Ok, so 2 objects in contact with one another exert a normal force pair between the 2, but it is my understanding that they never 'touch' each other, rather, it is the repulsion of the outer electrons that create the electromagnetic 'normal' force. QUESTION 1: Is there physical space betwen the 2, and how much space? Now next scenarios, 1 object rest atops another object, and they are dropped in free fall. Or a marble is in a circular 'loop the loop' at its critical speed at the top (sq.rt (rg)). In both cases, there is no normal force, and thus, no contact between the objects, or between the marble and its track. QUESTION 2: How much physical space now exists between the 2 objects (or between the marble and track if you like that option better)? Thank you.