What did you see out the window of that plane that proved to you your position was correct?
I know it is a sphere because NASA has produced some very compelling fake images.
The pilot made an announcement and explained that because the plane was flying higher than usual to take advantage of a jet stream, if we looked out the window, we could start seeing the curvature of the earth.
I had a window seat, and wouldn’t you know it, you actually could. It was tiny, but an arc was definitely there.
The pilot then apologized, and said if we were in a Concorde and flew at its elevation, we would see darkness above us and an unmistakable curve on the horizon.
I still get goosebumps thinking about that flight.