A thorium reactor does not require the expensive hard-to-make enriched uranium fuel rods that conventional pressurized water reactors and boiling water reactors do.
No, it requires special alloys for piping the molten salt (fluorides are still corrosive), may require replacing the graphite moderator every 4 years (keep in mind not to allow moisture to come in contact with the salt, HF is nasty for your pipes no matter what material you'd be using), raises challenges in regards with by-product processing. citation if one needs it.
These guys (which played with MSR since '50-es) are saying, while the reactor accident risks are decreased, the processing accident risks are increased (see page 13-15).
We both agree that G is a constant. However I believe that a watt balance works on the principle mgv = UI.
Can make the experiment g-insensitive by using the torsion balance and keeping the g orthogonal. google for "torsion balance" and "Cavendish"
The rotating weight on a spring is a brilliant idea, but in a real experiment you would have to account for the gravitational force vector on the weight which gets you back to g again.
No, just keep the rotation plane orthogonal on the g vector and make all the measurements on the horizontals - thus letting the gravitation on vertical and measuring only the inertial forces due to rotation in the horizontal plane. At the most you'll need to account for the gravitation of the moon if you want exquisite precision, but if you arrange the experiment when the moon is "on the vertical" you can cancel that too.
Theoretically, it doesn't need to rely on knowing g (Earth-specific), but G (gravitational constant).
In short if either g or the reference kilogram is constant, a watt balance definition is viable. But that's not the case.
Not g, but G=6.67300 × 10-11 m3 kg-1 s-2. Can be measured irrespective of the presence of g = 9.81 m/s2, but it is awfully hard to get enough precision (the gravitational field being so weak) - you know, like using a torsion balance.
Alternatively, since measuring distances, angles, time and electric currents can be done with better precision, one can substitute "measuring 1 kg of substance" with "measuring 1 kg of inertial mass" (centrifugal force countered by a spring, use a watt balance to generate a force to compensate the elongation of the spring - so that you don't need to rely on the spring's elastic constant). Granted, the measurement is as good as the hypothesis of "inertial mass=gravitational mass", but if you take the theory of relativity as valid, the hypothesis is good.
Why should it come as a surprise to anyone to find out that they're still doing it?
...to curb abuses we should prosecute Agents, Special Agents, SACs and directors when they're involved in illegal activity instead of wringing our hands like we do now.
Does EFF sounds to you as an organization with a focus on "wringing their hands"? Seems to me the first thing one needs to do is to see if (you "when") illegal activity occurred, wasn't this what EFF has set itself to do in this instance?
The Watt balance relies on knowing g, which is not a constant.
Right.
Theoretically, it doesn't need to rely on knowing g (Earth-specific), but G (gravitational constant). Practically, I don't know which is harder: counting atoms with enough precision or measuring G with enough precision.
No, but since 1950 was 60 years ago, the majority of people have were born since then, and all of them have spent over half their life living in post 1950.
I was just trying to offer some clues for your "puzzlement that people continue to act as surprised". My point: I suppose you aren't surprised that new generations keep coming and, not having the whole knowledge/experience of a born-'50-er, they might be genuinely surprised. Even if only acting, I'm still happier with this faked reaction than I am with the "and how's this new?" one.
Speaking for myself (a whole 15 years younger), I'm puzzled rather by "Would the politicians never learn?"
Practical problems with controlling the measuring conditions, I guess.
These practical problems also arise when you want to use the definition of a kilogram (or a derived unit) in any real experiment. This is unavoidable: our ability to measure will always be constrained by technology (and in some cases the Planck Constant).
By defining the kilogram as a multiple of something that (probably) doesn't change (like Carbon 12 atoms) we only have one error term arise... when we use the definition of the kilogram in an experiment.
Averaging is worse, this I agree with. My argument: you need to take care about two experiments, twice as many occasions for something to go wrong.
But, speaking about precision and the possibility of control: what's wrong with the Watt balance alone? Maybe I'm wrong, but seems to me as easier to control and replicate the measurements to re-obtain the value for the unit. Besides advances in electronics (for increased precision, if/when needed) are more likely than advances in counting something on the order of 10^23 particles (which should be identical).
