Never has an astrolabe provided so much information as the one discovered in Verona (Italy) and which reveals a complex history of scientific exchange between Arabs and Jews. Despite what is currently happening in Israel and Gaza, collaboration between Islam and the Hebrew world has been fruitful for centuries.
This 11th century Islamic astronomical instrument contains inscriptions in both Arabic and Hebrew, making it one of the few examples known in the world. The disc was adapted, translated and corrected for centuries by Muslim, Jewish and Christian users in Spain, North Africa and Italy.
According to Dr. Federica Gigante, from the University of Cambridge, in an article published in the magazine Nuncius, a newly uploaded image of the astrolabe was found by chance on the website of the Fondazione Museo Miniscalchi-Erizzo. When she asked them, "the museum didn't know what it was," she explains.
"Now, however, it is the most important object in his collection. When I visited the museum and studied the instrument closely, I noticed that not only was it covered with beautiful engravings in Arabic, but I could see faint inscriptions in Hebrew. I was only able to distinguish them thanks light coming through a window. I thought I might be dreaming but I kept seeing more and more. It was very exciting," he says.
For Gigante, the disk used to determine the latitude, longitude, height or position of celestial bodies, in addition to calculating time “is not only an incredibly rare object, but a powerful record of scientific exchange between Arabs, Jews and Christians for hundreds of years.”
“The Verona astrolabe underwent many modifications, additions and adaptations as it changed hands. “At least three different users felt the need to add translations and corrections to this object, two in Hebrew and one in a Western language,” adds the researcher.
Astrolabes were the world's first smartphone, a kind of laptop that could have hundreds of uses. They provided a portable two-dimensional model of the universe that fit in the hand of its users, allowing them to calculate time, distances, plot the position of the stars and even forecast the future by creating a horoscope.
Dr. Federica Gigante, an expert in Islamic scientific instruments, dated and located the creation of the "Verona astrolabe" by analyzing its design features, construction and key calligraphy. She identified that the object was Andalusian and, from the style of the engraving and the arrangement of the scales on the back, she compared it to instruments made in Al-Andalus in the 11th century.
On one side of a plaque is inscribed in Arabic “for the latitude of Córdoba, 38° 30'”, while on the other side “for the latitude of Toledo, 40°”. Gigante suggests that the astrolabe could have been manufactured in Toledo at a time when it was a thriving center of coexistence and cultural exchange between Muslims, Jews and Christians.
The disk features Muslim prayer lines and prayer names, organized to ensure that its original users had time under control to perform their daily prayers. A signature inscribed on the astrolabe reads "for Isḥāq [...] the work of Yūnus." This was recorded some time after it was built, probably by a later owner.
Isḥāq and Yūnus could be Jewish names written in Arabic, a detail that suggests that the object was at one point circulating within a Sephardic Jewish community in Spain, where Arabic was the common spoken language. A second added plate has inscriptions for typical North African latitudes, indicating that at another time it was perhaps used in Morocco or Egypt.
Additionally, more than one person added Hebrew inscriptions to the astrolabe. One set of additions are deeply and carefully carved, while a different group of translations are very light, uneven, and show an unsteady hand. "These texts in Hebrew indicate that the object left Spain or North Africa and circulated through Italy among the Jewish diaspora community, where Arabic was not understood and Hebrew was used instead," says Gigante.
Unusually, one of the Hebrew additions, clearly engraved above the Arabic mark for latitude 35°, reads “34 and a half” instead of “34 ½,” suggesting that the engraver was neither an astronomer nor an astrolabe maker. . Other Hebrew inscriptions are translations of Arabic names of the astrological signs: Scorpio, Sagittarius, Capricorn, Aquarius, Pisces and Aries.
Federica Gigante assures that these translations reflect the recommendations prescribed by the Spanish Jewish scholar Abraham Ibn Ezra (1089-1167) in the oldest surviving treatise on the astrolabe in the Hebrew language, written in 1146 in Verona, exactly where the astrolabe is located today. astrological instrument.
12th century Verona was home to one of the oldest and most important Jewish communities in Italy. Ibn Ezra's treatise assumes pre-existing knowledge of the astrolabe among this Jewish community, demonstrating that the disk must have already been popular.
The astrolabe also features corrections inscribed not only in Hebrew but also in Western numerals, the same ones we use today. All sides of the plates feature lightly scratched figures, which translate and correct latitude values, some even several times.
Dr. Gigante believes that it is very likely that these additions were made in Verona for Latin or Italian speakers. In one case, someone lightly scratched the numbers “42” and “40” near the inscription that read “for the latitude of Medinaceli, 41° 30'.”
The researcher understands that both numbers “not only differ from the value given in Arabic, but they do not agree with each other. It may be that a later owner thought the original Arabic value was incorrect and modified it. But the correct value for the latitude of Medinaceli is 41°15', which indicates that the Arabic data was more accurate than any of the amendments. Elsewhere, Gigante found more erroneous rectifications related to the latitudes of Córdoba and Toledo.
The astrolabe features a "rete", a perforated disc that represents a map of the sky, which is one of the first known to have been manufactured in Spain. Surprisingly, it presents similarities with the network of the only surviving Byzantine disk manufactured in the year 1062, as well as with those of the first European astronomical instruments, manufactured in Spain following the Islamic model.
The astrolabe probably found its way into the collection of the Veronese nobleman Ludovico Moscardo (1611-1681) before passing to the Miniscalchis. In 1990, the family founded the Fondazione Museo Miniscalchi-Erizzo to preserve its collections. "This object is Islamic, Jewish and European, they cannot be separated," concludes Dr. Gigante.
