Is Negative Kelvin a Real Concept?

[Chemmjr18]

I recently saw an article that talked about negative Kelvin. How's this possible?

 

[Nugatory]

You said "negative Kelvin". Did you mean "negative temperature" instead? If so, Googling for that will find some good explanations, including http://math.ucr.edu/home/baez/physics/ParticleAndNuclear/neg_temperature.html

 

[Vanadium 50]

Can you point us to the article?