The one major drawback to nuclear energy is the long term disposal and maintanance of the radioactive waste.
Right now, there are coal plants around the globe that are merrily spewing radioisotopes into the atmosphere; some coal has levels of uranium of 10ppm, and even higher levels of thorium, and just the amount of uranium the US has spat into the atmosphere since the 1930s could have, if fissioned instead, provided the entire present-day electrical demand of the entire United Kingdom for centuries. Seriously, I'm not joking. Since 1937, in the course of burning coal the US has dumped 145,000 tons of uranium into the atmosphere. That's 10,440 tons of U-235, which fissions to produce about 17.6 kilotons/kilogram. Fission all that, you get 193 petawatt-hours, which is the current electrical demand of the entire UK for 500 years.
That's real radioactivity, that causes real illness and kills real people. So why isn't burning coal prohibitively expensive? Why doesn't the 'disposal and maintanance of the radioactive waste' drive the cost up?
The reason is because the regulations for dealing with radioactive waste are a joke. They've got little to do with real risks, real costs, and a lot more to do with public fear and hysteria over anything that has the word 'nuclear' in it, which is why if you twist your knee playing football you go to get an MRI scan instead of an NMR scan. If a human being were considered under the regulations dicating the disposal of radioactive waste, then simply the naturally-occurring radioisotopes in the body would make cremation or burial in wooden coffins illegal. But nobody's bothered by that, either because they don't know that all organic matter is radioactive, or because they think that somehow K-40 in organic tissue is different from K-40 that's sitting in a used fuel rod.
Blaming public ignorance, fear, uncertainty, and doubt for the high cost of nuclear power does the best technology we have available to us if we want to maintain our standard of living *and* clean up the planet a great disservice. Right now, every kilowatt-hour we get from burning coal dumps 2.3 pounds of CO2 into the atmosphere, so for a country like the UK which gets 74% of its power from burning coal, that's 614 billion pounds of CO2, every year.
There is no way in hell the real costs of handling nuclear waste even come close to the costs of all that pollution. No. Fucking. Way. In contrast, a typical, 1000-MW nuclear plant produces something like 20 tons of high-level waste per year; that's under 50 *pounds* of waste per megawatt of plant capacity, and since it's so dense, volumetrically that's practically negligible.
Much of the high cost of nuclear waste is directly due to stupid-assed government regulations that are based upon the fact that PWRs in this country are a byproduct of nuclear weapons programs. They *prohibit* reactor designs that include fuel recycling, using additional reactor stages to burn the 'waste' produced by earlier stages. Don't want to deal with the waste for 10,000 years? Fine. Dump it into a seafloor subduction zone, by the time it sees the light of day again it won't be any more radioactive than any other molten material that spews forth from the Earth on a daily basis.
Considering that much of high level radioactive waste has a half-life of 12,000 years
If it has a half-life that long, it's not high-level.
While nuclear power is cheap if you measure it in cost per KWH, it's only cheaper if you ignore the health costs.
What health costs? Nuclear power in the US has killed how many people? I think 3, if you cound the SL-1 accident, which wasn't a civilian plant. Certainly under 100. In contrast, something like 50-100,000 people die each year in the US alone because of air pollution. A lot of that's due to indoor pollution, but much of it's because of all the crud fossil fuel plants spit into the air.
Take all the nuclear waste, and dump it right to the bottom of an abyssal trench in plain steel drums, and the health costs would be vastly lower than those caused by the burning of fossil fuels. Per megawatt-hour, nuclear plants release *much* less radioactive material into the atmosphere than coal plants do; those spit out plenty of thorium and uranium, and that's not even mentioning the heavy metals and particulates that cause real damage and kill real people.
The fear about nuclear waste is nothing more than FUD. Volumetrically, we're talking about incredibly tiny quantities of waste. It's really a non-issue, except for the political hysteria.
Solar/wind/hydroelectric? Not practical for generating all the electricity we use right now, let alone all we'd need to use if we want a hydrogen economy. If you want to cut out burning coal and gas, nuclear is the only option.
If you have a way to generate the hydrogen that's cheap enough, you don't care about that inefficiency. Heck, the efficiency of a gasoline-powered IC car is about 12%, but people don't care, are are only beginning to care about the inefficiency now that gas is as expensive as it is.
To make hydrogen meaningful, you need a way to generate large quantities of it cheaply, which basically means using nuclear power as your primary means of generating electricity. I mean, sure, you could get it by cracking hydrocarbons, but since your goal is to get away from needing hydrocarbons, that doesn't help much. And if you use nuclear power as your primary means of generating electricity, you can make enough hydrogen that 12% efficiency from an IC engine is just fine.
Is hydrogen energy dense enough to be a good fuel for a comercial airliner?
Oh, *hell* yes. For weight-limited applications like air-travel, hydrogen walks all *over* dead dinosaurs. It's volumetric density is piss-poor, which is why you'd need your car's fuel system pressurized to about 5,000psi if you want to get as far on 16-gallon tank of hydrogen as you do on a 16-gallon tank of gasoline, but if you're talking massic energy density? Hooboy.
