The physical length of all these spheres is still zero although they appear to be unending. Space then is an expanding spherical field. Now start the points in the outer sphere moving inward. Repeat this process with each new outer sphere and combine these points into lines. The result is a gravitational field.
Gravity is a radial field of inward flowing lines.
Gravity originates at the outer limit of Space. In addition, these inward flowing lines are always perpendicular to the expanding spheres of Space. When the leading points of these inward flowing lines of Gravity reach the center, combine them into a field called Ray. Ray is a one dimensional field that moves outward from a center. You may ask how this is possible but consider a triangle.