“Test the curve math”? You mean like how people noticed that the last part of a ship that they could see as it sailed away from them was its mast? That kind of a curve test?
Yes and when they zoomed in on the ship, they saw the rest of the ship? Yes... that kind of test.
Keep in mind the formula for curve. It’s really a severe drop, and not that hard to prove or disprove with a good camera.