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Thread: Negative Energy Proven? Hoax?

  1. #1 Negative Energy Proven? Hoax? 
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    Atoms at negative absolute temperature: The hottest systems in the world

    From what I've gathered, it's basically saying that if you cool a gas down enough (to below 0 K) the atoms gain energy! This violates the conservation of energy law, does anyone know if such a breakthrough has been replicated? I see no April 1st mentioned anywhere in the article to give it the benefit of the doubt. How are the atoms gaining energy if they're having energy taken away from them? Where is this energy coming from?

    I smell a hoax.


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  3. #2  
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    1) What's this got to do with "negative energy"?

    Quote Originally Posted by FrankBaker View Post
    From what I've gathered, it's basically saying that if you cool a gas down enough (to below 0 K)
    Read it again.
    "one cannot go below zero".
    "the gas is not colder than zero Kelvin, but hotter".

    the atoms gain energy!
    That's not what it says.

    This violates the conservation of energy law
    No it doesn't: "This does not mean that the law of energy conservation is violated".

    I see no April 1st mentioned anywhere in the article to give it the benefit of the doubt. ... I smell a hoax.
    Perhaps if you read the article (and maybe even Googled a bit) before posting you'd be less of a tedious troll.
    Start here. Or here.


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    No, I read the article properly. It says that when the atoms are below 0 K, they become hotter than infinitely positive temperature, even at below zero K.

    This would mean there is an increase in energy as the temperature goes below 0 K = or ''negative energy''

    ''Temperature'' is the kinetic vibration of atoms. It says the atoms become infinitely hot when cooled below zero K. ''Hot'' means = lots of energy.

    It's basically saying you could start a campfire if you had a laser gun which cooled the material to below zero K and pointed it to a log.
    The laws of physics have flew out the window. I'm calling hoax. I've reported the article, obviously made up to annoy people who enjoy real physics. hopefully it gets removed !
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    Speaking as a layman, this is intriguing. The title seems a little misleading though, we aleady have an expectation of the concept of negative temperature and this discovery is inconsistent with those expectations.

    I would have chosen different terminology to below absolute zero. It seems more like a, um... different thing.
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  6. #5  
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    Quote Originally Posted by FrankBaker View Post
    No, I read the article properly. It says that when the atoms are below 0 K, they become hotter than infinitely positive temperature, even at below zero K.
    No it doesn't.
    It SPECIFICALLY states (and I actually quoted the relevant words): "one cannot go below zero" and "the gas is not colder than zero Kelvin, but hotter".

    It says the atoms become infinitely hot when cooled below zero K.
    No it doesn't. See my previous comment. or read the article.

    It's basically saying you could start a campfire if you had a laser gun which cooled the material to below zero K and pointed it to a log.
    Bullshit.
    Read the f*cking article: "not possible in water or any other natural system with moving particles".

    The laws of physics have flew out the window.
    Also bullshit.

    I'm calling hoax!
    You don't know enough physics to make that call.
    (And have, in fact, ignored or dismissed the evidence that you're wrong).
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  7. #6  
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    Quote Originally Posted by FrankBaker View Post
    No, I read the article properly.
    I don't think so, because you keep making statements that are specifically contradicted in the article. For example, the article explicitly states that "This does not mean that the law of energy conservation is violated."

    The laws of physics have flew out the window.
    They haven't. The fact that the researchers used the laws of physics to design the experiment, and that they observed the result that was predicted on that basis, rather contradicts your premature conclusion.

    I'm calling hoax.
    You can call whatever you want, but anyone who reads the article carefully will come to a different conclusion.

    I've reported the article, obviously made up to annoy people who enjoy real physics. hopefully it gets removed !
    That's just silly. I recommend re-reading the article, this time with much greater care.
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    On second thought, different people have different expectations when it comes to words technically meaning something different to "common" perception (like the word "theory") so I'm most likely just being ignorant and the phrase "negative absolute temperature" is perfectly accurate to use in this context.
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    So if a physicist says that it isn't being violated, that means it isn't? No, anyone can say anything. I've re-read the article 3 times, my jaw still drops each time. It sounds like a complete joke!
    How can a gas negative in temperature also be hotter than infinite positive temperature? How can cooling something make it gain energy (temperature?)
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    Quote Originally Posted by FrankBaker View Post
    So if a physicist says that it isn't being violated, that means it isn't?
    No. If if it's not being violated THAT means it's not being violated.

    I've re-read the article 3 times
    And yet (several times) you have stated the exact opposite of what the article says.
    So either you haven't read it, you haven't understood it or you're stupid or lying.

    How can a gas negative in temperature be hotter than positive temperature? How can cooling something make it gain energy (temperature?)
    Did you bother to look at the links provided?
    (I don't know why I ask, since you haven't read/ understood the article).
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  11. #10  
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    The molecules are "saturated" with kinetic energy, so much so that they're stuck at the top of their potential energy limit.

