Absolute zero sounds like an unbreachable limit beyond which it is impossible to explore. In fact there is a weird realm of negative temperatures that not only exists in theory, but has also proved accessible in practice. An improved way of getting there, outlined last week, could reveal new states of matter...There's more at New Scientist, but I don't understand any of it, so you'll need to explore it on your own.
Creating negative-temperature systems to see what other "bizarro world" properties they might have is tricky. It is certainly not done by cooling an object down to absolute zero. It is, however, possible to leap straight from positive to negative absolute temperatures.
Their definition of negative temperatures is a bit bogus. They even admit that negative temps are hotter than positiive temps. Imagine you had a pachinko machine, and the balls were gas molecules. Absolute zero (from the positive side) would be if all the balls were at the bottom, not moving, in their own little slot. Now imagine that the pachinko machine is upside down and all the balls have maximum potential energy. Now they are all at the top, also in their own slots. That would be absolute zero on the negative side. In order for the entropy to increase a ball would have to fall, which would be a decrease in energy.
ReplyDeleteI get it now. Magic.
ReplyDelete