Just look around the open field. Naively, one could come up with the idea.
The spherical shape of the earth was discovered by clever observers already in antiquity.But it is absolutely counter-intuitive — a naive listener would doubt that without appropriate training.
The rest of this post is an update of my first response.Thanks to Gerhard Heinrich for the hints.
The ancient observers (Erathostenes).saw the earth’s shadow during lunar eclipses, and found that it is round. They observed the shadows of a vertical rod at the highest level of the sun in different places and found that it was different in the sky depending on the “geographical latitude” (according to today’s terms). They were even able to calculate the radius reasonably precisely (according to .
During the Middle Ages, contrary to popular ideas, including mine until yesterday, this was regarded as a sure knowledge among scholars.The Persian mathematician and scientist Al Biruni has determined the radius up to 1% by measuring the horizon from an elevated point of view (mountain top).
However, there were always voices, especially from the religious camp, who rejected the spherical figure as incompatible with the Bible.Among them were popes. It is not clear to me whether the “simple people” should be kept in the faith; in any case, the spherical shape, along with its radius, was undisputed among the vast majority of scholars.
The “rediscovery of the flat earth” probably goes back to Washington Irving, an American historian who spent a long time in Spain in the 19th century.He discovered the figure of Columbus and his journey, which was almost perfect for the American reader. After all, such a Spaniard/Portuguese had discovered America, not the hated British. Of course, this included an exaggeration as a genius, who had discovered the proverbial “egg of Columbus” with the spherical figure. For this, however, the prehistory had to be rewritten, which inevitably led to the reintroduction of the medieval faith in the flat earth into the academic discourse.
Compare Flat Earth Myth
Columbus, by the way, was certainly not the genius or even the first.Rather, he had calculated himself superbly at the perimeter of the earth, or he had a source that had been superbly accounted for. From this he concluded that the trip to India “back around” would not be as far as always feared. Fortunately, America was in the way, otherwise the mission would have ended in disaster, and we would never have heard of it again.
The fact that “Flat-Earthers” are becoming popular again in a certain way is tragic in several respects, since they go back not only to the pre-enlightenment (as I originally assumed) but even to pre-antiquity.