I hope its a waste of money, but there is a tiny chance it is a lot worse: something listening might actually be able to come here. Historically when the "guys on the ships" meet the "guys on the shore", the guys on the shore don't do very well. One could also make an argument that if you detect an alien culture, your best bet is to launch a relativistic bomb (or the information equivalent).
"All data" can be confusing. Honest to god "raw" data is basically useless - do you really want raw digitizer data from a million sensors (if so, join the research collaboration)? Processed data (temperature trends, etc) might be interesting, but people often make mistakes processing data, and then correct the mistakes before they publish. I've done lots of temporary analysis of data that later turned out to be incorrect: either I or someone else found the mistakes. Looking at unpublished data is sort of like looking at a snapshot of code in development - you might learn something, but it could give an incorrect idea of the reliability of the final code. Cherry picking data and emails is of course silly - at least where I work (SLAC) people are not careful about what they put in internal emails, and lots of things get said in the middle of a late-shift rant.
I agree with you. This problem is especially bad because there are some legal but immoral activities (like having an affair) that many people will commit crimes to cover up. It may be perfectly legal for a politician to have sex with his same-sex, adult assistant, but someone could use that information to blackmail him / her into doing something illegal.
A separate problem is that the severity of laws changes. When I was growing up, driving drunk was sort of funny. Illegal, but not serious. Now it is considered a serious crime. In 30 years, maybe speeding (kills lots of people) will be considered a serious crime. Various recorded surveillance could be used to show that someone....exceeded the posted speed limit almost every day.....at some time in the past.
Corner Cubes. Somewhat seriously, it would be pretty easy to figure out what wavelength they are using and build high reflectivity mirrors. Rather bad for your radar cross section though.
Still don't see how this will stop suicide bombers.
By providing a legal path for corporate dollars to influence politics, at least we can keep an eye on it. If lobbying was not legal, it would just go underground. I really don't like the solution we have, but I don't know how to make it better. Serious question: are there any large governments that clearly have less corruption than the US system, and how do they do it?
I agree that NIF is mostly a stockpile security program. We can't do critical tests anymore but need some way to make sure the existing weapons will still work. (Nothing worse than a nuclear weapon that MIGHT work).
The public is much happier with energy research - and the work does have some fusion energy application.
There are other laser technologies that might possibly scale to high repetition rates, so it isn't impossible, but personally I don't think this approach will ever be practical.
The experiments will teach us something about inertial confinement fusion - and other drive options (like ion beams) might be more practical.
NIF can be a good test bed for fusion research, but it isn't a practical reactor. We would need much more efficient, and higher repetition rate lasers.
These days synchronizing lasers to microseconds is easy. At LCLS/SLAC we synchronize our conventional and X-ray laser to 100 femtoseconds. We've also done 40 km of fiber to about 1 picosecond (and I think other labs have done better)
There is an old Russian joke about a lab that is working to turn feces into peanut-butter. When the party official comes by to see how the work is going, the lab director replies "Wonderful - see how well it spreads".
The problem with space elevator is the cable - everything else is trivial
If a material (like carbon nanotubes) could be made that had the required strength, and was inexpensive enough to produce >10,000 Km of cable, that material could be used to drastically reduce the cost and weight of conventional launch vehicles.
The fuel cost for a conventional launch is tiny - $50/Kg, while the total launch cost is ~$10,000/Kg. (this is for real existing launch vehicles) Fuel costs aren't the issue.
Are the brakes controlled electronically? In any car I know of, the brakes can stop the car even at full throttle. Of course its possible for the anti-skid system to disable the brakes, but I would hope that is a completely separate system...
Upgraded 3 machines. (one newish with AMD quad-core, one old IBM thinkpad x60, one ancient PC), only problem was a minor display issue with the ubuntu-satanic themes.
Overall, very smooth - for me.
"All right, apart from better sanitation, medicine, education, irrigation, public health, roads, freshwater, public order....What have the Romans done for us...."
