Re:The Davy Crockett Tactical Battlefield Warhead
on
Fission in a Box
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· Score: 1
I'm pretty sure there's no tritium in a W54 warhead (the business end of a Davy Crockett). Something producing.01 kT to 1 kT certainly doesn't need to mess around with fusion. Simple Pu-239 fission will work just fine. To answer a previous question about critical mass, most fission warheads contain what would normally be considered a subcritical mass of fissile material. This is usually a small sphere, surrounded by carefully designed chemical explosives. When the chemical explosives are detonated, they compress the sphere to the point that critical mass drops below the mass present, and *boom*.
The Davy Crockett was a wholly ridiculous weapon anyway. The thing could only get the warhead about a mile from the launch site (For the 120mm launcher, that is. The 155mm launcher could make about 2.5 miles). Actual use would have probably been well inside that range, due to accuracy concerns. Firing procedure would have been something like this:
1.) Aim weapon at target.
2.) Dig hole deep enough to hide in.
3.) Fire weapon.
4.) Jump in hole, pray to preferred deity.
Tokamak reactors don't produce as many free neutrons as one might suspect. In every design I've seen, the fusion chamber is surrounded by a thick jacket of liquid lithium. When a neutron hits Li-6, it produces one tritium atom and one helium atom. The tritium is sent into the reactor as fuel, and the helium is disposed of. Li-7 is much more common than Li-6, but neutron capture by Li-7 just leads to 2 helium nuclei by an intermediate beta decay. Both isotopes have pretty big neutron capture cross-sections, so a thick enough jacket will absorb quite a lot of neutrons.
The lithium also serves as the coolant, similar to the water in a typical fission reactor. So the only thing that is subject to high levels of neutron activation is the innermost wall of the coolant system. You wouldn't want to spend much time near one, but I don't think it would produce any more free neutrons per kWh than a fission plant does (with equivalent shielding).
One fun use for high energy beta emitters is to put them in a large container of water (or encase it in glass or plastic), turn out the lights, and enjoy the pretty blue glow. Collect enough hignly unstable fission fragments from a reactor, and you can have your very own Cerenkov night-light!
Really, though, I agree with the idea of burying the nastier stuff on the low side of a subduction fault. By the time any of that rock resurfaces, the radionuclides will be long decayed.
You make some valid points, but there are some problems with applying them to South Africa. There is virtually no market for AIDS drugs in South Africa at current prices. The vast majority of people with the disease would have to work for several weeks to afford one day's worth of treatment. The choice of being broke or dead is not even available to these people; they're already broke. The choice is being broke, dead, and not pissing off the drug companies, or being broke, alive, and irking large American corporations.
Profits from drug sales are definitely essential to researching new treatments. The important thing is that no significant profit is currently being made in South Africa, so there's no profit to be immediately lost by selling those patients drugs at low cost. The only way for them to lose money is if the low-cost drugs take the place of high-cost versions in markets that can actually afford the higher priced drugs. The drug companies are not sacrificing those thousands or millions of lives for the sake of research into future treatments. They are not even doing it to protect next year's bottom line. They are allowing every one of those people to die simply to make it clear that they control the prices, and they'll change them if and only if they want to.
I do have to agree completely with your last point, though. Education and prevention are more important than anything else.
My thought was that the quarks in the neutron star, not being confined to a nucleus, would have sufficient freedom to absorb or emit longer wavelengths. But I guess that even though they exist a very large volume, each individual quark still has a fairly well determined position, and hence has widely separated energies.
The title of 'diamond' is highly suspect. Matter at the middle of a neutron star doesn't even bother forming nuclei, much less atoms or crystals. What they're saying is that the quark soup in a neutron star was previously thought to contain a few electrons mixed in, which would absorb light. It now seems that strange quarks are more stable in that environment than previously thought, which eliminates the requirements for electrons in that area. The result is a whole hell of a lot of mass in a small volume that doesn't interact with light all that much. So if you managed to isolate the core of a neutron star (completely impossible), without changing its optical properties (even more impossible), you'd have a transparent object the size of a small city, weighing as much as a small star.
The fact that strange quarks may be more stable than previously thought under some circumstances is interesting. The fact that some portion of the middle of a neutron star is transparent is almost completely useless speculation. Ignoring that, there's still the problem that nothing in the article remotely resembles a diamond from a scientist's point of view.
What I'm not so sure about is why it is supposed to be transparent. I know that all macroscopic interaction we observe with light is through electrons, but I thought that was just because the nuclei take up too little space to be noticed. When you have a star core composed of quarks, even without electrons mixed in, I'd expect electromagentic interaction with the quarks themselves to prevent light from travelling any distance. Or are the quarks bound tightly enough that they can't absorb or emit visible wavelengths? IANANPY (I am not a nuclear physicist, yet), so I'm not so sure about that one.
