... like when some aide lined out the entire Space Environment Center from NOAA's budget a few years ago -- after all, space is outside NOAA's bailiwick, so what are those goons doing? Turns out they're only ensuring the ongoing safety of the electrical grid and all of our comsats, phone systems, and aviation network...... or like when, in 1998, I and a host of colleages traveled to the island of Guadeloupe to study a solar eclipse, and none of our colleagues from the Naval Research Laboratory had a place to stay. Following DoD regulations, the NRL travel office had moved them from the recommended hotel to a much cheaper one just barely within the required search radius of 15 miles -- but that happened to be on a different island...
Unfortunately, the vast majority of laws and regulations are composed in a hurry by college interns or harried public servants.
This is a great statistical argument. It reminds me of the study I saw a few years ago about the link between sodium and high blood pressure -- essentially, most of the population-wide correlation between blood pressure and sodium intake comes from a small segment of the population that have weak kidneys. In the part of the population that has normal kidneys, salt intake (even at the insane levels that most North Americans ingest) isn't correlated to blood pressure.
High percentage yield (fissioning a large percentage of the nuclear fuel in your device) is somewhat difficult. High percentage yield with a tiny device is extremely difficult, as it involves many technical tricks (like hyper-compression of the plutonium metal) to reduce the amount of mass needed for criticality. It is much more plausible that NK went for a larger explosion but failed to assemble it properly.
The name of the game with fission bombs is "fast assembly". The idea is to make as many fissions as possible before the bomb, er, disassembles itself. To do that you have to be as supercritical as possible before the first fission of the chain reaction happens. With plutonium there is a high incidence of spontaneous fission, so there are always neutrons around and the reaction can get started before the bomb is supercritical enough. That means the reaction rate doesn't grow as quickly as it should, and less energy gets released before the bomb blows up. The result is that fewer fissions happen during (and in the instant before) the explosion, so you don't use as much of the nuclear fuel as you intended.
My point: with the technology that is probably available to NK, any nuclear explosion (large or small) would probably use about the same amount of plutonium -- simply use it more or less efficiently.
Nope, since it is direction sensitive. There is a very neat (and somewhat old) "neutrino photograph" of the Sun that they made, by keeping track of the direction Earth was pointed relative to the Sun. You can see the galaxy and nearby nuclear reactors as a kind of broad smudge in the background.
The point is that a nuclear bomb is thousands of times more explosive by weight than a conventional bomb, so a nuclear bomb that weighs a few tons can explode with the equivalent weight of thousands of tons of conventional explosive.
The debate is whether the NK regime tried (and failed) to properly detonate a plutonium device, or tried (and perhaps succeeded) to convince the world that they have nuclear weapons, simply by piling up a lot of conventional explosives and setting them off all at once.
It's not so hard to pile up ten thousand tons of conventional explosive, and as discussed in the previous thread on the test itself there is some value in convincing your neighbors that you have nuclear weapons regardless of whether you actually have them.
The revised seismic figures were (if I recall right) something like 0.5 kT equivalent. The smallest easy-to-build bombs (those that have supercritical assemblies without hyper-compression of the metal) yield something like 10-30 kT, so this was either a fizzled nuke or a large pile of ANFO (or something like that).
In the last discussion I made a big deal about the Kamioka observatory and how they "should" have been able to see neutrinos from the blast -- but with an 0.5kT blast the number of neutrino interactions is only 1 or 2, so they can't be expected to distinguish a large chemical explosion from a very small fizzled nuclear explosion.
... with internal combustion engines so small and easy to implement, they're showing up in personal vehicles and even handheld devices like weed-whackers. There's no reason to build all that infrastructure of central powerplants any more -- anyone who wants electricity can just run a small motor to generate it locally.
Though making a low-yield device with lots of plutonium is about as hard as making a small fortune by starting with a large one...:-)
If I had to place a bet, I'd bet that they tried for 10-15kT and got much less. The name of the game in fission bombs is fast assembly -- you want to get the reactor core assembled and way, way supercritical before a chain reaction has a chance to start. With uranium, that's easy since its spontaneous neutron emission rate is so low -- but wherever you have a chunk of plutonium you'll find many free neutrons bouncing around, so the assembly has to be much faster. I believe that's a large part of the reason that the first U.S. plutonium bomb used expensive, tricky implosion rather than simple, straightforward gun-type assembly like the uranium bomb did.
