Particle physics: It’s (to our current understanding) describing our universe at the smallest levels and showing us just how wild things are that we can’t see, helping us understand how to build systems in ways we’d never imagine before.

Mineralogy (for lack of a better term): it matters on larger scales than I particularly care about to be honest, I just love seeing a natural crystalline structure and knowing it’s some combination of copper, oxygen, etc etc… I love copper bearing minerals lol azurite and dioptase are so beautiful!