m Open access bot: url-access=subscription updated in citation with #oabot.
Line 6:
Line 6:
| image_size = 150px
| image_size = 150px
| birth_date = {{birth-date|30 November 1756}}
| birth_date = {{birth-date|30 November 1756}}
| birth_place = [[Wittenberg]], [[Electorate of Saxony|Saxony]]
| birth_place = [[Wittenberg]], [[Electorate of Saxony]]
| death_date = {{death-date and age|3 April 1827|30 November 1756}}
| death_date = {{death-date and age|3 April 1827|30 November 1756}}
| death_place = [[Breslau]], [[Kingdom of Prussia|Prussia]], [[German Confederation]]
| death_place = [[Breslau]], [[Kingdom of Prussia|Prussia]], [[German Confederation]]
Line 33:
Line 33:
Chladni came from an educated family of academics and learned men. Chladni's great-grandfather, the [[Lutheran]] clergyman Georg Chladni (1637–1692), had left Kremnica in 1673 during the [[Counter Reformation]]. Chladni's grandfather, Martin Chladni (1669–1725), was also a Lutheran theologian and, in 1710, became professor of [[theology]] at the [[Martin Luther University of Halle-Wittenberg|University of Wittenberg]]. He was dean of the theology faculty in 1720–1721 and later became the university's [[Rector (academia)|rector]]. Chladni's uncle, Justus Georg Chladni (1701–1765), was a law professor at the university.{{Citation needed |date=July 2008}}
Chladni came from an educated family of academics and learned men. Chladni's great-grandfather, the [[Lutheran]] clergyman Georg Chladni (1637–1692), had left Kremnica in 1673 during the [[Counter Reformation]]. Chladni's grandfather, Martin Chladni (1669–1725), was also a Lutheran theologian and, in 1710, became professor of [[theology]] at the [[Martin Luther University of Halle-Wittenberg|University of Wittenberg]]. He was dean of the theology faculty in 1720–1721 and later became the university's [[Rector (academia)|rector]]. Chladni's uncle, Justus Georg Chladni (1701–1765), was a law professor at the university.{{Citation needed |date=July 2008}}
Another uncle, Johann Martin Chladni (1710–1759), was a theologian, a historian and a professor at the [[Friedrich-Alexander-University, Erlangen-Nuremberg|University of Erlangen]] and the [[University of Leipzig]].
Another uncle, Johann Martin Chladni (1710–1759), was a theologian, a historian and a professor at the [[University of Erlangen]] and the [[University of Leipzig]].
Chladni's father, Ernst Martin Chladni (1715–1782), was a law professor and rector of the University of Wittenberg. He had joined the law faculty there in 1746.{{Citation needed |date=July 2008}} Chladni's mother was Johanna Sophia and he was an [[only child]].<ref name="Hockey"/> His father disapproved of his son's interest in science and insisted that Chladni would become a lawyer.<ref name="springer" /><ref name="columbia" /><ref name="oxford" />
Chladni's father, Ernst Martin Chladni (1715–1782), was a law professor and rector of the University of Wittenberg. He had joined the law faculty there in 1746.{{Citation needed |date=July 2008}} Chladni's mother was Johanna Sophia and he was an [[only child]].<ref name="Hockey"/> His father disapproved of his son's interest in science and insisted that Chladni would become a lawyer.<ref name="springer" /><ref name="columbia" /><ref name="oxford" />
Line 46:
Line 46:
[[File:Chladni pattern 2.jpg|thumb|Another mode of the same plate]]
[[File:Chladni pattern 2.jpg|thumb|Another mode of the same plate]]
One of Chladni's best-known achievements was inventing a technique to show the various [[Normal mode|modes of vibration]] on a rigid surface, known as '''Chladni figures''' or '''Chladni patterns''' due to the various shapes or patterns created by various modes. When [[Resonance|resonating]], a plate or membrane is divided into regions that vibrate in opposite directions, bounded by lines where no vibration occurs ([[Node (physics)|nodal lines]]). Chladni repeated the pioneering experiments of [[Robert Hooke]] who, on 8 July, 1680, had observed the [[Cymatics|nodal patterns]] associated with the vibrations of glass plates. Hooke ran a violin [[Bow (music)|bow]] along the edge of a plate covered with flour and saw the nodal patterns emerge.<ref name="Hooke-Diary"/><ref name="columbia" /><ref name="oxford" /><ref name="Galileo"/>
