(March 29, 2023 at 2:35 pm)Gawdzilla Sama Wrote: Take the morons out to sea. Ships approaching your ship will show their masts first and then the rest of the ship gradually rises over the horizon. If that's an optical illusion the ship's radar is deluded as well, because the radar signature gets larger as more hull appears.
Eratosthenes correctly calculated the circumference of the spherical earth by comparing the length of noon time shadow at two different locations.
One could just as easily have shown this is not cause by a tiny sun sitting over one spot point on a flat earth, but rather by an earth that curves away from a sun, by comparing the length of moon time shadow at three different locations on a meridian.
Modern idiots with access to GPS are apparently too stupid and lazy to do a simple observation that could have been done at little cost 2000 years ago.