Glimpses of Another Astronomy

One of the most powerful recurring impressions, as we read further the Arabic nautical classics of the late 15th and early 16th century, is that they are mirrors or prisms through which we can half discern a very different way of approaching astronomy. It is as if Ibn Mājid and Sulaymān al-Mahrī are themselves manāzil, waystations, and also milestones on the transmission path from a remote and now barely discernible past, and as if they allow us glimpses into an altogether non-Western view and science of the heavens.

Speaking of one of the altitude measures taken in combination with the 23rd mansion, Ibn Mājid explains: “This measuring is reliable and well-known within the lore of substitutions (tabādul) and graduation (tadrīj) of the sky… no other is better known in reliability and usefulness.” These “substitutions“ refer to one of the aspects of the complex observational techniques whereby most points along the ecliptic, and pretty much everywhere through the heavens, are used in combination with other places, regardless of their brightness, because it is a fine-tuned web of relations, calibrated through centuries in a transnational decentralised endeavour.

In fact, and quite remarkably, whereas it seems that European celestial navigation started developing in earnest thanks to national state-sponsored action, the equivalent acquisition of knowledge took place from the Pacific to the Arabian Sea in an organic way, over many boundaries and centuries. This contrast has to do in part with the specific requirements of Mediterranean navigation, but it is nonetheless impressive to find, from Polynesia to Madagascar, from Guangzhou to Aden, such similar traditions of astronavigation, including stellar rhumbs and the use of the 27 or 28 lunar mansions.

In the case of Arab pilots, which we are studying, this astronomical lore was integrated in various degrees with a pre-existing, or perhaps rather overlapping, body of mythical knowledge which brought the stars in direct relation to everyday life in countless ways. Similar integrations can be observed in Indian and Far Eastern astronomical literature, as layer upon historical layer of celestial knowledge blended into an ever enriched tapestry. No small part of the reward in studying premodern nautical literature lies in realising how many different astronomies can be derived from the same stars—as if an archaic science haunts us, silently winking an eye at us from an immemorial past. [JA]