The point is that there are many relatively straightforward ways to calculate curvature, from the sunrise/sunset technique to Erastothenes to watching sailing s

The point is that there are many relatively straightforward ways to calculate curvature, from the sunrise/sunset technique to Erastothenes to watching sailing ships dip below the horizon and many more. The math may be beyond some people but the effects at play cannot be explained by a flat Earth. Part of the overall thread was along the lines of we should respect flat earthers, they improve rigour. It seems to me that the only sensible responses to that are the counter illustrations of just easily disproved a notion it is. Far more effort goes into supporting this ridiculousness than did into establishing rough shape and size.