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The Great Contribution of Islamic Astronomers

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Bianca
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« Reply #90 on: October 13, 2008, 02:31:41 pm »








                                                                     G L O B E S





 
Armillary sphere



An armillary sphere had similar applications to a celestial globe.

No early Islamic armillary spheres survive, but several treatises on “the instrument with the rings” were written.

 







The spherical astrolabe was invented
by Islamic astronomers.



The spherical astrolabe was first produced in the Islamic world.

It was an Islamic variation of the astrolabe and the armillary sphere, of which only one complete instrument,
from the 14th century, has survived.







Terrestrial globe



The first terrestrial globe of the Old World was constructed in the Muslim world during the Middle Ages,

by Muslim geographers and astronomers working under the Abbasid caliph, Al-Ma'mun, in the 9th century.






Celestial globes



Celestial globes were used primarily for solving problems in celestial astronomy.

Today, 126 such instruments remain worldwide, the oldest from the 11th century. The altitude of the sun,
or the Right Ascension and Declination of stars could be calculated with these by inputting the location of
the observer on the meridian ring of the globe.

In the 12th century, Jabir ibn Aflah (Geber) was "the first to design a portable celestial sphere to measure
and explain the movements of celestial objects."






Seamless celestial globe



The seamless celestial globe invented by Muslim metallurgists and instrument-makers in Mughal India, specifically Lahore and Kashmir, is considered to be one of the most remarkable feats in metallurgy and engineering. All globes before and after this were seamed, and in the 20th century, it was believed by metallurgists to be technically impossible to create a metal globe without any seams.

It was in the 1980s, however, that Emilie Savage-Smith discovered several celestial globes without any
seams in Lahore and Kashmir.

The earliest was invented in Kashmir by the Muslim metallurgist Ali Kashmiri ibn Luqman in 998 AH (1589-90 CE) during Akbar the Great's reign; another was produced in 1070 AH (1659-60 CE) by Muhammad Salih Tahtawi with Arabic and Sanskrit inscriptions; and the last was produced in Lahore by a Hindu metallurgist Lala Balhumal Lahuri in 1842 during Jagatjit Singh Bahadur's reign. 21 such globes were produced, and these remain the only examples of seamless metal globes. These Mughal metallurgists developed the method of lost-wax casting in order to produce these globes.

These seamless celestial globes are considered to be an unsurpassed feat in metallurgy, hence some consider this achievement to be comparable to that of the Great Pyramid of Giza which was considered an unsurpassed feat in architecture until the 19th century.
« Last Edit: October 13, 2008, 02:39:45 pm by Bianca » Report Spam   Logged

Your mind understands what you have been taught; your heart what is true.
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