Pope Sylvester II applied the use of sighting tubes with his armillary sphere in order to fix the position of the pole star and record measurements for the tropics and equator, and used armillary spheres as a …

Armillary sphere, early astronomical device for representing the great circles of the heavens, including in the most elaborate instruments the horizon, meridian, Equator, tropics, polar circles, and an ecliptic …

Apr 29, 2025 · Armillary spheres are ancient tools used to model the movement of celestial objects in the sky. Armillary spheres date back to ancient Greece and China and became more sophisticated in …

With this demo you can explain the motions of the stars and of the Sun, and show various aspects of the seasons. The main features of the sphere itself are shown schematically in figure 1.

Aug 21, 2022 · The armillary sphere consists of several rings (armillaries) that represent important celestial circles, forming a cage with the Earth in the center. The spherical framework of rings sits on …

Jun 13, 2025 · One such method of demonstrating the movement of the celestial sphere is the armillary sphere. An armillary sphere is a model of the heavens featuring a central globe with a framework of …

Armillary spheres date back to the ancients, and were certainly used by the 2nd-century astronomer and mathematician Claudius Ptolemy of Alexandria. They were mathematical instruments designed to …

Some armillary spheres were used for observing the heavens and some, like this one, were used for teaching and demonstration (Image 1). They are made up of the circles or rings (Latin: armillae) that …

Dec 26, 2025 · An armillary sphere is an astronomical device made up of a number of rings linked to a pole. These rings represent the circles of the celestial sphere, such as the equator, the ecliptic and …

An armillary sphere is a model of objects in the sky, consisting of a spherical framework of rings, centered on Earth or the Sun, that represent lines of celest...