### Conveners

#### Early modern Astronomy: Cosmological Models from Kepler to Boscovich: Part 1

- Pasquale Tucci (retired, Università degli Studi di Milano)

#### Early modern Astronomy: Cosmological Models from Kepler to Boscovich: Part 2

- Ivana Gambaro (DAFIST - Università Genova)

Questa relazione prenderà in esame le tesi fisico-cosmologiche del De stella nova (1606) di Kepler nel contesto delle discussioni sulla natura delle 'novità celesti’ (comete e nuove stelle) e sui loro moti. Al centro dell’attenzione sarà la discussione critica di alcune tesi sulla natura fisica e i moti della nova che lasciavano aperta la possibilità che l’universo fosse infinito. La risposta...

In the last edition of his *Commentarius in sphaeram Ioannis de Sacrobosco*, published in 1611, Christoph Clavius urged astronomers to work out an astronomical solution that integrated the ground-breaking Galilean novelties of 1610. As the Collegio Romano mathematics professor stated, « since this is so, astronomers ought to see how the celestial orbs may be arranged in order to save the...

The controversy between the Jesuit Giovanni Battista Riccioli and the Galileans, Giovanni Alfonso Borelli and Stefano degli Angeli is part of the broader question of the opposition to the Copernican system on the part of Catholic orthodoxy. However, it had a fundamental role in highlighting an unresolved crucial question of Galilean dynamics: the "true" or "absolute" motion of falling bodies...

« It is a grave error to believe that our mental representations of the truth are unique as if several different images could not be exhibited of a single statue » (F. Lana Terzi, 1684). This eclectic epistemology was shared by several Jesuit confrères in the second half of the 17th century. I will discuss the case of Riccioli and that of Kircher. With the exception of his beloved proof of...

In his *Histoire de l’astronomie moderne* (II, 1785, p. 211), J. Bailly argued that Riccioli had not understood Kepler's laws. This has been questioned (J.L. Russell, 1964) and deserves consideration. Riccioli played an important role in the comprehension and dissemination of Kepler’s works, at least in the Italian context. Riccioli seriously discussed Kepler's ideas in his *Almagestum Novum*...

**The History on the Moon**

Over the time, the lunar nomenclature presented by Giambattista Riccioli (1598-1671) in his

*Almagestum novum*, in the mid-seventeenth century, outperformed contemporary proposals, such as that developed by Michael Florent van Langren (1600-1675) or the even more famous

*Selenographia*by Johannes Hevelius (1611-1687). His idea of associating the various lunar...

Johannes Kepler compiled the *Epitome Astronomiae Copernicanae* (*Summary of Copernican Astronomy*) in the years of his maturity. He had already developed his three astronomical laws, and he had understood how the adoption of a new astronomy, founded upon the Copernican point of view, compelled the astronomers to also introduce a new physics. Kepler's celestial physics permeates this...

The fundamental elements of Kepler’s dynamics will be explained. They were offered by Kepler in Astronomia Nova and Epitomae Astronomiae Copernicanae. Afterwards, I will analyse the connections among such elements and the first two Kepler laws. For, an interesting conceptual and historiographic problem exists: is it possible that a “wrong” dynamics is the basis of a “correct” kinematics? Or,...

The problem of comet orbit determination has been one of the most important challenges in early modern astronomy since Newton’s Principia at least, but came to an apex in the mid-eighteenth century, when many comets were being observed and a plurality of methods for calculating their paths with increasing precision emerged. The present paper studies Ruggiero Boscovich’s contribution to this...