Sorry to come to Reddit for this but please help me settle a disagreement between my wife and I:

She is stating that there was a time, probably during the Middle Ages but she isn't sure, when everyone thought the Earth was flat. This was until a scientist discovered that the Earth was round and he was considered a heretic, ect. (I know this treatment happened to Copernicus and Galileo with Aristotelianism vs a helio-centric solar system, but my wife is making a different point).

I am saying that the idea of "everyone thought the Earth was flat" has been widely discredited by historians and was not the case. Ancient Greeks could accurately estimate the circumference of the Earth by using maths, looking at shadows shadows and the position of the sun. In addition, Babylonians and eastern cultures were well into astrology/astronomy and could track movements of starts accurately as well as understand the elliptical movements of planets and stars.

So was there ever really a period when "everyone" thought the earth was flat? Of course I can acknowledge that at those times probably most human beings were otherwise occupied by their miserable lives and didn't even consider the shape of the earth, so everyone could be "everyone considering the shape of the Earth."

Thanks!