Armillary Sphere

An armillary sphere (variations are known as spherical astrolabe, armilla, or armil) is a model of objects in the sky (in the celestial sphere), consisting of a spherical framework of rings, centred on Earth, that represent lines of celestial longitude and latitude and other astronomically important features such as the ecliptic. As such, it differs from a celestial globe, which is a smooth sphere whose principal purpose is to map the constellations.

Read more about Armillary Sphere:  Description and Use of The Armillary Sphere

Other articles related to "armillary sphere, sphere, armillary spheres":

Armillary Sphere - History - Seamless Celestial Globe
... typically cast in two halves, and Savage-Smith indicates that the casting of a seamless sphere is considered impossible, though techniques such as Rotational molding have been used since at ...
Su Song's Escapement Mechanism
... Song credited, as the predecessor of his working clock, the hydraulic-powered armillary sphere of Zhang Heng (78–139 AD), an earlier Chinese scientist ... within the tower, rotated an observational armillary sphere on the top platform and a celestial globe in the upper story ... included conversion gearing, since it gave 'unequal' as well as equal time signals, and the sphere probably had this ...
Zhang Sixun
... He is credited with creating an armillary sphere for his astronomical clock tower that employed the use of liquid mercury (dripped periodically from a ... the effect of an escapement mechanism in clockworks and allow the astronomical armillary sphere to rotate as needed ... He designed the model for his armillary sphere in 976 and completed the creation of it in 977 ...
List Of Chinese Inventions - Shang and Later - A
... Armillary sphere, hydraulic-powered Hipparchus (c ... century AD) credited the Greek Eratosthenes (276–194 BC) as the first to invent the armillary sphere representing the celestial sphere ... first to apply motive power to the rotating armillary sphere by a set of complex gears rotated by a waterwheel which in turn was powered by the constant ...
Coat Of Arms Of Portugal - History and Meaning - Armillary Sphere
... element of Portuguese heraldry since the 15th century, the armillary sphere was many times used in Portuguese colonial flags, mainly in Brazil ... Kingdom of Portugal, Brazil and the Algarves, already depicted armillary spheres ... The incorporation of the armillary sphere into the 1816 flag of the United Kingdom of Portugal is related to the adoption of the first flag of the Kingdom of Brazil, an armillary sphere on a blue ...

Famous quotes containing the word sphere:

    It is in the nature of allegory, as opposed to symbolism, to beg the question of absolute reality. The allegorist avails himself of a formal correspondence between “ideas” and “things,” both of which he assumes as given; he need not inquire whether either sphere is “real” or whether, in the final analysis, reality consists in their interaction.
    Charles, Jr. Feidelson, U.S. educator, critic. Symbolism and American Literature, ch. 1, University of Chicago Press (1953)