The simplest way to put it to a non-native speaker is that the fabric of space bends light
Ok, I thought that light bends space but I'm not familiar with any concept of physics.
So since the space bends light, the other part of the continents are not visible or seems to be curved into the shape of a globe.
I can't respond to that, but I'm sure others could.
What about the distance of the sun and the moon?
Illusion or not, I think that astornauts could have felt a 3000 miles trip and not 382 260 Kms.