There are a few things that will make a difference in a cable in some cases. For example, depending on the amount of electrical noise nearby, shielded cables may make sense -- but I would expect that's the exception rather than the rule. The other obvious thing is connectors -- mechanically sound connectors that don't corrode over time, and don't come loose, are important. But that's really a ease of use question, mostly, rather than a sound quality one.
I'm not an audiophile, but I do enjoy good sound, and I've done analog signals work at similar frequencies and levels of precision. My experience has been that you only really need to worry about things like shielding in electrically noisy environments.
Not only am I unintimidated by litigation; I sometimes rather miss it.
Good to see a little guy who seriously intends to go not only to trial but to final judgement against a big patent bully. They definitely picked the wrong person to pick on.
The point about the infinite tape comment was that, in the sense it is normally used, "Turing complete" is not sufficient to run Linux, even after you port the code over. You need a Turing complete instruction set, and sufficient memory. One could debate the necessity of IO devices as well, I suppose.
No, the issue with supercaps isn't voltage, when it comes to cars. (I'll ignore catching lightning; it's a bad power source for lots of reasons.) A few in series gets into the range that power electronics can work with easily enough. No, the problem with supercaps is that they're still heavier than even lead acid batteries, and expensive. They're getting cheaper and better, though -- and last I looked into it, there were pieces of them in labs that were competitive with batteries. The best ones I've found that you can buy are about 1/10th the energy density, which is tantalizingly close.
I'm hopeful we'll see them beginning to appear in commercial applications in a few years, though I imagine the first place they get used won't be cars. If they can compete on weight with batteries, you could imagine charging your cell phone / iPod / laptop in a tenth the time it currently takes...
First, this is the Difference Engine No. 2, not the Analytical Engine. It's not Turing complete.
Second, the usual restriction on running something like Linux is lack of memory, not lack of a Turing-complete instruction set. Or, looked at another way, no one has ever or will ever build a Turing-complete machine, because they'll run into difficulty with the infinite tape.
It's far more specialized than that. It basically computes values of a polynomial from a starting set (interpolate / extrapolate). It doesn't have an explicit fexible divide operation. Exactly what sort of error you get out is going to depend on how you carry out the division, but most likely you would do exp(log(a) - log(b)), which would produce a very large negative number for log(b) (an incorrect result, obviously), and a very large number for the result. It might or might not overflow, depending on the precision of your approximating polynomials for log and exp at the values of interest.
Alternately, they'll release degraded versions of the images. If they release a degraded image, explain that they did so for national security reasons, explain the process by which it was degraded (we lowered the resolution by using this algorithm), and allowed an expert witness to verify said process while under confidentiality requirements, that would even be fairly reasonable.
I am completely, 100%, against domestic spying programs like this. But if the government wants to use *less* evidence than it has available, I have no objections to them presenting only some of that evidence -- provided the remainder would not be exonerating evidence or some such. And national security actually seems like a valid reason for doing so, in such a case.
Not to mention that the Constitution and Bill of Rights don't grant any rights at all. Not a single one. They merely recognize some of the rights that all people already have. That's why they're called rights, not privileges or some such, after all.
Also... while it's a technicality, air *is* conductive. It just has a very high impedance. It *will* conduct electricity, and I'm pretty near certain you've seen it happen: it's called lightening.
If you want to get all technical about it, you're basically wrong. The resistivity of air is exceedingly high. However, like all insulators, it has a breakdown strength, and at electric field strengths beyond that, the conduction mode changes. It's not simply a very high value resistor -- nonconducting air and conducting air are two very different states, which is the reason lightning happens. The air doesn't conduct, allowing the charge to build higher and higher, until the field is strong enough that breakdown begins.
For materials with resistivity as high as air in its normal state, it's not reasonable to call them conducting except under the most extreme conditions. Typical resistance values for air paths found in computers would be on the order of petaohms. While there is some sense in which a petaohm resistor conducts, the cases where that is relevant are so vanishingly rare that it is far more productive to the discussion to simply say it doesn't conduct.
This is one of those cases. Claiming that air is conductive is detrimental to the discussion at best.
You do realize that HTML is the old markup language, and BBCode and such are the new, invented ones, right? And furthermore, that/. is older than BBCode? The perfectly good standard is HTML, not BBCode.
