Below Absolute Zero
Discussion
hornet said:
So have they broken the concept of absolute zero, or just moved the point of absolute zero to a lower value?
No, neither. The definition of temperature being used here isn't the intuitive one you're familiar with. In statistical mechanics we define temperature as T=(dS/dE)^-1 which is basically 1/T. Now it should be easy to see that as T→0, 1/T approaches +∞ and that negative temperatures are in fact hotter than any positive temperature.The wired.co.uk article is tosh. It's wrong on so many levels. In one instance it says, "At absolute zero particles were thought to have zero energy." This was never the case; at least not since the 30s. Allow me to explain. According to old quantum theory, the energy levels in a harmonic oscillator were given by:
E=nhv
At the lowest energy level, by definition, n=0, which means the system would have zero energy and be in a state of complete rest. However, wave mechanics and the uncertainty principle tells us that a state of such completely defined position and momentum is not possible, and that the energy levels of an oscillator are in fact given by:
E=(n + ½)hv
so that even when n=0 in the ground state, there is still a residual zero-point energy.
I couldn't be bothered reading the rest.
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