Three types of rock.

[gogobera]

They are igneous, sedimentary, and metamorphic. (Broadly speaking

Comments

[sneakypeteiii]

There's always geophysics, which requires only a parameterization of chemistry over large spatial scales. Plus, you still get to use tour precious wave mechanics.

[gogobera]

That's true. I mean, Dan Lathrop, in the building next to mine, is a geophysicist, and he gets to play with huge amounts of pure liquid sodium…. Wait, that sounds terrifying.