The TV tax is also a silly silly idea, if you assume TV ownership is a good thing (whether that's the case is a different question). And since nearly everyone pays it anyway, it ends up being equivalent to a regressive general tax -- which means it would be better all around to simply take the money from the general fund and increase the general tax rate accordingly.
Why is this a tax on Internet access, rather than being drawn from the general fund? Net access is something that is good for people to have, so putting a tax on it is a bad thing, especially since it's a regressive tax (people with lower income will spend proportionally more of their income on net access, so proportionally more of their income goes to the tax).
Taxes on specific things, rather than broad taxes that go to the general fund, should be for one of two reasons. Either the tax should be intended to discourage something (whether that's an ethical reason I'll leave to others, but if society making such judgements is reasonable then the tax is reasonable), or the tax should be intended to internalize an internal cost. So taxes on carbon emissions and other polluting activities make sense (though imho tradable permits are better), because there is a normally external cost paid by society that should be shifted to the ones creating the problem. Internet access is neither of those things -- and public content is most certainly not an external cost.
XCOR Aerospace does this. Anyone who works on a vehicle, or manages someone who does, gets a ride in the vehicle. It's actually important that it be everyone, not just the high level people -- or, if you can't do everyone for logistical reasons, a randomly chosen sample. Managers can motivate the people they manage, but only within limits. It's not fair to ask the manager to trust his group's work if the rest of the group won't do the same.
I'm told this was also done for Vietnam War helicopter maintenence -- after major servicing, the chief mechanic rode on the checkout flight.
(Now, if only someone could show me how to embed nice links here...:) )
It's a web site. You use HTML. Why most forums insist on making up their own weird and varying markup systems when they're busy using a perfectly good one is completely beyond me, but somehow it's common enough that people expect it.
(You may have to change your posting options to "HTML formatted." You may then end up wanting to actually include formatting tags in your comments in order to get them to display properly.)
If they'd done this from the start, no one would be complaining. In Linux or UNIX, if a program wants elevated privileges, it requires user intervention. The result is that programs don't expect to have superuser privileges if they don't actually need them, and everyone is happy because the only things that have to be done as root are things you'd expect to require root access.
All this is happening in the chamber, not the nozzle. After the nozzle throat (the constriction before the expansion bell), the gas is supersonic and so can't really resonate (sound waves can't travel backward). The oscillations in question happen right at the injector face. Aerospike engines have a very different nozzle, but everything before the throat is fairly conventional -- so they'd exhibit the same problems, and measurement would be no easier.
People have built see-through chambers before, at varying levels of sophistication. This includes everything from liquid-cooled silica glass with LOX/LH2 engines to low-pressure oxygen/acrylic hybrids. The problem isn't seeing through the engine wall, it's seeing through the flame. That's what makes the photography they did so clever.
No, there's no angular momentum involved. The waves progress around the circumference, but the net average angular motion of the gas is zero. It's purely a wave phenomenon, and there are plenty of other resonant modes -- radial, tangential, etc. This just happens to be the mode they studied first.
The problem is one of Q factor. Resonant modes in an engine *will* be excited -- engines tend to have fairly distinctive character when you look at the FFT of the chamber pressure trace (a fancy way of saying engines have their own unique sound). If the resonance has a high Q factor, then the modest input power available at that frequency will build rapidly, and couple into the combustion process or injector and gain even more energy. If the Q factor is low, then it will only show up as a small peak above the white noise floor in the FFT, and there will never be a problem. It's the difference between a clock pendulum and a much cruder pendulum with a high friction bearing (say, a strip of wood with a rough hole in it hanging from a peg) -- a tiny energy input will cause the clock pendulum to make large swings, if presented at the correct frequency. But the crude pendulum will make tiny swings for a tiny energy input, whether you have the frequency perfect or not.
Sutton discusses that resonant mode (spinning tangential) briefly in Rocket Propulsion Elements (pg 353, 7th ed). There are plenty of more detailed discussions of combustion instability in general elsewhere in the literature. There are a variety of other resonant modes as well, this just happens to be the one the researchers looked at.
You can indeed add features to the chamber to de-tune it. It's anything but simple, though, and is mostly trial and error at present. Making the features not burn up is tricky; that part of why they're often added as part of the injector, since the injectors are cooled by the propellant flowing through them.
