AIXI can’t find itself in the universe—it can only view the universe as computable, and it itself is uncomputable.
This is probably false. Its programs-hypotheses are computable, but they don’t have to be the universe. And they could be proving useful facts about the universe and about AIXI itself.
Additionally, AIXI could possess a simplified but still useful model of itself. Any one of the already-described Monte-Carlo approximations could provide a starting point.
Humans only ever model imperfect approximations of themselves, and we get by okay.
This is probably false. Its programs-hypotheses are computable, but they don’t have to be the universe. And they could be proving useful facts about the universe and about AIXI itself.
Additionally, AIXI could possess a simplified but still useful model of itself. Any one of the already-described Monte-Carlo approximations could provide a starting point.
Humans only ever model imperfect approximations of themselves, and we get by okay.