Ernst Chladni
Ernst Florens Friedrich Chladni ( born November 30, 1756 in Wittenberg, † April 3, 1827 in Breslau) was a German physicist and astronomer.
Life
As the son of the jurist Ernst Martin Chladni was born, he attended from 1771 to 1774, the Prince's School Grimsby, then studied at the University of Leipzig law and in 1782 a doctorate in law. doctorate. After the death of his father encouraged him his musical talent to deal more with the experimental acoustics; while he was based on the findings of Leonhard Euler and Daniel Bernoulli. Chladni is known for his work, which justified the acoustics. He published in 1787 the first groundbreaking insights about the fact that on sanded thin plates or pattern (node ) lines are formed when these vibrated. These are referred to by him as Chladni figures. In 1796 published work Chladni described the longitudinal vibrations of the strings and rods, in which the vibrations do not take place transversely to the strings, bars, but in the longitudinal direction.
With advancing knowledge, he realized in 1794 that the sound and sound doctrine should not be treated as part of a study of air, but is to be settled a doctrine of the periodic oscillations of elastic bodies. 1797 resulted in further research to determine the speed of sound in solids and gases. At the same time, he proved that one can compare the spawned on ignition of hydrogen in a tube tones with real whistling. In his studies he moved into doing a sound vibrations of bells and forks. Chladni's experiments suggested numerous well-known physicists such as Wilhelm Eduard and Ernst Heinrich Weber, Charles Wheatstone, Michael Faraday and Felix Savart, continue work in the field of acoustics. Up to the present his findings are crafting a violin, used in the high-frequency technology and the concert hall architecture.
In addition, he conducted studies on meteorites. With his 1794 published book " On the Origin of the found and the other of Pallas their similar masses of iron and some so related natural phenomena " and other publications, he turned to the then revolutionary and initially very controversial thesis that the meteorites found on Earth their have origin in space and remnants of the formation phase of the planets of our solar system were.
It was a breakthrough in many ways working for the advancement of scientific views since the late 18th century. However, it was initially by recognized and famous scholars of his time - largely rejected, since measurements of the Lichtenberg- student Benzenberg and Brandes had allegedly revealed that the meteors purely atmospheric origin were - including Georg Christoph Lichtenberg, Johann Wolfgang von Goethe and Alexander von Humboldt. Georg Christoph Lichtenberg, however, drew quite into account that Chladni could have with his hypothesis right, and was actually the one who encouraged him to his work on the origin of meteorites.
But a few years later was confirmed by several testified observations and scientifically sound descriptions of meteorite falls (eg, the meteor shower of L' Aigle in 1803 ) and refined chemical analysis of the meteorite found ( inter alia, by Edward Charles Howard) his research. Chladni is now considered one of the founders of modern meteorite research.
1790 Chladni invented the coating rod Games Euphon (the base of Cristal Baschet ) and 1799 the Clavizylinder that are similar in sound to the organ stops oboe / bassoon. With this instrument inventions he secured his livelihood by making them vorführte on lecture tours throughout Europe, so even before Napoleon, Goethe, Lichtenberg and Laplace.
Chladni lived and worked until 1813 in his hometown of Wittenberg, from 1813 in the neighboring Kemberg. He died during a lecture tour in Breslau and was buried in the local cemetery Great.
Chladni was a member of the Leipzig Masonic Lodge Minerva of the three palm trees.
The lunar crater Chladni is named after him.
Writings
- Discoveries on the theory of sound. Leipzig 1787
- The acoustics. Leipzig 1802, French translation: Traite d' acoustique, Paris 1809 and in: New contributions to acoustics, Leipzig 1817
- Contributions to practical acoustic and doctrine of the Instrument making. Leipzig 1821
- On the Origin of Pallas found by her and other similar masses of iron. Leipzig, Riga 1794
- About fire meteors. Vienna 1820
- About the production of human speech sounds. Leipzig 1824
- Brief overview of the sound and sound doctrine, together with an appendix the development and arrangement of the tonal concerning. Mainz 1827