Do all rabbit holes of knowledge eventually just lead to material science and physics? At the lowest levels of understanding, someone had to make a decision on what works best.
Computers → high level programming language → low level programming language → assembly and processor instruction sets → chip design → circuit board design → electricity, speed of light, quantum mechanics
Art → color and light interactions, experience comes through physiology, development of pigments (historical and modern, like vanta black)
Psychology → ultimately just neurochemicals and electrical synapses?
mechanical watches → transfer of potential energy from the spring, friction, oil properties like viscosity, Mohs scale applied to jewels
Related to turtles all the way down.