Why not just delete it right away? Commenting out code in version control just creates more changes.
How long back in the history one need to go back to recover the deleted code? While retrieving a deleted block, how many and which other changes needs will also need to be reverted for getting the functionality in a consistent state?
Mind you: the above questions are valid no matter if you choose to delete a commented code or just to let it there still commented. What may disappear from view you carelessly choose to delete it: any immediately visible sign that there was a different code performing the job somehow differently.
TFA's suggestions for what "YOU MIGHT ALSO LIKE" sound like juicy reading: "Pop Star Claims Sex With Ghost." "Curiosity: The Orgasm Gap." "Shrunken Head DNA Proves Horrific Folklore True." Now that's internets you can wrap fish in!
Wha...? I'm not seeing them!? Aah... it may be the tracking cookies on your browser that bring those suggestions.
I would hate to see the other units disappear as well but, as far as I'm concerned, someone should always be able to order a pint of ale. Any metric twaddle that threatens that should be thrown out with the other trash.
Sorry, Dave, ale's getting slightly better with metric. If you order "half-an-L" it will be approx one shot more of ale.
Tradeshows are basically just scams run by the people who operate them. Companies spend a lot of money and time and energy to be at them for no real reason... I just dont give a shit.
...
I get so much god damn advertising, sales pitches and annoying slogans thrown at me in my life everyday the last thing I want is to subject myself to more of it in a giant room of high concentration sales people. I went to e3 awhile back 3 years in a row and god damn, the was enough to last me my whole life.
All good and dandy, dude, but... are you somehow saying the free t-shirts you've got in 3 years at e3 are enough to last you an entire life?
Practically speaking, if you are operating in a regime where multiphoton absorption is not relevant, you won't be exciting anything significant to higher states, which is quite possible in some laser setups.
Practically speaking, one doesn't need the "negative temperature" concept to design/built/operate a laser.
From a more theoretical standpoint, you can just consider the populations in the states desired and treat the rest as the external environment, if done carefully.
Yes, but in this case, "negative temperature" becomes a theoretical construct. At most, something to make the theoretical formalism easier to operate (e.g. for example, involving complex numbers in singal processing or quaternions in dealing with 3D transformations).
Otherwise, there would be no negative temperature systems anywhere, as any experiment if you add enough energy, the whole apparatus would be excited into a state of plasma and there would be no upper bound on energy in any system. All that is really matters is that statistical mechanical models using negative energy are relevant to this systems as being used.
Agreed. But you need to admit the fact that "negative temperature" is rather a theoretical artefact - it's not that one would use a thermometer set (a "classical thermodynamics" device) in contact with system to probe a "negative absolute temperature".
Negative temperatures do not violate the third law of thermodynamics, and can still be considered a thermodynamic system. Moving the temperature of a system toward absolute zero still causes the entropy to approach a constant value, whether you do so from the negative or positive side.
That's what I said: arrange for some strange meanings of the temperature scale - this means you are dropping the "classical" view of the temperature ("a measure of atomic/molecular kinetic energy") and replace it with a "generalized" meaning, extended to be self-consistent across the positive and negative side of the scale. But in doing so, one should abandon any attempt to use the older/"classical" meaning on the extended side and embrace the new definition/concepts the extension requires.
One does not need to involve QM (or Dalai Lama) into the picture to explain the extended model to a layman - that's was my point in responding to the OP. Granted, statistical mechanics (with a pinch of QM) would describe more exact what exactly happens - however the thermodynamics approach is still sufficient in this case.
Nope, you're wrong. Lasing higher excited states are at least as many as the ground states but usually are in higher number than the ground states (e.g. He-Ne laser - the lasing medium is He - the ground state is 1s, the lasing excited states are 2s and 3s - thus twice as many as the ground state). The only requirement for lasing is the higher states be meta-stable - last long enough for storing the energy in a population inversion - but there are an infinite number of states with higher energy (even if not necessary all of them useful for lasing) - for the chosen example: the "s" states in He does not stop at 3s, there are an infinite number of them.
No, lasers are not an example of negative temperature.
For a thermodynamic system, zero temperature is when you can't vary (as in... decrease it) the internal energy of the system, the order of system is maximum. For a "negative temperature system" (no longer a thermodynamic one), this translates into "after a point, one can no longer pump energy into the system, the order has reach the maximum". This does not happen into a laser.
