This is the problem inherent in the wiki-mindset...then again, who's to say anything released by any corporate news agency is any better (maybe even worse)? Fact-checking and verification is a pretty complex problem that, in the end, will always break down to faith in one party or another.
The ends don't have to be different in temperature at all - when used as a refrigerator (or air conditioner, in this case), they are driven by a motor, which provides the temperature difference. That being said, I've seen small engines that can be driven by the temperature difference between your hand and room temperature, but that's a different story all together.
Correcto-mundo on the manufacturing side, though. Currently the units large enough to do house cooling are hand-made one-by-one and cost in the neighborhood of $50k. They are working on units for car air conditioners though, and we hope to see those within a decade.
No, actually they're using the stirling design as the actual pump - that's the beauty of it. They're looking at using CO2 or helium as the refrigerant as well as the working fluid in the stirling cooler - especially with respect to helium, getting the gas-phase bubbles out of the fluid is as simple as letting it evaporate and leak back into the cooler itself. The design is much simpler this way, and leaks are quite benign.
That being said, helium is a bit more expensive than other refrigerants, and CO2 requires intensely high pressures, so much work is yet to be done. As a heat pump, Stirling cycle engines operate on the theoretical threshold (we evaluate them using the Carnot cycle) of efficiency, so they...well, blow other designs out of the water. For numbers, I don't have any here. To give you some perspective though, I've seend a 40 watt unit freeze the water in the air around it within seconds of being turned on.
While stirling engines are certainly old, the idea of using them as refrigerators is just recently catching on. Here in sleep Athens, OH a company called Global Cooling is the forefront producer of such devices (and is still hand-making a good number of them).
The nice little advantage to these coolers is that they operate with very high COP's, and are limited in lower temperature merely by available power and the boiling point of the working gas. In global cooling's case, Helium is typically used, so temperatures down to around 5K are obtainable (at which point the helium liquifies. Yeah. Cold.) Also, control of the device can be very precise, in that instead of a compressor kicking on and off, it operates constantly, quietly, and with good variable control.
LG is beginning to outfit refrigerators with Stirling pumps because they're so much better than current designs - only problem is they're not mass produced yet. Coleman has a portable unit shown here that is quite a nice unit, albeit very pricey.
One of my professors here at school is one of the pioneers of Stirling refrigeration, so I've been exposed to it a lot. If the whole country switched their refrigerators to stirling compressors, California could shut off its power grid and we'd still have a surplus of energy country-wide.
Looks like if you can use their method to find the current state fast enough, windows doesn't do a great job of reseeding very quickly: I read through the PDF and found this comparison of the LRNG to WRNG (p. 18) -
"Reseeding timeout. The LRNG is feeding the state with system based entropy in every
iteration and whenever system events happen, while the WRNG is reseeding its state only
after generating 128 KBytes of output.
Synchronization. The collection of entropy in the LRNG is asynchronous: whenever there is
an entropy event the data is accumulated in the state of the generator. In the WRNG the
entropy is collected only for a short period of time before the state is reseeded. In the long
period between reseedings there is no entropy collection.
Security implication: The impact of the previous four properties is that forward and
backward security attacks are more severe when applied to the WRNG. The attacks are more
e±cient by twelve orders of magnitude. They reveal the outputs of the generator between
consecutive reseedings, and these reseedings are much more rare in the case of the WRNG.
In some cases, reseeding the LRNG happens every few seconds, while the WRNG is reseeded
every few days, if it is reseeded at all."
How accurate would they have to be with predicting the generator seed times for the keys to work? Would that be a hitch? I'm not an expert in the field, so I honestly don't know.
I would just like to say that the shuttle is the first of its kind. While an incredible amount of engineering has gone into its development, I think it's notable to say that it exists on the forefront of technology as we know it. It's easy to say that 'anyone can do it' from where you're sitting, but to come up with a design out of thin air that exists with the constraints that the space shuttle does is far beyond the reach of most people here.
No design is perfect, and no design is the best. The space shuttle is the first thing to have done what it does - it isn't that hard to imagine worse designs than the shuttle. Look at half the entries for the X Prize that didn't even make it into the atmosphere.
Not where I live. Virtually everyone I work with bikes 2-10 miles to work every day, at least until it's too icy. It's kinda backward here - people who drive are a bit looked down upon, TBH. Perception is reality. Assuming bicycling has a stigma associated with it will simply perpetuate the thought.
