Thirty spokes converge upon a single hub;
It is on the hole in the center that the use of the cart hinges.
We make a vessel from a lump of clay;
It is the empty space within the vessel that makes it useful.
We make doors and windows for a room;
But it is these empty spaces that make the room livable.
Thus, while the tangible has advantages, it is the intangible that
makes it useful.
Tao Teh Ching
This second series develops the theme of circles further. Each circle is losing more and more its shape and becomes a trace of something. The door disappears and opens the wide space of the future. We have to pass the entrance and we have to discover the new.