The Oxford Unabridged definition for "vortex" is: "A rapid movement of particles of matter round axis; a whirl of atoms, fluid, or vapor."
Here we use the term vortex in a restricted sense. From place to place there are paths of qi which lead from deep inside the earth up to its surface. Often such a path takes the form of a spiral, curving inward counterclockwise (viewed from above) as it rises to the surface, ending at one or several points. There are some variations on this form, but this seems to be the describe the majority of cases.
In a few cases, this qi flows naturally out at this place up into the air, as sheng qi , swirling up counterclockwise (again as viewed from above), with the the radius of the curve increasing as it rises, as if it were flowing along the surface of a cone:
However this is usually not the case, and the contact place on the earth surfaces must be treated with TB ís to cause the sheng qi to rise up. In most cases, but not all, the qi from below contacts with the surface in a small number of discrete precise points (to which I shall refer as critical points, and these critical points must be identified for successful "opening" of the vortex. Before it is open, we shall call it a latent vortex or a dormant vortex.
When sheng qi rises up out of a sufficient number of opened vortices, it begins to collect and spread in a continuous sheet or canopy over the vortices, about 18 or so miles high (30 or so kilometers). We shall call this a sheng canopy .