Also, what did they do with said list? Surely datamining usually begins with selecting a population and narrowing down based on some criteria, so you have to start with a large population (although I'm not condoning anything the FBI is doing), which puts this pretty much exactly in line with pure McCarthyism - just replace "red" or "communist" with "arab" or "terrorist".
What's scarier, that the credit card companies might be in bed with the government as much as telecoms, or what the FBI will do with their probably ineffective data?
...when the 'press release' takes as much market share from Microsoft as, say, Google's search engine has? Investors try to plan ahead - customers now aren't as important as customers tomorrow. Honestly, if I had my choice I'd picka Google-run mobile simply because I trust them more to be innovative and customer-centered. I think vista has shown us that simply 'owning the market' so-to-speak isn't going to get you incredibly far anymore.
I actually wasn't specifically calling for impeachment - I think that's shaky at best. My post was somewhat in response to an earlier one talking about the global climate and congress's inability to do anything effective to help us, like wasting time on stuff like this that will never get anywhere.
Pitting our candidates against average highschoolers will likely show everyone what we hate to truly believe, that, they're _all_ incompetent. I can't say that I acutally know, but I can't picture anyone on the current rosters understanding the implications, features, and drawbacks of the different alternative energy systems available to abate the impending energy crisis. For example: hydrogen power. Yeah, smooth move on that one. Good luck with all that, too.
Is there any way we can get a leader who hasn't spent their entire career moving up the ranks of a political organization?
I don't think it's so much that a majority of us were "perfectly happy" with our government --see the South Park episode about the giant douche and the turd sandwich -- we voted for who we thought would be more capable, between a whopping two candidates who could possibly win.
I hope the rest of the world understands how truly powerless we Americans feel with respect to controlling our government. Hell, we put the Dems in charge of Congress and they've still failed to do jack squat.
I think that's the point though. I agree, a _good_ teacher in a _good_ school will have no problem with this -- however, we're finding that our teachers and schools will sooner resort to teaching the test to an exorbitant extent (such that it's a main topic of discussion in Ohio's education system, at the least), achieve their assigned metrics, and graduate students who don't know jack squat than teach the students like they should, with confidence that their coverage of the material will guide the student through the exam.
I couldn't word it very well, so I'll quote Wikipedia (which is actually quite accurate here:)
"Critics have argued that the focus on standardized testing (all students in a state take the same test under the same conditions) as the means of assessment encourages teachers to teach a narrow subset of skills that will increase test performance rather than focus on deeper understanding that can readily be transferred to similar problems.[28] For example, if the teacher knows that all of the questions on a math test are simple addition equations (e.g., 2+3=5), then the teacher might not invest any classtime on the practical applications of addition (e.g., story problems) so that there will be more time for the material which is assessed on the test. This is colloquially referred to as "teaching to the test.""
It's a significant enough problem here in Ohio that curriculum developers refer to the NCLB Act ass the E (every) CLB Act.
I totally agree with you. I tutored kids in inner-city Cleveland for the Ohio Graduation Test (thank you for nothing No Child Left Behind), and students whose teachers were giving them A's in mathematics couldn't explain what multiplication was -- one problem was as follows:
You make 9 dollars per hour. If you work 40 hours in a week, how much money do you make per week?
The student didn't know to multiply, and didn't understand why when I began to show them how the problem was solved. There have been many instances of this, where teachers pass students simply to get them out of the classroom, and to collect their state-funded paycheck at the end of the day. The government in Ohio is doing nothing but exacerbating these problems at the moment.
My master's degree is design of an appropriate technology vehicle -- turns out, the appropriate technology movement was abandoned, even to the point of making the phrase a faux-pas in the engineering community based on the idea that it provided mediocre solutions, and that the modern world was simply trying to placate the developing world with sub-par solutions. After projects like the OLPC however, I think it's become evident that applications of simple technology to problems that demand it deserve just as much attention.
Giving someone who can't afford gasoline or buy spare car parts a car is like giving Robinson Caruso a cell phone where he can't get reception.
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This is the problem inherent in the wiki-mindset...then again, who's to say anything released by any corporate news agency is any better (maybe even worse)? Fact-checking and verification is a pretty complex problem that, in the end, will always break down to faith in one party or another.
