This whole concept of living on the inside of something (as opposed to the outside, like we do) reminds me of the theory that arose during the mid 20th century that suggested that we lived on the INSIDE of the earth.  Of course it didn't last long, but it was interesting nonetheless.

The whole theory was about mirroring the whole universe at the surface of the earth. Then there would be all the universe (including us) inside the earth and the earth outside. Since it is just a mirroring, it hasn't been disproved yet and possibly will never. There were attempts, of course, but you cannot decide whether we live in- or outside the earth from inside the universe. At least that has been proven. So choose, which way you like more  . When you're a scientist, you should stick with the outside version, because that would make most formulas looking easier (but not all). They are all the same of course, just transformed, or better: mirrored.