Perhaps. But why isn't there life on the Moon? Not possible, right? It may well be that life in space is just not possible. I can tell you this, the energetics of space travel are such that unless we master nuclear energy (fusion, actually), we won't get very far.
You compare space travel to the new world, but there is a big difference. If you're a settler in Lousiana you can still live and procreate with no technology. You can't do that on the moon if your life support fails. A better Earth-bound analogy is the oceans (above or below the surface); and despite that horrible Kevin Kostner movie, we haven't colonized the oceans. We travel across them, yes, but we don't live there.
But your comment reminded me of an interesting question - Fermi's paradox. If life is able to traverse interstellar distances, even limited to sublight, why isn't the Galaxy swarming? Or more to the point, why aren't they here? It doesn't take many generations of exponential growth to fill a galaxy, and ten billion years is a long time for life to start, develop interstellar travel, and start expanding. Given that stars are usually no more than a few light-years apart, you could imagine that you could send out colonies, that in turn sent out further colonies with a generational time of a few hundred years. In a few million years you have the Galaxy.
There aren't very many possible answers: a) interstellar travel is impossible, b) we're unique, c) they're already here or d) they're on their way. Options b) and d) are statistically extremely unlikely. (I vote for c!:)
We have been able to manufacture CNT composite materials on the order of meters in length with strengths on the order of several GPa's now for a couple of years. Currently, steady progress is being made to increase the strength of the composites to the required ~100 GPa.
Well, a factor of 20 in strength is a factor of twenty, and you have a factor of 10,000,000 to go in length. I mean, all we need to make a good single-stage-to-orbit vehicle with current materials is a rocket with a specific impulse of ~1000 (from the rocket equation. With and Isp of 1000 you can make your vehicle out of cast iron and still make orbit). The Shuttle has an Isp of 455 - so it's only a factor of two off. Must be easy, right? My point is that "almost there" can be the same as "not there". (If you aren't up on your propulsion physics, there is no way in hell you can get a chemical rocket with an Isp of 1000. Not enough chemical energy in the bonds.).
I'm not saying beanstalks are impossible. I'm just saying that it's a bit too early to plan your vacation on Mars. I'd love it if I saw one in my lifetime, but I doubt I will. And I'm not that old.
People running around claiming these things are just around the corner are a) bound to be disappointed, b) will end up causing a backlash in the general public when the promises fail to appear (ask Joe Schmoe about flying cars, or electricity too cheap to meter, or vacations on the Moon. Now ask him for his tax dollars so you can develop this fancy new form of space travel. Good luck!)
To put current data on a line, I've heard of nanotubes of three yards.
Please provide a reference. I'd love to see progress with nanotubes. Of course, if they really are making macroscopic lengths of nanotube then there are plenty of applications - high-strength composites come to mind. But I' am far from convinced that that has actually been done. Let's see the first suspension bridge made from carbon nanotubes before we start talking about beanstalks.
The spacedebris problem was solved years ago, +10 cm and larger pieces will be detected by ground radars and avoided by a movable tether, the same for sattelites obviously. Smaller then 10cm debris isn't a very serious threat for the tether.
If you define "solved" as some guy claiming it can be done based on no solid analysis. Tether dynamics are notoriously difficult to manage, and I doubt that you could actually get the tether where you wanted it. I can flat-out guarantee that it's not "solved", just that we maybe have an inkling of where to start. Also, do not discount the kinetic energy in a 9-cm chunk of debris travelling at 10 km/s. It WILL punch through a tether; I guess you can have a lattice of multiple tethers or something, but again, it's not exactly solved.
As for slippage, I don't know about that. But I figure if I could make a nanotube as long as the entire lift length it'll become irrelevant anyway.
Well, no, because you have to repair the tether, splice in new pieces, etc etc. As for those Chinese guys - reference please. There is again a big difference between fusing together a few microns worth of nanotubes and making a string 40,000 km in length. And nanotubes are about as slippery as graphite (a very good lube, except for in certain applications:). It'll be hard to braid the tether, and it'll be hard to climb up it.
there are already materials that are hard to get here on earth, and can be found in abundance in space.
Name a few where the price exceeds $10,000/kg and there is a demand for more than a few kg. (Plutonium doesn't count!)
Remember, if you are willing to spend 20-200 G$ on initial investment, you have to consider if the same elements can be obtained on the ground for even a fraction of such an enormous investment (ocean mining anyone?).
Look, I don't mean to piss in everyones beer, but in my experience the community of space enthusiasts suffers from a lack of realistic thinking. People are talking about beanstalks when we can hardly get a few guys into low Earth orbit, let alone past the Moon. I think we need to keep the dream alive, but the best way to do that is to get your various governments to spend the G$ needed to bootstrap spacetravel into viability.
And despite what you think, governments have access to very sharp people who do think critically about these things and have tremendous engineering talent and experience. They won't be swayed by poorly thought-out ideas or wishful thinking. And yes, it has to be governments, as they are the only organizations that have the astronomical quantities of cash that we are talking about. The USA can drop $8.7e10 in one year to clean up daddys mess (let's not get started on that one!); what company can do the same? (hell, if you stacked $87B in dollar bills it would reach almost to geosync. THAT's pretty mind-boggling.)
Who said anything about current prices? If/when a space elevator is built, which isn't to far off, launch prices will plummet, fuel requirements to reach other parts of the solar system will be greatly reduced, bringing cargo/people down from orbit will be infinitly safer, and the technologies that will be developed once space access is cheap will only improve all of these factors.
I wish I still had my youthful enthusiasm, but having seen Mir re-enter, the Concorde retired, the Shuttle explode twice, and the level of apathy in the American public, I just don't see it happening. Sorry.
A space elevator ("beanstalk") is very far off, regardless of the hype. Even if they could make carbon nanotube strands longer than 10 microns, and even if they could braid them in a fashion where they wouldn't slip, they'd still have to launch a few thousand tons worth of stuff into geosynch orbit. And then they'd have to figure out how to avoid getting the tether cut by space debris... If I see it in my lifetime I'll die a happy man.