It's a pun, supposed to sound like "obscene phone call"
The ends don't have to be different in temperature at all - when used as a refrigerator (or air conditioner, in this case), they are driven by a motor, which provides the temperature difference. That being said, I've seen small engines that can be driven by the temperature difference between your hand and room temperature, but that's a different story all together.
Correcto-mundo on the manufacturing side, though. Currently the units large enough to do house cooling are hand-made one-by-one and cost in the neighborhood of $50k. They are working on units for car air conditioners though, and we hope to see those within a decade.
No, actually they're using the stirling design as the actual pump - that's the beauty of it. They're looking at using CO2 or helium as the refrigerant as well as the working fluid in the stirling cooler - especially with respect to helium, getting the gas-phase bubbles out of the fluid is as simple as letting it evaporate and leak back into the cooler itself. The design is much simpler this way, and leaks are quite benign.
That being said, helium is a bit more expensive than other refrigerants, and CO2 requires intensely high pressures, so much work is yet to be done. As a heat pump, Stirling cycle engines operate on the theoretical threshold (we evaluate them using the Carnot cycle) of efficiency, so they...well, blow other designs out of the water. For numbers, I don't have any here. To give you some perspective though, I've seend a 40 watt unit freeze the water in the air around it within seconds of being turned on.
While stirling engines are certainly old, the idea of using them as refrigerators is just recently catching on. Here in sleep Athens, OH a company called Global Cooling is the forefront producer of such devices (and is still hand-making a good number of them).
The nice little advantage to these coolers is that they operate with very high COP's, and are limited in lower temperature merely by available power and the boiling point of the working gas. In global cooling's case, Helium is typically used, so temperatures down to around 5K are obtainable (at which point the helium liquifies. Yeah. Cold.) Also, control of the device can be very precise, in that instead of a compressor kicking on and off, it operates constantly, quietly, and with good variable control.
LG is beginning to outfit refrigerators with Stirling pumps because they're so much better than current designs - only problem is they're not mass produced yet. Coleman has a portable unit shown here that is quite a nice unit, albeit very pricey.
One of my professors here at school is one of the pioneers of Stirling refrigeration, so I've been exposed to it a lot. If the whole country switched their refrigerators to stirling compressors, California could shut off its power grid and we'd still have a surplus of energy country-wide.
Looks like if you can use their method to find the current state fast enough, windows doesn't do a great job of reseeding very quickly: I read through the PDF and found this comparison of the LRNG to WRNG (p. 18) - "Reseeding timeout. The LRNG is feeding the state with system based entropy in every iteration and whenever system events happen, while the WRNG is reseeding its state only after generating 128 KBytes of output. Synchronization. The collection of entropy in the LRNG is asynchronous: whenever there is an entropy event the data is accumulated in the state of the generator. In the WRNG the entropy is collected only for a short period of time before the state is reseeded. In the long period between reseedings there is no entropy collection. Security implication: The impact of the previous four properties is that forward and backward security attacks are more severe when applied to the WRNG. The attacks are more e±cient by twelve orders of magnitude. They reveal the outputs of the generator between consecutive reseedings, and these reseedings are much more rare in the case of the WRNG. In some cases, reseeding the LRNG happens every few seconds, while the WRNG is reseeded every few days, if it is reseeded at all."
How accurate would they have to be with predicting the generator seed times for the keys to work? Would that be a hitch? I'm not an expert in the field, so I honestly don't know.
I would just like to say that the shuttle is the first of its kind. While an incredible amount of engineering has gone into its development, I think it's notable to say that it exists on the forefront of technology as we know it. It's easy to say that 'anyone can do it' from where you're sitting, but to come up with a design out of thin air that exists with the constraints that the space shuttle does is far beyond the reach of most people here. No design is perfect, and no design is the best. The space shuttle is the first thing to have done what it does - it isn't that hard to imagine worse designs than the shuttle. Look at half the entries for the X Prize that didn't even make it into the atmosphere.
I could care less what they do. I save all my open documents to pdf's that everyone can read anyway...what's the issue here?
Good point though, my brother is an airline pilot, but he's terrified of heights. He's fine, as long as he can't look down.
Not where I live. Virtually everyone I work with bikes 2-10 miles to work every day, at least until it's too icy. It's kinda backward here - people who drive are a bit looked down upon, TBH. Perception is reality. Assuming bicycling has a stigma associated with it will simply perpetuate the thought.
