https://en.wikipedia.org/wiki/Sphere_Within_Sphere
https://www.amusingplanet.com/2015/06/sphere-within-sphere-by-arnaldo-pomodoro.html
https://joyofmuseums.com/artists-index/public-art/sphere-within-sphere-by-arnaldo-pomodoro/
https://www.theothersideofmidnight.com/2023-01-29-em-team-confirmation-of-an-artificial-moon rch
