Talk:Heinrich Hertz

Bose
Adding J.C. Bose's name here, as one of the person influenced by Henrich Hertz:

''Hertz's proof of the existence of airborne electromagnetic waves led to an explosion of experimentation with this new form of electromagnetic radiation, which was called "Hertzian waves" until around 1910 when the term "radio waves" became current. Within 10 years researchers such as Oliver Lodge, Ferdinand Braun, and Guglielmo Marconi employed radio waves in the first wireless telegraphy radio communication systems, leading to radio broadcasting, and later television.''

Considering that 1894 is an IEEE milestone Millimeter-wave Communication Experiments by Jagadish Chandra Bose,, I fail to understand this edit undo comment

''(cur | prev) 06:33, 24 February 2019‎ Chetvorno (talk | contribs)‎. . (33,645 bytes) (-25)‎. . (Reverted good faith edits by Kalpak (talk): Actually, Bose did not apply his radio transmitters and receivers to radiotelegraphy communication, but to scientific research (TW))'' Kalpak (talk) 10:04, 21 May 2019 (UTC)Kalpak


 * That edit comment makes perfect sense in the context of the edit. You had added Bose to a sentence about radio telegraphy.  Try to re-do it more appopriately. Dicklyon (talk) 13:54, 21 May 2019 (UTC)


 * Yes, Bose was part of the first generation of radio researchers, including Hertz, Lord Rutherford, Frederick Trouton, and Augusto Righi, who were mainly interested in radio waves as a scientific phenomenon, and largely failed to foresee its possibilities as a communication technology. Bose built a microwave spectrometer and did a lot of research into the waves' properties,  and in a demonstration transmitted microwaves over a short distance to ignite gunpowder by remote control, but he didn't attempt to develop a practical radio communication system, as Lodge, Braun, and Marconi did.  That's why I removed the name from that sentence.  I wouldn't mind an appropriate mention of Bose's contributions. --ChetvornoTALK 20:07, 21 November 2019 (UTC)

Uncited material in need of citations
I am moving the following uncited material here until it can be properly supported with inline citations of reliable, secondary sources, per WP:V, WP:NOR, WP:CS, WP:NOR, WP:IRS, WP:PSTS, et al. This diff shows where it was in the article. Nightscream (talk) 15:45, 15 August 2022 (UTC)

Biography
His mother was Anna Elisabeth Pfefferkorn.

While studying at the Gelehrtenschule des Johanneums in Hamburg, Hertz showed an aptitude for sciences as well as languages, learning Arabic and Sanskrit. He studied sciences and engineering in the German cities of Dresden, Munich and Berlin, where he studied under Gustav R. Kirchhoff and Hermann von Helmholtz. In 1880, Hertz obtained his PhD from the University of Berlin, and for the next three years remained for post-doctoral study under Helmholtz, serving as his assistant. In 1883, Hertz took a post as a lecturer in theoretical physics at the University of Kiel. In 1885, Hertz became a full professor at the University of Karlsruhe.

In 1886, Hertz married Elisabeth Doll, the daughter of 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. During this time Hertz conducted his landmark research into electromagnetic waves.

Hertz took a position of Professor of Physics and Director of the Physics Institute in Bonn on 3 April 1889, a position he held until his death. During this time he worked on theoretical mechanics with his work published in the book Die Prinzipien der Mechanik in neuem Zusammenhange dargestellt (The Principles of Mechanics Presented in a New Form), published posthumously in 1894.

Electromagnetic waves
In 1864 Scottish mathematical physicist James Clerk Maxwell proposed a comprehensive theory of electromagnetism, now called Maxwell's equations. Maxwell's theory predicted that coupled electric and magnetic fields could travel through space as an "electromagnetic wave". Maxwell proposed that light consisted of electromagnetic waves of short wavelength, but no one had been able to prove this, or generate or detect electromagnetic waves of other wavelengths.

He used a dipole antenna consisting of two collinear one-meter wires with a spark gap between their inner ends, and zinc spheres attached to the outer ends for capacitance, as a radiator. The antenna was excited by pulses of high voltage of about 30 kilovolts applied between the two sides from a Ruhmkorff coil. He received the waves with a resonant single-loop antenna with a micrometer spark gap between the ends. This experiment produced and received what are now called radio waves in the very high frequency range.

When an induction coil applied a high voltage between the two sides, sparks across the spark gap created standing waves of radio frequency current in the wires, which radiated radio waves. The frequency of the waves was roughly 50 MHz, about that used in modern television transmitters.]]

In the apparatus Hertz used, the electric and magnetic fields radiated away from the wires as transverse waves. Hertz had positioned the oscillator about 12 meters from a zinc reflecting plate to produce standing waves. Each wave was about 4 meters long. Using the ring detector, he recorded how the wave's magnitude and component direction varied. Hertz measured Maxwell's waves and demonstrated that the velocity of these waves was equal to the velocity of light. The electric field intensity, polarization and reflection of the waves were also measured by Hertz. These experiments established that light and these waves were both a form of electromagnetic radiation obeying the Maxwell equations. Hertz may not have been the first to come across the phenomenon of radio waves - David Edward Hughes may have detected their existence nine years earlier but did not publish his findings.

