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

Not as new as it seems

[Grantbridge]

Lasers have had negative temperature for decades!

Re:better explanation

[serviscope_minor]

This is one of the things I love about slashdot. People with no knowledge of a subject call professionals "retarded" and get modded insightful.

It seems to me to be a retarded description, like calling infinity + 1 a negative number.

Think about reciprocals.

They need to use a proper name for it,

How about "nagative temperature". That's a proper name for it.

Temperature is defined by energy and entropy. Add energy and the entropy increases. That means the temperature is positive. How positive is how big that change is. Nice, straightforward, works well. Does whay you expect.

Then some quantum physicists discovered that adding energy makes the entropy go down. Well, plug that into the definition of temperature and the number comes out negative.

So basically, what you are claiming is that physicists are retarded because you don't like how the maths work out and you would rather they change the perfectly good classical definition of temperature to fit your sensibilities.

Deal with it. Quantum physics is very strange and many ideas you bring with you from the classical world simply don't work.

That doesn't make the professional physicists retarded, by the way.