H2: 140 MJ/kg Diesel/gasoline/avgas: ~46.8 MJ/kg
Granted, at STP those H2 tanks would definitely be prohibitively large, but big honking airplanes already deal with highly-pressurized systems, for moving flight control surfaces around, so carting the stuff around at a few thousand psi really isn't a big deal.
Do it underground, in a big cavern. The heat from the reaction radiates outward into the rocks, you use the hot rocks to generate steam, and just keep dropping fusion pellets into the chamber and igniting them at the center.
Really, that's about the *smallest* problem in turning ICF into a power-generation scheme, which is why it's never going to be used as a power-generation scheme.
The issue isn't that you turn the vessel radioactive by neutron bombardment. You do, but that's not the reason you need to replace it. It's because the neutron collissions eventually knock every single atomic nucleus in the vessel around.
It produces a boat load a neutrons
No, it doesn't. Not compared to what a functional fusion reactor will generate. We really don't even have the means to generate enough neutrons to *test the materials* for the construction of real fusion plants. Fission plants don't come *close*; fission of U-235 releases something like 2% of the reaction energy in the form of neutrons, for D-T fusion you're looking at 80%, and the neutron flux in a D-T reactor will be roughly two orders of magnitude more than from a PWR, so no, the reactor in the bottom of the chem basement of UC Irvine doesn't even come close to what we're talking about.
I think you're making this problem out ot be far worse that it is.
And I think you're ignorant of how significant the problem is.
Over a 30-year life, a fusion reactor vessel will experience 300 to 500 displacements per atom. Austenitic steels start to swell and distort after only about 30 dpa, and even low-activation steels or silicon carbides can only get up to about 150 dpa without significant degradation. The materials test facility counterpart to ITER, IFMIF, is still only in its design stages, so this isn't a problem that will be solved anytime soon, even if ITER figures out all the other stuff overnight.
Well, for starters, launching a payload to intersect the sun takes a *lot* more delta-v than just launching it on a solar escape trajectory.
Then there are the hazard issues of launching fissile waste on big rockets, which do have a tendency to blow up. Yes, yes, RTGs are very safe, but they're designed that way from the ground up, and designing that sort of safety into a *waste* container sounds like a really expensive, and dumb, idea.
Third, waste is potentially useful. The entire PWR reactor was designed around a military fuel chain. Other, better reactor designs could be multistage, each stage burning the 'waste' from a previous one.
Fourth, the waste amounts we're talking about are volumetrically tiny, because the materials are so dense. The hullabaloo over proper disposal is really just a bunch of FUD. You could switch over entirely to nuclear power, take every bit of high-level waste you generate, put it into unlined drums, and dump it right to the bottom of a deep-sea trench, and you'd do vastly less environmental damage than we're doing right now by burning fossil fuels. Hell, dump it in big masses to the seafloor, *let it go critical* and melt its way down into the mantle, and nobody will ever notice it. It's a non-issue, except for the FUD.
Actually, the bremsstrahlung is how you get the energy out of the plasma, heating the wall. Only a fraction of the energy of the fusion products is used to keep the plasma heated, the rest has to get out of the confinement region -- to make steam.
Right, and if you have the energy coming out as 4.7 MeV neutrons, you capture them in a material with a high neutron-capture cross-section, like lithium, and in the process of doing that you also breed tritium which you use to refuel the reactor.
If, on the other hand, it comes out as a charged particle like a proton, it interacts with the electrons flying around in the plasma, and loses all its energy before you can extract it.
Read the paper I linked to. It explains why such losses are death for pretty much any aneutronic fusion scheme.
They don't even approach being power-generation schemes.
Generation fusion reactions is easy. Generating them in such a way that you get more energy out of them than you put in is very, very difficult. Farnsworth fusors don't come close. With them, the killer is power density. Charge accumulation prevents a power density greater than a few watts per cubic meter.
Seriously, this paper needs to be read by everyone involved in talking about fusion power. It's pretty much the death knell for any scheme that isn't magnetic confinement of D-T fusion.
Sure, if you ignore the fact that it's about 16 times harder to even initiate the reaction, *and* the fact that since most of the energy comes off the reaction as a 15 MeV proton, the Bremsstrahlung losses absolutely kill you.
The more you look into magnetic confinement fusion, the more it seems that there's almost some sort of cosmic conspiracy to prevent us from using it as a power generation scheme. Go with neutronic fusion to avoid losing all your produced power to collisions with electrons in the plasma, and you run up against materials limitations. Try to avoid that problem, and you suddenly have a reaction that is *grotesquely* less efficient, to the point where it's probably not *possible* to even *break even*. To reduce those losses, you need to operate at even *higher* temperatures that it takes just to initiate the reaction, but when you do that, you lower your power density relative to D-T by a similar proportion and make containment that much harder.
Seriously, we do not have the time to keep generating power by fossil fuels until we get fusion to work, because that might never happen, the problems are that significant. Even that big new testbed reactor that's going up in France won't really get us close, because it's not dealing with the materials issue; over the lifetime of a fusion reactor, *every single atom* in the containment vessel will be struck by neutrons hundreds or even thousands of times, and we don't know how to build materials that can withstand that sort of irradiation without swelling, distorting, cracking, and a variety of other things you don't want to see in a nuclear containment vessel.
