And I don't want to hear anything about lenses or perspective.

How about refraction? Or the fact that the same picture taken from a slightly higher altitude shows clearly that there is no curve.

The real lesson here is that what we see often is not what is - which is why science is not the process of merely looking, but the process of rigorously measuring!

In the words of obi wan, "Your eyes can deceive you; don't trust them."