One of Chladni's best-known achievements was inventing a technique to show the various [[Normal mode|modes of vibration]] on a rigid surface, known as '''Chladni figures''' or '''Chladni patterns''' due to the various shapes or patterns created by various modes. When [[Resonance|resonating]], a plate or membrane is divided into regions that vibrate in opposite directions, bounded by lines where no vibration occurs ([[Node (physics)|nodal lines]]). Chladni repeated the pioneering experiments of [[Robert Hooke]] who, on 8 July, 1680, had observed the [[Cymatics|nodal patterns]] associated with the vibrations of glass plates. Hooke ran a violin [[Bow (music)|bow]] along the edge of a plate covered with flour and saw the nodal patterns emerge.<ref name="Hooke-Diary"/><ref name="columbia" /><ref name="oxford" /><ref name="Galileo"/> Hooke had already observed this 9 years earlier in 1671, and in turn was inspired by a suggestion he read in [[Francis Bacon|Bacon]]'s ''Sylva Sylvarum'', where Bacon describes rubbing the rim of a glass filled with water and observing the water "frisk and sprinkle". Hooke presented this in 1680 to the [[Royal Society]], and there was no follow-up.<ref>{{Cite journal |last=Gouk |first=Penelope M. |date=1982 |title=Acoustics in the Early Royal Society 1660-1680 |url=https://www.jstor.org/stable/531772 |journal=Notes and Records of the Royal Society of London |volume=36 |issue=2 |pages=155–175 |doi=10.1098/rsnr.1982.0009 |jstor=531772 |issn=0035-9149|url-access=subscription }}</ref>
Chladni's technique, first published in 1787 in his book ''Entdeckungen über die Theorie des Klanges'' ("Discoveries in the Theory of Sound"), consisted of drawing a bow over a piece of metal whose surface was lightly covered with sand. The plate was bowed until it reached resonance, when the vibration causes the sand to move and concentrate along the nodal lines where the surface is still, outlining the nodal lines. The patterns formed by these lines are what are now called ''Chladni figures''. Similar nodal patterns can also be found by assembling microscale materials on [[Faraday waves]].<ref name="Chen"/>
Chladni's technique, first published in 1787 in his book ''Entdeckungen über die Theorie des Klanges'' ("Discoveries in the Theory of Sound"), consisted of drawing a bow over a piece of metal whose surface was lightly covered with sand. The plate was bowed until it reached resonance, when the vibration causes the sand to move and concentrate along the nodal lines where the surface is still, outlining the nodal lines. The patterns formed by these lines are what are now called ''Chladni figures''. Similar nodal patterns can also be found by assembling microscale materials on [[Faraday waves]].<ref name="Chen"/>
Line 60:
Line 60:
[[File:Clavicilindro.png|thumb|Clavicylinder]]
[[File:Clavicilindro.png|thumb|Clavicylinder]]
Since at least 1738, a musical instrument called a ''Glasspiel'' or ''verrillon'', created by filling beer glasses with varying amounts of water, was popular in Europe.<ref name="Schlesinger"/> The beer glasses were struck by wooden mallets shaped like spoons to produce "church and other solemn music".<ref name="e1911" /> [[Benjamin Franklin]] was sufficiently impressed by a verrillon performance on a visit to London in 1757 that he created his own instrument, the [[glass armonica]], in 1762.
Since at least 1738, a musical instrument called a ''Glasspiel'' or ''verrillon'', created by filling beer glasses with varying amounts of water, was popular in Europe.<ref name="Schlesinger"/> The beer glasses were struck by wooden mallets shaped like spoons to produce "church and other solemn music".<ref name="e1911" /> [[Benjamin Franklin]] was sufficiently impressed by a verrillon performance on a visit to London in 1757 that he created his own instrument, the [[glass harmonica]], in 1762.