On the other hand, we know how to make *fission* work, and we should switch to that *now*. By the time we start making a dent in the fissionable fuels available to us, we should know how to build large-scale structures in orbit, and can just switch to solar collection satellites. I sincerely doubt if we'll ever even use fusion for power generation; by the time we ever figure out how to do it, it's likely there will be superior options available to us.
New Line was going to stop existing as a movie studio, until they turned some books into films. They were written by a guy named Tolkien, and the movies received wide critical acclaim and grossed something like 3 billion dollars worldwide.
So that's probably not particular good advice.
In other words, what's wrong with turning books into films? Sure, the oft-heard lament is "The book was better," and that may be true, but some damned fine movies get made from books, or comic books, or plays. Heck, just from the IMDB Top 250:
1. The Godfather - book by Mario Puzo 2. Shawshank Redemption - novella by Steven King 3. Return of the King - duh 7. Casablanca - play by Burnett and Alison 12. FOTR 13. Cuckoo's Next - book by Kesey 14. TTT 28. Lawrence of Arabia - memoirs by Lawrence of Arabia
I'm not going to go on, because there's a lot more, but c'mon. I'm not even listing things like Spider-Man and the X-men movies, because despite box office receipts it could certainly be argued that those aren't great movies.
But The Wizard of Oz? Mutiny on the Bounty? Blade Runner? War of the Worlds? Rosemary's Baby? Doctor Zhivago? Deliverance? The Maltese Falcon? Fight Club? Gone With the Wind? Full Metal Jacket?
I must admit to being very curious as to why you don't want them to make more films as good as those.
$19 for 2 tickets is a helluva difference from $30/person.
Yes, the drinks and food are ridiculously overpriced, because that's where theaters make their money. That doesn't mean you have to buy them, so it's silly to include them in the cost of seeing a film. What, you can't go 2 hours without stuffing your face? Why would you spend 15 bucks on a cup of Coke and a tub of popcorn? I mean, if that's what you want, a 2-liter bottle of cola and a 3-pack of microwave popcorn runs probably less than 5 bucks at a supermarket.
Going to see a movie costs you $9.50 a ticket. It's not like you *have* to spend more money than the ticket costs.
Well, to help someone achieve a command of the language, the first step is helping them enjoy writing
That comes later. The first step is teaching them to think coherently. Nine times out of ten, when you see someone's writing and it reads like it was written by a retarded teenage monkey on crack, that sloppy and incoherent writing reflects sloppy and incoherent thought.
yeah, i know; if you think my writing is bad now you should have seen my writing in high school!)
My *handwriting* hasn't developed past the 7th grade, because that's what I acquired access to a computer and began typing everything I could instead of writing it out longhand. There's something to be said for learning to write, as opposed to type, for much the same reason why you shouldn't give kids calculators as soon as you want to start teaching them math.
Indeed. I think ultimately we're arguing for the same thing - you're arguing teach the mental habits without using any specific application of them, I'm arguing the only way to teach that mental process is using a specific application that rewards it.
It sounds like we are. But to clarify, I think it's pretty clear that the entire school system is broken, at that the kids who come out of it well-prepared for further endeavours do so in spite of the system, not because of it. Right now you've got ignorant and incompetent teachers teaching subjects they're not familiar with, in a pedagogical manner that's infinitely more concerned with rote memorization than it is with thinking skills and the toolbox that is rational thought.
Before you can teach math, or science, or computer programming and database architecture, you've got to fix that underlying problem, or all you're going to be doing is turning out shitty computer programmers instead of functional illiterates.
However, the mental skills needed to do google searches well are different from those needed to use a library card catalog.
No, they're not. The particulars of the tool differ, but the underlying mental skills remains the same. If you don't know how to categorize or evaluate information, you're not going to be able to use *any* search tool effectively.
You can't just teach students to use research tools in general.
Yes, you damned well can. Or, what, you want them to have a separate class in how to use Yahoo, or another one for Ask Jeeves? And then there's the phone book, gotta teach 'em how to use phone books...
Apart from, y'know, using computers? Learning about modern technology? How about becoming familiar with programming, testing and debugging? Using the internet as a research tool?
Using the internet as a research tool?
Why not just teach them how to use research tools in general? That way, whether they find themselves in front of a Google prompt *or* a library card catalog, they'll know how to go about finding the information they seek.
I've seen people try and fail to find what they're looking for on Google, because they don't know how information is logically categorized and classified and evaluated. If you can't teach them *that*, you can't teach them to use the internet as a research tool.
Programming, testing, debugging? That's fine for people who are going into CS, but for most people that's going to be like teaching everyone how to rebuild an upper engine block. Yes, there's *nothing wrong* with knowing that stuff, and yes, it's an area where disciplined and organized thought processes are important, but the goal of the school should be to teach those disciplined and organized thought processes; until it can do that, trying to teach a specific application like that is folly.
The skill of using a piece of word processing software is completely trivial compared to the skill of learning how to write and command the language.
If the scools were doing their job of turning out people with command of the language, then sure, okay, teach 'em how to use a word processor as well.
But if the schools aren't doing that job to satisfaction, and it's pretty clear that they're not, then buying the school a bunch of Winboxes and Office licenses is worse than useless. What good is a cadre of ignorant mouthbreathers who write in AIM-speak? Sure, they'll know how to use the tool, but they won't know what to *do* with it.
