Re: .. and another thing...
It can help to think about additional dimensions as a tiny circle at every point in space/spacetime (start with a 2D grid - it's easier...), with your position around the circumference representing your position in that dimension.
It is then possible to envisage a situation where this dimension is not necessarily spatial (or visible/navigable), but is a representation of a (scalar) quantity at that point (like an all-pervading field), but potentially detectable.
The Lee Smolin book I mentioned above gives the above analogy which is quite helpful.
Biting the hand that feeds IT
