When is a Physical Concept born? The Emergence of ‘Work’ as a Magnitude of Mechanics

Abstract

The physical magnitude ‘work’ has a long history. It emerged when two different practices, performed during the whole eighteenth century, met each other. The first was theoretical, practiced by philosophers and mathematicians, and was related mainly to the ‘living forces’ (vires vivae). The second was empirical, practiced by engineers, and was related to the work and the effectiveness of the motor engines. In both activities, the products ‘weight (or force) multiplied by height (or displacement)’ were used for calculations. Can we regard that these products constitute a well defined physical magnitude and are anticipations of the magnitude ‘work’? Modern historians of science assert that ‘work’, as a magnitude of mechanics, was created in France, at the beginning of the nineteenth century. Why? In order to examine these issues, a brief survey into the history of the relevant ideas will be done, and a number of characteristics, acquired by the magnitude of ‘work’ through the historical process of its construction, will be presented. These characteristics may help to depict a magnitude, in general, which is autonomous and embedded in a physical theory. Finally, from the historical data concerning the history of ‘work’, some educational implications will be considered.