Hmmm... Super-K has 50,000 tonnes of water, so the total Super-K interaction cross section is something like:
5e4 tonnes * 1e6 g/tonne * 6.022e23 amu/g * 2 protons / 18g * 1e-44 m^2 / proton = 3e-11 m^2
So with a few x 10^13 particles intersecting Super-K one would expect something like a few x 30 events. Large enough to see, if the quantum efficiency of the detection isn't too low..
Well, from the other threads it was probably more like 2-3 kT than like 30 kT...
but, being underground, it's not so bad even with a larger (fully functioning?) device. One nice thing about underground nuclear testing (compared to air-testing) is that the device tends to fuse the surrounding rock into a hard, insoluble glass that immobilizes most of the fission products -- so, in principle, there's not much contamination of stuff above ground.
Sorry to say it, but your units aren't right. I have attempted to reverse-engineer your mistake.
300 billion antineutrinos per fission is just wrong, as are 3e11 antineutrinos per steradian. I think you meant 3e11 antineutrinos per square meter at 1Mm distance, which is right in line with what I calculated. (I assumed twice as many neutrinos per fission as you did, and used the published size of Kamiokande to estimate its cross section at 200 square meters -- which accounts for the factor-of-400 difference between our numbers.)
Not so unlikely, perhaps -- the greatest value in nukes is deterrence, ie in everyone else knowing that you have them. Plutonium devices are harder to get right than are uranium devices (because of the spontaneous neutron emission rate of the plutonium, which keeps you from getting as supercritical as you'd like before the reaction heats up -- which in turn would make the bomb fizzle as it, er, disassembles itself before liberating as much energy as the owners would like).
It's not inconceivable that Kim Jong Il might find it worthwhile to burn that much conventional explosive in a bid for credibility, if his weapons program were failing: nearly all of the value of nuclear weapons is in convincing your neighbors that you have them.
I assumed 2 neutrinos per fission (about 100 MeV per neutrino) and 200 m^2 for the cross sectional area of Kamiokande (to find the number of steradians it subtends). It's sort of awkward to write it all out, but heres the whole proportionality thing with all the units, so you can check that they all cancel and the 4pi is in the right place...
Seismic results can be faked with conventional explosives -- 30,000 tons of TNT is expensive but can be amassed even by a small nation like North Korea.
However, the world's most sensitive neutrino detector (Kamiokande) is under 1,000 km away. If the North Koreans detonated a 10-30 kiloton device, several times 1013 neutrinos from it should have passed through Kamiokande. I don't know Kamiokande's exact quantum efficiency, but it should be able to detect a pulse like that. After all, it detected Supernova 1987-A...
"doesn't need a super system"... Oh, the irony...
on
A Mac Fan's Take On Vista
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· Score: 3, Insightful
...XP 1700...1 gig of ram, several 250 gig hard drives... I will be throwing in an XP 2600...
How zippy is your machine? An XP 1700 wita a gigabyte of RAM is capable of simulating regional weather patterns in real time, or of calculating about 10,000 lunar orbital injection trajectories per second, or of playing 100 competition chess games simultaneously, or of analysing and controlling traffic patterns in a mid-sized city core.
So, er, your 1700 *is* a super system. With that much horsepower at your disposal, you shouldn't have to wait more than 0.1 second to start up your favorite application. If you notice *any* lag before any dialog box comes up, you should be questioning why.
I haven't watched Roulette in a few years, but traditionally the bets are placed while the ball is rolling around the perimeter of the wheel. That eliminates the possibility that the croupier could manipulate or time his toss based on the bets people have made. So, yes, that is the whole point of TFA: a measure that was adopted to address a security concern with gambling (the timing of the betting) makes it possible to defeat the chance element another way (by using numerical simulation to predict where the ball will land, based on early observation of its path around the wheel).
The "game" aspect of roulette is to try to guess on which number (or segment of the wheel) the ball will land. The point of roulette is that it is exceedingly difficult to guess the number based on the initial few seconds in which the ball is rolling around the top. However, with modern computers it can be done in time to place a real bet.
