ABSTRACT
As mentioned before, the denitions of “absolute” temperature are given only as ratios or dierences of values. erefore, normalization constants are required to make the relationship of temperature with another physical quantity determined. ese denitions may be said to provide a “blank tape,” which is necessary for temperature measurement, but leaves free the choice as regards both the size of the graduation in unit intervals and the position of the “zero” value on the tape. ese are the two degrees of freedom characteristic of any linear scale. In the case, for instance, of the unit of length, the meter, it is appropriate to dene it in such a way as to maintain the additive property in the classical isotropic space. In this respect, in the absolute temperature denition of Equation 65.3, the space of heat-that is, of energy-is used, whereas in his rst denition (Equation 65.2), Lord Kelvin used the space of mechanical work equivalent to heat. e transformation between the two denitions is not linear, but logarithmic, as a reection of the fact that the rst denes a temperature ratio and the second a temperature dierence.
