Editing Jean-Baptiste Biot

{{Short description|French physicist (1774–1862)}}
{{Infobox scientist
| name              = Jean-Baptiste Biot
| image             = Jean baptiste biot.jpg
| image_size        =
| caption           = Jean-Baptiste Biot
| birth_date        = {{birth-date|21 April 1774}}
| birth_place       = Paris, France
| death_date        = {{Death date and age|1862|2|3|1774|4|21|df=y}}
| death_place       = Paris, France
| residence         = 
| citizenship       = 
| nationality       = French
| ethnicity         = 
| field             = [[Physics]], [[astronomy]] and [[mathematics]]
| work_institutions = 
| alma_mater        = [[École Polytechnique]]
| doctoral_advisor  = <!--there were no PhDs in France before 1808-->
| academic_advisors = [[Gaspard Monge]]<ref>{{MacTutor Biography|id=Biot}}</ref>
| doctoral_students = 
| known_for         = [[Biot number]]<br>[[Biot–Savart law]]<br>[[Circular dichroism]]<br>[[Optical rotation]]
| prizes            = [[List of recipients of the Pour le Mérite for Sciences and Arts|Pour le Mérite]] {{small|(1850)}}<br>[[Rumford Medal]] {{small|(1840)}}<br>[[List of fellows of the Royal Society A, B, C#Foreign members|ForMemRS]] {{small|(1815)}}
| religion          = 
| footnotes         = 
| signature         = Signature of Jean-Baptiste Biot.svg 
}}
'''Jean-Baptiste Biot''' ({{IPAc-en|ˈ|b|iː|oʊ|,_|ˈ|b|j|oʊ}};<ref>[http://dictionary.reference.com/browse/biot+savart+law?qsrc=2446 "Biot-Savart law"]. ''[[Random House Webster's Unabridged Dictionary]]''.</ref> {{IPA|fr|bjo|lang}}; 21 April 1774 – 3 February 1862) was a [[French people|French]] [[physicist]], [[astronomer]], and [[mathematician]] who co-discovered the [[Biot–Savart law]] of magnetostatics with [[Félix Savart]], established the reality of [[meteorite]]s, made an early balloon flight, and studied the [[polarization (waves)|polarization of light]].

The [[Biot (unit)|biot]] (a [[CGS]] unit of electrical current), the mineral [[biotite]], and [[Cape Biot]] in eastern [[Greenland]] were named in his honour.

== Biography ==
Jean-Baptiste Biot was born in [[Paris]] on 21 April 1774 the son of Joseph Biot, a treasury official.<ref>{{Cite book |url=https://www.royalsoced.org.uk/cms/files/fellows/biographical_index/fells_indexp1.pdf |title=Former Fellows of The Royal Society of Edinburgh, 1783–2002: Part 1 (A–J) |author=C D Waterston |author2=A Macmillan Shearer |publisher=[[Royal Society of Edinburgh]] |isbn=090219884X |date=July 2006 |access-date=18 September 2015 |archive-date=24 January 2013 |archive-url=https://web.archive.org/web/20130124115814/http://www.royalsoced.org.uk/cms/files/fellows/biographical_index/fells_indexp1.pdf |url-status=dead}}</ref>

He was educated at Lyceum Louis-le-Grand and [[École Polytechnique]] in 1794.<ref>{{cite book|title=Appletons' annual cyclopaedia and register of important events of the year: 1862|date=1863|publisher=[[D. Appleton & Company]]|location=New York|page=683|url=https://archive.org/stream/1862appletonsan02newyuoft#page/n690/mode/1up}}</ref> Biot served in the [[artillery]] before he was appointed professor of mathematics at [[Beauvais]] in 1797. He later went on to become a professor of physics at the [[Collège de France]] around 1800, and three years later was elected as a member of the [[French Academy of Sciences]]. In July 1804, Biot joined [[Joseph Louis Gay-Lussac]] for the first scientific hot-air balloon ride to measure how the Earth's magnetic field varies with elevation (NNDB 2009, Reese 2004,<ref>{{Cite web |title=The Gay-lussac, Balloon Pioneer |url=https://cen.acs.org/articles/82/i25/Newscripts.html |access-date=2024-11-27 |website=Chemical & Engineering News |language=en}}</ref> O'Connor and Robertson 1997). They reached a height of 4000 metres (13,100 feet) (NNDB 2009, Reese 2004).  Later, in Sept. 1804, a solo flight took  Gay-Lussac up to 7010 metres (23,000&nbsp;ft) (quite dangerous without supplementary oxygen (Reese 2004)).