If 'nerds' had paid any attention to their thermodynamics/statistical mechanics class they would have already know all this and we would have been spared two frivolous posts in the front page.
Why are you being so negative?
Actually, s/he's beyond infinitely positive.
(as in: correctly stating the problem is, most of the time, a necessary step to solve it. As in: yes, there is a possibility to solve a problem without knowing about it, but what's the probability?)
Systems with an upper bound in energy don’t want to be in that highest energy state.
Sigh...
Well, I concur, anthropomorphising these systems is a big problem.
You see: the matter and energy (no matter their colour - dark/white, orientation - up/down, flavour/charm/strangeness, etc) are freer and have more self-determination than any human being will ever have. They only obey the laws of physics, while the human beings need to obey heaps of others (e.g. did you ever see an electron being groped by TSA agents when passing through a semiconductor gate?).
Anthropomorphizing is degrading for physical entities and, for their sake, need to stop. Join the movement for upholding the inalienable rights of energy and matter before is too late!
This doesn't really help. I pondered this for a while the other day when I read that first and gave up trying to wrap my head around it. I was always under the impression that 0 kelvin (absolute 0) meant a state at which there was no movement at the atomic/subatomic level. It would seem as though to reach a negative temperature, one would have to slow a substances particles to less than 0 movement)
1. in the classical thermodynamics and forcing the terms, the temperature is defined as "the measure of willingness of a system to un-aided transfer energy to another system". If, when set in contact, two system do not exchange energy, they have the same temperature. If one system spontaneously (i.e. not aided, without intervention) transfer energy to a second, then the temperature of the first one is higher than the second one
2. you need to adjust your view on what "absolute 0 temperature" means: it is not that the total energy of the system is zero (thus no movement), but the system tends towards a constant energy. For thermodynamic systems (most of the systems in the nature), this constant energy is the minimum the system can reach. Also, in this state, the order of the system is maximum (the entropy, as a measure of disorder, is minimum) Bottom line: to reach absolute zero temperature, one needs to extract energy from a thermodynamic system; for a thermodynamic system, a zero temperature means a point where no energy can be extracted any more because the order of the system is maximum (entropy is minimum)
3. special arrangements can be made so that some system will have a higher order at higher energies (the system is not a thermodynamic one any more). For such systems, to reach a point where the order is maximum (and the energy of the system becomes constant), one needs to pump energy into the system. Reaching this maximum will make the system "unwilling" to absorb any more energy - and this is a mandatory condition for the current definition of "systems with negative temperature" (this is why lasers are not good examples of such systems).
Now, as such a system the notion of "temperature" does not apply sensu stricto any more, because the system is no longer a thermodynamic one. If set in contact with another system, the "negative temperature" one will gladly transfer energy at the cost of increasing the disorder of the system. It is the third law of thermodynamics such a system violates (thus, no longer being a thermodynamic system).
But, like the mathematicians, one may try to expand the definition of a function domain and force the definition of the temperature as a relation to the entropy (thus enforce the validity of the third law). One can do that only when sacrificing at least one of other principles of thermodynamics or arrange for some strange meanings of the temperature scale, in which "negative temperatures" a actually higher than +infinity K.
Trying to think of negative temperatures as "below 0K" is invalid, in fact "negative absolute temperatures" are hotter than anybody can imagine.
The internet would still be a bunch of news groups if it wasn't for advertising:...
Like Wikipedia, you mean?
How many people would pay for an internet connection just to read Wikipedia? How many Wikipedia authors would pay for their internet connection to write articles, if almost no one had the ability to read it?
The internet needs a critical mass of people to make wikipedia viable, and almost all of the content that makes people decide their connection is worth paying for is ad supported. Like the site you are reading right now.
I'm old enough to fondly remember the Internet pre- and at the peak time of Usenet (the "September that never ended" moment). I found that Internet highly more diverse and interesting (beating/. pants down - no disrespect for the host). Damn you forever, Canter & Siegel!
(the kids these days... know nothing better but cocky, you know?).
That being said, do you know what all lazy people have in common? Being fucking lazy.
Bottom line is when it takes longer to type the question on Slashdot than it does to find the answer in Google, you're not only doing it wrong, but you have no right calling yourself a nerd.
Gosh, buddy... you let common sense slipping into/. . This does need to be corrected... so let's build a theory and draw a conclusion that is in no logical relation with it... bonus points if the conclusion is emotionally loaded and involves building a strawman!
