Re: [Phys-l] Negative kelvin temperatures

[Bernard Cleyet <bernardcleyet@redshift.com>]

If you're near a library, check out the Sci. Am. article on this; rather 
some time ago.  Also a recent one I find 1994.

However, easier:  Denker to the rescue, as usual.

http://www.av8n.com/physics/neg-temp.htm



bc, thankful as JD saves him time.

p.s. As bc had heard (read) of neg. temp 50 years ago, he thinks more 
people should read Sci. Am.  Well, maybe not.  He thinks Sci Am. is a 
shell of its former self.  Try the Brit. journal New Scientist?

Dan Crowe wrote:

> On another list, the claim was made that in a system with a finite
> number of energy levels, population inversion implies a negative kelvin
> temperature.  The following Wikipedia article was cited as evidence:
>
> http://en.wikipedia.org/wiki/Negative_temperature 
>
> I had never heard this claim of negative kelvin temperature before.  My
> first reaction is that a system with population inversion is not in
> thermal equilibrium, so it doesn't make sense to determine the
> temperature of a system based on population inversion.  I'm not even
> sure that the system has a well defined temperature.  Can someone
> familiar with this concept please discuss its merits?
>
> Thanks,
>
> Daniel Crowe
> Loudoun Academy of Science
> dan.crowe@loudoun.k12.va.us
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