I fail to see how the export profit of of selling novelty horses that have mutated to grow horns on their heads would off-set the loss in GDP of not being able to live near those horses and rainbows..
I fear you are overlooking a very serious problem for the world elite: where are you going to find the nori for your sushi that *doesn't* glow-in-the-dark?
If you're serious, then no, they're not going to take advice from people who have the Hanford site and don't want to open that waste repository in Nevada what was it called..
If you're making a funny joke (
How about they ask the Americans for help? We have had a lot of experience with nukes, (...)
They *have* to pour more money in and clean it up. Japan is a very densely populated country. They can't all move out to "Japan 2.0" nextdoor, you know. If half of Honshu becomes uninhabitable for 300 years, where are they all going to live then?? Hokkaido?
Maybe because an analog computer is usually not a general purpose computer (except maybe for the Difference Engine, but in the picture on the Wikipedia page even that looks quite inventive to me).
Good point about not mounting the USB stick but using dd. Just take the length of the message then, dd the length to the first 3 bytes of the stick, followed by the message. Then it doesn't need to be mounted (can't even:-)
Maybe it is possible to create errors in the USB stick hardware though..
The laptop(s) don't have a graphical desktop; only minimal installation, + program to decrypt the message, + program to handle the USB stick insert/read/write/withdraw. The only actions with the laptop are: USB stick in, USB stick out after a minute. What you say with "autolaunch" is an insane idea, I haven't used Gnome in a long time but I can't imagine that Nautilus does this by default though.
The decryption laptop needs to be highly secure: stored in a safe, not connected to anything, no WiFi, only USB stick work. Because it has to be re-usable: it is the only thing that contains the private key (ok maybe print out the private key in the old-fashioned Commodore 64 "short hex lines with checksum" way and put it in a safe in another building and burn the printer).
When the message has been decrypted, and the decrypted message is written on the USB stick, you can read it on a computer with lesser security (is there a way to write-protect USB sticks physically, like the old-fashioned floppies?). This second computer just has to be mounted freshly from live CD and not connected to the network either. Even if the message triggers something bad, the state of the computer is not important: its function is to convey the message to Bob. (of course as you say e.g. xpdf or okular can be subverted to change the content of a particular decrypted message). Multiple redundancy here as well, then. Any PDF reader that gives a different message from the other ones is very very interesting for Bob, who knows not only what Alice probably wrote, but also what the PDF reader subverter has substituted.
Since it seems to me that multiple redundancy would work well, and would yield both the original message and the subverted one for comparison, I conclude that this Ken Thompson attack is unlikely to be performed in practice, because it would yield too much information about what the attacker wants you to read in case of a special trigger message. (i.e. okular has been subverted but xpdf hasn't; and only if the message was about Barney the Dinosaur. Let's see who committed the change to okular that caused this.)
It's fun to think about these things for a one-off, but I'd hate to stake my career on this kind of stuff.. I hope universities have classes for computer security protocols.
In my career, I've just had lectures from various people about how they did things, and one thing I remember is that most serious sysadmins have spent years deeply thinking about how they could secure their bank/pension fund/public works in the best way.
But don't forget that for the recent scandals, there is probably no technical solution. Slashdotters are techies so they want to find technical solutions to problems. But in some cases, the only thing you can and must do is VOTE when the time comes, and remember on that day how you felt and what you thought today or in the last few weeks. Don't get distracted in the meantime... good luck!
I thought there was recent research about the Ken Thompson hack, I haven't read it tyough.. something called double compilation iirc.. it was on the LWN site.
Maybe you can use multiple redundancy like they do in mission critical environments: copy the message to three different USB sticks, put one in one laptop with FreeBSD and the program written in FORTRAN compiled with gcc, one laptop with new Ubuntu Linux and the program written in C compiled with clang, one laptop with the dustiest Debian that still works on it and the program written in Java, etc; an odd number of laptops. And if a particular message differs in its decrypted result, you know that at least one of the laptops has screwed up or been subverted, *and you can compare the decrypted messages* (should give you interesting information).
