Background

Heinrich Rudolf Hertz was born in 1857 in Hamburg, then a sovereign state of the German Confederation, into a prosperous and cultured Hanseatic family. His father Gustav Ferdinand Hertz (originally named David Gustav Hertz) (1827-1914) was a barrister and later a senator.

His mother was Anna Elisabeth Pfefferkorn.

Education

Aged six, Heinrich began tuition at the Dr. Wichard Lange School in Hamburg. This was a private school for boys headed by the famous educator Friedrich Wichard Lange. The school operated without religious influence; it used child-centered teaching methods, taking account of students’ individual differences. It was also strict; the students were expected to work hard and compete with one another to be top of the class. Heinrich enjoyed his time at school and indeed was top of his class.

Unusually, Dr. Lange’s school did not teach Greek and Latin - the classics - needed for university entry. The very young Heinrich told his parents he wanted to become an engineer. When they looked for a school for him, they decided that Dr. Lange’s alternative focus, which included the sciences, was the best option.

Heinrich’s mother was especially passionate about his education. Realizing he had a natural talent for making things and for drawing, she arranged draftsmanship lessons for him on Sundays at a technical college. He started these aged 11.

Aged 15, Heinrich left Dr. Lange’s school to be educated at home. He had decided that perhaps he would like to go to university after all. Now he received tutoring in Greek and Latin to prepare him for the exams.

He excelled at languages, a gift he seems to have inherited from his father. Professor Redslob, a language specialist who gave Heinrich some tuition in Arabic, advised his father that Heinrich should become a student of oriental languages. Never before had he met anyone with greater natural talent.

Heinrich also began studying the sciences and mathematics at home, again with the help of a private tutor. He had a colossal appetite for hard work. His mother said: "When he sat with his books nothing could disturb him or draw him away from them."

Although he had left his normal school, he continued attending the technical college on Sunday mornings.

In the evenings he worked with his hands. He learned to operate a lathe. He built models and began constructing increasingly sophisticated scientific apparatus such as a spectroscope. He used this apparatus to do his own physics and chemistry experiments.

Aged 17, Heinrich returned to school, the Johanneum, for a year in order to fully prepare for the classics exams for university. Having passed the exams, he promptly changed his mind again, deciding to become an architect’s apprentice. He moved to Frankfurt, where by day he worked in an architect’s office, and in the evening he read physics books in German and Ancient Greek literature in the original Ancient Greek.

In spring 1876, aged 19, he moved again, to Dresden, to study engineering. After only a few months he was drafted into the army for a year’s compulsory service. Although he enjoyed the discipline of army life, he found the army boring. Meanwhile, his interest in mathematics and physics continued to grow.

After completing his army service, the 20-year-old Hertz moved to Munich to begin an engineering course in October 1877. A month later, after much internal anguish, he dropped out of the course. He had decided that above all else he wanted to become a physicist.

He enrolled at the University of Munich, choosing courses in advanced mathematics and mechanics, experimental physics, and experimental chemistry.

In 1878 chose to continue his studies at the University of Berlin under Gustav Kirchhoff and Hermann von Helmholtz, the foremost physicists of the time. Hertz obtained his Doctor of Philosophy degree magna cum laude in 1880 with a thesis on the electromagnetic induction in rotating spheres and continued as Helmholtz's assistant for a further three years.

Career

In 1883 Hertz became a lecturer in theoretical physics at the University of Kiel. With no laboratory facilities at Kiel, he had considered more theoretical aspects of physics. Here he began his studies of the recent electromagnetic theory of James Clerk Maxwell. Maxwell's theory had been based on unusual mechanical ideas about the luminiferous ether and had not been universally accepted. Another scientist, Michelson, assisted by Morley, performed a remarkably clever experiment that proved the non-existence of this ether. In 1884, Hertz rederived Maxwell's equations by a new method, casting them in modern form without the assumption of ether.

In 1885, at the age of 28, Heinrich Hertz was appointed professor of physics at the Karlsruhe University. Hertz's early work in Karlsruhe was diverse but included several pieces of research into electrical phenomena and equipment. Helmholtz had suggested an experimental investigation of the theory to Hertz in 1879, but it was not until 1885 in Karlsruhe that Hertz found the equipment needed for what became his most famous experiments.

It is interesting to note that in 1887 he inadvertently discovered the photoelectric effect whereby ultraviolet radiation releases electrons from the surface of a metal. Although realizing its significance he left others to investigate and explain it.

In 1888, in a corner of his physics classroom at the Karlsruhe Polytechnic in Berlin, Hertz generated electric waves using an electric circuit; the circuit contained a metal rod that had a small gap at its midpoint, and when sparks crossed this gap violent oscillations of high frequency were set up in the rod. Hertz proved that these waves were transmitted through the air by detecting them with another similar circuit some distance away. He also showed that like light waves they were reflected and refracted and, most important, that they traveled at the same speed as light but had a much longer wavelength. Hertz also noted that electrical conductors reflect the waves and that they can be focused by concave reflectors. He found that nonconductors allow most of the waves to pass through. These waves originally called Hertzian waves but now known as radio waves, conclusively confirmed Maxwell's prediction on the existence of electromagnetic waves, both in the form of light and radio waves.