Also, what did they do with said list? Surely datamining usually begins with selecting a population and narrowing down based on some criteria, so you have to start with a large population (although I'm not condoning anything the FBI is doing), which puts this pretty much exactly in line with pure McCarthyism - just replace "red" or "communist" with "arab" or "terrorist".
What's scarier, that the credit card companies might be in bed with the government as much as telecoms, or what the FBI will do with their probably ineffective data?
...when the 'press release' takes as much market share from Microsoft as, say, Google's search engine has? Investors try to plan ahead - customers now aren't as important as customers tomorrow. Honestly, if I had my choice I'd picka Google-run mobile simply because I trust them more to be innovative and customer-centered. I think vista has shown us that simply 'owning the market' so-to-speak isn't going to get you incredibly far anymore.
The US Congress is a circus. Never stopped. :)
I actually wasn't specifically calling for impeachment - I think that's shaky at best. My post was somewhat in response to an earlier one talking about the global climate and congress's inability to do anything effective to help us, like wasting time on stuff like this that will never get anywhere.
Iraq...Iran...Pakistan....anyone else we can piss off before congress does anything?
Current is stored in inductors, not capacitors. You CAN store AC voltage in a capacitor, it just behaves differently than DC at different frequencies.
Overheard from military war room: "I can dance all day! I can dance all day! Try and hit me! Try and hit me!"
Good point. I concur.
Pitting our candidates against average highschoolers will likely show everyone what we hate to truly believe, that, they're _all_ incompetent. I can't say that I acutally know, but I can't picture anyone on the current rosters understanding the implications, features, and drawbacks of the different alternative energy systems available to abate the impending energy crisis. For example: hydrogen power. Yeah, smooth move on that one. Good luck with all that, too.
Is there any way we can get a leader who hasn't spent their entire career moving up the ranks of a political organization?
I don't think it's so much that a majority of us were "perfectly happy" with our government --see the South Park episode about the giant douche and the turd sandwich -- we voted for who we thought would be more capable, between a whopping two candidates who could possibly win.
I hope the rest of the world understands how truly powerless we Americans feel with respect to controlling our government. Hell, we put the Dems in charge of Congress and they've still failed to do jack squat.
I think that's the point though. I agree, a _good_ teacher in a _good_ school will have no problem with this -- however, we're finding that our teachers and schools will sooner resort to teaching the test to an exorbitant extent (such that it's a main topic of discussion in Ohio's education system, at the least), achieve their assigned metrics, and graduate students who don't know jack squat than teach the students like they should, with confidence that their coverage of the material will guide the student through the exam.
I couldn't word it very well, so I'll quote Wikipedia (which is actually quite accurate here:) "Critics have argued that the focus on standardized testing (all students in a state take the same test under the same conditions) as the means of assessment encourages teachers to teach a narrow subset of skills that will increase test performance rather than focus on deeper understanding that can readily be transferred to similar problems.[28] For example, if the teacher knows that all of the questions on a math test are simple addition equations (e.g., 2+3=5), then the teacher might not invest any classtime on the practical applications of addition (e.g., story problems) so that there will be more time for the material which is assessed on the test. This is colloquially referred to as "teaching to the test."" It's a significant enough problem here in Ohio that curriculum developers refer to the NCLB Act ass the E (every) CLB Act.
I totally agree with you. I tutored kids in inner-city Cleveland for the Ohio Graduation Test (thank you for nothing No Child Left Behind), and students whose teachers were giving them A's in mathematics couldn't explain what multiplication was -- one problem was as follows:
You make 9 dollars per hour. If you work 40 hours in a week, how much money do you make per week?
The student didn't know to multiply, and didn't understand why when I began to show them how the problem was solved. There have been many instances of this, where teachers pass students simply to get them out of the classroom, and to collect their state-funded paycheck at the end of the day. The government in Ohio is doing nothing but exacerbating these problems at the moment.
My master's degree is design of an appropriate technology vehicle -- turns out, the appropriate technology movement was abandoned, even to the point of making the phrase a faux-pas in the engineering community based on the idea that it provided mediocre solutions, and that the modern world was simply trying to placate the developing world with sub-par solutions. After projects like the OLPC however, I think it's become evident that applications of simple technology to problems that demand it deserve just as much attention. Giving someone who can't afford gasoline or buy spare car parts a car is like giving Robinson Caruso a cell phone where he can't get reception.