Physics

By 1871, the year he reached the age of fifty, Helmholtz had accomplished more
than any other physiologist in the world, and he had become one of the most
famous scientists in Germany. He had worked extremely hard, often to the detriment
of his mental and physical health. He might have decided to relax his
furious pace and become an academic ornament, as others with his accomplishments
and honors would have done. Instead, he embarked on a new career, and
an intellectual migration that was, and is, unique in the annals of science. In
1871, he went to Berlin as professor of physics at the University of Berlin.
The conversion of the physiologist to the physicist was not a miraculous rebirth,
however. Physics had been Helmholtz’s first scientific love, but circumstances
had dictated a career in medicine and physiology. Always a pragmatist,
he had explored the frontier between physics and physiology, earned a fine reputation,
and more than anyone else, established the new science of biophysics.
But his fascination with mathematical physics, and his ambition, had not faded.
With the death of Gustav Magnus, the Berlin professorship was open. Helmholtz
and Gustav Kirchhoff, professor of physics at Heidelberg, were the only candidates;
Kirchhoff preferred to remain in Heidelberg. “And thus,” wrote du Bois-
Reymond, “occurred the unparalleled event that a doctor and professor of physiology
was appointed to the most important physical post in Germany, and
Helmholtz, who called himself a born physicist, at length obtained a position
suited to his specific talents and inclinations, since he had, as he wrote to me,
become indifferent to physiology, and was really only interested in mathematical
physics.”
So in Berlin Helmholtz was a physicist. He focused his attention largely on
the topic of electrodynamics, a field he felt had become a “pathless wilderness”
of contending theories. He attacked the work of Wilhelm Weber, whose influence
then dominated the theory of electrodynamics in Germany. Before most of his
colleagues on the Continent, Helmholtz appreciated the studies of Faraday and
Maxwell in Britain on electromagnetic theory. Heinrich Hertz, a student of Helmholtz’s
and later his assistant, performed experiments that proved the existenceof electromagnetc waves and confirmed Maxwell’s theory. Also included among
Helmholtz’s remarkable group of students and assistants were Ludwig Boltzmann,
Wilhelm Wien, and Albert Michelson. Boltzmann was later to lay the
foundations for the statistical interpretation of thermodynamics (see chapter 13).
Wien’s later workon heat radiation gave Max Planck, professor of theoretical
physics at Berlin and a Helmholtz prote´ge´, one of the clues he needed to write
a revolutionary paper on quantum theory. Michelson’s later experiments on the
velocity of light provided a basis for Einstein’s theory of relativity. Helmholtz,
the “last great classical physicist,” had gathered in Berlin some of the theorists
and experimentalists who would discover a new physics.