Look, space mining and space development in general is a great idea. It just won't happen - there is too much of a chicken-and-egg problem. Someday maybe, when we need He3 and we've figured out how to make a good tether, and we've found a high specific-impulse engine, then perhaps it'll happen. But like I said, don't hold your breath.
The moon could be made out of cocaine and it wouldn't make economic sense to go get it. At current prices, it's $20,000 to get a kilogram of mass into Earth orbit. You're talking hundreds of billions in investment to get a mining colony in the astroid belt. Taking the Apollo missions as a starting point, and saying you could be 100 times more efficient, it's still $100,000/kg material returned.
The materials (iron, rare earths, iridium, nickel) that you could bring back simply do not command prices high enough to make it worthwhile - they're in the few dollars to few hundred dollars/kg range.
This might change IF someone invented fusion that worked, and required He3. Then it might be worth it. Don't call me until that happens... and don't hold your breath, either.
There is no need to stretch the analogy too far, it served merely to show that the attitude "lets get started now, and figure out the details later" isn't always a wise choice of action.
The basic flaw with biometrics (that once compromised they cannot be changed) is still a real problem, whether you compare it to a parachute, an anvil or whatever. I don't see how you can find away around such a fundamental flaw, even if you do start implementing it. Or have I missed advances in retina transplant technology?
Ofcourse people will be able to make fake prints or find ways to circumvent the biometric system. But, what system is fully flawless? The best thing to do would be to start using biometrics without 100% reliance on them till we are confident enough and experienced enough to stay ahead of the criminals in preventing misuse. Transition will be a pain for some time, but once the system has established itself, it will make our lives much easier.
Not a good argument. Listen, people can't fly, but let's jump off the nearest 10-story building, and we'll learn how to fly on the way down. I mean, the advantages of being able to fly must outweigh any conceivable drawbacks, no?
The flaw with your argument is that biometric identifiers, once compromised, cannot be changed. What happens if you get your fingerprints lifted? A finger transplant? No, at that point your only choice is to have some sort of fraud alert put on your fingerprint, and then you can no longer use it. So it's useless for you, forever. If you'd read the article you'd see that the authors complained that they discovered critical flaws in fingerprint readers ten years ago, including that they could be fooled using fake gelatin fingers, and they still haven't fixed that. You think Microsoft is bad, leaving IIS unpatched for three months? Try ten years... The only conclusion is that the readers can't be fixed.
Blind adoption of some shiny new technology without at least some foresight is too common, and really, really stupid. Electronic voting is another great example of this...
In the trade between freedom and security (which isn't necessarily a trade, by the way), wouldn't it be better if the default was freedom? If you want security you are free to arm yourself to the teeth and wall yourself off in your Own Private castle (Idaho?), giving up your freedom in return for security. Let me be, so I can choose freedom. If the default is security, then there IS no freedom.
And don't give me that shit about nukes killing everyone. As long as the nuclear powers keep track of their warheads, and we keep a decent watch out for enriched Uranium at the borders the risk is pretty damned small. I've studied nuclear physics, and Mohammed Atta wasn't that close to a nuke, believe me. I'd be more worried about an asteroid impact. Or a wildfire.
You can quote dead white men all you like, but it doesn't change the fact that in the past two hundred odd years society has changed significantly and a single individual's ability to wreak widespread havoc has been increased million-fold.
You're basically saying that the Bill of Rights is obsolete? I beg to differ. I think it has worked a damned sight better, for a lot longer, than pretty much any other government structure you care to name. Now is not the time to shred it. And you forget; it has always been possible for a single individual to cause enormous widespread havoc, killing thousands or even millions. Usually that is done by seizing the power of the government and starting a war. Part of the reason we have a Constitution with checks and balances is so that a single individual can't cause all that death.
So the destructive potential of an individual hasn't increased, it has just changed form a bit. But the old way is still alive and as dangerous as always.
Of course - A judge still has to ok the jaywalker or abortionist to be a terrorist
Yes. A special judge, hand-picked by the Justice department, who is part of a secret court that apparently hasn't turned down a single warrant request, ever. The one time they did another secret appeals court was conviened and granted the request.
The idea of relying on a judge to determine "probable cause" only works if there is a check-and-balance, i.e. if the judge is a public figure subject to public scrutiny, which these aren't.
Then there is this B.S. where the prez can label anyone - even an American citizen - an "enemy combatant" and summarily remove ALL his rights.
Where the hell is due process in that? Some guy can single-handedly say that the Bill of Rights doesn't apply to you? No appeals, and off to the brig you go. WTF!?
In many socialist democracies like most of Europe and to an extent here, the minority is routinely ignored.
Having lived in Europe I would have to disagree. These governments tend to be parlamentarian, which means power is gained by building coalitions. In such a situation a small swing-vote minority can hold disproportionate power. The Greens did it in Germany and Sweden among other places. Israel is full of such parties.
How else can the leftists succeeed?
I'm not sure where you're going with this. If we assume that "the leftists" are in power in Europe (true most places), and if we assume that the majority in Europe is leftist (a fair assumption), and we assume that the minority righ wingers tend to have more money (also a fair assumption) then a) it proves my point - i.e. votes are more important than money. b) The majority rules, within reasonable limits.
c) The minority has rights. Among others, the right to keep their money. Else they wouldn't be richer than everyone else.
If it wasn't pure majority over civil rights, how could Social Security exist? (the majority voting for generational debt at the cost of fundamental property rights for the yet-to-be-born.)
Slow down there cowboy. Where in the Constitution does it say that the unborn have rights? They are (hopefully) not a minority, but they are totally disenfranchised. That's part of the problem now. If the unborn could vote you can bet your last dollar (or vote?) that they would be all for a high gas tax.
It really boils down to this: you can lose all your money. In a functioning constitutional democracy you can't lose all your rights. (Yeah, I know. Gitmo. PATRIOT act, "enemy combattants". That's a point you should have made).
No, the minority is not worthless. Citizens have rights that can't be taken away by the majority. I said that in my post.
