Georg Ohm
Georg Simon Ohm | |
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University of Munich | |
Doctoral advisor | Karl Christian von Langsdorf |
Georg Simon Ohm (
Biography
Early life
Georg Simon Ohm was born into a
From early childhood, Georg and Martin were taught by their father who brought them to a high standard in
Life in university
Georg Ohm's father, concerned that his son was wasting his educational opportunity, sent Ohm to Switzerland. There in September 1806 Ohm accepted a position as a mathematics teacher in a school in Gottstadt bei Nidau.
Teaching career
Ohm's own studies prepared him for his doctorate which he received from the University of Erlangen on October 25, 1811. He immediately joined the faculty there as a lecturer in mathematics but left after three semesters because of unpromising prospects. He could not survive on his salary as a lecturer. The Bavarian government offered him a post as a teacher of mathematics and physics at a poor quality school in Bamberg which Ohm accepted in January 1813. Unhappy with his job, Georg began writing an elementary textbook on geometry as a way to prove his abilities. That school was closed in February 1816. The Bavarian government then sent Ohm to an overcrowded school in Bamberg to help out with the teaching of mathematics.
After his assignment in Bamberg, Ohm sent his completed manuscript to King Wilhelm III of Prussia. The King was satisfied with Ohm's book, and offered Ohm a position at the Jesuit Gymnasium of Cologne on 11 September 1817. This school had a reputation for good science education and Ohm was required to teach physics in addition to mathematics. The physics laboratory was well equipped, allowing Ohm to begin experiments in physics. As the son of a locksmith, Ohm had some practical experience with mechanical devices.
Ohm published Die galvanische Kette, mathematisch bearbeitet (The Galvanic Circuit Investigated Mathematically) in 1827. Ohm's college did not appreciate his work and Ohm resigned from his position. He then made an application to, and was employed by, the
In 1849, Ohm published Beiträge zur Molecular-Physik (Molecular Physics). In the preface of this work he stated he hoped to write a second and third volume "and if God gives me length of days for it, a fourth". However, on finding that an original discovery recorded in it was being anticipated by a Swedish scientist he did not publish it, stating: "The episode has given a fresh and deep sense for my mind to the saying 'Man proposes, and God disposes'. The project that gave the first impetus to my inquiry has been dissipated into mist, and a new one, undesigned by me, has been accomplished in its place."[7]
Ohm died in Munich in 1854,[6] and is buried in the Alter Südfriedhof. A collection of his family letters would be compiled in a German book, which shows that he used to sign some of his letters with the expression "Gott befohlen, G S Ohm,"[8] meaning "Commended to God".[9]
Discovery of Ohm's law
Ohm's law first appeared
The book begins with the mathematical background necessary for an understanding of the rest of the work. While his work greatly influenced the theory and applications of current electricity,[5] it was coldly received at that time. Ohm presents his theory as one of contiguous action, a theory which opposed the concept of action at a distance. Ohm believed that the communication of electricity occurred between "contiguous particles" which is the term he himself used. The paper is concerned with this idea, and in particular with illustrating the differences in this scientific approach of Ohm's and the approaches of Joseph Fourier and Claude-Louis Navier.[12]
A study of the
Ohm's acoustic law
Ohm's acoustic law, sometimes called the acoustic phase law or simply Ohm's law, states that a musical sound is perceived by the ear as a set of a number of constituent pure harmonic tones. It is well known to be not quite true.[15]
Study and publications
His first paper in 1825 examined the decrease in the electromagnetic force produced by a wire as the length of the wire increased. In 1826, he gave a description of conduction in circuits modelled on Fourier's study of heat conduction. This paper continued Ohm's deduction of results from experimental evidence and, particularly in the second, he was able to propose laws which went a long way to explaining results of others working on galvanic electricity.
Although Ohm's work strongly influenced theory, at first it was received with little enthusiasm. However, his work was eventually recognized by the Royal Society with its award of the Copley Medal in 1841.[17] He became a foreign member of the Royal Society in 1842, and in 1845 he became a full member of the Bavarian Academy of Sciences and Humanities. At some extent, Charles Wheatstone drew attention to the definitions which Ohm had introduced in the field of physics.[18]
Works
- Grundlinien zu einer zweckmäßigen Behandlung der Geometrie als höheren Bildungsmittels an vorbereitenden Lehranstalten [Guidelines for an appropriate treatment of geometry in higher education at preparatory institutes] (in German). Palm und Enke. 1817 – via Google Books.