    They're not "colder than cold" in the conventional sense, the temperature appears to be negative in the sense of mathematics rather than physics? Of course, I don't fully understand it myself, but then I'm not qualified.
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    Let's go through this.

    ''"Yet the gas is not colder than zero Kelvin, but hotter. It is even hotter than at any positive temperature – the temperature scale simply does not end at infinity, but jumps to negative values instead."

    But a negative value would mean the gas is colder than zero kelvin, it would be negative kelvin.

    ''The negative temperature state in their experiment is indeed just as stable as a positive temperature state. "That way, we have created the first negative absolute temperature state for moving particles," he adds.''

    ''Matter at negative absolute temperature leads to a whole bunch of astounding consequences: With its help, one could create heat engines with an efficiency above 100%. This does not mean that the law of energy conservation is violated. Instead, the machine could not only absorb energy from the hotter substance, but, in contrast to the usual case, also from the colder. ''

    How? Colder means less energy.

    ''The work performed by the engine could therefore be larger than the energy taken from the hotter substance alone.''

    Now it's saying a colder substance has more energy than the hotter substance.
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    Quote Originally Posted by FrankBaker View Post
    Blah. Blahblahblah blah. Blah
    And that, boys and girls, is how you end up if you don't bother to read the article properly and ignore all the links (or the existence of Google).
    That's what happens if you don't understand something and are too lazy/ stupid to read up and learn. (Or even listen to what's being said).
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    Think of antimatter, it's not simply "space" that's emptier than empty. Antimatter is stuff, just "negative".

    Negative absolute temperature can be thought of in a similar way to antimatter, I guess? It's not colder than zero, it's just "negative".
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  15. #14  
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    From my first link:
    That a system at negative temperature is hotter than any system at positive temperature is paradoxical if absolute temperature is interpreted as an average kinetic energy of the system. The paradox is resolved by understanding temperature through its more rigorous definition as the tradeoff between energy and entropy, with the reciprocal of the temperature, thermodynamic beta, as the more fundamental quantity. Systems with a positive temperature will increase in entropy as one adds energy to the system. Systems with a negative temperature will decrease in entropy as one adds energy to the system.
    If "FrankBaker" had at all bothered to read that link then we wouldn't have reached this many posts with the tedious troll still posting crap.
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  16. #15  
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    What are the odds that he will use his ignorance and lack of understanding to twist this to support his ludicrous spontaneous human combustions fetish?
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  17. #16  
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    So it's like the "-3rd" law of thermodynamics?
    Last edited by Daecon; May 28th, 2014 at 03:56 AM. Reason: Wrong law
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    When in doubt refer to the FAQ by the research group in question: Quantum Munich*:*Negative Absolute Temperature

    From the faq:
    Is your system really colder than zero Kelvin?

    No! Nothing can be colder than absolute zero (0K)!
    Negative absolute temperatures (or negative Kelvin temperatures) are hotter than all positive temperatures - even hotter than infinite temperature.
    As is often the case with technical subjects we are presented with an unfortunate choice: an explanation that is accurate but incomprehensible, or comprehensible but wrong.
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  19. #18  
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    Quote Originally Posted by FrankBaker View Post
    Atoms at negative absolute temperature: The hottest systems in the world

    From what I've gathered, it's basically saying that if you cool a gas down enough (to below 0 K) the atoms gain energy! This violates the conservation of energy law, does anyone know if such a breakthrough has been replicated? I see no April 1st mentioned anywhere in the article to give it the benefit of the doubt. How are the atoms gaining energy if they're having energy taken away from them? Where is this energy coming from?

    I smell a hoax.
    EVERYONE, this has been done already.

    For a start it is NOT negative energy. It is so-called "negative temperature": quite a different concept.

    Secondly, describing the phenomenon this way is just a journalistic device to make headlines. This is just a population inversion, i.e. an unstable, or at best metastable, energy distribution that does not follow the Maxwell Boltzmann one. As any physicist can tell you, a distribution that does not follow this is out of equilibrium and therefore does not have a defined temperature in the first place.

    Thirdly, "FrankBaker" is not interested in physics. His object is to annoy scientists. You can expect him to try to keep this discussion going for a long time by (a) being deliberately obtuse and /or (b) by periodically injecting some new bit of nonsense when the argument flags.

    This thread will go nowhere useful.
    Last edited by exchemist; May 28th, 2014 at 05:08 AM.
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  20. #19  
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    May be a new tack, viz the old Gerry Adams "Big Lie" trick of accusing your opponent of what you yourself are guilty of, as in, "The Brotush Armeaigh is a bonch of morrdorous bastards" - but in this case a "hoax".

    For this individual I suspect SHC is a means to the same end as as exploding thymus glands etc., viz. an attack on science and scientists for the purpose of amusement. We'll see.