Franklin's armonica inspired several other instruments, including two created by Chladni. In 1791, Chladni invented the musical instrument called the ''euphon'' (not to be confused with the brass instrument [[euphonium]]), consisting of glass rods used to play different pitches. Chladni's euphon is the direct ancestor of the modern day musical instrument known as the ''[[Cristal Baschet]]''.<ref name="Khazam"/> Chladni also improved on Hooke's "musical cylinder" to produce another instrument, the clavicylinder, in 1799.<ref name="columbia" /><ref name="oxford" /><ref name="e1911"/>
Franklin's harmonica inspired several other instruments, including two created by Chladni. In 1791, Chladni invented the musical instrument called the ''euphon'' (not to be confused with the brass instrument [[euphonium]]), consisting of glass rods used to play different pitches. Chladni's euphon is the direct ancestor of the modern day musical instrument known as the ''[[Cristal Baschet]]''.<ref name="Khazam"/> Chladni also improved on Hooke's "musical cylinder" to produce another instrument, the clavicylinder, in 1799.<ref name="columbia" /><ref name="oxford" /><ref name="e1911"/>
Chladni travelled throughout Europe with his instruments giving demonstrations.<ref name="springer"/>
Chladni travelled throughout Europe with his instruments giving demonstrations.<ref name="springer"/>
Line 91:
Line 91:
== Works ==
== Works ==
* [[File:Chladni-2.jpg|thumb|First page of a 1787 copy of ''"Entdeckungen über die Theorie"'']][http://echo.mpiwg-berlin.mpg.de/ECHOdocuView?url=/permanent/library/5M6VYMSC/pageimg&mode=imagepath&pn=5 ''Entdeckungen über die Theorie des Klanges''], Leipzig 1787.
* [[File:Chladni-2.jpg|thumb|First page of a 1787 copy of ''"Entdeckungen über die Theorie des Klanges"'']][http://echo.mpiwg-berlin.mpg.de/ECHOdocuView?url=/permanent/library/5M6VYMSC/pageimg&mode=imagepath&pn=5 ''Entdeckungen über die Theorie des Klanges''], Leipzig 1787.
* [https://archive.org/details/b22017604 ''Die Akustik''], Leipzig 1802. French translation: ''Traite d'acoustique'', Paris 1809. Also in ''Neue Beiträge zur Akustik'', Leipzig 1817.
* [https://archive.org/details/b22017604 ''Die Akustik''], Leipzig 1802. French translation: ''Traité d'acoustique'', Paris 1809. Also in ''Neue Beiträge zur Akustik'', Leipzig 1817.
* ''Beiträge zur praktischen Akustik und zur Lehre vom Instrumentbau'', Leipzig 1821 ({{OCLC|457664981}}).
* ''Beiträge zur praktischen Akustik und zur Lehre vom Instrumentbau'', Leipzig 1821 ({{OCLC|457664981}}).
* {{HathiTrust Catalog|id=007266663|title=Über den Ursprung der von Pallas gefundenen und anderer ihr ähnlicher Eisenmassen}}, Leipzig/Riga 1794.
* {{HathiTrust Catalog|id=007266663|title=Über den Ursprung der von Pallas gefundenen und anderer ihr ähnlicher Eisenmassen}}, Leipzig/Riga 1794.