That a look on the nickname of the OP (Serenissima not Serenissimus). Together with the mention of "so I could get some cleaning done" best chances that's a she - and I'm not implying the cleaning is done by women only, but I surmise women are more likely to mention it to establish a context for the post (male nerds wouldn't think of it as a relevant information)
Now, we may have a person:
1. which know what/. and posting on/. are
2. does cleaning (mind you: this may be as a reasonable explanation for not turning to Google as laziness would be. Not for the lack of time - Google is faster - but do I need to ask you what would you prefer: posting on/. or cleaning? Speaking for myself, I'm procrastinating from ironing my shirts for the next week as I'm posting this on/.)
3. has a small kid (which, highly probable, indicates sex in the near past)
4. likely to be a woman.
Of course, the above doesn't describe a very typical nerd (points 2 and 3 being highly atypical), but... hey... why would you try to quench cultural diversity on/.? I thought nerds are quite liberally minded.
No. people need to know they are being lazy, and being nice hasn't been working.
Working for what (i.e. what purpose do you target)? 'Cause not all the nerds share the same purposes, moral or ethical values (and it's is still OK... less boring, you see?)
E.g. if it is the opportunity of jerks to show themselves informative (which I can accept as a passable purpose), it seems it's working quite well.
That's fine if you're redistributing old desktops to set up a lab for kids to type up term papers or something but supercomputers are supposed to be cutting edge.
And... why don't you trust them to break the supercomputer in such way that the pieces will all have cutting edges?
Slashdot Mirror
Why not just delete it right away? Commenting out code in version control just creates more changes.
How long back in the history one need to go back to recover the deleted code? While retrieving a deleted block, how many and which other changes needs will also need to be reverted for getting the functionality in a consistent state ?
Mind you: the above questions are valid no matter if you choose to delete a commented code or just to let it there still commented. What may disappear from view you carelessly choose to delete it: any immediately visible sign that there was a different code performing the job somehow differently.
We are in the context of US switching to metric, aren't we? And if so, we are speaking about the US pint, isn't it?
TFA's suggestions for what "YOU MIGHT ALSO LIKE" sound like juicy reading: "Pop Star Claims Sex With Ghost." "Curiosity: The Orgasm Gap." "Shrunken Head DNA Proves Horrific Folklore True." Now that's internets you can wrap fish in!
Wha...? I'm not seeing them!?
Aah... it may be the tracking cookies on your browser that bring those suggestions.
or the amount of land an oxen ploughs in a day
'scuse me, mate, how many bullocks to an oxen?
I would hate to see the other units disappear as well but, as far as I'm concerned, someone should always be able to order a pint of ale. Any metric twaddle that threatens that should be thrown out with the other trash.
Sorry, Dave, ale's getting slightly better with metric.
If you order "half-an-L" it will be approx one shot more of ale.
Tradeshows are basically just scams run by the people who operate them. Companies spend a lot of money and time and energy to be at them for no real reason... I just dont give a shit.
...
I get so much god damn advertising, sales pitches and annoying slogans thrown at me in my life everyday the last thing I want is to subject myself to more of it in a giant room of high concentration sales people. I went to e3 awhile back 3 years in a row and god damn, the was enough to last me my whole life.
All good and dandy, dude, but... are you somehow saying the free t-shirts you've got in 3 years at e3 are enough to last you an entire life?
Practically speaking, if you are operating in a regime where multiphoton absorption is not relevant, you won't be exciting anything significant to higher states, which is quite possible in some laser setups.
Practically speaking, one doesn't need the "negative temperature" concept to design/built/operate a laser.
From a more theoretical standpoint, you can just consider the populations in the states desired and treat the rest as the external environment, if done carefully.
Yes, but in this case, "negative temperature" becomes a theoretical construct. At most, something to make the theoretical formalism easier to operate (e.g. for example, involving complex numbers in singal processing or quaternions in dealing with 3D transformations).
Otherwise, there would be no negative temperature systems anywhere, as any experiment if you add enough energy, the whole apparatus would be excited into a state of plasma and there would be no upper bound on energy in any system. All that is really matters is that statistical mechanical models using negative energy are relevant to this systems as being used.
Agreed. But you need to admit the fact that "negative temperature" is rather a theoretical artefact - it's not that one would use a thermometer set (a "classical thermodynamics" device) in contact with system to probe a "negative absolute temperature".