    Maybe these interventions will put him off. If not, perhaps we can all at least get some fun out of it by treating this as a natural phenomenon, to be studied scientifically.
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  21. #20  
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    Quote Originally Posted by exchemist View Post
    May be a new tack, viz the old Gerry Adams "Big Lie" trick of accusing your opponent of what you yourself are guilty of, as in, "The Brotush Armeaigh is a bonch of morrdorous bastards" - but in this case a "hoax".

    For this individual I suspect SHC is a means to the same end as as exploding thymus glands etc., viz. an attack on science and scientists for the purpose of amusement. We'll see.

    Maybe these interventions will put him off. If not, perhaps we can all at least get some fun out of it by treating this as a natural phenomenon, to be studied scientifically.
    True, the nonsense threads started by Frank/Melissa/Lady Gaia/any other sock puppets are, in the main, too dumb to be genuine...
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    You're not to the point.


    Negative temperature is HOTTER than infinite + temperature? How is that possible? If you could cool something down gradually, it gets colder, no? So if I had a machine which cooled a gas gradually from say, 5 kelvin to -1000 kelvin, eventually I'd get a gas that became hotter as I tried to cool it as if I were heating it with a flame?
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    Quote Originally Posted by FrankBaker View Post
    You're not to the point.


    Negative temperature is HOTTER than infinite + temperature? How is that possible? If you could cool something down gradually, it gets colder, no? So if I had a machine which cooled a gas gradually from say, 5 kelvin to -1000 kelvin, eventually I'd get a gas that became hotter as I tried to cool it as if I were heating it with a flame?
    Well I tried to explain it as best I could from how I understood it, which parts of my comments was I not clear on?
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  24. #23  
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    Frank read the links provided (and post 18) and stop being a dumb troll.
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    Quote Originally Posted by FrankBaker View Post
    So if I had a machine which cooled a gas gradually from say, 5 kelvin to -1000 kelvin
    Not possible.
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    Quote Originally Posted by Daecon View Post
    Quote Originally Posted by FrankBaker View Post
    You're not to the point.


    Negative temperature is HOTTER than infinite + temperature? How is that possible? If you could cool something down gradually, it gets colder, no? So if I had a machine which cooled a gas gradually from say, 5 kelvin to -1000 kelvin, eventually I'd get a gas that became hotter as I tried to cool it as if I were heating it with a flame?
    Well I tried to explain it as best I could from how I understood it, which parts of my comments was I not clear on?
    I suspect nothing is clear to him.

    Frank, your knowledge is clearly lacking here. I can't understand how someone who knows he is not qualified can still proceed to call BS on science topic he clearly doesn't understand. I suggest letting go of preconceptions and reading up on the experiment and physics around it.
    Disclaimer: I do not declare myself to be an expert on ANY subject. If I state something as fact that is obviously wrong, please don't hesitate to correct me. I welcome such corrections in an attempt to be as truthful and accurate as possible.

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  27. #26  
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    Quote Originally Posted by PhDemon View Post
    .......too dumb to be genuine...
    There's a law for that....Poe's law - Wikipedia, the free encyclopedia
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    Fixin' shit that ain't broke.
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  28. #27  
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    Quote Originally Posted by KALSTER View Post
    Quote Originally Posted by Daecon View Post
    Quote Originally Posted by FrankBaker View Post
    You're not to the point.


    Negative temperature is HOTTER than infinite + temperature? How is that possible? If you could cool something down gradually, it gets colder, no? So if I had a machine which cooled a gas gradually from say, 5 kelvin to -1000 kelvin, eventually I'd get a gas that became hotter as I tried to cool it as if I were heating it with a flame?
    Well I tried to explain it as best I could from how I understood it, which parts of my comments was I not clear on?
    I suspect nothing is clear to him.

    Frank, your knowledge is clearly lacking here. I can't understand how someone who knows he is not qualified can still proceed to call BS on science topic he clearly doesn't understand. I suggest letting go of preconceptions and reading up on the experiment and physics around it.
    "FrankBaker" 's reply here is a carbon copy of the one he made on the other forum. No sign of any attempt to respond to the different points made by the posters here.

    Waste of time replying, in my view.
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    That's a shame. It would have been nice to have had a discussion where we both could have learned something new.
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    Random notion, could there be any hypothetical possibility of something similar regarding speed? A "negative" speed that's faster than light?
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    "Negative" speed is just speed in the opposite direction, it is physically no different to positive speed, so no
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  32. #31  
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    Quote Originally Posted by Daecon View Post
    That's a shame. It would have been nice to have had a discussion where we both could have learned something new.
    My dear fellow, if you want to pick up the baton and make something of this thread, in spite of FrankBaker, then I'll be delighted to have my prediction proved wrong.

