Pythagoras said that earth is round

In the 6th century BC Greek mathematician Pythagoras said that earth is round - but few agreed with him. Greek astronomer Aristarchos said in the 3rd century BC that earth revolves around the sun - but the idea was not accepted.In the 2nd century BC Greek astronomer Erastosthenes accurately measured the distance around the earth at about 40,000 km (24,860 miles) - but nobody believed him.In the 2nd century AD Greek astronomer Ptolemy stated that earth was the centre of the universe - most people believed him for the next 1,400 years.