ר׳ דוד בן שלמה גנז

ר׳ דוד בן שלמה גנז (1541–1613), known by his chronicle צמח דוד, was a pioneering Jewish historian, mathematician and astronomer of Renaissance Prague. Born in Lippstadt, Westphalia, he studied in Bonn and Frankfurt before joining the Kraków academy of ר׳ משה איסרליש. In 1564 he moved to Prague, where he learned from ר׳ סיני בן בצלאל and the מהר״ל. A period in Nordheim introduced him to Euclidean mathematics. Back in Prague he engaged both Jewish learning and the new astronomy of the Rudolfine court, working in the intellectual orbit of Tycho Brahe and Johannes Kepler. צמח דוד, first printed in Prague in 1592, combines Jewish chronology with a separate history of the nations and became a landmark of early modern Hebrew historiography. His astronomical work מגן דוד was announced in 1612; its fuller text appeared posthumously as נחמד ונעים. Gans treated mathematics and astronomy as legitimate branches of divine wisdom and helped translate contemporary scientific knowledge into Hebrew. He died in Prague in 1613 and was buried in the Old Jewish Cemetery, where his tombstone bears a goose—an emblematic play on the German word Gans .