That can compensate for a simple phase shift, and is commonly used with eg motors. However, the power factor problems on CFLs arise because they rectify the AC waveform and draw current only at the peak voltages. That distortion is harder to correct. You can't just add a single inductor / capacitor, and you can't just run them in quadrature. You can add a more complex filter, but that gets expensive. It's probably cheaper to just build them with active PFC power supplies.
Firstly, realize that AC isn't nearly as simple as DC. You won't grasp it without at least a dash of calculus.
When we speak of volts or amps in AC, we usually mean the RMS average. The normal arithmetic average of an AC line is zero; it's a simple sine wave centered at zero. RMS means taking the square of the wave form, averaging that, and taking the square root of the result.
For simple resistors, everything is easy -- just apply Ohm's law and such with RMS values, and you're done. With anything more complicated, though, life is harder. RMS volts times RMS amps gives you "apparent power." If you take the instantaneous voltage times the instantaneous current, and graph that, you get a graph of instantaneous power to go with your current and voltage waveforms. If you average that (arithmetic, not RMS), you'll get real power. Real power is the energy absorbed by the device in question -- the amount of work it can do (plus inefficiencies), basically.
For a simple example, consider connecting a capacitor across an AC line. The voltage on it varies, and so there is current flow. But since it's an ideal capacitor, there is no power lost as heat. If you take V = sin(t), you'll find that I = C * cos(t) (since for a capacitor, I = C*dv/dt). Both sin and cos have an RMS average of sqrt(2). However, sin(t) * cos(t) = sin(2*t)/2 -- when this is positive, energy is being added to the capacitor; when negative, it is being removed. The average power usage consumed is zero (over the course of a full cycle), so the power factor is zero. Inductors behave similarly, except the phase shift is the opposite direction.
If you mix a resistive load with a reactive load (any capacitor or inductor), you get something in between -- the phase difference between voltage and current is more than zero but less than 90 deg. The power factor is somewhere between zero and one. This is the case for a normal motor, for example. (Some consideration will show why many AC motors have a capacitor attached to them.)
And of course, in the modern world, it's even more complicated -- nonlinear loads that create a distorted current or voltage waveform are weird. Just remember that real power = average(integral(V(t)*I(t)*dt)), and apparent power = RMS(V(t))*RMS(I(t)).
A single capacitor or inductor won't do very much about distortion. For something like a motor, that has a phase shift you want to correct, adding a capacitor works well. For distortion, you need a more complicated filter if you want good results. It would be simpler to add active PFC to the lights, I would guess.
It's not a simple phase shift. CFLs rectify the AC wave, meaning they only draw current on the peaks of the waveform. If you hook up a scope to your outlet (don't be an idiot; to all the non-EE types, don't try this if you don't know how) you can see it -- the waveform will have flatter tops than it should.
You can put complex bandpass / lowpass filters in the line that help a lot (by reflecting the distortion back at the load) but they get mode complicated and thus expensive.
There are lots of plausible answers, and most of them are annoyingly pricey. The best one I can think of is to just switch billing to VA instead of real watts, and let the customers sort it out.
Exactly. Sometimes kdawson manages to post what could have been a perfectly decent story (good topic, good article) with a horrible summary. Then no other editor will post about it because it's a dupe (I can dream, right?), and so we miss the whole/. discussion on the subject. What we really want is no kdawson, which means that those stories would be handled by a (somewhat more) competent editor.
Even if someone at the data center was involved, that doesn't mean they should take all the servers. Those servers don't belong to the data center; they belong to the people who own them, even if they're sitting in the data center.
So, the logical followup question TFA doesn't address, is do cortisol injections or pills on waking produce a change in the symptoms? In other words, is the cortisol level a cause of the differences in behavior / thought processes, a result of them, or is there a common underlying cause?
In the general case, if the comment is so obvious it wasn't worth making in the first place (or, especially, just repeats something in the summary / article), then it's redundant.
