The obvious example is not being able to drink and drive, since that may maim or kill other people. Keeping a hand-gun at home can do the same thing. If someone else gets hold of it and commits homicide or suicide, then your possession of the hand-gun has led to another death. To curtail your liberty in that small way, to avoid another human dying, to me is justified.

To swansont I have said that models are not reliable and not accurate. I do not believe I have said they cannot be useful. Models serve many functions, and prediction is only one. My gripe is against those who believe they can be used for valid predictions. If you claim other uses for them, then fine. Edtharan said : "Thus, if there is extra energy within the climate systems, and it is not evenly distributed (as it won't be), then it will cause changes to those climate systems as the energy tries to even out." But as I have pointed out many times, in a warming world, the distribution of temperature is more even. Tropical and temperate regions warm much less than polar regions, and thus temperature differentials are less, not more. Also, I think Edtharan's ideas are a bit simplistic. Energy input verus energy output on a global scale is only the beginning of the picture, and the details are of vital importance. For example : much greater amounts of heat energy can enter the ocean and create a much smaller rise in temperature compared to energy entering the atmosphere. Thus the transfer of energy air/water is of vital importance. Since the oceans can store and transfer massive energy around, oceanic currents become of vital importance, and these are still not as well understood as we would like. Edtharan said : "We have the tools to stop this happening, so if we think that it is a good idea to prevent making life harder for our children, don't you think that it is a good idea to do so?" I am not sure if this coment was directed at me or was more general. Anyway, here is my answer. Yes, of course, we need to act in a proper manner in relation to global climate change. However, as I have said before, we need to make sure our actions are considered, well researched, and carefully planned. There are just too damn many idiots out there screaming for precipitous action. For example : many European countries are importing palm oil as the basis for biofuel. The countries that produce palm oil cut down tropical rain forest to plant oil palms. Result : things are made worse. Panicky, rushed action of this ilk is just stupid. There are things that can be done, which do not carry penalties and we should be doing them. We should not be acting stupidly. A comment about journals such as New Scientist versus peer reviewed ones. NS is written by journalists - but science trained writers. They consult with professional scientists, but word the articles themselves. The result is something we can actually read and understand! The basic facts are normally very accurate, according to the scientific knowledge base of the time. Where interpretation is applied, read with a pinch of salt. But this is true for all articles, including peer reviewed ones. If you look at peer reviewed journals such as Nature or Science, then you get items that are painstakingly accurate. However, you need to read them as though reading a foreign language, with dictionary in hand, unless the article falls within your own specialty. I have had to study a number of such articles for professional reasons, and I have, on occasion, re-written the entire damn thing in plain English before really getting to grips with the content, to the degree required. I suspect that most people simply do not get past the abstract, which makes the value of the article much less.

At last!! Someone who can read references and think rationally. Thank you Mr Skeptic. Your final comment about whether that is sufficient reason to ban guns is, of course, a matter of opinion. My opinion is that guns that are designed purely to kill people such as hand-guns should be strongly restricted, while hunting guns can be available to those with a genuine need. However, that is entering the world of opinion, and others will differ. Since it is opinion, it cannot be 'proved' either way.

To doG You are absolutely determined to ignore all the data, and the supporting studies by reputable researchers, aren't you? Instead you pretend that I am denying other suicide methods. Of course I am not. People use all sorts of methods to commit suicide. However, unless the would be suicide is absolutely determined to top himself, other methods are less successful than gun suicide. Since I am talking about the USA, here is a reference from the NIH. http://www.nimh.nih.gov/health/publications/suicide-in-the-us-statistics-and-prevention.shtml "Suicide is a major, preventable public health problem. In 2004, it was the eleventh leading cause of death in the U.S., accounting for 32,439 deaths.1 The overall rate was 10.9 suicide deaths per 100,000 people.1 An estimated eight to 25 attempted suicides occur per every suicide death.2" Showing as I said, that more attempts than successful suicides happen. So what makes an attempt successful? Clearly, if a more lethal means is used, like a hand-gun, there is a greater chance of a death resulting. From my NIH reference. "Suicide was the eighth leading cause of death for males and the sixteenth leading cause of death for females in 2004.1 Almost four times as many males as females die by suicide.1 Firearms, suffocation, and poison are by far the most common methods of suicide, overall. However, men and women differ in the method used, as shown below.1 Suicide by: Males (%) Females (%) Firearms 57% 32% Suffocation 23% 20% Poisoning 13% 38% " This shows clearly that the use of firearms increases lethality of suicide attempts. It also shows that, in the USA where guns are widely available, firearms are the preferred suicide choice. Hanging may be more common in places where guns are restricted, but in the USA it is guns that cause the most suicides, almost certainly due to the wide availability of guns. The earlier studies I referenced shows that successful suicide is more prevalent where guns are available.

