by Crosbie Smith

Pub Athlone Press, London, 1998, ISBN 0 485 11431 3 hb/ 0 485 12145 X pb

xii + 404 pp

Review by Chris Clarke

The revolution of thought in the seventeenth century which initiated modern science – starting with the English atomists, continued by Newton and followed up by the French school of rational mechanics in the eighteenth century – had established the image of a soulless universe with particles moving in the void under forces specified by deterministic laws. From this extreme position, there then took place a reaction in the nineteenth century. A revised cosmology emerged which was "fundamentally mechanical in nature … [but ensured] a role for human free will in directing energy during its transformation from states of intensity to states of diffusion." Although in the thinking of the majority of present day physicists the pendulum has now returned to the older atomistic philosophy, and the term "energy" has dropped into a background role where it is taken for granted, it is the nineteenth century significance of the term that has entered common speech and thereby informed much of recent discussions of energy in Network.

In this book, Crosbie Smith convincingly defends the thesis that the nineteenth century change in the conception of energy was the result of a deliberate "marketing strategy" by a group of North British scientists imbued with the entrepreneurial fervour of the age. The work is thus an essential reference point for any discussion of the nature of scientific "advance," providing good evidence for the interplay of social and empirical strands in this process.

In addition, however, it forms a good source for understanding this influential nineteenth century concept by tracing its historical unfolding. This started with the practical need to understand the economics of heat engines, leading first to the realisation that mechanical and thermal energy are interconvertible at a fixed "rate of exchange," and then to the vital insight (finally formulated by Carnot in 1824) that the possibility of this interconversion was limited by thermodynamic relations: the availability of energy was only half the story (a point all too often neglected today). Complementing this development in the thermodynamics of energy was the emergence of the classification of different types of energy, eventually resolving into the now familiar dichotomy into energy of motion (kinetic energy) and stored (potential) energy. The final step in this process was the demonstration by Lagrange and Hamilton that Newtonian mechanics could be recovered taking the laws of energy as thus classified as a basis, a process called by Smith "the reinvention of Newton."

I can recommend his detailed and closely argued text for any serious study of this intriguing historical episode.