Teach someone proper thinking skills, put him down in front of a computer, and he'll learn how to use Office on his own. Teach him how to use a computer without teaching him how to think, and he's going to be useless for anything other than trained-monkey work.
Like the saying goes, "If you can't do something, you can't do it with a computer."
If we had schools capable of turning out well-educated young adults with a firm grounding in the fundamentals of rational thought and at least a working knowledge of math, language, history, and science, well, the absence of computers in the classroom and whatnot wouldn't be significant.
And if all you have are schools turning out masses of people so ignorant that they actually think "Left Behind" is a good series of books, the presence of computers in the classroom isn't going to matter one good goddamn.
No, they're not. They're there to raise money. In fact, every supposedly "criminal" activity that is punished by a fine, as opposed to actual jail time, is a crime solely because punishing people for it serves to fill the coffers of the state.
In the case of speed limits, traffic engineers have known for quite a while that the safest speed limit for a given road is the 85-percentile speed - the speed that 85% of the traffic travels on that road. It's not speed that kills, it's speed differential, and having slow drivers on fast roads is just as dangerous, if not more, than having fast drivers on slow roads. Setting speed limits to arbitrarily low values will result in a small percentage of drivers obeying them, and those drivers will present a significant hazard to people traveling at reasonable speeds for that road.
The fact is that raising or lowering speed limits has very little to do with how fast traffic moves. Here, look:
# Speed limits were posted, on average, between 5 and 16 mi/h (8 and 26 km/h) below the 85th percentile speed.
# Lowering speed limits by 5, 10, 15, or 20 mi/h (8, 16, 24, or 26 km/h) at the study sites had a minor effect on vehicle speeds. Posting lower speed limits does not decrease motorist's speeds.
# Raising speed limits by 5, 10, or 15 mi/h (8, 16, or 25 km/h) at the rural and urban sites had a minor effect on vehicle speeds. In other words, an increase in the posted speed limit did not create a corresponding increase in vehicle speeds.
# The average change in any of the percentile speeds at the experimental sites was less than 1.5 mi/h (2.4 m/h), regardless of whether the speed limit was raised or lowered.
# Where speed limits were lowered, an examination of speed distribution indicated the slowest drivers (1st percentile) increased their speed approximately 1 mi/h (1/6 km/h). There were no changes on the high-speed drivers (99th percentile)
# At sites where speed limits were raised, there was an increase of less than 1.5 mi/h (2.4 km/h) for drivers traveling at and below the 75th percentile speed. When the posted limits were raised by 10 and 15 mi/h (16 and 24 km/h), there was a small decrease in the 99th percentile speed.
# Raising speed limits in the region of the 85th percentile speed has an extremely beneficial effect on drivers complying with the posted speed limits.
# Lowering speed limits in the 33rd percentile speed (the average percentile that speed were posted in this study) provides a noncompliance rate of approximately 67 percent.
# After speed limits were altered at the experimental sites, less than one-half of the drivers complied with the new posed limits.
# Only minor changes in vehicles following as headways less than 2s were found at the experimental sites.
# Accidents at the 58 experimental sites where speed limits were lowered increased by 5.4 percent. The level of confidence of this estimate is 44 percent. The 95 percent confidence limits for this estimate ranges from a reduction in accidents of 11 percent to an increase of 26 percent.
# Accidents at the 41 experimental sites where speed limits were raised decreased by 6.7 percent. The level of confidence of this estimate in 59 percent. The 95 percent confidence limits for this estimate ranges from a reduction in accidents of 21 percent to an increase of 10 percent.
# Lowering speed limits more than 5 mi/h (8 km/h) below the 85th percentile speed of traffic did not reduce accidents.
The time to worry about traffic safety is when you're designing and building the road, not when you feel like monkeying around with speed limits. If you see a speed limit set lower than the 85% percentile speed, it's set that way so that the state can make money, not to make anyone safer.
Every country has the sovereign right to make its own laws.
Wrong. That is an outdated notion, stemming from the Peace of Westphalia, the notion that the fundamental political unit is the State.
Modern political theory holds that the fundamental political unit is the individual. You may be familiar with a popular espousal of this political theory:
We hold these truths to be self-evident, that all men are created equal, that they are endowed by their Creator with certain unalienable Rights, that among these are Life, Liberty and the pursuit of Happiness. --That to secure these rights, Governments are instituted among Men, deriving their just powers from the consent of the governed, --That whenever any Form of Government becomes destructive of these ends, it is the Right of the People to alter or to abolish it, and to institute new Government, laying its foundation on such principles and organizing its powers in such form, as to them shall seem most likely to effect their Safety and Happiness.
Governments derive their legitimacy from the consent of the governed. They, States, do not have rights, they have powers, and when they exercise those powers without the consent of those governed, then those governments are *not* legitimate ones, they're just a bunch of thugs with guns and the will to use them.
Self-interest isn't the same thing as acting like an overblown bully, which the poster to whom I originally responded claimed was all the US ever was and is.
It's in my self-interest to get up in the morning, go to work, and collect a paycheck. I do not work for my employer out of altruism. But that's not at all the same thing as mugging people in alleys.