    If you look at the distribution function you see that exp (-E/kT) crops up in it, where T is the temperature in K. If you assign a -ve value to T, you get a weird distribution curve that can never be stable, and is not found naturally. However you can synthesise something with such a distribution, under certain extreme conditions, in the lab, temporarily. That is all that is meant by a "negative temperature".

    I find it a misleading and unhelpful idea and prefer to say that, in a non-equilibrium state, temperature is no defined.
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    Quote Originally Posted by exchemist View Post
    Quote Originally Posted by Daecon View Post
    That's a shame. It would have been nice to have had a discussion where we both could have learned something new.
    My dear fellow, if you want to pick up the baton and make something of this thread, in spite of FrankBaker, then I'll be delighted to have my prediction proved wrong.

    If you look at the distribution function you see that exp (-E/kT) crops up in it, where T is the temperature in K. If you assign a -ve value to T, you get a weird distribution curve that can never be stable, and is not found naturally. However you can synthesise something with such a distribution, under certain extreme conditions, in the lab, temporarily. That is all that is meant by a "negative temperature".

    I find it a misleading and unhelpful idea and prefer to say that, in a non-equilibrium state, temperature is no defined.

    Are you referring to the Maxwell-Boltzmann distribution? If so, can you perhaps illustrate what you mean?
    I have not seen that particular distribution in great detail in my chemistry courses.
    "The only safe rule is to dispute only with those of your acquaintance of whom you know that they possess sufficient intelligence and self-respect not to advance absurdities; to appeal to reason and not to authority, and to listen to reason and yield to it; and, finally, to be willing to accept reason even from an opponent, and to be just enough to bear being proved to be in the wrong."

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    So you don't think the hypothesis that negative absolute temperature can be a clue to the nature of Dark Energy has any validity?
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    @CES:

    For velocity distribution in gas molecules, see here: Maxwell

    the figures on the right hand side are quite useful and show how the speed varies with "a" (proportional to square root of T). This would also crop up in chemistry in terms of activation energy and reaction rate (remember and remembering that R is just the k in exchemists expression above multiplied by Avogadro's number), so you can think of reaction kinetics in terms of the energy distribution and the rate is related to the fraction of molecules with enough energy to clear the activation energy barrier...

    In stat. mech. it's a similar distribution (Maxwell) but treats more fundamental systems (the distribution of speeds referred to above can be derived from this by assuming the gas is ideal in a 3D box and quantum effects are neglible).
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  36. #35  
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    Quote Originally Posted by Daecon View Post
    So you don't think the hypothesis that negative absolute temperature can be a clue to the nature of Dark Energy has any validity?
    Don't know much about Dark Energy TBH, but I'd be surprised if they are related, where did this hypothesis come from?
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    Quote Originally Posted by PhDemon View Post
    Quote Originally Posted by Daecon View Post
    So you don't think the hypothesis that negative absolute temperature can be a clue to the nature of Dark Energy has any validity?
    Don't know much about Dark Energy TBH, but I'd be surprised if they are related, where did this hypothesis come from?
    The last paragraph of the article, if I understood it correctly.

    The achievement of the Munich physicists could additionally be interesting for cosmology. Concerning its thermodynamic behavior, negative temperature states exhibit parallels to the so-called dark energy. Cosmologists postulate dark energy as the elusive force that accelerates the expansion of the universe, although the cosmos should in fact contract because of the gravitational attraction between all masses. There is a similar phenomenon in the atomic cloud in the Munich lab: The experiment relies upon the fact that the atoms in the gas do not repel each other as in a usual gas, but instead interact attractively. This means that the atoms exert a negative instead of a positive pressure. As a consequence, the atom cloud wants to contract and should usually collapse – just as is expected for the universe under the influence of gravity. But because of its negative temperature this does not happen. The gas is saved from collapse just like the universe.
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    OK, it's a new one on me, could be something in it (but it could also be journalese )
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    Quote Originally Posted by Daecon View Post
    A "negative" speed that's faster than light?
    You seem to have picked up the baton of "nonsense posting", I would advise you to drop it. You are getting drawn in the "Crank Race".
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    Interesting thread and the articles linked to are very curious.
    There seems to be a somewhat different view of infinity being expressed in the OP's link.
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    Quote Originally Posted by xyzt View Post
    Quote Originally Posted by Daecon View Post
    A "negative" speed that's faster than light?
    You seem to have picked up the baton of "nonsense posting", I would advise you to drop it. You are getting drawn in the "Crank Race".
    I'll take that as a "no" then.

