There's a very real danger now, as terrorists have-or-will-soon-get a nuclear bomb, and it's not a scientific exercise; it's meant for killing....
In case you are talking about Iran then it is rather obvious not even they would be insane enough to use one. They don't want the bomb in order to attack the US ( that would only get them blown off the face of the earth ), they want it in order to be able to continue running the state as a theocratic dictatorship without risking external intervention. There is little risk Iran will actually use a nuke against another country. There is however a huge risk that they will get even more defiant of human rights once they have one.
Seriously, I'm a fairly strong supporter of Israel, I think it is a damn shame they didn't bomb Iran's enrichment plant to bits before it was reinforced, and I would welcome any country putting an end to Iran's nuclear program, but not even I seriously believe they are building a nuke to give to terrorists. If you honestly believe in that garbage then you are pretty close in foolishness to the morons who think Iran just wants civilian nuclear power. Try to realise the world isn't black and white, that Iran is pushing for nukes doesn't change the fact that the Bush administration is a lying and corrupt group of criminals who should rather be imprisoned than allowed to run a country.
When somebody has to maintain the damn thing. Seriously, how do you expect that deploying more complicated software is likely to remove the requirement of highly trained staff? It appears to me that while this might let you get away with fewer low-paid and moderately skilled people, it is going to make highly qualified system administrators even more crucial than before. Heck, in many cases the deployment of more advanced software means you are going to need more staff to deal with the ever increasing amount of data you generate. So rather than having some people maintain a small set of web-pages, you suddenly need a bunch of people making sure the web2.0 monster interface/backend/database is working smoothly, is not vulnerable to attacks, and that it gracefully interoperates with the rest of your system. Care to guess which of the two will require more qualified, and hence more expensive, staff ?
You know, for a country which is located on geology that has been nicknamed "the circle of fire", exposed to pacific storms, and has nuclear reactors in the vicinity of major geological fault-lines , I really don't think that a little bit of lithium is going to pose challanges beyond the skill of their engineers. If they can build bridges, skyscrapers and power plants, that barely gets scratched from a 6 on the Richter scale, then securing a rechargeable tram-battery sounds relatively simple.
Well, if the limit is the electrode surface area, then why not make electrodes in elaborate thin lattices, like metal snowflakes, or concentric cylinders drilled with lasers, coated with the rechargable cell chemicals?
You also have to worry about the resistance in the electrolyte, and the contact between the electrodes and the chemicals. While I'm sure they do optimise the surface area, I'm not sure it is as simple as "larger = better". I imagine you have to start taking into consideration how rapidly various compounds diffuse through the different materials, how heat conductivity is affected, how this would affect the possible working conditions for the battery, will it have consequences for its lifetime etc... Very often the simple schematic description of how something works is not quite the whole story.
The Oh-My-God particle (a play on the nickname "God particle" for the Higgs boson) is the nickname given to a particle observed on the evening of October 15, 1991, over Dugway Proving Grounds, Utah, estimated to have an energy of approximately 3 × 10**20 electronvolts, equivalent to about 50 joules
50 joule proton... Almost makes you suspect the gods made a mistake with their pointer arithmetic. Either that or someone crossed the streams.
Benjamin Jacob Grimm says "Wear your lead lined skivvies if your going into space, kids"
Of course, at this energy the impact of the proton with the lead would result in a lot of neutrons being released, and lead doesn't stop those very well. Maybe if you made some sort of composite-sandwich with lead followed by neutron moderating material and a neutron absorber. Of course, then the neutron-activation of the absorber would cause gamma-ray emissions, so you'd need another layer of lead, possibly followed by another neutron absorber. So, well, you might need something like lead-carbon-cadmium-lead-carbon-cadmium-lead lined underwear. Dry cleaning only, keep out of reach of children.
Wasn't it just a short while ago that these same people tossed aside net-neutrality? Either this is a huge double standard, or the people in control really have no idea whatsoever how the Internet works.
No, this is different. Net neutrality is a matter as of weather you can prioritise traffic based on who pays most. I don't think anybody would actually mind if comcast simply gave bit-torrent and encrypted traffic lower priority, the problem is they are sending faked packages to kill the connection. To use a bad analogy, dropping net neutrality would be like the post office charging you extra for next-day delivery while simultaneously charging the recipient a fee for receiving mails. What they are doing with bit-torrent is more akin to forging your girlfriend's handwriting saying the long-distance relationship is over, in order to make you stop sending her letters.
