Hi, Neeid, thank you for invitation.

This is the right question - but currently I don't see any meaningful limitation for Aether density - at least conceptually. But the Aether is just an abstract concept by its very definition, it can be never seen in its full extent. So that is possible, some practical limit for Aether density observation exists and such limit would define the scope of the whole observable Universe by the same way, when you're using a lantern in dense fog - what you'll see is the spherical zone of illuminated fog, not the whole space. The principal limitation of the observable Universe size and density is the speed of light, for example.

Another limitation follows from geometry constraints. For example, I speculated, the Universe is formed by fractal foam, so that the most dense portion of reality is formed just by many combination of existing paths. You know, when we appear inside of large maze or foam, the number of paths perceived increases greatly with the maze or foam size, so it can appear much larger, then it really is.

http://superstruny.aspweb.cz/images/...dientfoam1.gif

Another question is, why we should ask about Universe limits - the only number, which doesn't require any further reasoning is just the infinity.