It wasn't the bush administration who leaked her name. It was some disgruntled employee who didn't agree with bushes policy (talk about undermining)
Citation please? The mainstream media seem to think it was some combination of Rove and Scooter Libby, neither of whome was a disgruntled employee.
The second point is the buysh lied, They use this report as proof and it all seemed as if it gave the bush basher the credit they deeply needed.
I'm not so sure what you're getting at here -- but remember all those months of claiming that Saddam Hussein supported Al Qaeda, and was developing weapons of mass destruction to launch at us? Remember how the loyal opposition was vilified for calling bullshit? We know how the WMD search turned out, and we know that U.S. intelligence knew at the time how it would turn out. Now a U.S. Senate report points out that, in fact, there was no link at all between Hussein and Al Qaeda, and that the Bush administration knew it.
There was no reason at all to go into Iraq. Bush lied. Over 2,000 of our young men died, and you personally spend $40,000 (and counting) for that lie. Sorry to bring you the harsh news, dude.
If W had followed through on his promises of humility and gentle government, yes, I think he could have been a "uniter". But instead he showed a pattern of disregarding anything he didn't want to hear, and undid a great many things that took a great many years to achieve. He had a big chance to unite the country, shortly after 9/11 when we all pulled together anyway -- but used that opportunity instead to try to make our homeland a torturing, wiretapping police state.
As to your last point, yes, the Clinton debacle was ridiculous. However - and I realize you'll find this ridiculous - Clinton did lie, plain and simple.
Putting aside any lawyerly evasions, it's ludicrous to compare a lie about a blowjob with a lie used in the leadup to a wasteful and unjustified war, with all the suffering, death, and costs (both societal and financial) that it entails. So far, over 2,000 good men have died more or less in vain for the sake of a repeated lie (that there was a clear and present reason to invade Iraq, rather than finishing the job in Afghanistan).
...when you say "Iraq has WMD", and you genuinely believe it (especially since the collective intelligence communities of the Western world believed it, the UN "believed" it (but wasn't ready to commit to military action for a wide variety of reasons), and Saddam himself believed it), and then it later turns out to not be true, is that a "lie"?
Yes, and it's perhaps the most effective and insidious type of lie. Deliberately denying the evidence of one's own senses (in this case, one's own cabinet and intelligence wings) is self-deception. Wilfully doing so is lying. It's much easier to lie to others if you first convince yourself.
Is doing things you firmly believe are within your powers as president, but may be legally questionable, a "lie"?
Yes, if you have good reason to believe otherwise but choose not to heed those reasons.
I realize that it's easy for people to sit here and fill themselves with anti-administration news constantly, and develop a very deeply-seated picture that the current administration is the biggest crop of deceitful, corrupt, greedy liars ever to set foot into Washington.
When actions and rhetoric disagree so strongly, it is indeed hard to conclue otherwise. Rather than turn this into a lengthy rant, I'll follow one example: If the Iraqi conflict were genuinely as important to our safety as the neocons imply, we should have a draft and a mobilized military-industrial complex, as we did during WWII (which, recall, lasted just 3.5 years). The neocons know that would be political suicide, because Iraq just isn't that important -- so they tried to do the job half-assed, with the same result they had 35 years earlier in Viet Nam -- an unhappy population, a growing insurgency, and no exit strategy. They knew (or at least ha seen reports saying) that Iraq had nothing to do with Al-Qaeda, that they had no WMDs, and that they were no current threat, but they still pushed that rhetoric and spent over $40,000 of your money (and another $40k from every man, woman, and child in the nation) on a pig in a poke.
W ran on the platform of being a uniter who would work hard to bring everyone together. Am I the only person who remembers those campaign speeches? We appear to be about as divided as we've ever been, as a nation.
I've heard this meme (that "the Democrats also steal a lot of elections") a lot lately but I have not seen anyone substantiate it. I don't recall anyone getting up in arms about the process of the Clinton elections, though certainly there were people upset that he won.
Does anyone have anything other than innuendo on this talking point? It sounds a little too much like a Rove snowjob to me -- I hear the talking point a lot from different sources but never any deeply resourced, specific complaints such as RFK aired.