I can see why dark matter and dark energy seem a bit incredible. They go completely against common sense. But so does relativity, and nearly all of quantum mechanics. Those theories were developed to explain observations, and they happened to make some odd predictions as well. Early on, the public generally scoffed at those theories because their predictions were contradictory to common sense.
The ideas of dark energy and matter were also invented to explain observations. So for all you people who keep saying "Dark matter/dark energy/[insert theory here] MUST be wrong because my high-school physics education says so, and I read one book that Hawking dumbed down enough that I thought I understood it, so those people who've spent half their lives studying this stuff must have their heads in their asses," I have a challenge:
Come up with a better explanation.
Come up with a mathematically consistent model to represent your explanation.
Get it published in a moderately well-known scientific journal (New Scientist does NOT count).
Get it past the first hour of peer review semi-intact.
Then you can tell everybody that the other theory is wrong. Until then, your words are no more valid than those of the preacher telling you why evolution MUST be wrong.
The Tevatron has been throwing particles at each other since 1983. The detectors are new, having been constructed during a long period of downtime, and the experiments are new. There's also a new particle injection system, which will allow higher particle energies and/or beam intensities than before. Their page isn't too clear about which aspect of the accelerator is improved by the new injector, but I suspect it's intensity, not energy. Still, they're probably having fun with their new toys. I have a feeling that the RHIC will be even more fun, though.
Ugh. There is no 'e' in the name of the element that microchips are made of. I realize that silicone can be interesting in certain applications, but it bears no relevance to this story.
That doesn't work so well with e-mail addresses. They tend to filter out extraneous punctuation. I think duhbya works nicely, sort of a take-off on Scott Adams' inDUHviduals.
Come on... Have some fun with it! My standard was slickwilly@whitehouse.gov, but that changed to duhbya@whitehouse.gov with the election. root@127.0.0.1 usually works, too.
Then you can also go for the movie references, like werner_brandes@playtronics.com, etc. I'm sure you can find something more creative than these, though.
Grow your own clone, preferably without the brain...
You'd be surprised how easy that is with some people.
Seriously, though, it'd be pretty damn hard to keep the spare body alive long enough to be useful. Ends up running into the same technological impossibilities as the plot of 6th Day (God-awful movie - I'm still kinda pissed at my roommate for suckering me into watching it. That time could have been much better spent playing CS.)
>Water molecules are significantly smaller than 12cm.
Really? The ones we had in high school chem class were about 20 cm across, with the red wooden ball connected to the two white wooden balls by little sticks.
What? Those weren't actual size?! That explains why I never saw the wooden balls in my tap water.
The trouble with metal is when it forms most of a loop, but not a whole one. The electromagnetic field tries to induce a current in anything conductive, and currents must flow in loops (in the long term, anyway). A partial loop will get a really big potential difference across its length, and will then arc across the ends, completing the loop. The reason you don't want to put a crumpled ball of aluminum foil in your microwave is that you can find dozens of incomplete loops in it. This causes a bunch of arcing and other bad things.
A solid disc of metal, like the bottom of an orange juice can, causes no problems whatsoever in the microwave. Plenty of current is induced in it, and it will warm up from resistive heating, but it won't arc. Just don't leave it in too long, or that resistive heating can become problematic.
The X-Files had that fungus? Cool. I don't watch the show, but that sounds suspiciously similar to a certain fungus in Space Quest II. As the game relates it, your last thought as your body begins to get digested is "Wow! Check out the colors, dude!"
This whole 'electromagnetic force' crap is just that... crap. "We can't explain what electricity is so let's invent 'electromagnetic force' containing 'charges'. Nobody will ask us what the fuck it is, or ask for proof of existance because were scientists and are not open to questioning." (bad punctuation copied from parent)
May as well be the same thing. The only difference is that electrodynamics has been around long enough for its predictions to be well verified (at least in low-energy, macroscopic cases). Scientific models are invented to explain observations. If you can come up with an explanation of why these supernovae are observed to have the redshift and luminosity they do, without fucking up every other aspect of physics, in a manner consistent with other physical laws, you're welcome to do so.
If you actually take some physics courses, you might find out that scientists' work is more open to questioning than pretty much anyone else's.
Everybody who thinks they have any hope of understanding them asks about new theories. Everybody tries to poke holes in them. The ones that survive make it into textbooks. This particular theory has not existed for long enough to be properly investigated, but it looks pretty promising. Just because it seems counterintuitive doesn't mean its wrong. (Do you have any idea how counterintuitive quantum mechanics seems? Turns out it's a pretty damn good approximation.)
