Gans, David ben Solomon, Nechmad ve-naim.
Jessnitz; Prague, [Israel ben Abraham], 1743.
The study of astronomy is important not only for the Jewish calendar but as proof for the cultural achievements of the Jewish people.
David Gans was born into a prosperous merchant family in Westphalia. As a youth he studied with Moses Isserles, the renowned head of the Kraków yeshiva. Gans moved to Prague in 1564, where he continued his studies with Sinai ben Betsal’el, the brother of Maharal of Prague.
This is David Gans’ main astronomical and geographical work and also the first account of Copernicus’ heliocentric system in Hebrew. Ganz was associated with the famous astronomers of his generation. He also studied rabbinics and kabbalah with Reuben Fulda in Bonn; Eliezer Treves in Frankfort; Moses Isserles in Cracow; and Judah Loew (the Maharal) in Prague. He devoted himself to the study of mathematics and astronomy at the encouragement of Isserles.
Nechmad veNaim consists of studies in mathematics, astronomy and geography but rejects astrology as antithetical with the Jewish tradition. One of its more important features is the discussion of the Jewish influence on non-Jewish astronomy. According to Gans, Adam passed on his universal knowledge of astronomy to Abraham who then passed it onto his sons from whom the ancient Egyptians must have learned it.