>>21499466You have to measure, not imagine things. You need to know how your eyes work. You have perspective in the 3 dimensional world, you have atmosphere, you are looking through a lot of air which acts like a lens in the ever increasing distance. The limit of your vision is the horizon, it's not a physical barrier of an edge of a ball. Things also get smaller in the distance, and smaller and smaller the farther away they are. You can't see the pyramids or mount everest because it's a tiny speck from where you are and it's behind lots and lots of atmosphere and other things that are closer to you and are visually bigger and block your view.
You can also ask the other question; what do you even think an endless level plane would look like? Can you draw one? An endless open air room with clouds and hills and everything. It looks exactly like reality does.
Water also mirrors in perfect proportion all the way dozens of miles to your horizon, as a perfectly flat surface does.
