Nicolaus Copernicus Prussia also resisted the Polish crown's efforts for greater control over the region. "Encyclopædia Britannica", "Encyclopedia Americana", "The Concise Columbia Encyclopedia", "The Oxford World Encyclopedia", and "World Book Encyclopedia" refer to Copernicus as a "Polish astronomer". Sheila Rabin, writing in the "Stanford Encyclopedia of Philosophy", describes Copernicus as a "child of a German family [who] was a subject of the Polish crown", while Manfred Weissenbacher writes that Copernicus's father was a Germanized Pole. There are additional arguments for Kopernik's Polish descent on his father's side. Kopernik's Y-DNA haplogroup, R1b L51, is found in southern Poland (in Silesia, where his father
Nicolaus Copernicus in law only after seven years, following a second return to Italy in 1503) than to studying the humanities—probably attending lectures by Filippo Beroaldo, Antonio Urceo, called Codro, Giovanni Garzoni, and Alessandro Achillini—and to studying astronomy. He met the famous astronomer Domenico Maria Novara da Ferrara and became his disciple and assistant. Copernicus was developing new ideas inspired by reading the "Epitome of the Almagest" ("Epitome in Almagestum Ptolemei") by George von Peuerbach and Johannes Regiomontanus (Venice, 1496). He verified its observations about certain peculiarities in Ptolemy's theory of the Moon's motion, by conducting on 9 March 1497 at Bologna