Chladni, Ernst Florens Friedrich

Chladni, Ernst Florens Friedrich

(ĕrnst flō`rĕns frē`drĭkh kläd`nē), 1756–1827, German physicist. An authority on acoustics, he made studies of the transmission of sound in various gases and of vibrating plates of glass and metal covered with sand, on which were formed the so-called Chladni figures, or acoustic figures. He invented a musical instrument that he called the euphonium. Chladni also studied meteorites and proposed that they are of extraterrestrial origin.
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The following article is from The Great Soviet Encyclopedia (1979). It might be outdated or ideologically biased.

Chladni, Ernst Florens Friedrich

 

Born Nov. 30, 1756, in Wittenberg; died Apr. 3, 1827, in Breslau, now Wrocław, Poland. German scientist in experimental acoustics and meteoritics.

In accordance with the wishes of his father, a prominent jurist, Chladni studied law in Wittenberg and in Leipzig. He was the first to undertake experimental studies of various acoustic phenomena, many of which were theoretically explained much later. He discovered longitudinal vibrations in strings and rods and studied the vibrational modes of rods, tuning forks, bells, and plates. He observed torsional vibrations in rods.

Chladni was the first to determine with reasonable accuracy the speed of sound in various gases. He also measured the ratios of the speeds of sound in various materials to the speed of sound in air. He explained echoes and established the upper threshold of audibility. In 1787 he described the figures that are formed in sand sprinkled on the surface of a vibrating elastic plate; such figures are called Chladni figures.

In 1794, Chladni explained correctly for the first time the origin of pallasites. He also developed the theory that meteorites originate in space and burn up when they enter the earth’s atmosphere.

Chladni invented peculiar musical instruments which he called the clavicylinder and the euphonium. He became a corresponding member of the St. Petersburg Academy of Sciences and Arts in 1794.

REFERENCES

Melde, F. E. Chladni’s Leben und Wirken, nebst einem chronologischen Verzeichnis seiner literärischen Arbeiten, 2nd ed. Marburg, 1888.
“E. F. F. Chladni (1756–1827).” Nature, 1956, vol. 178, no. 4543.
The Great Soviet Encyclopedia, 3rd Edition (1970-1979). © 2010 The Gale Group, Inc. All rights reserved.