With respect to back doors etc: the nature of the possible corruption from malfeasance is limited by the (narrow) nature of the result produced: a file on the USB stick (ok, for the next post by kiwikiwi, just dd the USB stick and put the length of the data in the first 3 bytes)
Unless there really exists a "halt and catch fire" opcode, the nature of the damage is limited to writing different bytes to the USB stick in response to a message that triggers the attacker's hidden program on the laptop, i.e. a decrypted message that doesn't say what Alice wanted to say to Bob but what the infiltrator who had subverted the gcc compiler wanted to say in response to that particular encrypted message (what's the letter for this ? I never got further than A, B and Eve).
The nature of the possible damage is limited, because the function of the laptop in the organisation is such that you only want to let it write to the USB stick. If it says "aww please, connect me to the internet for updates", burn it.
I really don't see the problem.. either it's an isolated laptop locked up in a safe (I believe certification authorities use this set-up) where the people authorised to use it use USB sticks to transfer messages/certificates to/from the isolated laptop. I don't see how this can go wrong. Viruses are only a problem on really braindead OSes like MS Windows; why on earth would you use an OS that tried to execute anything that arrives on a USB stick for Real Work(TM)? It's a bogeyman that just doesn't exist on most OSes; I'll eat my hat(*) if bog standard Linux or FreeBSD installations try to execute anything on a USB stick unless it's rebooted with that stick as boot medium
Or, you have a secured network, where every employee has two computers on the desk; one connected to the normal ethernet and one connected to the secure private *wired* ethernet network. The employees who have to sometimes work with sensitive data use only programs on the private network connected computer for this. Typing them in by hand, as you say. Anytime somebody reconnects a computer to the wrong colour network cable, somebody gets fired. In this case you wouldn't want the secure computers to have DVD drives or USB ports of course.
(*) Disclaimer: I don't really have a hat, and I'm (obviously?) not a real security professional. Any corrections welcome.
Preinstalled anti-virus could provide a mechanism to scan for certain keywords, identify the file as a "virus", and (depending on the settings) auto-submit a sample for "research".
That's brilliant! All the three-letter-organisation has to do is, if an encrypted document is stolen, tell the anti-virus company to flag its MD5 sum as "dangerous virus to be deleted on the spot and e-mail the T.L.O. about it". Oh wait a minute...
It's more nuanced: the Bundesamt für Sicherheit in der Informationstechnik (B.S.I.) says it *doesn't* warn agains Microsoft Windows 8, it only warns the (German) government not to use Microsoft Windows 8 in certain scenarios on computer hardware with TPM 2.0:
"Hierzu erklärt das Bundesamt für Sicherheit in der Informationstechnik (BSI):
Das BSI warnt weder die Öffentlichkeit, deutsche Unternehmen noch die Bundesverwaltung vor einem Einsatz von Windows 8. Das BSI sieht derzeit jedoch einige kritische Aspekte im Zusammenhang mit bestimmten Einsatzszenarien, in denen Windows 8 in Kombination mit einer Hardware betrieben wird, die über ein TPM 2.0 verfügt."
Then, they first say that you can go ahead and buy MS Windows 8 on a TPM computer, as long as you don't worry/care ("kümmern") about the security of that computer. (There must be use cases within national and other governments where it just doesn't matter so much that a computer is insecure).
In the next paragraph, If I read it correctly (German is not my first or second language), they warn against using MS Windows 8 on a TPM 2.0 computer in case where security is of value: for " die Bundesverwaltung und kritische Infrastrukturen", they warn for the dangers of D.O.S. attack and sabotage where both the hardware and software become unusable. You got to read it yourself if you don't like my crummy translation. Corrections welcome.
I interpret the end of the press message as: maybe one day there will be a TPM 3.0 spec with "(...) ein bewusstes Opt-In sowie die Möglichkeit eines späteren Opt-Outs (...)" and then the BSI would be happy again.