Not everyone who works has money that they can spend freely. They have to spend it on food, housing, health care etc. There isn't always a lot of choice (and hence power) in the lower economic classes. Even among the working poor. Oh, by the way, there are people out in the world who can't work. The very young. The very old. The infirm.
Every economic class has powers unique to their economic niche
That's pretty classic. I guess poor people really have a lot of control over Wal-Mart, eh? But how much of that is real power, righty? When Bill Gates has more money than the poorest ten million people in the country, how would they win a power struggle? By voting. Not by trying to boycott PC's which they can't afford to buy anyway.
That is the problem: we have given up the most powerful feature an individual has: the power to vote with one's dollar.
Gee. I would have though the most important thing we had was the right to VOTE. Followed closely by certain rights to not be harassed by the tyranny of the majority.
The right to vote with ones' dollar means very little when you have fewer dollars than the guy who is out to screw you.
You're right. The problem I think we have here is that there is no clear danger-wielding NEED for alternative energy sources right no. We're not near environmental collapse (even if global warming were true, which it's not). The cost of fossil fuels is still low enough that people are willing to pay it.
Governments can artificially make things more attractive (electric cars for example), but in the long run, it's going to take something big to happen before these new energy sources reach critical mass.
Oh, where to start on this one... let's see. Best estimates talk about oil lasting another 40-80 years at most. Given how basic oil is to our economy, and how long it takes to replace the oil infrastructure, it's necessary to start well in advance of when we actually run out. It takes TIME to develop fuel cells, fusion, hydrogen, or pig-shit based energy sources. The fact of the matter is that current market mechanisms do not do a good job of accounting for the future. They do not accurately price things ten, twenty or 40 years into the future. There is simply too much uncertainty for small companies to accurately gauge the value of investment in the very long term. That's one point.
A related point: people say "leave it to the market". Some invisible hand will reach out and save things and we don't have to do anything. I got news for ya folks. The markets are not ideal or perfect. They fail to account for costs, they do not predict future events, they can be manipulated. So don't put your future in blind trust of the market.
Next point. Global warming. It is real.
Half the scientists in my department work on that area, and they all pretty much say "don't buy seafront property". I'll take the word of the National Academy of Sciences over your say-so any day.
Final point, in response to both your post and the parent posts. Don't belive the ultra-libertarian crap. There is a time and place for government intervention. It's when you have a chicken-and-egg problem: private investment won't happen until there is a reliable demand. Demand won't happen until there has been private investement. There are plenty of examples where government intervention and subsidies have worked very well. The interstate highway system. Rural electrification. Nuclear power. The airline industry (how it got started). The Internet.
Actually, Iraq has about 120 billion barrels of oil in known reserves. At a market price of $30/barrel and and extraction cost of maybe $5/barrel, we're definitely talking a lot of money in the ground. True, the U.S. will probably spend something like half a trillion dollars on the war, and the oil revenue won't go to the U.S Treasury (it might go to ChevronTexaco, though). But the issue is not just about ensuring access to oil for the U.S., it's about preventing other countries from gaining that access (Europe & China primarily). Whoever has access to the cheapest, most abundant energy will have the stongest economy and so be in a position to boss everybody else around. It's simple realpolitik.
That's why you're seeing a conscious effort to diversify America's oil imports. South America is a huge and growing source, as is Africa and Russia. While Saudi Arabia is still the biggest player in the game, they are not as dominant as they once were.
The problem is that the vast majority of known oil reserves are in the Middle East. We can diversify all we please, but where there ain't no oil, there ain't no oil. It's not a coincidence that the U.S. has troops in 4 out of the top 5 countries with the largest oil reserves.
What I find interesting is this: the known oil reserves add up to about 831 billion barrels. Current world consumption is about 60 million barrels a day. At current rates that's 40 years, folks. Of course, new oil is sometimes discovered. But consumption grows at an annual rate of a few percent. We will likely see the end of oil in our lifetimes. That's kinda scary, actually.
All that BS about fuels cells and hydrogen sounds nice, but where is the energy source? Coal? Hot air from politicians?
It's extremely unlikely that NASA would want to put an un-proven, unmanned vehicle anywhere near the ISS. The risk of collision is too great. The Russians do it with their Progress vehicles and modules (I forget the name), but they took many years to develop, and they've had accidents. The Europeans are busy developing an autonomous transfer vehicle, but being Europeans (who care even less about space funding than Congress does) they might get something up in 5-6 years. Nothing sooner.
The U.S. doesn't currently have a vehicle suitable for unmanned formation flight and docking, and it would take years and gigabucks to develop. Hell, with the retirement of the Titan IV and delays in the EELV we don't even have a heavy-lift capability. Sure, we could do it. We can do a lot of things. But it takes money that is currently going down an Iraqi rat-hole. So get used to the idea of seeing ISS re-enter Mir-style in a few years. Remember, we ditched Skylab in the 70's. It was a fully functional space station with a larger volume than ISS. We've screwed up before - we'll no doubt do it again.
You are wrong in one point of your vision... it is not a world _without_ possession, it is a world, where a _few people posses everything_ and the majority of people are just granted a few rights.
Uhm... hey it is quite close to the world we are already living, 10% of the people posses 90% of all property.
And so we've come full circle. In the middle ages the landed gentry owned the "means of production"(i.e. all the land), while the peasants eked out a living at their mercy. In early industrial times it was the factory owners who owned said means, and the workers were terribly exploited (that pretty much still is the case in many developing countries). Then there was Communism, where the state did the exploiting.
What we are witnessing now is a mad grab for the modern means of production - knowledge. "Intellectual property".
You made one mistake though - the majority are not granted a few rights. They may be told they have certain inalienable rights; but when living in a company town, eating company food, and relying on company health care, what rights and how much freedom do you really have? Can you speak out against corrupt managment wiithout losing everything? Can you move elsewhere when working conditions are dangerous (if you have no startup capital, no equity in your house, own nothing of value or cannnot resell what you do have, and need a good letter of reference in a tight labor market. And assuming things are better anywhere else..)?.
Welcome to anarcho-Capitalist heaven; where a few people own everybody else.
