This circumnavigation forever altered the Western world’s ideas about cosmology—the study of the universe and our place in it—as well as geography. It demonstrated, among other things, that the earth was round, that the Americas were not part of India but were actually a separate continent, and that oceans covered most of the earth’s surface. The voyage conclusively demonstrated that the earth is, after all, one world. But it also demonstrated that it was a world of unceasing conflict, both natural and human.
