As far as i know, a dimension is basically spatial parameters in which "stuff" can move. I think that what bugs me the most about physics is that we know the what but not always the why... obviously this is not anyone's fault especially because finding out why things are the way they are is much harder than figuring out what they are/do. So my question about dimensions is do they actually exist? or are they produced by other laws? i.e. you have time, objects, and forces so thus velocity is born. velocity isn't really a thing you can "touch"... its just what happens when other laws are taken into consideration. So to explain the question and where it comes from... imagine that their is a universe in which forces only pushed on a flat plain... not because they couldn't push in a Z direction... just that they didn't. If no laws (such as the ones in our universe) forced the objects inhabiting this theoretical universe to move in the Z direction then would this universe technically be considered 2D? lets say one day for some reason a force comes along and pushes one of the objects in the 2D universe into the Z direction... the 2D universe would now be transformed into a 3D universe. So if this is true then dimensions should not really be "things" but just an effect of the directions that forces push. So this being said... our universe has the potential to be 20D but no forces "push" in thows directions so we are stuck in our mundane 4D (11D if you like). Im not sure if what i said is how dimensions work and would like to know if it is because it seems to make sense to me... thou i can already sort of spot some problems with it... So are dimensions based on the direction forces in a universe? or is it something else?