Chladni, Ernst (Florenz Friedrich)
- C. Truesdell
- and Clive Greated
(b Wittenberg, Nov 30, 1756; d Breslau [now Wrocław], April 3, 1827). German acoustician. He studied law at Leipzig University before turning to scientific studies. He invented two instruments, the ‘euphon’ and the ‘klavizylinder’, both of which were variants of the glass harmonica. However, he owes his fame to his celebrated experiments on the nodal patterns and corresponding frequencies of vibration plates. He showed that the vibration patterns, often called Chladni figures, could be made visible by sprinkling sand on the plate. The sand is thrown up on vibrating areas and collects around nodal lines. Chladni travelled through Europe playing on his instruments and demonstrating his experiments before many persons and institutions; he encountered Goethe, Lichtenberg, Olbers, Laplace, Napoleon and other notable men of the period. Chladni's experiments stimulated much early work on the vibration of plates and bars and indeed so impressed the Académie des Sciences, Paris, that it offered a prize for a successful explanation of his sand figures and the motion of elastic surfaces in general. His work helped to form the foundation of modern theories, capable of predicting precise vibration patterns for violin and guitar top plates and the soundboards of keyboard instruments....