    I guess there isn't anything similar to low & high energy states that be inverted when it comes to movement speeds to create a "negative" value of measurement like with temperature.
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    Quote Originally Posted by Daecon View Post
    Quote Originally Posted by xyzt View Post
    Quote Originally Posted by Daecon View Post
    A "negative" speed that's faster than light?
    You seem to have picked up the baton of "nonsense posting", I would advise you to drop it. You are getting drawn in the "Crank Race".
    I'll take that as a "no" then.
    Wasn't it obvious enough?
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    Quote Originally Posted by FrankBaker View Post
    ''Hot'' means = lots of energy.
    "Hot" is a relative term.
    "Should any political party attempt to abolish social security, unemployment insurance and eliminate labor laws and farm programs, you would not hear of that party again in our political history. There is a tiny splinter group, of course, that believes that you can do these things. Among them are a few Texas oil millionaires, and an occasional politician or businessman from other areas. Their number is negligible and they are stupid."
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    Quote Originally Posted by Cogito Ergo Sum View Post
    Quote Originally Posted by exchemist View Post
    Quote Originally Posted by Daecon View Post
    That's a shame. It would have been nice to have had a discussion where we both could have learned something new.
    My dear fellow, if you want to pick up the baton and make something of this thread, in spite of FrankBaker, then I'll be delighted to have my prediction proved wrong.

    If you look at the distribution function you see that exp (-E/kT) crops up in it, where T is the temperature in K. If you assign a -ve value to T, you get a weird distribution curve that can never be stable, and is not found naturally. However you can synthesise something with such a distribution, under certain extreme conditions, in the lab, temporarily. That is all that is meant by a "negative temperature".

    I find it a misleading and unhelpful idea and prefer to say that, in a non-equilibrium state, temperature is no defined.

    Are you referring to the Maxwell-Boltzmann distribution? If so, can you perhaps illustrate what you mean?
    I have not seen that particular distribution in great detail in my chemistry courses.

    Sorry, quite right I did this in haste and forgot to include the link. Here it is: http://en.wikipedia.org/wiki/Maxwell...ann_statistics

    The exp(-E/kT) term that appears in it, being a -ve exponent, implies that very high energy states tend to be less populated than lower energy ones, as it is less likely that very large numbers of quanta accumulate by chance in one state than that they are spread out among several. So this state of affairs is intuitively what you would expect. Again, as you would expect, as you raise the temperature, the -ve exponent term becomes weakened (though still -ve of course), allowing more of the high energy states to be appreciably populated.

    If you make T itself -ve (impossible but just to see what happens to the function when you try), then the exponent term becomes positive (yikes!), leading to a progressive, in fact exponential, increase in the population of higher energy states relative to lower ones. This is called a "population inversion" and is the opposite of what occurs in equilibrium states in nature.

    BUT, with some systems with very few states, and a barrier to the rate of return from high levels to lower ones, you can pump the upper states artificially, to achieve such an inversion. This is the principle of the laser, for example. But it is a non-equilibrium state and left to itself will not persist.
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    Quote Originally Posted by FrankBaker View Post
    So if a physicist says that it isn't being violated, that means it isn't? No, anyone can say anything. I've re-read the article 3 times, my jaw still drops each time. It sounds like a complete joke!
    How can a gas negative in temperature also be hotter than infinite positive temperature? How can cooling something make it gain energy (temperature?)
    What a poor attempt at argumentation. No master debater are you, although you may have some syllables in common.

    The choice is between accepting the article's description of itself (and the associated peer-reviewed paper), and your uninformed characterisation of it (and the associated pronouncements of science you make in connexion). No contest: You lose to the scientists who wrote a peer-reviewed paper.

    As trolls go, you are rather subpar. The better ones are able to muster much more effective-sounding arguments, at least on occasion. You merely gibber. Hint: Boldface and underlines do not magically transform stupid into smart.
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    Quote Originally Posted by exchemist View Post
    BUT, with some systems with very few states, and a barrier to the rate of return from high levels to lower ones, you can pump the upper states artificially, to achieve such an inversion. This is the principle of the laser, for example. But it is a non-equilibrium state and left to itself will not persist.
    I'm glad that you provided your wonderful (as always) explanation. If I recall correctly, Einstein was the first to invoke in print the concept of a negative temperature in outlining an idea for what eventually would become the laser. It took decades for others to work out the technical details of how to sustain a population inversion, and now everyone has a laser. Maybe we can even use one to induce SHC in all of FrankBaker's various incarnations. I'll bring the bangers, you bring the ale.
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    Quote Originally Posted by FrankBaker View Post
    No, anyone can say anything.
    And they usually do! you should see there is some nut over in one of the other threads that actually thinks spontaneous human combustion is actually possible. you're right anyone can say anything!
    tk421 and exchemist like this.
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    Quote Originally Posted by tk421 View Post
    Quote Originally Posted by FrankBaker View Post
    So if a physicist says that it isn't being violated, that means it isn't? No, anyone can say anything. I've re-read the article 3 times, my jaw still drops each time. It sounds like a complete joke!
    How can a gas negative in temperature also be hotter than infinite positive temperature? How can cooling something make it gain energy (temperature?)
    What a poor attempt at argumentation. No master debater are you, although you may have some syllables in common.