In this case, I agree, the moderation is silly. Hopefully it will be corrected in metamod.
In the case of contracts, the remedy is that the contract is void (details depend on context, IANAL, etc). We don't prosecute the minor in question for signing the contract. Similarly we shouldn't prosecute the children in question for taking the pictures.
Certainly there is potential for later regret, here. But, as with many stupid things kids do, the remedy is for the *parents* to do something, not the legal system. It seems this DA is forgetting that there are ways to impose consequences and teach lessons that would benefit these kids and don't involve him at all. The legal system is a heavy, blunt instrument; that's not what's called for here.
It works for a while. If you leave a tab unrefreshed in the background for an extended period (an hour or two? I haven't tested in detail) you'll get the weird behavior. I have "paused" turned on as well.
Being able to distinguish species is handy, because usually it's obvious where the boundary lies and it's useful to be able to talk about a specific species. However, there are plenty of cases that blur the line, and those are precisely the ones that show that macro and micro evolution are the same thing. Dogs are a good example -- there's lots of variation, and several different species by standard counting, but all domesticated dogs, wolves, dingos, etc can interbreed. In fact some different types of dingos (African vs Australian, iirc) are more genetically similar to each other than to domestic dogs, but have a closer common ancestor with domestic dogs than each other.
If you were trying to be scientific about it, I believe the generally used term is speciation, and it's used as a specific subset of evolution.
G and g don't refer to the same thing at all -- they're both related to the same force, but they're quite different. A better analogy (though still bad) might be to inheritance vs evolution. You can see that g and G aren't merely different aspects of the same thing because they have different units.
That leaves another problem. If I leave/. open for a long time, and then want to refresh it, I usually just click the big logo in the upper left. Now, if I do that, instead of reloading a popup appears telling me that it's paused. I can then click to unpause, and then click a third time to refresh! Obviously I could simply refresh the page instead of all this (which I usually do now, but habits die hard), but the behavior is still idiotic.
Was the subject abused or otherwise injured (psychologically or physically) by the photography? After all, child pornography laws are there to protect the children involved. If they took the pictures themselves, it's hard to make a case that they were injured.
It seems to me that if they're old enough to take responsibility for their actions in creating the pictures, and therefore old enough to be punished for them, then they're old enough to have given consent.
Sometimes, a test without context would be appropriate. In other cases, like this one, the context is sufficient to determine innocence without even looking at the pictures.
Whether you want to call it proof or disproof is a matter of semantics. However, the theory of evolution makes testable predictions. Those predictions have been tested repeatedly; sometimes they've been wrong and the theory has advanced (it's not the same as it was when Darwin proposed it), and often they've been quite accurate. The most dramatic examples are things like predictions that we would find intermediate fossils of a species in between two known fossils.
If you're looking for direct observational evidence of speciation (sometimes called macro evolution), it has been observed in the lab. One of the defining characteristics of E. Coli is the inability to metabolize citrate; this experiment demonstrated that E. Coli can evolve into something that can metabolize citrate.
In general, most modern scientific theories can't be tested in detail in the classroom; testing even Newton's version of gravity is a nontrivial experiment for a high school classroom. That doesn't mean it isn't worth study, though -- a discussion of the experiments is still useful.
Because trolling works -- it produces responses, and with those come page views and ad revenue. Trolls in the comments are bad because they piss people off and they leave; trolls on the front page are good because they piss people off and then they comment and view ads.
We learned about it as a failed theory, obviously. The fact that it was wrong doesn't mean it wasn't a valuable teaching tool for scientific principles. It's also an important part of the history of science.
The wording as described in the summary sounds fine in the abstract; I suspect the problem will come in the implementation.
As I see it, the problem with creationism and ID isn't that it's wrong, it's that it's untestable. Anything taught in the science classroom should be testable. There is a place for testable but wrong theories -- I remember learning about the aether, for example -- but things that make no testable predictions have no place. A discussion of how a popular theory (like the Ptolomeic theory of the solar system) gets disproved is quite valuable; if such a discussion was possible about creationism or ID it would have a place in the science classroom. But, as it makes no testable predictions, putting it in the same category as Aristotelean physics or Ptolomean astronomy is wrong.
