From the Dune Main Quote: "Soon they'll begin to fold space." -- Duke Leto. And from Dune's
Relationship to the Core Wave: ""Does space itself have an inside and an outside?" -- Robert C. Cohen.
And then the main quote from No Inside / No Outside: "There is no distinction between inside and outside"
-- D. Vanier
The whole idea of "folding space" and the lack of distinction between inside and outside is, to me, another
way of looking at the hypersphere's addition of time as a fourth spacial dimension.