EN_rugball 20210824.20220813
Rugball (the term was created by shortening the English words “rugby” and “ball“) is a geometric shape that resembles a pointed rugby ball with constant curvature. The shape is created by rotating the circle around the secant, i.e. around the chord, passing through the circle. Such shape turns out to be practical for making visible the three-dimensional (3D) propagation of light through the Universe, if we model the space of the Universe as a closed space with constant curvature. If the observed source of radiation is at one tip of this “rugball” and the observer is at the other tip, the light from the source will spread to the observer along its surface. In other words, the SUBSTITUTIVE CIRCLES, which replace the straight direction in spaces with constant curvature, lie on the surface of the “rugball” in such a way that they connect both tips.