Rabbis on the Moon
It’s not science fiction -it’s real life. Three rabbis in particular have moon craters named after them, and some other rabbis who made advances in the field of astronomy may have their names up there some day too. Join Rabbi David Sedley as explores their stories and how they got there.
Rabbis on the Moon: Let there be luminaries – Introduction
Rabbis on the Moon: Mashallah ibn Athari
In this class, we learn about Mashallah ibn Athari, one of the most influential and important astronomers and astrologers of the ninth century.
Chaucer used Mashallah’s work for his Treatise on the Astrolabe. Abraham ibn Ezra translated one of his books to Hebrew. And Mashallah helped work out the most auspicious date to found the city of Baghdad.
Rabbis on the Moon: Levi ben Gershom, Ralbag (Gersonides)
Ralbag is credited with inventing Jacob’s Staff, a tool for measuring the relative positions of stars.
His commentary on the Torah was included in early editions of Mikraot Gedolot but his theology was criticized by several later rabbis.
His fundamental view is that the Torah must conform to reality as we perceive it.
Rabbis on the Moon: Rabbi Avraham Zacuto
Rabbi Avraham Zacuto came from a family that had been exiled from France and moved to Castile. He learned both Torah and science in Salamanca, his home town, and became a teacher of astronomy. He was close to the local bishop, to whom his influential astronomical work “Hahibur Hagadol” was dedicated.
In 1492, Zacuto, along with all the Jews of Spain, were forced to leave the country. Zacuto, his teacher Rabbi Yitzchak Abuhav (author of Menorat Hamaor), and his family moved to Portugal. In Portugal, Zacuto was appointed as royal astronomer by King John II. After John’s death, his grandson, Manuel I also respected Zacuto. However, in 1496, Manuel expelled or forcibly converted all the Jews in Portugal. Zacuto fled to Tunisia, where he wrote his history of the Jewish people, Sefer Yuhasin. After this, information about Zacuto becomes scarce, but it seemed that he ended his days in Jerusalem in 1515 (though he may have died in Syria in 1520).
The crater Zagut on the moon is named for Avraham Zacuto.
Rabbis on the Moon: Rabbi David Gans
Rabbi David Gans was a pupil of Copernicus. Probably the first rabbi to look through a telescope and the first to acknowledge the truth of the Copernican universe. His books include Magen David and Nehman Venaim.
He was also a historian, writing a book entitled Tzemach David.
Rabbi David Sedley lives in Jerusalem with his wife and six children. He was born and raised in New Zealand before making Aliya in 1992. He left Israel temporarily (for eight years) to serve as a communal Rabbi in Scotland and England and returned to Israel in 2004. He has translated Rabbeinu Yonah's commentary on Pirkei Avos and is the co-author of Sefiros: Spiritual Refinement Through Counting the Omer (both Judaica Press). Over the years Rabbi Sedley has worked as a journalist, a translator, a video director and in online reputation management. He also writes a weekly Torah blog on the Times of Israel.