It's possible. I mean, wtf do we really even know? Is gravity a function of energy or is it a force upon energy? If it's some unseen force upon energy, then there's obviously something unseen out there. It could be that some stuff, in a parallel dimension, runs concurrently within our dimension. Maybe all the different stuff in our dimension is stuff from other dimensions, but because we can see it, or act upon it, we think of it as something that belongs exclusively to our dimension.
edit on 12/18/2012 by Bleeeeep because: (no reason given)