The second party has to accept the contract. The man being sued did not accept the contract, and no one is claiming he did. Since there is no dispute, there is no contract law question.
IANAL, but the EFF brief does a very good job of explaining why the CD was abandoned in the legal sense of California law. It meets the requirements of the abandonment law as far as I can see -- they gave up possession, and their actions demonstrated that they did not intend to regain possession at any time in the future. Is there any legal reason that isn't sufficient to constitute abandonment? UMG says it wasn't abandoned, but offer nothing beyond that assertion as evidence -- and the EFF presents case law that says that assertion is insufficient to create a question of fact. So why shouldn't I believe the EFF brief?
As I said, I'm not a lawyer, but I'm interested, assuming the legalese doesn't get overly dense. The EFF brief was quite readable.
Titanium may melt at 1900K, but rocket chambers operate in the realm of 2500-3500K. They have to be cooled, and copper is the material of choice for the same reason it makes good CPU heat sinks -- excellent thermal conductivity. Some older thrust chambers were made of steel (WAC Corporal, iirc), and it works at low chamber pressures (less heat flux), but it doesn't work as well and there are corrosion issues in storage. As performance increases and chamber pressures rise, metals other than copper look less and less appealing.
Some nozzles are uncooled in the aft portion (as the gas expands and accelerates, it cools down, so the environment gets easier to handle). The Kestrel engine used in the Falcon 1 upper stage, for example, has a radiatively cooled Niobium nozzle. Titanium has been used, but Niobium and a few others tend to perform better in that environment -- the combination of hot reactive gases is hard to handle.
The US is the same way, and the EFF brief explains all the gory details with plenty of references. Furthermore, gifts trigger the first sale doctrine -- again, there is plenty of precedent -- and stickers on the CDs are not enough to prevent the doctrine from taking effect.
First sale absolutely applies, as there is plenty of legal precedent that gifts count as sales for purposes of the first sale doctrine. The EFF brief has all the detailed arguments, and plenty of references. It's also quite readable, and quite thorough about dismantling UMG's arguments.
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There are a few things that will make a difference in a cable in some cases. For example, depending on the amount of electrical noise nearby, shielded cables may make sense -- but I would expect that's the exception rather than the rule. The other obvious thing is connectors -- mechanically sound connectors that don't corrode over time, and don't come loose, are important. But that's really a ease of use question, mostly, rather than a sound quality one.
I'm not an audiophile, but I do enjoy good sound, and I've done analog signals work at similar frequencies and levels of precision. My experience has been that you only really need to worry about things like shielding in electrically noisy environments.
My favorite quote:
Not only am I unintimidated by litigation; I sometimes rather miss it.Good to see a little guy who seriously intends to go not only to trial but to final judgement against a big patent bully. They definitely picked the wrong person to pick on.
The point about the infinite tape comment was that, in the sense it is normally used, "Turing complete" is not sufficient to run Linux, even after you port the code over. You need a Turing complete instruction set, and sufficient memory. One could debate the necessity of IO devices as well, I suppose.
No, the issue with supercaps isn't voltage, when it comes to cars. (I'll ignore catching lightning; it's a bad power source for lots of reasons.) A few in series gets into the range that power electronics can work with easily enough. No, the problem with supercaps is that they're still heavier than even lead acid batteries, and expensive. They're getting cheaper and better, though -- and last I looked into it, there were pieces of them in labs that were competitive with batteries. The best ones I've found that you can buy are about 1/10th the energy density, which is tantalizingly close.
I'm hopeful we'll see them beginning to appear in commercial applications in a few years, though I imagine the first place they get used won't be cars. If they can compete on weight with batteries, you could imagine charging your cell phone / iPod / laptop in a tenth the time it currently takes...
As I'm sure you're aware, XCOR Aerospace built both the EZ-Rocket (rocket-powered LongEZ) and the first of the Rocket Racers.
They've been mentioned here recently for the upcoming Lynx spaceplane, as well.
First, this is the Difference Engine No. 2, not the Analytical Engine. It's not Turing complete.
Second, the usual restriction on running something like Linux is lack of memory, not lack of a Turing-complete instruction set. Or, looked at another way, no one has ever or will ever build a Turing-complete machine, because they'll run into difficulty with the infinite tape.