Biot was also a member of the [[Legion of Honour]]; he was elected chevalier in 1814 and commander in 1849. In 1815, he was elected a Foreign Member of the [[Royal Society]] of London,<ref>{{cite web|url= https://collections.royalsociety.org/DServe.exe?dsqIni=Dserve.ini&dsqApp=Archive&dsqDb=Persons&dsqSearch=Code==%27NA3671%27&dsqCmd=Show.tcl|title= Fellow details|publisher= [[Royal Society]]|access-date= 19 May 2016|archive-date= 5 November 2018|archive-url= https://web.archive.org/web/20181105235858/https://collections.royalsociety.org/DServe.exe?dsqIni=Dserve.ini&dsqApp=Archive&dsqDb=Persons&dsqSearch=Code==%27NA3671%27&dsqCmd=Show.tcl|url-status= dead}}</ref> in 1816 a member of the [[Royal Swedish Academy of Sciences]], and 1822 a Foreign Honorary Member of the [[American Academy of Arts and Sciences]].<ref name=AAAS>{{cite web|title=Book of Members, 1780–2010: Chapter B|url=http://www.amacad.org/publications/BookofMembers/ChapterB.pdf|publisher=[[American Academy of Arts and Sciences]]|access-date=8 September 2016}}</ref> In addition, Biot received the [[Rumford Medal]] in 1840, awarded by the Royal Society in the field of thermal or optical properties of matter. (O’Connor and Robertson 1997). In 1850 Jean-Baptiste Biot published in the ''[[Journal des savants]]'' a 7-page memoir from his recollections of the period of the late 1790s and early 1800s concerning his encounters with [[Laplace]].<ref>{{cite journal|title=Review of ''Anecdote relative à M. de Laplace'' par Jean Baptiste Biot|journal=The Quarterly Review|volume=87|date=June 1850|pages=115–118|url=https://babel.hathitrust.org/cgi/pt?id=hvd.32044092628734;view=1up;seq=129}}</ref><ref>{{cite journal|author=Biot, J. B.|title=''Anecdote relative à M. de Laplace''|journal=Journal des savants|year=1816 |postscript=. Février 1850|pages=65–71|url=https://babel.hathitrust.org/cgi/pt?id=nyp.33433109997845;view=1up;seq=81}}</ref>

Jean-Baptiste Biot had a single son, [[Édouard Biot|Édouard Constant Biot]], an engineer and Sinologist, born in 1803. Edouard died in 1850 and his father made extraordinary efforts to ready for publication the second half of Edouard's last book, a reference translation of the Chinese classic [[Rites of Zhou|''Tcheou-li'']]. It had been left in manuscript, unfinished. To publish it in correct form, Jean-Baptiste Biot wrote, he had to  consult [[Stanislas Julien]], the famous Sinologist, but also, especially for the translation of the most difficult part, the [[Kaogongji]], he himself visited many workshops and questioned artisans and craftsmen about their methods and vocabulary in order to verify his son's work. Biot's translation remains to this day the only translation into a Western language of this book.

He died in [[Paris]] on 3 February 1862.