You certainly have a good point. But it's more complicated than that. People fall into group-think. People's thought patterns get stuck in a groove and discrepant information gets ignored. People pre-filter information based on experience that may or may not be appropriate. People are just plain dumb. Or too harried to think straight. Or they perceive that they are between a rock and a hard place and just elect to take a risk. Sometimes those risks pay off, sometimes you get clobbered. With the Shuttle it was a little of each.
This spate about the ISS is different. You have to understand that without the Shuttle there is a tremendous squeeze on available mass transfer (up or down). There are dozens of groups that all want space for THEIR particular widget, and it's the squeeky wheel that gets the grease. The life support guys have had to give up some of their allotment and they figure that by going public they can pressure NASA managment into giving them what they need.
The problem isn't really NASA managment, or bad design. It's that a) Congress and the President don't give a shit about NASA and hence b) there is insufficient funding for a robust program (with more that one 20-year old launch system).
Something else to know; the Russians have been shouldering the entire burden of maintaining ISS WITHOUT any extra funding from the U.S. They' have had to fly several more of their Progress vehicles than they had budgeted for. At $20 million a pop, and a total budget of $200 million, that is quite a burden. NASA is not allowed to transfer funding to the Russians because we accuse them of helping the Iranians with missle and nuclear technology (yes, there is such a law).
It's a big mess. A cluster-fuck to be exact. Makes me very sad.
We're still burning fossil fuels because they're cheaper. Without regulations that force companies to pay for the pollution they generate, fossil fuels will always be cheaper than other forms of energy.
Pretty true, yeah. The price of gas doesn't include the cost of the associated pollution, the cost of keeping troops in the Middle East to ensure that oil supply etc... In addition, things like the Interstate system are a huge subsidy to the car and oil industries, because fewer people would drive if they had to pay tolls, and oil price might reflect that (in the case where there is essentially a volumne discount to oil).
Nuclear energy is barely cost competitive now, and the only reason they are even close to competive is because of the heavy government subsidies that the industry gets.
That's actually not true. The nuclear industry is not particularly subsidized in the U.S., and you could argue that some of the excessive controls make it more expecnsive than it should be. I'm not arguing that nukes should be free to pollute - but I am saying that they are held to standards that are ridiculously tight. For instance, because it contains small amounts of natural radioactivity, coal ash would be considered low to medium level nuclear waste if it came from a nuke plant. Of course, coal plants can pretty much just dump it. The amount of money and paperwork the nukes have to go through to do ANYTHING is cost-prohibitive.
You might want to note that between 15 and 20% of all the electricity generated in the U.S. comes from nuke plants, and there have been no new plants built in almost 30 years. The fact that these old systems are still in such use should tell you that they are actually a competetive source of power.
it is specifically designed not to be able to go supercritical and create a self sustaining reaction.
I'm sorry, but that is not correct. They are talking about a reactor, not a radio-isotope generator. ANY reactor has to go supercritical in order to increase its power level. That's how you increase power in a reactor. What this design won't do is go "prompt critical". The difference is nit-picky, but very important and rather interesting. Bear with me.
A fission chain reaction works because when a neutron hits a uranium nucleus, it splits it. The uranium nucleus releases energy and more neutrons. There are two kinds that get released: about 98.5% are "prompt neutrons" and are released in a picosecond. The remaining "delayed neutrons" come out a fraction of a second later. In order for the reaction to be self-sutaining you need to produce as many neutrons as are consumed by the fission (and absorbtion, leakage etc). If the two are balanced your reactor is "critical". If you have more neutrons you are supercritical and your power level increases exponentially, with a time constant given by the neutron generation time. "Prompt critical" means that you have enough neutrons that even just the prompt ones are enough to be supercritical. In that case the doubling time is measured in picoseconds - which is impossible to control and may cause an explosion. The upshot is that you want to avoid being prompt critical, but you cannot get power unless you go supercritical on delayed neutrons. (In the latter case your power level increases in a controllable fashion. When you have the power level you want you drop the control rods or somthing similar to lower the reactivity (i.e. change the neutron balance)).
There have been several accidents in which the reactor inadvertently went prompt critical (including the Idaho one). However, by careful design you can avoid this problem, which is what the Toshiba design does. It is not the only accident pathway however.
The Toshiba reactor sounds like a fairly safe design, what with using natural convection and very simple neutron reflectors for control. The latter is by no means a new idea - it's been used by most breeder reactors for decades.
However, it's not necessarily idiot proof. The liquid sodium coolant is in my opinion a bad design choice. They should use liquid lead instead. It's been done by the Russians, and works well as long as you know what you are doing, and lead isn't explosive in contact with water the way sodium is.
The idea of small, low-maintenance nuclear plants for remote sites is not really that good. The biggest problem is that you wouldn't want, say, North Korea, to have one - they are excellent neutron sources and as such can be used to make plutonium. A design with hundreds of small units scattered all over the place makes for difficulties in controlling their use. Also, it doesn't matter how well you design against internal accidents (operator error, equipment failure etc); it's very difficult to protect against terrorism, particularly for a small reactor. It is feasible to surround a 1000 MW plant with guards and antiaircraft missles, but not really for a 10MW plant. This means it's more likely someone will be able to gain access to one of these things, blow it up, and possibly cause radioactive release. Yes, you could haul in enough C4 to blow up the reactor tank and cause a sodium/water fire that would be very difficut to contain. Despite their claim the sodium IS radioactive (activated by the neutrons flying around everywhere). Very bad from a PR perspective if nothing else.
For the record I think nuclear power is just about our only hope for a sustainable future. But that doesn't mean I'm enthusiastic about every nuclear scheme people can dream up.
IF DEVICE BECOMES OVERLY WARM, IMMERSE IMMEDIATELY IN HEAVY WATER AND CALL THE U.S. ENVIRONMENTAL PROTECTION AGENCY'S RADIOLOGICAL EMERGENCY RESPONSE TEAM.