On April 3, 1889, Heinrich Hertz arrived in Bonn to take the position of Professor of Physics and Director of the Physics Institute as a successor to Rudolf Clausius (1822-1888). Hertz was fresh from his triumphs in Karlsruhe, where he had proved in a series of elegant experiments that the long-wavelength electromagnetic waves implicit in Maxwell’s theory existed. He also had been able to demonstrate convincingly that these waves had all the well-known properties of light waves – reflection, refraction, interference, polarization. Almost immediately Hertz became the superstar of the physics community, not merely in Germany but throughout the world of science. But during the almost five years that Hertz spent in Bonn (April 3, 1889, to January 1, 1894), he abandoned almost all experimental work and devoted three years to difficult theoretical work on mechanics, which culminated in the posthumous publication in 1894 of his book on the subject.

Why, in his hour of triumph, did Hertz turn his back on electromagnetic experiments (after completing one that he had begun in Karlsruhe), and devote three years to this book on mechanics, a book that always has mystified physicists? A practical reason (but certainly not the dominant one) is that he was increasingly ill with a series of infections during these years and thus was unable to do the laboratory research he found so rewarding both personally and professionally. He also found it difficult to find new experimental projects that promised to rival his Karlsruhe research in importance. The salient reason for his work on theoretical mechanics, however, was that as a nineteenth-century physicist, like most such physicists, Hertz firmly maintained that the ultimate goal of physics was to reduce all observable physical phenomena to mechanics.

In addition to his theoretical studies in mechanics, Hertz performed research on the discharge of electricity in rarefied gases. Hertz also continued his analysis of Maxwell's theory, publishing two papers in 1890. His experimental and theoretical work put the field of electrodynamics on a much firmer footing. His scientific papers were translated into English and published in three volumes: Electric Waves (1893), Miscellaneous Papers (1896), and Principles of Mechanics (1899).

Hertz suffered from a bone disease during the summer of 1892. Heinrich Hertz died of blood poisoning on 1 January 1894 in Bonn, when not quite 37. His tragic early death occurred after several years of poor health and cut short a brilliant career. He is buried in the Jewish cemetery in Ohlsdorf, Hamburg, Germany.

Achievements

• 

  During Hertz's studies in 1879 Helmholtz suggested that Hertz's doctoral dissertation be on testing Maxwell's theory of electromagnetism, published in 1865, which predicted the existence of electromagnetic waves moving at the speed of light, and predicted that light itself was just such a wave.
  
  Helmholtz had also proposed the "Berlin Prize" problem that year at the Prussian Academy of Sciences for anyone who could experimentally prove an electromagnetic effect in the polarization and depolarization of insulators, something predicted by Maxwell's theory.
  
  Hertz is honored by Japan with a membership in the Order of the Sacred Treasure, which has multiple layers of honor for prominent people, including scientists.
  
  In 1899, only five years after his death, Hamburg honored Heinrich Hertz by naming a street in the district of Uhlenhorst after him.
  
  After the Second World War, Hamburg named the circa 270 meter TV Tower in Rentzelstraße after him, Heinrich-Hertz-Turm. A plaque, on the tower, approximately 20 meters above the ground, carries the inscription: Heinrich Hertz dem Sohn der Stadt Hamburg.
  
  In 1928, the Heinrich-Hertz Institute for Oscillation Research was founded in Berlin.
  
  In 1969, a Heinrich Hertz memorial medal was cast. The IEEE Heinrich Hertz Medal, established in 1987, is "for outstanding achievement sin Hertzian waves … presented annually to an individual for achievements which are theoretical or experimental in nature."
  
  A crater that lies on the far side of the Moon, just behind the eastern limb, is named in his honor.

Works

More photos

• book

  • Electric Waves: Being Researches On the Propagation of Electric Action with Finite Velocity Through Space

    (Electric Waves: Being Researches On the Propagation of El...)

  • Untersuchungen Über Die Ausbreitung Der Elektrischen Kraft

    (This book was originally published prior to 1923 and repr...)

    1923
  • The Principles of Mechanics: Presented in a New Form

    (This classic created a new system of mechanics based on s...)

  • Miscellaneous Papers

    (The present volume consists mainly of the earlier investi...)

Religion

Hertz's father converted from Judaism to Christianity in 1834. His mother's family was a Lutheran pastor's family.

Heinrich Hertz was a Lutheran throughout his life and would not have considered himself Jewish, as his father's family had all converted to Lutheranism when his father was still in his childhood (aged seven) in 1834. His parents, however, were more interested in his education than his religious status.

Politics

It is unknown if Hertz participated in any political movements.

Views

After some months of experimental trials, the apparently unbreakable walls that had frustrated all attempts to prove Maxwell’s theory began crumbling.

It started with a chance observation early in October 1886, when Hertz was showing students electric sparks. Hertz began thinking deeply about sparks and their effects in electric circuits. He began a series of experiments, generating sparks in different ways. He discovered something amazing. Sparks produced a regular electrical vibration within the electric wires they jumped between. The vibration moved back and forth more often every second than anything Hertz had ever encountered before in his electrical work.