... influencing the outcome of the game (e.g. with a magnet) is cheating. There's nothing in the rules of Roulette that says "The gamblers shall not attempt to predict when and where the ball lands" -- or, at least, not the last time I checked. Roulette is simply flawed in an era when palm-sized computers are ubiquitous. Similarly, blackjack can be beaten by card-counting, but card-counting is not cheating, it's good memory.
Slashdot Mirror
... like when some aide lined out the entire Space Environment Center from NOAA's budget a few years ago -- after all, space is outside NOAA's bailiwick, so what are those goons doing? Turns out they're only ensuring the ongoing safety of the electrical grid and all of our comsats, phone systems, and aviation network... ... or like when, in 1998, I and a host of colleages traveled to the island of Guadeloupe to study a solar eclipse, and none of our colleagues from the Naval Research Laboratory had a place to stay. Following DoD regulations, the NRL travel office had moved them from the recommended hotel to a much cheaper one just barely within the required search radius of 15 miles -- but that happened to be on a different island...
Unfortunately, the vast majority of laws and regulations are composed in a hurry by college interns or harried public servants.
This is a great statistical argument. It reminds me of the study I saw a few years ago about the link between sodium and high blood pressure -- essentially, most of the population-wide correlation between blood pressure and sodium intake comes from a small segment of the population that have weak kidneys. In the part of the population that has normal kidneys, salt intake (even at the insane levels that most North Americans ingest) isn't correlated to blood pressure.
High percentage yield (fissioning a large percentage of the nuclear fuel in your device) is somewhat difficult. High percentage yield with a tiny device is extremely difficult, as it involves many technical tricks (like hyper-compression of the plutonium metal) to reduce the amount of mass needed for criticality. It is much more plausible that NK went for a larger explosion but failed to assemble it properly.
The name of the game with fission bombs is "fast assembly". The idea is to make as many fissions as possible before the bomb, er, disassembles itself. To do that you have to be as supercritical as possible before the first fission of the chain reaction happens. With plutonium there is a high incidence of spontaneous fission, so there are always neutrons around and the reaction can get started before the bomb is supercritical enough. That means the reaction rate doesn't grow as quickly as it should, and less energy gets released before the bomb blows up. The result is that fewer fissions happen during (and in the instant before) the explosion, so you don't use as much of the nuclear fuel as you intended.
My point: with the technology that is probably available to NK, any nuclear explosion (large or small) would probably use about the same amount of plutonium -- simply use it more or less efficiently.
Nope, since it is direction sensitive. There is a very neat (and somewhat old) "neutrino photograph" of the Sun that they made, by keeping track of the direction Earth was pointed relative to the Sun. You can see the galaxy and nearby nuclear reactors as a kind of broad smudge in the background.
The point is that a nuclear bomb is thousands of times more explosive by weight than a conventional bomb, so a nuclear bomb that weighs a few tons can explode with the equivalent weight of thousands of tons of conventional explosive.
The debate is whether the NK regime tried (and failed) to properly detonate a plutonium device, or tried (and perhaps succeeded) to convince the world that they have nuclear weapons, simply by piling up a lot of conventional explosives and setting them off all at once.
It's not so hard to pile up ten thousand tons of conventional explosive, and as discussed in the previous thread on the test itself there is some value in convincing your neighbors that you have nuclear weapons regardless of whether you actually have them.
The revised seismic figures were (if I recall right) something like 0.5 kT equivalent. The smallest easy-to-build bombs (those that have supercritical assemblies without hyper-compression of the metal) yield something like 10-30 kT, so this was either a fizzled nuke or a large pile of ANFO (or something like that).
In the last discussion I made a big deal about the Kamioka observatory and how they "should" have been able to see neutrinos from the blast -- but with an 0.5kT blast the number of neutrino interactions is only 1 or 2, so they can't be expected to distinguish a large chemical explosion from a very small fizzled nuclear explosion.
... with internal combustion engines so small and easy to implement, they're showing up in personal vehicles and even handheld devices like weed-whackers. There's no reason to build all that infrastructure of central powerplants any more -- anyone who wants electricity can just run a small motor to generate it locally.
Come on, get real folks.
Yah, agree.
:-)
Though making a low-yield device with lots of plutonium is about as hard as making a small fortune by starting with a large one...
