Anybody with half a brain can figure out that the Earth is flat. Disagree? Show me curvature that I can actually measure, dumbass, not a Nasa cartoon.
Over 100 miles there should be 1.25 MILES of curvature. That's a very large amount to be missing when you go look for it and can't find it.
They can measure anything else down to milliionths of a inch, second or degree but curvature - nope, sorry folks can't measure it.
That's because there ain't none.