[AntonioLao]

Why is it very difficult to reach absolute zero temperature? This is where all motions stop.

[dleviwing]

Originally Posted by AntonioLao Why is it very difficult to reach absolute zero temperature? This is where all motions stop.

Because motion is constant and temperature is only valid with degree of freedom.
Any concept that states motion can be stopped is wrong. Motion can only be changed from one form to another.

[Mr. Nobody]

If all motion stops at absolute zero, would it mean that matter waves turn flat and seize to exist? Super cooled liquids as they approach absolute 0 have been shown to become coherant and turn into a quantum state. Exterpolate that further to absolute zero perhaps coherance gives way to evaporation?

[Guille]

I believe it's so dificult to achieve zero temperature because as temperature, kinetic energy or any kind of motion apporaches zero, the potential energy approaches infinity, as does space and electric force. But if the electric force is infinite then the magnetic force must also be infinite, and therefore also should be time. But as we are stopping motion, that is, reducing time, it can't be that time approaches infinite. So it doesn't, can't.

[AntonioLao]

the following excerpt from the internet indicated that
It can be shown from the laws of thermodynamics that the temperature can never be exactly absolute zero; this is the same principle that ensures no system may be 100% efficient, although it is possible to achieve temperatures arbitrarily close to it. At very low temperatures in the vicinity of absolute zero, matter exhibits many unusual properties including superconductivity, superfluidity, and Bose-Einstein condensation. In order to study such phenomena, scientists have worked to obtain even lower temperatures. As of 2005, the lowest temperature Bose-Einstein condensate achieved was 450 pK, or 4.5 × 10-10 K. This was performed by Wolfgang Ketterle and colleagues at the Massachusetts Institute of Technology (A Leanhardt et al. 2003 Science 301 1513). ( http://physicsweb.org/article/news/7/9/8 ). The coldest temperature ever produced was 250 pK [2] ( http://boojum.hut.fi/research/magnetism/zero.html ) during an experiment on nuclear magnetic ordering in the Helsinki University of Technology's Low Temperature Lab