easily and economically moved; whether the center of the universe was a more or less noble position; and many others. Many of the anti-Copernican arguments in the New Almagest had roots in the anti-Copernican arguments of Tycho Brahe. Riccioli argued vigorously against the Copernican system, and even characterized certain arguments for terrestrial immobility as unanswerable, but he also rebutted some anti-Copernican arguments, invoking counterarguments from the Copernicans. For example, he presents the common opinion that, if the Earth rotated, we ought to feel it, and since we do not, the Earth must be immobile. But he then says that mathematically there is no necessity for such a sensation. He likewise dismisses the ideas that buildings might be ruined or birds left behind by Earth's motion—all may simply share the eastward rotational motion of Earth, like the east-facing cannon and ball discussed above. Perhaps for this reason Riccioli has at times been portrayed as a secret Copernican—someone whose position as a Jesuit necessitated opposition to the Copernican theory. The Astronomia Reformata (Reformed Astronomy) Another prominent astronomical publication of Riccioli's was his 1665 Astronomia Reformata (Reformed Astronomy)—another large volume, although only half the length of the New Almagest. The contents of the two significantly overlap; the Reformed Astronomy might be thought of as a condensed and updated version of the New Almagest. The Reformed Astronomy contains an extensive report on the changing appearance of Saturn. Included in the section on Jupiter is an apparent record of a very early (if not the earliest) observation of Jupiter's Great Red Spot, made by Leander Bandtius, Abbot of Dunisburgh and owner of a particularly fine telescope, in late 1632. Also in that section Riccioli includes reports of Jovian cloud belts appearing and disappearing over time. The appearance of the physico-mathematical argument in the Reformed Astronomy was the occasion for Stefano degli Angeli (1623–1697) to launch an "unexpected, somewhat disrespectful and sometimes flippant attack" on Riccioli and the argument. James Gregory published a report in England in 1668 on the resulting public and personal dispute on the matter of falling objects. This was a prelude to Robert Hooke's (1635–1703) invitation to Isaac Newton (1642–1727) to resume his scientific correspondence with the Royal Society, and to their ensuing discussion about the trajectory of falling bodies "that turned Newton's mind away from 'other business' and back to the study of terrestrial and celestial mechanics." The Reformed Astronomy featured