I expect that in 20 years the infrastructure will be in worse shape and we will be even further from expanding through the universe. With the upcoming demographic disaster, increasing health care costs, environmental costs, etc this may the last chance for this civilization to get into space.
If the US became as efficient at health care as Europe, (and allowed more people to die) the extra TRILLION dollars a year would go a long way to allowing a bunch of interesting programs, including space colonization.
What we have to gain from space exploration is...the rest of the universe.
As an aside to the original post - relative to the mass required to build a colony I don't think we save a lot by doing one-way trips.
The Dayton museum is absolutely fantastic! Be sure to sign up to go to the experimental hanger, they have the only surviving B-70 Valkyrie, possibly the most fantastic flying machine ever constructed.
The reason people are so interested in CO2 is that it is the most difficult to fix. Modern auto engines can have very low emissions of everything other than C02 - all the other emissions are just side effects. The CO2 is a primary product of combustion and the only way to produce less is to burn less carbon in your fuel to begin with.
The problem with 230mpg claims is that they make the care look greener than it is. The metric should either be $/mile (including electricity costs), or grams of CO2 per mile.
No, it would still be 150X colder. If you measure from absolute zero the temperature ration doesn't depend on which units you use. 300K to 2K is X150. 600X to 4X (where X is some temperature scale I just made up) is still 150X colder. This doesn't work for F or C degrees because zero is not at absolute zero.
There is always a reliability / cost tradeoff. If they had inspected all of the joints they would not have had this problem - easy to say in hindsight. If they had double-checked everything that went into building the machine it would have been too expensive to build.
It is the sort of cutting edge you get when you push any technology beyond the existing limits. The same way that building the densest chip or fastest airplane is cutting edge. The scale-up has presented new problems that smaller machines did not have
We had to call LCLS the first "hard X-ray laser", so they have to call FLASH the first "soft" X-ray laser.
Basically Soft X-rays are lower energy (maybe below 1 kV (I'm not sure where the boundry is), hard X-rays are above that.
Otherwise it is a very interesting science experiment for understanding exotic states of matter, but isn't likely to lead to transparent structural materials.
Reactors won't explode like a nuclear bomb, but they can in principal explode. The classic view of a nuclear reaction is that a neutron causes a uranium nucleus to fission, releasing more neutrons. Some of those neutrons are absorbed by the control rods, some cause more fissions. If on average the neutrons produce a growing number of fissions, you have a chain reaction. So far so good. In that simple model though the reactor is impossible to control. If the control rods absorb too many neutrons, the reaction dies away. If they absorb too few, it grows exponentially. The time constant (in this simple model) would be VERY FAST - probably microseconds. You couldn't possibly move the control rods fast enough to keep the reactor running at a stable power.
A couple of things let you control the reaction: in a conventional power reactor the neutrons are moderated (slowed down) and the uranium has a higher cross section for slower neutrons. If the reaction rate starts to grow, the moderator gets hot, the neutrons get faster and the reaction slows down - a bit of negative feedback. This helps, but isn't enough by itself to make the reactor stable.
The other important item is the fuel mix. Not all of the neutrons are produced immediately in the fission reaction, some are produced later (seconds to hours) from radioactive decay. You can run the reactor in a state where it is sub critical for the prompt neutrons, but still above critical for the delayed neutrons. That slows the exponential growth or decay rate to something you can control. Of course as the reactor operates, the fuel mix changes. U235 fissions. U238 breeds plutonium. The ration of prompt to delayed neutrons changes. People who operate reactors calculate the fuel mix as the reactor operates to be sure they have a reasonable stability margin.
Having said all that, the safety record for nuclear power (including Chernobyl) is extremely good compared to other energy sources. The safety record for reactors in western countries is spectacularly good. I absolutely support building more nuclear reactors as the most practical solution to energy / environmental problems.
An airliner flying in the jet stream doesn't slow it down significantly. There is a small effect when the airliner enters the jet stream (and accelerates), but I think in cruise flight the effect is very small.