Luckily, the article shows a ray of hope, on the second page:
"(...) Laut Microsoft könnten die Hardware-Hersteller zudem durchaus Windows-Geräte bauen, in denen das TPM deaktiviert ist. Wer die volle Kontrolle über seinen Computer haben wolle, müsse eben ein solches Modell kaufen.
Falls die IT-Experten des Bundes keine solchen Geräte finden, die bezahlbar sind und auch sonst ihren Ansprüchen genügen, bleibt ihnen wohl nur der Weg, den zum Beispiel die Münchner Stadtverwaltung eingeschlagen hat. Auf deren Computern läuft ein Linux-Betriebssystem. Die schrittweise Umstellung von Windows auf Linux begann vor zehn Jahren und soll Ende 2013 abgeschlossen sein."
IOW this TPM 2.0 "default on at first boot" is not a problem as long as governments buy only computers with a trusted signed Linux kernel and system. Additional advantage is that it's cheaper.
I hadn't thought of that. That's a good point. But to forbid or reduce the landlord's profit would disincentivise(sp?) him/her to improve the house, and the end-user electricity prices aren't going down anymore. And the lower income brackets, who rent, have no money to spare for this investment anyway.
The only solution would be not a "stick" for the landlord but an extra "carrot" for the tenants. Maybe a form they can fill in "hey my landlord has solar panels and I want to profit too" and get some money back at the end of the year. Where could this money be extracted... not the tenants.. not the landlord.. tax office rebate, I think (it's their fault/problem that the current system is unfair towards the renters).
This would give a small additional incentive for the renters to prod their landlord to install solar panels.
It's not a large sum of money unless the renters live in a draughty monastery, so the tax office doesn't need a large extra control/enforcement staff to verify that the renters really have a landlord with solar panels.
(1) most importantly, fossil fuels being cheap is a temporary thing. At some point Germany (and the rest of the world) will no longer have access to cheap fossil fuels. Replacing them is a multi-decade project, and private industry is very bad at looking at far ahead so the government has to put different incentives in place.
It was a bit difficult to read, but the paradox sounds like those "Endverbraucher in Haushalten" who don't have solar panels, are basically forced to subsidize the difference between Börsenstrompreis and Ökostrompreis, and (brilliant use of mass psychology), this subsidy then goes to their own neighbours if they have a solar panel on the roof. So, if you don't invest € 980 in ( electricity + renewable infrastructure investment ) per year, your neighbours will be sure to profit instead of you.
It's fucking brilliant. Who came up with this idea? Joschka Fischer's Green Party? What a clever use of (some) people's "keeping up with the Joneses" wish, the need for renewable power infrastructure, the need to reduce carbon footprint, the political need to invest before you can reap the profits (big problem, see http://www.theoildrum.com/node/6647 (Jeff Vail - The Renewables Gap)).
IANAEconomist, but unless I have read the article wrong, I don't see what the problem is. Brilliant government strategy.
The liberal gentry and their pressure groups are going to permit the land use, water use, emissions, power generation, development and everything else to really recover.
Not.
They don't want it. Move in with your parents. Downsize yourself. Walk or stay home. That is the intended outcome.
Our parental overlords and their pressure groups and lizard people are going to permit our cookie jar to magically refill itself.
Not. They don't want it. They say that since we ate all the cookies, there are no more cookies. LIES! It's all their fault! You know who I mean.. them! The only reason for the lack of cookies is that they prevent the magical refilling process.
In other words: you're ascribing intent to what is a natural process of reacting to diminishing resources and societal collapse. Because, if it's somebody's fault, then at least in theory (after that somebody has been scapegoated) it can be corrected.
But people who try to live in reality see that people (e.g. their parents) grow older and feeble and will at one point die, and so it is with larger sociological constructs like corporations and societies and cultures. Like the apoptosis shortening your telomeres with every division, there are inevitable problems for our societies that cannot be solved with the political tools in place within our societies: "predicaments". So, they will fail to respond to certain classes of problems that are easy to see for outsiders but impossible / taboo to discuss within the organization: think "anathema".
