A hot bar of iron can "compute" the next state of a hot bar of iron. It cannot compute the next state of any arbitrary program. Can I play Fortnite with nothing more that a hot bar of iron? No, I cannot! Not unless it's compiled to WebAssembly.
You can but it shifts the burden to the decoder. Since an iron bar over some time period has a finite number of states, there exists a decoder that maps state changes in the iron bar to your Fortnite gameplay.
I think a more fair criticism is that you likely cannot choose the decoder without an oracle (ie the causal relationship would be hard to preserve). I think OPs claim is that consciousness, unlike Fortnite, doesn’t depend on being causally related to some external inputs (thus you don’t need oracle to choose the decoder).
> Since an iron bar over some time period has a finite number of states
Citation needed.
He defined these states through spin flips and I assume we sample slower than decoherence. This is a semi classical system without complicated qm effects.
But even if we didn’t restrict ourselves
log(# of states)~entropy
and there is a maximum (and finite) amount of entropy you can have in a finite volume (actually it scales with surface area) before you get a black hole.
The iron bar doesn't strike me as particularly conscious, except perhaps to the degree that elementary particles possess some rudimentary consciousness. (See "panpsychism", the idea that consciousness pervades all matter. Though lately, the reverse seems more likely to me—see Lex Fridman's interview of Donald Hoffman[1].)
[0] https://news.ycombinator.com/item?id=31781234
[1] https://youtube.com/watch?v=h1LucGjqXp4