Line 180:
Line 180:
<ref name="Britannica">[http://www.britannica.com/eb/topic-113430/Ernst-Florens-Friedrich-Chladni "Ernst Florens Friedrich Chladni, or Ernst F. F. Chladni (German physicist)"], ''[[Encyclopædia Britannica]]'': Related Articles</ref>
<ref name="Britannica">[http://www.britannica.com/eb/topic-113430/Ernst-Florens-Friedrich-Chladni "Ernst Florens Friedrich Chladni, or Ernst F. F. Chladni (German physicist)"], ''[[Encyclopædia Britannica]]'': Related Articles</ref>
<ref name="scienceandsociety">[http://www.scienceandsociety.co.uk/results.asp?image=10300907&wwwflag=2&imagepos=6 Ernst Florens Friedrich Chladni, German physicist, 1802 Image Preview], [http://www.scienceandsociety.co.uk/index.asp?clientinfo=0&image=&txtkeys1=&btnshow.x=&btnshow=&lstpasteboards= Science and Society Picture Library]</ref>
<ref name="scienceandsociety">[http://www.scienceandsociety.co.uk/results.asp?image=10300907&wwwflag=2&imagepos=6 Ernst Florens Friedrich Chladni, German physicist, 1802 Image Preview], [http://www.scienceandsociety.co.uk/index.asp?clientinfo=0&image=&txtkeys1=&btnshow.x=&btnshow=&lstpasteboards= Science and Society Picture Library]</ref>
<ref name="springer">[https://doi.org/10.1140%2Fepjst%2Fe2007-00145-4 "Life and work of E.F.F. Chladni"], D. Ullmann1, ''The European Physical Journal'' – Special Topics, Springer, Berlin / Heidelberg, {{ISSN|1951-6355}} (Print) {{ISSN|1951-6401}} (Online), Issue Volume 145, Number 1, June 2007, {{doi|10.1140/epjst/e2007-00145-4}}, pp. 25–32</ref>
<ref name="springer">[https://doi.org/10.1140%2Fepjst%2Fe2007-00145-4 "Life and work of E.F.F. Chladni"], D. Ullmann1, ''The European Physical Journal'' – Special Topics, Springer, Berlin / Heidelberg, {{ISSN|1951-6355}} (Print) {{ISSN|1951-6401}} (Online), Issue Volume 145, Number 1, June 2007, {{doi|10.1140/epjst/e2007-00145-4}}, pp. 25–32</ref>
<ref name="Hockey">{{cite book |title=The Biographical Encyclopedia of Astronomers |last=Hockey |first=Thomas |year=2009 |publisher=[[Springer Publishing]] |isbn=978-0-387-31022-0 |access-date=22 August 2012 |url=http://www.springerreference.com/docs/html/chapterdbid/58280.html}}</ref>
<ref name="Hockey">{{cite book |title=The Biographical Encyclopedia of Astronomers |last=Hockey |first=Thomas |year=2009 |publisher=[[Springer Publishing]] |isbn=978-0-387-31022-0 |access-date=22 August 2012 |url=http://www.springerreference.com/docs/html/chapterdbid/58280.html}}</ref>
Line 196:
Line 196:
<ref name="Pallas">Chladni, Ernst Florens Friedrich, ''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 [[Peter Simon Pallas|Pallas]] and others similar to it, and on some natural phenomena associated with them] (Riga, Latvia: [[Johann Friedrich Hartknoch]], 1794). Available on-line at: [http://digital.slub-dresden.de/werkansicht/dlf/79533/5/ Saxon State and University Library at Dresden, Germany].</ref>
<ref name="Pallas">Chladni, Ernst Florens Friedrich, ''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 [[Peter Simon Pallas|Pallas]] and others similar to it, and on some natural phenomena associated with them] (Riga, Latvia: [[Johann Friedrich Hartknoch]], 1794). Available on-line at: [http://digital.slub-dresden.de/werkansicht/dlf/79533/5/ Saxon State and University Library at Dresden, Germany].</ref>
<ref name="McSween">{{cite book |last=McSween |first=Harry Y. |title=Meteorites and Their Parent Planets |year=1999 |publisher=Cambridge University Press |location=Cambridge [u.a.] |isbn=978-0-521-58303-9 |edition=2nd}}</ref>
<ref name="McSween">{{cite book |last=McSween |first=Harry Y. |title=Meteorites and Their Parent Planets |year=1999 |publisher=Cambridge University Press |location=Cambridge [u.a.] |isbn=978-0-521-58303-9 |edition=2nd}}</ref>