Immersing it in heavy water is the last thing you want to do. Heavy water slows down ("moderates") the neutrons, making the fission reactions go faster... No, immerse it in borated, light water.
near-instantaneous, gravity-free and truly surgical, focusing to such hair-splitting accuracy that it could avoid civilians while predetonating munitions miles away - perhaps someday even being mounted on Humvees.
Unfortunately, a laser can scatter off of almost any surface and blind people at distances of miles. It's impossible to predict which way the scatter may go, so we're talking about the likelihood of blinding civilians...
It is against the Geneva convention to use weapons that intentionally or predominantly blind adversaries; so use of this may well be a war crime. Not that we've cared much about leglities recently...
So true! The true innovation of the jet engine was not that it was faster. It was because it reduced vibration as compared to props and was more efficient. Faster was merely a side benefit.
No. So, so wrong. Props are more "efficient" in terms of fuel efficiency. That's why they still make turboprops. Jet engines are used for many reasons, but primarily because they provide a higher maximum thrust in a smaller package and they work better at high speed and altitude. It very much has to do with speed. A prop cannot go supersonic - a jet can.
Is it really fair to call it technological regression? There's more to flight than raw speed. The Concordes were notoriously inefficient. I think an argument can be made that some of Boeing's latest offerings are technologically more advanced.
Yes it is fair to call it regression. I think that every time I'm sitting with my legs cramped up into my chin for 9 hours on a flight that could take 3. There may be more to flight than raw speed, but I'm not sure what that would be.
Sure the latest Boeing sardine tube has really advanced in-flight movie players (which are broken half the time), but that doesn't make it a better plane.
It think it's beyond argument that there has recently been a loss of technological capability in certain areas. Supersonic flight is one.
Related to that is a loss of good engineering talent in the areas of aerodynamics, propulsion and vehicle design (witness recent NASA embarassments in the X38 etc). Spaceflight is another area of loss - we couldn't get to the Moon now even if we wanted to. We also can no longer lift as much into orbit as we once could.
Nuclear power is another area. There has been a tremendous loss in engineering know-how when it comes to reactor design; this is something that will no doubt be sorely missed in the not too distant future.
The saddest part is that many people have convinced themselves that the loss doesn't matter, that these things aren't important. That's a damned shame. We need to develop better means of energy generation, high-speed transport, and space access if we are to have a livable planet with 10 billion people on it.
Note, I'm not disputing that there have been tremendous advances in other areas (information technoogy, obviously). I'm just saying that it isn't uninterrupted progress everywhere you look.
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Perhaps. But why isn't there life on the Moon? Not possible, right? It may well be that life in space is just not possible. I can tell you this, the energetics of space travel are such that unless we master nuclear energy (fusion, actually), we won't get very far.
You compare space travel to the new world, but there is a big difference. If you're a settler in Lousiana you can still live and procreate with no technology. You can't do that on the moon if your life support fails. A better Earth-bound analogy is the oceans (above or below the surface); and despite that horrible Kevin Kostner movie, we haven't colonized the oceans. We travel across them, yes, but we don't live there.
But your comment reminded me of an interesting question - Fermi's paradox. If life is able to traverse interstellar distances, even limited to sublight, why isn't the Galaxy swarming? Or more to the point, why aren't they here? It doesn't take many generations of exponential growth to fill a galaxy, and ten billion years is a long time for life to start, develop interstellar travel, and start expanding. Given that stars are usually no more than a few light-years apart, you could imagine that you could send out colonies, that in turn sent out further colonies with a generational time of a few hundred years. In a few million years you have the Galaxy. There aren't very many possible answers: a) interstellar travel is impossible, b) we're unique, c) they're already here or d) they're on their way. Options b) and d) are statistically extremely unlikely. (I vote for c! :)
Well, a factor of 20 in strength is a factor of twenty, and you have a factor of 10,000,000 to go in length. I mean, all we need to make a good single-stage-to-orbit vehicle with current materials is a rocket with a specific impulse of ~1000 (from the rocket equation. With and Isp of 1000 you can make your vehicle out of cast iron and still make orbit). The Shuttle has an Isp of 455 - so it's only a factor of two off. Must be easy, right? My point is that "almost there" can be the same as "not there". (If you aren't up on your propulsion physics, there is no way in hell you can get a chemical rocket with an Isp of 1000. Not enough chemical energy in the bonds.).
I'm not saying beanstalks are impossible. I'm just saying that it's a bit too early to plan your vacation on Mars. I'd love it if I saw one in my lifetime, but I doubt I will. And I'm not that old.
People running around claiming these things are just around the corner are a) bound to be disappointed, b) will end up causing a backlash in the general public when the promises fail to appear (ask Joe Schmoe about flying cars, or electricity too cheap to meter, or vacations on the Moon. Now ask him for his tax dollars so you can develop this fancy new form of space travel. Good luck!)
Please provide a reference. I'd love to see progress with nanotubes. Of course, if they really are making macroscopic lengths of nanotube then there are plenty of applications - high-strength composites come to mind. But I' am far from convinced that that has actually been done. Let's see the first suspension bridge made from carbon nanotubes before we start talking about beanstalks.
The spacedebris problem was solved years ago, +10 cm and larger pieces will be detected by ground radars and avoided by a movable tether, the same for sattelites obviously. Smaller then 10cm debris isn't a very serious threat for the tether.
If you define "solved" as some guy claiming it can be done based on no solid analysis. Tether dynamics are notoriously difficult to manage, and I doubt that you could actually get the tether where you wanted it. I can flat-out guarantee that it's not "solved", just that we maybe have an inkling of where to start. Also, do not discount the kinetic energy in a 9-cm chunk of debris travelling at 10 km/s. It WILL punch through a tether; I guess you can have a lattice of multiple tethers or something, but again, it's not exactly solved.
As for slippage, I don't know about that. But I figure if I could make a nanotube as long as the entire lift length it'll become irrelevant anyway.
Well, no, because you have to repair the tether, splice in new pieces, etc etc. As for those Chinese guys - reference please. There is again a big difference between fusing together a few microns worth of nanotubes and making a string 40,000 km in length. And nanotubes are about as slippery as graphite (a very good lube, except for in certain applications :). It'll be hard to braid the tether, and it'll be hard to climb up it.
there are already materials that are hard to get here on earth, and can be found in abundance in space.
