(Photograph) - In his traditional December address to Rome's students in St Peter's Square, the Pope spoke of the limits on temporal knowledge. 'Only God, with his omnipotence, controls the universe. In the past century, powers that wanted to impose their domination have shown themselves to be fragile. Even science, technology and culture, when they show a desire for omnipotence, are in the end revealed as grass that quickly dries, as a flower that wilts and dies,' he said. Photograph by AP