hissingnoise, isn't - 0 meaningless? Do you mean < 0°K? (I could be mistaken.)
[Edited on 1/14/13 by bfesser]hissingnoise - 14-1-2013 at 09:09
Strict accuracy having flown the coop, I'd considered; "Cold? It's fifty below below!"
smaerd - 14-1-2013 at 10:06
How? What? No?Wait it's yes? noo...? what? If you get the paper I want to read it as well. The skeptic in me is raging but I guess if it's been proven
it's been proven.DJF90 - 14-1-2013 at 10:59
Does -0*C exist? Apparently so, according to my refrigerated chiller. It counts down 02, 01, 00, -00, -01 -02 etc. In this temperature regime it takes
about 1.5-2min/del*C. I plotted it in excel once to see how far in advance I'd have to turn it on before use, based upon the ambient and what
temperature is required.bfesser - 19-1-2013 at 09:25
For anyone interested in reading the paper or the perspective piece from <em>Science</em>, they're available <a
href="viewthread.php?tid=19098&page=11#pid271598">here</a>, courtesy <a
href="member.php?action=viewpro&member=gsd">gsd</a>.Glucose Oxidase - 19-1-2013 at 11:58
Excuse me if i sound foolish or something , but are talking about -0*C (Celsius) or -0*K (Kelvin) because as afar as i remember 0*K can NOT be
achieved because by extrapolating the volume-temperature graph to -273.(some decimals)*K corresponds to 0 volume i.e the gas no longer existsGlucose Oxidase - 19-1-2013 at 12:15
After reading the article hissingnoise mentioned the scientist haven't reached real -0*K but they reached -0*K "By Definition" (by our definition of
temperature) so the universe is perfect but humans are defective.
but something caught my eyes
Quote:
Instead, the engine could not only absorb energy from the hotter medium, and thus do work, but, in contrast to the usual case, from the colder medium
as well
doesn't that contradict the laws of entropy?Endimion17 - 19-1-2013 at 16:49
Thermodynamics is something we derive from statistics. Guys, this is quantum physics. Abandon all hope, ye who enter here.
It's not particle physics, astrophysics, fluids or electromagnetism. It's quantum physics. All I remember about negative absolute temperatures is that
they're possible, theoretically. So this is like the first time it's been done in the lab.
If you want my explanation, you won't get it. I knew a tiny bit about this, but not anymore.watson.fawkes - 21-1-2013 at 08:57
Thermodynamics is something we derive from statistics. Guys, this is quantum physics. Abandon all hope, ye who enter here.
It's not particle physics, astrophysics, fluids or electromagnetism. It's quantum physics.
Sort of. Negative
temperatures are well-defined in classical statistical mechanism, but they only appear in systems with a strict maximum of energy, and so generally
require a quantum effect to be realizable.
The real significance of this result is contained in the title of the paper: Negative Absolute Temperature for Motional Degrees of Freedom.
The key word is "motional". What the experimenter did was to create a system with a maximum kinetic energy. This is a pretty good trick, but it's not
anything much like how the press coverage went. Previous systems had negative temperatures in other energy modes, most typically intrinsic spin vs.
external magnetic field.