Name a few where the price exceeds $10,000/kg and there is a demand for more than a few kg. (Plutonium doesn't count!) Remember, if you are willing to spend 20-200 G$ on initial investment, you have to consider if the same elements can be obtained on the ground for even a fraction of such an enormous investment (ocean mining anyone?).
Look, I don't mean to piss in everyones beer, but in my experience the community of space enthusiasts suffers from a lack of realistic thinking. People are talking about beanstalks when we can hardly get a few guys into low Earth orbit, let alone past the Moon. I think we need to keep the dream alive, but the best way to do that is to get your various governments to spend the G$ needed to bootstrap spacetravel into viability. And despite what you think, governments have access to very sharp people who do think critically about these things and have tremendous engineering talent and experience. They won't be swayed by poorly thought-out ideas or wishful thinking. And yes, it has to be governments, as they are the only organizations that have the astronomical quantities of cash that we are talking about. The USA can drop $8.7e10 in one year to clean up daddys mess (let's not get started on that one!); what company can do the same? (hell, if you stacked $87B in dollar bills it would reach almost to geosync. THAT's pretty mind-boggling.)
I wish I still had my youthful enthusiasm, but having seen Mir re-enter, the Concorde retired, the Shuttle explode twice, and the level of apathy in the American public, I just don't see it happening. Sorry.
A space elevator ("beanstalk") is very far off, regardless of the hype. Even if they could make carbon nanotube strands longer than 10 microns, and even if they could braid them in a fashion where they wouldn't slip, they'd still have to launch a few thousand tons worth of stuff into geosynch orbit. And then they'd have to figure out how to avoid getting the tether cut by space debris... If I see it in my lifetime I'll die a happy man.
Look, space mining and space development in general is a great idea. It just won't happen - there is too much of a chicken-and-egg problem. Someday maybe, when we need He3 and we've figured out how to make a good tether, and we've found a high specific-impulse engine, then perhaps it'll happen. But like I said, don't hold your breath.
The materials (iron, rare earths, iridium, nickel) that you could bring back simply do not command prices high enough to make it worthwhile - they're in the few dollars to few hundred dollars/kg range.
This might change IF someone invented fusion that worked, and required He3. Then it might be worth it. Don't call me until that happens... and don't hold your breath, either.
The basic flaw with biometrics (that once compromised they cannot be changed) is still a real problem, whether you compare it to a parachute, an anvil or whatever. I don't see how you can find away around such a fundamental flaw, even if you do start implementing it. Or have I missed advances in retina transplant technology?
Not a good argument. Listen, people can't fly, but let's jump off the nearest 10-story building, and we'll learn how to fly on the way down. I mean, the advantages of being able to fly must outweigh any conceivable drawbacks, no?
The flaw with your argument is that biometric identifiers, once compromised, cannot be changed. What happens if you get your fingerprints lifted? A finger transplant? No, at that point your only choice is to have some sort of fraud alert put on your fingerprint, and then you can no longer use it. So it's useless for you, forever. If you'd read the article you'd see that the authors complained that they discovered critical flaws in fingerprint readers ten years ago, including that they could be fooled using fake gelatin fingers, and they still haven't fixed that. You think Microsoft is bad, leaving IIS unpatched for three months? Try ten years... The only conclusion is that the readers can't be fixed.
Blind adoption of some shiny new technology without at least some foresight is too common, and really, really stupid. Electronic voting is another great example of this...
I thought it had been shown that to make a quantum computer you needed the gates to be made of cats...
That's even better. Why the hell have a judge? Why not just have the court clerk administer the rubber stamp...?
And don't give me that shit about nukes killing everyone. As long as the nuclear powers keep track of their warheads, and we keep a decent watch out for enriched Uranium at the borders the risk is pretty damned small. I've studied nuclear physics, and Mohammed Atta wasn't that close to a nuke, believe me. I'd be more worried about an asteroid impact. Or a wildfire.
You can quote dead white men all you like, but it doesn't change the fact that in the past two hundred odd years society has changed significantly and a single individual's ability to wreak widespread havoc has been increased million-fold.
You're basically saying that the Bill of Rights is obsolete? I beg to differ. I think it has worked a damned sight better, for a lot longer, than pretty much any other government structure you care to name. Now is not the time to shred it. And you forget; it has always been possible for a single individual to cause enormous widespread havoc, killing thousands or even millions. Usually that is done by seizing the power of the government and starting a war. Part of the reason we have a Constitution with checks and balances is so that a single individual can't cause all that death. So the destructive potential of an individual hasn't increased, it has just changed form a bit. But the old way is still alive and as dangerous as always.
Yes. A special judge, hand-picked by the Justice department, who is part of a secret court that apparently hasn't turned down a single warrant request, ever. The one time they did another secret appeals court was conviened and granted the request.
The idea of relying on a judge to determine "probable cause" only works if there is a check-and-balance, i.e. if the judge is a public figure subject to public scrutiny, which these aren't.
Then there is this B.S. where the prez can label anyone - even an American citizen - an "enemy combatant" and summarily remove ALL his rights. Where the hell is due process in that? Some guy can single-handedly say that the Bill of Rights doesn't apply to you? No appeals, and off to the brig you go. WTF!?
Having lived in Europe I would have to disagree. These governments tend to be parlamentarian, which means power is gained by building coalitions. In such a situation a small swing-vote minority can hold disproportionate power. The Greens did it in Germany and Sweden among other places. Israel is full of such parties.
How else can the leftists succeeed?
I'm not sure where you're going with this. If we assume that "the leftists" are in power in Europe (true most places), and if we assume that the majority in Europe is leftist (a fair assumption), and we assume that the minority righ wingers tend to have more money (also a fair assumption) then a) it proves my point - i.e. votes are more important than money. b) The majority rules, within reasonable limits. c) The minority has rights. Among others, the right to keep their money. Else they wouldn't be richer than everyone else.
