Astrolabe

Perhaps more than ever our human experience feels like a bleak combination of uncertainty and doubt. Or maybe that’s how the year has fared for many, with instability topping the charts! And it is in those strange moments we find ourselves resorting to the familiar, something secure. Like going back to a favorite book or visiting an old friend. On a similar note, I find myself returning to objects from the past. What better way to realize the permanence of something?

In this much-delayed edition, I am featuring an Astrolabe. It is an extraordinary device purposed for discoveries, far from anything abstract or uncertain. To think of an object from the Middle Ages that continued to guide astronomers and surveyors from the Roman to the Arab world deserves a read.?

Though its inventor(s) remain uncertain, what is known is that the earliest mentions of an astrolabe date back to the Greeks, most notably in the 2nd-century mathematician, astronomer and geographer, Ptolemy’s Planisphaerium (Celestial Plane). In the centuries to follow, Arab scholars further developed and improved the instrument; Al-Farghani’s landmark treatise on the astrolabe titled Al-Kitab al-Kamil fi Sana’at al-Asturlab al-Shimali wa-l-Janubi wa–'Ilaliha bi-l-Handasa wal-Hisab (The Complete Book on the Construction of Northern and Southern Astrolabes and their underlying principles by Geometry and Calculation), written in the 9th century, became a widely distributed manual detailing the mathematics fundamental to the device's use and construction. By the 13th century, the knowledge spread through translations far across Europe for terrestrial and astronomical observations. By the turn of the 18th century, astrolabes were replaced by more sophisticated instruments called quadrants.

Understanding the theory of how an astrolabe works gets complicated without familiarity with its physical components. The image below is of an 18th-century brass astrolabe in the Sharjah Museum of Islamic Civilization that I visited in the summer. Its expansive display encourages a closer study of its various parts: in the centre is the main body or the mater. This astrolabe is accompanied by five plates called climates. Each climate is engraved with a complex network of latitudes (Equator, Tropics of Cancer/Capricorn…); it represents the projection of the local sky from the horizon. The fretted plate on the right is the rete and represents the projection of the celestial sphere and pointers of the main stars.

The climates sit inside the mater aligned with the rete on top. Then as per the observer’s interest, the rete is rotated to record various data, from the position of stars to finding the time or direction of Mecca.

The blue stones on the mater’s circumference are fitted on the limb inscribed with the hours and degrees. The instrument, which in the medieval period was mainly made of heavy brass, is held by a ring attached to the throne, usually decorated with elaborate designs.?

Not to be forgotten is the back of an astrolabe that is fitted with the alidade. It is a ruler that helps the observer read other scales of important information as well as the altitude of a celestial body and position of the sun in the zodiac. In the following illustration, the yellow colour emphasizes this rotatable part.

Essentially, consider the astrolabe as a mega calculator. To locate the position of the sun, moon, other planets, or major objects in the sky. Also, the latitude of stars or the altitude of objects, say a mountain or a tower. Depending on the earth's rotation, this handheld multi-tool also presented the location of places and time of day, which is especially useful for ascertaining prayer times for Christians and Muslims.

For those who made it this far, here's a visual treat. A video demonstrating the assembly of an astrolabe in the collection of the Louvre Abu Dhabi. On display in the Children's Museum, this astrolabe indicates Moorish influences and is composed of a mater, four climates, a rete, and an alidade. It is remarkable how this astrolabe reminds us of various versions of astrolabes that would have been commissioned to serve very different regional and cultural contexts.?

A special thanks to Zahra Faridany-Akhavan, PhD who helped identify the inscription within the concentric circles of the mater from the Sharjah Museum that interestingly bear the names of cities in India: Benares, Udaipur, Kashmir, Allahabad, Rampur, Delhi, Rajpur; Ajmer, Udaipur, Moradabad…; along with other countries: Mongolia, Yunan (Greece), Misr, Suriyah, Sinan, Iran, Espagne, Anakara...; months in the Islamic calendar: Jamadil Awal, Jamadil Sani, Shaban, Rajab, Safar, Ramadan…, and Muslim prayer timings: Zohar, Asr.?

I am ending this note with a miniature painting of Mughal Emperor Humayun depicted kneeling and reading. Note the representation of an astrolabe in the foreground (right), symbolising the emperor’s deep interest in astrology.?

P.S.: To all who supported my newsletter these past few months? artists, designers, and museums, I am grateful for trusting me to share your stories. I look forward to presenting more beautiful things in the new year.?

Happy New Year. May we all reach for the stars!