(In ancient and medieval astronomy) a transparent sphere of the heavens postulated to lie between the fixed stars and the primum mobile and to account for the precession of the equinox and other motions.
More example sentences
- In 1618, he observed three comets pass effortlessly through Ptolemy's crystalline spheres (in which the planets and stars supposedly moved around the Earth), showing that these spheres must be imaginary.
- Peurbach believed that the planets were in solid crystalline spheres although he believed that their motions were controlled by the Sun.
- Aristotle's view of the world was based on a spherical Earth round which there were crystalline spheres which carried the Sun, Moon and planets.
Definition of crystalline sphere in:
- The US English dictionary