Jean-Victor Poncelet

Infobox_Scientist
name = Jean-Victor Poncelet

---

image_width = 250px
caption =
birth_date = birth date|1788|7|1|fd=y
birth_place = Metz, France
residence = Metz, France (later Paris, France)
nationality = French
death_date = death date and age|1867|12|22|1788|1|7|fd=y
death_place = Paris, France
field = Mathematics, engineering
work_institutions = École d’Application of Metz, University of Paris, École Polytechnique
alma_mater = École Polytechnique
doctoral_advisor = Gaspard Monge
doctoral_students =
known_for = "Traité des propriétés projectives des figures" (1822), "Introduction à la mécanique industrielle" (1829)
prizes =

Jean-Victor Poncelet (July 1, 1788 – December 22, 1867) was a French engineer and mathematician who served most notably as the commandant general of the École Polytechnique. He is considered a reviver of projective geometry, and his work "Traité des propriétés projectives des figures" is considered the first definitive paper on the subject since Gérard Desargues' work on it in the 17th century. He later wrote an introduction to it; "Applications d’analyse et de géométrie".cite encyclopedia|encyclopedia=Encyclopædia Britannica|title=Jean-Victor Poncelet|url=http://www.britannica.com/EBchecked/topic/469548/Jean-Victor-Poncelet|accessdate=2008-04-19|year=2008|publisher=Encyclopædia Britannica, Inc]

As a mathematician, his most notable work was in projective geometry , in particular, his work on Feuerbach's theorem. He also made discoveries about projective harmonic conjugates; among these were the poles and polar lines associated with conic sections. These discoveries led to the principle of duality, and also aided in the development of complex numbers and projective geometry.cite encyclopedia|encyclopedia=Encyclopædia Britannica|title=Jean-Victor Poncelet|url=http://www.britannica.com/EBchecked/topic/469548/Jean-Victor-Poncelet|accessdate=2008-04-19|year=2008|publisher=Encyclopædia Britannica, Inc]

As an military engineer, he served in Napoleon's campaign against the Russian Empire in 1812, in which he was captured and held prisoner until 1814. Later, he served as a professor of mechanics in his home town of Metz. At this position, he developed improved the design of turbines and water wheels. He then served as a professor of mechanics at the École d’Application there, during which time he published "Introduction à la mécanique industrielle", a work he is famous for. After this, he served as professor at the Faculté des Sciences at the University of Paris, and finally as the commandant general of his "alma mater", the École Polytechnique.cite encyclopedia|encyclopedia=Encyclopædia Britannica|title=Jean-Victor Poncelet|url=http://www.britannica.com/EBchecked/topic/469548/Jean-Victor-Poncelet|accessdate=2008-04-19|year=2008|publisher=Encyclopædia Britannica, Inc]

Biography

Birth, education, and capture (1788–1814)

Poncelet was born in Metz, France, on July 1, 1788; the illegitimate son of Claude Poncelet, a lawyer of the Parliament of Metz, and a wealthy landowner.cite encyclopedia|author=Kimberly A. McGrath|encyclopedia=World of Scientific Discovery|title=Jean-Victor Poncelet|year=2006|publisher=Thomson Gale|city=Detroit] At a young age, he was sent to live with the Olier family at Saint-Avold.Didion 1870, p. 102] Returning to Metz for secondary education, he attended the lycée in his hometown.cite encyclopedia|author=Kimberly A. McGrath|encyclopedia=World of Scientific Discovery|title=Jean-Victor Poncelet|year=2006|publisher=Thomson Gale|city=Detroit] After this, he attended the École Polytechnique, a prestigious French school located in Paris, from 1808 to 1810, though he fell behind in his studies in his third year due to poor health.cite encyclopedia|author=Kimberly A. McGrath|encyclopedia=World of Scientific Discovery|title=Jean-Victor Poncelet|year=2006|publisher=Thomson Gale|city=Detroit] After graduation, he joined the Corps of Military Engineers. He attended the Ècole d'Application in his hometown during this time, and achieved the rank of lieutenant in the French Army the same year he graduated.cite web|title=Jean-Victor Poncelet biography|url=http://www-groups.dcs.st-and.ac.uk/~history/Biographies/Poncelet.html|accessdate=2008-04-19|author=John J O'Connor and Edmund F Robertson]

Poncelet took part in Napololeon's invasion of Russia in 1812. His biographer Didion writes that he was part of the group that did not follow Marshall Michel Ney at the Battle of Krasnoi, which was forced to capitulate to the Russians, though other sources say that he was left for dead.cite encyclopedia|author=Kimberly A. McGrath|encyclopedia=World of Scientific Discovery|title=Jean-Victor Poncelet|year=2006|publisher=Thomson Gale|city=Detroit] Upon capture, he was interrogated by General Mikhail Andreyevich Miloradovich but he did not disclose any information.Didion 1870, p. 166] . The Russians took Poncelet as a prisoner of war and confined him at Saratov [cite web|url=http://scienceworld.wolfram.com/biography/Poncelet.html|accessdate=2008-05-31|author=Eric W. Weisstein|year=1996|title=Poncelet, Jean-Victor] During his imprisonment, in the years 1812–1814, he wrote his most notable work; "Traité des propriétés projectives des figures". This work outlined the foundations of projective geometry, as well as some new results. Poncelet, however, could not publish it until after his release in 1814.cite encyclopedia|encyclopedia=Encyclopædia Britannica|title=Jean-Victor Poncelet|accessdate=2008-04-19|year=1911|publisher=Encyclopædia Britannica, Inc|volume=22|page=59]

