Ernst Chladni

Ernest Florenz Friedrich Chladni (November 30, 1756–April 3, 1827) was a German physicist. File history Legend: (cur) = this is the current file, (del) = delete this old version, (rev) = revert to this old version. ... November 30 is the 334th day (335th on leap years) of the year in the Gregorian Calendar, with 31 days remaining. ... 1756 was a leap year starting on Thursday (see link for calendar). ... April 3 is the 93rd day of the year (94th in leap years) in the Gregorian calendar, with 272 days remaining. ... Naval Battle of Navarino by Carneray 1827 was a common year starting on Monday (see link for calendar). ... The first few hydrogen atom electron orbitals shown as cross-sections with color-coded probability density. ...

Chladni was born in Wittenberg. His important works include research on vibrating plates and the calculation of the speed of sound for different gases. Statue of Martin Luther in the main square Wittenberg, officially [Die] Lutherstadt Wittenberg, is a town in Germany, in the Bundesland Saxony-Anhalt, at 12° 59 E, 51° 51 N, on the Elbe river. ... Oscillation is the variation, typically in time, of some measure as seen, for example, in a swinging pendulum. ... The speed of sound is a term used to describe the speed of sound waves passing through an elastic medium. ...

Chladni Plates

Chladni modes of a guitar plate

One of Chladni's most well known achievements was inventing a technique to show the various modes of vibration in a mechanical surface. Image File history File links Chladni_guitar. ... Image File history File links Chladni_guitar. ... Various normal modes in a 1D-lattice. ...

Chladni's technique, first published in 1787 his book, Entdeckungen ueber die Theorie des Klanges, consists of drawing a bow over a piece of metal whose surface is lightly covered with sand. The plate is bowed until it reaches resonance and the sand forms a pattern showing the nodal regions . Since the 20th century it has become more common to place a loudspeaker driven by an electronic signal generator over or under the plate to achieve a more accurate adjustible frequency. A cello bow In music, a bow is a device pulled across the strings of a string instrument in order to make them vibrate and emit sound. ... A signal generator, also known variously as a test signal generator, tone generator (in audio only), waveform generator, or frequency generator is an electronic instrument that generates repeating electronic signals (in either the analog or digital domains). ...

Variations of this technique are commonly used in the design and construction of acoustic instruments such as violins, guitars, and cellos. This does not cite its references or sources. ... This article or section does not cite its references or sources. ... The violoncello, almost always abbreviated to cello, or cello (the c is pronounced as the ch in cheese), is a stringed instrument and a member of the violin family. ...

Other Works

He invented a musical instrument called Chladni's euphonium, consisting of glass rods of different pitches, which should not be confused with a brass euphonium. He also discovered Chladni's law. The euphonium is a conical-bore, tenor-voiced brass instrument. ... Chladnis law, named after Ernst Chladni, relates the frequency of modes of vibration for flat circular surfaces with fixed center relative to the numbers m of diametric (linear) nodes and n of radial (circular) nodes. ...

In 1794, Chladni published, in German, 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 Pallas Iron and Others Similar to it, and on Some Associated Natural Phenomena), in which he proposed that meteorites have their origins in outer space. This was a very controversial statement at the time, and with this book Chladni also became one of the founders of modern meteorite research. Peter Simon Pallas (September 22, 1741 - September 8, 1811) was a German-born Russian zoologist. ... Willamette Meteorite A meteorite is an extraterrestrial body that survives its impact with the Earths surface without being destroyed. ...

See Also

Based on Chladni's work, photographer Alexander Lauterwasser captures imagery of water surfaces set into motion by sound sources ranging from pure sine waves to music by Ludwig van Beethoven, Karlheinz Stockhausen and even overtone singing. This article or section does not cite its references or sources. ... In trigonometry, an ideal sine wave is a waveform whose graph is identical to the generalized sine function y = Asin[ω(x − α)] + C, where A is the amplitude, ω is the angular frequency (2π/P where P is the wavelength), α is the phase shift, and C... Beethoven redirects here. ... Karlheinz Stockhausen (born August 22, 1928) is a German composer, one of the most important and controversial composers of the 20th century. ... Physical representation of overtones Overtone singing, also known as overtone chanting, harmonic singing, or harmonic chant, is a type of singing in which the singer manipulates the harmonic resonances (or formants) created as air travels from the lungs, past the vocal folds, and out the lips. ...

Further reading

• Rossing T.D. (1982) Chladni's Law for Vibrating Plates, American Journal of Physics 50, 271-274
• Marvin U.B. (1996) Ernst Florenz Friedrich Chladni (1756-1827) and the origins of modern meteorite research, Meteoritics & Planetary Science 31, 545-588

External links

• Examples with round, square, stadium plates and violin shapes
• Chladni plates
• Chladni Plate Mathematics by Paul Bourke
• 3-dimensional Chladni surfaces by Paul Bourke
• Electromagnetically driven Chladni plate
• Use of Chladni patterns in the construction of violins
• Chladni patterns for guitar plates
• Modal Analysis of Percussion Instruments Using Vibrational Holography -- Vibrational holograpy uses coherent light instead of sand.