    The choice is between accepting the article's description of itself (and the associated peer-reviewed paper), and your uninformed characterisation of it (and the associated pronouncements of science you make in connexion). No contest: You lose to the scientists who wrote a peer-reviewed paper.

    As trolls go, you are rather subpar. The better ones are able to muster much more effective-sounding arguments, at least on occasion. You merely gibber. Hint: Boldface and underlines do not magically transform stupid into smart.
    Actually I'd have thought master debater was closer to the mark than you intended.
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    You're saying negative kelvin isn't possible yet you keep mentioning the term ''negative temperature'' in terms of K over and over again.

    From Wikipedia:

    ''By contrast, a system with a truly negative temperature in absolute terms on the Kelvin scale is hotter than any system with a positive temperature. If a negative-temperature system and a positive-temperature system come in contact, heat will flow from the negative- to the positive-temperature system.''

    How is a negative temperature hotter than any system with a positive temperature? A gas at -1 Kelvin is hotter than any known star in the universe?
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    Already answered, population inversion, Maxwell-Boltzmann etc. The information has been provided, stop trolling.
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    Quote Originally Posted by PhDemon View Post
    Already answered, population inversion, Maxwell-Boltzmann etc. The information has been provided, stop trolling.
    The article mentioned TEMPERATURE also. It is saying that a gas negative kelvin is hotter than anything else in the universe.
    Temperature is the kinetic vibration of atoms. it's saying at negative kelvin atoms are gaining kinetic vibration as they're cooled down to below zero K.


    Here it is again :

    ''''By contrast, a system with a truly negative temperature in absolute terms on the Kelvin scale is hotter than any system with a positive temperature. If a negative-temperature system and a positive-temperature system come in contact, heat will flow from the negative- to the positive-temperature system.''''
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    Read the information already provided (including the links I posted for CES) and stop being a dumb schmuk.
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    Quote Originally Posted by PhDemon View Post
    Read the information already provided (including the links I posted for CES) and stop being a dumb schmuk.
    I have read it. It's referring to TEMPERATURE - the kinetic vibration of atoms. It says at negative kelvin, the system is HOTTER than any positive temperature. This means that at minus kelvin instead of losing energy (cooling a positively warm material down) the atoms are gaining kinetic vibration energy (AKA heat) as they go down the negative scale.
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    Look, I'm an idiot and even *I* understood the jist of the bloody article. Negative absolute temperature is a mathematical property, an inverted number on a numerical scale, it doesn't mean colder than nothing.
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    Quote Originally Posted by Daecon View Post
    Look, I'm an idiot and even *I* understood the jist of the bloody article. Negative absolute temperature is a mathematical property, an inverted number on a numerical scale, it doesn't mean colder than nothing.
    -50 Celsius is also an inverted number on a numerical scale, but I'd expect that forecasts of -50 Celsius would mean it's going to be pretty darn cold and not warm.

    NOTHING could be colder than zero kelvin...I'm sorry but I don't think physics is going to fly out the window. Surely this has to be a hoax
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    If you have read it (particularly the second link I gave) you haven't understood it, read it again and see how temperature is related to energy level populations (not necessarily kinetic vibrations). As those systems are not in thermal equilibrium the concept of temperature in the sense you mean is pretty ropy. You were told this by exchemist above and it is in the links I posted. How about you learn some physics (or even just read the answers people have given you) before spouting next time or will you just continue to troll?
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    Quote Originally Posted by PhDemon View Post
    If you have read it (particularly the second link I gave) you haven't understood it, read it again and see how temperature is related to energy level populations (not necessarily kinetic vibrations). As those systems are not in thermal equilibrium the concept of temperature in the sense you mean is pretty ropy. You were told this by exchemist above and it is in the links I posted. How about you learn some physics (or even just read the answers people have given you) before spouting next time or will you just continue to troll?
    I've read all of them. how do you get around the fact it said that these negative temperatures are HOTTER than even infinite positive temperature?

    http://www.escapistmagazine.com/news...e-Temperatures

    ^ NEGATIVE KELVIN ^


    '' As one scientist put it, "the gas is not colder than zero Kelvin, but hotter. It is even hotter than at any positive temperature - the temperature scale simply does not end at infinity, but jumps to negative values instead."'

    What a crank! These atoms are the hottest thing in the universe?
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    Trolling it is then, you are just proving the point you can lead an idiot to information but you can't make him think. The answer to your question is in the links provided above. Reported for trolling and I'm done with you.
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    Quote Originally Posted by FrankBaker View Post
    NOTHING could be colder than zero kelvin.
    That's correct.