Conserving energy, doing with less, adapting your consumption pattern to the production levels, is anathema in the USA, I think (I could be wrong because I've never visited the USA and never will). It is only this which makes an energy crisis into a deadly societal problem; other cultures just grin and bear it, put their pants belts a few teeth smaller, move in with their parents, plant expensive vegetables themselves, hope their children (if they can afford children) will have it a little better.
As long as there's a state of law and a sense of solidarity, many things are tolerable. The USSR collapsed and most people survived although it must have been a horrible time (read Dmitry Orlov or Jared Diamond, or "The Long Descent" by John Michael Greer, if you dare).
That was a fascinating read (some statistics required). Is the butchers vs neurosurgeons example a commonly used model? It reminds me of an old joke I vaguely remember from when the EU was smaller:
The Europe we want is where the cooks are French, the police are British, the mechanics are German, the lovers are Italian, and the bankers are Swiss.
The Europe we have is where the cooks are British, the police are German, the mechanics are French, the lovers are Swiss, and the bankers are Italian (well the latter is true currently).
The electromagnet of an MRI (or NMR machine as they were politically-incorrectly called) has a truly humongous field strength (order of 1 Tesla) and it's wound from Niobium-Tin alloy which is superconducting if you put it in a liquid Helium cooled NMR machine. So, you charge it up to the field strength it can bear without quenching, and then you just make sure to regularly top up the liquid Nitrogen (77 Kelvin = -195C) in the large Dewar barrel that surrounds the small Dewar barrel with liquid Helium (4 K).
It's a cool machine to work with;-)
In order for it to scan and flip the Hydrogen spins in the patient or sample tube you need variations in the electromagnetic field surrounding the probe, but they just do that with radio waves coming in from the sides. You can also do more complicated stuff with magnetic field gradients but I think the gradients are really really small perturbations of the main field strength (in the order of ppm).
tl;dr: the electromagnet of an MRI / NMR is never turned off; that's a minor industrial accident called a "quench" when the Helium and then the Nitrogen boils off and the personnel rapidly leaves the room. I've heard firsthand that it gives a very unpleasant feeling that is difficult to describe.
what exactly is this love affair with HSR?
in the 21st century we have air travel for long distance travel.
Sorry.. are you serious? I think you misspelled "20th century", or else you've never heard of Peak Oil.
I believe zeppelins are only a viable option in some special cases, and cannot replace kerosine-fueled passenger jets.
Slashdot Mirror
I fail to see how the export profit of of selling novelty horses that have mutated to grow horns on their heads would off-set the loss in GDP of not being able to live near those horses and rainbows..
I fear you are overlooking a very serious problem for the world elite: where are you going to find the nori for your sushi that *doesn't* glow-in-the-dark?
If you're making a funny joke (
How about they ask the Americans for help? We have had a lot of experience with nukes, (...)
), then you are a really sick bastard.
They *have* to pour more money in and clean it up. Japan is a very densely populated country. They can't all move out to "Japan 2.0" nextdoor, you know. If half of Honshu becomes uninhabitable for 300 years, where are they all going to live then?? Hokkaido?
I'm sure people would pay good money for Weka, except they don't have to because it's licensed under the GPL.
Maybe because an analog computer is usually not a general purpose computer (except maybe for the Difference Engine, but in the picture on the Wikipedia page even that looks quite inventive to me).
Good point about not mounting the USB stick but using dd. Just take the length of the message then, dd the length to the first 3 bytes of the stick, followed by the message. Then it doesn't need to be mounted (can't even :-)
Maybe it is possible to create errors in the USB stick hardware though..
The laptop(s) don't have a graphical desktop; only minimal installation, + program to decrypt the message, + program to handle the USB stick insert/read/write/withdraw. The only actions with the laptop are: USB stick in, USB stick out after a minute. What you say with "autolaunch" is an insane idea, I haven't used Gnome in a long time but I can't imagine that Nautilus does this by default though.
The decryption laptop needs to be highly secure: stored in a safe, not connected to anything, no WiFi, only USB stick work. Because it has to be re-usable: it is the only thing that contains the private key (ok maybe print out the private key in the old-fashioned Commodore 64 "short hex lines with checksum" way and put it in a safe in another building and burn the printer).
