The way it is displayed. So lets take a beach ball, and you want to see it all on a flat surface. You cut it in four corners, then lay it flat. This is done in that way. So it is spread out as such.

These explorers even included lattitude lines, circular too. And they show the space on top the artic ocean.

Also gravity just makes things spherical, that is what happens to a magnet surrounded by iron flakes.

Many things are just simple, and easily testable