Potato potato... Negative temperature means that entropy decreases when you add energy to a system, typically because you're approaching a local maxima for the

Potato potato... Negative temperature means that entropy decreases when you add energy to a system, typically because you're approaching a local maxima for the energy state it's in. Bose Einstein Condensates are a nice example of this behaviour.... and it's as "real" a negative temperature as you can have.