View source for Ernst Chladni

{{Short description|German physicist, mathematician and musician}}
{{Redirect|Chladni|the lunar crater|Chladni (crater)}}
{{Lead too short|date=November 2024}}
{{ infobox scientist
| image             = Echladni.jpg
| image_size        = 150px
| birth_date        = {{birth-date|30 November 1756}}
| birth_place       = [[Wittenberg]], [[Electorate of Saxony]]
| death_date        = {{death-date and age|3 April 1827|30 November 1756}}
| death_place       = [[Breslau]], [[Kingdom of Prussia|Prussia]], [[German Confederation]]
| residence         = 
| citizenship       = 
| nationality       = [[Germany|German]]
| ethnicity         = 
| field             = [[Physics]]
| work_institutions = [[University of Erlangen]], [[University of Leipzig]]
| alma_mater        = 
| doctoral_advisor  = [[Georg Christoph Lichtenberg]]
| doctoral_students = [[Ernst Heinrich Weber]]
| known_for         = {{unbulleted list|style=white-space:nowrap; |Study of [[acoustics]] |Chladni plates and figures |Estimating the [[speed of sound]] |[[Chladni's law]] |Theory of [[meteorite]]s' origins}}
| influences        = 
| influenced        = 
| prizes            = 
| footnotes         = 
}}

'''Ernst Florens Friedrich Chladni''' ({{IPAc-en|UK|ˈ|k|l|æ|d|n|i}}, {{IPAc-en|US|ˈ|k|l|ɑː|d|n|i}}, {{IPA|de|ɛʁnst ˈfloːʁɛns ˈfʁiːdʁɪç ˈkladniː|lang}}; 30 November 1756&nbsp;– 3 April 1827) was a [[Germans|German]] [[physicist]] and [[music]]ian. His most important work, for which he is sometimes labeled the father of [[acoustics]], included research on [[Vibration|vibrating]] plates and the calculation of the [[speed of sound]] for different [[gas]]es.<ref name="Whipple"/> He also undertook pioneering work in the study of [[meteorite]]s and is regarded by some as the father of [[meteoritics]].<ref name="chladniite93"/>

== Early life ==
[[File:Chladni-1.jpg|thumb|left|Title page of a 1787 copy of ''"Entdeckungen über die Theorie des Klanges"'']]

Although Chladni was born in [[Wittenberg]] in [[Electorate of Saxony|Saxony]], his family originated from [[Kremnica]], then part of the [[Kingdom of Hungary]] and today a mining town in central [[Slovakia]]. Chladni has therefore been identified as [[German people|German]],<ref name="Britannica"/><ref name="scienceandsociety"/> [[Hungarian people|Hungarian]]<ref name="amsci"/> and [[Slovak people|Slovak]].<ref name="springer" />

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 [[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" />

== 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.<ref name="columbia"/><ref name="oxford"/> 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.<ref name="springer" />

== Chladni figures ==
[[File:Bowing chladni plate.png|thumb|left|Chladni's method of creating Chladni figures]]
[[File:Chladni pattern 1.jpg|thumb|Chladni figure on a rectangular plate supported in center]]
[[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"/> 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}}</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 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.<ref name="rm"/>

Variations of this technique are still commonly used in the design and construction of acoustic instruments such as [[violin]]s, [[guitar]]s, and [[cello]]s.  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.<ref name="McBride"/>

== Musical instruments ==
[[File:Chladni guitar.svg|thumb|Chladni patterns of a guitar backplate]]
[[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 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]]''.<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"/>

== 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 [[Göttingen|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.<ref name="Marvin"/>

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 [[Peter Simon Pallas|Pallas]] and Others Similar to it, and on Some Associated Natural Phenomena") in 1794. In this book he proposed that [[meteorite]]s have an [[Outer space|extraterrestrial]] origin.<ref name="Pallas"/><ref name="McSween"/> 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 [[planet]]s.<ref name="Marvin" /> This was a controversial statement at the time,<ref name="Williams"/> 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|Asteroid Belt]] is now known to exist. This observation factored into his account for the origins of meteorites.<ref name="Marvin" />

