You could measure 4 millimeters of curvature in a 4000-year-old stone edge 230 meters long in aerial photos taken in the 1940's?
Chuck, I've got a real nice lake out here in Gaines County that you might be interested in purchasing. Pretty inexpensively, too, and it comes with all its lakefront property......
"The Christian church, in its attitude toward science, shows the mind of a more or less enlightened man of the Thirteenth Century. It no longer believes that the earth is flat, but it is still convinced that prayer can cure after medicine fails." H L Mencken