== Work ==

=== Electromagnetism ===
[[File:Biot - Essai de géométrie analytique, appliquée aux courbes et aux surfaces du second ordre, 1826 - 755044.tif |thumb|''Essai de géométrie analytique'', 1826]]
{{electromagnetism|Scientists}}
Jean-Baptiste Biot made many contributions to the scientific community in his lifetime – most notably in optics, magnetism, and astronomy. In 1804, he used lines of equal magnetic field intensity in an article authored together with the Prussian naturalist [[Alexander von Humboldt]].<ref>{{ cite book | last=Daum | first=Andreas W.|author-link=Andreas Daum | year=2024 | title=Alexander von Humboldt: A Concise Biography | location=Trans. Robert Savage. Princeton, N.J. | publisher=Princeton University Press |pages=106 | isbn=978-0-691-24736-6 }}</ref> The [[Biot–Savart law]] in magnetism is named after Biot and his colleague [[Félix Savart]] for their work in 1820.<ref>A joint Biot-Savart paper "Note sur le magnétisme de la pile de Volta" was published in the ''Annales de chemie et de physique'' in 1820.</ref> In their experiment they showed a connection between electricity and magnetism by "starting with a long vertical wire and a magnetic needle some horizontal distance apart [and showing] that running a current through the wire caused the needle to move" (Parsley).

=== Meteorites ===
In 1803 Biot was sent by the [[Académie française]] to report back on 3000 [[meteorites]] that fell on [[L'Aigle]], in [[Normandy]], France (see [[L'Aigle (meteorite)]]). He found that the meteorites, called "stones" at the time, were from outer space.<ref>J.B. Biot (1803) [https://books.google.com/books?id=JPwTAAAAQAAJ&pg=PA3 ''Relation d'un voyage fait dans le département de l'Orne, pour constater la réalité d'un météore observé à l'Aigle le 26 floréal an 11''] [Account of a journey made in the department of the Orne [River], in order to ascertain the reality of a meteor observed in l'Aigle on the 26th of Floréal in the year 11 [Note: The date "26 floréal" on the title page is a typographical error; the meteor shower actually occurred on '''6''' floréal (i.e., April 26, 1803) and everywhere else in the text the date "6 floréal" is given as the date of the meteor shower. (Paris, France:  Baudouin, 1803).</ref> With his report, Biot helped support the German physicist [[Ernst Chladni]]'s argument, published in 1794, that meteorites were debris from space.<ref>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>[[File:Jean-Baptiste Biot by Henri Victor Regnault, 1851.jpg|thumb|right|Biot in 1851]]
Prior to Biot's thorough investigation of the meteorites that fell near l'Aigle, France in 1803, very few truly believed that rocks found on Earth could have extraterrestrial origins. There were anecdotal tales of unusual rocks found on the ground after fireballs had been seen in the sky, but such stories were often dismissed as fantasy. Serious debate concerning the unusual rocks began in 1794 when Ernst Chladni published a book claiming that such rocks had an extraterrestrial origin (Westrum). Only after Biot was able to analyse the rocks at l'Aigle was it commonly accepted that the fireballs seen in the sky were meteors falling through the atmosphere. Since Biot's time, analysis of meteorites has resulted in accurate measurements of the chemical composition of the [[Solar System]]. The composition and position of meteors in the Solar System have also given astronomers clues as to how the Solar System formed.

=== Polarized light ===

In 1812, Biot turned his attention to the study of [[optics]], particularly the [[polarization (waves)|polarization]] of light. Prior to the 19th century, light was believed to consist of discrete packets called [[wikt:corpuscle|corpuscles]]. During the early 19th century, many scientists began to disregard the [[corpuscular theory]] in favor of the [[wave theory of light]]. Biot began his work on polarization to show that the results he was obtaining could appear only if light were made of corpuscles.

In 1815 he demonstrated that "polarized light, when passing through an organic substance, could be rotated clockwise or counterclockwise, dependent upon the optical axis of the material."<ref>Biot, J. B. (1815) [https://www.biodiversitylibrary.org/item/26553#page/196/mode/1up "Phenomene de polarisation successive, observés dans des fluides homogenes"] (Phenomenon of successive polarization, observed in homogeneous fluids), ''Bulletin des Sciences, par la Société Philomatique de Paris'', 190–192.</ref><ref>[http://micro.magnet.fsu.edu/optics/timeline/people/biot.html Jean-Baptiste Biot – Florida State University]</ref> His work in chromatic polarization and [[rotary polarization]] greatly advanced the field of optics, although it was later shown that his findings could also be obtained using the wave theory of light.<ref>Frankel 2009</ref>

