Milestone-Proposal:First generation and experimental proof of electromagnetic waves 1886-1888.

From ETHW

Docket #:2013-26

This proposal has been submitted for review.


Is the achievement you are proposing more than 25 years old? Yes

Is the achievement you are proposing within IEEE’s fields of interest? (e.g. “the theory and practice of electrical, electronics, communications and computer engineering, as well as computer science, the allied branches of engineering and the related arts and sciences” – from the IEEE Constitution) Yes

Did the achievement provide a meaningful benefit for humanity? Yes

Was it of at least regional importance? Yes

Has an IEEE Organizational Unit agreed to pay for the milestone plaque(s)? Yes

Has an IEEE Organizational Unit agreed to arrange the dedication ceremony? Yes

Has the IEEE Section in which the milestone is located agreed to take responsibility for the plaque after it is dedicated? Yes

Has the owner of the site agreed to have it designated as an Electrical Engineering Milestone? Yes


Year or range of years in which the achievement occurred:

1886-1888

Title of the proposed milestone:

First Generation and Experimental Proof of Electromagnetic Waves, 1886-1888.

Plaque citation summarizing the achievement and its significance:

In this building, Heinrich Hertz first verified Maxwell's equations and prediction of electromagnetic waves in 1886-1888. He observed the reflection, refraction and polarization of the waves and, moreover, the equality of their velocity of propagation with the velocity of light. His 450 MHz transmitter and receiver demonstrated the fundamentals of high-frequency technology.

In what IEEE section(s) does it reside?

IEEE Germany Section

IEEE Organizational Unit(s) which have agreed to sponsor the Milestone:

IEEE Organizational Unit(s) paying for milestone plaque(s):

Unit: IEEE Germany Section
Senior Officer Name: Senior officer name masked to public

IEEE Organizational Unit(s) arranging the dedication ceremony:

Unit: IEEE Germany Section
Senior Officer Name: Senior officer name masked to public

IEEE section(s) monitoring the plaque(s):

IEEE Section: IEEE Germany Section
IEEE Section Chair name: Section chair name masked to public

Milestone proposer(s):

Proposer name: Proposer's name masked to public
Proposer email: Proposer's email masked to public

Proposer name: Proposer's name masked to public
Proposer email: Proposer's email masked to public

Please note: your email address and contact information will be masked on the website for privacy reasons. Only IEEE History Center Staff will be able to view the email address.

Street address(es) and GPS coordinates of the intended milestone plaque site(s):

Kaiserstrasse 12, 76131 Karlsruhe, Germany 49.009515, 8.41233 (Heinrich-Hertz-Auditorium)

Describe briefly the intended site(s) of the milestone plaque(s). The intended site(s) must have a direct connection with the achievement (e.g. where developed, invented, tested, demonstrated, installed, or operated, etc.). A museum where a device or example of the technology is displayed, or the university where the inventor studied, are not, in themselves, sufficient connection for a milestone plaque.

Please give the address(es) of the plaque site(s) (GPS coordinates if you have them). Also please give the details of the mounting, i.e. on the outside of the building, in the ground floor entrance hall, on a plinth on the grounds, etc. If visitors to the plaque site will need to go through security, or make an appointment, please give the contact information visitors will need.

The intended site on the campus of Karlsruhe Institute of Technology (KIT) is the Heinrich-Hertz-Auditorium, where Heinrich Hertz performed his experiments. There is a sculpture of Heinrich Hertz on the site (see supporting material, Fig.1).

Are the original buildings extant?

Yes

Details of the plaque mounting:

The plaque shall be mounted outside the Heinrich–Hertz-Auditorium next to the sculpture of Heinrich Hertz.

How is the site protected/secured, and in what ways is it accessible to the public?

The plaque site on KIT campus is open to the public.

Who is the present owner of the site(s)?

