Gnomonic
Gnomonik is the study of the sundial , from Greek γνώμων Gnomon " shadow stick ", the central part of an ancient sundial with the stick tip as a functional element.
useful information
Today research into the history of sundials is also part of the gnomonic. Like the first use of the sundial, it probably goes back to the Babylonians . However, it reached its peak in ancient Greece and Rome .
The Roman author Vitruvius names in his work "Ten books on architecture" (about 22 BC dedicated to the emperor Augustus) the gnomonic as one of the three sub-areas of architecture.
The gnomonic projection serves as an aid to calculate the shadow cast by the gnomon tip . This generally used geometric term for the central projection of a hollow sphere is used for the projection of the sun from the celestial sphere onto the dial of the sundial.
literature
- Joseph Johann von Littrow : Gnomonics, or instructions for the production of all kinds of sundials (Vienna 1833)
- Marcus Vitruvio Pollius : De architectura libri decem (Ten books on architecture), Latin - German translation with comments by Curt Fensterbusch, Primus Verlag 1996, ISBN 3-89678-005-0
- Karlheinz Schaldach: Roman Sundials: An Introduction to Ancient Gnomonics , 3rd Edition, Harri Deutsch, Frankfurt am Main 2001, ISBN 3-8171-1649-7 .
- Karl Schoy : Arabic Gnomonic . Altone 1913, DNB 571219187 (Scientific and mathematical dissertation University of Heidelberg 1913, 40 pages).
- Karl Schoy: The History of Time Measurement and Clocks , Part 1, Delivery F: Gnomonics of the Arabs . Association of Scientific Publishers de Gruyter, Berlin / Leipzig 1923, DNB 1003432484 .
- Josef Drecker: The history of time measurement and clocks , part 1, delivery E: The theory of sundials, Association of Scientific Publishers de Gruyter, Berlin / Leipzig 1925, DNB 1003432247 .
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