Comment by dotdashdashdash on Quantum theory cannot consistently describe the use of itself · 2019-01-02T01:37:02.716Z · LW · GW

I'd say that if a superintelligent cat is trying to predict the outcome of someone's measurement of it in a complicated basis it'll only be more accurate if it uses information about its 'true' state as the observer sees it.

Comment by dotdashdashdash on Quantum theory cannot consistently describe the use of itself · 2018-12-30T20:59:52.352Z · LW · GW

I agree with Scott Aaronson' objections to the paper. I think an inconsistency can be shown with a simpler argument:

Suppose two agents, each of which can be in two states, are prepared like in the paper and Aaronson's post.

Using the reasoning of the paper, if agent A finds it's in the $|1⟩$ state, it can deduce that B is in the $|0⟩$ state, so it can deduce that B is certain that A is in the $|+⟩$ state, so it can be certain that it's in the $|+⟩$ state, so it's not actually in the $|1⟩$ state as it sees itself to be. Then, because A is certain that it's in the $|+⟩$ state, it can deduce that B is in a more complicated state. This can go on infinitely. The problem is that in the first step A assumes it's certain of something when it knows it's in a superposition, and in the paper the details of that superposition matter in the final measurement.