How do all of these storage solutions scale?
EG Pumped storage for all of Chicago would require putting an area comparable to Chicago's underwater (600 km^2).
Pumped storage has an capacity of a few Watts per m^2 depending on the depth change available (typically a few meters). Chicago uses energy at an average rate of 20 GW so you need an area on the order of 10^10 m^2 or a square area that is 100km on a side.
BTW In Illinois about half the power comes from nuclear, the other half from coal.
There is a very simple counter factual to this. CEO pay has grown 6 fold since 1990 (Forbes). The economy hasn't. Median salary hasn't. Have they somehow become six times rarer or six times more effective without the economy noticing? The market doesn't drive ceo salary. Productivity doesn't drive ceo salary.
Well, you're both wrong. You can't simply redefine the terms to win your argument and the term supercomputer doesn't necessarily refer to computer cores networked by a high speed interconnect. Come to think of it, the original post is absurd, because there is no way BOINC could run LINPACK which is the measure of the TOP500 rankings anyway. LINPACK stresses communication performance as well as scalar processor performance. BOINC would probably be slower than my desktop for that purpose.
Like a lot of these silly comparisons on slashdot ("My hammer is better than your screwdriver!") it comes down to using the right tool for the right job. If you're not in a hurry and your job is "a bag of jobs" type problem, use BOINC or some other distributed/cloud computing approach. If you're trying to solve some type of PDE use a purpose built system like Roadrunner. Using something like Roadrunner for the type of jobs that BOINC is good at is just a waste of resources - those networks aren't cheap.
Maybe for new construction. Half the cost of retrofitting solar cells on existing homes is installation. Even if they were free, it wouldn't be economical to install them. To both efficiency and cost play a role. If I don't need to cover my whole roof, installation is cheaper.
From Bussard's google talk, he estimated the COE to be in the range of 0.02 USD to 0.05 USD/kwhr. That implies a cost of at least $1/W for the plant. 1GW=1Billion USD. You can decide if that is a tiny fraction of ITER construction or not. Of course we're assuming that the first full scale polywell reactor will be built on time and on budget with no difficulties.
And of course, the fusion community has not invested everything in a single solution. Even researchers on ITER and other tokamaks have often been involved/invested in other designs in the past: mirrors, stellerators, pinches - an existence proof that they are able to recognize promising new concepts. Just because they don't recognize polywell as promising doesn't mean they are wrong.
One of hydrogen's many problems is that you can't bring enough along to get very far. Now if only there were something you could bind it to so that it could be packed far more densely . ..hmmm, I here the carbon and oxygen work pretty well.
power = energy/time
Tell the jet pilots their highly refined fuel is less powerful.
Diesel engines get better mileage because the diesel has to be burned at a higher temperature than gasoline engines -> higher Carnot efficiency.
That said, bio energy advocates should consider that photosynthesis is generally 1% efficient at making sugars from the sun, and that is BEFORE you dry it and convert it to your fuel stock of choice.
At small scales the Reynolds number ~ vL/nu gets smaller. So for a given velocity, smaller objects behave like they are in a more viscous medium. Flexible wings that "swim" through the air can be more efficient and more stable than fixed wings at such scales.
They use lasers and lcds. The lifetime should be quite long. No bulbs to replace.
They're even talking about fitting these things into smart phones eventually. With a market that size the cost should truly be under $300.
In my experience its less and less. It's better on international than domestic and better on non-US carriers. But its not something you can rely on even with a lot of advance planning with seatguru.com unless you're always flying business class or above.
I'd settle for a laptop that actually gets the battery life it claims and doesn't drop capacity by 50% after 1 yr of regular use.
I agree with your last point though with one modifier; that airlines actually have power available in most or preferable all coach seats, at least on all long haul flights.
I live in the US. I can get to google.cn and use it. Try searching "tianamen square" (note deliberate misspelling). 2nd hit is Wikipedia article on Tiananmen Square and the protests and massacre there. This is the same as the first hit searching from US google.com
I've heard this is the case for many other proscribed searches. Not to defend what google did, but it seems they did the minimum the law required them do to and the info is still there if you're a little creative.