Chladni's book was initially ridiculed by contemporary physicists, including Lichtenberg.<ref name="Cowen"/> Still, his writings sparked a curiosity that eventually led to more researchers supporting his theory. In 1795, a large [[Meteorite classification#Stony meteorites|stony meteorite]] was observed during its fall to Earth at a cottage near [[Wold Newton, East Riding of Yorkshire|Wold Newton]] in [[Yorkshire]], [[England]] and a piece of it, known as the [[Wold Cottage meteorite]], was given to the [[British people|British]] [[chemist]] [[Edward Charles Howard|Edward Howard]] who, along with [[French people|French]] [[mineral]]ogist [[Jacques Louis, Comte de Bournon|Jacques 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|Siena, Italy]].<ref name="Howard"/> 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]].<ref name="Cowen" /><ref name="Howard" /> In 1803, the physicist and [[astronomer]] [[Jean Baptiste Biot]] was commissioned by the [[Minister of the Interior (France)|French Minister of the Interior]] to investigate [[L'Aigle (meteorite)|a meteor shower over L'Aigle]] in northern France that had peppered the town with thousands of meteorite fragments.<ref name="Biot-1"/><ref name="Biot-2"/><ref name="columbia" /><ref name="oxford" /> 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.<ref name=McSween />

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.<ref name="Marvin" />

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.<ref name="catalogue"/><ref name="Knöfel"/>

A mineral, first described in 1993 from the Carlton (IIICD) iron meteorite, was named {{interlanguage link|chladniite|ca|Chladniïta|eu|Chladniita|pl|Chladnit}} in his honor.<ref name="chladniite93" /><ref name="McCoy"/>

== Other work ==

Chladni discovered [[Chladni's law]], a simple algebraic relation for approximating the modal frequencies of the free oscillations of plates and other bodies.<ref name="Kverno"/>

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.<ref name="Weisstein"/> This built on work on measuring the speed of sound in air that [[Pierre Gassendi]] began in 1635.{{citation needed|date=April 2018}}

== Death ==

Chladni died on 3 April 1827, in [[Wrocław|Breslau]], [[Lower Silesia]], then part of the [[Kingdom of Prussia]] and today the city of Wrocław in southwestern [[Poland]].<ref name="Musielak2015"/>

== Works ==

* [[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: ''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}}).
* {{HathiTrust Catalog|id=007266663|title=Über den Ursprung der von Pallas gefundenen und anderer ihr ähnlicher Eisenmassen}}, Leipzig/Riga 1794.
* [https://archive.org/details/bub_gb_mQvXUlwvyeEC ''Über Feuermeteore''], Vienna 1820.
* [https://doi.org/10.1002/andp.18240760207 ''Über die Hervorbringung der menschlichen Sprachlaute''], Leipzig 1824.
* [https://link.springer.com/chapter/10.1007/978-3-662-24691-7_13 ''Kurze Übersicht der Schall und Klanglehre, nebst einem Anhange die Entwickelung und Anordnung der Tonverhältnisse betreffend''], Mainz 1827.

