Galileo’s Dialogue Concerning the Two Chief World Systems is published in Florence.

It Happened on
September 22, 1632

"Dialogue Concerning the Two Chief World Systems," was written in the form of a dialogue between three characters: Salviati, Sagredo, and Simplicio. While Galileo used this format to present different viewpoints on the heliocentric model of the solar system, with Salviati advocating for Copernicanism and Simplicio representing the geocentric view, the choice of names held deeper significance. Simplicio's character, who often defended the traditional Earth-centered cosmology, was seen by some as a thinly veiled caricature of Pope Urban VIII, who had initially supported Galileo's work. This subtle criticism and the confrontational style of the book likely contributed to Galileo's subsequent trial and condemnation by the Catholic Church for heresy, making "Dialogue" a pivotal episode in the history of the conflict between science and religion.