Hal Finney wrote:

So again, is it enough to look at the natural laws of our universe in order to decide whether the consciousnesses within it are real? Or do we need more? Can we imagine a universe like ours, which follows exactly the same natural laws, but where time doesn't really exist (in some sense), where there is no actual causality? I have trouble with this idea, but I'd be interested to hear from those who think that such a distinction exists.

`For me, it's not that I think it's meaningful to imagine a universe just`

`like ours but without causality, rather it's that I think causality is`

`probably important to deciding whether a particular system in our universe`

`counts as a valid "instantiation" of some observer-moment, and thus`

`contributes to the measure of that observer-moment (which in turn affects`

`the likelihood that I will experience that observer-moment in the future). I`

`think if you run a simulation of an observer, and record the output and`

`write it down in a book which you then make thousands of copies of, the`

`static description in all the books most likely would not have any effect on`

`the measure of that observer, since these descriptions lack the necessary`

`"causal structure". I sort of vaguely imagine all of spacetime as an`

`enormous graph showing the causal links between primitive events, with the`

`number of instantiations basically being the number of spots you could find`

`a particular sub-graph representing an observer-moment embedded in the`

`entire graph; the graphs corresponding to the physical process that we label`

`a "book" would not have the same structure as graphs corresponding to the`

`physical process that we label as a simulation of a particular observer. Of`

`course, as I've discussed with you earlier, I'd also speculate that the`

`appearance of an objective physical universe (the graph representing all of`

`spacetime) somehow emerges from a more basic theory that assigns both`

`absolute and conditional measures to every possible observer-moment (each`

`represented in my visual picture by a sub-graph).`

Jesse