This is gonna be the thread where we talk about stuff

In captain dummy-talk:

The definition of 'temperature' involves the probability distribution of energetic atoms to follow a bell-curve, with the 'temperature' being the mean on this curve.

But if you flip a the bell curve across the middle so that the high bits are all at the edge and the low bits are in the middle, you get the same mean temperature but mathematically it works out to be a negative absolute temperature instead!

So what they did was create conditions with lasers that made it easier for these atoms to stay in this reverse-bell curve probability distribution as opposed to falling back into the standard bell-curve as defined by physics!

The reason why we have this odd 'negative kelvin' problem is that, well, when Kelvin set this system up quantum mechanics didn't exist yet. Man believed the sun was made of coal, for goodness sakes.