In the plane, when an object rotates about a fixed point while simultaneously moving away from that point, it traces out a spiral path that constantly curves outward. Rope is often coiled in this manner on a boat’s flat deck. A spiral path can also begin far away from a fixed point when an object rotates about that point while moving ever closer to that point. Think of the tightly wound head of an emerging fern.
In space, a spiral path is traced by an object that rotates about a fixed axis while moving away from that axis, and has the additional freedom to move upward, like a water spout, or like the ridges of a screw traveling from tip to head. A spiral path can even begin at a point and rotate while moving outward and upward, then reaching a widest distance from its axis, spiral inward about the same axis while continuing its upward journey. This is the path of a ship that travels the globe from south pole to north pole with its compass always at a fixed angle to the globe’s meridians, and is called a loxodrome, or rhumb. In space, the artist has the freedom to create a spiral path about one axis, then have the curve turn to spiral about a different axis.