If I had to place a bet, I'd bet that they tried for 10-15kT and got much less. The name of the game in fission bombs is fast assembly -- you want to get the reactor core assembled and way, way supercritical before a chain reaction has a chance to start. With uranium, that's easy since its spontaneous neutron emission rate is so low -- but wherever you have a chunk of plutonium you'll find many free neutrons bouncing around, so the assembly has to be much faster. I believe that's a large part of the reason that the first U.S. plutonium bomb used expensive, tricky implosion rather than simple, straightforward gun-type assembly like the uranium bomb did.
Hmmm... Super-K has 50,000 tonnes of water, so the total Super-K interaction cross section is something like:
5e4 tonnes * 1e6 g/tonne * 6.022e23 amu/g * 2 protons / 18g * 1e-44 m^2 / proton = 3e-11 m^2
So with a few x 10^13 particles intersecting Super-K one would expect something like a few x 30 events. Large enough to
see, if the quantum efficiency of the detection isn't too low..
Well, from the other threads it was probably more like 2-3 kT than like 30 kT...
but, being underground, it's not so bad even with a larger (fully functioning?) device. One nice thing about underground nuclear testing (compared to air-testing) is that the device tends to fuse the surrounding rock into a hard, insoluble glass that immobilizes most of the fission products -- so, in principle, there's not much contamination of stuff above ground.
Sorry to say it, but your units aren't right. I have attempted to reverse-engineer your mistake.
300 billion antineutrinos per fission is just wrong, as are 3e11 antineutrinos per steradian. I think you meant 3e11 antineutrinos per square meter at 1Mm distance, which is right in line with what I calculated. (I assumed twice as many neutrinos per fission as you did, and used the published size of Kamiokande to estimate its cross section at 200 square meters -- which accounts for the factor-of-400 difference between our numbers.)
Not so unlikely, perhaps -- the greatest value in nukes is deterrence, ie in everyone else knowing that you have them. Plutonium devices are harder to get right than are uranium devices (because of the spontaneous neutron emission rate of the plutonium, which keeps you from getting as supercritical as you'd like before the reaction heats up -- which in turn would make the bomb fizzle as it, er, disassembles itself before liberating as much energy as the owners would like).
It's not inconceivable that Kim Jong Il might find it worthwhile to burn that much conventional explosive in a bid for credibility, if his weapons program were failing: nearly all of the value of nuclear weapons is in convincing your neighbors that you have them.
I assumed 2 neutrinos per fission (about 100 MeV per neutrino) and 200 m^2 for the cross sectional area of Kamiokande (to find the number of steradians it subtends). It's sort of awkward to write it all out, but heres the whole proportionality thing with all the units, so you can check that they all cancel and the 4pi is in the right place...
30 kT * 4e12 J/kT / (200e6 eV/fission) / (1.6e-19 J/eV) * ( 200 m^2 ) / ( 1e12 m^2 ) / 4 / 3.14159 * 2 neutrinos/fission = 12e13 neutrinos
Evil slashcode, evil! That was 1013 (10^13 in ASCII)
Seismic results can be faked with conventional explosives -- 30,000 tons of TNT is expensive but can be amassed even by a small nation like North Korea.
However, the world's most sensitive neutrino detector (Kamiokande) is under 1,000 km away. If the North Koreans detonated a 10-30 kiloton device, several times 1013 neutrinos from it should have passed through Kamiokande. I don't know Kamiokande's exact quantum efficiency, but it should be able to detect a pulse like that. After all, it detected Supernova 1987-A...
How zippy is your machine? An XP 1700 wita a gigabyte of RAM is capable of simulating regional weather patterns in real time, or of calculating about 10,000 lunar orbital injection trajectories per second, or of playing 100 competition chess games simultaneously, or of analysing and controlling traffic patterns in a mid-sized city core.
So, er, your 1700 *is* a super system. With that much horsepower at your disposal, you shouldn't have to wait more than 0.1 second to start up your favorite application. If you notice *any* lag before any dialog box comes up, you should be questioning why.
Heh. There goes my karma. Sorry for the grave misspelling...
/V1c3 d@%
h4\/3 4
Ph33r m% l337 leetspeak 5k1||z d00d. J00 h4\/3 833N 7R0||Z0r3d. J00 h4\/3 l057. h4\/3 4 |V1c3 d@%.
