Years have gone by, and though Galileo hasn’t written anything further on the subject of Copernicus, he has amassed a group of pupils in the form of Federzoni, Andrea, and the Little Monk. The group is meeting when a former student enters. The student wishes to explain to Galileo why he recently attacked Copernicus in his book. Galileo tells the student that there’s no need: he’s perfectly in line with the Church’s teachings. Galileo pulls his proving stone from his pocket, drops it to the ground, and tells the student that he is “quite within his rights” to say that the stone has just flown to the ceiling.
Weirdly, while Brecht works to associate Galileo’s spreading of forbidden knowledge with the devil, Galileo also parallels another biblical character: Jesus. The way that Galileo amasses followers is reminiscent of the way that Jesus gained disciples. Later in the text, Galileo’s “disciple” Andrea will go out to spread Galileo’s message in much the same way that Jesus’ disciple Paul did in forming the Catholic Church.
Meanwhile, Virginia and Mrs. Sarti discuss Virginia’s engagement to Ludovico. Sarti feels that Virginia is taking their upcoming marriage too lightly and advises the girl not to let her father be a part of the ceremony. She also suggests that Virginia have her horoscope read by a “proper astronomer” at the University. Virginia replies that she already has. Their conversation is interrupted by the rector of Galileo’s college, who has come to drop off a book. He refuses to interrupt Galileo, however, as any minute taken away from Italy’s greatest man is a moment wasted.
Mrs. Sarti’s sudden reappearance is something of a quirk here. Readers could be forgiven for thinking that she died during the plague, as it’s suggested that she did and she’s long been absent. Mrs. Sarti’s suggestion that Virginia see a “proper astronomer” (when Virginia’s father is the most famous astronomer in the world) to have her horoscope read serves as a bit of lighthearted humor.
The book is delivered to Federzoni, who can’t read the title, as it’s in Latin. Andrea reads it for him (it’s a book about sunspots that doesn’t interest any of them). The inscription reads “To the greatest living authority on physics, Galileo Galilei.” The group discusses what sunspots might be, though Galileo remains silent throughout.
Brecht seems to keep Federzoni around as a reminder of Galileo’s championing of the common man and distaste for Latinate texts. Brecht needs this foil, since Andrea has grown up to be a well-educated scientist, who can read Latin.
Andrea brings them back to their work at hand, using an experiment to test Aristotle’s hypothesis that a broad flat piece of ice will float on water whereas an iron needle will sink. The Little Monk begins to present Aristotle’s argument in Latin, but Galileo demands that he translate it into Italian for Federzoni’s sake. Through the experiment, they discover that Aristotle was again wrong, and Federzoni laughs at the fact that the Church seemingly never bothered to test anything he said. The others laugh with him.
The experiment is presented in a way that’s much easier to understand than some of the earlier conversations about celestial motion. Yet, at its heart, the experiment Galileo undertakes is almost the same as his work with the moons of Jupiter. Before, Galileo sought to prove that Copernicus was right and Aristotle wrong. Now, forbidden to side with Copernicus, he simply seeks to prove Aristotle wrong.
Ludovico arrives with news that the current Pope is dying. His suspected replacement is none other than Barberini. Convinced that Barberini will usher in a new age of reason for the Church, Galileo renews his research into the Earth orbiting the Sun.
Galileo’s resumption of his old work is comically quick, with no change in set or props indicated. It’s as though he had kept his old work waiting by his side all along.
Ludovico, however, is not as happy. Ludovico reminds Galileo that he signed a declaration saying he would never again promote Copernicus’ ideas. Furthermore, Ludovico is distressed because his family is very well-respected and rich; his wife (Virginia) will have to sit by him in Church. Ludovico worries that his family will lose status if Galileo again takes up this research. Galileo is undeterred, and Ludovico resorts to threatening him. He says that his family—and others like them—will have considerable leverage with the new Pope, regardless of the Pope’s love for science. Above all, the Pope must avoid the peasants questioning the established order of things, or they may begin to question him.
Ludovico’s speech mimics that of the Procurator much earlier. Yet again, Galileo is expected to balance pedestrian concerns (like someone’s reputation) with his great work uncovering the secrets of the universe. Galileo has already proven that he cares about eating, and will prove shortly that he has no desire to be persecuted, but preserving the reputation of others proves yet again to be of no concern to him. Certainly, he doesn’t feel the threat Ludovico levels against him in the slightest.
Federzoni replies that this surely won’t be a problem, since the peasants can’t read the Latin in which Galileo will publish his findings. Galileo, however, says that he plans on publishing in simple Italian, since his findings should be available to those who work with their hands and know how things work. At this, Ludovico leaves, asking that someone else explain their breakup to Virginia. When Virginia finds out, she faints, and the others run to her. Galileo, however, remains locked in his research, saying that he simply has to know the truth of things.
Galileo hasn’t mentioned his plan to publish in Italian up until this point. While it seems to surprise Federzoni and Ludovico, readers (with their privileged viewpoints from the outside looking in) have likely anticipated this decision. Galileo knows his knowledge will spread, and he wants to make sure it spreads as widely and easily as possible.