Magic: Source

Nothing is known about the source of magic, that is, what about belief causes the universe to change. On a metaphysical level, the most accepted guesses theorize that the 3-dimensional space we perceive is only three of a higher dimensional space. Belief is the method by which we are able to move about in the higher dimensional space.   One question that theory begs, then, is "does the universe really change, or do we just move to a different part of the n-dimensional space?" Without any way to perceive any higher dimensions, it is impossible to know if this theory is true, much less test any questions that require it being so. The simple response is, "it appears to us that the universe changes. So what if it doesn't?"   Question: Are there pocket dimensions in which aspects of objects can exist, allowing logical and scientific interactions between the two.  e.g., does Change Gravity work because the two objects share a pocket dimension in which their relative densities are changed only in that dimension, preventing the gravitational effect from affecting anything further?