Archaeologists have discovered a rare Islamic astronomical device from the 11th century bearing Arabic and Hebrew signs, one of the earliest examples of such an instrument found.
The researchers called it a “powerful record” of hundreds of years of scientific exchange between Arabs, Jews and Christians, likening it to a “pocket computer”.
The device was spotted in a museum in Verona, Italy, by Federica Gigante of Cambridge University’s School of History, who said it is now “the single most important object in their collection”.
Astrolabes were the world’s first pocket computers, providing a portable two-dimensional model of the universe that fit in the user’s hand, allowing them to calculate time and distances, as well as plot the positions of stars.
“When I visited the museum and examined the astrolabe closely, I realized that not only was it covered with beautifully carved Arabic inscriptions, but I could also see faint Hebrew inscriptions. I could only make them out in the sharp light coming through the window. I thought I might be dreaming, but I kept seeing more and more. It was very exciting,” Dr. Gigante said.
By analyzing its scientific, design, construction and calligraphic features, Dr. Gigante dated and located the creation of the “Verona astrolabe”. From the engraving style, he found that the device is Andalusian. The layout of the scales corresponded to instruments made in Andalusia, the Muslim-ruled region of 11th century Spain.
Based on the inscriptions found on the instrument, it is suspected that it may have been made in Toledo, a city that was a center of coexistence and cultural exchange between Muslims, Jews and Christians.
The astrolabe also contains Muslim prayer verses and prayer names, possibly indicating that its original users took time out for their daily prayers.
It also appeared that Hebrew lines were added in the translations, suggesting that the object had left Spain or North Africa and was circulating among the Jewish diaspora in Italy, where Arabic was not understood and Hebrew was used instead.
There were also Hebrew translations of the Arabic names of the astrological signs of Scorpio, Sagittarius, Capricorn, Aquarius, Pisces and Aries.
The Verona astrolabe has a perforated disk representing a celestial chart, one of the oldest known astrolabes. It also bears similarities to the only surviving Byzantine astrolabe, made in 1062 AD, as well as to the oldest European astrolabes made in Spain according to the Islamic model.
When the device was analyzed in more detail, the rough timing and position of the sky at the time the astrolabe was created could be plotted. By doing so, the researchers calculated that the disks were placed in a position to make the calculations that the stars had in the late 11th century.