I was gonna post an explanation here, but then I decided to check that "1 reply below your current threshold," and found a decent explanation that had been modded down to "-1, Offtopic." Normally, I'm not one to bitch about moderation. But this was a plain, accurate, on-topic reply to an on-topic post, and this was a blatant abuse by that moderator. So if you want to see the reply, just click that link, and hope that moderator meets a humorously unpleasant end in the near future.
The whole point of science is to expand its scope indefinitely. There are plenty of things which fall outside the realm of current scientific explanation. But 500 years ago, there were a hell of a lot more. Your same arguments were used to try to discourage nearly every scientist in history from his/her research. They were told that what they were researching was God's territory, and it is not the place of mere humans to investigate it or try to explain it. A while later, their explanations become part of the general consciousness, and are pretty much deviod of religious implications. (There are exeptions, of course, such as the people who claim "[Insert Well Accepted Theory Here] MUST be false because it conflicts with [Insert Irrational Belief Here]!")
Science has already taken light, Earth, plants, animals (including humans), and most of the heavens out from under the cloak of "God did it." We're working on the details of the rest of the heavens, as each new observation forces us to rework our theories to more accurately match reality. Science's explanations will never be perfect. But they will be much more complete and useful than "God did it."
"There is a theory that states that if the purpose of the universe were ever discovered it would immediately be replaced with something even more bizzarely inexplicable. There is a second theory that states that this has already happened"
Heisenburg's uncertainty relation for energy-time measurements only requires that the uncertainty be greater than hbar/2, or 5.27e-35 J*s. I'm not sure what kind of units omega is measured in, but I somehow doubt that 5.27e-35 can make the difference between 0.3 and 1. But then, I haven't studied general relativity in any depth whatsoever, so I may be talking out of my ass here.
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The Davy Crockett was a wholly ridiculous weapon anyway. The thing could only get the warhead about a mile from the launch site (For the 120mm launcher, that is. The 155mm launcher could make about 2.5 miles). Actual use would have probably been well inside that range, due to accuracy concerns. Firing procedure would have been something like this:
1.) Aim weapon at target.
2.) Dig hole deep enough to hide in.
3.) Fire weapon.
4.) Jump in hole, pray to preferred deity.
The lithium also serves as the coolant, similar to the water in a typical fission reactor. So the only thing that is subject to high levels of neutron activation is the innermost wall of the coolant system. You wouldn't want to spend much time near one, but I don't think it would produce any more free neutrons per kWh than a fission plant does (with equivalent shielding).
The sun is hot (It is so hot that everything on it is a gas: iron, copper, aluminum, and many others.)
The sun is large (If the sun were hollow, a million Earths could fit inside. And yet, the sun is only a middle-sized star.)
But, at least
The sun is far away (About 93 million miles away, and that's why it looks so small.)
And even when it's out of sight
The sun shines night and day
Apologies (and thanks) to TMBG.
Really, though, I agree with the idea of burying the nastier stuff on the low side of a subduction fault. By the time any of that rock resurfaces, the radionuclides will be long decayed.
Profits from drug sales are definitely essential to researching new treatments. The important thing is that no significant profit is currently being made in South Africa, so there's no profit to be immediately lost by selling those patients drugs at low cost. The only way for them to lose money is if the low-cost drugs take the place of high-cost versions in markets that can actually afford the higher priced drugs. The drug companies are not sacrificing those thousands or millions of lives for the sake of research into future treatments. They are not even doing it to protect next year's bottom line. They are allowing every one of those people to die simply to make it clear that they control the prices, and they'll change them if and only if they want to.
I do have to agree completely with your last point, though. Education and prevention are more important than anything else.
My thought was that the quarks in the neutron star, not being confined to a nucleus, would have sufficient freedom to absorb or emit longer wavelengths. But I guess that even though they exist a very large volume, each individual quark still has a fairly well determined position, and hence has widely separated energies.
Well shit! There go my plans for the weekend.
The fact that strange quarks may be more stable than previously thought under some circumstances is interesting. The fact that some portion of the middle of a neutron star is transparent is almost completely useless speculation. Ignoring that, there's still the problem that nothing in the article remotely resembles a diamond from a scientist's point of view.
What I'm not so sure about is why it is supposed to be transparent. I know that all macroscopic interaction we observe with light is through electrons, but I thought that was just because the nuclei take up too little space to be noticed. When you have a star core composed of quarks, even without electrons mixed in, I'd expect electromagentic interaction with the quarks themselves to prevent light from travelling any distance. Or are the quarks bound tightly enough that they can't absorb or emit visible wavelengths? IANANPY (I am not a nuclear physicist, yet), so I'm not so sure about that one.
void life(){
eatLike(pig);
getFat();
while(true){
getHeartDisease();
growOrganFrom(heart,fat);
transplant(heart);
}}
The ideas of dark energy and matter were also invented to explain observations. So for all you people who keep saying "Dark matter/dark energy/[insert theory here] MUST be wrong because my high-school physics education says so, and I read one book that Hawking dumbed down enough that I thought I understood it, so those people who've spent half their lives studying this stuff must have their heads in their asses," I have a challenge:
Come up with a better explanation.