Biot's work on the polarization of light has led to many breakthroughs in the field of optics. [[Liquid crystal displays]] (LCDs), such as television and computer screens, use light that is polarized by a filter as it enters the liquid crystal, to allow the liquid crystal to modulate the intensity of the transmitted light. This happens as the liquid crystal's polarisation varies in response to an electric control signal applied across it. [[Polarizer|Polarizing filters]] are used extensively in photography to cut out unwanted reflections or to enhance reflection.

=== Cream of Tartar ===
[[Potassium bitartrate]] was first discovered inside a wine container in Iran. The modern application of the substance began in 1768, and in 1832, Jean Baptiste Biot discovered the physical properties of [[cream of tartar]]. The item gained most of its popularity when the French began using it frequently in their cooking.

=== Arc measurement ===
In August 1806, he was commissioned by the [[Bureau des Longitudes]], together with [[François Arago]], to continue the [[arc measurement|measurement of a meridian arc]] in France and Spain begun by [[Jean Baptiste Joseph Delambre|Delambre]] and [[Pierre Méchain|Méchain]] (the [[meridian arc of Delambre and Méchain]]).

== Selected writings ==
[[File:Biot, Jean Baptiste – Notions élémentaires de statique, 1829 – BEIC 12147982.jpg|thumb|''Notions élémentaires de statique'', 1829]]

* [http://gallica.bnf.fr/notice?N=FRBNF37257980 Traité élémentaire d'astronomie physique] (Klostermann, 1810–1811)
* {{Cite book|title=Récherches expérimentales et mathématiques sur les mouvemens des molécules de la lumière autour de leur centre de gravité|volume=|publisher=Firmin Didot|location=Paris|year=1814|language=fr|url=https://gutenberg.beic.it/webclient/DeliveryManager?pid=740906}}
* [http://gallica.bnf.fr/notice?N=FRBNF30107176 Traité de physique expérimentale et mathématique]( Deterville, 1816)
* {{Cite book|title=Précis élémentaire de physique expérimentale|volume=1|publisher=Tipografia del Giornale Enciclopedico|location=Napoli|year=1818|language=it|url=https://gutenberg.beic.it/webclient/DeliveryManager?pid=12151669}}
* {{Cite book|title=Précis élémentaire de physique expérimentale|volume=2|publisher=Tipografia del Giornale Enciclopedico|location=Napoli|year=1818|language=it|url=https://gutenberg.beic.it/webclient/DeliveryManager?pid=12153022}}
* {{Cite book|title=Précis élémentaire de physique expérimentale|volume=4|publisher=Tipografia del Giornale Enciclopedico|location=Napoli|year=1818|language=it|url=https://gutenberg.beic.it/webclient/DeliveryManager?pid=12154369}}
* {{Cite book|title=Précis élémentaire de physique expérimentale|volume=5|publisher=Tipografia del Giornale Enciclopedico|location=Napoli|year=1818|language=it|url=https://gutenberg.beic.it/webclient/DeliveryManager?pid=12155836}}
* {{Cite book|title=Notions élémentaires de statique|volume=|publisher=Charles Louis Étienne Bachelier|location=Paris|year=1829|language=fr|url=https://gutenberg.beic.it/webclient/DeliveryManager?pid=12147982}}
* {{Cite book|title=Précis de l'histoire de l'astronomie planétaire écrit à l'occasion de la découverte de M. Le Verrier|volume=|publisher=Pietro Fiaccadori|location=Parma|year=1854|language=it|url=https://gutenberg.beic.it/webclient/DeliveryManager?pid=6549137}}
* [http://gallica.bnf.fr/notice?N=FRBNF30107153 Précis de l'histoire de l'astronomie chinoise] (impr. impériale, 1861)
* [http://gallica.bnf.fr/notice?N=FRBNF35395244 Études sur l'astronomie indienne et sur l'astronomie chinoise] (Lévy frères, 1862)
* [https://books.google.com/books?id=jm4tAAAAMAAJ&dq=%22Jean-Baptiste+Biot%22&pg=PA1 Mélanges scientifiques et littéraires] (Lévy frères, 1858)
* [https://archive.org/details/recherchessurpl02biotgoog/page/n42 <!-- pg=1 quote="Jean-Baptiste Biot". --> Recherches sur plusieurs points de l'astronomie égyptienne] (Didot, 1823)