A power generating kite extracts energy from the jet stream. The description of enough energy to power civilization is surprising to me (though it may be true), are they sure they have counted that the kites will slow down the jet stream?
Also the jet stream moves around and changes direction a lot, it can flow anywhere across the US (I don't know the pattern over the rest of the earth), mostly west to east, but can be due north or south. I don't know how you would move the anchorages for the kites around quickly enough to keep up.
Is the distinction between real and virtual goods that clear? I can buy music, videos, games and game upgrade packages online. If I pay to listen to music in an online game, is that a real or a virtual good. What if the performer is also in the game? What if I want to sell copies of music made in a game to the outside world?
I agree with your statements. I would add though that cars are not a particularly good place to apply new energy technology. Cars are low usage items: A typical car engine operates for only about 10% of calendar time, and most of that time it is at around 10% of maximum output. In addition car engines are very constrained by weight, noise, maintainability, and dealing with harsh and variable environments.
Since a significant fraction of fossil fuels are consumed in fixed power plants, these seem a much better place to spend capital to reduce CO2 emissions. Power plants operate at high duty factors (as near 100% as their reliability and and maintenance schedule will allow).
We have a limited amount of capital to invest in reducing CO2, we should invest it where it will do the most good.
I have to agree. I have an aging Lenovo laptop that I will be replacing this year. It was a nice (but expensive) computer. Now I need to put Lenovo at the next to the bottom of my purchase list (just above Sony). I just can't risk having pop-up adds in the middle of a presentation (and embedding adds annoys me).
Why on earth would they cheapen their brand name that way????????
BTW: It doesn't matter if there is an easy way to turn it off. I don't want their F'in adds, not even once.
The problem is that if the attorney is every planning to run for public office, the threat of publicly revealing that he likes (legal) chubby-porn will trash his chances. The threat of revealing legal, but embarrassing information works on a lot of people. In the US it is legal to have an affair, but people have committed murder to keep affairs secret.
Slashdot Mirror
I hope its a waste of money, but there is a tiny chance it is a lot worse: something listening might actually be able to come here. Historically when the "guys on the ships" meet the "guys on the shore", the guys on the shore don't do very well. One could also make an argument that if you detect an alien culture, your best bet is to launch a relativistic bomb (or the information equivalent).
"All data" can be confusing. Honest to god "raw" data is basically useless - do you really want raw digitizer data from a million sensors (if so, join the research collaboration)? Processed data (temperature trends, etc) might be interesting, but people often make mistakes processing data, and then correct the mistakes before they publish. I've done lots of temporary analysis of data that later turned out to be incorrect: either I or someone else found the mistakes. Looking at unpublished data is sort of like looking at a snapshot of code in development - you might learn something, but it could give an incorrect idea of the reliability of the final code. Cherry picking data and emails is of course silly - at least where I work (SLAC) people are not careful about what they put in internal emails, and lots of things get said in the middle of a late-shift rant.
I agree with you. This problem is especially bad because there are some legal but immoral activities (like having an affair) that many people will commit crimes to cover up. It may be perfectly legal for a politician to have sex with his same-sex, adult assistant, but someone could use that information to blackmail him / her into doing something illegal. A separate problem is that the severity of laws changes. When I was growing up, driving drunk was sort of funny. Illegal, but not serious. Now it is considered a serious crime. In 30 years, maybe speeding (kills lots of people) will be considered a serious crime. Various recorded surveillance could be used to show that someone....exceeded the posted speed limit almost every day.....at some time in the past.
Corner Cubes. Somewhat seriously, it would be pretty easy to figure out what wavelength they are using and build high reflectivity mirrors. Rather bad for your radar cross section though. Still don't see how this will stop suicide bombers.
By providing a legal path for corporate dollars to influence politics, at least we can keep an eye on it. If lobbying was not legal, it would just go underground. I really don't like the solution we have, but I don't know how to make it better. Serious question: are there any large governments that clearly have less corruption than the US system, and how do they do it?
