OK, you can go look this up on-line

About a guy who took a picture across a great lake to the city on the other side.
Which should have been over the edge of the earth.
It was called a mirage by the MSmockinbirdM

Then you can look up something even more incontravertible.
People, using infra-red photography taking picture of cities way over the horizon.
And the cities tall buildings are not leaning back. They are all vertical.

Like i said, every attempt to find the curvature of the earth has failed.

But, all this proves is that we don't know what shape the earth is.
My guess is that it is a flat 3D space embedded into a higher dimension toroid (not the correct term, but we do not have a correct term for the form yet)