== See also ==
*[[Abampere]]
*[[History of the metre]]
*[[Seconds pendulum]]

==Notes==
{{reflist|2}}

==References==
*Frankel, Eugene. "Corpuscular Optics and the Wave Theory of Light: The Science and Politics of Revolution in Physics." ''Social Studies of Science'' vol. 6, no 2. May 1976. Sage Publications, Ltd. 15 June 2009 <https://www.jstor.org/stable/284930>.
*Westrum, Ron. "Science and Social Intelligence about Anomalies: The Case of Meteorites." ''Social Studies of Science'' vol. 8, no.4 Nov. 1978. Sage Publications, Ltd. 15 June 2009 <https://www.jstor.org/stable/284819>.
*Parsley, Robert J. "THE BIOT-SAVART OPERATOR AND ELECTRODYNAMICS ON BOUNDED SUBDOMAINS OF THE THREE-SPHERE". University of Pennsylvania. <http://users.wfu.edu/parslerj/research/dissertation.parsley.pdf>

==Further reading==
* {{DSB |first=M.P. |last=Crosland |title=Biot, Jean-Baptiste |volume=2 |pages=133–140 }}
* {{Cite book | last = Gounelle | first = Matthieu | contribution = The meteorite fall at L 'Aigle and the Biot report: exploring the cradle of meteoritics | date = 2006 | publisher = [[Geological Society of London]] | pages = 73–89 | title = The History of Meteoritics and Key Meteorite Collections | editor-last = Gerald Joseph Home McCall |editor2=A. J. Bowden |editor3=Richard John Howarth | url = https://books.google.com/books?id=7SvtVoa1W-cC&q=The+history+of+meteoritics+and+key+meteorite+collections | isbn = 978-1-86239-194-9 }}
* {{cite journal | pmid = 14626764 |last = Levitt |first = Theresa |date=Sep 2003 |title = Biot's paper and Arago's plates. Photographic practice and the transparency of representation | volume = 94 |issue = 3 | journal = Isis | pages = 456–476 | doi=10.1086/380654|s2cid = 143943335 }}
* {{cite CE1913|wstitle=Jean-Baptiste Biot|volume=2|first=William |last=Fox}}
* {{cite EB1911|wstitle= Biot, Jean Baptiste|volume=3}}

==External links==
{{commons category|Jean-Baptiste Biot}}
{{wikiquote}}
* [https://web.archive.org/web/20100624074735/http://www.pasteurbrewing.com/colleagues/biographies/jean-baptiste-biot-1774-1862.html Short biography] at Pasteur Brewing

{{Académie française Seat 12}}

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[[Category:French civil engineers]]
[[Category:École Polytechnique alumni]]
[[Category:École des Ponts ParisTech alumni]]
[[Category:Corps des ponts]]
[[Category:1774 births]]
[[Category:1862 deaths]]
[[Category:Scientists from Paris]]
[[Category:19th-century French physicists]]
[[Category:French optical physicists]]
[[Category:18th-century French mathematicians]]
[[Category:19th-century French mathematicians]]
[[Category:Commanders of the Legion of Honour]]
[[Category:Fellows of the American Academy of Arts and Sciences]]
[[Category:Members of the Académie des Inscriptions et Belles-Lettres]]
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[[Category:Members of the Académie Française]]
[[Category:Members of the Royal Swedish Academy of Sciences]]
[[Category:Foreign members of the Royal Society]]
[[Category:Recipients of the Pour le Mérite (civil class)]]
[[Category:French Roman Catholics]]
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[[Category:French aviation record holders]]
[[Category:French fluid dynamicists]]