Negative temperatures do not violate the third law of thermodynamics, and can still be considered a thermodynamic system. Moving the temperature of a system toward absolute zero still causes the entropy to approach a constant value, whether you do so from the negative or positive side.
That's what I said: arrange for some strange meanings of the temperature scale - this means you are dropping the "classical" view of the temperature ("a measure of atomic/molecular kinetic energy") and replace it with a "generalized" meaning, extended to be self-consistent across the positive and negative side of the scale. But in doing so, one should abandon any attempt to use the older/"classical" meaning on the extended side and embrace the new definition/concepts the extension requires.
One does not need to involve QM (or Dalai Lama) into the picture to explain the extended model to a layman - that's was my point in responding to the OP. Granted, statistical mechanics (with a pinch of QM) would describe more exact what exactly happens - however the thermodynamics approach is still sufficient in this case.
Nope, you're wrong. Lasing higher excited states are at least as many as the ground states but usually are in higher number than the ground states (e.g. He-Ne laser - the lasing medium is He - the ground state is 1s, the lasing excited states are 2s and 3s - thus twice as many as the ground state). The only requirement for lasing is the higher states be meta-stable - last long enough for storing the energy in a population inversion - but there are an infinite number of states with higher energy (even if not necessary all of them useful for lasing) - for the chosen example: the "s" states in He does not stop at 3s, there are an infinite number of them.
Plenty of lasers around.
No, lasers are not an example of negative temperature.
For a thermodynamic system, zero temperature is when you can't vary (as in... decrease it) the internal energy of the system, the order of system is maximum.
For a "negative temperature system" (no longer a thermodynamic one), this translates into "after a point, one can no longer pump energy into the system, the order has reach the maximum". This does not happen into a laser.
If 'nerds' had paid any attention to their thermodynamics/statistical mechanics class they would have already know all this and we would have been spared two frivolous posts in the front page.
Why are you being so negative?
Actually, s/he's beyond infinitely positive.
(as in: correctly stating the problem is, most of the time, a necessary step to solve it. As in: yes, there is a possibility to solve a problem without knowing about it, but what's the probability?)
Systems with an upper bound in energy don’t want to be in that highest energy state.
Sigh...
Well, I concur, anthropomorphising these systems is a big problem.
You see: the matter and energy (no matter their colour - dark/white, orientation - up/down, flavour/charm/strangeness, etc) are freer and have more self-determination than any human being will ever have. They only obey the laws of physics, while the human beings need to obey heaps of others (e.g. did you ever see an electron being groped by TSA agents when passing through a semiconductor gate?).
Anthropomorphizing is degrading for physical entities and, for their sake, need to stop. Join the movement for upholding the inalienable rights of energy and matter before is too late!
This doesn't really help. I pondered this for a while the other day when I read that first and gave up trying to wrap my head around it. I was always under the impression that 0 kelvin (absolute 0) meant a state at which there was no movement at the atomic/subatomic level. It would seem as though to reach a negative temperature, one would have to slow a substances particles to less than 0 movement)
My understanding on negative temperature without requiring QM:
1. in the classical thermodynamics and forcing the terms, the temperature is defined as "the measure of willingness of a system to un-aided transfer energy to another system". If, when set in contact, two system do not exchange energy, they have the same temperature. If one system spontaneously (i.e. not aided, without intervention) transfer energy to a second, then the temperature of the first one is higher than the second one
2. you need to adjust your view on what "absolute 0 temperature" means: it is not that the total energy of the system is zero (thus no movement), but the system tends towards a constant energy. For thermodynamic systems (most of the systems in the nature), this constant energy is the minimum the system can reach. Also, in this state, the order of the system is maximum (the entropy, as a measure of disorder, is minimum)
Bottom line: to reach absolute zero temperature, one needs to extract energy from a thermodynamic system; for a thermodynamic system, a zero temperature means a point where no energy can be extracted any more because the order of the system is maximum (entropy is minimum)
3. special arrangements can be made so that some system will have a higher order at higher energies (the system is not a thermodynamic one any more). For such systems, to reach a point where the order is maximum (and the energy of the system becomes constant), one needs to pump energy into the system. Reaching this maximum will make the system "unwilling" to absorb any more energy - and this is a mandatory condition for the current definition of "systems with negative temperature" (this is why lasers are not good examples of such systems).