There is a clear difference here. In one case they are offering a lower quality service in order to try to charge companies for bandwidth you have already paid for. In the other case they send you fraudulent information, while simultaneously denying it and claiming their service is "unlimited". You can debate weather the former is fair, while the latter is a deliberate fraud and probably criminal.
I believe the problem is only with writes, not reads. Which, with a windows machine means that as long as there is a hardware switch to disable writes, it is more secure as well as faster to boot off a flash drive.
It is actually not even that bad. The problem is clearing bits, not setting them, so the system can spare a small marker for every so many chunks of data and mark it as "bad" when it is unable to erase it again. Thus you don't get sudden failures of the entire drive, rather you will get a reduced file-system size as the driver moves data to a still functional section ( and presumably warns you that the drive may need replacing ), which is a whole lot better than losing important data because the drive failed. Basically, with a good flash drive and a somewhat intelligent file system you could have the OS detect a drive that is about to go bad, warn you about it, and take measures to avoid data loss. For a HD you are more likely to have the entire drive just fail on you. Of course, you should ideally have a bunch of backups of your personal data in case of a fire or something anyway ( I'm not really the one to talk here. I'm going to make them next week, when I have time... just like last week... siiiigh ).
He then states that since electrons are thermalizing in the outer edges for >999/1000 of the time, they will fuse before core collisions maxwellianize them.
This is obviously nonsense. A single of-centre collision in the core is enough to give the ions involved dramatically different energies ( and keep in mind, you will have D-D and T-T side collisions as well , or B-B and p-p in the case of p-B fusion ), and they will thus obviously end up at different potential heights. Are you suggesting they would then "thermalize" so that they all end up on the same potential height? That would be prohibited per the laws of thermodynamics, unless you are feeding quite a bit of energy into the plasma ( much more so than the fusion power you could hop to get out of it in fact ). You can't restore a non-maxwellian velocity distribution through a spontaneous process, so I call bullshit here.
We won't have commercial fusion reactors in time for Oil if current trends continue. In a very best case scenario we have one single prototype reactor i 30 years, more likely we are talking 50 years before you see the first commercialised designs, if at all. Oil is expected to peak 2030. Basically, Fusion won't be replacing Oil any time soon.
When it comes to tritium, you could generate the small startup amount using a fission reactor. Once you have a small quantity of tritium the reactor could breed the rest on its own. It is unlikely we will get rid of all fission reactors before a large fleet of fusion reactors are deployed, so I doubt that will be much of a concern.
As for plutonium production, you could theoretically use a fusion reactor to breed plutonium, but why bother? If you have enough Uranium to breed the Plutonium from, then it would be many times easier to just build a traditional fission reactor. The US pulled it off in the 40ies, pretty much any industrialised country could do it. The real obstacle to countries getting nuclear weapons is international politics and a lack of will, not technology. It wouldn't be possible to perform the necessary modifications on a fusion reactor without it being detected by inspectors, so you wouldn't win much in terms of keeping the program secret. So well, I guess you could theoretically use a fusion reactor to make bombs, but I really don't see why anybody would do it that way.
JET achieved break even? I thought the closest it came under operating conditions was Q=0.7 Anything else was result extrapolation?
Sorry, my bad. I was confusing it with JT-60 which achieved D-D parameters corresponding to Q=1.25 had D-T fuel been used ( Tritium is radioactive and hence most devices use D-D for testing as the cost of tritium handling facilities can be quite large ).
ITER is going to have Q=10 when they haven't even got Q=1, an order of magnitude improvement.
Pretty much. The increase is mainly going to come from using a stronger magnetic field ( generated with superconducting magnets ) to achieve a better confinement time and higher number density. Data from JET has also helped pick a plasma shape which will be more optimal than the JET one.
The one thing that signals to me that ITER is flawed is that they are working on sub-systems without having proved the main idea. Wasting money on engineering when research is still not finished. Basically, they got so much money they had to find ways to spend it.
I don't quite get what you mean with doing engineering before research. In any complex device like this you will necessarily have to do the physics and engineering research in parallel. Otherwise you have a chicken and egg problem. I.e, you can't do the engineering without determining the physics, but you can't determine the physics without the engineering required to set up the experiment. This is what the ITER project seeks to deal with. It is intended as an experimental device which will provide sufficient information for the engineers and physicists to come up with a prototype for an actual power plant.
Your comment that restoring the non-maxwellian velocity distribution will require energy is oversimplified. You only need to maintain the non-maxwellian distribution long enough for the ions to fuse before they maxwellianize. Thermalization in the outer edge dominates the coulomb interactions from the core more than the collisions dominate the fusion rates. Those are the conditions that allow fusion to occur faster than maxwellianization. No magic, no violation of physics, just a beneficial design that Rider and Nevins both overlooked in their assumptions.
