Swans were believed to be white until Dutch explorer Willem de Vlamingh’s 1697 discovery of black swans in Australia, which profoundly changed zoology. It then seemed obvious that “black swans” had to exist because other animals also had varying colors. a “Black Swan” event is an unexpected event, after which experts and even laymen usually conclude: “it was bound to happen . . . similar incidences even have happened before.” Read Full Story