Does the idea that everything is made of causes and effects meaningfully constrain experience? Can you coherently say how reality might look, if our universe did not have the kind of structure that appears in a causal model?
No. I literally assign prior probability zero to the statement that the universe is not made out of causes and effects, because there is causal structure in Turing machines and in all Turing-complete models of computation which could make up the Solomonoff prior. Causal structure is a very broad thing—it’s just a sparse graph of interacting entities with a lattice ordering.
I can imagine a universe in which the local ordering I observe doesn’t go as far forward or back as I thought, and the true everything-is-causes-and-effects structure is pushed one layer back to something completely hidden from me. I can imagine a universe in which I’ve falsely inferred an ordering which isn’t there, and getting confused by cycles in a graph that I thought was causal. But a universe with no causality at the lowest layer—I think causality is inherent in too many things, and that after subtracting those things there’s not enough option space left to make a universe out of.
If you can’t imagine an universe that’s not made out of causes and effects than talking about such an universe is meaningless.
To be able to assign a probability zero to the statement that the universe is not made out of causes and effects you have to be able to imagine a universe that’s not made out of causes and effects.
Meaningless statements can’t be true or false. Speaking about their probability makes no sense.
I can imagine a universe in which the local ordering I observe doesn’t go as far forward or back as I thought, and the true everything-is-causes-and-effects structure is pushed one layer back to something completely hidden from me. I can imagine a universe in which I’ve falsely inferred an ordering which isn’t there, and getting confused by cycles in a graph that I thought was causal. But a universe with no causality at the lowest layer—I think causality is inherent in too many things, and that after subtracting those things there’s not enough option space left to make a universe out of.
In other words, causality is the invisible pink unicorn.
The text I quoted in the grandparent seems to be saying that even if the universe doesn’t contain causality, we can always postulate an external causality structure even if most of it can’t be observed.
No. I literally assign prior probability zero to the statement that the universe is not made out of causes and effects, because there is causal structure in Turing machines and in all Turing-complete models of computation which could make up the Solomonoff prior. Causal structure is a very broad thing—it’s just a sparse graph of interacting entities with a lattice ordering.
I can imagine a universe in which the local ordering I observe doesn’t go as far forward or back as I thought, and the true everything-is-causes-and-effects structure is pushed one layer back to something completely hidden from me. I can imagine a universe in which I’ve falsely inferred an ordering which isn’t there, and getting confused by cycles in a graph that I thought was causal. But a universe with no causality at the lowest layer—I think causality is inherent in too many things, and that after subtracting those things there’s not enough option space left to make a universe out of.
I think this is one of the few instances where p(0) is actually appropriate! :)
If you can’t imagine an universe that’s not made out of causes and effects than talking about such an universe is meaningless.
To be able to assign a probability zero to the statement that the universe is not made out of causes and effects you have to be able to imagine a universe that’s not made out of causes and effects.
Meaningless statements can’t be true or false. Speaking about their probability makes no sense.
Before Einstein nobody could imagine without universal time either.
In other words, if you can’t imagine a universe with property X, that’s a fact about you not about the universe.
In other words, causality is the invisible pink unicorn.
I don’t understand this reply at all, except as an indication that I didn’t communicate these concepts as well as I’d hoped.
The text I quoted in the grandparent seems to be saying that even if the universe doesn’t contain causality, we can always postulate an external causality structure even if most of it can’t be observed.