But if the EFF is so Tech and New Media savvy, it didn't occur to them that they might want to release this information...
Who said that EFF is (or need to be) media savvy?
Just what happen to the position "news of problems need to travel the fastest?" What if the first "slow news day" will come only in 1 year from now?
Should everything be subordinated for the "news-tainment consumers" market segment? Should an organisation focused on "protecting your digital rights" be dumbed down to the level of the society instead of attempting to raise the society to its level?
In every decade since I was born (in the early 50's), the FBI has engaged in egregious misconduct, although sometimes we didn't find out about it until years later. I am amazed that they have any credibility left, and puzzled that people continue to act surprised when these things come to light.
Is everybody in U.S. of A born in the '50?Are there extensive history classes on FBI abuses, perhaps ending with an exam, on the topic?
And your point is? Here's the list of extremes, but feel free to explain your position:
1. the FBI must be dismantled as an active organisation
2. the FBI is good and dandy... get over it, there's no right to privacy for anyone.
It matters if the number of violations is a significant percentage of investigations...
All systems have errors. that has to be expected, it has to be anticipated: whatever you put in place will have errors: thefts, abuses, breakdowns.
It's like the air you breath: it ain't pure. If you want to breathe, there's gonna be some bad stuff in there, always. Has to be.
Perfect cleanliness, being quite next to god, doesn't exist.
It doesn't take much (even when speaking percentage) for something to stink. It takes only 0.00047 ppm of H2S for 50% of humans to detect a "rotten eggs"-like smell, it takes 100–150 ppm for the optical nerve be paralyzed, it takes 800 ppm for 50% of the humans be dead in 5 mins (should I go ahead an explore hydrogen cyanide?).
In the matter of democracy and freedoms, even a small percentage of "mistakes" (even if when not outright abuses) can be deadly or seriously crippling for the society.
Like in terms of "mass of a photon for a well defined electronic transition of a certain element"? Scientific solutions exists in heaps, the difficulty is to measure it precisely, control the "experiment" (including the environ) well enough, make the "experiment" reasonable easy to reproduce... all of them pertain to technology now rather than to science.
There's a perfectly useful Atomic Mass Unit already defined: the dalton. http://en.wikipedia.org/wiki/Atomic_mass_unit
Why not define the kilogram in terms of a given number of Carbon 12 atoms?
Or if that is not stable enough, define it in terms of the electron rest mass. That's been stable for at least half the age of the universe.
Practical problems with controlling the measuring conditions, I guess. Mass unit based on the number of particles: exactly count the number of particles, make sure they are of the correct type (isotopes), keep particles together for the duration of experiment (hard to do with electrons), eliminate the influence of environ (buoyancy, gas adsobtion)... going to extreme, control the temperature (more energy, more mass).
How about working out the number of grams from one mol of Oxygen(?) atoms? If they all have an atomic mass of ~16 you know they're about 16 grams.:o
Not controllable enough. How you make sure that all atoms are of the "standard isotope" type and you have the correct number of atoms? What "environ conditions" (Buoyancy? gas adsorbtion?) How do know the number of atoms in your "definition" sample doesn't vary over time? Even if pushing to the extreme: what temperature should it have/what predominant electronic state? (higher inner energy, higher mass). This is where the definition based on the Watt balance is, in my opinion, easier to control/reproduce.
I'd tend to agree, but Ford and Microsoft are both rather good examples of companies that saw their pervasive quality issues and made effective changes to mitigate that problem.
Seriously, seen a new Ford lately?
Please, wake me up when they'll start to take changes to prevent quality issues instead of mitigating them, will you? Thanks.
Slashdot Mirror
Ok, seriously, who the fuck uses cold fusion anymore?
...aggravating factor... on a web server on Windows.
A thorium reactor does not require the expensive hard-to-make enriched uranium fuel rods that conventional pressurized water reactors and boiling water reactors do.
No, it requires special alloys for piping the molten salt (fluorides are still corrosive), may require replacing the graphite moderator every 4 years (keep in mind not to allow moisture to come in contact with the salt, HF is nasty for your pipes no matter what material you'd be using), raises challenges in regards with by-product processing. citation if one needs it.
These guys (which played with MSR since '50-es) are saying, while the reactor accident risks are decreased, the processing accident risks are increased (see page 13-15).
