A Son of the Rock

Several of the exhibits at the Talbot Rice Gallery, Edinburgh, when we visited in February featured circles of different sorts, mostly of natural origin, but some not:-

Thios one has a depiction of Copernicus’s heliocentric solar system in the book at the centre:-

This was on the wall. It looks like the trace of an eccentically orbiting comet or something of that kind:-

Liesegang Rings. I confess I had only heard of Liesegang Rings in a chemical context before this but I now know they occur geologically too, as evidenced below:-