31 The Equation dQ i= T · dS is form-invariant
Following sections 8 and 12 of the first part of this treatise, the product T · dS jnecessarily transforms the same way as T · k , that is by multiplication by the root factor. In 26 and 27 we established dQ' = dQ · √ and hence the relation
T · dS j = dQ or dS = dQ / T
is form-invariant too, independant of our option in favour of temperature or entropy to be relativistically invariant. This result has been announced in section 14 .
We did not suppose the invariance of this relation. The invariance is the result of our investigations on the transformations of k · T and heat quantities Q . In section 34 we will present some further relations between T and dS jincluding the notion of molar heat capacities.