Ptolemaic system
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Related to Ptolemaic system: Ptolemy, Ptolemaic dynasty, Copernicus, Heliocentric System, Geocentric model
Ptolemaic system
n.
The astronomical system of Ptolemy, in which the earth is at the center of the universe with the sun, moon, planets, and stars revolving about it in circular orbits at increasing distance. Some of the orbits have epicycles.
American Heritage® Dictionary of the English Language, Fifth Edition. Copyright © 2016 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
Ptolemaic system
n
(Astronomy) the theory of planetary motion developed by Ptolemy from the hypotheses of earlier philosophers, stating that the earth lay at the centre of the universe with the sun, the moon, and the known planets revolving around it in complicated orbits. Beyond the largest of these orbits lay a sphere of fixed stars. See also epicycle1 Compare Copernican system
Collins English Dictionary – Complete and Unabridged, 12th Edition 2014 © HarperCollins Publishers 1991, 1994, 1998, 2000, 2003, 2006, 2007, 2009, 2011, 2014
Ptolema′ic sys`tem
n.
Ptolemy's conception of the universe, with the earth as the fixed center and the heavenly bodies moving about it.
Random House Kernerman Webster's College Dictionary, © 2010 K Dictionaries Ltd. Copyright 2005, 1997, 1991 by Random House, Inc. All rights reserved.
Ptolemy believed that Earth was at the center of the universe and that the sun and planets orbited Earth (with the planets also moving in smaller circles called epicycles). In this system, the centers of Mercury's and Venus's epicycles always lie on the line shown in the diagram between Earth and the sun.
Ptol·e·ma·ic system
(tŏl′ə-mā′ĭk) The astronomical system of Ptolemy, in which Earth is at the center of the universe and all celestial bodies revolve around it. The sun, moon, and planets revolve at different levels in circular orbits, and the stars lie in fixed locations on a sphere that revolves beyond these orbits.
The American Heritage® Student Science Dictionary, Second Edition. Copyright © 2014 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
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| Noun | 1. | Ptolemaic system - (astronomy) Ptolemy's model of the universe with the Earth at the center framework, model, theoretical account - a hypothetical description of a complex entity or process; "the computer program was based on a model of the circulatory and respiratory systems" |
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