Hm. So then do we have two types of problems you're claiming Bayesian inference isn't good enough for? One is problems involving freebits, and another is problems involving disagreements about reference classes?

The reason I don't think "Earth C" had an impact on the perfect-prediction-except-for-isolated-qubits case is because I'd turned the reference class problem into an information content problem, which actually does have a correct solution.

where it's not even obvious that there is a "true, pre-existing answer" out there in the world

I think this is the normal and acceptable state of affairs for all probability assignments.

how does the superintelligence know it should assume the uniform distribution, and not some other distribution?

Symmetry arguments? And since our superintelligence understands the working of your brain minus this qubit, the symmetry isn't between choices A and B, but rather between the points on the Bloch sphere of the qubit. Learning that in some microscopically independent trial a qubit had turned out in such a way that you chose B doesn't give the superintelligence any information about your qubit, and so wouldn't change its prediction.

A less-super intelligence, who was uncertain about the function (your brain) that mapped qubits onto decisions, would update in favor of the functions that produced B - the degree to which this mattered would depend on its probability distribution over functions.

I don't deny the enormous value of MaxEnt and other Bayesian-prior-choosing heuristics in countless statistical applications. Indeed, if you forced me at gunpoint to bet on something about which I had Knightian uncertainty, then I too would want to use Bayesian methods, making judicious use of those heuristics!

This still seems weird, though I believe in freebits by your requirement. Why would you want to use Bayesian methods if no guess (in the form of a probability, to be scored according to some rule that rewards good guesses) is better than another on Knightian problems? And if some guess is better than another, why not use the best guess? That's what using probability is all about - if you didn't have incomplete information, you wouldn't need to guess at all.

Take two heretofore identical Earths A and B in an infinite universe and are about to diverge based on your decision, and it's not impossible for a superintelligence to predict this decision, not even probabilistically, because it is based on a freebit:

Suppose you just have the one freebit - it's your standard issue qubit, and you keep it in a box at absolute zero in case you need to make a decision. If this superintelligence can predict you perfectly except for this one qubit, why wouldn't it just assign a uniform probability distribution to the qubit's values and then simulate you for different qubit values to obtain a probability distribution?

I'm probably just confused about something.

I think that the "absolute prediction" question is answered. I mean, I'm acquiring bits of information you can't physically know all the time just by entangling with air molecules that haven't reached you yet. But there's a separate question of "how important is that?" which is a combination of at least two different questions: first "how big an impact does flipping a qubit have on human cognitive actions?" and second "how much do I care that someone can't predict me exactly, if they can predict my macroscopic actions out to a time horizon of minutes / days / years?"

I think you're more concerned about absolute prediction relative to "pretty good" prediction than I am, which is a shame because that's the totally subjective part of the question :)

I suspect TvTropes is the best reference for determining basedness here.

Depends on the rules. Who do I look like, Gary Drescher?

What sort of rules would you implement to keep Newcomb's problem interesting in the fact of coins that you can't predict?

Not bad at all :)

Simple but misleading.

This is because Newcomb's problem is not reliant on the predictor being perfectly accurate. All they need to do is predict you so well that people who one-box walk away with more expected utility than people who two-box. This is easy - even humans can predict other humans this well (though we kinda evolved to be good at it).

So if it's still worth it to one-box even if you're not being copied, what good is an argument that relies on you being copied to work?

Ah, I see. They're offset along the z-direction, rather than in the x-y plane.

Huh.

Sure it's not in plasma?