... for the "China syndrome"?
"A strong CIDR please, I'm exhausted"
We both agree that G is a constant. However I believe that a watt balance works on the principle mgv = UI.
Can make the experiment g-insensitive by using the torsion balance and keeping the g orthogonal. google for "torsion balance" and "Cavendish"
The rotating weight on a spring is a brilliant idea, but in a real experiment you would have to account for the gravitational force vector on the weight which gets you back to g again.
No, just keep the rotation plane orthogonal on the g vector and make all the measurements on the horizontals - thus letting the gravitation on vertical and measuring only the inertial forces due to rotation in the horizontal plane. At the most you'll need to account for the gravitation of the moon if you want exquisite precision, but if you arrange the experiment when the moon is "on the vertical" you can cancel that too.
Troll.
As if Apple was the only one using those things.
Failure.
As if others doing the same make this "same" more ethical.
Then there's the Zeeman effect to mess with your electronic transitions :P
Let's not skip over the Stark effect, everybody knows you need an electrical field to generate a magnetic one :P
what advantage does this technology hold over trains?
Is recently patented?
I am thus angry and skeptical, and frustrated that more others are not.
Shared feelings - same on my side.
On the matter of form, better expressed now than the castrated original "puzzled" term you used.
So frankly I do not see how you can achieve 99.99+ purity to do anything useful with it.
My bad: next time I'll explicitly put a *wink*.
Theoretically, it doesn't need to rely on knowing g (Earth-specific), but G (gravitational constant).
In short if either g or the reference kilogram is constant, a watt balance definition is viable. But that's not the case.
Not g, but G=6.67300 × 10-11 m3 kg-1 s-2. Can be measured irrespective of the presence of g = 9.81 m/s2, but it is awfully hard to get enough precision (the gravitational field being so weak) - you know, like using a torsion balance.
Alternatively, since measuring distances, angles, time and electric currents can be done with better precision, one can substitute "measuring 1 kg of substance" with "measuring 1 kg of inertial mass" (centrifugal force countered by a spring, use a watt balance to generate a force to compensate the elongation of the spring - so that you don't need to rely on the spring's elastic constant).
Granted, the measurement is as good as the hypothesis of "inertial mass=gravitational mass", but if you take the theory of relativity as valid, the hypothesis is good.
Why should it come as a surprise to anyone to find out that they're still doing it?
...to curb abuses we should prosecute Agents, Special Agents, SACs and directors when they're involved in illegal activity instead of wringing our hands like we do now.
Does EFF sounds to you as an organization with a focus on "wringing their hands"?
Seems to me the first thing one needs to do is to see if (you "when") illegal activity occurred, wasn't this what EFF has set itself to do in this instance?
The Watt balance relies on knowing g, which is not a constant.
Right.
Theoretically, it doesn't need to rely on knowing g (Earth-specific), but G (gravitational constant). Practically, I don't know which is harder: counting atoms with enough precision or measuring G with enough precision.
Yes, it is. The good news: unlike silicone, you can buy some of it and make your own transistors... errr... isn't it?
No, but since 1950 was 60 years ago, the majority of people have were born since then, and all of them have spent over half their life living in post 1950.
I was just trying to offer some clues for your "puzzlement that people continue to act as surprised". My point: I suppose you aren't surprised that new generations keep coming and, not having the whole knowledge/experience of a born-'50-er, they might be genuinely surprised. Even if only acting, I'm still happier with this faked reaction than I am with the "and how's this new?" one.
Speaking for myself (a whole 15 years younger), I'm puzzled rather by "Would the politicians never learn?"
Practical problems with controlling the measuring conditions, I guess.
These practical problems also arise when you want to use the definition of a kilogram (or a derived unit) in any real experiment. This is unavoidable: our ability to measure will always be constrained by technology (and in some cases the Planck Constant).
By defining the kilogram as a multiple of something that (probably) doesn't change (like Carbon 12 atoms) we only have one error term arise... when we use the definition of the kilogram in an experiment.
Averaging is worse, this I agree with. My argument: you need to take care about two experiments, twice as many occasions for something to go wrong.
