[coldtea]

>But no one is questioning the ability to build a computer that simulates the behavior of a rock; or most other physics-governed systems.

Actually it sounds especially difficult.

A crude approximation (simulation) at best.

Nothing like a full rock, with its full interactions with its full environment (that might need simulating the whole universe), and with oversimplifying most of its properties (molecular interactions, heat dynamics, etc).

Now make it a "wet rock" and we're even further away (and I wont even dare ask for mold on it or anything, much less living micro-organisms)...