Negative temperatures , BELOW 0 Kelvin?-Confirmation please

[cephron]

"Negative temperatures", BELOW 0 Kelvin?--Confirmation please

Someone shared this article with me:

http://www.huffingtonpost.com/2013/...d-setting-negative-temperature_n_2404666.html

...And I've seen a couple others apparently referencing the same thing. If it's a hoax, it's beyond my ability to identify it. But this is a rather extraordinary claim. Can anyone clarify the reliability and implications of this discovery? Many thanks...

 

[Jorriss]

Negative temperatures are not below absolute zero. They are actually hotter than any positive temperature in the sense that, heat will flow out of the negative temperature system to the positive temperature system.

I was under the impression negative temperatures have already been experimentally reached (at least Pathria stated so in his stat mech book).

 

[D H]

In short, no it's not a hoax. It just doesn't what you think it means. Despite the name, it does not mean "colder than absolute zero". Just the opposite; negative temperatures are hot.

There's an ongoing discussion on negative temperatures in this thread: [thread]662268[/thread].

I'm closing this thread since there's no reason to have two active threads on the same subject.