[quote=@Double Capybara]
[@Cyclone]

<Snipped quote>

The symbology is just to represent distance. The big difference is what is part of Galbar and what is part of the sphere, meaning Galbar has a Sky and an Underground and these cannot be the sphere of Air and Earth as Aristotle says.
[/quote]

For simplicity's sake Sky and Earth are just lumped together into one effective Sphere--Galbar. I think this makes the most sense because Spheres are meant to be very distinct, difficult to traverse, and have binding effects on native objects. Having mortals walk around with their feet on one Sphere and their faces in another for the entirety of their lives seems at conflict with the nature of Spheres as we've established.

We're not following Aristotle's system too rigidly; just the broad strokes.