But, speaking about precision and the possibility of control: what's wrong with the Watt balance alone? Maybe I'm wrong, but seems to me as easier to control and replicate the measurements to re-obtain the value for the unit. Besides advances in electronics (for increased precision, if/when needed) are more likely than advances in counting something on the order of 10^23 particles (which should be identical).
But if the EFF is so Tech and New Media savvy, it didn't occur to them that they might want to release this information...
Who said that EFF is (or need to be) media savvy?
Just what happen to the position "news of problems need to travel the fastest?" What if the first "slow news day" will come only in 1 year from now?
Should everything be subordinated for the "news-tainment consumers" market segment? Should an organisation focused on "protecting your digital rights" be dumbed down to the level of the society instead of attempting to raise the society to its level?
In every decade since I was born (in the early 50's), the FBI has engaged in egregious misconduct, although sometimes we didn't find out about it until years later. I am amazed that they have any credibility left, and puzzled that people continue to act surprised when these things come to light.
Is everybody in U.S. of A born in the '50?Are there extensive history classes on FBI abuses, perhaps ending with an exam, on the topic?
And your point is? Here's the list of extremes, but feel free to explain your position:
1. the FBI must be dismantled as an active organisation
2. the FBI is good and dandy... get over it, there's no right to privacy for anyone.
It matters if the number of violations is a significant percentage of investigations... All systems have errors. that has to be expected, it has to be anticipated: whatever you put in place will have errors: thefts, abuses, breakdowns. It's like the air you breath: it ain't pure. If you want to breathe, there's gonna be some bad stuff in there, always. Has to be. Perfect cleanliness, being quite next to god, doesn't exist.
It doesn't take much (even when speaking percentage) for something to stink.
It takes only 0.00047 ppm of H2S for 50% of humans to detect a "rotten eggs"-like smell, it takes 100–150 ppm for the optical nerve be paralyzed, it takes 800 ppm for 50% of the humans be dead in 5 mins (should I go ahead an explore hydrogen cyanide?).
In the matter of democracy and freedoms, even a small percentage of "mistakes" (even if when not outright abuses) can be deadly or seriously crippling for the society.
In that case, our government seems to be sending a mixed message by adding the internet kill-switch back into proposed legislation...
Sensationalist headlines aside, care to point out where the aforementioned bill says anything about shutting down communications?
Why does it need to be a quotation from the bill? wikileaks.org suddenly not resolving at a certain moment isn't enough of an example?
Like in terms of "mass of a photon for a well defined electronic transition of a certain element"?
Scientific solutions exists in heaps, the difficulty is to measure it precisely, control the "experiment" (including the environ) well enough, make the "experiment" reasonable easy to reproduce... all of them pertain to technology now rather than to science.
There's a perfectly useful Atomic Mass Unit already defined: the dalton. http://en.wikipedia.org/wiki/Atomic_mass_unit Why not define the kilogram in terms of a given number of Carbon 12 atoms?
Or if that is not stable enough, define it in terms of the electron rest mass. That's been stable for at least half the age of the universe.
Practical problems with controlling the measuring conditions, I guess.
Mass unit based on the number of particles: exactly count the number of particles, make sure they are of the correct type (isotopes), keep particles together for the duration of experiment (hard to do with electrons), eliminate the influence of environ (buoyancy, gas adsobtion)... going to extreme, control the temperature (more energy, more mass).
How about working out the number of grams from one mol of Oxygen(?) atoms? If they all have an atomic mass of ~16 you know they're about 16 grams. :o
Not controllable enough.
How you make sure that all atoms are of the "standard isotope" type and you have the correct number of atoms? What "environ conditions" (Buoyancy? gas adsorbtion?) How do know the number of atoms in your "definition" sample doesn't vary over time? Even if pushing to the extreme: what temperature should it have/what predominant electronic state? (higher inner energy, higher mass).
This is where the definition based on the Watt balance is, in my opinion, easier to control/reproduce.
I'd tend to agree, but Ford and Microsoft are both rather good examples of companies that saw their pervasive quality issues and made effective changes to mitigate that problem.
Seriously, seen a new Ford lately?
Please, wake me up when they'll start to take changes to prevent quality issues instead of mitigating them, will you? Thanks.