I agree completely. They should spend a nontrivial amount of time in jail.
I also think it's likely that once they do, the point will have been quite thoroughly made, and that they're unlikely to commit the same crime (or a similar one) again. Sex offender registries are (ostensibly) for people who *can't* be rehabilitated -- people who are compelled to commit their crimes, regardless of any threat of punishment, no matter how clear that threat is. In other words, people who are still a danger to society even after their release. I don't think these criminals fit that description.
While it would be wonderfully poetic, that does not make it right. You won't stop people from trying to make examples of potential criminals by making examples of them. Much as it might be fun to do so, you won't convince them that the logic is flawed by using it on them.
Furthermore, sex offender registries are ostensibly for people for whom no reform is possible -- which is arguably the case for some sorts of offenders. However, it seems highly probably to me that a strong punishment would make these individuals unlikely to repeat their crime. They are guilty of criminally bad judgment, but there does not appear to be evidence that it was based on sexual needs that they will be unable to suppress.
I don't buy the argument that sex offender registries should exist, but even if you do, these people don't belong on them. They should still be punished rather harshly, though.
How, precisely, do petahertz EM waves differ from photons? Visible light is ~ 1PHz. All EM waves are photons; the only distinction is how obvious it is, which is an artifact of your observation technique and not the photon itself.
I'm sorry, did you have an alternative in mind? It's a hard problem; for all its flaws, HTML appears to be the best option available for this sort of thing. It takes a lot of hubris to loudly complain that you could have implemented it better when not only have you done nothing of the sort, but no one else has either.
Slashdot Mirror
That can compensate for a simple phase shift, and is commonly used with eg motors. However, the power factor problems on CFLs arise because they rectify the AC waveform and draw current only at the peak voltages. That distortion is harder to correct. You can't just add a single inductor / capacitor, and you can't just run them in quadrature. You can add a more complex filter, but that gets expensive. It's probably cheaper to just build them with active PFC power supplies.
Firstly, realize that AC isn't nearly as simple as DC. You won't grasp it without at least a dash of calculus.
When we speak of volts or amps in AC, we usually mean the RMS average. The normal arithmetic average of an AC line is zero; it's a simple sine wave centered at zero. RMS means taking the square of the wave form, averaging that, and taking the square root of the result.
For simple resistors, everything is easy -- just apply Ohm's law and such with RMS values, and you're done. With anything more complicated, though, life is harder. RMS volts times RMS amps gives you "apparent power." If you take the instantaneous voltage times the instantaneous current, and graph that, you get a graph of instantaneous power to go with your current and voltage waveforms. If you average that (arithmetic, not RMS), you'll get real power. Real power is the energy absorbed by the device in question -- the amount of work it can do (plus inefficiencies), basically.
For a simple example, consider connecting a capacitor across an AC line. The voltage on it varies, and so there is current flow. But since it's an ideal capacitor, there is no power lost as heat. If you take V = sin(t), you'll find that I = C * cos(t) (since for a capacitor, I = C*dv/dt). Both sin and cos have an RMS average of sqrt(2). However, sin(t) * cos(t) = sin(2*t)/2 -- when this is positive, energy is being added to the capacitor; when negative, it is being removed. The average power usage consumed is zero (over the course of a full cycle), so the power factor is zero. Inductors behave similarly, except the phase shift is the opposite direction.
If you mix a resistive load with a reactive load (any capacitor or inductor), you get something in between -- the phase difference between voltage and current is more than zero but less than 90 deg. The power factor is somewhere between zero and one. This is the case for a normal motor, for example. (Some consideration will show why many AC motors have a capacitor attached to them.)