So Bussard claimed, but it is clearly nonsense. Where the collisions occur is irrelevant because you need collisions for fusion, and it is the collisions that screw up your mono-energetic energy distribution. You can't have collisions that cause fusion without having collisions that scatter the ions. The bit about the ions thermalising at the edge is also irrelevant since you need high-energy collisions in the core for fusion, and thus you get scattering at the same energies as well, thus distributing the ion energies across the entire spectrum.
The error in Bussard's claim was the assumption that the ions, after having been scattered in the central region, all reach virtually the same potential height. This is clearly not possible as it would imply you didn't have collisions in the central region, which in turns mean you don't have any fusion. In reality, fusion can only occur through high energy ion-ion collisions, and those are the very same collisions that will screw up your non-maxwellian velocity distribution. This would inevitably result in ions reaching dramatically different potential energies in the potential well, in contrast to Bussard's claim that they will thermalise to the same low energy. Thermalisation alone can NEVER take you from a maxwellian to a non-maxwellian energy distribution. It doesn't matter how you shape your potential well. It follows directly from statistical mechanics.
In fact, following Bussard's criticism, Rider actually went further and showed that NO fusion device could ever produce excess power if it was to be operated in a non-maxwellian energy distribution. The abstract is here: http://adsabs.harvard.edu/abs/1995PhDT........45R
I know this is ATI's problem but the Radeon 9200 has no support
I suppose there could be some minor difference between the version that causes yours to break, but my Radeon 9200 SE works just fine. After tweaking the xorg.conf settings I even got the open source ATI driver in xorg to play nice with compositing. Mind you, I rarely use it for anything really fancy, so I guess there could be issues I'm not aware off, and as always, that it works for me doesn't preclude it from being absolutely broken for you. Of course, in any case the problem is with ATI and not the DRI developers.
Anyway, this is about as big a hint as companies could get that: There's people who will work for free if you just let them do so!. Seriously, cut the crap already, you're not going to manage going toe to toe with Intel by keeping the "intellectual property" in your crappy wireless drivers secret. In case you are obliged by some NDA to not give them the specs, well then GOOD FUCKING JOB. You've managed to put yourself in a situation where you have to turn down people willing to work for free. I'm sure this helps you improve your efficiency and that your stock holders are overjoyed about it. Really , good job. Maybe for your next product line you could start to require activation codes and on-line registration. You know, just to create even more goodwill amongst your consumers...
Break even is seen as the holly grail with each method but without a self sustained reaction it's a very big expensive money pit that produces no power.
Not true. My above post highlighted problems with using high Z number ions because the large quantity of electrons, and relatively low fusion energy gain, makes it difficult to overcome the energy losses. For D-T fusion however ( and possibly D-D fusion ) , the fusion energy is both every high, and can occur at ( relatively speaking ) lower temperatures. As a consequence X-ray losses becomes minor compared to the fusion power provided you achieve a high enough temperature and number density. JET in England has already achieved break-even conditions, and ITER is expected to produce 10 times the energy you put into it. The folowup prototype plant after ITER would produce 25 times the input energy, producing several gigawatts of electricity.
So a government sanctioned monopoly ( or at least a monopoly the government doesn't hive a shit about trying to break up ) can be allowed to control communications, while simultaneously being obliged to provide information to the government under "National Security" concerns? IANAL but surely the way things works ( or at least were intended to work ) in the US is that the courts are to uphold the rights of the people even when a violation of those rights is not a violation according to the letter of the constitution, provided it goes against its spirit? I can see where this is going, if the government fails to uphold your rights, you can take their flesh, but not as much as a drop of blood.
Do you REALLY want a situation where the government isn't allowed to limit your freedom of speech, but it is perfectly acceptable to sit idle by and watch a big company in a monopoly position do it instead?
Unfortunately not. While oil will run out within decades, there is still plenty of coal and gas around. Quite enough of it to cause incalculable damage to the world if we don't stop using it. Fusion will probably not get popular until it can demonstrate lower prices than fission.
High temperatures is not the problem, D-T fusion only requires some 16keV, and this is easily achievable using rather cheap voltage source. However, to get more energy out than you get in, you must ensure that this energy stays in the plasma and causes fusion, rather than just radiating right out of it again. In practice this means you need a high density and large confinement time ( basically a measure of how rapidly the plasma loses energy ).
