Yvon Villarceau

Villarceau

Antoine-François-Joseph Yvon Villarceau (born January 15, 1813 in Vendôme , † December 23, 1883 in Paris ) was a French astronomer. After Ernest Lebon , he was one of the most important astronomers at the Paris Observatory during the time of Urbain Le Verrier as director, who particularly endeavored to combine theory and observation.

Life

Villarceau came to Paris in 1830, where he successfully attended the Conservatory of Music. In 1833 he joined a scientific expedition to Egypt, where he met the engineer Charles Lambert-Bey (1804–1864) and became interested in natural science and engineering. On his return in 1837, he began to study at the École Centrale des Arts et Manufactures, which he graduated as the best in mechanics. Since he was financially independent, he did not have to look for a job. He dealt with applied mathematics and astronomy and a work on orbital computation of comets, which he presented to the Academy of Sciences in 1845, found the attention of François Arago , who placed him at the Paris Observatory . There he began as an astronomer in 1846 and, among other things, constructed observation devices for the observatory and provided the theoretical preparatory work (e.g. compensation of chronometers, equatorial mounting ) and developed methods for calculating the orbit of comets and asteroids. He correctly predicted the return of the comet 6P / d'Arrest found by Heinrich Louis d'Arrest in Leipzig in 1851 , which could be observed in 1857 thanks to his prediction. In 1849 he improved a method for determining the orbits of the planets by Pierre Simon de Laplace . He dealt with the prediction of the orbits of double stars and astronomical aberration (determination of the speed of light, upper limit for the sun's own speed). He also dealt with the determination of the shape of the earth and found indications of the annual variation in geographical latitude (due to fluctuations in the earth's axis ). He also dealt with astronomical refraction as a major source of observation errors.

In 1855 he became a member of the Bureau des Longitudes and in 1867 of the Academie des Sciences .

The geometry of the Villarceau circles created by certain cutting planes through tori is named after him. As a civil engineer, he examined the statics of masonry arches using the example of bridges. ,

A street in the 16th arrondissement of Paris is named after him.

literature

• Ernest Lebon: Histoire Abrégée de l'Astronomie, Paris, Gauthier-Villars 1899, pp. 113–115, digitized, BNF

Fonts

• Mécanique Céleste. Exposé des Méthodes de Wronski et Composantes des Forces Perturbatrices suivant les Axes Mobiles, Paris: Gauthier-Villars, 1881
• Sur l'établissement des arches de pont, envisagé au point de vue de la plus grande stabilité, Paris: Imprimerie Impériale, 1853

Web links

• French biography of Ernest Lebon (expanded version of his biography of Villarceau in his History of Astronomy), Imago Mundi
• Publications by Y. Villarceau in the Astrophysics Data System

Individual evidence

1. ↑ pont Villarceau, L'établissement the arches de, Compte Rendu Acad. Sci. 1854
2. ↑ Lynn T. Courtenay, The engineering of medieval cathedrals, Routledge 1997, p. 176