    Negative absolute temperature is when the atoms have so much kinetic energy in them they're unable to convert any of their potential energy into even more kinetic energy. That's why they're considered hotter than infinite temperature, as demonstrated in the diagram in the article.

    Technically they can't be said to have a positive value for their temperature because it's hotter than infinite, so they're said to have a negative absolute temperature instead.
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    Quote Originally Posted by Daecon View Post
    Quote Originally Posted by FrankBaker View Post
    NOTHING could be colder than zero kelvin.
    That's correct.

    Negative absolute temperature is when the atoms have so much kinetic energy in them they're unable to convert any of their potential energy into even more kinetic energy. That's why they're considered hotter than infinite temperature, as demonstrated in the diagram in the article.

    Technically they can't be said to have a positive value for their temperature because it's hotter than infinite, so they're said to have a negative absolute temperature instead.
    The articles say the atoms were chilled. Not heated up. Unless chilling causes the atoms to gain kinetic energy.
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    Just more trolling by the sock puppet of Gaiagirl95
    Its the way nature is!
    If you dont like it, go somewhere else....
    To another universe, where the rules are simpler
    Philosophically more pleasing, more psychologically easy
    Prof Richard Feynman (1979) .....

    Das ist nicht nur nicht richtig, es ist nicht einmal falsch!"
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  62. #61  
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    Quote Originally Posted by FrankBaker View Post
    Quote Originally Posted by Daecon View Post
    Quote Originally Posted by FrankBaker View Post
    NOTHING could be colder than zero kelvin.
    That's correct.

    Negative absolute temperature is when the atoms have so much kinetic energy in them they're unable to convert any of their potential energy into even more kinetic energy. That's why they're considered hotter than infinite temperature, as demonstrated in the diagram in the article.

    Technically they can't be said to have a positive value for their temperature because it's hotter than infinite, so they're said to have a negative absolute temperature instead.
    The articles say the atoms were chilled. Not heated up. Unless chilling causes the atoms to gain kinetic energy.
    To reprise:-

    "FrankBaker" is not interested in physics. His object is to annoy scientists. You can expect him to try to keep this discussion going for a long time by (a) being deliberately obtuse and /or (b) by periodically injecting some new bit of nonsense when the argument flags.

    This thread will go nowhere useful."

    Mostly proved, I think.

    However I'm delighted to acknowledge that the pessimism of my last sentence was not wholly justified, in that some of us have had a good discussion about the relationship between temperature and the Maxwell Boltzmann distribution of statistical thermodynamics.
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    Quote Originally Posted by FrankBaker View Post
    NOTHING could be colder than zero kelvin...I'm sorry but I don't think physics is going to fly out the window. Surely this has to be a hoax
    Yes, you're right. It's a hoax. The authors just admitted it on BBC Radio 5 Live. In fact, all scientists everywhere have admitted that everything they've been saying for the last 500 years has all been a huge joke.

    You can go away now for some more masterful debating in the privacy of your own home.
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    Quote Originally Posted by tk421 View Post
    Quote Originally Posted by FrankBaker View Post
    NOTHING could be colder than zero kelvin...I'm sorry but I don't think physics is going to fly out the window. Surely this has to be a hoax
    Yes, you're right. It's a hoax. The authors just admitted it on BBC Radio 5 Live. In fact, all scientists everywhere have admitted that everything they've been saying for the last 500 years has all been a huge joke.

    You can go away now for some more masterful debating in the privacy of your own home.
    Arf arf.
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    This is an interesting thread. Too bad Frank has to muck it up with his incessant trolling. Perhaps a week off for Frank will give qualified people time to discuss it in a reasonable manner.
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    Is there a variable scale of negativity, or is it just "negative" vs. a positive variable of Kelvin?
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    It's all to do with the population of each energy level. How "negative" the temperature is is determined by the relative populations in the same way as how hot something is. It's just that for negative temperatures the higher energy states are more populated than the lower ones. (In positive temperatures the higher energy states are less populated than lower ones).
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    Quote Originally Posted by Daecon View Post
    Is there a variable scale of negativity, or is it just "negative" vs. a positive variable of Kelvin?
    Yes, see here.
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    Quote Originally Posted by xyzt View Post
    Quote Originally Posted by Daecon View Post
    Is there a variable scale of negativity, or is it just "negative" vs. a positive variable of Kelvin?
    Yes, see here.
    Right, now that we've got rid of the troll, we can discuss this properly.

    I have to say I remain unsure of the helpfulness of the concept of negative temperature, when thinking about a population inversion.

    One question I have is whether a heat sink at a negative temperature would permit work to be done by a heat engine with a heat source at absolute zero. I would have thought not. If this is right, it seems to me it calls into question the validity - or at any rate the usefulness - of the concept.

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    Quote Originally Posted by exchemist View Post
    One question I have is whether a heat sink at a negative temperature would permit work to be done by a heat engine with a heat source at absolute zero. I would have thought not. If this is right, it seems to me it calls into question the validity - or at any rate the usefulness - of the concept.