And of course, in the modern world, it's even more complicated -- nonlinear loads that create a distorted current or voltage waveform are weird. Just remember that real power = average(integral(V(t)*I(t)*dt)), and apparent power = RMS(V(t))*RMS(I(t)).
A single capacitor or inductor won't do very much about distortion. For something like a motor, that has a phase shift you want to correct, adding a capacitor works well. For distortion, you need a more complicated filter if you want good results. It would be simpler to add active PFC to the lights, I would guess.
It's not a simple phase shift. CFLs rectify the AC wave, meaning they only draw current on the peaks of the waveform. If you hook up a scope to your outlet (don't be an idiot; to all the non-EE types, don't try this if you don't know how) you can see it -- the waveform will have flatter tops than it should.
You can put complex bandpass / lowpass filters in the line that help a lot (by reflecting the distortion back at the load) but they get mode complicated and thus expensive.
There are lots of plausible answers, and most of them are annoyingly pricey. The best one I can think of is to just switch billing to VA instead of real watts, and let the customers sort it out.
Perhaps they could whitelist a few more characters, then. All normal ltr-printing printable characters, for starters.
Exactly. Sometimes kdawson manages to post what could have been a perfectly decent story (good topic, good article) with a horrible summary. Then no other editor will post about it because it's a dupe (I can dream, right?), and so we miss the whole /. discussion on the subject. What we really want is no kdawson, which means that those stories would be handled by a (somewhat more) competent editor.
Even if someone at the data center was involved, that doesn't mean they should take all the servers. Those servers don't belong to the data center; they belong to the people who own them, even if they're sitting in the data center.
So, the logical followup question TFA doesn't address, is do cortisol injections or pills on waking produce a change in the symptoms? In other words, is the cortisol level a cause of the differences in behavior / thought processes, a result of them, or is there a common underlying cause?
In the general case, if the comment is so obvious it wasn't worth making in the first place (or, especially, just repeats something in the summary / article), then it's redundant.
In this case, I agree, the moderation is silly. Hopefully it will be corrected in metamod.
In the case of contracts, the remedy is that the contract is void (details depend on context, IANAL, etc). We don't prosecute the minor in question for signing the contract. Similarly we shouldn't prosecute the children in question for taking the pictures.
Certainly there is potential for later regret, here. But, as with many stupid things kids do, the remedy is for the *parents* to do something, not the legal system. It seems this DA is forgetting that there are ways to impose consequences and teach lessons that would benefit these kids and don't involve him at all. The legal system is a heavy, blunt instrument; that's not what's called for here.
It works for a while. If you leave a tab unrefreshed in the background for an extended period (an hour or two? I haven't tested in detail) you'll get the weird behavior. I have "paused" turned on as well.
Being able to distinguish species is handy, because usually it's obvious where the boundary lies and it's useful to be able to talk about a specific species. However, there are plenty of cases that blur the line, and those are precisely the ones that show that macro and micro evolution are the same thing. Dogs are a good example -- there's lots of variation, and several different species by standard counting, but all domesticated dogs, wolves, dingos, etc can interbreed. In fact some different types of dingos (African vs Australian, iirc) are more genetically similar to each other than to domestic dogs, but have a closer common ancestor with domestic dogs than each other.
If you were trying to be scientific about it, I believe the generally used term is speciation, and it's used as a specific subset of evolution.
G and g don't refer to the same thing at all -- they're both related to the same force, but they're quite different. A better analogy (though still bad) might be to inheritance vs evolution. You can see that g and G aren't merely different aspects of the same thing because they have different units.
Seconded. Please, for the love of the FSM, do this.
That leaves another problem. If I leave /. open for a long time, and then want to refresh it, I usually just click the big logo in the upper left. Now, if I do that, instead of reloading a popup appears telling me that it's paused. I can then click to unpause, and then click a third time to refresh! Obviously I could simply refresh the page instead of all this (which I usually do now, but habits die hard), but the behavior is still idiotic.
