It is a nice summer’s day; the sun is shining in the Sicilian sky. On Mount Antennamare, which looks out over the strait and the city of Messina, the perfume of oregano permeates the calm air. A Lambretta’s buzz gets closer, as it emerges from around a corner. Two young men are riding it; one is driving, and the other looks distracted and is wearing a Basque beret. They talk, joke, leave the Lambretta, and proceed on foot. They discuss chess matches, they joke about the differences between “Sicilians” and “Continentals,” they talk about the Don Mommo restaurant where you can eat for two liras, they contemplate Sicily’s perfumed oregano and maybe also the visionary project to span the Messina Strait with a bridge. At one point, the young man with the beret has a nervous tic, twitches suddenly, and begins talking about soap bubbles. Soap bubbles. They a favorite childhood pastime; everyone knows how to make one, with a plastic jagged-edged ring and some water mixed with detergent. For a child, soap bubbles are a question of instinct and practice, of the skill in knowing how much and how hard to blow, but for a mathematician they are a phenomenally complex topic. Ennio De Giorgi, wearing his beret, explains all of this to Ferruccio De Stefano, the friend who is driving the Lambretta.