Absolute Zero and Absolute Accuracy

[The Anomaly]

This is either a topic that is so blatantly obvious that it's ridiculous I'm saying it, or I'm missing something. From my limited physics knowledge, I know that absolute zero is a temperature in which the molecules are not moving whatsoever. In other words, it's the lowest possible temperature, 0 K. We continuously push closer and closer to this temperature, attaining 0.1, 0.000001, 0.00000001, etc.

My question is this. Taking aside any physical reasons why it would be impossible to attain 0K, if it really is, then how would we know that we got there? I mean, we can keep getting smaller and smaller, but if we can never go past 0, then how will we ever prove we can get there? There's no way anyone can measure it to the absolute accuracy--and therefore we could easily be some infinitesimal amount above 0K, but we can't be for certain, as we can never have absolute accuracy.

Does this make any sense?

 

[Andy Resnick]

If I understand what you are saying, the answer is 'because temperature is a log scale in energy' In terms of statistical physics, many systems are characterized by a factor exp(-E/kT).

As a result of temperature being a log scale, there is no way to achieve 0 K. And, it is not true that "absolute zero is a temperature in which the molecules are not moving whatsoever." There is still the zero-point energy.

http://en.wikipedia.org/wiki/Zero_point_energy