i was recently reading "the elegant universe" by bryan greene and i found a problem. first, how can there be, as i understand it, a curled up dimention at every point in space? the curled up dimentions dont touch, i presume, so there must be some space in between them, which i don't think is in accordance with the rest of the theory. also, space is symmetrical, namely matter doen't change as it travels or is translated through space. so how does matter travel through the curled up dimentions without somehow changing? finally, what keeps the curled up dimentions from moving? is there some force in between them, or do they in fact touch? there is probably a rather simple explenation to these questions and i would appreciate it if someone could help. i was a firm believer in string theory until these problems came up. thanks.