At (Ancient Egypt)
| At in hieroglyphics | ||||||
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| New kingdom |
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| or |
At 3t time / moment (of the day ) |
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At (also At-Re ) was the ancient Egyptian name of a four-minute unit of time that was measured using the ancient Egyptian water clock . It was also the forerunner for the corresponding Mesopotamian time unit UŠ . An ancient Egyptian day consisted of 360 at-units; 180 each for the bright day and for the night.
The at units were used, among other things, for the temporal division of the dean stars on the diagonal star clocks . From an astronomical point of view , the movements of the stars could be measured precisely with simple means. For this purpose, the Egyptians made a so-called passage instrument , which was attached in a north-south direction parallel to the meridian . In this way the passage of the stars or the passage of the sun at noon could be observed and measured.
For a refinement of the technique for more accurate determination as units of time, the use of the ancient Egyptian water clock was also necessary for the first time under Amenhotep I is occupied.
See also
literature
- Friedrich Karl Ginzel : Handbook of mathematical and technical chronology, Vol. 1 - the time calculation of the Babylonians, Egyptians, Mohammedans, Persians, Indians, Southeast Asians, Chinese, Japanese and Central Americans - . German book export and import, Leipzig 1958 (Reprint Leipzig 1906)
- Richard Anthony Parker : Egyptian Astronomy, Astrology and calendrical reckoning In: Charles-Coulson Gillispie: Dictionary of scientific Biography - American Council of Learned Societies - Vol. 15, Supplement 1 (Roger Adams, Ludwik Zejszner: Topical essays) , Scribner, New York 1978, ISBN 0-684-14779-3 , pp. 706-727
- John-M. Steele : Observations and predictions of eclipse times by early Astronomers . Kluwer Academic Publications, Dordrecht 2000, ISBN 0-7923-6298-5 , p. 46.