The boundaries between sets of frequencies = perception
This is what we perceive when we see something or notice a difference. It is where they meet that we can know a difference. If everything is a frequency of its own rate, then when these come within range of our notice, the interaction between the difference the at the boundary creates what we perceive. This is a kin to a ‘disturbance of the force…Luke’… the boundary layer is energetically disturbed, creating eddies and whorls that are perceivable and look very much like when salt water meets fresh water in an open expanse. However, for a body it is multi-directional [-MORE-]