- Die galvanische Kette : mathematisch bearbeitet (in German). Berlin: T.H. Riemann. 1827 – via Google Books.
- English translation: The Galvanic circuit investigated mathematically. Translated by Francis, William. New York: D. Van Nostrand Company. 1891 – via Google Books.
- Beiträge zur Molecular-Physik. Erster Band. Elemente der analytischen Geometrie im Raume am schiefwinkligen Coordinatensysteme [Contributions to molecular physics. First volume. Elements of analytic geometry concerning the skew coordinate system] (in German). Nürnberg: Schrag. 1849 – via Internet Archive.
- Erklärung aller in einaxigen Krystallplatten zwischen geradlinig polarisirstem Lichte wahrnehmbaren Interferenz-Erscheinungen in mathematischer Form mitgetheilt (in German). München: k. bayr. Akademie der Wissenschaften.
- Erste Hälfte [First half], 1852 — via Munich Digitization Center
- Zweite Hälfte [Second half], 1853 — via Google Books
- Grundzüge der Physik als Compendium zu seinen Vorlesungen [Fundamentals of physics: Compendium of lectures]. Nürnberg: Schrag.
- Erste Abtheilung, Allgemeine Physik [Volume 1 General Physics], 1854 — via Google Books
- Zweite Abtheilung, Besondere Physik [Volume 2 Special Physics], 1854 — via Google Books
See also
- Ohm (unit)
Notes
- ^ Ohm's law, that electric current is proportional to a potential difference, was first discovered by Henry Cavendish, but Cavendish did not publish his electrical discoveries in his lifetime and they did not become known until 1879, long after Ohm had independently made the discovery and published himself. Thus the law came to bear the name of Ohm.
References
- ^ "Ohm". Random House Webster's Unabridged Dictionary.
- ISBN 978-3-411-04067-4.
- ISBN 978-3-11-018202-6.
- ^ Keithley, Joseph F. (1999). The Story of Electrical and Magnetic Measurements: From 500 BC to the 1940s. John Wiley & Sons
- ^ a b c public domain: Chisholm, Hugh, ed. (1911). "Ohm, Georg Simon". Encyclopædia Britannica. Vol. 20 (11th ed.). Cambridge University Press. p. 34. One or more of the preceding sentences incorporates text from a publication now in the
- ^ a b c Chisholm 1911, p. 34.
- ^ Kneller, Karl Alois; Kettle, Thomas Michael (1911). Christianity and the leaders of modern science; a contribution to the history of culture in the nineteenth century. Freiburg im Breisgau, pp. 17–18
- ^ Georg Simon Ohm (2002), Georg Simon Ohm: nachgelassene Schriften und Dokumente aus seinem Leben : mit Schriftstücken seiner Vorfahren und Briefen seines Bruders Martin. Palm und Enke. p. 216; 219
- OCLC 386451.
- ^ Die galvanische kette: mathematisch By Georg Simon Ohm Pg. 181
- ^ The galvanic circuit investigated mathematically By Georg Simon Ohm Pg. 202
- ^ Pourprix, B. (1995). "G. S. Ohm théoricien de l'action contiguë". Archives internationales d'histoire des sciences (in French). 45 (134): 30–56.
- .
- .
- ^
Robert Sekuler (1974). "Spatial Vision". In Mark R. Rosenzweig (ed.). Annual Review of Psychology, Vol. 25. Annual Reviews Inc. p. 215. ISBN 978-0-8243-0225-2.
- ^ Tatum, Jeremy (11 August 2020). "Resistance and Ohm's Law". Physics – Libre texts. Retrieved 13 April 2021.
- ISBN 978-1-4899-6038-2.
- ^ Merz, John Theodore (1903). "A history of European thought in the nineteenth century", pp. 365–366
External links
- Works by or about Georg Simon Ohm at Wikisource
- Quotations related to Georg Ohm at Wikiquote
- O'Connor, John J.; Robertson, Edmund F., "Georg Ohm", MacTutor History of Mathematics Archive, University of St Andrews
- The American Cyclopædia. 1879. .