I currently disagree with your conclusion about many worlds (I want to take modus tollens where you take modus ponens), but I think this is a really nice conundrum.
(What is discrete knowledge? It is knowledge that some nontrivial proposition X is definitely true. The sort of knowledge a Bayesian may update on, and the sort of knowledge that logic applies to.)
Bayesianism still believes in events, which are facts about the world. So the same problem comes up there, even if no fact can be known with certainty.
(in other words: the same problems that apply to 100% justification of belief apply to 99% justification of belief)
So the same problem comes up there, even if no fact can be known with certainty.
If so, it seems to require a different argument to point to the problem in that case, since your argument in the post relied on “discrete knowledge”.
I don’t currently see what stops a radical probabilist from interpreting evidence as unreliable information about the wave function.
(I do have an intuition that this’ll be problematic; I’m just saying that I don’t currently see the argument, and I think it’s different from the argument in the post.)
I’m a little confused: you reject physicalism, and yet you seem to be speaking from a physicalist ontology here, requiring there to be a physical fact (a true configuration) or no fact at all (no indexical information).
I believe there are physical theories and physical facts, but that not all facts are straightforwardly physical (although, perhaps these are indirectly physical in a way that requires significant philosophical and conceptual work to determine, and which has degrees of freedom).
The issue in this post is about physical facts, e.g. measurements, needing to be interpreted in terms of a physical reality. These interpretations are required to have explanatory physical theories even if there are also non-physical facts.
Hmmm. So facts aren’t exclusively physical in nature, but physical theories need to do all their explanatory work on their own, without reference to any of the nonphysical facts? I’m still pretty confused. The post makes a lot more sense to me if I read it as yet another puzzle for physicalism, rather than something directly related to your actual ontology.
Naively (ie in my naive understanding) it seems like an agent-centric perspective (ie the opposite of a view from nowhere) is more or less like Solomonoff induction (so e.g. solves anthropic reasoning via UDASSA). The world is built outward from the agent, rather than the other way around, but we still get something like indexical facts. So many-worlds seems ok.
It’s rather nonstandard to consider things like photon measurements to be nonphysical facts. Presumably, these come within the domain of physical theories.
Suppose we go with Solomonoff induction. Then we only adopt physical theories that explain observations happening over subjective time. These observations include discrete physical measurements.
It’s not hard to see how Bohm explains these measurements: they are facts about the true configuration history.
It is hard to see how many worlds explains these measurements. Some sort of bridge law is required. The straightworward way of specifying the bridge law is the Bohm interpretation.
I currently disagree with your conclusion about many worlds (I want to take modus tollens where you take modus ponens), but I think this is a really nice conundrum.
There is no reason rational agents need to assign 100% probability to anything. Eliezer rejected it long ago, although he seemingly missed the implied rejection of Bayesian updates.
Bayesianism still believes in events, which are facts about the world. So the same problem comes up there, even if no fact can be known with certainty.
(in other words: the same problems that apply to 100% justification of belief apply to 99% justification of belief)
If so, it seems to require a different argument to point to the problem in that case, since your argument in the post relied on “discrete knowledge”.
I don’t currently see what stops a radical probabilist from interpreting evidence as unreliable information about the wave function.
(I do have an intuition that this’ll be problematic; I’m just saying that I don’t currently see the argument, and I think it’s different from the argument in the post.)
Yes the argument has to be changed but that’s mostly an issue of wording. Just replace discrete knowledge with discrete factual evidence.
If a Bayesian sees that the detector has detected a photon, how is that evidence about the wave function?
I’m a little confused: you reject physicalism, and yet you seem to be speaking from a physicalist ontology here, requiring there to be a physical fact (a true configuration) or no fact at all (no indexical information).
I believe there are physical theories and physical facts, but that not all facts are straightforwardly physical (although, perhaps these are indirectly physical in a way that requires significant philosophical and conceptual work to determine, and which has degrees of freedom).
The issue in this post is about physical facts, e.g. measurements, needing to be interpreted in terms of a physical reality. These interpretations are required to have explanatory physical theories even if there are also non-physical facts.
Hmmm. So facts aren’t exclusively physical in nature, but physical theories need to do all their explanatory work on their own, without reference to any of the nonphysical facts? I’m still pretty confused. The post makes a lot more sense to me if I read it as yet another puzzle for physicalism, rather than something directly related to your actual ontology.
Naively (ie in my naive understanding) it seems like an agent-centric perspective (ie the opposite of a view from nowhere) is more or less like Solomonoff induction (so e.g. solves anthropic reasoning via UDASSA). The world is built outward from the agent, rather than the other way around, but we still get something like indexical facts. So many-worlds seems ok.
It’s rather nonstandard to consider things like photon measurements to be nonphysical facts. Presumably, these come within the domain of physical theories.
Suppose we go with Solomonoff induction. Then we only adopt physical theories that explain observations happening over subjective time. These observations include discrete physical measurements.
It’s not hard to see how Bohm explains these measurements: they are facts about the true configuration history.
It is hard to see how many worlds explains these measurements. Some sort of bridge law is required. The straightworward way of specifying the bridge law is the Bohm interpretation.