I agree that NIF is mostly a stockpile security program. We can't do critical tests anymore but need some way to make sure the existing weapons will still work. (Nothing worse than a nuclear weapon that MIGHT work). The public is much happier with energy research - and the work does have some fusion energy application. There are other laser technologies that might possibly scale to high repetition rates, so it isn't impossible, but personally I don't think this approach will ever be practical. The experiments will teach us something about inertial confinement fusion - and other drive options (like ion beams) might be more practical.
NIF can be a good test bed for fusion research, but it isn't a practical reactor. We would need much more efficient, and higher repetition rate lasers.
These days synchronizing lasers to microseconds is easy. At LCLS/SLAC we synchronize our conventional and X-ray laser to 100 femtoseconds. We've also done 40 km of fiber to about 1 picosecond (and I think other labs have done better)
There is an old Russian joke about a lab that is working to turn feces into peanut-butter. When the party official comes by to see how the work is going, the lab director replies "Wonderful - see how well it spreads". The problem with space elevator is the cable - everything else is trivial If a material (like carbon nanotubes) could be made that had the required strength, and was inexpensive enough to produce >10,000 Km of cable, that material could be used to drastically reduce the cost and weight of conventional launch vehicles. The fuel cost for a conventional launch is tiny - $50/Kg, while the total launch cost is ~$10,000/Kg. (this is for real existing launch vehicles) Fuel costs aren't the issue.
Are the brakes controlled electronically? In any car I know of, the brakes can stop the car even at full throttle. Of course its possible for the anti-skid system to disable the brakes, but I would hope that is a completely separate system...
Upgraded 3 machines. (one newish with AMD quad-core, one old IBM thinkpad x60, one ancient PC), only problem was a minor display issue with the ubuntu-satanic themes. Overall, very smooth - for me.
"All right, apart from better sanitation, medicine, education, irrigation, public health, roads, freshwater, public order....What have the Romans done for us...."
I expect that in 20 years the infrastructure will be in worse shape and we will be even further from expanding through the universe. With the upcoming demographic disaster, increasing health care costs, environmental costs, etc this may the last chance for this civilization to get into space. If the US became as efficient at health care as Europe, (and allowed more people to die) the extra TRILLION dollars a year would go a long way to allowing a bunch of interesting programs, including space colonization. What we have to gain from space exploration is...the rest of the universe. As an aside to the original post - relative to the mass required to build a colony I don't think we save a lot by doing one-way trips.
The Dayton museum is absolutely fantastic! Be sure to sign up to go to the experimental hanger, they have the only surviving B-70 Valkyrie, possibly the most fantastic flying machine ever constructed.
The reason people are so interested in CO2 is that it is the most difficult to fix. Modern auto engines can have very low emissions of everything other than C02 - all the other emissions are just side effects. The CO2 is a primary product of combustion and the only way to produce less is to burn less carbon in your fuel to begin with. The problem with 230mpg claims is that they make the care look greener than it is. The metric should either be $/mile (including electricity costs), or grams of CO2 per mile.
No, it would still be 150X colder. If you measure from absolute zero the temperature ration doesn't depend on which units you use. 300K to 2K is X150. 600X to 4X (where X is some temperature scale I just made up) is still 150X colder. This doesn't work for F or C degrees because zero is not at absolute zero.
There is always a reliability / cost tradeoff. If they had inspected all of the joints they would not have had this problem - easy to say in hindsight. If they had double-checked everything that went into building the machine it would have been too expensive to build.
It is the sort of cutting edge you get when you push any technology beyond the existing limits. The same way that building the densest chip or fastest airplane is cutting edge. The scale-up has presented new problems that smaller machines did not have
We had to call LCLS the first "hard X-ray laser", so they have to call FLASH the first "soft" X-ray laser. Basically Soft X-rays are lower energy (maybe below 1 kV (I'm not sure where the boundry is), hard X-rays are above that. Otherwise it is a very interesting science experiment for understanding exotic states of matter, but isn't likely to lead to transparent structural materials.