<ref name="Williams">{{cite book |last=Williams |first=Henry Smith |title=A History of Science |chapter-url=https://books.google.com/books?id=hNEFAAAAIAAJ&pg=PA168 |volume=3 |year=1904 |publisher=Harper |page=168ff |chapter=5 |isbn=978-0-250-40142-0 |url=https://archive.org/details/1976solarupdatef0000will/page/168 |url-access=registration }}</ref>
<ref name="Williams">{{cite book |last=Williams |first=Henry Smith |title=A History of Science |chapter-url=https://books.google.com/books?id=hNEFAAAAIAAJ&pg=PA168 |volume=3 |year=1904 |publisher=Harper |page=168ff |chapter=5 |url=https://archive.org/details/1976solarupdatef0000will/page/168 |url-access=registration }} {{isbn|978-0-250-40142-0 }}</ref>
<ref name="Cowen">Ron Cowen. “After the Fall.” ''Science News'', vol. 148, no. 16, 1995, pp. 248–249. ''JSTOR'', www.jstor.org/stable/4018119. Accessed 16 March 2020.</ref>
<ref name="Cowen">Ron Cowen. “After the Fall.” ''Science News'', vol. 148, no. 16, 1995, pp. 248–249. ''JSTOR'', www.jstor.org/stable/4018119. Accessed 16 March 2020.</ref>
<ref name="Howard">{{cite journal |last1=Howard |first1=Edward |date=1802 |title=Experiments and Observations on certain stony and metalline Substances, which at different Times are said to have fallen on the Earth; also on various Kinds of native Iron |url=https://books.google.com/books?id=oAVGAAAAMAAJ&pg=PA168 |journal=Philosophical Transactions of the Royal Society of London |volume=92 |pages=168–212 |bibcode=1802RSPT...92..168H |doi=10.1098/rstl.1802.0009 |doi-access=free}}</ref>
<ref name="Howard">{{cite journal |last1=Howard |first1=Edward |date=1802 |title=Experiments and Observations on certain stony and metalline Substances, which at different Times are said to have fallen on the Earth; also on various Kinds of native Iron |url=https://books.google.com/books?id=oAVGAAAAMAAJ&pg=PA168 |journal=Philosophical Transactions of the Royal Society of London |volume=92 |pages=168–212 |bibcode=1802RSPT...92..168H |doi=10.1098/rstl.1802.0009 |doi-access=free}}</ref>
Line 241:
Line 241:
[[Category:1827 deaths]]
[[Category:1827 deaths]]
[[Category:18th-century German physicists]]
[[Category:18th-century German physicists]]
[[Category:People from the Electorate of Saxony]]
[[Category:Scientists from the Electorate of Saxony]]
[[Category:Musicians from the Electorate of Saxony]]
[[Category:Scientists from Wittenberg]]
[[Category:Scientists from Wittenberg]]
[[Category:German people of Slovak descent]]
[[Category:German people of Slovak descent]]
Latest revision as of 05:43, 22 December 2025
Template:Short descriptionScript error: No such module "redirect hatnote".Script error: No such module "Unsubst".Script error: No such module "Template wrapper".Script error: No such module "Check for clobbered parameters".
Ernst Florens Friedrich Chladni (Template:IPAc-en, Template:IPAc-en, Script error: No such module "IPA".; 30 November 1756 – 3 April 1827) was a Germanphysicist 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.[1] He also undertook pioneering work in the study of meteorites and is regarded by some as the father of meteoritics.[2]
Chladni came from an educated family of academics and learned men. Chladni's great-grandfather, the Lutheran clergyman Georg Chladni (1637–1692), had left Kremnica in 1673 during the Counter Reformation. Chladni's grandfather, Martin Chladni (1669–1725), was also a Lutheran theologian and, in 1710, became professor of theology at the University of Wittenberg. He was dean of the theology faculty in 1720–1721 and later became the university's rector. Chladni's uncle, Justus Georg Chladni (1701–1765), was a law professor at the university.Script error: No such module "Unsubst".
Another uncle, Johann Martin Chladni (1710–1759), was a theologian, a historian and a professor at the University of Erlangen and the University of Leipzig.
