Positive proof that the earth is not a sphere

If the earth were roughly an ellipsoid (even more roughly a sphere) approximately 8000 miles in diameter, it would imply several things that are clearly false (Update 2020: This post is satire):

1. If there were a row of identical ships receding into the distance, their crow's nests would not form a straight line, but instead the middle crow's nests would jut above the line of sight from the near crow's nest to the far crow's nest.
2. No four cities spaced at least 8,000 miles from each other would be plottable on any flat map with reasonably accurate distances among them all.
3. A flight from Sao Paulo to Johannesburg would be about as fast as a flight from Chicago to Paris.
4. Warning lights to protect ships from treacherous rocks would have to be placed 150 feet high just to be seen 15 miles away.
5. Sailors would only be able to see other ships 6 miles away if they and the other ship were more than 6 feet above the water or 8 miles away if they and the other ship were more than 10 feet above the water. 
6. Surveyors running high accuracy level loops would have to make sure their telescopes were looking equal distances in both directions to avoid Round Earth curvature errors.
7. Radio ships could be sent spinning around the earth fast enough to appear suspended instead of needing either a tower or a lighter-than-air balloon to stay aloft.
8. If enough radio ships were placed above the earth, you could conceivably know exactly where you were at all times by talking to the radio ships. You might not even need maps and compasses even in the middle of the Pacific Ocean.

;-)