John Playfair

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John Playfair - portrait of Henry Raeburn

John Playfair (born March 10, 1748 in Benvie (near Dundee ), Scotland , † July 20, 1819 in Burntisland , Fife , Scotland) was a Scottish mathematician and geologist and professor of mathematics at the University of Edinburgh .

Live and act

In mathematics, John Playfair is best known for his work in the field of geometry. He wrote an annotated edition of the works of Euclid , which was very popular at the time , and in 1795 gave an alternative formulation of the parallel axiom , which has since been referred to as Playfair's parallel axiom . He was also one of the first mathematicians to teach modern analysis in Britain.

In the geosciences , Playfair is best known for its support from James Hutton , whose research first showed the slowness of geological processes, but also that they continue to this day ( actualism ). Playfair accompanied Hutton on many excursions , for example to the North Sea coast , where they noticed the discordant layering of two rocks on a rock - an indication of long-term warping of the earth's crust .

During a trip to the Alps (as his map of Switzerland suggests, also to the Bernese Alps ), he must have examined erratic blocks there. He also found them in Scotland and in 1802 concluded that they had been transported to their present-day locations by glaciers . On the other hand, in Germany the doctrine continued for a long time that a large flood must be the cause of the erratic boulders .

Memorial to John Playfair on Calton Hill , Edinburgh

Writes Leopold von Buch about the spread of large Alpine 1815 bedload and expresses a mud flood theory. In contrast, Jean de Charpentier reported on a conversation with a Swiss mountain farmer in the same year . The locals had long since realized that the strange rocks in the valley had to come from the glacier - which in the past apparently reached much further down.

After Hutton's death, Playfair published the third edition of his “Theory of the Earth” and other publications. He supplemented Hutton's textbook with a summary and his own illustrations to make the difficult style easier to read.

In 1807 he was accepted as a member (" Fellow ") in the Royal Society and in 1783 in the Royal Society of Edinburgh .

His 1935 lunar craters were honoring Playfair , 1967, the mineral Playfairit and 1968, Playfair Mountains in Antarctica named after him.

His brother is the well-known engineer and economist William Playfair .

More works by Playfair

  • Biography of James Hutton (1805)
  • Illustrations of the Huttonian Theory of the Earth (1802, 6XX + 528 p .; facsimile print: University of Illinois Press, Urbana 1956. With an introduction by George W. White)
  • SWITZERLAND. Drawn and engraved for Dr. Playfair's Atlas. (around 1800; map of eastern and partly also western Switzerland, 48 × 60 cm, engraved probably for the purposes of glaciology )

See also

Web links

Commons : John Playfair  - collection of pictures, videos and audio files

Individual evidence

  1. ^ Fellows Directory. Biographical Index: Former RSE Fellows 1783–2002. (PDF file) Royal Society of Edinburgh, accessed March 30, 2020 .
  2. ↑ Playfairite , in: John W. Anthony, Richard A. Bideaux, Kenneth W. Bladh, Monte C. Nichols (Eds.): Handbook of Mineralogy, Mineralogical Society of America , 2001 ( PDF 63.4 kB )
personal data
SURNAME Playfair, John
BRIEF DESCRIPTION Scottish mathematician and geologist
DATE OF BIRTH March 10, 1748
PLACE OF BIRTH Benvie (near Dundee ), Scotland
DATE OF DEATH July 20, 1819
Place of death Burntisland , Fife , Scotland