Magellan, an immigrant studying abroad

From a political and economic point of view, Columbus, of course.

The discovery of America led to the great immigration of Europe, and formed a series of countries such as the United States and Canada today. Economically, the plunder of American colonies and the income from selling black slaves to the United States formed the primitive accumulation of capitalism, which made Europe embark on the capitalist road and completely changed the face of the world.

It would be more meaningful if Magellan's voyage proved that the earth is a sphere from the perspective of astronomy and geography.