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TruePath comments on That Alien Message - Less Wrong

111 Post author: Eliezer_Yudkowsky 22 May 2008 05:55AM

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Comment author: TruePath 07 December 2009 09:33:55PM 2 points [-]

The heart of your argument is that each new bit of information cuts the number of possibilities about the behavior of the universe in half (which BTW is a bad way to put it since the lists on both sides were infinite).

What you've kinda hidden under the rug though is that this conclusion depends on the whopping assumption that the behavior of the underlying behavior of the universe is computable. There is no good reason for this to be true. Indeed, there is a powerful mathematical argument that a non-computable universe would appear to the beings capable of making only computable deductions in it exactly like a universe ruled by computable rules with truly random process.

Indeed if you want to consider EVERY possible universe rather than just the computable ones then you end up in a situation where there are at least continuum many possible ways the universe can behave so even in the limit of infinite time you can never figure it out. I mean it might literally just diagnolize you (one of the fundamental rules might be do whatever so and so truly predicts won't happen).

Comment author: moridinamael 19 May 2011 06:20:55PM 1 point [-]

This is interesting, but I would respond with two observations:

First, this story is supposed to invoke the idea that some AI we are attempting to box can figure out our own universe. Our universe is computable (to within the limits required for our current level of science). So as an allegory, it's something we should be worried about.

Second, I like to think that some population of scientists in the story were pursuing the idea that the outer-universe might not be computable. If they had turned out to be right, I have a feeling we still would have figured out how to get out of the box eventually. It would have merely taken more time.