Common questions about Armillary sphere

Short answers, pulled from the story.

What is an armillary sphere and how does it differ from a celestial globe?

An armillary sphere is a skeletal framework of brass rings that represents the principal circles of the heavens, whereas a celestial globe is a solid sphere used to map constellations. The armillary sphere uses open rings to demonstrate the motion of stars and planets, while the celestial globe uses a solid surface. This device consists of a spherical framework of rings centered on Earth or the Sun that represent lines of celestial longitude and latitude.

Who invented the armillary sphere and when did the earliest development occur?

The Greek astronomer Hipparchus credited Eratosthenes as the inventor of the armillary sphere, with the earliest development in China going back to the astronomers Shi Shen and Gan De in the 4th century BC. The first permanently fixed equatorial ring of the armillary sphere was introduced by the astronomer Geng Shouchang in 52 BC. The sphere was totally complete in 125 AD with the help of the famous statesman, astronomer, and inventor Zhang Heng.

How did the armillary sphere function as a mechanical device in ancient China?

The world's first water-powered celestial globe was created by Zhang Heng, who operated his armillary sphere by use of an inflow clepsydra clock. In 723 AD, Yi Xing and government official Liang Ling-zan combined Zhang Heng's water powered celestial globe with an escapement device. This device featured drums hit every quarter-hour and bells rung automatically every full hour, functioning as a striking clock.

Why is the armillary sphere a national symbol of Portugal and Brazil?

In the end of the 15th century, the armillary sphere became the personal heraldic badge of the future King Manuel I of Portugal, when he was still a Prince. In 1815, when Brazil gained the status of kingdom united with that of Portugal, its coat of arms was formalized as a golden armillary sphere in a blue field. The celestial sphere of the present Flag of Brazil replaced the armillary sphere in 1889, yet the symbol remains a powerful representation of human attempts to map the cosmos.

What is the modern use of the armillary sphere in the United Kingdom?

An artwork-based model of an Armillary sphere has been used since the 1st of March 2014 to light the Paralympic heritage flame at Stoke Mandeville Stadium, United Kingdom. The sphere includes a wheelchair that the user can rotate to spark the flame as part of a ceremony to celebrate the past, present and future of the Paralympic Movement in the UK. The Armillary Sphere was created by artist Jon Bausor and will be used for future Heritage Flame events.

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