Would it have made more sense to you if he had said that they thermal depolymerisation is an exothermic reaction? The turkey guts are basically burned with the oxygen from the air producing heat, water, C02, and some oil and gas. The turkey guts have energy in them, just as most organic materials do. A coal plant can power it's own lights with energy left over, and the thermal depolymerisation can too. But it only has a very little bit left over. It's really just an interesting way to accelerate the natural recycling process.
That prediction was based on a growing fusion budget. Back in the late 70s the budget was over 700 million US$/year and has decreased steadily to 280 million US$/year in 2002 dollars. That level is basically life support for the program. They killed the 2 million$/year design program for FIRE because they can't AFFORD to do FIRE, maintain the basic program and participate in ITER. The US and Soviet Union started the original ITER in the late 1980s, and now the US is participating at the level of China, and Russia has in kind contributions, but no cash. You want fusion in 30 years, you have to PAY for it.
The vacuum in space is much much better than the best laboratory plasmas and the surface of the moon is comparable to lab plasmas.( 1 particle per cubic cm for space, 10^6 to 10^5 for the the moon, and 10^5 to 10^4 for the lab) or in atmospheres ( 10^-20, 10^-13 to 10^-15, 10^-12 to 10^-15 ) source:http://hypertextbook.com/physics/matter/pre ssure/
The real problem is that you still need a plasma facing surface and to generate a magnetic field. All that mass is expensive to get to the moon, and the constraint on the physical size of the magnets (bigger is more expensive) and the need to protect them from the plasma would result in a very similar vessel being constructed on the moon. So there would be very little direct benefit. There is the remote possibility of using the exotic D-He3 fusion reaction - one that is much more difficult to create, but that is essentially neutron free. Since He3 is only found in any concentration in the surface of the moon where it is deposited by the solar wind.
Besides Java as a legacy, what about OpenOffice itself? Wasn't openoffice started after sun released the source of staroffice, and even provided some support?
Sun is on hard times. There have been a few rounds of layoffs in the last year. A friend of mine has been let go from SUN, though with very generous severence - something like getting all his remaining vacation, not having to report to work for his last month, and two months paid severence. Essentially about three months of paid vacation before unemployment kicks in. Another friend who consulted for SUN did not have her contract picked up again last year as well.
Take the probable reaction for a reactor:
D + T = He4 + n + some kinetic energy
where D and T are isotopes of H.
The mass deficit for this reaction is about 0.3 % of the mass of the reactants (D + T) and is a consequence of the reduced strong nuclear force needed to bind the He4 nucleus. It is reflected in the difference in mass of the 2 protons and three neutrons in the D and T nuclei and the 2 protrons and 2 neutrons in the He4 nuclei and and free neutron. The mass=energy, that reduced binding energy means the He4 nuclei + free neutron are actually less massive than the D and T. E=mc^2 is applied to the mass deficit to get the energy released per reaction, that is, the kinetic energy, which is about 17.6 Mev in this case or 2.8 x 10-12 Joules. For comparison, chemical reactions, like burning coal or natural gas, release a few ev/reaction, or about a million times less energy per molecule of fuel.
That's why fusion research is being pursued.
Disclaimer, IAAFR (I am a fusion researcher.)
Re:In the land of empty tanks
on
Out of Gas
·
· Score: 1
Don't forget that grain takes a significant amount of oil in the form of fertilizer. I don't know how that compares to beef in a kC/$US measure, but it's not insignificant.
