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 in a sphere shape out (IE: you can feel it all around you.) It can be proprioceptive (meaning you feel a change in your body, but don't see it), it has been known to be visual and we do notice it in sound around us. In any fluid system where it occurs it can set up a standing wave pattern that will create a sub frequency with enough power to shake the hydraulic system to bits. This is known as shoddy engineering… lol. It also can happen with air - which is a fluid going through a car. I open my back windows at over 50 mph and I get a standing wave in the backseat of air created from both sides that rattles the car till it shakes… shoddy engineering. That is a boundary condition created by two wave patterns meeting that make a third thing - a disruption pattern. You can also notice extremely loud sound traveling through the air in a shock wave as it impacts your body.
Which brings us to Frequency Gates/Frequency Barriers: conscious information changes frequency states; Which can manifest in your mind, your body, matter or all three. Think Star Trek; 'Shields Up!!' In the quantum world, energy follows thought, as a matter of fact, energy IS consciousness, not just thought, but a manifestation of the trinary consciousness. So it is entirely possible for a consciousness to erect a barrier of a certain frequency level and at the same time BE that frequency barrier, just as Corey Goode can get transported in a sphere that IS a being. Below is a short passage from LO1 (Law of 1) detailing some ways this is accomplished and why.
Ra: I am Ra. Every effort is made to quarantine this planet. However, the network of guardians, much like any other pattern of patrols on whatever level, does not hinder each and every entity from penetrating quarantine, for if request is made in light/love, the Law of One will be met with acquiescence. If the request is not made, due to the slipping through the net, then there is penetration of this net.
Ra: I am Ra. Your query is unclear. Please restate.
Ra: I am Ra. There is contact at the level of light-form or lightbody-being depending upon the vibratory level of the guardian. These guardians sweep reaches of your Earth’s energy fields attempting to be aware of any entities approaching. An entity which is approaching is hailed in the name of the One Creator. Any entity thus hailed is bathed in love/light and will of free will obey the quarantine due to the power of the Law of One.
Ra: I am Ra. To not obey quarantine after being hailed on the level of which we speak would be equivalent to your not stopping upon walking into a solid brick wall.
Ra: I am Ra. The Creator is one being. The vibratory level of those able to reach the quarantine boundaries is such that upon seeing the love/light net it is impossible to break this Law. Therefore, nothing happens. No attempt is made. There is no confrontation. The only beings who are able to penetrate the quarantine are those who discover windows or distortions in the space/time continua surrounding your planet’s energy fields. Through these windows they come. These windows are rare and unpredictable. From <http://www.lawofone.info/results.php?s=12>
Frequency matching and harmonics allow passageway through and bar all else that is not of like vibration. The frequency/vibratory rate is that of light and love. This is the same mechanism that is employed to put protection around your being/self. Unless the frequency is higher or harmonic the vibratory rate of the energy itself makes passage through impossible.
However, there are black magic practitioners that can and do open portals (Parsons, Crowley and Hubbard et al), to create a rift or tear, that can, and do allow things through this love/light barrier of highest order. They pursue dis-harmonies of the greatest power by creating extreme emotional states through torture, blood sacrifice, etc. This creates a very fractious sub-harmonic much like the shoddy engineering mentioned above.
However, simply enough, a heart centered consciousness perceiving this type of shoddy engineering can heal this dis-harmony simply by being. The high frequency of loving thoughts rearrange disarray into harmony very easily. It simply takes noticing. And that is easy, because when the boundaries between sets of frequencies meet, the higher organization will always have the positive dominance. IE: Order fixes messes. (It’s a mom thing…)