Ernst Florens Friedrich Chladni

Ernst Florens Friedrich Chladni (born 30 November 1756) was a German physicist and musician. His most important work, for which he is sometimes labeled the "father of acoustics", included research on vibrating plates and the calculation of the speed of sound for different gases. He also undertook pioneering work in the study of meteorites and so is also regarded by some as the "father of meteoritics".

Chladni discovered Chladni's law, a simple algebraic relation for approximating the modal frequencies of the free oscillations of plates and other bodies. Chladni estimated sound velocities in different gases by placing those gases in an organ pipe and measuring the characteristics of the sounds that emerged when the pipe was played. This built on the work of Pierre Gassendi in measuring the speed of sound in air, which was started in 1635.

In 1794, Chladni published "Über den Ursprung der von Pallas gefundenen und anderer ihr ähnlicher Eisenmassen und über einige damit in Verbindung stehende Naturerscheinungen" ("On the Origin of the Iron Masses Found by Pallas and Others Similar to it, and on Some Associated Natural Phenomena") in which he proposed that meteorites have an extraterrestrial origin. This was a controversial statement at the time, since meteorites were thought to be of volcanic origin. This book made Chladni one of the founders of modern meteorite research.

Source: SheshiBesh Jendelamu 12:03