Go over the threshold 过关: hand and shoulder
Get to the special spot 窍: tip of the elbow, inner spot of kua to come out, back of the knee to find alignment, spot at the bottom of the neck
Master Chen explained the switching of the kuas again, how they are like two credit cards touching each other in a T configuration. We need to create a gap and then do the switch.
More on switching on the kua, the T needs to switch from one side to the other.
Another illusion is with the two hands with the middle finger tips touching each other with one palm facing inward, and one hand facing outward. The switch is achieved by rotating at the finger tip touching point ending with each palm facing the opposite direction.
If you have a solid revolving door, you shine light on it to create a shadow on the wall on the other side. The width of the shadow will change as the door revolves.
We need to make the switch within an enclosed space. The kuas must be like ball bearings. Marking a dot on the surface of each kua, the distance between the two dots can change as the kuas rotates.
To actually move the kua, we need to create a small gap at the kua first. It's like two strong magnets stuck to each other. We need to pull them apart (detach them) a little bit first before we can change the way they attach to each other. Another way is to change add another perspective, which is like locking the inside, and moving the outside.