KIT (Karlsruhe Institute of Technology)

A letter in English, or with English translation, from the site owner(s) giving permission to place IEEE milestone plaque on the property:

File:Hertz Nom KIT Agreement.pdf

A letter or email from the appropriate Section Chair supporting the Milestone application:

File:VDE-PS01 V-02-112-FMFG 0186 001.pdf

What is the historical significance of the work (its technological, scientific, or social importance)?

The generation of electromagnetic waves is one link in a chain of historic milestones connected with the names of Michael Faraday, James Clerk Maxwell, Heinrich Hertz and Guglielmo Marconi. Hence, its historic significance is two-sided. Hertz verified Maxwell´s theory against the then prevailing views of electromagnetic phenomena and at the same time he opened for Marconi the gateway to the new world of radio and wireless services.

Based on the work of Jean-Baptiste Biot, Félix Savart and others the prevailing theory – especially on the European continent – interpreted the electromagnetic phenomena as long-range effects passing instantaneously over the space between charges, currents and magnets. This was supported by the fact that Biot-Savart´s force law showed the same spatial structure as Newton´s law. In opposition to this Faraday postulated his conception of short-range effects in electric and magnetic fields, which propagate with a finite velocity through the space. Maxwell presented Faraday´s conception in mathematical form. As a solution of his field equations he obtained electromagnetic waves propagating with the velocity of light. Hence, Maxwell´s theory asserted the existence of electromagnetic waves and the identity of light with them. However, the question whether this forecast is true or false remained unanswered for two decades.

In 1879, initiated by Hermann von Helmholtz, the Academy of Sciences in Berlin, Germany opened a competition for an experimental decision between the two contrary theories of electrodynamics. But only six years later when Hertz left the University of Kiel and became Professor of Physics at the Technische Hochschule Karlsruhe the solution of this problem seemed feasible to him. Here the laboratory facilities including a pair of so-called Ries’s coils were much superior to those at Kiel and he started his experiments. The main problem was how to obtain reactions with very high frequency. He constructed a resonant circuit with both, very small capacitance and inductance by a dipole loaded with two 30 cm diameter spheres made of zinc sheet. The excitation was realized by a spark discharge in the center of the dipole. This arrangement radiated the electromagnetic waves quite well. With a circular wire, a loop antenna, likewise interrupted by a small gap, electromagnetic waves were received and caused a spark discharge. With this configuration Heinrich Hertz was able to detect electromagnetic waves up to a distance of 18 meters. Hertz finally achieved stationary waves with frequencies of 450 MHz by interference of incident and reflected waves. This made it possible to measure the wave length and therewith the velocity of wave propagation. Moreover he could distinguish electric and magnetic fields and their directions, which was the basis for later radio direction finding. (The original apparatus built by Heinrich Hertz is in the Deutsches Museum, Munich in the permanent physics exhibition.)

Although Heinrich Hertz did not foresee the consequences of his experimental results with electromagnetic waves, with his experiments and his invention of radio frequency transmitters and receivers he accomplished the fundamentals of high-frequency technology. His experiments, including the invented equipment, were the basis for RF application for communication and Radar. Guglielmo Marconi, Ferdinand Braun, Christian Hülsmeyer and many others based their technologies and inventions on Heinrich Hertz’s results. And his name was in 1960 adopted for worldwide use as the SI unit name for frequency: Hz.

What obstacles (technical, political, geographic) needed to be overcome?

Hertz had to invent the essential high-frequency equipment to generate and detect electromagnetic waves, that is emitters and receivers for 40 MHz in the beginning and finally 450 MHz.

What features set this work apart from similar achievements?

After the competition for an experimental decision between the opposing theories of electrodynamics had been opened in 1879 by the Academy of Sciences in Berlin, very probably there must have been great interest and diverse attempts to participate in this. Heinrich Hertz himself instantly seized this task. He calculated the necessary prerequisites for successful experiments but at that time he came to a negative result.

