ball of torus

thingiverse

The Torsion's Perfect Orb. Note that the Torsion is a mathematical construct that creates a Torus shape when two concentric circles are twisted. The Torsion can be thought of as the difference between the curvature of a circle and the curvature of its center. The curvature of the circle itself is measured by the rate at which it changes direction, or how much it bends in a given amount of space. On the other hand, the curvature of the center is determined by the rate at which the circle moves through space, or how fast it changes direction. When these two curvatures are subtracted from one another, they form a perfect sphere.