The overall message of the post sounds reasonable to me, but doesn’t it apply to Pearl’s causality as well? If the world is built from computation rather than causal arrows, how do you get to causal arrows?
If the world is built from computation rather than causal arrows, how do you get to causal arrows?
I had to do a bit of searching, but it seems that Eliezer (or at least Eliezer_2008) considers causal arrows to be more fundamental than computations:
And, if we have “therefore” back, if we have “cause” and “effect” back—and science would be somewhat forlorn without them—then we can hope to retrieve the concept of “computation”. We are not forced to grind up reality into disconnected configurations; there can be glue between them. We can require the amplitude relations between connected volumes of configuration space, to carry out some kind of timeless computation, before we decide that it contains the timeless Now of a conscious mind.
So here’s my understanding of Eliezer_2008′s guess of how all the reductions would work out: mind reduces to computation which reduces to causal arrows which reduces to some sort of similarity relationship between configurations, and the universe fundamentally is a (timeless) set of configurations and their amplitudes.
Interestingly, Pearl himself doesn’t seem nearly as ambitious about how far to push the reduction of “causality” and explains that his theory
takes the physical notions of “mechanisms”, “variables”, “measurements” and “interventions” as the basic primitives.
which bears almost no resemblance to Eliezer’s idea of reducing causality to similarity.
I still don’t understand what Barbour’s theory actually says, and if it says anything at all. It seems to be one of Eliezer’s more bizarre endorsements.
Does this explain it for you, or are you looking for something more detailed?
Barbour is speculating that if we solve the Wheeler-DeWitt equation, we’ll get a single probability distribution over the configuration space of the universe, and all of our experiences can be explained using this distribution alone. Specifically, we don’t need a probability distribution for each instant of time, like in standard QM.
Yeah, that approach seems overcomplicated to me. We shouldn’t ask whether a chunk of matter or information “contains” a conscious mind, we should ask how much it contributes to the experiences of a conscious mind. The most obvious answer is that the contribution depends on how easy it is to compute the mind given that chunk of matter or information, or vice versa. Of course I’m handwaving a lot here, but having actual causal arrows in the territory doesn’t seem to be required, you just need laws of physics that are simple to compute.
The overall message of the post sounds reasonable to me, but doesn’t it apply to Pearl’s causality as well? If the world is built from computation rather than causal arrows, how do you get to causal arrows?
I had to do a bit of searching, but it seems that Eliezer (or at least Eliezer_2008) considers causal arrows to be more fundamental than computations:
So here’s my understanding of Eliezer_2008′s guess of how all the reductions would work out: mind reduces to computation which reduces to causal arrows which reduces to some sort of similarity relationship between configurations, and the universe fundamentally is a (timeless) set of configurations and their amplitudes.
Interestingly, Pearl himself doesn’t seem nearly as ambitious about how far to push the reduction of “causality” and explains that his theory
which bears almost no resemblance to Eliezer’s idea of reducing causality to similarity.
I still don’t understand what Barbour’s theory actually says, and if it says anything at all. It seems to be one of Eliezer’s more bizarre endorsements.
Does this explain it for you, or are you looking for something more detailed?
Yeah, that approach seems overcomplicated to me. We shouldn’t ask whether a chunk of matter or information “contains” a conscious mind, we should ask how much it contributes to the experiences of a conscious mind. The most obvious answer is that the contribution depends on how easy it is to compute the mind given that chunk of matter or information, or vice versa. Of course I’m handwaving a lot here, but having actual causal arrows in the territory doesn’t seem to be required, you just need laws of physics that are simple to compute.