The inverse square law, aka “butter gun,” can guide our darkroom exposure changes under an enlarger, but it fails with large or volumetric light sources used in alt photo processes.
The law stated for mnemonic ease:

An object twice as far from the light as another recieves one fourth the light.

Oddly, this principle of physics applies to more things than light, including sound, or in my fading memory, butter coating machines at the toast plant… or was that a Taoist plant?