[DARISC]

Because we walk upright, and have chosen to define "up" as where our heads are, relative to our feet.

And, we know that the earth rotates on an axis, one end of which is approximately below the North Star.

We have to turn our heads "up" to see the North Star.

Therefore it's logical that we would place a dot "up" at the top of a piece of paper to represent the North Star.

And we would draw a circle somewhat "down" from the dot to represent the Earth.

Also, I think most people visualize a spinning sphere (in this case the Earth) as they visualize a spinning coin or a spinning top, i.e., on an axis plumb to the center of the Earth

That's my hypothesis.

And I'm sticking to it.