"In this regard," the pope said, "it may be that not everyone knows that St. Peter's Square is also a meridian: the obelisk, in fact, casts its shadow along a line that runs along the pavement toward the fountain under this window, and in these days the shadow is at its longest of the year. This reminds us of the function of astronomy in marking out the rhythm of prayer. The Angelus, for example, is recited in the morning, at noon, and in the evening, and with the meridian, which was used in ancient times to identify 'true noon', clocks were adjusted."

The memory of Galileo Galilei brings to the surface many controversies over the supposed enmity between the Church and science. In reality, the pope specified, "my predecessors of venerable memory included devotees of this science, like Sylvester II, who taught it, Gregory XIII, to whom we owe our calendar, and St. Pius X, who knew how to make sundials." There is therefore a friendship between faith and science, astronomy and faith.