> not that long ago we didn't know that we live on a sphere Actually, the ancient Greeks knew it was a sphere, and everyone knew by the Middle Ages. Surprisin

> not that long ago we didn't know that we live on a sphere Actually, the ancient Greeks knew it was a sphere, and everyone knew by the Middle Ages. Surprisingly perhaps, given their other astronomical work, the Chinese were the last hangers on. The notion that we discovered it relatively recently seems to have been due to a propaganda campaign in the 19th Century.