Board Thread:Naruto Discussions/@comment-31074250-20170410160032/@comment-734582-20170411082256

DC52 wrote: ... the extent of her dimensions is known. Except it's not. For all we know, all planets are in the same star system. There's nothing to suggest that the stars are unique.

In any case, it's clear that Kaguya's use of "dimension" is absolutely nothing like, say, Obito's dimension. Obito had a weird crystalline world, whereas Kaguya's are honest-to-god planets.