Ariana; history of Iranian, Iranic, Persian and Persianate civilization.
Medieval Persian Spherical GPS!
Hellenistic Greeks & Medieval Persians & Arabs also had a kind of GPS 
This Persian spherical astrolabe, crafted in 1480–81 in Iran and signed by the maker Mūsā, is an extraordinary scientific instrument and the only complete example of its kind surviving today.
Unlike traditional flat astrolabes, the spherical design allowed for highly precise astronomical calculations, tracking celestial bodies, determining prayer times, and aiding navigation by land or sea.
Made with exceptional craftsmanship, the astrolabe reflects the advanced mathematical and observational knowledge of late medieval Islamic scholars. Its intricate engraving and meticulous construction demonstrate both aesthetic refinement and scientific functionality, embodying the harmonious blend of art, astronomy, and engineering characteristic of Islamic scientific achievements.
Now preserved and displayed at the History of Science Museum in Oxford, this astrolabe offers modern audiences a tangible connection to 15th-century Iranian scholarship, highlighting the ingenuity and precision of one of the most sophisticated scientific traditions of the pre-modern world.
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An astrolabe (Ancient Greek: ἀστρολάβος astrolabes; Persian: اِستاره یاب Astaara yab) is an elaborate inclinometer, historically used by astronomers and navigators to measure the altitude above the horizon of a celestial body, day or night. It can be used to identify stars or planets, to determine local latitude given local time (and vice versa), to survey, or to triangulate. It was used in classical antiquity, the Islamic Golden Age, the European Middle Ages and the Age of Discovery for all these purposes.
Greek Astrolabe
About 550 AD the Christian philosopher John Philoponus wrote a treatise on the astrolabe in Greek, which is the earliest extant Greek treatise on the instrument.
Syriac Christian Astrolabe
In addition, Severus Sebokht, a bishop from Mesopotamia, also wrote a treatise on the astrolabe in Syriac in the mid-7th century. Severus Sebokht refers in the introduction of his treatise to the astrolabe as being made of brass, indicating that metal astrolabes were known in the Christian East well before they were developed in the Islamic world or the Latin West.
Islamic Astrolabes
Astrolabes were further developed in the medieval Islamic world, where Muslim astronomers introduced angular scales to the astrolabe, adding circles indicating azimuths on the horizon. The first person credited with building the astrolabe in the Islamic world is reportedly the 8th-century mathematician Muhammad al-Fazari. The mathematical background was established by the Muslim astronomer Albatenius in his treatise Kitab az-Zij (ca. 920 AD), which was translated into Latin by Plato Tiburtinus (De Motu Stellarum).
The earliest surviving dated astrolabe is dated AH 315 (927/8 AD). In the 10th century, al-Sufi first described over 1,000 different uses of an astrolabe, in areas as diverse as astronomy, astrology, horoscopes, navigation, surveying, timekeeping, prayer, sailing etc.
Islamic Spherical Astrolabe
The earliest description of the spherical astrolabe dates back to Al-Nayrizi (fl. 892–902).
Persian Linear Astrolabe
In the 12th century, the Persian scientist Sharaf al-Dīn Tūsī invented the linear astrolabe, sometimes called the "staff of al-Tusi". It was furnished with a plumb line and a double chord for making angular measurements and bore a perforated pointer".
Persian Geared Astrolabe
The geared mechanical astrolabe was invented by the Persian Scientist Abi Bakr of Isfahan in 1235.
Italian & Spanish Age of Discovery
It was versions and further evolutions of these instruments that helped later European sailors like Amerigo Vespucci cross the Atlantic and 'discover' the new world.
Link Below:
«اینجاست یار گمشده، گرد جهان مگرد
خود را بجوی سایه اگر جستوجو کنی»
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هوشنگ ابتهاج (هـ. الف. سایه)
