Here's a bit on Eratosthenes' so called experiment:
Listen very carefully to what the heliocentric priest Neil DeGrasse Tyson says, Eratosthenes only used 2 locations.
They can't even decide if it was sticks or a wells that were used. Also how did they verify their findings at the exact time? Sounds more than flawed.
And here is some repeatable tests (I have conducted) that you can do yourself using 3 locations:
All this has been dealt with years ago. And again it's based on visual phenomena and geometry, rather than concentrating on the the physical, tangible geometry.
When I talk about physics, I'm talking about the physical, tangible nature of objects, not theoretical physics.