Hmmm, apparently not. OK, I see what you are talking about: exotic energy states. Quantum gas goes below absolute zero - Ultracold atoms pave way for negative-Kelvin materials. Abstract What is negative energy? In my mind this is saying that 0.0 Kelvin is inadequate to describe all energy states. So despite the physicists describing this as negative K, I describe it as an exotic energy state associated with quantum mechanics that's needs a different scale than Kelvin. In other words, apples and oranges: they are made of the same basic atoms but they are not exactly comparable. I will of course, have to continue reading about this to understand how it relates to the original Kelvin scale.
If we're going to get into negative energy and negative matter those are quantum states that do not relate to sound theory in any way at all.
