By the ships disappearing below the horizon
Ships can circle the world by water and end in the spot where they began, proving the Earth must be round to the contrary belief that it was flat.
Geo is Greek for Earth, so geocentric means the Earth is at the centre of the Solar System and everything, including the Sun, revolve round the Earth. Observations that led to this - well people see the Sun rise in the east and set in the west. Same with the Moon and planets. So they assumed that the earth was in the middle.
kilikh
Columbus, and all educated Europeans of his time, already knew that the Earth was round. That required no voyage for proof. The trade routes to Asia via the east were controlled by the Turks (via land) and the Portuguese (for the sea route, so Columbus proposed sailing west to reach Asia. His problem was that his estimate of the size of the Earth was incorrect, so when he reached land in the Caribbean, and later on the American continent, he knew how far he had sailed and thought he had reached Asia.
The pirates steal and go round sailing looking for treasure
He sailed west instead of east because he didn't know the existence of North and South America. That's why he bumped into the Americas and thought it was the East Indies. He thought he had found another way, but he really didn't. If he had known about the Americas, he wouldn't have gone that way. He believed that the earth was round and that you could go West to reach India instead of sailing East. Many people did not believe the earth was round or that the earth was so large you couldn't go around it.
umm: "The Earth is round"? ------------------------------------------------ The Earth is not round - it is an oblate spheroid. ---------------------------------------------------------------------------- A (slightly) oblate spheroid seems pretty "round" to me.
By shortening the sailing time from Europe to Asia, ships do not have to sail round Africa.
Pythagoras stated the earth was round
Year around, scientists and people who support science, study the health of planet earth.
he want to prove that the world was round and not flat
The moon rotates round the Earth.