I haven't watched Roulette in a few years, but traditionally the bets are placed while the ball is rolling around the perimeter of the wheel. That eliminates the possibility that the croupier could manipulate or time his toss based on the bets people have made. So, yes, that is the whole point of TFA: a measure that was adopted to address a security concern with gambling (the timing of the betting) makes it possible to defeat the chance element another way (by using numerical simulation to predict where the ball will land, based on early observation of its path around the wheel).
The "game" aspect of roulette is to try to guess on which number (or segment of the wheel) the ball will land. The point of roulette is that it is exceedingly difficult to guess the number based on the initial few seconds in which the ball is rolling around the top. However, with modern computers it can be done in time to place a real bet.
Citation please? The mainstream media seem to think it was some combination of Rove and Scooter Libby, neither of whome was a disgruntled employee.
I'm not so sure what you're getting at here -- but remember all those months of claiming that Saddam Hussein supported Al Qaeda, and was developing weapons of mass destruction to launch at us? Remember how the loyal opposition was vilified for calling bullshit? We know how the WMD search turned out, and we know that U.S. intelligence knew at the time how it would turn out. Now a U.S. Senate report points out that, in fact, there was no link at all between Hussein and Al Qaeda, and that the Bush administration knew it.
There was no reason at all to go into Iraq. Bush lied. Over 2,000 of our young men died, and you personally spend $40,000 (and counting) for that lie. Sorry to bring you the harsh news, dude.
If W had followed through on his promises of humility and gentle government, yes, I think he could have been a "uniter". But instead he showed a pattern of disregarding anything he didn't want to hear, and undid a great many things that took a great many years to achieve. He had a big chance to unite the country, shortly after 9/11 when we all pulled together anyway -- but used that opportunity instead to try to make our homeland a torturing, wiretapping police state.
Putting aside any lawyerly evasions, it's ludicrous to compare a lie about a blowjob with a lie used in the leadup to a wasteful and unjustified war, with all the suffering, death, and costs (both societal and financial) that it entails. So far, over 2,000 good men have died more or less in vain for the sake of a repeated lie (that there was a clear and present reason to invade Iraq, rather than finishing the job in Afghanistan).
Yes, and it's perhaps the most effective and insidious type of lie. Deliberately denying the evidence of one's own senses (in this case, one's own cabinet and intelligence wings) is self-deception. Wilfully doing so is lying. It's much easier to lie to others if you first convince yourself.
Yes, if you have good reason to believe otherwise but choose not to heed those reasons.
When actions and rhetoric disagree so strongly, it is indeed hard to conclue otherwise. Rather than turn this into a lengthy rant, I'll follow one example: If the Iraqi conflict were genuinely as important to our safety as the neocons imply, we should have a draft and a mobilized military-industrial complex, as we did during WWII (which, recall, lasted just 3.5 years). The neocons know that would be political suicide, because Iraq just isn't that important -- so they tried to do the job half-assed, with the same result they had 35 years earlier in Viet Nam -- an unhappy population, a growing insurgency, and no exit strategy. They knew (or at least ha seen reports saying) that Iraq had nothing to do with Al-Qaeda, that they had no WMDs, and that they were no current threat, but they still pushed that rhetoric and spent over $40,000 of your money (and another $40k from every man, woman, and child in the nation) on a pig in a poke.
W ran on the platform of being a uniter who would work hard to bring everyone together. Am I the only person who remembers those campaign speeches? We appear to be about as divided as we've ever been, as a nation.
I've heard this meme (that "the Democrats also steal a lot of elections") a lot lately but I have not seen anyone substantiate it. I don't recall anyone getting up in arms about the process of the Clinton elections, though certainly there were people upset that he won.
Does anyone have anything other than innuendo on this talking point? It sounds a little too much like a Rove snowjob to me -- I hear the talking point a lot from different sources but never any deeply resourced, specific complaints such as RFK aired.
... influencing the outcome of the game (e.g. with a magnet) is cheating. There's nothing in the rules of Roulette that says "The gamblers shall not attempt to predict when and where the ball lands" -- or, at least, not the last time I checked. Roulette is simply flawed in an era when palm-sized computers are ubiquitous. Similarly, blackjack can be beaten by card-counting, but card-counting is not cheating, it's good memory.