Conservation and Innovation : Helmholtz's Struggle with Energy ...

magnetic intensity. Maxwell realized the need for a specific interpretation of the
energy concept suited to a contiguous action theory and based on the continuity
equation. Helmholtz translated Maxwell's approach in his action at a distance
with polarized dielectric approach but was never able, even in 1894, to grasp
Poynting's new concept of localized conservation (1884-5) or Hertz's efforts at
"purifying" Maxwell's theory from action at a distance influences (1890-2). The
interpretation of potential energy in Helmholtz's theory was and still is a
challenge. J.J.Thomson in 1885 had based his comparison of electrodynamic
theories on energy grounds and Planck had been very quick at assessing in 1887
the whole problem of energy conservation, both historically and logically.
Helmholtz could not have failed to notice these developments, but at this stage he
was shifting towards a different research programme.
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In the seventies Helmholtz returned to a problem he had first faced in his 1847
paper: the application of the principle of energy conservation (PCE) to
electrodynamics. From 1847 to 1870 radical changes occurred both in the field of
Classical Electromagnetic Theory (CET) and in PCE. Helmholtz’s purpose in
1870 was to reorder the field of CET 381, with a clarification of the debate on the
basis of considerations referring to conservation of energy. This attempt lasted
for at least twenty years and was in the end successful: Helmholtz in fact played a
major role in comparing the different theories, suggested a set of experiments that
were to become extremely famous and gave an initial impulse to Lorentz's
researches.
The complexity of the CET debate at the beginning of the seventies was later
described by Helmholtz himself:
"This plentiful crop of hypotheses had become very unmanageable, and in dealing
with them it was necessary to go through complicated calculations, resolutions of
forces into their components in various directions, and so on. So at that time the
domain of electromagnetics had become a pathless wilderness. Observed facts
and deductions from exceedingly doubtful theories were inextricably mixed up
together. With the object of clearing up this confusion I had set myself the task of
381 Helmholtz,Hermann. Vorwort zu: Heinrich Hertz, Prinzipien der Mechanik.
Leipzig: Barth,1894; pp. VII-XXVII. Tr. in Hertz, H. The Principles of Mechanics,
Presented in a New Form. Tr. by D.E.Jones and T.Walley. London: 1899. Repr. New York:
Dover,1956. P.4.