Raoul Bricard

From Wikipedia, the free encyclopedia
Jump to: navigation, search

Raoul Bricard (23 March 1870 – 1944) is a French engineer and a mathematician. He is best known for his work in geometry, especially descriptive geometry and scissors congruence, and kinematics, especially mechanical linkages.

Biography[edit]

Bricard taught geometry at Ecole Centrale des Arts et Manufactures. In 1908 he became a professor of applied geometry at the National Conservatory of Arts and Crafts in Paris.[1] In 1932 he received Poncelet Prize in mathematics from the Paris Academy of Sciences for his work in geometry.[2]

Work[edit]

In 1896 Bricard published a paper on Hilbert's third problem, even before the problem was stated by Hilbert.[3] In it he proved that mirror symmetric polytopes are scissors congruent, and proved a weak version of Dehn's criterion.

In 1897 Bricard published an important investigation on flexible polyhedra.[4] In it he classified all flexible octahedra.[5] This work was the subject of Henri Lebesgue's lectures in 1938.[6] Later Bricard discovered notable 6-bar linkages.[7][8]

Bricard also gave one of the first geometric proofs of Morley's trisector theorem in 1922.[9][10]

Books[edit]

Bricard authored six books, including a mathematics survey in Esperanto.[11] He is listed in Encyclopedia of Esperanto.[12]

  • Matematika terminaro kaj krestomatio (in Esperanto), Hachette, Paris, 1905
  • Géométrie descriptive, O. Doin et fils, 1911
  • Cinématique et mécanismes, A. Colin, 1921
  • Petit traité de perspective, Vuibert, 1924
  • Leçons de cinématique, Gauthier-Villars et cie., 1926
  • Le calcul vectoriel, A. Colin, 1929

Notes[edit]

  1. ^ Science, vol. 28 (1908), p. 707.
  2. ^ "Prize Awards of the Paris Academy of Sciences", Nature vol. 131 (1933) 174-175.
  3. ^ R. Bricard, "Sur une question de géométrie relative aux polyèdres", Nouvelles annales de mathématiques, Ser. 3, Vol. 15 (1896), 331-334.
  4. ^ R. Bricard, Mémoire sur la théorie de l’octaèdre articulé, J. Math. Pures Appl., Vol. 3 (1897), 113–150 (see also the English translation).
  5. ^ P. Cromwell, Polyhedra, Cambridge University Press, 1997.
  6. ^ H. Lebesgue, "Octaedres articules de Bricard", Enseign. Math. Ser. 2, 13, No. 3, 175-185.
  7. ^ K. Wohlhart, The two types of the orthogonal Bricard linkage, Mechanism and machine theory, vol. 28 (1993), 809-817.
  8. ^ Bricard 6 Bar Linkage Origami on YouTube.
  9. ^ Richard K. Guy, "The Lighthouse Theorem, Morley & Malfatti - A Budget of Paradoxes", American Mathematical Monthly 114 (2007) 97-141.
  10. ^ Alain Connes, "Symmetries", European Mathematical Society Newsletter No. 54 (December 2004).
  11. ^ Raoul Bricard, from Open Library.
  12. ^ Encyclopedia of Esperanto

References[edit]

  • Laurent R., Raoul Bricard, Professeur de Géométrie appliquée aux arts, in Fontanon C., Grelon A. (éds.), Les professeurs du Conservatoire national des arts et métiers, dictionnaire biographique, 1794-1955, INRP-CNAM, Paris 1994, vol. 1, pp. 286–291.