If it wasn't pure majority over civil rights, how could Social Security exist? (the majority voting for generational debt at the cost of fundamental property rights for the yet-to-be-born.)
Slow down there cowboy. Where in the Constitution does it say that the unborn have rights? They are (hopefully) not a minority, but they are totally disenfranchised. That's part of the problem now. If the unborn could vote you can bet your last dollar (or vote?) that they would be all for a high gas tax.
It really boils down to this: you can lose all your money. In a functioning constitutional democracy you can't lose all your rights. (Yeah, I know. Gitmo. PATRIOT act, "enemy combattants". That's a point you should have made).
Not everyone who works has money that they can spend freely. They have to spend it on food, housing, health care etc. There isn't always a lot of choice (and hence power) in the lower economic classes. Even among the working poor. Oh, by the way, there are people out in the world who can't work. The very young. The very old. The infirm.
Every economic class has powers unique to their economic niche
That's pretty classic. I guess poor people really have a lot of control over Wal-Mart, eh? But how much of that is real power, righty? When Bill Gates has more money than the poorest ten million people in the country, how would they win a power struggle? By voting. Not by trying to boycott PC's which they can't afford to buy anyway.
Gee. I would have though the most important thing we had was the right to VOTE. Followed closely by certain rights to not be harassed by the tyranny of the majority.
The right to vote with ones' dollar means very little when you have fewer dollars than the guy who is out to screw you.
Oh, where to start on this one... let's see. Best estimates talk about oil lasting another 40-80 years at most. Given how basic oil is to our economy, and how long it takes to replace the oil infrastructure, it's necessary to start well in advance of when we actually run out. It takes TIME to develop fuel cells, fusion, hydrogen, or pig-shit based energy sources. The fact of the matter is that current market mechanisms do not do a good job of accounting for the future. They do not accurately price things ten, twenty or 40 years into the future. There is simply too much uncertainty for small companies to accurately gauge the value of investment in the very long term. That's one point.
A related point: people say "leave it to the market". Some invisible hand will reach out and save things and we don't have to do anything. I got news for ya folks. The markets are not ideal or perfect. They fail to account for costs, they do not predict future events, they can be manipulated. So don't put your future in blind trust of the market.
Next point. Global warming. It is real. Half the scientists in my department work on that area, and they all pretty much say "don't buy seafront property". I'll take the word of the National Academy of Sciences over your say-so any day.
Final point, in response to both your post and the parent posts. Don't belive the ultra-libertarian crap. There is a time and place for government intervention. It's when you have a chicken-and-egg problem: private investment won't happen until there is a reliable demand. Demand won't happen until there has been private investement. There are plenty of examples where government intervention and subsidies have worked very well. The interstate highway system. Rural electrification. Nuclear power. The airline industry (how it got started). The Internet.
The problem is that the vast majority of known oil reserves are in the Middle East. We can diversify all we please, but where there ain't no oil, there ain't no oil. It's not a coincidence that the U.S. has troops in 4 out of the top 5 countries with the largest oil reserves.
What I find interesting is this: the known oil reserves add up to about 831 billion barrels. Current world consumption is about 60 million barrels a day. At current rates that's 40 years, folks. Of course, new oil is sometimes discovered. But consumption grows at an annual rate of a few percent. We will likely see the end of oil in our lifetimes. That's kinda scary, actually.
All that BS about fuels cells and hydrogen sounds nice, but where is the energy source? Coal? Hot air from politicians?
The U.S. doesn't currently have a vehicle suitable for unmanned formation flight and docking, and it would take years and gigabucks to develop. Hell, with the retirement of the Titan IV and delays in the EELV we don't even have a heavy-lift capability. Sure, we could do it. We can do a lot of things. But it takes money that is currently going down an Iraqi rat-hole. So get used to the idea of seeing ISS re-enter Mir-style in a few years. Remember, we ditched Skylab in the 70's. It was a fully functional space station with a larger volume than ISS. We've screwed up before - we'll no doubt do it again.
And so we've come full circle. In the middle ages the landed gentry owned the "means of production"(i.e. all the land), while the peasants eked out a living at their mercy. In early industrial times it was the factory owners who owned said means, and the workers were terribly exploited (that pretty much still is the case in many developing countries). Then there was Communism, where the state did the exploiting. What we are witnessing now is a mad grab for the modern means of production - knowledge. "Intellectual property".
You made one mistake though - the majority are not granted a few rights. They may be told they have certain inalienable rights; but when living in a company town, eating company food, and relying on company health care, what rights and how much freedom do you really have? Can you speak out against corrupt managment wiithout losing everything? Can you move elsewhere when working conditions are dangerous (if you have no startup capital, no equity in your house, own nothing of value or cannnot resell what you do have, and need a good letter of reference in a tight labor market. And assuming things are better anywhere else..)?.
Welcome to anarcho-Capitalist heaven; where a few people own everybody else.
This spate about the ISS is different. You have to understand that without the Shuttle there is a tremendous squeeze on available mass transfer (up or down). There are dozens of groups that all want space for THEIR particular widget, and it's the squeeky wheel that gets the grease. The life support guys have had to give up some of their allotment and they figure that by going public they can pressure NASA managment into giving them what they need.
The problem isn't really NASA managment, or bad design. It's that a) Congress and the President don't give a shit about NASA and hence b) there is insufficient funding for a robust program (with more that one 20-year old launch system).
Something else to know; the Russians have been shouldering the entire burden of maintaining ISS WITHOUT any extra funding from the U.S. They' have had to fly several more of their Progress vehicles than they had budgeted for. At $20 million a pop, and a total budget of $200 million, that is quite a burden. NASA is not allowed to transfer funding to the Russians because we accuse them of helping the Iranians with missle and nuclear technology (yes, there is such a law). It's a big mess. A cluster-fuck to be exact. Makes me very sad.
Pretty true, yeah. The price of gas doesn't include the cost of the associated pollution, the cost of keeping troops in the Middle East to ensure that oil supply etc... In addition, things like the Interstate system are a huge subsidy to the car and oil industries, because fewer people would drive if they had to pay tolls, and oil price might reflect that (in the case where there is essentially a volumne discount to oil).