Chladni's father, Ernst Martin Chladni (1715–1782), was a law professor and rector of the University of Wittenberg. He had joined the law faculty there in 1746.Script error: No such module "Unsubst". Chladni's mother was Johanna Sophia and he was an only child.[7] His father disapproved of his son's interest in science and insisted that Chladni would become a lawyer.[6][8][9]
Career
Chladni studied law and philosophy in Wittenberg and Leipzig, obtaining a law degree from the University of Leipzig in 1782. That same year, his father died and he turned to physics in earnest.[8][9] He gave lectures on law, mathematics, and natural sciences at the University of Wittenberg from 1783 to 1792. During this time, he began his first experiments with acoustics.[6]
One of Chladni's best-known achievements was inventing a technique to show the various modes of vibration on a rigid surface, known as Chladni figures or Chladni patterns due to the various shapes or patterns created by various modes. When resonating, a plate or membrane is divided into regions that vibrate in opposite directions, bounded by lines where no vibration occurs (nodal lines). Chladni repeated the pioneering experiments of Robert Hooke who, on 8 July, 1680, had observed the nodal patterns associated with the vibrations of glass plates. Hooke ran a violin bow along the edge of a plate covered with flour and saw the nodal patterns emerge.[10][8][9][11] Hooke had already observed this 9 years earlier in 1671, and in turn was inspired by a suggestion he read in Bacon's Sylva Sylvarum, where Bacon describes rubbing the rim of a glass filled with water and observing the water "frisk and sprinkle". Hooke presented this in 1680 to the Royal Society, and there was no follow-up.[12]
Chladni's technique, first published in 1787 in his book Entdeckungen über die Theorie des Klanges ("Discoveries in the Theory of Sound"), consisted of drawing a bow over a piece of metal whose surface was lightly covered with sand. The plate was bowed until it reached resonance, when the vibration causes the sand to move and concentrate along the nodal lines where the surface is still, outlining the nodal lines. The patterns formed by these lines are what are now called Chladni figures. Similar nodal patterns can also be found by assembling microscale materials on Faraday waves.[13]
Chladni had visited the Paris Academy in 1808 and had demonstrated the vibration patterns before an audience that included not only the leading French scientists but Napoleon himself; Napoleon set a prize for the best mathematical explanation. Sophie Germain's answer, although rejected due to flaws, was the only entry with the correct approach.[14]
Variations of this technique are still commonly used in the design and construction of acoustic instruments such as violins, guitars, and cellos. 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 precise adjustable frequency.
In quantum mechanics, Chladni figures ("nodal patterns") are known to be related to the solutions of the Schrödinger equation for one-electron atoms, and the mathematics describing them was used by Erwin Schrödinger to arrive at the understanding of electron orbitals.[15]
Since at least 1738, a musical instrument called a Glasspiel or verrillon, created by filling beer glasses with varying amounts of water, was popular in Europe.[16] The beer glasses were struck by wooden mallets shaped like spoons to produce "church and other solemn music".[17]Benjamin Franklin was sufficiently impressed by a verrillon performance on a visit to London in 1757 that he created his own instrument, the glass harmonica, in 1762.
Franklin's harmonica inspired several other instruments, including two created by Chladni. In 1791, Chladni invented the musical instrument called the euphon (not to be confused with the brass instrument euphonium), consisting of glass rods used to play different pitches. Chladni's euphon is the direct ancestor of the modern day musical instrument known as the Cristal Baschet.[18] Chladni also improved on Hooke's "musical cylinder" to produce another instrument, the clavicylinder, in 1799.[8][9][17]
Chladni travelled throughout Europe with his instruments giving demonstrations.[6]
Contributions to meteoritics
Chladni became interested in meteoritics following a conversation he had with Georg Christoph Lichtenberg about a fireball that Lichtenberg supposedly saw in the Gӧttingen sky in November 1791. Inspired by this report, Chladni researched reports of similar phenomena as well as reports of other falling masses across Europe and North America within the last century. Based on the uniformity among these sightings, he concluded that the phenomena of fireballs and falling masses must be genuine.[19]