Now, the issue with fusion using fuels with higher atomic number than hydrogen is that the plasma will contain much more electrons, and this dramatically increases the amount of energy lost as bremsstrahlung when the electrons collide with the nuclei (the increased mass of the nuclei also plays a part ). Direct conversion of X-rays could theoretically help alleviate this as it would allow you to feed the lost energy back into the plasma, problem is, photo-voltaics have nowhere close to 100% efficiency.
Aneutronic fusion has advantages. You don't have to worry about neutron damage to the reactor vessel. However, when you look a bit closer at it, this isn't such a large advantage after all, because the neutrons are actually quite useful in that they deposit the energy over a quite large volume when they are being absorbed, reducing the stress caused by heating in the device. If it wasn't for the neutrons you would see most of the heat deposited in a comparably thin layer of the plasma-facing compounds. The counter for this is that aneutronic fusion releases the energy as charged particles, potentially allowing for directly converting the energy into electricity.
Basically, what this whole thing boils down to, is if you are able to achieve sufficiently good direct-conversion efficiency to counteract the increased X-ray losses due to the higher atomic numbers associated with aneutronic fusion. This is why you often see claims of breakthroughs in aneutronic fusion together with claims of either a non-maxwellian velocity distribution or some other remarkable way to reduce X-ray losses. A plasma with a maxwellian velocity distribution cannot sustain aneutronic fusion without being either very large and dense (to re-capture the X-rays) or by somehow capturing the lost X-rays after they leave the plasma and feeding the energy back into it.
For a non-maxwellian velocity distribution your problem is that even at optimal energies a collision is much more likely to scatter the ions than it is to cause fusion, and restoring the non-maxwellian velocity distribution will require energy (no, you don't get to violate the second law of thermodynamics I'm afraid ). For capturing X-rays your problem is to achieve a good enough conversion efficiency to make up for the dramatically increased X-ray losses.
With the exception of a few unconfirmed claims, nobody has been able to resolve the above problems (thou Bussard was quite vocal about his polywell device ) and this is pretty much why modern fusion power research uses D-T fusion. It gives the highest amount of energy for the lowest temperature and X-ray losses, at a maxwellian velocity distribution.
I'd like to suggest a colour space which treats every pixel as a small black-body, storing every colour as a long double precision floating point temperature value. It has probably already been done, and it is probably completely useless, but at least then I can troll the CMYK people by complaining that their colour-space doesn't properly support cosmic background radiation.
Okay, but that still doesn't complete the equation, how are we going to build and maintain these plants in the future if we have a major energy problem already? Not to mention all those who will be against the technology because of the dangers.
Also, you have to produce aircraft that can use this technology, and the infastructure to maintain it(airports being fitting with tanks and delivery systems, lots of educated people to do all this)
Hydrogen is the biggest pipe-dream.
[J]
Nuclear is more than up to the task. NIMBY opposition will drop as soon as the energy prices start rising rapidly. Many countries in Europe are planning nuclear reactors already.
As for the air-planes. the nice thing with them is that they have fairly fixed routes so you don't have to change the entire fleet at once. You could start operating a few of them on the most busy routes, and then gradually expand the use of the technology. This is dramatically different from personal cars, where it would be hard to deploy hydrogen because of a chicken and egg problem with fuel-stations vs cars.
Thus I'd say Hydrogen probably isn't likely for personal cars. High capacity batteries for those. Once the gas price starts spiraling out of control due to dwindling Oil reserves and increased consumption they will become popular. Airplanes need something with better energy/weight ratio however, and hydrogen is quite ideal for that.
I'd give it about 15-20 years until opposition against nuclear essentially vanish in most countries. At that point the first reactors that are capable of destroying long-lived waste on a commercial scales are estimated ( the physics and engineering is already proven, know-how for commercialization is being developed as we speak ) so the nuclear waste problem will more or less disapear as the time the stuff has to be stored drops bellow 300 years.
How much energy does it take to produce the hydrogen?
Assuming you get an efficiency of 50% for your Airplane, and an electrolytic conversion efficiency of about 60%-70%, then simple arithmetic would dictate that you get at best 35% of the energy you put into it as motion. In reality you spend a lot of energy transporting and storing it, so perhaps 10%-15% is a more reasonable estimate ( and yes, I'm somewhat pulling these numbers out of my ass ).
HOWEVER, the thing to remember is that while hydrogen is not the most efficient energy carrier, it is VERY clean ( assuming of course you generate the energy in a sustainable and non-polluting manner ). You get no carbon emissions, no sulphates, no particulates, no photochemical smog, no cancer inducing benzene derivatives etc...
