1.1.1 History
Knowledge about heat and temperature was not available, let us say, two hundred years ago. Much confusion existed at that time about the nature of heat. Since language had its origin even earlier than that, a considerable share of this confusion is maintained in our present-day language. Let us look, for example, at the excerpt from a dictionary reproduced in Fig. 1.1. Several different meanings are listed there for the noun heat. A good number of these have a metaphorical meaning and can be eliminated immediately for scientific applications (entries 4, 6, and 8 -15). Taking out duplications and trying to separate the occasionally overlapping meanings, one finds that there remain four principally different uses of the word heat. The first and primary meaning of heat is given in entry 1: it describes the heat as a physical entity, energy, and derives it from the quality of being hot which, in turn, describes