What was the role of the astrolabe in Jewish culture? It was as important as the role it played in Muslim and Christian cultures: the astrolabe was the most symbolic of medieval astronomical instruments and embodied the best astronomical knowledge then available. It was associated with power and luxury in the Muslim and Christian courts, where astrologers (frequently Jews) used it to forecast the future of the king and his kingdom.
Astrolabes were occasionally treated like jewels, and as such, they were embellished with precious stones and displayed in public. They were (and still are) collectible items that indicated on the metal of the mater the names of the patron and the maker. Very few astrolabes with Hebrew script are extant; they are characteristically restrained in their decoration, which makes the Hebrew script especially noticeable.
There is sufficient (instrumental and textual) evidence that Jews were involved in the diffusion of the astrolabe through texts and instruments. Some of them, like Levi ben Gerson (13th c.), introduced improvements and modifications in the standard planispheric astrolabe. Others, like Abraham ibn Ezra, found in the biblical text indications of its knowledge among the Israelites before its invention by Greeks.
Research about the astrolabe in Jewish culture and the degree of involvement of Jews in astrolabe making and astrolabe diffusion is still lacking in the fields of Jewish studies and of the history of science. Researchers should pay attention to the fact that astrolabes in Jewish culture employed many languages (Hebrew, Catalan, Judaeo-Arabic, Arabic, and Castilian) and were used in very different contexts, which was a reflection of the complexity and diversity of Jewish culture in the Middle Ages.
The Hebrew astrolabes displayed at the British Museum in London and at the Adler Planetarium in Chicago are interdisciplinary artefacts made in the interplay of medieval science (astronomy), medieval practice (astrology), and medieval philosophy (cosmology). They took their form and were preserved and modified in the context of an ensemble of knowledge whose texts and instruments travelled much more than usually assumed and whose writers, readers, and makers were less homogeneous than previously believed. All of this indisputably makes the astrolabe a fascinating artefact and an illuminating object about Jewish culture in the Middle Ages.