A perfect essay by Asimov on the right way to view the world
Another way of looking at it is to ask what is the “curvature” of the earth’s surface Over a considerable length, how much does the surface deviate (on the average) from perfect flatness. The flat-earth theory would make it seem that the surface doesn’t deviate from flatness at all, that its curvature is 0 to the mile.
Nowadays, of course, we are taught that the flat-earth theory is wrong; that it is all wrong, terribly wrong, absolutely. But it isn’t. The curvature of the earth is nearly 0 per mile, so that although the flat-earth theory is wrong, it happens to be nearly right. That’s why the theory lasted so long.