Talk:Heinrich Hertz

Different interpretation of Hertz's experiment

I have not found any work critical to Hertz's work. It seems to me that Hertz was under the influence of Maxwell's theory and purposefully interpreted his experiments to fit, and give false support, to Maxwell's theory. If the editor of Wikipedia's article on Heinrich Hertz deems useful, I would invite him to read this article ( http://vixra.org/pdf/1511.0065v1.pdf ) in which it is shown that Hertz was not correct to claim that he detected the electric and the magnetic components of the radio wave produced in his experiments - and include a reference to this in the Wikipedia article. The main point is: Hertz detected only magnetic waves through electromagnetic induction occurring in his circular wire detector and no reason can be given for believing that he was detecting any electric wave. The main argument is: Hertz held his detector vertically at all times but used a double standard when interpreting the cause of the sparks at the gap of his detector: on one hand he used electromagnetic induction (for the magnetic component, dotted wave in his diagram), but on the other hand claimed electric field (for the electric component, full line in his diagram). Hertz's fallacy is: when you hold the detector vertically, in both situations you get electromagnetic induction no matter how you orient the gap of the detector - in that position the effect of electromagnetic induction is maximum (Hertz himself said the magnetic field lines are perpendicular to the plane of the detector in the vertical position he used in his experiments). Please excuse me if this discussion was not allowed here, I only thought this might be relevant. (Idnwiki (talk) 16:59, 12 November 2015 (UTC)Ionel DINUIdnwiki (talk) 16:59, 12 November 2015 (UTC)

Thank you for bringing these intriguing questions here. Regardless of the merits of the arguments presented, Wikipedia policy prohibits including original research in articles; please see WP:NOR. Self-published work, as yours appears to be, is not regarded as being reliably sourced. For it to be considered for inclusion in the article, it would first have to be published in a third-party source, per WP:RS. Hertz1888 (talk) 21:57, 12 November 2015 (UTC)

And publications by a single researcher alone are not enough. It would also have to be mentioned by a WP:secondary source, such as a survey article or a textbook, see WP:PSTS. --Chetvorno^TALK 22:54, 12 November 2015 (UTC)

I appreciate DINUIdnwiki's iconoclastic views of the work of Heinrich Rudolph Hertz! Maybe there could be a section in this article like I have seen in other Wiki articles titled Criticisms?

In the article " ... On the false Electric Waves of delusional Heinrich Hertz" it was stated,

"I will also argue that the theoretical claim that radio waves are composed of oscillating electric and magnetic fields has never been verified by experiment – the truth is that Hertz interpreted his experiments to agree with Maxwell’s theory."  

If you are Brave and Strong, I challenge you to do the following experiment that I have done repeatedly.

In your motor vehicle that has an eighty something centimeter spike antenna on the fender, tune in Your favorite Medium Wave AM radio station . Enjoy the programming for a few minutes while you look at the electric spike sticking out near the bonnet. Also consider that the length of the Launcher of those radio waves is regulated by the FCC to a certain percentage of the frequency of that wave (assuming the wave travels at 299 792 458 meters per second (to the nearest meter), the launcher would be near a quarter wave in height and vertical over a counterpoise). The counterpoise dimensions and number of radials are also regulated to ensure efficient launching of the waves.

See: Electronic Code of Federal Regulations part 47

and: Graphic of Formula See also: Graphic of Antenna

both are very boring and tedious documents from the Code of Federal Regulations part 47, which is the CFR for the FCC

Ponder again the electric spike sticking out of the fender.

Now go inside and tune in that same radio station on a portable transistor radio that has no electric spike sticking out of it. I will provide you with that radio if you do not have one, I WILL NOT however provide you with a Motor Vehicle if you do not have one! :-)

Listen for a while and enjoy the programming on Your favorite Medium Wave Amplitude Modulated radio station and consider this (Open the radio with a screwdriver if you need additional proof). The antenna inside the portable AM receiver consists of a coil of wire wrapped around a ferrite core resonate at the frequency of reception, a magnet antenna. This is a very different device than the spike on the motor vehicle. See: Google Pix of Ferrite Antennas which shows various magnetic antennas for Medium Wave AM reception.