Besides this there had been a number of earlier experiments drawing sparks from conductors in the vicinity of electric discharges (see Charles Susskind, Heinrich Hertz: A Short Life), the earliest already prior to the publication of Maxwell´s Treatise in 1873. In 1842 Joseph Henry already noted the oscillatory nature of spark discharge and presumed that light is an electromagnetic phenomenon. In 1870 Wilhelm von Bezold discovered in his experiments on electric discharge that electricity is transmitted along a wire with a finite velocity. In 1875 Thomas Alva Edison refused the electrical nature of the spark phenomenon and supposed a new force behind it. But this hypothesis was in 1876 experimentally disproved by Eli Thompson. In 1879 David Edward Hughes discovered that sparks would generate a radio signal, but did not report this until later. Moreover, Hughes apparently did not properly understand the operation of the transmissions, which he observed.

However, all these experiments could not succeed in the generation and detection of free electromagnetic waves. In his speech in commemoration of Herrmann von Helmholtz on December 14, 1894 Wilhelm von Bezold stated that this was “kept in reserve to Hermann von Helmholtz´s greatest and most ingenious scholar Heinrich Hertz”.

References to establish the dates, location, and importance of the achievement: Minimum of five (5), but as many as needed to support the milestone, such as patents, contemporary newspaper articles, journal articles, or citations to pages in scholarly books. At least one of the references must be from a scholarly book or journal article.

[1] Heinrich Hertz, “Gesammelte Werke“, J. A. Barth, Leipzig 1894/95.

[2] Heinrich Hertz, “Electric Waves: Researches on the Propagation of Electric Action with Finite Velocity through Space”, authorized English translation by D. E. Jones. New York, Dover, 1962,-XV. (Dover books on history of science and classics of science).

[3] Heinrich Hertz, “Erinnerungen, Briefe, Tagebücher“, edited by Johanna Hertz. Akademische Verlagsgesellschaft Leipzig, 1927. The English translation is: Heinrich Hertz, "Memoirs - Letters - Diaries", Arranged by Johanna Hertz, Second enlarged edition prepared by Mathilde Hertz and Charles Susskind, English translation by Lisa Brinner, Methilde Hertz and Charles Susskind with a biographical introduction by Max von Laue, San Francsico Press, Inc.

[4] Max Planck, “Gedächtnisrede auf Heinrich Hertz“, Physikalische Abhandlungen und Vortragsreihe, Vol. 3, Braunschweig 1958.

[5] D‘ Agostino, Salvo, “Hertz’s Researches on Electromagnetic Waves. Historical Studies in the Physical Sciences”, Princeton, N.J. – 6(1975), pp. 261-323.

[6] J.G. O’Hara, W. Pricha, “Hertz and the Maxwellians: A Study and Documentation of the Discovery of Electromagnetic Wave Radiation, 1871-1894”, Peregrinus, 1987,-XIV. (IEE history of technology series) ISBN 0-86341-101-0.

[7] B. Santo, IEEE Spectrum, May 1988, p. 58.

[8] Charles Susskind, “Heinrich Hertz: A Short Life”, San Francisco Press, 1995.

[9] “Prof. D. E. Hughes’ Research in Wireless Telegraphy”, The Electrician, Volume 43, 1899, pages 40-41.

[10] "Heinrich Hertz Memoirs - Letters - Diaries Arranged by Johanna Hertz Second enlarged edition prepared by Mathilde Hertz and Charles Susskind English translation by Lisa Brinner, Methilde Hertz and Charles Susskind With a biographical introduction by Max von Laue" San Francsico Press, Inc. 547 Howard Street, San Francisco, California, 94105

Supporting materials (supported formats: GIF, JPEG, PNG, PDF, DOC): All supporting materials must be in English, or if not in English, accompanied by an English translation. You must supply the texts or excerpts themselves, not just the references. For documents that are copyright-encumbered, or which you do not have rights to post, email the documents themselves to ieee-history@ieee.org. Please see the Milestone Program Guidelines for more information.

Fig. 1 Sculpture of Heinrich Hertz in front of the Heinrich Hertz Auditorium on the campus of the Karlsruhe Institute of Technology
Fig. 2 Experimental Setup by Heinrich Hertz (Photo taken by Heinrich Hertz)