The trick is producing the vast quantity of energy needed. Fast Breeder Reactors or Nuclear Fusion are both very promising in this regard. You could also use coal plants with carbon-capture and storage technology, high-efficiency solar plants, or of-shore wind farms. With the exception of Nuclear, most of these options would be considerably more expensive than the present energy sources, but with Oil running low we don't really have much choice. Factoring the costs associated with global warming into it will also tilt the equation quite a bit. Personally I'd go for the nuclear option, but some mix of energy sources is probably inevitable.
The problem with you story is that your average "End LUser" is not going to be able to edit the xorg.conf using vi, and even if they could, probably wouldn't know to change "nvidia" to "ati". The CLI is a bit beyond what most people care to know.... Until Ubuntu or whatever distro user can do every single thing in the GUI that they can do through the CLI, Window will have an advantage. MS writes Windows with a GUI in mind from the ground up. Linux is designed to work with or without a GUI. On rare occasion, such as the one you listed here, there will be an absolute need to use the CLI in Linux. Some people just can't handle that.
Now what a remarkable and amazing coincidence that Gutsy has such a fall-back GUI for fixing broken X sessions. It is almost as if they are working to make it more accessible to non-technical users...
Some time ago I accidentally fried my motherboard, so, time to get a new computer. My dad's job was throwing out an "old" machine. The new machine was a bit worse than my original one. It didn't have DDR2 memory, it used a Radeon 9200 rather than my nVidia card, the CPU was an old Pentium 4 rather than my faster AMD chip, and the integrated soundcard I had never heard of.
Anyway, I connect my HD which had Ubuntu Edgy installed on it, boot up. X complains about the video card so I change "nvidia" to "ati" in xorg.conf, type: startx, and 2 minutes latter I am reading my mail in thunderbird.
But you know, I'm sure Vista would perfectly well manage me changing ALL hardware except the HD, running on a P4 with 384MB SDRAM, and be up and running without even a reboot. Oh, and does Aero support virtual desktops yet?
Seriously, given the price and system requirements, Vista is a joke.
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In case you are talking about Iran then it is rather obvious not even they would be insane enough to use one. They don't want the bomb in order to attack the US ( that would only get them blown off the face of the earth ), they want it in order to be able to continue running the state as a theocratic dictatorship without risking external intervention. There is little risk Iran will actually use a nuke against another country. There is however a huge risk that they will get even more defiant of human rights once they have one.
Seriously, I'm a fairly strong supporter of Israel, I think it is a damn shame they didn't bomb Iran's enrichment plant to bits before it was reinforced, and I would welcome any country putting an end to Iran's nuclear program, but not even I seriously believe they are building a nuke to give to terrorists. If you honestly believe in that garbage then you are pretty close in foolishness to the morons who think Iran just wants civilian nuclear power. Try to realise the world isn't black and white, that Iran is pushing for nukes doesn't change the fact that the Bush administration is a lying and corrupt group of criminals who should rather be imprisoned than allowed to run a country.
When somebody has to maintain the damn thing. Seriously, how do you expect that deploying more complicated software is likely to remove the requirement of highly trained staff? It appears to me that while this might let you get away with fewer low-paid and moderately skilled people, it is going to make highly qualified system administrators even more crucial than before. Heck, in many cases the deployment of more advanced software means you are going to need more staff to deal with the ever increasing amount of data you generate. So rather than having some people maintain a small set of web-pages, you suddenly need a bunch of people making sure the web2.0 monster interface/backend/database is working smoothly, is not vulnerable to attacks, and that it gracefully interoperates with the rest of your system. Care to guess which of the two will require more qualified, and hence more expensive, staff ?
You know, for a country which is located on geology that has been nicknamed "the circle of fire", exposed to pacific storms, and has nuclear reactors in the vicinity of major geological fault-lines , I really don't think that a little bit of lithium is going to pose challanges beyond the skill of their engineers. If they can build bridges, skyscrapers and power plants, that barely gets scratched from a 6 on the Richter scale, then securing a rechargeable tram-battery sounds relatively simple.
You also have to worry about the resistance in the electrolyte, and the contact between the electrodes and the chemicals. While I'm sure they do optimise the surface area, I'm not sure it is as simple as "larger = better". I imagine you have to start taking into consideration how rapidly various compounds diffuse through the different materials, how heat conductivity is affected, how this would affect the possible working conditions for the battery, will it have consequences for its lifetime etc... Very often the simple schematic description of how something works is not quite the whole story.
50 joule proton... Almost makes you suspect the gods made a mistake with their pointer arithmetic. Either that or someone crossed the streams.