After I have repeated this experiment on numerous occasions, I can only conclude that:

The statement "... the theoretical claim that radio waves are composed of oscillating electric and magnetic fields has never been verified by experiment ..." is not correct as demonstrated by the above outlined experiment.

Please correct me if I am wrong!

GeorgeV73GT (talk) 00:23, 6 October 2016 (UTC)

PS. It is well accepted in the Electronic Engineering Field that Electromagnetic Waves consist of an electrical component with an orthogonal magnet component. Does the wide acceptance of this make it true? NO, OF COURSE NOT! But the results of the above outlined experiment would lead a reasonable person to conclude that it is true that electromagnetic waves consist of an electric component and a magnetic component. YMMV. There is a lot of information at the Institue of Electrical and Electronic Engineers

@ GeorgeV73GT GeorgeV73GT (talk) Thank you for your comments. I have more than once contemplated such ferrite antennas mounted directly on the PCB inside a transistor radio. But then this type of antenna comes only to support the idea of the article (which is that radio waves are magnetic only, and do not have an electric component), reception happening through electromagnetic induction (varying magnetic field) in the coil wound on the ferrite core of the antenna. The electrical component of the radio wave (if existent at all) does not play any role in the production of electric signals in the coil. If the radio wave had an electric component, it would be possible to detect radio waves with antennas in the form capacitors only, which is not the case. So again, what Hertz did in his experiments was to detect the radio waves through electromagnetic induction only, and this would make one conclude that radio waves are magnetic only. But probably because Hertz was working with Maxwell's theory (which he believed to be true simply because it was the only theory available then stating that there are waves produced electromagnetically that travel with the speed of light), it seems to me that he somehow forced the interpretation of his own experiments to agree with Maxwell's theory; thus Hertz made up an explanation that, in radio waves, besides the magnetic component (which is obviously present), there is also an electric component (which I believe is not true) just to make his experiments look as if they proved Maxwell's theory true.Idnwiki (talk) 19:38, 3 February 2017 (UTC)

Removal of paragraph on radio wave/light analogy

I added a paragraph to the article helping to explain why Hertz did not realize the potential practical uses of radio waves

Part of the reason for this was that Hertz's insight was limited by the analogy between radio waves and light. He believed that like light, radio waves only traveled in straight lines, and so their use as a communication medium would be limited by the horizon to a few miles.

This was recently removed by an editor with the edit comment: "it's not an analogy, they are exactly the same and do travel in straight lines -- I think you mean "didn't anticipate ionospheric reflection"

The first over-the-horizon transmission was by ground waves, not skywaves. Today we are used to the idea that radio waves can propagate beyond the horizon by two methods, ground waves which follow the contour of the Earth, and skywaves which reflect from the ionosphere. But the waves Hertz generated were in the VHF and UHF bands, which did not propagate by these methods, only line-of-sight. Even if he had generated lower frequencies, they wouldn't have traveled much beyond the horizon because he was using horizontal dipole antennas. Ground waves require vertically polarized antennas. Over-the-horizon radio propagation was only achieved by Marconi after he invented the monopole antenna in 1895.

The belief that radio waves traveled in straight lines, originating from the radio wave/light analogy, was held by the first generation of radio scientists: Hertz, FitzGerald, Lodge until Marconi proved them wrong (they even called the first radio receivers "artificial eyes"). In the late 1800s there were already light wave communication methods being used, semaphore and Bell's photophone, which did not require complicated circuits and used the sensitive human eye as a receiver. If radio waves were limited by the horizon like light, as these scientists believed, radio would have no advantage over these simpler communication methods. That's the context of Hertz's comment. @LaurentianShield: The paragraph I added was unsourced; I'll try to find some sources on this. --Chetvorno^TALK 21:26, 13 February 2017 (UTC)

My edit summary that you quote above is from when I restored your paragraph that LaurentianShield removed. I think your point is about right, but I don't find a good source to directly support it. See also the discussion that LaurentianShield started on my talk page (I don't know why he didn't start it here where it belongs). Dicklyon (talk) 21:57, 13 February 2017 (UTC)

OK, I see you've changed it now to his edit summary, and that you've also found the discussion on my page. Dicklyon (talk) 22:14, 13 February 2017 (UTC)