It's far more specialized than that. It basically computes values of a polynomial from a starting set (interpolate / extrapolate). It doesn't have an explicit fexible divide operation. Exactly what sort of error you get out is going to depend on how you carry out the division, but most likely you would do exp(log(a) - log(b)), which would produce a very large negative number for log(b) (an incorrect result, obviously), and a very large number for the result. It might or might not overflow, depending on the precision of your approximating polynomials for log and exp at the values of interest.
Alternately, they'll release degraded versions of the images. If they release a degraded image, explain that they did so for national security reasons, explain the process by which it was degraded (we lowered the resolution by using this algorithm), and allowed an expert witness to verify said process while under confidentiality requirements, that would even be fairly reasonable.
I am completely, 100%, against domestic spying programs like this. But if the government wants to use *less* evidence than it has available, I have no objections to them presenting only some of that evidence -- provided the remainder would not be exonerating evidence or some such. And national security actually seems like a valid reason for doing so, in such a case.
Not to mention that the Constitution and Bill of Rights don't grant any rights at all. Not a single one. They merely recognize some of the rights that all people already have. That's why they're called rights, not privileges or some such, after all.
If you want to get all technical about it, you're basically wrong. The resistivity of air is exceedingly high. However, like all insulators, it has a breakdown strength, and at electric field strengths beyond that, the conduction mode changes. It's not simply a very high value resistor -- nonconducting air and conducting air are two very different states, which is the reason lightning happens. The air doesn't conduct, allowing the charge to build higher and higher, until the field is strong enough that breakdown begins.
For materials with resistivity as high as air in its normal state, it's not reasonable to call them conducting except under the most extreme conditions. Typical resistance values for air paths found in computers would be on the order of petaohms. While there is some sense in which a petaohm resistor conducts, the cases where that is relevant are so vanishingly rare that it is far more productive to the discussion to simply say it doesn't conduct.
This is one of those cases. Claiming that air is conductive is detrimental to the discussion at best.
You do realize that HTML is the old markup language, and BBCode and such are the new, invented ones, right? And furthermore, that /. is older than BBCode? The perfectly good standard is HTML, not BBCode.
The TV tax is also a silly silly idea, if you assume TV ownership is a good thing (whether that's the case is a different question). And since nearly everyone pays it anyway, it ends up being equivalent to a regressive general tax -- which means it would be better all around to simply take the money from the general fund and increase the general tax rate accordingly.
Why is this a tax on Internet access, rather than being drawn from the general fund? Net access is something that is good for people to have, so putting a tax on it is a bad thing, especially since it's a regressive tax (people with lower income will spend proportionally more of their income on net access, so proportionally more of their income goes to the tax).
Taxes on specific things, rather than broad taxes that go to the general fund, should be for one of two reasons. Either the tax should be intended to discourage something (whether that's an ethical reason I'll leave to others, but if society making such judgements is reasonable then the tax is reasonable), or the tax should be intended to internalize an internal cost. So taxes on carbon emissions and other polluting activities make sense (though imho tradable permits are better), because there is a normally external cost paid by society that should be shifted to the ones creating the problem. Internet access is neither of those things -- and public content is most certainly not an external cost.
XCOR Aerospace does this. Anyone who works on a vehicle, or manages someone who does, gets a ride in the vehicle. It's actually important that it be everyone, not just the high level people -- or, if you can't do everyone for logistical reasons, a randomly chosen sample. Managers can motivate the people they manage, but only within limits. It's not fair to ask the manager to trust his group's work if the rest of the group won't do the same.
I'm told this was also done for Vietnam War helicopter maintenence -- after major servicing, the chief mechanic rode on the checkout flight.
(Now, if only someone could show me how to embed nice links here... :) )
It's a web site. You use HTML. Why most forums insist on making up their own weird and varying markup systems when they're busy using a perfectly good one is completely beyond me, but somehow it's common enough that people expect it.
(You may have to change your posting options to "HTML formatted." You may then end up wanting to actually include formatting tags in your comments in order to get them to display properly.)
If they'd done this from the start, no one would be complaining. In Linux or UNIX, if a program wants elevated privileges, it requires user intervention. The result is that programs don't expect to have superuser privileges if they don't actually need them, and everyone is happy because the only things that have to be done as root are things you'd expect to require root access.
