Our story begins 600 years ago. The Europeans of the 15th century had a view of the world that was completely different to our current worldview. For example, many people still believed that the Earth was not spherical, but flat. As well, belief in the geocentric model of the universe, according to which the Earth is at the center of the universe and the Sun and the stars revolve around it, was still commonplace. But what exactly did people at the time imagine the Earth to look like? In answering this question, it might be useful to consider the worldview of the 2nd century Greek geographer Ptolemy, since many of the maps of the world produced in Europe in the 15th century were based on Ptolemy's model of the earth. In other words, we can get some idea of how Europeans living at the time saw "the world" by looking at these maps.
Ptolemy's world mapLooking at this world map, we can see how the areas in and around Europe are shown in relative detail, while areas to the East are rather sketchy. We can also see that the south of Africa is connected to Asia via an unknown continent, while the Indian Ocean is portrayed as an inland sea. The area south along the west coast of Africa was thought to include a dangerous stretch of ocean that was home to lurking monsters and boiling waters among other things, and prior to the Age of Discovery there were no navigators capable of overcoming their fears and leading their vessels into this region. In the 15th century, however, developments in the art of navigation and shipbuilding techniques made extended voyages a possibility, and Prince Henry of Portugal, who later became known as Henry the Navigator, began making plans for a voyage to explore the south of Africa. Over a period of some 40 years, Henry's navigators undertook a series of voyages into these perilous waters, edging further south on each occasion. Eventually, in 1488, nearly 30 years after the death of Henry the Navigator, the Portuguese navigator Bartolomeu Dias reached the southernmost point of Africa. John II, the king of Portugal at the time, named the headland discovered by Dias the Cape of Good Hope. Later, Columbus and Magellan embarked on further voyages as the Age of Discovery continued.
As a result of the courageous exploits of these and other navigators, in the short space of a single century, world maps were completely redrawn and the European worldview transformed. When explorers like Dias and Columbus set off on their voyages of discovery, their model of the earth was not that much different from that shown on Ptolemy's world map, which had been regarded as an article of faith for more than a thousand years, and so their mission was to explore those parts of the world that did not appear on Ptolemy's map. In a sense, what they did was so bold it would not be unlike someone today deciding to head off to Mars or Jupiter.
Incidentally, because history is so often told from a Western perspective, we tend to think that western Europeans in the Age of Discovery were the first people in the world to embark on long ocean voyages, but in fact the Vikings of Scandinavia, as well as people in Asia and the Muslim world, were already familiar with many ocean routes. It could even be said that the Western Europeans were slow off the blocks when it came to ocean navigation. During the Ming dynasty, for example, the Chinese mariner Zheng He led as many as seven fleets of Chinese junks on ocean voyages, reaching the east coast of Africa in the early 15th century. Moreover, the pilot on Vasco da Gama's ship when he reached India, thereby establishing a sea route from Europe, was an Arab navigator by the name of Ahmed ibn Majid. And going back ever further, as early as 2000 B.C., Polynesian people were crisscrossing the Pacific Ocean at will in small vessels.
Furthermore, the Age of Discovery fostered the subsequent hegemony and imperialism of Western Europe, giving rise to countless negative consequences in the form of such things as the slaughter of native populations, colonialism, and the slave trade. Columbus's "discovery" of America was only a discovery from the point of view of the West, since at the time indigenous people were already well established throughout the continent.
For these reasons, when we look back at the Age of Discovery from a modern perspective, it is clear that its historical significance lies in more than simply the discovery of ocean routes and the global expansion of the great Western powers. Of equal significance was the fact that the intellectual craving of the West expanded on a global scale, enabling maps to be drawn up in which the entire world was set out on a single sheet of paper, and facilitating the rapid concentration of knowledge from different civilizations and cultures. In other words, the Age of Discovery could also be described as a period in which this planet we call Earth began to rid itself of superstitions and legends, and in which we began to understand the entire world in scientific terms.