Well, it may seem mostly barren, but
areas of the antarctic ice can be as thick as 3000 meters and account for the bulk of the worlds fresh water. It accounts for about 70 percent of the earth's fresh water and by volume is about 2 percent of the total water on earth. So 30 feet seems quite reasonable. See The Physics HyperTextbook
On the expansion of substances, true, liquids and solids expand little compared with gases, but
the rate of expansion with temperature for solids that make up the earth's crust are about two orders of magnitude less than that of water. And given the average ocean depth of about 3800 meters, only a small amount of expansion is necessary to raise the sea levels by a noticable amount. I confess that it never occurred to me to take into
account the affect of the expansion of the earth's crust, but since below 100 ft or so its pretty much determined by the heating from the core, and it's rate of thermal expansion it negligible compared to water it wouldn't seem to be a significant factor. (A correction, the link in my OP was posted with a space, so I give it again here. Also, I referred to the bulk modulus and I should have said the coefficient of thermal expansion, which is related to the dependence of the modulus on temperature.)
I agree that there are many factors to consider in global warming modelling. You'd be surprised at how many factors are considered. (IANACM)
Alright, I can buy the alien death ray theory, but I can't let the bad science go by w/o a comment. The 10% of the ice above the water is there because ice is less dense than water by that amount - that's why it floats! The melting of floating ice doesn't raise water levels. As the poster said, it is the ice that sits on land that contributes to water levels as it melts (ie the bulk of antarctic ice).
That all being said, none of that is the real issue, unless the whole of antarctic ice slides into the ocean. The surprising effect is the finite bulk modulus of water. That is, as it gets warmer, it expands. For example, an increase in ocean temperature of 1 degree K, will raise the level 0.6 m (see http://www.mas.ncl.ac.uk/~sbrooks/book/nish.mit.ed u/2006/Textbook/Nodes/chap01/node12.html for a brief discussion.)
Re:I'll be impressed when they can print me a whol
on
Print Yourself a Femur
·
· Score: 1
Me too, I could use a pair of hips. Unfortunately, with joint replacements, the bone is only part of the story. You need cartelidge and preferable some good ligaments as well - stuff that goes bye-bye after artificial joint replacement.
Serious scaling issues limit current fusion reactor designs to ~> 1 GW, not very portable.
The most feasible fuel right now does use heavy hydrogen (deuterium) for half it's fuel, the other half is tritium (an even heavier hydrogen) that must be produced on site from lithium.
Fusion reactors do not need cooling in the sense that fission reactors do, however water could be part of a steam cycle for production of electricity.
Deuterium is present at around 140ppm (parts per million), as so heavy water is not a practical fluid for steam cycles.
Slashdot Mirror
coincidence?
How do all of these storage solutions scale? EG Pumped storage for all of Chicago would require putting an area comparable to Chicago's underwater (600 km^2). Pumped storage has an capacity of a few Watts per m^2 depending on the depth change available (typically a few meters). Chicago uses energy at an average rate of 20 GW so you need an area on the order of 10^10 m^2 or a square area that is 100km on a side. BTW In Illinois about half the power comes from nuclear, the other half from coal.
There aren't enough roofs in Chicago.
Clearly not getting a masters in statistics though. Selection bias anyone?
There is a very simple counter factual to this. CEO pay has grown 6 fold since 1990 (Forbes). The economy hasn't. Median salary hasn't. Have they somehow become six times rarer or six times more effective without the economy noticing? The market doesn't drive ceo salary. Productivity doesn't drive ceo salary.
Well, you're both wrong. You can't simply redefine the terms to win your argument and the term supercomputer doesn't necessarily refer to computer cores networked by a high speed interconnect. Come to think of it, the original post is absurd, because there is no way BOINC could run LINPACK which is the measure of the TOP500 rankings anyway. LINPACK stresses communication performance as well as scalar processor performance. BOINC would probably be slower than my desktop for that purpose. Like a lot of these silly comparisons on slashdot ("My hammer is better than your screwdriver!") it comes down to using the right tool for the right job. If you're not in a hurry and your job is "a bag of jobs" type problem, use BOINC or some other distributed/cloud computing approach. If you're trying to solve some type of PDE use a purpose built system like Roadrunner. Using something like Roadrunner for the type of jobs that BOINC is good at is just a waste of resources - those networks aren't cheap.
Maybe for new construction. Half the cost of retrofitting solar cells on existing homes is installation. Even if they were free, it wouldn't be economical to install them. To both efficiency and cost play a role. If I don't need to cover my whole roof, installation is cheaper.