When the message has been decrypted, and the decrypted message is written on the USB stick, you can read it on a computer with lesser security (is there a way to write-protect USB sticks physically, like the old-fashioned floppies?). This second computer just has to be mounted freshly from live CD and not connected to the network either. Even if the message triggers something bad, the state of the computer is not important: its function is to convey the message to Bob. (of course as you say e.g. xpdf or okular can be subverted to change the content of a particular decrypted message). Multiple redundancy here as well, then. Any PDF reader that gives a different message from the other ones is very very interesting for Bob, who knows not only what Alice probably wrote, but also what the PDF reader subverter has substituted.
Since it seems to me that multiple redundancy would work well, and would yield both the original message and the subverted one for comparison, I conclude that this Ken Thompson attack is unlikely to be performed in practice, because it would yield too much information about what the attacker wants you to read in case of a special trigger message. (i.e. okular has been subverted but xpdf hasn't; and only if the message was about Barney the Dinosaur. Let's see who committed the change to okular that caused this.)
It's fun to think about these things for a one-off, but I'd hate to stake my career on this kind of stuff.. I hope universities have classes for computer security protocols.
In my career, I've just had lectures from various people about how they did things, and one thing I remember is that most serious sysadmins have spent years deeply thinking about how they could secure their bank/pension fund/public works in the best way.
But don't forget that for the recent scandals, there is probably no technical solution. Slashdotters are techies so they want to find technical solutions to problems. But in some cases, the only thing you can and must do is VOTE when the time comes, and remember on that day how you felt and what you thought today or in the last few weeks. Don't get distracted in the meantime... good luck!
I thought there was recent research about the Ken Thompson hack, I haven't read it tyough.. something called double compilation iirc.. it was on the LWN site.
Maybe you can use multiple redundancy like they do in mission critical environments: copy the message to three different USB sticks, put one in one laptop with FreeBSD and the program written in FORTRAN compiled with gcc, one laptop with new Ubuntu Linux and the program written in C compiled with clang, one laptop with the dustiest Debian that still works on it and the program written in Java, etc; an odd number of laptops. And if a particular message differs in its decrypted result, you know that at least one of the laptops has screwed up or been subverted, *and you can compare the decrypted messages* (should give you interesting information).
With respect to back doors etc: the nature of the possible corruption from malfeasance is limited by the (narrow) nature of the result produced: a file on the USB stick (ok, for the next post by kiwikiwi, just dd the USB stick and put the length of the data in the first 3 bytes)
Unless there really exists a "halt and catch fire" opcode, the nature of the damage is limited to writing different bytes to the USB stick in response to a message that triggers the attacker's hidden program on the laptop, i.e. a decrypted message that doesn't say what Alice wanted to say to Bob but what the infiltrator who had subverted the gcc compiler wanted to say in response to that particular encrypted message (what's the letter for this ? I never got further than A, B and Eve).
The nature of the possible damage is limited, because the function of the laptop in the organisation is such that you only want to let it write to the USB stick. If it says "aww please, connect me to the internet for updates", burn it.
I really don't see the problem.. either it's an isolated laptop locked up in a safe (I believe certification authorities use this set-up) where the people authorised to use it use USB sticks to transfer messages/certificates to/from the isolated laptop. I don't see how this can go wrong. Viruses are only a problem on really braindead OSes like MS Windows; why on earth would you use an OS that tried to execute anything that arrives on a USB stick for Real Work(TM)? It's a bogeyman that just doesn't exist on most OSes; I'll eat my hat(*) if bog standard Linux or FreeBSD installations try to execute anything on a USB stick unless it's rebooted with that stick as boot medium
Or, you have a secured network, where every employee has two computers on the desk; one connected to the normal ethernet and one connected to the secure private *wired* ethernet network. The employees who have to sometimes work with sensitive data use only programs on the private network connected computer for this. Typing them in by hand, as you say. Anytime somebody reconnects a computer to the wrong colour network cable, somebody gets fired. In this case you wouldn't want the secure computers to have DVD drives or USB ports of course.