All this is happening in the chamber, not the nozzle. After the nozzle throat (the constriction before the expansion bell), the gas is supersonic and so can't really resonate (sound waves can't travel backward). The oscillations in question happen right at the injector face. Aerospike engines have a very different nozzle, but everything before the throat is fairly conventional -- so they'd exhibit the same problems, and measurement would be no easier.
People have built see-through chambers before, at varying levels of sophistication. This includes everything from liquid-cooled silica glass with LOX/LH2 engines to low-pressure oxygen/acrylic hybrids. The problem isn't seeing through the engine wall, it's seeing through the flame. That's what makes the photography they did so clever.
No, there's no angular momentum involved. The waves progress around the circumference, but the net average angular motion of the gas is zero. It's purely a wave phenomenon, and there are plenty of other resonant modes -- radial, tangential, etc. This just happens to be the mode they studied first.
The problem is one of Q factor. Resonant modes in an engine *will* be excited -- engines tend to have fairly distinctive character when you look at the FFT of the chamber pressure trace (a fancy way of saying engines have their own unique sound). If the resonance has a high Q factor, then the modest input power available at that frequency will build rapidly, and couple into the combustion process or injector and gain even more energy. If the Q factor is low, then it will only show up as a small peak above the white noise floor in the FFT, and there will never be a problem. It's the difference between a clock pendulum and a much cruder pendulum with a high friction bearing (say, a strip of wood with a rough hole in it hanging from a peg) -- a tiny energy input will cause the clock pendulum to make large swings, if presented at the correct frequency. But the crude pendulum will make tiny swings for a tiny energy input, whether you have the frequency perfect or not.
Sutton discusses that resonant mode (spinning tangential) briefly in Rocket Propulsion Elements (pg 353, 7th ed). There are plenty of more detailed discussions of combustion instability in general elsewhere in the literature. There are a variety of other resonant modes as well, this just happens to be the one the researchers looked at.
You can indeed add features to the chamber to de-tune it. It's anything but simple, though, and is mostly trial and error at present. Making the features not burn up is tricky; that part of why they're often added as part of the injector, since the injectors are cooled by the propellant flowing through them.
The second party has to accept the contract. The man being sued did not accept the contract, and no one is claiming he did. Since there is no dispute, there is no contract law question.
IANAL, but the EFF brief does a very good job of explaining why the CD was abandoned in the legal sense of California law. It meets the requirements of the abandonment law as far as I can see -- they gave up possession, and their actions demonstrated that they did not intend to regain possession at any time in the future. Is there any legal reason that isn't sufficient to constitute abandonment? UMG says it wasn't abandoned, but offer nothing beyond that assertion as evidence -- and the EFF presents case law that says that assertion is insufficient to create a question of fact. So why shouldn't I believe the EFF brief?
As I said, I'm not a lawyer, but I'm interested, assuming the legalese doesn't get overly dense. The EFF brief was quite readable.
It's not a contract case if there is no contract, and accepting a gift is not sufficient to create a contract.
Titanium may melt at 1900K, but rocket chambers operate in the realm of 2500-3500K. They have to be cooled, and copper is the material of choice for the same reason it makes good CPU heat sinks -- excellent thermal conductivity. Some older thrust chambers were made of steel (WAC Corporal, iirc), and it works at low chamber pressures (less heat flux), but it doesn't work as well and there are corrosion issues in storage. As performance increases and chamber pressures rise, metals other than copper look less and less appealing.
Some nozzles are uncooled in the aft portion (as the gas expands and accelerates, it cools down, so the environment gets easier to handle). The Kestrel engine used in the Falcon 1 upper stage, for example, has a radiatively cooled Niobium nozzle. Titanium has been used, but Niobium and a few others tend to perform better in that environment -- the combination of hot reactive gases is hard to handle.
The US is the same way, and the EFF brief explains all the gory details with plenty of references. Furthermore, gifts trigger the first sale doctrine -- again, there is plenty of precedent -- and stickers on the CDs are not enough to prevent the doctrine from taking effect.
First sale absolutely applies, as there is plenty of legal precedent that gifts count as sales for purposes of the first sale doctrine. The EFF brief has all the detailed arguments, and plenty of references. It's also quite readable, and quite thorough about dismantling UMG's arguments.