Heinrich Rudolf Hertz
was a German physicist who first conclusively proved the existence of the electromagnetic waves predicted by James Clerk Maxwell's equations of electromagnetism. The unit of frequency, cycle per second, was named the "hertz" in his honor Born:February 22, 1857, Hamburg, Germany Died:January 1, 1894, Bonn, Germany Nationality: German, a westman |
The Heinrich Hertz Story (Video Overview)
In the ascent of Western Civilzation, its discoveries, its inventions, from gas lamps and horse drawn carriages to the exploration of the universe is the story of men, Westmen. Issac Newton once remarked: if I have seen further than others it is because I have stood upon the shoulders of giants.
James Clerk Maxwell, an English scientist, developed a scientific theory to explain electromagnetic waves. He noticed that electrical fields and magnetic fields can couple together to form electromagnetic waves. Neither an electrical field, for example, like the static which forms when you rub your feet on a carpet, nor a magnetic field like the one that holds a magnet onto your refrigerator will go anywhere by themselves. But, Maxwell discovered that a CHANGING magnetic field will induce a CHANGING electric field and vice-versa.
An electromagnetic wave exists when the changing magnetic field causes a changing electric field, which then causes another changing magnetic field, and so on forever. Unlike a STATIC field, a wave cannot exist unless it is moving. Once created, an electromagnetic wave will continue on forever unless it is absorbed by matter.
In 1884 John Henry Poynting proved that if electro-magnetic waves existed, they would be able to transmit both energy and momentum to a material which intercepted them. This would be a test of the physical reality of electromagnetic waves. The energy is evident in any object heated by bright sunlight, and the momentum showed itself in the pressure of sunlight measured by Lebedev a Russian in 1902. This pressure of sun light is under consideration for deep space propulsion through the use of solar sails. Unfortunately Maxwell died of stomach cancer in 1879, what else he may have contributed, had he lived to an older age.
Heinrich Rudolf Hertz is one of the giants of Western Civilization. He was a German physicist, the first to conclusively prove the existence of the electromagnetic waves as predicted by James Clerk Maxwell's equations of electromagnetism. The unit of frequency, the cycle per second, was named the "hertz" in his honor.
Heinrich Rudolf Hertz
Born: 22 February 1857: Hamburg, German Confederation
Died: 1 January 1894 (aged 36) Bonn Germany
At age six, Heinrich Hertz began his education at the Dr. Wichard Lange School in Hamburg. This was a private school for boys run 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 at the top of the class. Heinrich enjoyed his time at school, and indeed he was top of his class.
Dr. Lange’s school did not teach the Greek and Latin 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 school, 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 at age 11.
The young Hertz changed is mind several times with regard to his field of study which later caused him to remark “… day by day I grow more aware of how useless I remain in this world.”
At age 15, Heinrich left Dr. Lange’s school to be home schooled. Home schooled? …. Yes, Home schooled.
He had decided that perhaps he would like to go to university after all. Now he received tutoring in Greek, Latin, and other languages to prepare for the university entrance exams. The young Heinrich discovered that in addition to a natural talent for languages he also had a natural instinct for mathematics and science.
He also had a colossal appetite for hard work. His mother noted: That when he was surrounded by his books studying, nothing could disturb him or pull him away. By day Hertz studied and 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 he built to do his own physics and chemistry experiments. In spring 1876, aged 19, he moved to Dresden, to study engineering.
Then At age 21, Hertz moved to Berlin and began working in the laboratories of the great German physicist Hermann von Helmholtz. Helmholtz immediately recognized the enormous talent Hertz possessed.
Helmholtz asked Hertz to compete for a prize offered by the Berlin Academy: verifying James Clerk Maxwell’s theory of electromagnetism.
Hertz declined this project; as he believed that the attempt, with no guarantee of success, would take several years of work. He was ambitious and wanted to publish new results quickly to establish his reputation.
