Continuing on from the Yin/Yang sine wave created by your breathing in and out.
There are lots of other sine waves created by your 3-Step Yang/Yin exercise. Notice how it fits in well with the T'ai chi t'u design, sine wave and all.
Suppose we extend this design into the third dimension.
As you walk, look straight ahead and do a sensory yawn.
Notice that, when you have your senses expanded, especially your vision, the horizon bobs up and down as you walk. Of course it does this annoying thing all the time when we walk, even worse when we run.
Physically dampen the up down bounce by flexing the knees a bit more and trying to hold your head absolutely level like a high fashion model.
Then exaggerate the up down motion by flexing the ankle, giving a bounce to your walk. Normally our brain automatically filters the up down movement out of our vision. But if you take along your video camera and tried to take a video picture while walking or running the resulting bouncing image will drive your viewers bonkers. The sensory yawn goes below the sensory filters, so, looking ahead a ways, you see the world bobbing up and down like an amateur video.
The up and down motion caused by your stride describes a sine wave that is vertical to the ground. This one is easy to visualize because you actually see it by the way the horizon moves up and down as you walk. It is also useful because, to see the vertical wave, you have to by-pass the automatic sensory filters and remain in an expanded state of sensory awareness.
Observe the vertical sine wave and the horizontal one of your breathing happening together. Think about the differences between them. As you consider the aspects of the sine waves you have to be:
Actually observing the waves. Observing the horizon moving. Observing the chest expanding and contracting.
Thinking the words yin and yang at the correct time with your expanding and contracting chest.
Feeling the air moving into you and flowing out of you.
Keeping the 3-step in phase as you running down the road, too, watching out for cars and enjoying the scenery as it bobs up and down.
Pay attention to how you feel; to the process of mental reflection when you observe the difference between these two kinds of polarity. You are messing about below the conscious mind filters but still trying to think consciously, rationally, in this environment.
Which is why you'd better get pretty good at the Yin Yang business and be familiar with your exercise path before trying this exercise. Here are some fine points to experience and think about.
There is one wave per step in time with both your stride and heart beat, a frequency of about 2 cycles per second (if you are doing Richard's 3 Step correctly).
There are three vertical waves for each horizontal breathing wave.
Up and down is a different category than right and left, and different again from in and out.
Yin and Yang seems less appropriate on the vertical polar axis (up and down does not correlate well with thinking about in and out).
The up and down sine wave is not bilateral but is created by your bipedal, forward motion. It brings you towards your objective.
The left and right sine wave created by your breathing is bilateral but is created by the unitary expansion of your chest. It brings your objective (air) into yourself.
After you have done this for a few days and have the thing down pat, stir in the final ingredient.
There is another wave action.
It is generated by the harmonic activity of the brain. If you have seen an EEG of brain waves you know this is a real mess of frequencies. But there is one frequency, at 10 cycles per second (vibrating 5 times faster than your step/heart pace) connected with a deep state of meditation. Harmony. The alpha rhythm. Good stuff.
So add it in. Visualize a sine wave of 10 beats per second as a harmony between your eyes and the vision of the world (inside of you).
To do this you need to make the same kind of mental shift you made when you changed the focus of your breathing from air coming into you to air going away from the atmosphere.
Only now you simply reverse the mental image you have of a world bobbing up and down in front of you to the understanding that this "view" is bobbing up and down because your head is moving up and down and the image being formed is not outside of you, but inside of you.
So layer your visualization of the 10 cycle frequency on top of the 2 cycle vertical step curve you can clearly see as you walk.
I don't know how to tell you to do this. But for me, when I simply try, I can feel that frequency like a hum, an oscillation, and when I get it all moving just right, the blood pumping with the legs, the sensory yawn wide open, I actually see the world vibrate at this frequency - while bobbing up and down like a bad video and waving in and out with each breath.
As long as all the other parts are in three-step harmony, the alpha beat just seems to be there, naturally. I saw it first and then understood what it was.
When you experience this trio of wave sets, you are just a decision away from experiencing The Thread of Awareness. Could happen. Can't ever tell. It just does. You'll know.
If you do or don't, the exercise is good training for having the experience. It brightens up your experience of the world you are three stepping through.