(*) Disclaimer: I don't really have a hat, and I'm (obviously?) not a real security professional. Any corrections welcome.
FTFY.
That's brilliant! All the three-letter-organisation has to do is, if an encrypted document is stolen, tell the anti-virus company to flag its MD5 sum as "dangerous virus to be deleted on the spot and e-mail the T.L.O. about it". Oh wait a minute ...
Here you go: it's a lot shorter, but it's still in German:
https://www.bsi.bund.de/DE/Presse/Pressemitteilungen/Presse2013/Windows_TPM_Pl_21082013.html
It's more nuanced: the Bundesamt für Sicherheit in der Informationstechnik (B.S.I.) says it *doesn't* warn agains Microsoft Windows 8, it only warns the (German) government not to use Microsoft Windows 8 in certain scenarios on computer hardware with TPM 2.0:
Then, they first say that you can go ahead and buy MS Windows 8 on a TPM computer, as long as you don't worry/care ("kümmern") about the security of that computer. (There must be use cases within national and other governments where it just doesn't matter so much that a computer is insecure).
In the next paragraph, If I read it correctly (German is not my first or second language), they warn against using MS Windows 8 on a TPM 2.0 computer in case where security is of value: for " die Bundesverwaltung und kritische Infrastrukturen", they warn for the dangers of D.O.S. attack and sabotage where both the hardware and software become unusable. You got to read it yourself if you don't like my crummy translation. Corrections welcome.
I interpret the end of the press message as: maybe one day there will be a TPM 3.0 spec with "(...) ein bewusstes Opt-In sowie die Möglichkeit eines späteren Opt-Outs (...)" and then the BSI would be happy again.
IOW this TPM 2.0 "default on at first boot" is not a problem as long as governments buy only computers with a trusted signed Linux kernel and system. Additional advantage is that it's cheaper.
I hadn't thought of that. That's a good point. But to forbid or reduce the landlord's profit would disincentivise(sp?) him/her to improve the house, and the end-user electricity prices aren't going down anymore. And the lower income brackets, who rent, have no money to spare for this investment anyway.
.. not the landlord .. tax office rebate, I think (it's their fault/problem that the current system is unfair towards the renters).
The only solution would be not a "stick" for the landlord but an extra "carrot" for the tenants. Maybe a form they can fill in "hey my landlord has solar panels and I want to profit too" and get some money back at the end of the year. Where could this money be extracted... not the tenants
This would give a small additional incentive for the renters to prod their landlord to install solar panels.
It's not a large sum of money unless the renters live in a draughty monastery, so the tax office doesn't need a large extra control/enforcement staff to verify that the renters really have a landlord with solar panels.
The German Army may have something to do with it: http://www.spiegel.de/international/germany/peak-oil-and-the-german-government-military-study-warns-of-a-potentially-drastic-oil-crisis-a-715138.html
Big Shitstorm.
A certain East-Japanese power company wants to talk with you. Are you interested in buying 300 tons of diluted corrosive fuel for very very cheap?
<small-print>Shipping to jez9999's door, handling and insurance to be paid by the buyer.</small-print>
It was a bit difficult to read, but the paradox sounds like those "Endverbraucher in Haushalten" who don't have solar panels, are basically forced to subsidize the difference between Börsenstrompreis and Ökostrompreis, and (brilliant use of mass psychology), this subsidy then goes to their own neighbours if they have a solar panel on the roof. So, if you don't invest € 980 in ( electricity + renewable infrastructure investment ) per year, your neighbours will be sure to profit instead of you.
It's fucking brilliant. Who came up with this idea? Joschka Fischer's Green Party? What a clever use of (some) people's "keeping up with the Joneses" wish, the need for renewable power infrastructure, the need to reduce carbon footprint, the political need to invest before you can reap the profits (big problem, see http://www.theoildrum.com/node/6647 (Jeff Vail - The Renewables Gap)).
IANAEconomist, but unless I have read the article wrong, I don't see what the problem is. Brilliant government strategy.