Nuclear energy is barely cost competitive now, and the only reason they are even close to competive is because of the heavy government subsidies that the industry gets.
That's actually not true. The nuclear industry is not particularly subsidized in the U.S., and you could argue that some of the excessive controls make it more expecnsive than it should be. I'm not arguing that nukes should be free to pollute - but I am saying that they are held to standards that are ridiculously tight. For instance, because it contains small amounts of natural radioactivity, coal ash would be considered low to medium level nuclear waste if it came from a nuke plant. Of course, coal plants can pretty much just dump it. The amount of money and paperwork the nukes have to go through to do ANYTHING is cost-prohibitive.
You might want to note that between 15 and 20% of all the electricity generated in the U.S. comes from nuke plants, and there have been no new plants built in almost 30 years. The fact that these old systems are still in such use should tell you that they are actually a competetive source of power.
I'm sorry, but that is not correct. They are talking about a reactor, not a radio-isotope generator. ANY reactor has to go supercritical in order to increase its power level. That's how you increase power in a reactor. What this design won't do is go "prompt critical". The difference is nit-picky, but very important and rather interesting. Bear with me.
A fission chain reaction works because when a neutron hits a uranium nucleus, it splits it. The uranium nucleus releases energy and more neutrons. There are two kinds that get released: about 98.5% are "prompt neutrons" and are released in a picosecond. The remaining "delayed neutrons" come out a fraction of a second later. In order for the reaction to be self-sutaining you need to produce as many neutrons as are consumed by the fission (and absorbtion, leakage etc). If the two are balanced your reactor is "critical". If you have more neutrons you are supercritical and your power level increases exponentially, with a time constant given by the neutron generation time. "Prompt critical" means that you have enough neutrons that even just the prompt ones are enough to be supercritical. In that case the doubling time is measured in picoseconds - which is impossible to control and may cause an explosion. The upshot is that you want to avoid being prompt critical, but you cannot get power unless you go supercritical on delayed neutrons. (In the latter case your power level increases in a controllable fashion. When you have the power level you want you drop the control rods or somthing similar to lower the reactivity (i.e. change the neutron balance)).
There have been several accidents in which the reactor inadvertently went prompt critical (including the Idaho one). However, by careful design you can avoid this problem, which is what the Toshiba design does. It is not the only accident pathway however.
The Toshiba reactor sounds like a fairly safe design, what with using natural convection and very simple neutron reflectors for control. The latter is by no means a new idea - it's been used by most breeder reactors for decades. However, it's not necessarily idiot proof. The liquid sodium coolant is in my opinion a bad design choice. They should use liquid lead instead. It's been done by the Russians, and works well as long as you know what you are doing, and lead isn't explosive in contact with water the way sodium is.
The idea of small, low-maintenance nuclear plants for remote sites is not really that good. The biggest problem is that you wouldn't want, say, North Korea, to have one - they are excellent neutron sources and as such can be used to make plutonium. A design with hundreds of small units scattered all over the place makes for difficulties in controlling their use. Also, it doesn't matter how well you design against internal accidents (operator error, equipment failure etc); it's very difficult to protect against terrorism, particularly for a small reactor. It is feasible to surround a 1000 MW plant with guards and antiaircraft missles, but not really for a 10MW plant. This means it's more likely someone will be able to gain access to one of these things, blow it up, and possibly cause radioactive release. Yes, you could haul in enough C4 to blow up the reactor tank and cause a sodium/water fire that would be very difficut to contain. Despite their claim the sodium IS radioactive (activated by the neutrons flying around everywhere). Very bad from a PR perspective if nothing else.
For the record I think nuclear power is just about our only hope for a sustainable future. But that doesn't mean I'm enthusiastic about every nuclear scheme people can dream up.
Immersing it in heavy water is the last thing you want to do. Heavy water slows down ("moderates") the neutrons, making the fission reactions go faster... No, immerse it in borated, light water.
But the rest of the comment is funny. :)
Unfortunately, a laser can scatter off of almost any surface and blind people at distances of miles. It's impossible to predict which way the scatter may go, so we're talking about the likelihood of blinding civilians...
It is against the Geneva convention to use weapons that intentionally or predominantly blind adversaries; so use of this may well be a war crime. Not that we've cared much about leglities recently...
No. So, so wrong. Props are more "efficient" in terms of fuel efficiency. That's why they still make turboprops. Jet engines are used for many reasons, but primarily because they provide a higher maximum thrust in a smaller package and they work better at high speed and altitude. It very much has to do with speed. A prop cannot go supersonic - a jet can.
Is it really fair to call it technological regression? There's more to flight than raw speed. The Concordes were notoriously inefficient. I think an argument can be made that some of Boeing's latest offerings are technologically more advanced.
Yes it is fair to call it regression. I think that every time I'm sitting with my legs cramped up into my chin for 9 hours on a flight that could take 3. There may be more to flight than raw speed, but I'm not sure what that would be. Sure the latest Boeing sardine tube has really advanced in-flight movie players (which are broken half the time), but that doesn't make it a better plane.
It think it's beyond argument that there has recently been a loss of technological capability in certain areas. Supersonic flight is one. Related to that is a loss of good engineering talent in the areas of aerodynamics, propulsion and vehicle design (witness recent NASA embarassments in the X38 etc). Spaceflight is another area of loss - we couldn't get to the Moon now even if we wanted to. We also can no longer lift as much into orbit as we once could. Nuclear power is another area. There has been a tremendous loss in engineering know-how when it comes to reactor design; this is something that will no doubt be sorely missed in the not too distant future.
The saddest part is that many people have convinced themselves that the loss doesn't matter, that these things aren't important. That's a damned shame. We need to develop better means of energy generation, high-speed transport, and space access if we are to have a livable planet with 10 billion people on it.
Note, I'm not disputing that there have been tremendous advances in other areas (information technoogy, obviously). I'm just saying that it isn't uninterrupted progress everywhere you look.