PHYSICAL LIMITS ON THE NOTION OF VERY-LOW TEMPERATURES

Standard statistical thermodynamic views of temperature fluctuations p redict a magnitude (root((Delta T)(2)) /T) approximate to root(k(B)/C) for a system with heat capacity C. The extent to which low temperatur es can be well defined is discussed for those systems that obey the th ermodynamic third law in the form lim((T-->0)) C=0. Physical limits on the notion of very low temperatures are exhibited for simple systems. Application of these concepts to bound Bose condensed systems are exp lored, and the notion of bound boson superfluidity is discussed in ter ms of the thermodynamic moment of inertia.