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    If one considers the definition of thermodynamic entropy: , then adding heat to a negative temperature would decrease entropy. Thus, we would not expect heat to flow to a lower temperature when that temperature is negative.
    There are no paradoxes in relativity, just people's misunderstandings of it.
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    Quote Originally Posted by KJW View Post
    Quote Originally Posted by exchemist View Post
    One question I have is whether a heat sink at a negative temperature would permit work to be done by a heat engine with a heat source at absolute zero. I would have thought not. If this is right, it seems to me it calls into question the validity - or at any rate the usefulness - of the concept.

    Views?
    If one considers the definition of thermodynamic entropy: , then adding heat to a negative temperature would decrease entropy. Thus, we would not expect heat to flow to a lower temperature when that temperature is negative.
    OK, fair enough, so far as the definition of entropy goes. But I'd still have thought the idea of temperature as determining the direction of heat flow is about the most basic definition of temperature of all.

    If you need to abandon that for a negative temperature to make any sense, then I'm not sure you are really speaking of a temperature in any useful sense, are you?
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    It seems much of the confusion comes from the typical meaing of the word "negative".

    Perhaps a different word should have been used instead, but which one? Transfinite? Inverted?
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    Quote Originally Posted by Daecon View Post
    It seems much of the confusion comes from the typical meaing of the word "negative".

    Perhaps a different word should have been used instead, but which one? Transfinite? Inverted?
    No, it's negative all right, that much is unambiguous. The issue really is which is the more fundamental concept: that heat flows from a higher temperature to a lower, or that heat flows in the direction that increases entropy. Common sense, and the original (historical) concept of temperature, suggest the former, but as KJW points out, you get a conflict between this and the latter, if you allow yourself to conceive of a -ve temperature.

    I suspect KJW (and maybe other physicists) will say it's a bit like √-1 in maths. It may be impossible in the realm of natural phenomena, but if you can describe what it implies in a consistent way theoretically, there is no reason why it should not be a good concept; and then it is a matter of seeing if you can create a physical condition corresponding to it.

    The other problem with -ve temperature, though, is that because it is so unnatural, we can only create it in a highly artificial way, in a system that has very few allowed states; not at all like the natural situations with a profusion of energy levels that statistical thermodynamics is really aimed at accounting for.

    So it seems to me to be just a bit of a curiosity, that is almost designed to confuse - hence ideal for science journalists, for whom "doing the impossible" is great for headlines.

    But as usual when I attempt physics, I wait for correction from those with greater proficiency.
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    It reminds me of my tutor saying that if people were used to dealing with "beta" (i.e 1/kT) rather than temperature (with all the baggage that word has from general usage) then teaching physical chemistry would be a lot easier
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    Quote Originally Posted by exchemist View Post
    I'm not sure you are really speaking of a temperature in any useful sense, are you?
    I should remark that what I said was intended to be mathematically formal rather than an attempt to appeal to physics. I personally don't think of negative temperature as a useful concept. It is typically only applicable to two-level systems because additional levels would tend to prevent the distribution from being Boltzmann (thermal) for which any temperature can be applied.
    There are no paradoxes in relativity, just people's misunderstandings of it.
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    Quote Originally Posted by exchemist View Post
    I suspect KJW (and maybe other physicists) will say it's a bit like √-1 in maths.
    Or maybe it's like
    There are no paradoxes in relativity, just people's misunderstandings of it.
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    Quote Originally Posted by KJW View Post
    Quote Originally Posted by exchemist View Post
    I'm not sure you are really speaking of a temperature in any useful sense, are you?
    I should remark that what I said was intended to be mathematically formal rather than an attempt to appeal to physics. I personally don't think of negative temperature as a useful concept. It is typically only applicable to two-level systems because additional levels would tend to prevent the distribution from being Boltzmann (thermal) for which any temperature can be applied.
    EXACTLY. That is precisely my scepticism about the concept.

    All the same, from the viewpoint of the history and philosophy of science, I find it significant that nowadays physicists do seem - slightly perversely - to define temperature in terms of entropy, whereas historically the concept of entropy was developed by reference to temperature.

    Not having had the (doubtful?) pleasure of tutorials with Peter Atkins, I think I will leave the idea of thinking in terms of PhDemon's beta = 1/kT for another day, when I am thinking particularly clearly.
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    Quote Originally Posted by exchemist View Post
    I find it significant that nowadays physicists do seem - slightly perversely - to define temperature in terms of entropy, whereas historically the concept of entropy was developed by reference to temperature.
    One thing that is peculiar about temperature is that 1 K is defined as the triple point of water. But how does one cut up a temperature?
    There are no paradoxes in relativity, just people's misunderstandings of it.
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