Today is Copernicus Day, celebrating the birth of Nicolas Copernicus. He is rated as "the father of modern astronomy"; and he was the first person to present a scientific basis for the Sun being at the center of the universe rather than the Earth. Jewish reactions to Copernicus range from hostile rejection to ambivalence to warm reception. Those who rejected his model did so for a variety of reasons. Some of these objections were of little merit from a religious perspective. But others presented more powerful objections. Rabbi Pinchas Eliyahu Hurwitz of Vilna (d. 1821) authored a popular work on science entitled