[AOD] wrote:But I thought that most of the other dimensions, according to String Theory, were all curled up on themselves and so only exist on the Planck level (or something like that?).
Correct. So it doesn't make any sense to talk about moving into them.
For that matter, it wouldn't make sense to talk about moving into another dimension even if the other dimensions
weren't so terribly small. After all, we're not in "a dimension" now. We're in three of them. We could exist in three different dimensions, maybe... but in that case we'd essentially be in another universe anyway.
And as for moving from one universe to another "break[ing] the conservation of matter and energy"... um, and on what possible basis do you say that (where by "you" I don't of course mean [AOD], but rkolter, who [AOD] quoted)? Physics as it stands doesn't really have all that much to say on traveling between universes, and I certainly don't think there's any firm basis for believing that such conservation laws must necessarily hold only within a given universe. They're really empirical laws, remember, based on observation. We haven't observed travel between universes. One could argue that possibly the reason we haven't observed it is that it isn't possible, but I see no good reason for arguing that conservation of matter and energy has anything at all to do with it.
So, really, yes, traveling between universes makes much,
much more sense from a scientific standpoint than traveling between "dimensions".
