I was thinking about kaluza-klein theory again, and what might control the size of the extra dimensions. Kaluza Klein theory says that the universe has small extra dimensions that we can't see, kind of like a sheet of paper looks 2D, but actually has a small thickness.
Anyway, I was wondering, why does the thickness have to be constant? Imagine if the extra dimensions were being constricted by mass. In regions close to a star, they would be almost impossible to detect. But out in deep space, either interstellar, or if you want to be less extreme, intergalactic, they would be actually noticable. If you went out there, your atoms would gradually fall apart. Some physicists already believe gravity is "leaking" into extra dimensions. It might also explain some of the annoying things that require dark matter/energy. Any thoughts on this idea?