Concept

Celestial spheres

Overview

The celestial spheres, or celestial orbs, were the fundamental entities of the cosmological models developed by Plato, Eudoxus, Aristotle, Ptolemy, Copernicus, and others. In these celestial models, the apparent motions of the fixed stars and planets are accounted for by treating them as embedded in rotating spheres made of an aetherial, transparent fifth element (quintessence), like gems set in orbs. Since it was believed that the fixed stars were unchanging in their positions relative to one another, it was argued that they must be on the surface of a single starry sphere.

Overview adapted from Wikipedia (CC BY-SA 4.0; see the article history for authors).

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Plato, for example, finds it agreeable to reason that the distances of the celestial spheres from one another should be proportional to the different lengths of strings which produce harmonious chords. Many philosophers have been led to their main conclusions by considerations like this; but this is the lowest and least developed form which the method takes, for it is clear that another man might find Kepler’s…
Charles S. Peirce, Chance, Love, and Logic
States what Celestial spheres is; names Celestial spheres twice.
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The universe revolves around a centre once in twenty-four hours, but the orbits of the fixed stars take a different direction from those of the planets. The outer and the inner sphere cross one another and meet again at a point opposite to that of their first contact; the first moving in a circle from left to right along the side of a parallelogram which is supposed to…
Plato, Timaeus
The author is tied to Celestial spheres in the knowledge graph.
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When we therefore perceive that all fixed stars move in the same way uniformly, without the least difference, we conclude that they are all in one sphere. It is, however, not impossible that the stars should have each its own sphere, with a separate centre, and yet move in the same way. If this theory be accepted, a number of Intelligences must be assumed, equal to that of the stars, and therefore Scripture says in…
Moses Maimonides, The guide for the perplexed
States what Celestial spheres is.
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Celestial spheres

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