Yes, self-interest was plenty of reason to intervene. And yet our intervention was not the action of a bully.
I brought you an example when there would have been an easy situation to solve and the USA didn't.
So we fucked up. It happens, human decision-making is flawed, and hingsight is 20/20.
This occasion proves that the USA didn't or still doesn't care about human life more than the USSR did
No, it doesn't. All it proves is that we're capable of error, like that's some fucking revelation.
The assertion that the US is, and always has been, nothing but a bully can be disproved by a single counterexample, which I have provided. Examples of past fuckups on the part of the US are insufficient to confirm that assertion.
you are just protecting your own interests, so there is no moral high horse for you to sit on.
Every nation acts to protect its own interests. The moral difference arises from the differences in those interests. The Soviet Union overran Poland in WWII, and went on to rule it oppressively for another 40 years. America overran France and Italy and Germany and Japan in WWII, and went on to allow them to rule themselves as democratic states.
Both America and the Soviet Union were acting what they perceived to be their best interests, but if you're going to suggest that both actions were morally equivalent, I'm going to laugh at you and call you an asshat.
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The one major drawback to nuclear energy is the long term disposal and maintanance of the radioactive waste.
Right now, there are coal plants around the globe that are merrily spewing radioisotopes into the atmosphere; some coal has levels of uranium of 10ppm, and even higher levels of thorium, and just the amount of uranium the US has spat into the atmosphere since the 1930s could have, if fissioned instead, provided the entire present-day electrical demand of the entire United Kingdom for centuries. Seriously, I'm not joking. Since 1937, in the course of burning coal the US has dumped 145,000 tons of uranium into the atmosphere. That's 10,440 tons of U-235, which fissions to produce about 17.6 kilotons/kilogram. Fission all that, you get 193 petawatt-hours, which is the current electrical demand of the entire UK for 500 years.
That's real radioactivity, that causes real illness and kills real people. So why isn't burning coal prohibitively expensive? Why doesn't the 'disposal and maintanance of the radioactive waste' drive the cost up?
The reason is because the regulations for dealing with radioactive waste are a joke. They've got little to do with real risks, real costs, and a lot more to do with public fear and hysteria over anything that has the word 'nuclear' in it, which is why if you twist your knee playing football you go to get an MRI scan instead of an NMR scan. If a human being were considered under the regulations dicating the disposal of radioactive waste, then simply the naturally-occurring radioisotopes in the body would make cremation or burial in wooden coffins illegal. But nobody's bothered by that, either because they don't know that all organic matter is radioactive, or because they think that somehow K-40 in organic tissue is different from K-40 that's sitting in a used fuel rod.
Blaming public ignorance, fear, uncertainty, and doubt for the high cost of nuclear power does the best technology we have available to us if we want to maintain our standard of living *and* clean up the planet a great disservice. Right now, every kilowatt-hour we get from burning coal dumps 2.3 pounds of CO2 into the atmosphere, so for a country like the UK which gets 74% of its power from burning coal, that's 614 billion pounds of CO2, every year.
There is no way in hell the real costs of handling nuclear waste even come close to the costs of all that pollution. No. Fucking. Way. In contrast, a typical, 1000-MW nuclear plant produces something like 20 tons of high-level waste per year; that's under 50 *pounds* of waste per megawatt of plant capacity, and since it's so dense, volumetrically that's practically negligible.
Much of the high cost of nuclear waste is directly due to stupid-assed government regulations that are based upon the fact that PWRs in this country are a byproduct of nuclear weapons programs. They *prohibit* reactor designs that include fuel recycling, using additional reactor stages to burn the 'waste' produced by earlier stages. Don't want to deal with the waste for 10,000 years? Fine. Dump it into a seafloor subduction zone, by the time it sees the light of day again it won't be any more radioactive than any other molten material that spews forth from the Earth on a daily basis.
Considering that much of high level radioactive waste has a half-life of 12,000 years
If it has a half-life that long, it's not high-level.
Yep. It's amazing how a good idea can have its implementation prevented by sufficient FUD, isn't it?
While nuclear power is cheap if you measure it in cost per KWH, it's only cheaper if you ignore the health costs.
What health costs? Nuclear power in the US has killed how many people? I think 3, if you cound the SL-1 accident, which wasn't a civilian plant. Certainly under 100. In contrast, something like 50-100,000 people die each year in the US alone because of air pollution. A lot of that's due to indoor pollution, but much of it's because of all the crud fossil fuel plants spit into the air.
Take all the nuclear waste, and dump it right to the bottom of an abyssal trench in plain steel drums, and the health costs would be vastly lower than those caused by the burning of fossil fuels. Per megawatt-hour, nuclear plants release *much* less radioactive material into the atmosphere than coal plants do; those spit out plenty of thorium and uranium, and that's not even mentioning the heavy metals and particulates that cause real damage and kill real people.
The fear about nuclear waste is nothing more than FUD. Volumetrically, we're talking about incredibly tiny quantities of waste. It's really a non-issue, except for the political hysteria.
Solar/wind/hydroelectric? Not practical for generating all the electricity we use right now, let alone all we'd need to use if we want a hydrogen economy. If you want to cut out burning coal and gas, nuclear is the only option.
