Since I’ve been making you guys wait so long, here’s a teaser of my big Ghost Physics post I’m working on.

Danny’s transformation is catalyzed by his ectosignature (essentially a ghost’s nervous system) attempting to form a ghost body in the same location as his human body. The glowing rings are created by the heat/light of the chemical reaction that transforms his body from regular matter into ectoplasm… he’s basically a tiny transdimensional nuclear reactor. It spreads over his body like flames through a sheet of paper, and smells faintly of chemicals and burnt flesh. So, sorta like getting a perm or bleaching hair? Danny totally smells like a hair salon guys

Also because of ectoplasm’s translucency, you can see rough cross-sections of his human body at certain angles during transformation. That sure is his tibia in the last panel there.