Ernst Florens Friedrich Chladni

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Ernst Florens Friedrich Chladni

Ernst Florens Friedrich Chladni (born November 30, 1756 in Wittenberg , † April 3, 1827 in Breslau ) was a German physicist and astronomer .

Life

Born as the son of the lawyer Ernst Martin Chladni , he attended the Fürstenschule Grimma from 1771 to 1774 , then studied law at the University of Leipzig and received his doctorate in law in 1782. PhD. After the death of his father, his musical talent encouraged him to deal more with experimental acoustics; In doing so, he was guided by the findings of the mathematicians Leonhard Euler and Daniel Bernoulli . Chladni is known for his work, which established the acoustics . In 1787, for example, he published the first groundbreaking findings that patterns or (knot) lines develop on thin slabs sprinkled with sand when they are set in motion. These are named after him as Chladnian sound figures and also inspired the theory of the elastic plate or plate theory . In a work published in 1796, Chladni described the longitudinal vibrations of the strings and bars, in which the vibrations do not occur transversely to the strings and bars, but in their longitudinal direction.

Chladnian sound figure, illustration 1879

As his knowledge progressed, he realized in 1794 that the theory of sound and sound should not be dealt with in the context of a theory of air, but rather in a theory of the periodic vibrations of elastic bodies. In 1797 further research led to the determination of the speed of sound in solid bodies and gases. At the same time, he proved that the tones produced when igniting hydrogen in a tube can be compared with real whistling tones. In his sound studies he included the vibrations of bells and forks. Chladni's experiments inspired numerous well-known physicists such as Wilhelm Eduard and Ernst Heinrich Weber , Charles Wheatstone , Michael Faraday and Félix Savart to continue their work in the field of acoustics. His findings are used in violin making, high-frequency technology and concert hall architecture to the present day.

He also conducted studies on meteorites. With his book "About the origin of the iron masses found by Pallas and others similar to them and about some related natural phenomena" and other publications, published in 1794 , he put forward the then revolutionary and initially very controversial thesis that the meteorites found on earth were theirs Originate in space and are remnants from the formation phase of the planets in our solar system .

It was in many ways groundbreaking work in the advancement of scientific attitudes since the late 18th century. However, it was initially largely rejected by recognized and famous scholars of his time - including Georg Christoph Lichtenberg , Johann Wolfgang von Goethe and Alexander von Humboldt - especially since measurements by Lichtenberg's students Benzenberg and Brandes had allegedly shown that the meteors were purely atmospheric in origin. Georg Christoph Lichtenberg, however, took into account that Chladni might be right with his hypothesis, and was actually the one who inspired him to work on the origin of meteorites.

But just a few years later, several attested observations and scientifically founded descriptions of meteorite falls (e.g. the meteor shower of L'Aigle in 1803) as well as refined chemical analyzes of the meteorites found (e.g. by Edward Charles Howard ) confirmed his research results. Chladni is considered to be one of the founders of modern meteorite research .

1790 Chladni invented the string mallet Euphon (the base of Cristal baschet ) and 1799 Clavizylinder that the organ stops oboe / bassoon similar in sound. With these instrument inventions he secured his livelihood by performing them on lecture tours throughout Europe, including to Napoleon, Goethe, Lichtenberg and Laplace.

Chladni lived and worked in his hometown Wittenberg until 1813 and in neighboring Kemberg from 1813 .

Chladni was a member of the Leipzig Freemason Lodge Minerva to the three palms . He died during a lecture tour in Breslau and was buried in the Great Cemetery there .

Memorial plaque on the house at Mittelstrasse 5, in Lutherstadt Wittenberg

Honors

In 1793 he was elected a corresponding member of the Göttingen Academy of Sciences . From 1794 he was a corresponding member of the Russian Academy of Sciences in Saint Petersburg . In 1804 he was accepted as a corresponding member of the Bavarian Academy of Sciences and in December 1815 of the Prussian Academy of Sciences .