Reactors won't explode like a nuclear bomb, but they can in principal explode. The classic view of a nuclear reaction is that a neutron causes a uranium nucleus to fission, releasing more neutrons. Some of those neutrons are absorbed by the control rods, some cause more fissions. If on average the neutrons produce a growing number of fissions, you have a chain reaction. So far so good. In that simple model though the reactor is impossible to control. If the control rods absorb too many neutrons, the reaction dies away. If they absorb too few, it grows exponentially. The time constant (in this simple model) would be VERY FAST - probably microseconds. You couldn't possibly move the control rods fast enough to keep the reactor running at a stable power. A couple of things let you control the reaction: in a conventional power reactor the neutrons are moderated (slowed down) and the uranium has a higher cross section for slower neutrons. If the reaction rate starts to grow, the moderator gets hot, the neutrons get faster and the reaction slows down - a bit of negative feedback. This helps, but isn't enough by itself to make the reactor stable. The other important item is the fuel mix. Not all of the neutrons are produced immediately in the fission reaction, some are produced later (seconds to hours) from radioactive decay. You can run the reactor in a state where it is sub critical for the prompt neutrons, but still above critical for the delayed neutrons. That slows the exponential growth or decay rate to something you can control. Of course as the reactor operates, the fuel mix changes. U235 fissions. U238 breeds plutonium. The ration of prompt to delayed neutrons changes. People who operate reactors calculate the fuel mix as the reactor operates to be sure they have a reasonable stability margin. Having said all that, the safety record for nuclear power (including Chernobyl) is extremely good compared to other energy sources. The safety record for reactors in western countries is spectacularly good. I absolutely support building more nuclear reactors as the most practical solution to energy / environmental problems.
An airliner flying in the jet stream doesn't slow it down significantly. There is a small effect when the airliner enters the jet stream (and accelerates), but I think in cruise flight the effect is very small. A power generating kite extracts energy from the jet stream. The description of enough energy to power civilization is surprising to me (though it may be true), are they sure they have counted that the kites will slow down the jet stream? Also the jet stream moves around and changes direction a lot, it can flow anywhere across the US (I don't know the pattern over the rest of the earth), mostly west to east, but can be due north or south. I don't know how you would move the anchorages for the kites around quickly enough to keep up.
Is the distinction between real and virtual goods that clear? I can buy music, videos, games and game upgrade packages online. If I pay to listen to music in an online game, is that a real or a virtual good. What if the performer is also in the game? What if I want to sell copies of music made in a game to the outside world?
I agree with your statements. I would add though that cars are not a particularly good place to apply new energy technology. Cars are low usage items: A typical car engine operates for only about 10% of calendar time, and most of that time it is at around 10% of maximum output. In addition car engines are very constrained by weight, noise, maintainability, and dealing with harsh and variable environments. Since a significant fraction of fossil fuels are consumed in fixed power plants, these seem a much better place to spend capital to reduce CO2 emissions. Power plants operate at high duty factors (as near 100% as their reliability and and maintenance schedule will allow). We have a limited amount of capital to invest in reducing CO2, we should invest it where it will do the most good.
I have to agree. I have an aging Lenovo laptop that I will be replacing this year. It was a nice (but expensive) computer. Now I need to put Lenovo at the next to the bottom of my purchase list (just above Sony). I just can't risk having pop-up adds in the middle of a presentation (and embedding adds annoys me). Why on earth would they cheapen their brand name that way???????? BTW: It doesn't matter if there is an easy way to turn it off. I don't want their F'in adds, not even once.
The problem is that if the attorney is every planning to run for public office, the threat of publicly revealing that he likes (legal) chubby-porn will trash his chances. The threat of revealing legal, but embarrassing information works on a lot of people. In the US it is legal to have an affair, but people have committed murder to keep affairs secret.