Come up with a mathematically consistent model to represent your explanation.
Get it published in a moderately well-known scientific journal (New Scientist does NOT count).
Get it past the first hour of peer review semi-intact.
Then you can tell everybody that the other theory is wrong. Until then, your words are no more valid than those of the preacher telling you why evolution MUST be wrong.
The Tevatron has been throwing particles at each other since 1983. The detectors are new, having been constructed during a long period of downtime, and the experiments are new. There's also a new particle injection system, which will allow higher particle energies and/or beam intensities than before. Their page isn't too clear about which aspect of the accelerator is improved by the new injector, but I suspect it's intensity, not energy. Still, they're probably having fun with their new toys. I have a feeling that the RHIC will be even more fun, though.
Ugh. There is no 'e' in the name of the element that microchips are made of. I realize that silicone can be interesting in certain applications, but it bears no relevance to this story.
That doesn't work so well with e-mail addresses. They tend to filter out extraneous punctuation. I think duhbya works nicely, sort of a take-off on Scott Adams' inDUHviduals.
Then you can also go for the movie references, like werner_brandes@playtronics.com, etc. I'm sure you can find something more creative than these, though.
It was a bright, cold day in April, and the clocks were striking thirteen.
You'd be surprised how easy that is with some people.
Seriously, though, it'd be pretty damn hard to keep the spare body alive long enough to be useful. Ends up running into the same technological impossibilities as the plot of 6th Day (God-awful movie - I'm still kinda pissed at my roommate for suckering me into watching it. That time could have been much better spent playing CS.)
Really? The ones we had in high school chem class were about 20 cm across, with the red wooden ball connected to the two white wooden balls by little sticks.
What? Those weren't actual size?! That explains why I never saw the wooden balls in my tap water.
A solid disc of metal, like the bottom of an orange juice can, causes no problems whatsoever in the microwave. Plenty of current is induced in it, and it will warm up from resistive heating, but it won't arc. Just don't leave it in too long, or that resistive heating can become problematic.
The X-Files had that fungus? Cool. I don't watch the show, but that sounds suspiciously similar to a certain fungus in Space Quest II. As the game relates it, your last thought as your body begins to get digested is "Wow! Check out the colors, dude!"
May as well be the same thing. The only difference is that electrodynamics has been around long enough for its predictions to be well verified (at least in low-energy, macroscopic cases). Scientific models are invented to explain observations. If you can come up with an explanation of why these supernovae are observed to have the redshift and luminosity they do, without fucking up every other aspect of physics, in a manner consistent with other physical laws, you're welcome to do so.
If you actually take some physics courses, you might find out that scientists' work is more open to questioning than pretty much anyone else's. Everybody who thinks they have any hope of understanding them asks about new theories. Everybody tries to poke holes in them. The ones that survive make it into textbooks. This particular theory has not existed for long enough to be properly investigated, but it looks pretty promising. Just because it seems counterintuitive doesn't mean its wrong. (Do you have any idea how counterintuitive quantum mechanics seems? Turns out it's a pretty damn good approximation.)
I think I'll quit feeding this troll now.
I was gonna post an explanation here, but then I decided to check that "1 reply below your current threshold," and found a decent explanation that had been modded down to "-1, Offtopic." Normally, I'm not one to bitch about moderation. But this was a plain, accurate, on-topic reply to an on-topic post, and this was a blatant abuse by that moderator. So if you want to see the reply, just click that link, and hope that moderator meets a humorously unpleasant end in the near future.
Science has already taken light, Earth, plants, animals (including humans), and most of the heavens out from under the cloak of "God did it." We're working on the details of the rest of the heavens, as each new observation forces us to rework our theories to more accurately match reality. Science's explanations will never be perfect. But they will be much more complete and useful than "God did it."
- Douglas Adams
Heisenburg's uncertainty relation for energy-time measurements only requires that the uncertainty be greater than hbar/2, or 5.27e-35 J*s. I'm not sure what kind of units omega is measured in, but I somehow doubt that 5.27e-35 can make the difference between 0.3 and 1. But then, I haven't studied general relativity in any depth whatsoever, so I may be talking out of my ass here.
Shouldn't that be Wanted: Schrodinger's Cat. Dead and alive?