Armillary Sphere Facts

Armillary Sphere Facts
An armillary sphere is a model of the objects in the celestial sphere (imaginary sphere around the earth). The sphere contains a ring framework that represents celestial lines of longitude and latitude. The armillary sphere was invented in Ancient Greece and separately in ancient China as well. When the center of the armillary sphere is the sun, the tool is referred to as Copernican. When the earth is the center of an armillary sphere it is referred to as Ptolemaic. Eratosthenes (276 -192 BC) was credited with inventing the armillary sphere by Hipparchus, a Greek astronomer (190 -120 BC). The word armillary is derived from the Latin word 'armilla' which means 'circle or bracelet'.
Interesting Armillary Sphere Facts:
The armillary sphere has rings that represent the parallels, meridians, the ecliptic, and the equator, and linking the poles.
In the center of an armillary sphere is either the earth or the sun. This helps to demonstrate the stars' movement around the earth.
Prior to the development of the European telescope in the 1600s, the armillary sphere was the main astronomical instrument for determining the position of celestial objects.
The first armillary sphere is believed to have had one ring representing the equator, and was referred to as an armilla. Another ring was added in the plane of the meridian as time went on and the understanding of the earth and celestial sphere grew.
It wasn't until several rings were added that the tool became known as an armillary sphere.
It is believed that Hipparchus likely used an armillary sphere containing only four rings.
In the 3rd century BC the Greeks were already using armillary spheres as teaching tools.
In the 8th century the Arab and Persian astronomers improved upon the armillary sphere created by the Greeks, and one such instrument is believed to have been given to Caliph Muhammad I.
In the Middle Ages in the Islamic world the astrolabe and armillary sphere were combined to create the spherical astrolabe. Its inventor was Nayrizi.
In the 900s the armillary sphere was introduced to Western Europe.
During the Renaissance the armillary sphere was further advanced by Tycho Brahe (1546-1601), a Danish nobleman, astronomer, and astrologer.
Armillary spheres are considered to be some of the earliest most complex devices, which led to the improvement of many mechanical devices through advances in design and techniques.
Some refer to the armillary sphere as a skeleton of a celestial globe.
In China armillary spheres first appeared during the Han Dynasty, with one armillary sphere traced to the Eastern Han Dynasty (25 AD - 220 AD) to an astronomer Zhang Heng.
The early armillary spheres also depicted the early inaccuracies in regards to understanding how the universe works. The armillary spheres put the earth as the center of the universe.
Armillary spheres are depicted in artwork and sculptures dating back centuries and can be seen on display at museums around the world.
The armillary sphere is represented on the flag of Portugal. It is a symbol for the Portuguese Empire and discoveries by the Portuguese throughout history.

Related Links:
Facts
Astrological Instruments Facts
Animals Facts