From Bussard's google talk, he estimated the COE to be in the range of 0.02 USD to 0.05 USD/kwhr. That implies a cost of at least $1/W for the plant. 1GW=1Billion USD. You can decide if that is a tiny fraction of ITER construction or not. Of course we're assuming that the first full scale polywell reactor will be built on time and on budget with no difficulties. And of course, the fusion community has not invested everything in a single solution. Even researchers on ITER and other tokamaks have often been involved/invested in other designs in the past: mirrors, stellerators, pinches - an existence proof that they are able to recognize promising new concepts. Just because they don't recognize polywell as promising doesn't mean they are wrong.
One of hydrogen's many problems is that you can't bring enough along to get very far. Now if only there were something you could bind it to so that it could be packed far more densely . . .hmmm, I here the carbon and oxygen work pretty well.
power = energy/time Tell the jet pilots their highly refined fuel is less powerful. Diesel engines get better mileage because the diesel has to be burned at a higher temperature than gasoline engines -> higher Carnot efficiency. That said, bio energy advocates should consider that photosynthesis is generally 1% efficient at making sugars from the sun, and that is BEFORE you dry it and convert it to your fuel stock of choice.
At small scales the Reynolds number ~ vL/nu gets smaller. So for a given velocity, smaller objects behave like they are in a more viscous medium. Flexible wings that "swim" through the air can be more efficient and more stable than fixed wings at such scales.
They use lasers and lcds. The lifetime should be quite long. No bulbs to replace. They're even talking about fitting these things into smart phones eventually. With a market that size the cost should truly be under $300.
In my experience its less and less. It's better on international than domestic and better on non-US carriers. But its not something you can rely on even with a lot of advance planning with seatguru.com unless you're always flying business class or above. I'd settle for a laptop that actually gets the battery life it claims and doesn't drop capacity by 50% after 1 yr of regular use. I agree with your last point though with one modifier; that airlines actually have power available in most or preferable all coach seats, at least on all long haul flights.
I live in the US. I can get to google.cn and use it. Try searching "tianamen square" (note deliberate misspelling). 2nd hit is Wikipedia article on Tiananmen Square and the protests and massacre there. This is the same as the first hit searching from US google.com I've heard this is the case for many other proscribed searches. Not to defend what google did, but it seems they did the minimum the law required them do to and the info is still there if you're a little creative.
Would it have made more sense to you if he had said that they thermal depolymerisation is an exothermic reaction? The turkey guts are basically burned with the oxygen from the air producing heat, water, C02, and some oil and gas. The turkey guts have energy in them, just as most organic materials do. A coal plant can power it's own lights with energy left over, and the thermal depolymerisation can too. But it only has a very little bit left over. It's really just an interesting way to accelerate the natural recycling process.
That prediction was based on a growing fusion budget. Back in the late 70s the budget was over 700 million US$/year and has decreased steadily to 280 million US$/year in 2002 dollars. That level is basically life support for the program. They killed the 2 million$/year design program for FIRE because they can't AFFORD to do FIRE, maintain the basic program and participate in ITER. The US and Soviet Union started the original ITER in the late 1980s, and now the US is participating at the level of China, and Russia has in kind contributions, but no cash. You want fusion in 30 years, you have to PAY for it.
The vacuum in space is much much better than the best laboratory plasmas and the surface of the moon is comparable to lab plasmas.( 1 particle per cubic cm for space, 10^6 to 10^5 for the the moon, and 10^5 to 10^4 for the lab) or in atmospheres ( 10^-20, 10^-13 to 10^-15, 10^-12 to 10^-15 ) source:http://hypertextbook.com/physics/matter/pre ssure/
The real problem is that you still need a plasma facing surface and to generate a magnetic field. All that mass is expensive to get to the moon, and the constraint on the physical size of the magnets (bigger is more expensive) and the need to protect them from the plasma would result in a very similar vessel being constructed on the moon. So there would be very little direct benefit. There is the remote possibility of using the exotic D-He3 fusion reaction - one that is much more difficult to create, but that is essentially neutron free. Since He3 is only found in any concentration in the surface of the moon where it is deposited by the solar wind.
