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by aditya malik
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What's even the point of making decision theories for dealing with perfect predictors (newcomb's paradox) when we know that according to one of our most accepted theories these days (quantum mechanics) the inherent randomness of our universe does not allow perfect prediction even with unlimited current and past knowledge?

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Shmi

83

This is unrelated to quantum in any way. The limit of accuracy to perfection is smooth. That is, it makes sense to 1-box even for a 51% accurate predictor, and the expected utility goes up with accuracy, reaching its maximum for a perfect predictor. 

Vladimir_Nesov

60

according to one of our most accepted theories these days (quantum mechanics) the inherent randomness of our universe

And yet I'm able to perfectly predict that 2+2 is 4. The agents being predicted are abstractions, like behavior of computer programs determined by source code. It doesn't matter for reasoning about an abstraction that its instances of practical importance get to run within physics.

[-]Dagon2-2

In most formulations I've seen the word "you" is used, implying that the reader is the agent being predicted.  I've never seen them limited to trivial agents that a human-level intelligence can predict.  

It's an open question whether it's possible for Omega to exist, who can predict a truly complex intelligence, which is itself modeling the universe including itself.  

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3Vladimir_Nesov
Abstractions I'm referring to are not intended to be limited to simpler agents that a human can predict, there are precise abstractions of you that can only be predicted by superintelligences, as well as imprecise ones that can be predicted by you and other humans, things like theoretically ascribed reputation about specific situations. This almost touches on what's needed for Newcomb's Problem. Obviously Omega can exist for uploads and arbitrarily complex AGIs formulated as abstract programs (these things can run on computers, so Omega could just use a similar computer). An embedded agent modeling the universe including itself is not a real additional difficulty in principle, even if we want to model the universe precisely (if the world is compressible, its shorter description can fit into a smaller agent embedded in the same world, and with quining we can avoid contradictions). Though almost certainly that's not possible to do in our world. But in any case, that's not because self-reference causes trouble.

Raemon

40

My understanding is that perfect predictor decision-thought-experiments are just simplified versions of "pretty good predictor thought experiments." Like, if you. know that Omega is 90% accurate, it's probably still better to one-box.

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