Science, Faith, and the Heavens: Astronomy in the Islamic World

This 16th-century illustration represents the celebration of the eid al-fitr, which marks the end of the fasting month, Ramadan. The religious practices of Muslims are regulated by the Hijrī calendar, a lunar calendar beginning with the migration of the prophet of Islam from Mecca to Medina in 622 AD. Since a lunar year is just 354 days long, constant calculations and observations are essential for determining important religious dates within Islam. Nowadays, Muslims combine traditional naked-eye observations of the crescent of the Moon, which signals the beginning and end of Ramadan, with nanosecond-precision level calculations made by astrophysicists.

This instrument is a qibla indicator from 19th-century Iran. The qibla is the direction to Mecca, which Muslims must face when performing their five daily prayers, wherever they are in the world. Finding the qibla requires an advanced knowledge of spherical trigonometry, but a qibla finder makes that operation easier. In this example, the lid contains a circular list of places with their respective qibla directions, called a gazetteer. After consulting the gazetteer, the desired direction could be found by using the instrument’s compass. Nowadays, Muslims use mobile apps that show a virtual compass and the direction to Mecca, in the manner of the old qibla indicators, but in digital format.

This celestial globe was likely made in Lahore (now in Pakistan) in the 17th century. It is formed by a hollow, seamless brass sphere on which figures representing 48 classical constellations are engraved, with more than a thousand stars marked by silver inlays. Celestial globes are instruments for observation, calculation, and demonstration that simulate the apparent motion of the sky, literally allowing their users to touch the stars. This example is also a remarkable combination of art and science. The constellation figures and other details denote the combined influence of Arab, Persian, and Indian culture in the Mughal empire, which extended from Central Asia through the Indian subcontinent between the 16th century and the 19th century.

The instrument shown here is an astrolabe made by Badr ibn ʿAbd Allāh in 1130-31 AD for Abū al-Qāsim Maḥmūd ibn Muḥammad ibn Malikshāh, the sultan of Iraqi Seljuks. Astrolabes are instruments for observation and calculation, and models of the Universe as it was understood in Antiquity and the Middle Ages. For that reason, they were referred to in the Islamic world as “Mirrors of the Universe”. Astrolabes were used for a variety of functions, including: to find the time of the day; to calculate the time of sunrise and sunset and the length of the day or night for a given date; to measure the height of buildings and other landmarks, or the depth of wells; and to carry out a variety of calculations. 

Fine astronomical instruments were valued not only by astronomers, but by all those who could afford them. As a consequence, astrolabes evolved into highly decorated pieces. One particular workshop based in Lahore, run by four generations of the same family during the 17th century, excelled in combining scientific rigor, artistry, and craftsmanship. The image shows a rete from an astrolabe made in 1601 by a member of that family, ʿIsā ibn Allāhdād. The rete is the celestial map in an astrolabe. The curved pointers protruding from the strapwork indicate the positions of selected stars in the sky. The inner, off-centered circle represents the apparent annual path of the sun in the celestial sphere. It was mainly in the rete that instrument makers showcased their technical and artistic skills.

Dr. Pouyan Rezvani is an Iranian postdoctoral researcher at the Bayerische Akademie der Wissenschaften in Munich, Germany, with a particular interest in the history of astronomical instruments in medieval Islam. Dr. Rezvani has analyzed and translated two previously unpublished astrolabe texts by the prominent astronomer Abū al-Rayḥān al-Bīrūnī (973 – c. 1050 AD), and in the course of research on unusual astrolabes, he carried out the first reconstruction of a crescent-shaped astrolabe made by Abū Saʿīd al-Sijzī in the 10th century AD. Dr. Rezvani was led into this field of study by “the collaboration of scholars with different languages, religions, and cultural backgrounds in the Islamic world, and their remarkable achievements in the history of science”. He says “studying the history of science shows how science connected different cultures to each other during centuries. Interestingly, even now ‘the history of science’ as an academic discipline brings together scholars from different countries.”

With a degree in physics and 30 years working in telecommunications research, Dr. Azucena Hernández decided to study art history and received a PhD in that field in 2017. Since then Dr. Hernández has been researching medieval scientific instruments at the University Complutense of Madrid, Spain. Dr. Hernández studied Arabic for three years, and is committed to highlighting  the achievements in science and technology written in Arabic in al-Andalus (the Muslim-ruled area of the Iberian Peninsula lasting from the 8th to the 15th century, that covered part of what is today Portugal and Spain). According to Dr. Hernández, this provides “a good case of a brilliant but mostly unknown contribution to the development of science and technology in my country, Spain. Medieval science written in Arabic has not had as much visibility as science written in Latin or other languages and now is the time to balance everything”.

Convin Splettsen divides his time between a degree in history, history and philosophy of science, and anthropology at Goethe-University in Frankfurt, and his activity as a magician and voice actor. He came across the astrolabe while attending a course on divinatory practices (such as astrology) in medieval Arabic and Latin texts, and was immediately struck by the allure of the instrument. Convin has since been exploring the connections between scientific instruments, history of science, and historical magic books. He believes that presenting these topics in an engaging way can help connect people: “in a globalized world it is important to know about each other’s history and culture. It will create an understanding for the other and the unknown, and might take away the fear of the unknown. Voice acting and magic have really helped me understand the importance of performing and presenting as a way of creating shared experiences and connecting people.”

Dr. Gaye Danışan is an Assistant Professor in the Department of the History of Science, Istanbul University, Turkey. Dr. Danışan studies the history of practical applications of astronomy in the Ottoman context, namely in navigation, astrometeorology (a discipline that sought to establish connections between celestial phenomena and the weather), calendars, and the production and use of portable astronomical instruments. “This allows me to examine different perspectives from Ottoman culture and social life”, says Dr. Danışan. “There are countless manuscripts and numerous astronomical instruments awaiting to be studied and examined in Turkey. I firmly believe that this research, and interdisciplinary studies in particular, will shed light on many unanswered questions about the history of science in the Ottoman space, and also cultural history in general.”

Our guest curator for this exhibition, Dr. Taha Yasin Arslan is a professor at Istanbul Medeniyet University, Turkey,  and a research fellow at Oxford University, England. Dr. Arslan’s research focuses on astronomical instruments in the Islamic world, particularly the instruments from Mamluk Egypt and Syria between the 13th and the 15th centuries, as well as their reception in 15th- and 16th-century Ottoman Turkey. As part of his work, Dr. Arslan makes accurate replicas of original instruments, and hopes to eventually replicate the spherical astrolabe he is holding in the photo, which is his favorite instrument. As a lifelong astronomy enthusiast, and after studying Islamic philosophy, Dr. Arslan embarked on a journey at once intellectual and hands-on to better understand the deep connections between philosophy, culture, religion, and science and its instruments in the Islamic world. He is especially interested in how science was nurtured by Islam, conferring a dimension of accuracy on its religious practices. Dr. Arslan considers that these studies help “rethink the history of science, allowing us to revamp our perspective on modern science.”