Quantum Gas Goes Below Absolute Zero

First time accepted submitter mromanuk writes in with a story about scientists at Ludwig Maximilian University of Munich who have created an atomic gas that goes below absolute zero. "It may sound less likely than hell freezing over, but physicists have created an atomic gas with a sub-absolute-zero temperature for the first time. Their technique opens the door to generating negative-Kelvin materials and new quantum devices, and it could even help to solve a cosmological mystery."

Comments

Re:better explanation

[hydrofix]

An interesting quotation from that article:

A substance with a negative temperature is not colder than absolute zero, but rather it is hotter than infinite temperature.

It seems this is a very specific quantum mechanical perversion, and no classical systems can reach the state quantum physicists call "negative temperature".

Re:better explanation

[Anonymous Coward]

Is this proof of a simulated universe?

Dark Energy

[metamarmoset]

Observtions during the experiment could point to new research on dark energy.

From TFA:

Another peculiarity of the sub-absolute-zero gas is that it mimics 'dark energy', the mysterious force that pushes the Universe to expand at an ever-faster rate against the inward pull of gravity. Schneider notes that the attractive atoms in the gas produced by the team also want to collapse inwards, but do not because the negative absolute temperature stabilises them. “It’s interesting that this weird feature pops up in the Universe and also in the lab,” he says. “This may be something that cosmologists should look at more closely.”