John Playfair
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.
Life and work
In mathematics, John Playfair is mainly known for his work in the field of geometry. He wrote a very popular time of his annotated edition of the works of Euclid and gave 1795 an alternative formulation of the parallel axiom, which has since been referred to as Playfair cal parallel axiom. He was also one of the first mathematicians, who taught the modern Analysis in the UK.
In the geosciences Playfair is mainly through its support of James Hutton known, whose research first revealed the slowness of geological processes, but also that they persist until today ( actualism ). Playfair accompanied Hutton for many excursions, for example to the North Sea coast, where she discordant layering two rocks noticed on a rock - a reference to long-term deformations of the earth's crust.
On a trip to the Alps ( like his ue Switzerland map suggests, in the Bernese Alps ) should he have there examined erratics. He also found in Scotland, and came in 1802 to the conclusion that they have been transported by glaciers to their present locations. In contrast, it took even longer in Germany, the doctrine that a great flood would be the cause of erratic boulders.
So Leopold writes book of 1815 on the distribution of large alpine boulder and expressed a mud flood theory. In contrast, reported Jean de Charpentier in the same year on a conversation with a Swiss mountain farmers. The locals had long been clear that the lying in the valley of strange rocks had come from the glacier - the former seems much handed down.
Playfair gave Hutton's death out the 3rd edition of his " Theory of the Earth" and other writings. Huttons textbook he added with a summary and own images to make the difficult style easier to read.
In 1807 he was admitted as a member ( "Fellow" ) to the Royal Society.
In his honor, the lunar crater Playfair and 1967 the mineral Playfairit in 1935 named after him. His brother is well-known engineer and economist William Playfair.
Further works by Playfair
- Biography of James Hutton ( 1805)
- Illustrations of the Huttonian Theory of the Earth (1802, 6XX 528 p; facsimile printing. University of Illinois Press, Urbana, 1956 With an introduction by George W. White )
- SWITZERLAND. Drawn and engraved for Dr. Playfair 's Atlas. ( 1800; map of the eastern and partly Western Switzerland, 48x60 cm, engraved probably for the purpose of Glaciology )