math-y thought. Discrete vs continuous? Discrete. fraction/fractal/fracture compels me to have granularity/kernel/zoom/scale always in mind.

Injection of air into a water-saturated bed of grains causes fracturing and deformation of the granular packing.

Campbell et al., Gas-driven fracturing of saturated granular media. Phys. Rev. Appl. 8, 064029 (2017).

Image credit: James Campbell

via https://complexflowlab.com/gallery-of-complex-flow/