Playfair , John
(1748–1819) Scottish mathematician and geologist
Born at Benvie in Scotland, Playfair studied at St. Andrews University before becoming minister of Liff and Benvie in 1773. He was made a professor of mathematics at Edinburgh University in 1785 and professor of natural philosophy in 1805.
Playfair was a friend of the geologist James Hutton and in hisIllustrations of the Huttonian Theory of the Earth (1802) he amplified and explained Hutton's uniformitarian ideas. Hutton's own work had been notoriously hard to follow and Playfair brought uniformitarianism to a considerably larger public. He also pioneered the idea that a river carves out its own valley.
Although he is better known as a geologist Playfair did make contributions of note to mathematics, in particular to geometry. In 1795 he published his Elements of Geometry in which he set out an alternative version of Euclid's fifth postulate, which, given the truth of the other postulates, is equivalent to Euclid's original formulation. This postulate is consequently now known asPlayfair's axiom and asserts that for any line (L) and point (P) not on L there is one and only one line L' through P parallel to L.

Scientists. . 2011.

Look at other dictionaries:

  • Playfair, John — ▪ Scottish geologist and mathematician born March 10, 1748, Benvie, Forfarshire, Scot. died July 20, 1819, Burntisland, Fife       Scottish geologist and mathematician known for his explanation and expansion of ideas on uniformitarianism the… …   Universalium

  • PLAYFAIR, JOHN —    Scotch mathematician, born at Benvie; bred for the Church, became professor first of Mathematics and then of Natural Philosophy at Edinburgh University; wrote on geometry and geology, in the latter supported the Huttonian theory of the earth… …   The Nuttall Encyclopaedia

  • Playfair — John …   Scientists

  • John Playfair — (10 mars 1748 20 juillet 1819) est un scientifique écossais né à Benvie (Angus). Il est surtout connu pour avoir vulgarisé l œuvre de son compatriote James Hutton sur la théo …   Wikipédia en Français

  • John Playfair — John Playfair. John Playfair (* 10 de marzo de 1748 20 de julio de 1819) fue un matemático y geólogo escocés. Fue primer presidente de la Astronomical Institution of Edinburgh, fundada en 1811 (9 años más antigua que la Royal Astronomical… …   Wikipedia Español

  • Playfair Cricket Annual — is a compact cricket annual. It is a reference book primarily covering first class cricket in England. Its small size (3⅞ in by 5½ in, 10 cm by 14 cm) makes it ideal for taking to cricket matches. The core of the publication is the register of… …   Wikipedia

  • John Playfair — Portrait von Henry Raeburn John Playfair (* 10. März 1748 in Benvie (bei Dundee), Schottland; † 20. Juli 1819 in Burntisland, Fife, Schottland) war ein schottischer Mathematiker und …   Deutsch Wikipedia

  • Playfair (Begriffsklärung) — Playfair bezeichnet das Verschlüsselungsverfahren Playfair und ist der Name von folgenden Personen Ian Stanley Ord Playfair (1894–1972), britischer Militärhistoriker und Major General der British Army Jim Playfair (* 1964), kanadischer… …   Deutsch Wikipedia

  • John Leslie (físico) — John Leslie Nacimiento 16 de abril de 1766 Largo, Fife, Escocia Fallecimiento 3 de noviembre de 1832 Cerca de Largo, Fife, Escocia Residencia Es …   Wikipedia Español

  • John Stevens Henslow — Nacimiento 1796 Rochester Fallecimiento 1861 Hitcham …   Wikipedia Español

Share the article and excerpts

Direct link
Do a right-click on the link above
and select “Copy Link”