Of course, at this energy the impact of the proton with the lead would result in a lot of neutrons being released, and lead doesn't stop those very well. Maybe if you made some sort of composite-sandwich with lead followed by neutron moderating material and a neutron absorber. Of course, then the neutron-activation of the absorber would cause gamma-ray emissions, so you'd need another layer of lead, possibly followed by another neutron absorber. So, well, you might need something like lead-carbon-cadmium-lead-carbon-cadmium-lead lined underwear. Dry cleaning only, keep out of reach of children.
No, this is different. Net neutrality is a matter as of weather you can prioritise traffic based on who pays most. I don't think anybody would actually mind if comcast simply gave bit-torrent and encrypted traffic lower priority, the problem is they are sending faked packages to kill the connection. To use a bad analogy, dropping net neutrality would be like the post office charging you extra for next-day delivery while simultaneously charging the recipient a fee for receiving mails. What they are doing with bit-torrent is more akin to forging your girlfriend's handwriting saying the long-distance relationship is over, in order to make you stop sending her letters.
There is a clear difference here. In one case they are offering a lower quality service in order to try to charge companies for bandwidth you have already paid for. In the other case they send you fraudulent information, while simultaneously denying it and claiming their service is "unlimited". You can debate weather the former is fair, while the latter is a deliberate fraud and probably criminal.
It is actually not even that bad. The problem is clearing bits, not setting them, so the system can spare a small marker for every so many chunks of data and mark it as "bad" when it is unable to erase it again. Thus you don't get sudden failures of the entire drive, rather you will get a reduced file-system size as the driver moves data to a still functional section ( and presumably warns you that the drive may need replacing ), which is a whole lot better than losing important data because the drive failed. Basically, with a good flash drive and a somewhat intelligent file system you could have the OS detect a drive that is about to go bad, warn you about it, and take measures to avoid data loss. For a HD you are more likely to have the entire drive just fail on you. Of course, you should ideally have a bunch of backups of your personal data in case of a fire or something anyway ( I'm not really the one to talk here. I'm going to make them next week, when I have time
This is obviously nonsense. A single of-centre collision in the core is enough to give the ions involved dramatically different energies ( and keep in mind, you will have D-D and T-T side collisions as well , or B-B and p-p in the case of p-B fusion ), and they will thus obviously end up at different potential heights. Are you suggesting they would then "thermalize" so that they all end up on the same potential height? That would be prohibited per the laws of thermodynamics, unless you are feeding quite a bit of energy into the plasma ( much more so than the fusion power you could hop to get out of it in fact ). You can't restore a non-maxwellian velocity distribution through a spontaneous process, so I call bullshit here.
We won't have commercial fusion reactors in time for Oil if current trends continue. In a very best case scenario we have one single prototype reactor i 30 years, more likely we are talking 50 years before you see the first commercialised designs, if at all. Oil is expected to peak 2030. Basically, Fusion won't be replacing Oil any time soon.
When it comes to tritium, you could generate the small startup amount using a fission reactor. Once you have a small quantity of tritium the reactor could breed the rest on its own. It is unlikely we will get rid of all fission reactors before a large fleet of fusion reactors are deployed, so I doubt that will be much of a concern.
As for plutonium production, you could theoretically use a fusion reactor to breed plutonium, but why bother? If you have enough Uranium to breed the Plutonium from, then it would be many times easier to just build a traditional fission reactor. The US pulled it off in the 40ies, pretty much any industrialised country could do it. The real obstacle to countries getting nuclear weapons is international politics and a lack of will, not technology. It wouldn't be possible to perform the necessary modifications on a fusion reactor without it being detected by inspectors, so you wouldn't win much in terms of keeping the program secret. So well, I guess you could theoretically use a fusion reactor to make bombs, but I really don't see why anybody would do it that way.
So Bussard claimed, but it is clearly nonsense. Where the collisions occur is irrelevant because you need collisions for fusion, and it is the collisions that screw up your mono-energetic energy distribution. You can't have collisions that cause fusion without having collisions that scatter the ions. The bit about the ions thermalising at the edge is also irrelevant since you need high-energy collisions in the core for fusion, and thus you get scattering at the same energies as well, thus distributing the ion energies across the entire spectrum.
The error in Bussard's claim was the assumption that the ions, after having been scattered in the central region, all reach virtually the same potential height. This is clearly not possible as it would imply you didn't have collisions in the central region, which in turns mean you don't have any fusion. In reality, fusion can only occur through high energy ion-ion collisions, and those are the very same collisions that will screw up your non-maxwellian velocity distribution. This would inevitably result in ions reaching dramatically different potential energies in the potential well, in contrast to Bussard's claim that they will thermalise to the same low energy. Thermalisation alone can NEVER take you from a maxwellian to a non-maxwellian energy distribution. It doesn't matter how you shape your potential well. It follows directly from statistical mechanics.
