The end of the Middle Ages was probably the point in time when people were the most pious and God-fearing, the most dogged by evil and tormented by devils, demons and nightmares. Fear and worry dominated earthly life, plagues and disasters were seen as portents for the imminent end of the world, a certain fate that seemed to have arrived in 1520, when the Turks led by Suleiman the Magnificent laid siege to Vienna. Yet, the Renaissance was a time when commerce, the arts and science were flourishing. Inventors, explorers and conquerors created a new perspective on the world, a world that had grown with the discovery of the Americas. Rapid developments in geography, cartography and navigation made it possible to undertake the great voyages of discovery of the time. New trading routes brought valuable goods to Europe, and increased the prosperity of the merchant cities. Printing had been invented a few decades earlier, bringing Luther the certainty that "The printed word has power". The teachings of humanists such as Erasmus of Rotterdam focused on people as individuals, and artists such as Titian, Leonardo da Vinci, Brueghel and Albrecht Dürer looked to the classical period in their attempts to portray people and their surroundings in a realistic manner. The first pocket watches appeared, and in 1543, during Luther's lifetime, Nicolaus Copernicus declared that the sun was the centre of the universe, thereby ushering in the greatest paradigm shift of the millennium. Luther disagreed with this finding and criticised it, saying "This fool wants to turn the whole art of astronomy on its head". The fact that he was wrong does not alter his tremendous achievement of fomenting a revolution in faith and spirit. Voices everywhere were raised in criticism of the clergy's behaviour, claiming that cardinals, bishops, priests and monks were preaching water and drinking wine. A note made in 1516 by a contemporary chronicler proved that the time was ripe for Luther when he stated: "Many, many people here are just waiting for the right man to speak out against Rome". He was right, and just one year later Luther nailed his theses to the church door in Wittenberg.