The lunar crater Chladni and the asteroid (5053) Chladni are named after him.

Fonts (selection)

  • Discoveries about the theory of sound. Weidmanns Erben und Reich, Leipzig 1787, ( digitized and full text in the German text archive , digitized ).
  • Concerning the origin of the iron masses found by Pallas and others similar to it, and some natural phenomena connected with them. Hartknoch, Riga 1794, ( digitized version , digitized version ).
  • The acoustics. Breitkopf & Härtel, Leipzig 1802, ( digitized and full text in the German text archive , digitized ; in French: Traité d'Acoustique. Courcier, Paris 1809, digitized ).
  • New contributions to acoustics. Breitkopf & Härtel, Leipzig 1817, ( digitized version ).
  • About fire meteors, and about the masses that fell with them. Heubner, Vienna 1819, ( digitized version ).
  • Contributions to practical acoustics and the teaching of instrument making, containing the theory and instructions for building the clavicylinder and related instruments. Breitkopf & Härtel, Leipzig 1821, ( digitized version ).
  • About the production of human speech sounds. In: Annals of Physics . NF Vol. 16 = Vol. 76, 1824, pp. 187-216 .
  • Short overview of the theory of sound and sound, together with an appendix concerning the development and arrangement of the tonal relationships. Schott's Sons, Mainz 1827, ( digitized ).

literature

Chladni tradition maintenance in Grimma

The Augustiner-Verein, the support association for the St. Augustin High School in Grimma , awards the Ernst-Florens-Friedrich-Chladni-Prize annually in honor of the former pupil of the Princely School Grimma and in direct connection with his association's goals.

Web links

Commons : Ernst Florens Friedrich Chladni  - Collection of pictures, videos and audio files
Wikisource: Ernst Florens Friedrich Chladni  - Sources and full texts

swell

  1. ^ Karl-Eugen Kurrer : The History of the Theory of Structures. Searching for Equilibrium . Berlin: Ernst & Sohn 2018, p. 703, ISBN 978-3-433-03229-9 .
  2. ^ Franz Krojer: Lichtenberg's “Favorite Thought” and Chladni's Meteor Hypothesis. Difference-Verlag, Munich 2009, ( available online ).
  3. ^ Günter Hoppe: Goethe's views on meteorites and his relationship to the physicist Chladni. In: Goethe yearbook. Vol. 95, 1978, ISSN  0323-4207 , pp. 227-240.
  4. ↑ Ursula B. Marvin: Ernst Florenz Friedrich Chladni (1756-1827) and the origins of modern meteorite research. In: Meteoritics & Planetary Science. Vol. 31, No. 5, 1996, pp. 545-588.
  5. ↑ Holger Krahnke: The members of the Academy of Sciences in Göttingen 1751-2001 (= Treatises of the Academy of Sciences in Göttingen, Philological-Historical Class. Volume 3, Vol. 246 = Treatises of the Academy of Sciences in Göttingen, Mathematical-Physical Class. Episode 3, vol. 50). Vandenhoeck & Ruprecht, Göttingen 2001, ISBN 3-525-82516-1 , p. 58.
  6. ^ Foreign members of the Russian Academy of Sciences. Ernst Florens Friedrich Chladni. Russian Academy of Sciences, accessed November 3, 2015 (Russian).
  7. ↑ Member entry of Ernst Chladni at the Bavarian Academy of Sciences , accessed on January 15, 2017.
  8. ^ Members of the previous academies. Ernst Florens Friedrich Chladni. Berlin-Brandenburg Academy of Sciences , accessed on March 7, 2015 .
personal data
SURNAME Chladni, Ernst Florens Friedrich
BRIEF DESCRIPTION German physicist and astronomer
DATE OF BIRTH November 30, 1756
PLACE OF BIRTH Wittenberg
DATE OF DEATH April 3, 1827
Place of death Wroclaw