In fact, following Bussard's criticism, Rider actually went further and showed that NO fusion device could ever produce excess power if it was to be operated in a non-maxwellian energy distribution. The abstract is here: http://adsabs.harvard.edu/abs/1995PhDT........45R
You do realise that Adobe has software packaged in the Ubuntu repository?
I suppose there could be some minor difference between the version that causes yours to break, but my Radeon 9200 SE works just fine. After tweaking the xorg.conf settings I even got the open source ATI driver in xorg to play nice with compositing. Mind you, I rarely use it for anything really fancy, so I guess there could be issues I'm not aware off, and as always, that it works for me doesn't preclude it from being absolutely broken for you. Of course, in any case the problem is with ATI and not the DRI developers.
Anyway, this is about as big a hint as companies could get that: There's people who will work for free if you just let them do so!. Seriously, cut the crap already, you're not going to manage going toe to toe with Intel by keeping the "intellectual property" in your crappy wireless drivers secret. In case you are obliged by some NDA to not give them the specs, well then GOOD FUCKING JOB. You've managed to put yourself in a situation where you have to turn down people willing to work for free. I'm sure this helps you improve your efficiency and that your stock holders are overjoyed about it. Really , good job. Maybe for your next product line you could start to require activation codes and on-line registration. You know, just to create even more goodwill amongst your consumers...
Not true. My above post highlighted problems with using high Z number ions because the large quantity of electrons, and relatively low fusion energy gain, makes it difficult to overcome the energy losses. For D-T fusion however ( and possibly D-D fusion ) , the fusion energy is both every high, and can occur at ( relatively speaking ) lower temperatures. As a consequence X-ray losses becomes minor compared to the fusion power provided you achieve a high enough temperature and number density. JET in England has already achieved break-even conditions, and ITER is expected to produce 10 times the energy you put into it. The folowup prototype plant after ITER would produce 25 times the input energy, producing several gigawatts of electricity.
So a government sanctioned monopoly ( or at least a monopoly the government doesn't hive a shit about trying to break up ) can be allowed to control communications, while simultaneously being obliged to provide information to the government under "National Security" concerns? IANAL but surely the way things works ( or at least were intended to work ) in the US is that the courts are to uphold the rights of the people even when a violation of those rights is not a violation according to the letter of the constitution, provided it goes against its spirit? I can see where this is going, if the government fails to uphold your rights, you can take their flesh, but not as much as a drop of blood.
Do you REALLY want a situation where the government isn't allowed to limit your freedom of speech, but it is perfectly acceptable to sit idle by and watch a big company in a monopoly position do it instead?
High temperatures is not the problem, D-T fusion only requires some 16keV, and this is easily achievable using rather cheap voltage source. However, to get more energy out than you get in, you must ensure that this energy stays in the plasma and causes fusion, rather than just radiating right out of it again. In practice this means you need a high density and large confinement time ( basically a measure of how rapidly the plasma loses energy ).
Now, the issue with fusion using fuels with higher atomic number than hydrogen is that the plasma will contain much more electrons, and this dramatically increases the amount of energy lost as bremsstrahlung when the electrons collide with the nuclei (the increased mass of the nuclei also plays a part ). Direct conversion of X-rays could theoretically help alleviate this as it would allow you to feed the lost energy back into the plasma, problem is, photo-voltaics have nowhere close to 100% efficiency.
Aneutronic fusion has advantages. You don't have to worry about neutron damage to the reactor vessel. However, when you look a bit closer at it, this isn't such a large advantage after all, because the neutrons are actually quite useful in that they deposit the energy over a quite large volume when they are being absorbed, reducing the stress caused by heating in the device. If it wasn't for the neutrons you would see most of the heat deposited in a comparably thin layer of the plasma-facing compounds. The counter for this is that aneutronic fusion releases the energy as charged particles, potentially allowing for directly converting the energy into electricity.
Basically, what this whole thing boils down to, is if you are able to achieve sufficiently good direct-conversion efficiency to counteract the increased X-ray losses due to the higher atomic numbers associated with aneutronic fusion. This is why you often see claims of breakthroughs in aneutronic fusion together with claims of either a non-maxwellian velocity distribution or some other remarkable way to reduce X-ray losses. A plasma with a maxwellian velocity distribution cannot sustain aneutronic fusion without being either very large and dense (to re-capture the X-rays) or by somehow capturing the lost X-rays after they leave the plasma and feeding the energy back into it.
