In which century people thought the world was flat?

Answer 1

In ancient times people knew that the world was round, as well as many other scientific facts. This information was lost in Europe when Rome fell to the barbarians about 450 a.d., although it continued to be taught in Arabic universities. In 1050 the European Crusaders conquered the city of Toledo, in Moorish (Arabic) Spain, and gained access to the university there. The refound information slowly worked its way into European culture, and resulted in the Renaissance, beginning in the early 14th century. When Columbus undertook his voyage to the New World many people in Europe knew that the Earth was round, but it was not, by any means, universally known. Therefore, Europeans thought that the Earth was flat for about a thousand years. Almost everybody else always knew that it was round.