== Gallery ==
{{cleanup-gallery|date=April 2025}}

{| class="wikitable"
|+ Chladni plates
| 
[[File:Chladni plate 24.jpg|85px]]
[[File:Chladni plate 23.jpg|85px]]
[[File:Chladni plate 16.jpg|85px]]
[[File:Chladni plate 25.jpg|85px]]
[[File:Chladni plate 05.jpg|85px]]
[[File:Chladni plate 04.jpg|85px]]
[[File:Chladni plate 03.jpg|85px]]
[[File:Chladni plate 21.jpg|85px]]
[[File:Chladni plate 12.jpg|85px]]
[[File:Chladni plate 15.jpg|85px]]
[[File:Chladni plate 14.jpg|85px]]
[[File:Chladni plate 11.jpg|85px]]
[[File:Chladni plate 19.jpg|85px]]
[[File:Chladni plate 17.jpg|85px]]
[[File:Chladni plate 18.jpg|85px]]
[[File:Chladni plate 02.jpg|85px]]
[[File:Chladni plate 22.jpg|85px]]
[[File:Chladni plate 26.jpg|85px]]
[[File:Chladni plate 27.jpg|85px]]
[[File:Chladni plate 20.jpg|85px]]
[[File:Chladni plate 06.jpg|85px]]
[[File:Chladni plate 09.jpg|85px]]
[[File:Chladni plate 07.jpg|85px]]
[[File:Chladni plate 08.jpg|85px]]
|-
|
[[File:Prato de Chladni 01.webm|85px|rectangle]]
[[File:Prato de Chladni 02.webm|85px|rectangle]]
[[File:Prato de Chladni 03.webm|85px|rectangle]]
[[File:Prato de Chladni 04.webm|85px|rectangle]]
[[File:Prato de Chladni 05.webm|85px|rectangle]]
[[File:Prato de Chladni 06.webm|85px|rectangle]]
[[File:Prato de Chladni 07.webm|85px|triangle]]
[[File:Prato de Chladni 08.webm|85px|triangle]]
[[File:Prato de Chladni 09.webm|85px|triangle]]
[[File:Prato de Chladni 10.webm|85px|triangle]]
[[File:Prato de Chladni 11.webm|85px|triangle]]
[[File:Prato de Chladni 12.webm|85px|septagon]]
[[File:Prato de Chladni 13.webm|85px|septagon]]
[[File:Prato de Chladni 14.webm|85px|septagon]]
[[File:Prato de Chladni 15.webm|85px|septagon]]
[[File:Prato de Chladni 16.webm|85px|septagon]]
[[File:Prato de Chladni 17.webm|85px|disk]]
[[File:Prato de Chladni 18.webm|85px|septagon]]
[[File:Prato de Chladni 19.webm|85px|septagon]]
[[File:Prato de Chladni 20.webm|85px|septagon]]
[[File:Prato de Chladni 21.webm|85px|triangle]]
[[File:Prato de Chladni 22.webm|85px|triangle]]
[[File:Prato de Chladni 23.webm|85px|pentagon]]
[[File:Prato de Chladni 24.webm|85px|pentagon]]
[[File:Prato de Chladni 25.webm|85px|septagram]]
[[File:Prato de Chladni 26.webm|85px|septagram]]
[[File:Prato de Chladni 27.webm|85px|square]]
[[File:Prato de Chladni 28.webm|85px|square]]
[[File:Prato de Chladni 29.webm|85px|square]]
[[File:Prato de Chladni 30.webm|85px|square]]
[[File:Prato de Chladni 31.webm|85px|pentagon]]
[[File:Prato de Chladni 32.webm|85px|pentagon]]
|}

== See also ==

* {{anl|Alexander Lauterwasser}}
* {{anl|Bessel function}}
* {{anl|Hans Jenny (cymatics)}}
* {{anl|Tritare}}
* {{anl|Vibrations of a circular membrane}}