If you have a way to generate the hydrogen that's cheap enough, you don't care about that inefficiency. Heck, the efficiency of a gasoline-powered IC car is about 12%, but people don't care, are are only beginning to care about the inefficiency now that gas is as expensive as it is.
To make hydrogen meaningful, you need a way to generate large quantities of it cheaply, which basically means using nuclear power as your primary means of generating electricity. I mean, sure, you could get it by cracking hydrocarbons, but since your goal is to get away from needing hydrocarbons, that doesn't help much. And if you use nuclear power as your primary means of generating electricity, you can make enough hydrogen that 12% efficiency from an IC engine is just fine.
Is hydrogen energy dense enough to be a good fuel for a comercial airliner?
Oh, *hell* yes. For weight-limited applications like air-travel, hydrogen walks all *over* dead dinosaurs. It's volumetric density is piss-poor, which is why you'd need your car's fuel system pressurized to about 5,000psi if you want to get as far on 16-gallon tank of hydrogen as you do on a 16-gallon tank of gasoline, but if you're talking massic energy density? Hooboy.
H2: 140 MJ/kg
Diesel/gasoline/avgas: ~46.8 MJ/kg
Granted, at STP those H2 tanks would definitely be prohibitively large, but big honking airplanes already deal with highly-pressurized systems, for moving flight control surfaces around, so carting the stuff around at a few thousand psi really isn't a big deal.
Do it underground, in a big cavern. The heat from the reaction radiates outward into the rocks, you use the hot rocks to generate steam, and just keep dropping fusion pellets into the chamber and igniting them at the center.
Really, that's about the *smallest* problem in turning ICF into a power-generation scheme, which is why it's never going to be used as a power-generation scheme.
You are so wrong.
The issue isn't that you turn the vessel radioactive by neutron bombardment. You do, but that's not the reason you need to replace it. It's because the neutron collissions eventually knock every single atomic nucleus in the vessel around.
It produces a boat load a neutrons
No, it doesn't. Not compared to what a functional fusion reactor will generate. We really don't even have the means to generate enough neutrons to *test the materials* for the construction of real fusion plants. Fission plants don't come *close*; fission of U-235 releases something like 2% of the reaction energy in the form of neutrons, for D-T fusion you're looking at 80%, and the neutron flux in a D-T reactor will be roughly two orders of magnitude more than from a PWR, so no, the reactor in the bottom of the chem basement of UC Irvine doesn't even come close to what we're talking about.
I think you're making this problem out ot be far worse that it is.
And I think you're ignorant of how significant the problem is.
Over a 30-year life, a fusion reactor vessel will experience 300 to 500 displacements per atom. Austenitic steels start to swell and distort after only about 30 dpa, and even low-activation steels or silicon carbides can only get up to about 150 dpa without significant degradation. The materials test facility counterpart to ITER, IFMIF, is still only in its design stages, so this isn't a problem that will be solved anytime soon, even if ITER figures out all the other stuff overnight.
Well, for starters, launching a payload to intersect the sun takes a *lot* more delta-v than just launching it on a solar escape trajectory.
Then there are the hazard issues of launching fissile waste on big rockets, which do have a tendency to blow up. Yes, yes, RTGs are very safe, but they're designed that way from the ground up, and designing that sort of safety into a *waste* container sounds like a really expensive, and dumb, idea.
Third, waste is potentially useful. The entire PWR reactor was designed around a military fuel chain. Other, better reactor designs could be multistage, each stage burning the 'waste' from a previous one.
Fourth, the waste amounts we're talking about are volumetrically tiny, because the materials are so dense. The hullabaloo over proper disposal is really just a bunch of FUD. You could switch over entirely to nuclear power, take every bit of high-level waste you generate, put it into unlined drums, and dump it right to the bottom of a deep-sea trench, and you'd do vastly less environmental damage than we're doing right now by burning fossil fuels. Hell, dump it in big masses to the seafloor, *let it go critical* and melt its way down into the mantle, and nobody will ever notice it. It's a non-issue, except for the FUD.
Actually, the bremsstrahlung is how you get the energy out of the plasma, heating the wall. Only a fraction of the energy of the fusion products is used to keep the plasma heated, the rest has to get out of the confinement region -- to make steam.
Right, and if you have the energy coming out as 4.7 MeV neutrons, you capture them in a material with a high neutron-capture cross-section, like lithium, and in the process of doing that you also breed tritium which you use to refuel the reactor.
If, on the other hand, it comes out as a charged particle like a proton, it interacts with the electrons flying around in the plasma, and loses all its energy before you can extract it.
Read the paper I linked to. It explains why such losses are death for pretty much any aneutronic fusion scheme.
What about the Farnsworth EIC devices?
They don't even approach being power-generation schemes.
Generation fusion reactions is easy. Generating them in such a way that you get more energy out of them than you put in is very, very difficult. Farnsworth fusors don't come close. With them, the killer is power density. Charge accumulation prevents a power density greater than a few watts per cubic meter.
Seriously, this paper needs to be read by everyone involved in talking about fusion power. It's pretty much the death knell for any scheme that isn't magnetic confinement of D-T fusion.
