Ed talks about where here is in relation to the supernatural domain:
With rare exception, all of the Christians I’ve ever met ascribe to some version “Heaven” as somewhere different from here and now. But it seems most of the time a mere idea. It’s not part of their calculus of life. They act as if it’s not real; they talk and write and construct a whole framework that denies it. This denial is pervasive. The belief is not a truth, but a mere fact for them, and has precious little effect on how they operate. It’s always out there somewhere and they aren’t striving to connect directly. It’s an orthodoxy without faith.
I can recall a session in the NATO chapel with a bunch of teenagers from those military families in the chapel. I tried to convey the concept of our universe as a mere bubble with distinct boundaries and a distinct lifespan existing within a broader existence that has no such boundaries. I used a lot of jargon common to science fiction from those days. I suppose some of them got it, because you could see the proverbial light bulb flash on their faces. But these were kids just a few years from legal adulthood. Why was this so new to them?
I had always considered it similar to how Ed does, though I can’t trace the reasons how that came to be. As he mentioned, it seems to be the favorite basic idea behind many a science-fiction universe premise, though in most cases if the supernatural can be reached through advanced mechanics, it’s not really the supernatural but another level of the physical domain. The “Outside” from the Ender series is a good example of this, though I think there may have been a non-natural factor needed to access it.
Other works play on the co-location idea, but add an element of sound. C.S. Lewis in his space trilogy mentioned our universe existing as a level of vibration, and Tolkein’s Lord of the Rings cosmology involves the singing of angelic beings as the primary force in the creation of Eä—and remember what happened when a hobbit put on the One Ring? Of course, there’s also New Age explanations that borrow this concept of co-located domains of existence.
Maybe the best starting place is drawing some analogous truths between our domain vs the supernatural domain lies in the phenomenon of embryonic gestation and the natal process. I have some ideas that came from that, but that’s a post for another day.