Our parental overlords and their pressure groups and lizard people are going to permit our cookie jar to magically refill itself.
Not.
They don't want it. They say that since we ate all the cookies, there are no more cookies. LIES! It's all their fault! You know who I mean.. them! The only reason for the lack of cookies is that they prevent the magical refilling process.
In other words: you're ascribing intent to what is a natural process of reacting to diminishing resources and societal collapse. Because, if it's somebody's fault, then at least in theory (after that somebody has been scapegoated) it can be corrected.
But people who try to live in reality see that people (e.g. their parents) grow older and feeble and will at one point die, and so it is with larger sociological constructs like corporations and societies and cultures. Like the apoptosis shortening your telomeres with every division, there are inevitable problems for our societies that cannot be solved with the political tools in place within our societies: "predicaments". So, they will fail to respond to certain classes of problems that are easy to see for outsiders but impossible / taboo to discuss within the organization: think "anathema".
Conserving energy, doing with less, adapting your consumption pattern to the production levels, is anathema in the USA, I think (I could be wrong because I've never visited the USA and never will). It is only this which makes an energy crisis into a deadly societal problem; other cultures just grin and bear it, put their pants belts a few teeth smaller, move in with their parents, plant expensive vegetables themselves, hope their children (if they can afford children) will have it a little better.
As long as there's a state of law and a sense of solidarity, many things are tolerable. The USSR collapsed and most people survived although it must have been a horrible time (read Dmitry Orlov or Jared Diamond, or "The Long Descent" by John Michael Greer, if you dare).
That was a fascinating read (some statistics required). Is the butchers vs neurosurgeons example a commonly used model? It reminds me of an old joke I vaguely remember from when the EU was smaller:
The Europe we want is where the cooks are French, the police are British, the mechanics are German, the lovers are Italian, and the bankers are Swiss.
The Europe we have is where the cooks are British, the police are German, the mechanics are French, the lovers are Swiss, and the bankers are Italian (well the latter is true currently).
The electromagnet of an MRI (or NMR machine as they were politically-incorrectly called) has a truly humongous field strength (order of 1 Tesla) and it's wound from Niobium-Tin alloy which is superconducting if you put it in a liquid Helium cooled NMR machine. So, you charge it up to the field strength it can bear without quenching, and then you just make sure to regularly top up the liquid Nitrogen (77 Kelvin = -195C) in the large Dewar barrel that surrounds the small Dewar barrel with liquid Helium (4 K).
;-)
It's a cool machine to work with
In order for it to scan and flip the Hydrogen spins in the patient or sample tube you need variations in the electromagnetic field surrounding the probe, but they just do that with radio waves coming in from the sides. You can also do more complicated stuff with magnetic field gradients but I think the gradients are really really small perturbations of the main field strength (in the order of ppm).
tl;dr: the electromagnet of an MRI / NMR is never turned off; that's a minor industrial accident called a "quench" when the Helium and then the Nitrogen boils off and the personnel rapidly leaves the room. I've heard firsthand that it gives a very unpleasant feeling that is difficult to describe.
Must... resist... substituting word in Electric Six song...
Whereas in the Netherlands the old bread with eggs and milk is called "flipping bitches" (wentelteefjes). No, I'm not joking or exaggerating.
And in Swedish it's called "fattig riddare" which means "poor knight" like in German as I learned today: http://science.slashdot.org/comments.pl?sid=4089849&cid=44566217. At least that word is a bit more understandable..
Here: E^2 = p^2 c^2 + m_0^2 c^4
So, when p (momentum) is zero, E^2 = m_0^2 c^4
=> E = +/- m_0 c^2
Linky: http://en.wikipedia.org/wiki/Energy%E2%80%93momentum_relation
Sorry.. are you serious? I think you misspelled "20th century", or else you've never heard of Peak Oil.
I believe zeppelins are only a viable option in some special cases, and cannot replace kerosine-fueled passenger jets.
Pfff.. wake me when those last 2 nibbles have been changed from 21 to 212131216f6e652121 ...