Thanks for catching my error! I think the optical analogy is in The Maxwellians, a great book about the first generation of radio researchers: Hertz, Oliver Lodge, George FitzGerald. Earnest Rutherford, but not much of the text is visible in Google Books. But the role of the optical analogy in limiting innovation is definitely in Hong. It doesn't say specifically that Hertz believed that radio waves were limited by the horizon, but it does say "...the Maxwellian physicists' adherence to optics obscured a telegraphic application of Hertzian waves."(p.7). Marconi, who was not a scientist but an entrepreneur, was inspired by ground-return telegraph systems of the time to try grounding one side of his transmitter (p.21), which enabled him to transmit long distances. "The emphasis on telegraphy separates Marconi from the other physicists and engineers that were working on Hertzian waves; all the others were preoccupied by optical analogies." (p.22) --Chetvorno^TALK 23:26, 13 February 2017 (UTC)

I can check my copy of The Maxwellians on Thursday or so. Dicklyon (talk) 00:11, 15 February 2017 (UTC)

I have a source I cited on Dicklyon's page, which says that the primary reason Hertz did not believe radio was viable for communication was not the line-of-sight issue, but rather because he did not think the waves would have the strength. In order for him to cause the spark to jump in his receiver, he had to focus his waves using what he called "mirrors". There is a fairly clear direct quote, I just don't have it right now. My main concern in any case was to call radio waves an "analogy" with light. In free space they are identical and both travel is straight lines orthogonal to the E-M fields. Quasi-guided waves (such as around the earth) can "bend" of course, from a variety of factors. I would like to see any wording not muddle this point to new readers who might not understand the subtlety. Meanwhile, when I find the quote I am referring to, I will provide it. LaurentianShield (talk) 23:40, 13 February 2017 (UTC)

Here is the quote by Harold I. Sharlin, in The Making of the Electrical Age who further goes on to quote Hertz:

Hertz was asked if his discovery could be used for telegraphy. "If you could construct a mirror as large as a continent, you might succeed with suche experiments," he answered, "but it is impracticable to do anything with ordinary mirrors, as there would not be the least effect observable." He mistakenly believed that waves had to be focused to travel any distance.

Sharlin cites Rupert W. Maclaurin, Invention and Innovation in the Radio Industry as his source. Note that Sharlin interprets Hertz to be speaking about strength (distance), an interpretation which I assume he arrives at from Maclaurin.

With respect to the line-of-site issue, if it is worthy of mention I hope it is obvious that I agree radio EM propagation at RF is different that optical frequency propagation in and around media, I would just like to be more precise about it one way or the other -- light after all bends when it is guided, even on the Earth. My guess is Marconi anticipated that RF somehow does something similar, or else he would not have dared with the trans-Atlantic transmission.

LaurentianShield (talk) 00:47, 14 February 2017 (UTC)

Its interesting to see Hertz did say something about wireless telegraphy, didn't know that and it should probably be added to the article. Beyond Hertz (may be off topic) - the reason not to develop radio-telegraphy before Marconi was "wire was cheap". Radio waves could not be detected over 1/2 mile (according to Lodge), they required expensive and delicate lab equipment to even detect them, and since they could only send a signal to something at a short visual range, why not just lay wire, or use a signal light or flag if it was a ship at sea. The only real use they could see for adapting such an arcane laboratory experiment to telegraphy was, "what if you had a ship lost in fog looking for a lighthouse, can't use a wire and can't use a visual signal. Yep, maybe that is an occasion it would be worthwhile to have radio based communication" (Hong, page 8 and 17). Fountains of Bryn Mawr (talk) 20:32, 14 February 2017 (UTC)

All of those applications you mention are short range, within the visual horizon. The background assumption of all these educated physicists was that of course radio waves couldn't propagate much beyond the horizon regardless of their power, because they travel in straight lines, because light does. So there wasn't much incentive to increase the power. If Hertz or his contemporaries had the slightest inkling in 1887 that radio waves could travel transatlantic distances, they would have been all over it. But they missed it, because they were hung up on the optical analogy, where Marconi wasn't. Yes, if it was limited to line-of-sight, radio was not much of an improvement over wire. But if it can travel 3000 miles around the curve of the Earth? BIG improvement. --Chetvorno^TALK 23:11, 14 February 2017 (UTC)

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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 [1], 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. --Chetvorno^TALK 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)

Extended content

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. Scientific work 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.