This led him to publish 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 1794. In this book he proposed that meteorites have an extraterrestrial origin.[20][21] He argued that this would explain the high speeds of the falling masses as well as linking the masses to the fireballs; they glow intensely bright as they enter the Earth's atmosphere. He hypothesized that these meteorites were chunks of material that had either never been consolidated in the formation of larger masses or were debris from the formation and destruction of planets.[19] This was a controversial statement at the time,[22] since meteorites were thought to be of volcanic origin. Additionally, his claims challenged the established belief that nothing existed beyond the Moon except for other stars and planets. Indeed, this supposed emptiness of space had fascinated Chladni as a child when he learned about the relatively large distance between Mars and Jupiter, where the Asteroid Belt is now known to exist. This observation factored into his account for the origins of meteorites.[19]
Chladni's book was initially ridiculed by contemporary physicists, including Lichtenberg.[23] Still, his writings sparked a curiosity that eventually led to more researchers supporting his theory. In 1795, a large stony meteorite was observed during its fall to Earth at a cottage near Wold Newton in Yorkshire, England and a piece of it, known as the Wold Cottage meteorite, was given to the BritishchemistEdward Howard who, along with FrenchmineralogistJacques de Bournon, carefully analyzed its composition and concluded that an extraterrestrial origin was likely, noting that the sample bore a strong resemblance to a sample of a meteorite from an early meteor shower in Siena, Italy.[24] Although that event had been attributed to an eruption of Mount Vesuvius a few hundred kilometers away, no similar volcanoes exists within the same range of Wold Newton, with the closest being Hekla in Iceland.[23][24] In 1803, the physicist and astronomerJean Baptiste Biot was commissioned by the French Minister of the Interior to investigate a meteor shower over L'Aigle in northern France that had peppered the town with thousands of meteorite fragments.[25][26][8][9] Unlike Chladni's book and the scientific publication by Howard and de Bournon, Biot's lively report became popular and persuaded more people to take Chladni's insights seriously.[21]
Chladni's insights have led some in the field to call him the "father of meteoritics" while others have been more conservative with their appraisal of Chladni's contributions to the field.[19]
Chladni continued to develop his record of meteorite sightings throughout the next several decades as well as amassing a collection of meteorite samples. He donated this collection to the Mineralogical Museum of Berlin University in 1827 and it now resides in the Museum of Natural History at Humboldt University of Berlin.[27][28]
Chladni discovered Chladni's law, a simple algebraic relation for approximating the modal frequencies of the free oscillations of plates and other bodies.[30]
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.[31] This built on work on measuring the speed of sound in air that Pierre Gassendi began in 1635.Script error: No such module "Unsubst".
↑ abcd"Life and work of E.F.F. Chladni", D. Ullmann1, The European Physical Journal – Special Topics, Springer, Berlin / Heidelberg, Template:Catalog lookup linkScript error: No such module "check isxn".Script error: No such module "check isxn".Script error: No such module "check isxn".Script error: No such module "check isxn".Script error: No such module "check isxn".Script error: No such module "check isxn".Script error: No such module "check isxn".Script error: No such module "check isxn".Script error: No such module "check isxn". (Print) Template:Catalog lookup linkScript error: No such module "check isxn".Script error: No such module "check isxn".Script error: No such module "check isxn".Script error: No such module "check isxn".Script error: No such module "check isxn".Script error: No such module "check isxn".Script error: No such module "check isxn".Script error: No such module "check isxn".Script error: No such module "check isxn". (Online), Issue Volume 145, Number 1, June 2007, Script error: No such module "CS1 identifiers"., pp. 25–32
↑Galileo had observed vibrational patterns in a brass plate as early as 1638. See: Galilei, Galileo; Crew, Henry and de Salvio, Alfonso, trans. (first published in Italian 1638; 1914) Dialogues Concerning Two New Sciences New York City, New York, US: Macmillan Co. pp. 101–102. From p. 100: "As I was scraping a brass plate with a sharp iron chisel in order to remove some spots from it and was running the chisel rather rapidly over it, I once or twice, during many strokes, heard the plate emit a rather strong and clear whistling sound; on looking at the plate more carefully, I noticed a long row of fine streaks parallel and equidistant from one another."
↑J. Michael McBride, "Chladni Figures and One-Electron Atoms", Lecture #9, Freshman Organic Chemistry (CHEM 125) course, Open Yale Courses, Yale University, video recorded Fall 2008, accessed on YouTube, https://www.youtube.com/watch?v=5kYLE8GhAuE, 5 June 2016.
↑ abcdScript error: No such module "Citation/CS1".
↑Chladni, Ernst Florens Friedrich, 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 natural phenomena associated with them] (Riga, Latvia: Johann Friedrich Hartknoch, 1794). Available on-line at: Saxon State and University Library at Dresden, Germany.
↑Knöfel, A., and J. Rendtel. "Chladni and the cosmic origin of fireballs and meteorites. Two hundred years of meteor astronomy and meteorite science." WGN, Journal of the International Meteor Organization 22 (1994): 217–219.