doG You keep harping on the suggestion that all intended suicides would kill themselves even if they did not have guns. The comparitive statistics Canada vs USA would deny that. High access to guns correlates with high rates of successful suicide. This is not my opinion. This is hard data. Obviously a suicide does not occur unless the person affected has both intent and means. Increase the number of people with intent, and you increase the number of suicides. Increase the number of people with means and you also increase the number of suicides. That is why wider access to firearms leads to more suicides. Of the two, reducing access to the means of suicide, and especially firearms, is the easiest means of reducing suicide rate. Sure, I agree that, if a person is determined enough, you cannot stop them. But most would-be suicides are not actually that determined. Like our friend Taktiq, who 'wanted' to commit suicide, but never tried using the gun he had access to. However, you need to realise that people who contemplate suicide are not psychologically 'normal'. It is probably not too far from the truth to regard them as temporarily insane. And people in that state will sometimes resort to a gun even if they really do not want to kill themselves. Result, an unnecessary death. http://www.urmc.edu/pr/news/story.cfm?id=282 I quote : "A handgun in the home significantly increases the risk of suicide in men over the age of 50, researchers from the University of Rochester Medical Center show in an article in the July-August issue of the American Journal of Geriatric Psychiatry. People with a handgun in the home were more than twice as likely to kill themselves compared to similar people who don't have access to handguns. The finding wasn't true for long guns such as rifles and shotguns, whose presence did not boost suicide risk." It is really easy to find credible references, such as University research, showing the relationship between gun availability and suicide rate. These are facts, not opinions. The above reference relates primarily to older people. The reference below is more about younger. http://archpedi.ama-assn.org/cgi/content/abstract/147/10/1066 "Even after adjusting for differences in rates of psychiatric disorders between suicide victims and controls, the association between suicide and both any gun (odds ratio [OR] = 4.4, 95% confidence interval [CI] = 1.1 to 17.5) and handguns (OR = 9.4, 95% CI = 1.7 to 53.9) in the home were both highly significant. Long-guns in the home were associated with suicide only in rural areas, whereas handguns were more closely associated with suicide in urban areas. " This article recommends that, if an adolescent is suicidal, it is important to remove access to firearms.

To swansont We seem to have crossed paths. I wrote my last post without seeing yours. We must have been putting them in together. First : reliability of my references. If I post a reference from New Scientist, it is reliable in terms of fact. Interpretation, of course, is always debatable. My references are, like anyone else's, reliable if taken on those terms. I also have to say that I am always suspicious of debaters who fail to address points, but attack people or references instead. Sometimes that is a sign of a weak argument. If I post something from a biased political source, of course you can challenge it. However, my references have not been from that source. Second : ," "All models are wrong, but some are useful." " I could not agree more. However, accuracy also varies. Some astronomical models, for example, which are based on equations known to be accurate to umpteen decimal places, and have as inputs, facts that are likewise enormously accurate, may produce outcomes that are incredibly accurate. Global Climate Models do not fit this category. Your comments about unknowns are right on the button. But it goes beyond volcanoes and solar output. As I have shown recently, it extends to oceanic currents that behave in unexpected ways, and to wind patterns that have unexpected effects (Antarctica), and to uncertainties in the formation of clouds. There are sure to be other unknowns that currently live up to their name, and which will show themselves in due course. The time may come when all significant unknowns are accounted for, and models perform close to flawlessly, but that is not today. I suspect that if you are honest with yourself, you will admit that you know this already.

One of the funny things about suicide does, in fact, relate to intent. My own reading suggests that most suicide attempts are not actually that serious. Many are simply cries for help. That is why 98% of those who take drug overdoses actually survive. That is also why it is the more tragic when people use a firearm in their attempt. A firearm is 90% sure of killing in a suicide. 16,000 Americans in 2001 died that way. How many of them were not really serious and would have survived if they had access to only less lethal methods? I suspect the answer would be most of them. We will never know, since you cannot interview a successful suicide! However, the comparisons I put up between USA and Canada, using real official statistics, shows that in Canada, where guns are less readily available, the rate of successful suicide is way lower than in the USA.

Edtharan said "Essentially what they are doing is seeing what their model would have predicted if it were available at some time in the past." That's true, but still ignores many unknown factors. That's why they are called unknowns. When the first models were set up, their accuracy was much less, since many factors were not well understood - there were more unknowns. Since then, models have improved, but recent reports still show serious errors due to other unknowns that keep appearing. The Arctic ice melt was a major one. Even where modellers think they understand, often there are uncertainties. For example : there are several theories as to why the main bulk of Antarctica does not warm as they predicted. They do not understand the mechanism. That does not stop them applying a 'fudge' factor. But if you do not fully understand mechanisms, how can you be sure that your model is accurate? You cannot, and predictions continue to be off, as shown by the various references I have put up.

To Sayonara I guess I got sidetracked on the security issue. You are correct that an H bomb would be a disaster to a swarm as well as a sphere. I think we can agree that bastards with nuclear weapons are catastrophic in any society. I have to admit also that I had not considered the solar sail possibility in relation to moving a Dyson sphere. You would not use sails, of course, since the entire inner surface of a sphere is a kind of sail. What you would need is a means of altering the reflectance/absorbance of that inner surface. A degree of thrust could be obtained by absorbing charged particles from the solar wind, versus reflecting them, or perhaps channeling them to the outside. So one side of the sphere becomes equivalent of a mirror and the other similar to a black absorbing surface. I do not know how much thrust you could get that way. Would it be enough to move something weighing more than the entire solar system? I do not know. To insane alien A point you may not have taken into account. The Dyson swarm does not need to be dense. In fact, for safety reasons, it is probable that a large minimum distance be set between habitats. However, a thinly spread swarm that occupies a space between (say) 1 to 5 AUs from the sun could still intercept pretty much all the energy while still staying well away from each other. The habitats further out could use widespread collectors or concentrating mirrors to take in the more diffuse solar energy they need. Assuming they were not burning deuterium instead.