Now, as such a system the notion of "temperature" does not apply sensu stricto any more, because the system is no longer a thermodynamic one. If set in contact with another system, the "negative temperature" one will gladly transfer energy at the cost of increasing the disorder of the system. It is the third law of thermodynamics such a system violates (thus, no longer being a thermodynamic system).
But, like the mathematicians, one may try to expand the definition of a function domain and force the definition of the temperature as a relation to the entropy (thus enforce the validity of the third law).
One can do that only when sacrificing at least one of other principles of thermodynamics or arrange for some strange meanings of the temperature scale, in which "negative temperatures" a actually higher than +infinity K .
Trying to think of negative temperatures as "below 0K" is invalid, in fact "negative absolute temperatures" are hotter than anybody can imagine.
The internet would still be a bunch of news groups if it wasn't for advertising: ...
Like Wikipedia, you mean?
How many people would pay for an internet connection just to read Wikipedia? How many Wikipedia authors would pay for their internet connection to write articles, if almost no one had the ability to read it?
The internet needs a critical mass of people to make wikipedia viable, and almost all of the content that makes people decide their connection is worth paying for is ad supported. Like the site you are reading right now.
I'm old enough to fondly remember the Internet pre- and at the peak time of Usenet (the "September that never ended" moment). I found that Internet highly more diverse and interesting (beating /. pants down - no disrespect for the host). Damn you forever, Canter & Siegel!
(the kids these days... know nothing better but cocky, you know?).
That being said, do you know what all lazy people have in common? Being fucking lazy.
Bottom line is when it takes longer to type the question on Slashdot than it does to find the answer in Google, you're not only doing it wrong, but you have no right calling yourself a nerd.
Gosh, buddy... you let common sense slipping into /. . This does need to be corrected... so let's build a theory and draw a conclusion that is in no logical relation with it... bonus points if the conclusion is emotionally loaded and involves building a strawman!
That a look on the nickname of the OP (Serenissima not Serenissimus). Together with the mention of "so I could get some cleaning done" best chances that's a she - and I'm not implying the cleaning is done by women only, but I surmise women are more likely to mention it to establish a context for the post (male nerds wouldn't think of it as a relevant information)
Now, we may have a person: /. and posting on /. are
/. or cleaning? Speaking for myself, I'm procrastinating from ironing my shirts for the next week as I'm posting this on /.)
1. which know what
2. does cleaning (mind you: this may be as a reasonable explanation for not turning to Google as laziness would be. Not for the lack of time - Google is faster - but do I need to ask you what would you prefer: posting on
3. has a small kid (which, highly probable, indicates sex in the near past)
4. likely to be a woman.
Of course, the above doesn't describe a very typical nerd (points 2 and 3 being highly atypical), but... hey... why would you try to quench cultural diversity on /.? I thought nerds are quite liberally minded.
(ducks)
Bin Laden... scaring US airports with a toothbrush since 2001. Death is not an impediment.
No. people need to know they are being lazy, and being nice hasn't been working.
Working for what (i.e. what purpose do you target)? 'Cause not all the nerds share the same purposes, moral or ethical values (and it's is still OK... less boring, you see?)
E.g. if it is the opportunity of jerks to show themselves informative (which I can accept as a passable purpose), it seems it's working quite well.
I fail to see the downside.
replace ad's with porn, and you can see the slippery slope.
The down side of the porn becoming slippery? Well, that's an advantage so big it get's me all wet.
(ducks)
Frankly this is a little ignorant. The internet is not for any one thing.
Yes, it is
The internet would still be a bunch of news groups if it wasn't for advertising: ...
Like Wikipedia, you mean?
advertising spurred people to create and advance content
Ah, yes, we wouldn't have FaeceBook without advertising.
Probably, but it still doesn't make much sense.
C'mon, it's /. , what do you expect?
Nerds need to be exact, not necessarily to make sense... (otherwise they wouldn't be different enough from non-nerds to justify a distinctive term)
That's fine if you're redistributing old desktops to set up a lab for kids to type up term papers or something but supercomputers are supposed to be cutting edge.
And... why don't you trust them to break the supercomputer in such way that the pieces will all have cutting edges?
Is "Those new Mexicans are cunning." more accurate?
Intermission? Why? Bring back Megaupload instead!
You do know that you have to have a license in order to carry concealed in almost every state in the Union, right?
Which union? The Red one or the Blue one? (they look to me as quite far apart, as in "polarized")