He knew the vibration was made up of rapidly accelerating and decelerating electric charges. If Maxwell’s theory were right, these charges would radiate electromagnetic waves which would pass through the air just as light does.

In November 1886 Hertz constructed the apparatus called the oscillator. He applied high voltage a.c. electricity across the central spark-gap, creating sparks.

The sparks caused violent pulses of electric current within the copper wires. These pulses reverberated within the wires, surging back and forth at a rate of roughly 100 million per second.

As Maxwell had predicted, the oscillating electric charges produced electromagnetic waves - radio waves - which spread out through the air around the wires. Some of the waves reached a loop of copper wire 1.5 meters away, producing surges of electric current within it. These surges caused sparks to jump across a spark-gap in the loop.

This was an experimental triumph. Hertz had produced and detected radio waves. He had passed electrical energy through the air from one device to another one located over a meter away. No connecting wires were needed.

Over the next three years, in a series of brilliant experiments, Hertz fully verified Maxwell’s theory. He proved beyond doubt that his apparatus was producing electromagnetic waves, demonstrating that the energy radiating from his electrical oscillators could be reflected, refracted, produce interference patterns, and produce standing waves just like light.

Hertz’s experiment’s proved that radio waves and light waves were part of the same family, which today we call the electromagnetic spectrum.

The waves Hertz first generated in November 1886 quickly changed the world. By 1896 Guglielmo Marconi had applied for a patent for wireless communications. By 1901 he had transmitted a wireless signal across the Atlantic Ocean from Britain to Canada.

In 1887, as part of his work on electromagnetism, Hertz reported a phenomenon that had enormous implications for the future of physics and our fundamental understanding of the universe. It came to be known as the photoelectric effect. He shone an ultraviolet light on electrically charged metal, observing that the UV light seemed to cause the metal to lose its charge faster than otherwise. He wrote the workup, published it in Annalen der Physik, and left it for others to pursue. It would have been a fascinating phenomenon for Hertz himself to investigate, but he was too wound up in his Maxwell project at the time. Experimenters rushed to investigate the new phenomenon Hertz had announced.

The importance of Heinrich Hertz’s research for the development of physics in the early twentieth century was well summarized in a letter of Ludwig Boltzmann to Hermann von Helmholtz on January 6, 1894, just a few days after Hertz’s death: "One should emphasize the extraordinary import of Hertz’s discoveries in relation to our whole concept of Nature, and the fact that beyond a doubt they have pointed out the only true direction that investigation can take for many years to come."

Quotations: "One cannot escape the feeling that these mathematical formulas have an independent existence and an intelligence of their own, that they are wiser than we are, wiser even than their discoverers."

"… day by day I grow more aware of how useless I remain in this world."

"I grow increasingly aware, and in more ways than expected, that I am at the center of my own field; and whether it be folly or wisdom, it is a very pleasant feeling."

"I cannot tell you how much more satisfaction it gives me to gain knowledge for myself and for others directly from nature, rather than to be merely learning from others and myself alone."

Personality

When Hertz died, Sir Oliver Lodge gave Hertz credit for accomplishing that the great English physicists of the time were unable to do. It was not hard to give Hertz credit: "Not only had he established the validity of Maxwell's theorems, he had done so with a winning modesty." "He was a noble man," said one eulogist in 1894, "who had the singular good fortune to find many admirers, but none to hate or envy him; those who came into personal contact with him were struck by his modesty and charmed by his amiability. He was a true friend to his friends, a respected teacher to his students, who had begun to gather around him in large numbers, some of them coming from great distances; and to his family a loving husband and father."

Physical Characteristics: At the age of 35 Hertz became very ill, suffering severe migraines. Doctors thought he had an infection. They performed a series of operations, but Hertz continued to deteriorate.

Quotes from others about the person

• "He was a noble man, who had the singular good fortune to find many admirers, but none to hate or envy him; those who came into personal contact with him were struck by his modesty and charmed by his amiability. He was a true friend to his friends, a respected teacher to his students, who had begun to gather around him in large numbers, some of the coming from great distances; and to his family a loving husband and father."

Interests

• languages, architecture, engineering

Connections

In 1886, Hertz married Elisabeth Doll, the daughter of Dr. Max Doll, a lecturer in geometry at Karlsruhe. They had two daughters: Johanna, born on 20 October 1887, and Mathilde, born on 14 January 1891, who went on to become a notable biologist.

Father:

Gustav Ferdinand Hertz

Mother:

Anna Elisabeth Pfefferkorn

Spouse:

Elisabeth Hertz

Daughter:

Johanna Hertz

Daughter:

Mathilde Hertz

teacher:

Gustav R. Kirchhoff

teacher:

Hermann von Helmholtz

Student:

Vilhelm Bjerknes

References

• The work of Hertz and some of his successors
• The Creation of Scientific Effects: Heinrich Hertz and Electric Waves
• Heinrich Hertz: Entdecker der Radiowellen
• Heinrich Hertz: Classical Physicist, Modern Philosopher
• Heinrich Hertz: Eine Biographie
• Heinrich Hertz: A Short Life