Unities and a Unifier
Science is largely a bipartisan endeavor. Most scientists have no difficulty identifying with one of two camps, which can be called, with about as much accuracy as names attached to political parties, theorists and experimentalists. An astute observer of scientists and their ways, Freeman Dyson, has offered a roughly equivalent, but more inspired, division of scientific allegiances and attitudes. In Dyson's view, science has been made throughout its history in almost equal measure by “unifiers” and “diversifiers.” The unifiers, mostly theorists, search for the principles that reveal the unifying structure of science. Diversifiers, likely to be experimentalists, work to discover the unsorted facts of science. Efforts of the scientific unifiers and diversifiers are vitally complementary. From the great bodies of facts accumulated by the diversifiers come the unifier's theories; the theories guide the diversifiers to new observations, sometimes with disastrous results for the unifiers.
The thermodynamicists celebrated here were among the greatest scientific unifiers of the nineteenth and early twentieth centuries. Three of their stories have been told above: of Sadi Carnot and his search for unities in the bewildering complexities of machinery; of Robert Mayer and his grand speculations about the energy concept; of James Joule's precise determination of equivalences among thermal, electrical, chemical, and mechanical effects. Continuing now with the chronology, we focus on the further development of the energy concept. The thermodynamicist who takes the stage is Hermann Helmholtz, the most confirmed of unifiers.
Helmholtz, like Mayer, was educated for a medical career. He would have preferred to study physics and mathematics, but the only hope for scientific training, given his father's meager salary as a gymnasium teacher, was a government schol-