Cathode rays
In 1892, Hertz began experimenting and demonstrated that cathode rays could penetrate very thin metal foil (such as aluminium). Philipp Lenard, a student of Heinrich Hertz, further researched this "ray effect". He developed a version of the cathode tube and studied the penetration by X-rays of various materials. However, Lenard did not realize that he was producing X-rays. Hermann von Helmholtz formulated mathematical equations for X-rays. He postulated a dispersion theory before Röntgen made his discovery and announcement. It was formed on the basis of the electromagnetic theory of light (Wiedmann's Annalen, Vol. XLVIII). However, he did not work with actual X-rays.

Photoelectric effect
Hertz helped establish the photoelectric effect (which was later explained by Albert Einstein) when he noticed that a charged object loses its charge more readily when illuminated by ultraviolet radiation (UV). In 1887, he made observations of the photoelectric effect and of the production and reception of electromagnetic (EM) waves, published in the journal Annalen der Physik. His receiver consisted of a coil with a spark gap, whereby a spark would be seen upon detection of EM waves. He placed the apparatus in a darkened box to see the spark better. He observed that the maximum spark length was reduced when in the box. A glass panel placed between the source of EM waves and the receiver absorbed UV that assisted the electrons in jumping across the gap. When removed, the spark length would increase. He observed no decrease in spark length when he substituted quartz for glass, as quartz does not absorb UV radiation. Hertz concluded his months of investigation and reported the results obtained. He did not further pursue investigation of this effect, nor did he make any attempt at explaining how the observed phenomenon was brought about.

Contact mechanics
...on what was to become known as the field of contact mechanics, which proved to be an important basis for later theories in the field. Joseph Valentin Boussinesq published some critically important observations on Hertz's work, nevertheless establishing this work on contact mechanics to be of immense importance. His work basically summarises how two axi-symmetric objects placed in contact will behave under loading, he obtained results based upon the classical theory of elasticity and continuum mechanics. The most significant flaw of his theory was the neglect of any nature of adhesion between the two solids, which proves to be important as the materials composing the solids start to assume high elasticity. It was natural to neglect adhesion at the time, however, as there were no experimental methods of testing for it.

Hertz also described the "Hertzian cone", a type of fracture mode in brittle solids caused by the transmission of stress waves.

Treatment by the Third Reich
His family was also persecuted for their non-Aryan status. Hertz's youngest daughter, Mathilde, lost a lectureship at Berlin University after the Nazis came to power and within a few years she, her sister, and their mother left Germany and settled in England.

The section describes the Nazi regime as a political movement that "classified people by race instead of by religious affiliation"... Excuse me but why is the latter proposed as the alternative here? Wouldn't the alternative here be NOT classifying (implied to mean discriminating between) people based on any such component of identity, be it race or religion?71.65.237.6 (talk) 02:28, 27 November 2022 (UTC)

Legacy and honors
The SI unit hertz (Hz) was established in his honor by the International Electrotechnical Commission in 1930 for frequency, an expression of the number of times that a repeated event occurs per second. It was adopted by the CGPM (Conférence générale des poids et mesures) in 1960, officially replacing the previous name, "cycles per second" (cps).

In 1928 the Heinrich-Hertz Institute for Oscillation Research was founded in Berlin. Today known as the Fraunhofer Institute for Telecommunications, Heinrich Hertz Institute, HHI.

In 1980, in Italy a High School called "Istituto Tecnico Industriale Statale Heinrich Hertz" was founded in the neighborhood of Cinecittà Est, in Rome.

The Submillimeter Radio Telescope at Mt. Graham, Arizona, constructed in 1992 is named after him.

A crater that lies on the far side of the Moon, just behind the eastern limb, is named in his honor. The Hertz market for radio electronics products in Nizhny Novgorod, Russia, is named after him. The Heinrich-Hertz-Turm radio telecommunication tower in Hamburg is named after the city's famous son.

"a regime that classified people by "race" instead of religious affiliation".

First of all, I think Nazis classified people by both. Jews were persecuted for both being non-Aryan and Jew. They were called Jews by Nazis, not non-Aryans.

Secondly, Is it correct to classify people by their religion that the article says Nazis classified people by their races instead of their religions? Aminabzz (talk) 14:18, 24 June 2023 (UTC)

Classification
"A regime that classified people by race instead of religious affiliation". First of all, I think Nazis classified people by both. Jews were persecuted for both being non-Aryan and Jew. They were called Jews by Nazis, not non-Aryans. Secondly, Is it correct to classify people by their religion that the article says Nazis classified people by their races instead of their religions? Aminabzz (talk) 22:01, 5 August 2023 (UTC)

"Hertz (person)" listed at Redirects for discussion
The redirect [//en.wikipedia.org/w/index.php?title=Hertz_(person)&redirect=no Hertz (person)] has been listed at redirects for discussion to determine whether its use and function meets the redirect guidelines. Readers of this page are welcome to comment on this redirect at  until a consensus is reached. Presidentman talk · contribs (Talkback) 21:21, 13 January 2024 (UTC)

Figures party
Figures are all over the place. Can we decide which to keep and which to center? ReyHahn (talk) 15:56, 1 March 2024 (UTC)