|
Engineering Hall of Fame
Heinrich
Hertz: Familiar Name, But Who Was He Really?
by
Michael N. Geselowitz, Ph.D.
Engineers who
possess even a cursory knowledge of the history of electrical
engineering are probably familiar with the name Heinrich Hertz.
They may know that Hertz was the first to demonstrate
experimentally the production and detection of the electromagnetic
waves predicted by James Clerk Maxwell. He measured their
wavelength and velocity, and he demonstrated the nature of their
reflection and refraction. They may know, too, that despite his
tragic premature death from blood poisoning, which he
contracted from a tooth infection, he produced a book titled Untersuchungen
über die Ausbreitung der Elektrischen Kraft (Investigations
on the Propagation of Electrical Energy), which is considered
one of the classics of modern physics.
And most who are
familiar with Heinrich Hertz probably know that the unit of
frequency — cycles per second — was renamed the Hertz (Hz) in
the 1930s in his honor, and that the IEEE established an award in
the radio waves field in 1987 called the Heinrich Hertz Medal. Few
engineers, however, know much about Hertz’s fascinating, albeit
brief, life story.
Hertz was born
in Hamburg, Germany in February 1857 to a father from a wealthy,
educated and incredibly successful family that had converted from
Judaism to Lutheranism a generation before. Heinrich’s mother
was the daughter of a Lutheran minister. His father was a lawyer
and politician, as were two of his brothers. Another brother was a
successful musician, his sister married a prominent artist, and a
nephew, Gustav Hertz, would win the Nobel Prize for physics in
1925.
Though it was
short, his life was one of constant motion both intellectually and
geographically. Hertz demonstrated an early aptitude for
mathematics and science, and eventually began studying civil
engineering. He worked his way from Hamburg to Frankfurt to
Dresden, where Professor Philipp von Jolly (later the doctoral
supervisor to Max Planck) convinced him to switch to physics. So,
in 1878, at the age of 21, he traveled to Berlin and
enrolled in the university to study under Gustav Kirchhoff and
Hermann Helmholtz. There he began a dissertation on the nature of
electromagnetic induction in rotating conductors, receiving his
doctorate, magna cum laude (quite rare in Berlin in those days), in
1880 — in less than two years! He then began working as Helmholtz’s
assistant, performing research on mechanical hardness and stress
and producing seminal papers in that field.
In 1883, Hertz
pursued an opportunity to move one rung up the academic ladder. He
moved to the University of Kiel as a Privatdozent
(Lecturer), where his research returned to electromagnetics.
However, a promised professorship kept being delayed until, in
1885, he was offered a full professorship at the Technische
Hochschule in Karlsruhe, which he grabbed. Soon after he left
Kiel, an assistant professorship was created there and was filled by
Max Planck, but it was at Karlsruhe that Hertz would do his
groundbreaking work on electromagnetic waves. In between it all,
he married Elizabeth Doll, daughter of his colleague
Dr. Max Doll, in 1886. They would have two children, Johanna, born
in 1887, and Mathilde, born in 1891.
Hertz published
his electromagnetic wave work in 1888 and was instantly acknowledged as a
leading physicist of the day. Offers poured in and in 1889, he
moved to the University of Bonn. While there, he turned his
attention back to mechanics and to do for that field what Maxwell had done for
electromagnetism — reduce it to a simple set of equations based,
in this case, on only mass, time and length. Unfortunately, his
on-again, off-again battles with infection took a turn for the
worse, and he died on New Year’s Day 1894, just weeks shy of his
37th birthday. In a fitting end to his peripatetic life, he was
returned to Hamburg for burial.
But Hertz’s
story does not end with his death. First, it is fair to say that
at least intellectually, he continued as a moving target after he
died. His assistant, Philipp Lenard, saw to the publication of
Hertz’s magnum opus on mechanics, Die Prinzipien der Mechanik,
in Neuen Zusammenhänge Dargestellt (The Principles of
Mechanics Presented in a New Form) in 1895. Interestingly, his
approach did not find widespread acceptance among physicists, who
would soon focus their attention on quantum mechanics and
relativity, but it was embraced by philosophers of science and, in
particular, strongly influenced Ludwig Wittgenstein, who had
studied engineering.
Also,
unfortunately, although Hertz’s body finally found rest
geographically, his family did not. In the 1930s, his wife and
daughters had to flee Germany because they were considered by the
Nazis to be Jews, despite the strong Lutheran roots on both sides
of the family. A final story perhaps best illustrates those times.
One Nazi functionary suggested to the Physical Society of Berlin
that they not use the term 'Hertz,' a unit named after a non-Aryan. His clever idea:
continue to use the abbreviation ‘Hz’ when communicating with
foreign colleagues to avoid confusion, but refer to the unit in
Germany as a “Helmholtz” and not a “Hertz.” The German
scientists — even though they had not fled the Nazi regime —
refused to go along, and so the legacy of Hertz remains, both in
Germany and around the world.
Michael
N. Geselowitz, Ph.D., is director of the IEEE History Center at
Rutgers University in New Brunswick, N.J. Visit the IEEE History
Center's Web page at: www.ieee.org/organizations/history_center/
|
