These shapes are universally understood as round. From the invention of the wheel to the ball-bearings inside the hubs of progress, round is everything. With work inventions aside, taken for granted is the thought that people almost praise round (objects) everyday in recreational sports! They follow the bouncing ball as if life's instructions were attached. So, as 'masters of the obvious' have probably said: "the ball is in your court; run with it as you will". 

MusicArtists 'WIRE' use circulative reference throughout their library of music, most notably their '154' release. Selections include: 'Blessed State', being a most positive song (almost prayer like) in appreciation of our planet earth. The song itself says it straight forward / best, almost similar to a quasi time-warp of the adage: 'to stop and smell the roses'; 'Map Reference' fires up visions in imagination of explorers and hierarchies, almost within a geography / geometry lesson, seemingly touching the mathematical definition of pi (3.14 ... etc.). Other songs with mention or reference of round circular
spheres are: 'A Mutual Friend' (moon), 'On Returning' (sun), 'Indirect Inquiries' (sun), '40 Versions' (moon). To further connect, 'A Mutual Friend' includes mention of the horizon and months of the year (time is circular based) and 'The Other Window' mentions time passing.