It doesn't, but IC fusion doesn't even approach being a power-generation scheme.
Much better?
Sure, if you ignore the fact that it's about 16 times harder to even initiate the reaction, *and* the fact that since most of the energy comes off the reaction as a 15 MeV proton, the Bremsstrahlung losses absolutely kill you.
The more you look into magnetic confinement fusion, the more it seems that there's almost some sort of cosmic conspiracy to prevent us from using it as a power generation scheme. Go with neutronic fusion to avoid losing all your produced power to collisions with electrons in the plasma, and you run up against materials limitations. Try to avoid that problem, and you suddenly have a reaction that is *grotesquely* less efficient, to the point where it's probably not *possible* to even *break even*. To reduce those losses, you need to operate at even *higher* temperatures that it takes just to initiate the reaction, but when you do that, you lower your power density relative to D-T by a similar proportion and make containment that much harder.
Seriously, we do not have the time to keep generating power by fossil fuels until we get fusion to work, because that might never happen, the problems are that significant. Even that big new testbed reactor that's going up in France won't really get us close, because it's not dealing with the materials issue; over the lifetime of a fusion reactor, *every single atom* in the containment vessel will be struck by neutrons hundreds or even thousands of times, and we don't know how to build materials that can withstand that sort of irradiation without swelling, distorting, cracking, and a variety of other things you don't want to see in a nuclear containment vessel.
On the other hand, we know how to make *fission* work, and we should switch to that *now*. By the time we start making a dent in the fissionable fuels available to us, we should know how to build large-scale structures in orbit, and can just switch to solar collection satellites. I sincerely doubt if we'll ever even use fusion for power generation; by the time we ever figure out how to do it, it's likely there will be superior options available to us.
Stop turning books/comics into films.
New Line was going to stop existing as a movie studio, until they turned some books into films. They were written by a guy named Tolkien, and the movies received wide critical acclaim and grossed something like 3 billion dollars worldwide.
So that's probably not particular good advice.
In other words, what's wrong with turning books into films? Sure, the oft-heard lament is "The book was better," and that may be true, but some damned fine movies get made from books, or comic books, or plays. Heck, just from the IMDB Top 250:
1. The Godfather - book by Mario Puzo
2. Shawshank Redemption - novella by Steven King
3. Return of the King - duh
7. Casablanca - play by Burnett and Alison
12. FOTR
13. Cuckoo's Next - book by Kesey
14. TTT
28. Lawrence of Arabia - memoirs by Lawrence of Arabia
I'm not going to go on, because there's a lot more, but c'mon. I'm not even listing things like Spider-Man and the X-men movies, because despite box office receipts it could certainly be argued that those aren't great movies.
But The Wizard of Oz? Mutiny on the Bounty? Blade Runner? War of the Worlds? Rosemary's Baby? Doctor Zhivago? Deliverance? The Maltese Falcon? Fight Club? Gone With the Wind? Full Metal Jacket?
I must admit to being very curious as to why you don't want them to make more films as good as those.
$19 for 2 tickets is a helluva difference from $30/person.
Yes, the drinks and food are ridiculously overpriced, because that's where theaters make their money. That doesn't mean you have to buy them, so it's silly to include them in the cost of seeing a film. What, you can't go 2 hours without stuffing your face? Why would you spend 15 bucks on a cup of Coke and a tub of popcorn? I mean, if that's what you want, a 2-liter bottle of cola and a 3-pack of microwave popcorn runs probably less than 5 bucks at a supermarket.
Going to see a movie costs you $9.50 a ticket. It's not like you *have* to spend more money than the ticket costs.
Well, to help someone achieve a command of the language, the first step is helping them enjoy writing
That comes later. The first step is teaching them to think coherently. Nine times out of ten, when you see someone's writing and it reads like it was written by a retarded teenage monkey on crack, that sloppy and incoherent writing reflects sloppy and incoherent thought.
yeah, i know; if you think my writing is bad now you should have seen my writing in high school!)
My *handwriting* hasn't developed past the 7th grade, because that's what I acquired access to a computer and began typing everything I could instead of writing it out longhand. There's something to be said for learning to write, as opposed to type, for much the same reason why you shouldn't give kids calculators as soon as you want to start teaching them math.
Indeed. I think ultimately we're arguing for the same thing - you're arguing teach the mental habits without using any specific application of them, I'm arguing the only way to teach that mental process is using a specific application that rewards it.
It sounds like we are. But to clarify, I think it's pretty clear that the entire school system is broken, at that the kids who come out of it well-prepared for further endeavours do so in spite of the system, not because of it. Right now you've got ignorant and incompetent teachers teaching subjects they're not familiar with, in a pedagogical manner that's infinitely more concerned with rote memorization than it is with thinking skills and the toolbox that is rational thought.
Before you can teach math, or science, or computer programming and database architecture, you've got to fix that underlying problem, or all you're going to be doing is turning out shitty computer programmers instead of functional illiterates.
However, the mental skills needed to do google searches well are different from those needed to use a library card catalog.
No, they're not. The particulars of the tool differ, but the underlying mental skills remains the same. If you don't know how to categorize or evaluate information, you're not going to be able to use *any* search tool effectively.
You can't just teach students to use research tools in general.