Release and later employment (1822–1848)

In 1815, the year after his release, Poncelet was employed a military engineer at his hometown of Metz. In 1822, while at this position, he published "Traité des propriétés projectives des figures". This work was the first major to discuss projective geometry since Desargues', though Gaspard Monge had written a few minor works about it previously. It is considered the founding work of modern projective geometry.cite web|title=Jean-Victor Poncelet biography|url=http://www-groups.dcs.st-and.ac.uk/~history/Biographies/Poncelet.html|accessdate=2008-04-19|author=John J O'Connor and Edmund F Robertson] Joseph Diaz Gergonne wrote about this branch of geometry at approximately the same time, beginning in 1810. Poncelet published several papers about the subject in Gergonne's mathematical journal "Annales de Gergonne" (officially known as "Annales de mathématiques pures et appliquées").cite encyclopedia|encyclopedia=Encyclopædia Britannica|title=Jean-Victor Poncelet|accessdate=2008-04-19|year=1911|publisher=Encyclopædia Britannica, Inc|volume=22|page=59]

In 1825, he became the professor of mechanics at the École d'Application in Metz, a position he held until 1835. During his tenure at this school, he improved the design of turbines and water wheels, deriving his work from the mechanics of the Provençal mill from southern France. [cite web|author=James B. Calvert|title=Turbines|accessdate=2008-05-20|publisher=University of Denver|url=http://mysite.du.edu/~jcalvert/tech/fluids/turbine.htm] Although the turbine of his design was not constructed until 1838, he envisioned such a design twelve years previous to that.cite encyclopedia|encyclopedia=Encyclopædia Britannica|title=Jean-Victor Poncelet|url=http://www.britannica.com/EBchecked/topic/469548/Jean-Victor-Poncelet|accessdate=2008-04-19|year=2008|publisher=Encyclopædia Britannica, Inc] In 1835, his tenure at the École d'Application ended, and in 1838 became a professor at the Faculté des Sciences in Paris.cite encyclopedia|publisher=Columbia University Press|encyclopedia=The Columbia Electronic Encyclopedia|edition=6|year=2007|accessdate=2008-04-19]

Commandant of École Polytechnique (1848–1867)

In 1848, Poncelet became dacommannt of his "alma mater"; the École Polytechnique, having a rank of general.Didion 1870, p. 101] He held the position until 1850, when he retired.cite encyclopedia|encyclopedia=Encyclopædia Britannica|title=Jean-Victor Poncelet|url=http://www.britannica.com/EBchecked/topic/469548/Jean-Victor-Poncelet|accessdate=2008-04-19|year=2008|publisher=Encyclopædia Britannica, Inc]

During this time, he wrote "Applications d'analyse et de géométrie", which served as an introduction to his earlier work "Traité des propriétés projectives des figures". It was published in two volumes in 1862 and 1864. [Bertrand 1879, p. 45]

Contributions

Poncelet-Steiner theorem

Poncelet suggested the following theorem in 1822: Euclidean compass and straightedge constructions can be carried out using only a straightedge if a single circle and its center is given. Swiss mathematician Jakob Steiner proved this theorem in 1833, leading to the name of the theorem. The constructions that this theorem states are possible are known as Steiner constructions. [mathworld|urlname=Poncelet-SteinerTheorem|title=Poncelet-Steiner Theorem]

List of selected works

* (1822) "Traité des propriétés projectives des figures"
* (1826) "Cours de mécanique appliqué aux machines"
* (1829) "Introduction à la mécanique industrielle"
* (1862/64) "Applications d'analyse et de géométrie"

ee also

*Poncelet, a unit of power named after him

Notes

References

*cite book|title=Notice sur la vie et les ouvrages du général J. V. Poncelet|last=Didion|first=M.|publisher=L'Académie nationale de Metz|year=1870 [http://visualiseur.bnf.fr/Visualiseur?Destination=Gallica&O=NUMM-33253] 1870 (50e année / 1868-1869; 2e série) pp. 101-159.
*cite book|title=Mémoires de l'Académie des Sciences|volume=41|last=Bertrand|first=J.|year=1879
*cite encyclopedia|first=René|last=Taton|encyclopedia=Dictionary of Scientific Biography|city=New York|year=1970|isbn=978-0684169705|title=Jean-Victor Poncelet|publisher=Gale Cengage

External links

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Persondata
NAME = Poncelet, Jean-Victor
ALTERNATIVE NAMES =
SHORT DESCRIPTION = French mathematician, physicist, and military engineer.
DATE OF BIRTH = July 1, 1788
PLACE OF BIRTH = Metz, France
DATE OF DEATH = December 22, 1867
PLACE OF DEATH = Paris, France