Scale is an admitted aspect of space and is perceived as a continuum of space.
If we attempt to measure the distance between objects at very different scales (say the corner of a book on a table and a molecule of a pen on the table near the book), we find we must include scale as part of the means of locating the objects in space.
From a geometric perspective, this would mean that scale is a required measure of space - beyond length, width, and height and simply by being required to locate an object in space would constitute a 4th dimension of space.
Scale as continuum:
http://htwins.net/scale2/
http://www.youtube.com/watch?v=VgfwCrKe_Fk
Scale as spacial dimension:
http://www.researchgate.net/publication/208599620_Expanding_the_Universe_Space_Numbers_Time_Part_I_-_Expanding_Space