Yes, you damned well can. Or, what, you want them to have a separate class in how to use Yahoo, or another one for Ask Jeeves? And then there's the phone book, gotta teach 'em how to use phone books...
Apart from, y'know, using computers? Learning about modern technology? How about becoming familiar with programming, testing and debugging? Using the internet as a research tool?
Using the internet as a research tool?
Why not just teach them how to use research tools in general? That way, whether they find themselves in front of a Google prompt *or* a library card catalog, they'll know how to go about finding the information they seek.
I've seen people try and fail to find what they're looking for on Google, because they don't know how information is logically categorized and classified and evaluated. If you can't teach them *that*, you can't teach them to use the internet as a research tool.
Programming, testing, debugging? That's fine for people who are going into CS, but for most people that's going to be like teaching everyone how to rebuild an upper engine block. Yes, there's *nothing wrong* with knowing that stuff, and yes, it's an area where disciplined and organized thought processes are important, but the goal of the school should be to teach those disciplined and organized thought processes; until it can do that, trying to teach a specific application like that is folly.
The skill of using a piece of word processing software is completely trivial compared to the skill of learning how to write and command the language.
If the scools were doing their job of turning out people with command of the language, then sure, okay, teach 'em how to use a word processor as well.
But if the schools aren't doing that job to satisfaction, and it's pretty clear that they're not, then buying the school a bunch of Winboxes and Office licenses is worse than useless. What good is a cadre of ignorant mouthbreathers who write in AIM-speak? Sure, they'll know how to use the tool, but they won't know what to *do* with it.
Teach someone proper thinking skills, put him down in front of a computer, and he'll learn how to use Office on his own. Teach him how to use a computer without teaching him how to think, and he's going to be useless for anything other than trained-monkey work.
Like the saying goes, "If you can't do something, you can't do it with a computer."
If we had schools capable of turning out well-educated young adults with a firm grounding in the fundamentals of rational thought and at least a working knowledge of math, language, history, and science, well, the absence of computers in the classroom and whatnot wouldn't be significant.
And if all you have are schools turning out masses of people so ignorant that they actually think "Left Behind" is a good series of books, the presence of computers in the classroom isn't going to matter one good goddamn.
No, they're not. They're there to raise money. In fact, every supposedly "criminal" activity that is punished by a fine, as opposed to actual jail time, is a crime solely because punishing people for it serves to fill the coffers of the state.
In the case of speed limits, traffic engineers have known for quite a while that the safest speed limit for a given road is the 85-percentile speed - the speed that 85% of the traffic travels on that road. It's not speed that kills, it's speed differential, and having slow drivers on fast roads is just as dangerous, if not more, than having fast drivers on slow roads. Setting speed limits to arbitrarily low values will result in a small percentage of drivers obeying them, and those drivers will present a significant hazard to people traveling at reasonable speeds for that road.
The fact is that raising or lowering speed limits has very little to do with how fast traffic moves. Here, look:
The time to worry about traffic safety is when you're designing and building the road, not when you feel like monkeying around with speed limits. If you see a speed limit set lower than the 85% percentile speed, it's set that way so that the state can make money, not to make anyone safer.
Wrong. That is an outdated notion, stemming from the Peace of Westphalia, the notion that the fundamental political unit is the State.
Modern political theory holds that the fundamental political unit is the individual. You may be familiar with a popular espousal of this political theory:
Governments derive their legitimacy from the consent of the governed. They, States, do not have rights, they have powers, and when they exercise those powers without the consent of those governed, then those governments are *not* legitimate ones, they're just a bunch of thugs with guns and the will to use them.
Just like China.
No, dammit.
Self-interest isn't the same thing as acting like an overblown bully, which the poster to whom I originally responded claimed was all the US ever was and is.
It's in my self-interest to get up in the morning, go to work, and collect a paycheck. I do not work for my employer out of altruism. But that's not at all the same thing as mugging people in alleys.
Yes, self-interest was plenty of reason to intervene. And yet our intervention was not the action of a bully.
Words mean things.
I brought you an example when there would have been an easy situation to solve and the USA didn't.
So we fucked up. It happens, human decision-making is flawed, and hingsight is 20/20.
This occasion proves that the USA didn't or still doesn't care about human life more than the USSR did
No, it doesn't. All it proves is that we're capable of error, like that's some fucking revelation.
The assertion that the US is, and always has been, nothing but a bully can be disproved by a single counterexample, which I have provided. Examples of past fuckups on the part of the US are insufficient to confirm that assertion.
you are just protecting your own interests, so there is no moral high horse for you to sit on.
Every nation acts to protect its own interests. The moral difference arises from the differences in those interests. The Soviet Union overran Poland in WWII, and went on to rule it oppressively for another 40 years. America overran France and Italy and Germany and Japan in WWII, and went on to allow them to rule themselves as democratic states.
Both America and the Soviet Union were acting what they perceived to be their best interests, but if you're going to suggest that both actions were morally equivalent, I'm going to laugh at you and call you an asshat.
You mentioning Hungary is quite bad, because it was the USA who messed it up for the 10 million Hungarians at that time.
Yah, 'cause the USA was the nation that invaded it and butchered thousands of people.
Oh, wait, it wasn't.