“Go, See For Yourself!”
This man joins the (former Air Force Major and Captian) pilots in the jump seat on flight to Honolulu and beginning after sundown watches as the previously set sun rises again when they pass through 21,000 feet, and then stays up all night as they travel to Hawaii at 41,000 feet elevation.
The pilots explain to him the curvature equation, and challenge him to go observe it for himself.
He then visits the North Shore of Oahu and looks 108 Miles Away to Kauai (elev: 5,243 ft.), which is clearly visible to him to the beach level, in full, but should be under thousands of feet of curvature if figured at 8 inches per mile squared. The entire island of Kauai should be hidden by an excess of 400 feet of curvature beyond the full island height! (6,000 to 7,000 feet of obscurity)
The Isle of Kauai as seen from Oahu’s Northern Shore Mountains, but the man claims he saw from the shoreline.