== References ==

{{refs|refs=
<ref name="Whipple">{{cite web |url=http://www.hps.cam.ac.uk/whipple/explore/acoustics/ernstchladni/ |publisher=University of Cambridge |access-date=27 February 2010 |title=Whipple Collections: Ernst Chladni}}</ref>
<ref name="chladniite93">{{cite journal |author=McCoy, T. J. |author2=Steele, I. M. |author3=Keil, K. |author4=Leonard, B. F. |author5=Endress, M. |title=Chladniite: A New Mineral Honoring the Father of Meteoritics |journal=Meteoritics |volume=28 |pages=394 |bibcode=1993Metic..28Q.394M |issue=3 |year=1993}}</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="amsci">{{cite journal |last1 = McLaughlin |first1 = Joyce |author-link = Joyce McLaughlin |year = 1998 |title = Good Vibrations |url = http://www.americanscientist.org/template/AssetDetail/assetid/15670;jsessionid=baa9...?fulltext=true |journal = [[American Scientist]] |volume = 86 |issue = 4 |page = 342 |doi = 10.1511/1998.4.342 |bibcode = 1998AmSci..86..342M |access-date = 2 November 2007 |archive-url = https://web.archive.org/web/20080123183514/http://www.americanscientist.org/template/AssetDetail/assetid/15670;jsessionid=baa9...?fulltext=true |archive-date = 23 January 2008 |url-status = dead }}</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''&nbsp;– 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="columbia">{{cite web | url = http://www.ilt.columbia.edu/projects/bluetelephone/html/chladni.html | title = Ernst Florens Friedrich Chladni | work = An Early History of the Telephone 1664-1865 | author = Daniel P McVeigh | year = 2000 | archive-url = https://web.archive.org/web/20130307235030/http://www.ilt.columbia.edu/projects/bluetelephone/html/chladni.html | archive-date = 7 March 2013 }}</ref>
<ref name="oxford">P. 101 Oxford Dictionary of Scientists&nbsp;– Oxford University Press&nbsp;– 1999</ref>
<ref name="Hooke-Diary">{{cite book |last1=Hooke |first1=Robert |editor1-last=Robinson |editor1-first=Henry W. |editor2-last=Adams |editor2-first=Walter |title=The Diary of Robert Hooke, M.A., M.D., F.R.S., 1672–1680 ... |date=1935 |publisher=Taylor & Francis |location=London, England |page=448}}</ref>
<ref name="Galileo">[[Galileo Galilei|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) [https://archive.org/details/dialoguesconcern00galiuoft/page/100 ''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."</ref>
<ref name="Chen">P. Chen, Z. Luo, S. Guven, S. Tasoglu, A. Weng, A. V. Ganesan, U. Demirci, Advanced Materials 2014, 10.1002/adma.201402079. http://onlinelibrary.wiley.com/doi/10.1002/adma.201402079/abstract</ref>
<ref name="rm">{{cite web|title=Revolutionary Mathematician|url=https://www.sdsc.edu/ScienceWomen/germain.html|publisher=[[San Diego Supercomputer Center]]|access-date=16 March 2016}}</ref>
<ref name="McBride">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.</ref>
<ref name="Schlesinger">{{Cite EB1911 |wstitle=Harmonica |volume=12 |page=956 |first=Kathleen |last=Schlesinger |author-link=Kathleen Schlesinger |quote=The 1911 edition of the ''[[Encyclopædia Britannica]]'' also credits [[Edward Delaval]] with inventing the verrillon.|short=1}}</ref>
<ref name="e1911">{{Cite EB1911 |wstitle=Harmonica |volume=12 |page=956 |first=Kathleen |last=Schlesinger |author-link=Kathleen Schlesinger}}</ref>
<ref name="Khazam">[http://www.mitpressjournals.org/doi/abs/10.1162/leon.2000.33.4.336 "Les Sculptures Sonores: The Sound Sculptures of Bernard and Francois Baschet" by Francois Baschet], Author(s) of Review: Rahma Khazam, ''[[Leonardo (journal)|Leonardo]]'', Vol. 33, No. 4 (2000), pp. 336–337</ref>
<ref name="Marvin">{{Cite journal|last=Marvin|first=Ursula B.|date=1996|title=Ernst Florens Friedrich Chladni (1756–1827) and the origins of modern meteorite research|journal=Meteoritics & Planetary Science|language=en|volume=31|issue=5|pages=545–588|doi=10.1111/j.1945-5100.1996.tb02031.x|bibcode=1996M&PS...31..545M|s2cid=210038676 |issn=1945-5100}}</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="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="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="Biot-1">{{cite journal|last1=Biot|first1=J.-B.|title=Relation d'un voyage fait dans le département de l'Orne pour constater la réalité d'un météore observé à l'Aigle le 6 floréal an XI|journal=Mémoires de la Classe des Sciences Mathématiques et Physiques de l'Institut National de France|date=1803|volume=7|pages=224–265|trans-title=Account of a trip made in the department of Orne to note the reality of a meteor observed at l'Aigle on 6 Floréal year XI|language=fr}}</ref>
<ref name="Biot-2">{{cite book|last1=Biot|first1=J.-B.|title=Relation d'un voyage fait dans le département de l'Orne pour constater la réalité d'un météore observé à l'Aigle le 6 floréal an XI|date=1803|publisher=Baudoin|location=Paris, France|url=https://books.google.com/books?id=JPwTAAAAQAAJ&pg=PA3|language=fr|trans-title=Account of a trip made in the department of Orne to note the reality of a meteor observed at l'Aigle on 6 Floréal year XI}}</ref>
<ref name="catalogue">{{Cite journal|last=Chladni|first=E. F. F.|date=10 August 2009|title=I. A new catalogue of meteoric stones, masses of meteoric iron, and other substances, the fall of which has been made known, down to the present time|journal=The Philosophical Magazine|volume=67|issue=333|pages=3–21|language=en|doi=10.1080/14786442608674005|url=https://zenodo.org/record/1756235}}</ref>
<ref name="Knöfel">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.</ref>
<ref name="McCoy">{{cite journal|last1=McCoy|first1=T.J.|last2=Steele|first2=I.M.|last3=Keil|first3=K.|last4=Leonard|first4=B.F.|last5=Endreβ|first5=M.|title=Chladniite, Na2CaMg7(PO4)6: A new mineral from the Carlton (IIICD) iron meteorite|journal=American Mineralogist|date=1994|volume=79|pages=375–380|bibcode=1994AmMin..79..375M}}</ref>
<ref name="Kverno">{{Cite web |url=http://www.phy.davidson.edu/StuHome/derekk/Chladni/pages/history.htm |title=History of Chladni's Law |last1=Kverno |first1=Derek |first2=Jim |last2=Nolen |publisher=[[Davidson College]] Physics Department |access-date=2 April 2018 |archive-date=17 October 2016 |archive-url=https://web.archive.org/web/20161017202842/http://www.phy.davidson.edu/StuHome/derekk/Chladni/pages/history.htm |url-status=dead }}</ref>
<ref name="Weisstein">[http://scienceworld.wolfram.com/biography/Chladni.html Chladni, Ernst (1756–1827)], ''Eric Weisstein's World of Scientific Biography''.</ref>
<ref name="Musielak2015">{{cite book|last=Musielak|first=Dora E.|author-link=Dora Musielak|title=Prime Mystery: The Life and Mathematics of Sophie Germain|url=https://books.google.com/books?id=KTUEDAAAQBAJ&pg=PA52|access-date=1 April 2018|date=23 January 2015|publisher=AuthorHouse|isbn=9781496965011|page=52}}</ref>
}}