Besides Java as a legacy, what about OpenOffice itself? Wasn't openoffice started after sun released the source of staroffice, and even provided some support? Sun is on hard times. There have been a few rounds of layoffs in the last year. A friend of mine has been let go from SUN, though with very generous severence - something like getting all his remaining vacation, not having to report to work for his last month, and two months paid severence. Essentially about three months of paid vacation before unemployment kicks in. Another friend who consulted for SUN did not have her contract picked up again last year as well.
Take the probable reaction for a reactor: D + T = He4 + n + some kinetic energy where D and T are isotopes of H. The mass deficit for this reaction is about 0.3 % of the mass of the reactants (D + T) and is a consequence of the reduced strong nuclear force needed to bind the He4 nucleus. It is reflected in the difference in mass of the 2 protons and three neutrons in the D and T nuclei and the 2 protrons and 2 neutrons in the He4 nuclei and and free neutron. The mass=energy, that reduced binding energy means the He4 nuclei + free neutron are actually less massive than the D and T. E=mc^2 is applied to the mass deficit to get the energy released per reaction, that is, the kinetic energy, which is about 17.6 Mev in this case or 2.8 x 10-12 Joules. For comparison, chemical reactions, like burning coal or natural gas, release a few ev/reaction, or about a million times less energy per molecule of fuel. That's why fusion research is being pursued. Disclaimer, IAAFR (I am a fusion researcher.)
Don't forget that grain takes a significant amount of oil in the form of fertilizer. I don't know how that compares to beef in a kC/$US measure, but it's not insignificant.
On the expansion of substances, true, liquids and solids expand little compared with gases, but the rate of expansion with temperature for solids that make up the earth's crust are about two orders of magnitude less than that of water. And given the average ocean depth of about 3800 meters, only a small amount of expansion is necessary to raise the sea levels by a noticable amount. I confess that it never occurred to me to take into account the affect of the expansion of the earth's crust, but since below 100 ft or so its pretty much determined by the heating from the core, and it's rate of thermal expansion it negligible compared to water it wouldn't seem to be a significant factor. (A correction, the link in my OP was posted with a space, so I give it again here. Also, I referred to the bulk modulus and I should have said the coefficient of thermal expansion, which is related to the dependence of the modulus on temperature.)
I agree that there are many factors to consider in global warming modelling. You'd be surprised at how many factors are considered. (IANACM)
Alright, I can buy the alien death ray theory,
d u/2006/Textbook/Nodes/chap01/node12.html for a brief discussion.)
but I can't let the bad science go by w/o a comment. The 10% of the ice above the water is there because ice is less dense than water by that amount - that's why it floats! The melting of floating ice doesn't raise water levels. As the poster said, it is the ice that sits on land that contributes to water levels as it melts (ie the bulk of antarctic ice).
That all being said, none of that is the real issue, unless the whole of antarctic ice slides into the ocean. The surprising effect is the finite bulk modulus of water. That is, as it gets warmer, it expands. For example, an increase in ocean temperature of 1 degree K, will raise the level 0.6 m (see http://www.mas.ncl.ac.uk/~sbrooks/book/nish.mit.e
Me too, I could use a pair of hips. Unfortunately,
with joint replacements, the bone is only part
of the story. You need cartelidge and preferable some
good ligaments as well - stuff that goes bye-bye
after artificial joint replacement.
still, one can hope.
Serious scaling issues limit current fusion reactor designs to ~> 1 GW, not very portable.
The most feasible fuel right now does use heavy hydrogen (deuterium) for half it's fuel, the other half is tritium (an even heavier hydrogen) that must be produced on site from lithium.
Fusion reactors do not need cooling in the sense that fission reactors do, however water could be part of a steam cycle for production of electricity.
Deuterium is present at around 140ppm (parts per million), as so heavy water is not a practical fluid for steam cycles.
-----------
fusion, now only 35 yrs away.