Earlier quoted context omitted.
But we can't perfectly simulate a rock, or a nuclear reaction. Perfect is an extremely high bar here. It would probably be difficult to simulate a rock sufficiently well to fool someone with the combined skills of a geologist & 3D graphic designer.
I'm not suggesting we can do this today (no universal theory), and I'm not suggesting it is practical in the sense that we can simulate that much amount of matter in a certain amount of time. But I think it's theoretically possible. There is also the question about how much simulation would be necessary to get approximately real life results that includes consciousness -There was a very detailed simulation of a cell[…
But keep in mind that a simulation is, well, a simulation. Artificial consciousness may be possible. It may also be possible to simulate something with a surface appearance indistinguishable from consciousness but not actually be consciousness, while actual consciousness would require very different methods.
When thinking about these things we have to draw a line between something that can fool gross human perception and something that is actually conscious. Right now we don't even know enough to know what the tools required to make such a determination would look like. It may very well be that, from an ethical standpoint, we'll need to ascribe consciousness to systems for year or decades before we're able to determine if it's real or the equivalent of a very convincing optical illusion.