== Further reading ==

* Jackson, Myles W. (2006) ''Harmonious Triads: Physicists, Musicians, and Instrument Makers in Nineteenth-Century Germany'' (MIT Press).
* {{cite journal |author=Marvin, Ursula B. |title=Ernst florens Friedrich Chladni (1756–1827) and the origins of modern meteorite research |year=1996 |journal=Meteoritics |volume=31 |pages=545–588 |bibcode=1996M&PS...31..545M|doi=10.1111/j.1945-5100.1996.tb02031.x |issue=5|s2cid=210038676 }}
* Rossing T. D. (1982) ''Chladni's Law for Vibrating Plates'', American Journal of Physics 50, 271–274

== External links ==
{{commonscategory|Ernst Florens Friedrich Chladni}}

* [http://vlp.mpiwg-berlin.mpg.de/references?id=per487 Short biography, bibliography, and links on digitized sources] in the [[Virtual Laboratory]] of the [[Max Planck Institute for the History of Science]]
* [https://web.archive.org/web/20080313072439/http://num-scd-ulp.u-strasbg.fr:8080/622/ ''Die Akustik''], 1802 by Ernst Chladni at Universities of Strasbourg
* {{YouTube|s9GBf8y0lY0|Video of Chladni patterns through frequency range}} (Accessed 5/31/08)
* {{YouTube|2OeLMu1u5E4|Simulated Chladni patterns on a rectangular plate}} (Accessed 5/18/14)
* [http://www.physics.utoronto.ca/nonlinear/chladni.html Examples with round, square, stadium plates and violin shapes]
* [https://web.archive.org/web/20051218024846/http://www.physics.montana.edu/demonstrations/video/3_oscillationandwaves/demos/chladniplates.html Chladni plates]
* [http://www.fas.harvard.edu/~scidemos/OscillationsWaves/BigChladniPlate/BigChladniPlate.html Electromagnetically driven Chladni plate]
* [http://www.violin-maker.co.uk/construction.html Use of Chladni patterns in the construction of violins]
* [http://www.phys.unsw.edu.au/~jw/guitar/guitarchladni_engl.html Chladni patterns for guitar plates]
* [https://demos.smu.ca/how-tos/104-chladni-patterns An explanation on how to construct a Chladni plate for the classroom]
* Other pictures of Chladni can be viewed at [https://web.archive.org/web/20071129122737/http://www-mech.eng.cam.ac.uk/dynvib/images/ernst.gif this site] and at the [http://www.scienceandsociety.co.uk/results.asp?image=10300907&wwwflag=2&imagepos=6 Science and Society Picture Library].
* {{cite web|last=Bowley|first=Roger|title=Chladni's Plate|url=http://www.sixtysymbols.com/videos/chladni.htm|work=Sixty Symbols|publisher=[[Brady Haran]] for the [[University of Nottingham]]|year=2009}}
* [http://monoskop.org/Ernst_Chladni Ernst Chladni at Monoskop.org]

{{Acoustics}}

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[[Category:1756 births]]
[[Category:1827 deaths]]
[[Category:18th-century German physicists]]
[[Category:Scientists from the Electorate of Saxony]]
[[Category:Musicians from the Electorate of Saxony]]
[[Category:Scientists from Wittenberg]]
[[Category:German people of Slovak descent]]
[[Category:Meteorite researchers]]
[[Category:19th-century German physicists]]
[[Category:Articles containing video clips]]