That is the only sane justification. The fact that your action would be illegal should be taken as an indictment of the law, not support of it.
Was the subject abused or otherwise injured (psychologically or physically) by the photography? After all, child pornography laws are there to protect the children involved. If they took the pictures themselves, it's hard to make a case that they were injured.
It seems to me that if they're old enough to take responsibility for their actions in creating the pictures, and therefore old enough to be punished for them, then they're old enough to have given consent.
Sometimes, a test without context would be appropriate. In other cases, like this one, the context is sufficient to determine innocence without even looking at the pictures.
Whether you want to call it proof or disproof is a matter of semantics. However, the theory of evolution makes testable predictions. Those predictions have been tested repeatedly; sometimes they've been wrong and the theory has advanced (it's not the same as it was when Darwin proposed it), and often they've been quite accurate. The most dramatic examples are things like predictions that we would find intermediate fossils of a species in between two known fossils.
If you're looking for direct observational evidence of speciation (sometimes called macro evolution), it has been observed in the lab. One of the defining characteristics of E. Coli is the inability to metabolize citrate; this experiment demonstrated that E. Coli can evolve into something that can metabolize citrate.
In general, most modern scientific theories can't be tested in detail in the classroom; testing even Newton's version of gravity is a nontrivial experiment for a high school classroom. That doesn't mean it isn't worth study, though -- a discussion of the experiments is still useful.
Because trolling works -- it produces responses, and with those come page views and ad revenue. Trolls in the comments are bad because they piss people off and they leave; trolls on the front page are good because they piss people off and then they comment and view ads.
We learned about it as a failed theory, obviously. The fact that it was wrong doesn't mean it wasn't a valuable teaching tool for scientific principles. It's also an important part of the history of science.
The wording as described in the summary sounds fine in the abstract; I suspect the problem will come in the implementation.
As I see it, the problem with creationism and ID isn't that it's wrong, it's that it's untestable. Anything taught in the science classroom should be testable. There is a place for testable but wrong theories -- I remember learning about the aether, for example -- but things that make no testable predictions have no place. A discussion of how a popular theory (like the Ptolomeic theory of the solar system) gets disproved is quite valuable; if such a discussion was possible about creationism or ID it would have a place in the science classroom. But, as it makes no testable predictions, putting it in the same category as Aristotelean physics or Ptolomean astronomy is wrong.
I agree completely. They should spend a nontrivial amount of time in jail.
I also think it's likely that once they do, the point will have been quite thoroughly made, and that they're unlikely to commit the same crime (or a similar one) again. Sex offender registries are (ostensibly) for people who *can't* be rehabilitated -- people who are compelled to commit their crimes, regardless of any threat of punishment, no matter how clear that threat is. In other words, people who are still a danger to society even after their release. I don't think these criminals fit that description.
While it would be wonderfully poetic, that does not make it right. You won't stop people from trying to make examples of potential criminals by making examples of them. Much as it might be fun to do so, you won't convince them that the logic is flawed by using it on them.
Or more simply, two wrongs do not make a right.
Furthermore, sex offender registries are ostensibly for people for whom no reform is possible -- which is arguably the case for some sorts of offenders. However, it seems highly probably to me that a strong punishment would make these individuals unlikely to repeat their crime. They are guilty of criminally bad judgment, but there does not appear to be evidence that it was based on sexual needs that they will be unable to suppress.
I don't buy the argument that sex offender registries should exist, but even if you do, these people don't belong on them. They should still be punished rather harshly, though.
How, precisely, do petahertz EM waves differ from photons? Visible light is ~ 1PHz. All EM waves are photons; the only distinction is how obvious it is, which is an artifact of your observation technique and not the photon itself.
I'm sorry, did you have an alternative in mind? It's a hard problem; for all its flaws, HTML appears to be the best option available for this sort of thing. It takes a lot of hubris to loudly complain that you could have implemented it better when not only have you done nothing of the sort, but no one else has either.