I propose an experment to put this matter to rest. Go to a relatively flat spot on earth (easily done if earth is flat) such as the Bonneville Salt Flats in Utah. Mount a laser on a tripod and set up a target a mile away, both the laser and target set at the exact same height relative to sea level. Fire the laser at the target.
If the earth is flat and there is no curvature the laser will exactly hit the target.
If the earth is round and there is curvature the laser will miss the target by the amound of caluculated curvature over a distance of a mile, whether it be 7.98 inches or 7.98 inches squared.
Now don't say that the government has the area off limits becauces that's simply not true. I kow for a fact that Area 51 is in Nevada and not Utah. I saw this on X-Files.