For a non-maxwellian velocity distribution your problem is that even at optimal energies a collision is much more likely to scatter the ions than it is to cause fusion, and restoring the non-maxwellian velocity distribution will require energy (no, you don't get to violate the second law of thermodynamics I'm afraid ). For capturing X-rays your problem is to achieve a good enough conversion efficiency to make up for the dramatically increased X-ray losses.
With the exception of a few unconfirmed claims, nobody has been able to resolve the above problems (thou Bussard was quite vocal about his polywell device ) and this is pretty much why modern fusion power research uses D-T fusion. It gives the highest amount of energy for the lowest temperature and X-ray losses, at a maxwellian velocity distribution.
No.
Yes.
There, I hope that cleared things up a bit.
I'd like to suggest a colour space which treats every pixel as a small black-body, storing every colour as a long double precision floating point temperature value. It has probably already been done, and it is probably completely useless, but at least then I can troll the CMYK people by complaining that their colour-space doesn't properly support cosmic background radiation.
... and as we all know Microsoft is the kind of company that would NEVER piss of their customers by forcing them to upgrade their systems...
Nuclear is more than up to the task. NIMBY opposition will drop as soon as the energy prices start rising rapidly. Many countries in Europe are planning nuclear reactors already.
As for the air-planes. the nice thing with them is that they have fairly fixed routes so you don't have to change the entire fleet at once. You could start operating a few of them on the most busy routes, and then gradually expand the use of the technology. This is dramatically different from personal cars, where it would be hard to deploy hydrogen because of a chicken and egg problem with fuel-stations vs cars.
Thus I'd say Hydrogen probably isn't likely for personal cars. High capacity batteries for those. Once the gas price starts spiraling out of control due to dwindling Oil reserves and increased consumption they will become popular. Airplanes need something with better energy/weight ratio however, and hydrogen is quite ideal for that.
I'd give it about 15-20 years until opposition against nuclear essentially vanish in most countries. At that point the first reactors that are capable of destroying long-lived waste on a commercial scales are estimated ( the physics and engineering is already proven, know-how for commercialization is being developed as we speak ) so the nuclear waste problem will more or less disapear as the time the stuff has to be stored drops bellow 300 years.
Assuming you get an efficiency of 50% for your Airplane, and an electrolytic conversion efficiency of about 60%-70%, then simple arithmetic would dictate that you get at best 35% of the energy you put into it as motion. In reality you spend a lot of energy transporting and storing it, so perhaps 10%-15% is a more reasonable estimate ( and yes, I'm somewhat pulling these numbers out of my ass ).
HOWEVER, the thing to remember is that while hydrogen is not the most efficient energy carrier, it is VERY clean ( assuming of course you generate the energy in a sustainable and non-polluting manner ). You get no carbon emissions, no sulphates, no particulates, no photochemical smog, no cancer inducing benzene derivatives etc...
The trick is producing the vast quantity of energy needed. Fast Breeder Reactors or Nuclear Fusion are both very promising in this regard. You could also use coal plants with carbon-capture and storage technology, high-efficiency solar plants, or of-shore wind farms. With the exception of Nuclear, most of these options would be considerably more expensive than the present energy sources, but with Oil running low we don't really have much choice. Factoring the costs associated with global warming into it will also tilt the equation quite a bit. Personally I'd go for the nuclear option, but some mix of energy sources is probably inevitable.
Now what a remarkable and amazing coincidence that Gutsy has such a fall-back GUI for fixing broken X sessions. It is almost as if they are working to make it more accessible to non-technical users...
Some time ago I accidentally fried my motherboard, so, time to get a new computer. My dad's job was throwing out an "old" machine. The new machine was a bit worse than my original one. It didn't have DDR2 memory, it used a Radeon 9200 rather than my nVidia card, the CPU was an old Pentium 4 rather than my faster AMD chip, and the integrated soundcard I had never heard of.
Anyway, I connect my HD which had Ubuntu Edgy installed on it, boot up. X complains about the video card so I change "nvidia" to "ati" in xorg.conf, type: startx, and 2 minutes latter I am reading my mail in thunderbird.
But you know, I'm sure Vista would perfectly well manage me changing ALL hardware except the HD, running on a P4 with 384MB SDRAM, and be up and running without even a reboot. Oh, and does Aero support virtual desktops yet?
Seriously, given the price and system requirements, Vista is a joke.