epicycle concept from the Astronomy knowledge base

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epicycle

subject fact

epicycle has definition Circular orbit of a body round a point that is itself in a circular orbit round a parent body. Such a system was formulated to explain some planetary orbits in the Solar System before they were known to be elliptical. has source: Abbot, D. 1984 Astronomers, Peter Bedrick Books, New York, 2001-09-27 09:34:04.0
has definition In Ptolemaic cosmology a circular orbit around a point that itself orbits another point. has source: Ferris, T. 1988 Coming of Age in the Milky Way, Morrow, 2001-09-27 09:34:04.0
has definition A means of accounting for the apparent motions of the planets in terms of circular motions in a geocentric cosmology. Each planet moves in a circle, the center of which moves in a circle of larger radius, and so on, the largest circles being centered on the earth. has source: Silk, J. 1990 The Big Bang, W. H. Publishers, New York, 2001-09-27 09:34:04.0
is a kind of outdated belief

epicycle	has definition Circular orbit of a body round a point that is itself in a circular orbit round a parent body. Such a system was formulated to explain some planetary orbits in the Solar System before they were known to be elliptical.
	has definition In Ptolemaic cosmology a circular orbit around a point that itself orbits another point.
	has definition A means of accounting for the apparent motions of the planets in terms of circular motions in a geocentric cosmology. Each planet moves in a circle, the center of which moves in a circle of larger radius, and so on, the largest circles being centered on the earth.
	is a kind of outdated belief