Instead of working for the prize, he carried out a masterful three-month project on electromagnetic induction. He wrote this up as a thesis. In February 1880, at the age of 23, his thesis brought him the award of a doctorate in physics. Helmholtz quickly appointed him as an assistant professor. With Helmholtz’s support, Hertz became a lecturer in mathematical physics at the University of Kiel. This position, theoretical rather than experimental. And while at Kiel Hertz began to get to immerse himself in Maxwell’s equations, writing in his diary:
“Hard at Maxwellian electromagnetism in the evening. Nothing but electromagnetism.”
“From the start, Maxwell’s theory was the most elegant of all… the fundamental hypothesis of Maxwell’s theory contradicted the usual views, and was not supported by evidence from decisive experiments.”
Hertz began to ponder what type of experiment could definitively prove the existence of Maxwell’s electromagnetic waves.
In March 1885, wanting to return to experimental physics, Hertz moved to the University of Karlsruhe. He was 28 years old at the time, he had secured a full professorship at Karlsruhe. He was actually offered two other full professorships, a sign of his flourishing reputation. But He chose Karlsruhe because it had the best laboratory facilities.
In his lectures to students Hertz demonstrated that electricity could produce sparks. In the Fall of 1886 . 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 wires. And the sparks jumped between the wires. 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 air just as light does.
That the electron was the carrier of these charges was not known at this time. JJ Thompson was about 18 years away from demonstrating this fact.
In November 1886 Hertz constructed the apparatus he would use to create and detect electromagnetic waves.
He applied high voltage alternating current . electricity across a central 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 an air-gap in the loop.
This was an amazing experimental triumph. Hertz had produced and detected radio waves. He had passed electrical energy through the air from one device to another located over a meter away with no connecting wires.
Taking it Further
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.
During this period of experimentation Hertz invented the parabolic dish antenna. He used cylindrical parabolic reflectors with spark-excited dipole antennas at their focus for both transmitting and receiving during his historic experiments Yes, basicallly the same type of dish antenna that is in wide commercial use today by satellite broadcasters.
Hertz’s experiment’s proved that radio waves and light waves were part of the same family, which today we call the electromagnetic spectrum.
In 1892, Hertz was diagnosed with an infection (after a bout of severe migraines) and underwent surgery to treat the illness. He died due to complications from the surgery.
Hertz's wife, Elisabeth Hertz did not remarry. He was survived by two daughters, Johanna who died in 1967. and Mathilde who died in 1975. Hertz's daughters never married and he tragically has no descendants.
In the ascent of Western Civilzation, its discoveries, its inventions, from gas lamps and horse drawn carriages to the exploration of the universe is the story of men, Westmen. Issac Newton once remarked: if I have seen further than others it is because I have stood upon the shoulders of giants.
James Clerk Maxwell, an English scientist, developed a scientific theory to explain electromagnetic waves. He noticed that electrical fields and magnetic fields can couple together to form electromagnetic waves. Neither an electrical field, for example, like the static which forms when you rub your feet on a carpet, nor a magnetic field like the one that holds a magnet onto your refrigerator will go anywhere by themselves. But, Maxwell discovered that a CHANGING magnetic field will induce a CHANGING electric field and vice-versa.
An electromagnetic wave exists when the changing magnetic field causes a changing electric field, which then causes another changing magnetic field, and so on forever. Unlike a STATIC field, a wave cannot exist unless it is moving. Once created, an electromagnetic wave will continue on forever unless it is absorbed by matter.
In 1884 John Henry Poynting proved that if electro-magnetic waves existed, they would be able to transmit both energy and momentum to a material which intercepted them. This would be a test of the physical reality of electromagnetic waves. The energy is evident in any object heated by bright sunlight, and the momentum showed itself in the pressure of sunlight measured by Lebedev a Russian in 1902. This pressure of sun light is under consideration for deep space propulsion through the use of solar sails. Unfortunately Maxwell died of stomach cancer in 1879, what else he may have contributed, had he lived to an older age.
Heinrich Rudolf Hertz is one of the giants of Western Civilization. He was a German physicist, the first to conclusively prove the existence of the electromagnetic waves as predicted by James Clerk Maxwell's equations of electromagnetism. The unit of frequency, the cycle per second, was named the "hertz" in his honor.
Heinrich Rudolf Hertz
Born: 22 February 1857: Hamburg, German Confederation
Died: 1 January 1894 (aged 36) Bonn Germany
At age six, Heinrich Hertz began his education at the Dr. Wichard Lange School in Hamburg. This was a private school for boys run 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 at the top of the class. Heinrich enjoyed his time at school, and indeed he was top of his class.
Dr. Lange’s school did not teach the Greek and Latin 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 school, 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 at age 11.
The young Hertz changed is mind several times with regard to his field of study which later caused him to remark “… day by day I grow more aware of how useless I remain in this world.”
At age 15, Heinrich left Dr. Lange’s school to be home schooled. Home schooled? …. Yes, Home schooled.
He had decided that perhaps he would like to go to university after all. Now he received tutoring in Greek, Latin, and other languages to prepare for the university entrance exams. The young Heinrich discovered that in addition to a natural talent for languages he also had a natural instinct for mathematics and science.
He also had a colossal appetite for hard work. His mother noted: That when he was surrounded by his books studying, nothing could disturb him or pull him away. By day Hertz studied and 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 he built to do his own physics and chemistry experiments. In spring 1876, aged 19, he moved to Dresden, to study engineering.
Then At age 21, Hertz moved to Berlin and began working in the laboratories of the great German physicist Hermann von Helmholtz. Helmholtz immediately recognized the enormous talent Hertz possessed.
Helmholtz asked Hertz to compete for a prize offered by the Berlin Academy: verifying James Clerk Maxwell’s theory of electromagnetism.
Hertz declined this project; as he believed that the attempt, with no guarantee of success, would take several years of work. He was ambitious and wanted to publish new results quickly to establish his reputation.
Instead of working for the prize, he carried out a masterful three-month project on electromagnetic induction. He wrote this up as a thesis. In February 1880, at the age of 23, his thesis brought him the award of a doctorate in physics. Helmholtz quickly appointed him as an assistant professor. With Helmholtz’s support, Hertz became a lecturer in mathematical physics at the University of Kiel. This position, theoretical rather than experimental. And while at Kiel Hertz began to get to immerse himself in Maxwell’s equations, writing in his diary:
“Hard at Maxwellian electromagnetism in the evening. Nothing but electromagnetism.”
“From the start, Maxwell’s theory was the most elegant of all… the fundamental hypothesis of Maxwell’s theory contradicted the usual views, and was not supported by evidence from decisive experiments.”
Hertz began to ponder what type of experiment could definitively prove the existence of Maxwell’s electromagnetic waves.
In March 1885, wanting to return to experimental physics, Hertz moved to the University of Karlsruhe. He was 28 years old at the time, he had secured a full professorship at Karlsruhe. He was actually offered two other full professorships, a sign of his flourishing reputation. But He chose Karlsruhe because it had the best laboratory facilities.
In his lectures to students Hertz demonstrated that electricity could produce sparks. In the Fall of 1886 . 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 wires. And the sparks jumped between the wires. 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 air just as light does.
That the electron was the carrier of these charges was not known at this time. JJ Thompson was about 18 years away from demonstrating this fact.
In November 1886 Hertz constructed the apparatus he would use to create and detect electromagnetic waves.
He applied high voltage alternating current . electricity across a central 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 an air-gap in the loop.
This was an amazing experimental triumph. Hertz had produced and detected radio waves. He had passed electrical energy through the air from one device to another located over a meter away with no connecting wires.
Taking it Further
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.
During this period of experimentation Hertz invented the parabolic dish antenna. He used cylindrical parabolic reflectors with spark-excited dipole antennas at their focus for both transmitting and receiving during his historic experiments Yes, basicallly the same type of dish antenna that is in wide commercial use today by satellite broadcasters.
Hertz’s experiment’s proved that radio waves and light waves were part of the same family, which today we call the electromagnetic spectrum.
In 1892, Hertz was diagnosed with an infection (after a bout of severe migraines) and underwent surgery to treat the illness. He died due to complications from the surgery.
Hertz's wife, Elisabeth Hertz did not remarry. He was survived by two daughters, Johanna who died in 1967. and Mathilde who died in 1975. Hertz's daughters never married and he tragically has no descendants.