The AIXI proofs seem pretty adequate to me. They may not be useful, but that's different from not working.
It's really not obvious that if you run an AIXI-like AI it will actually do anything other than self-destruct, no matter how much juice you give it. There have been various papers on this theme recently and it's a common LW meme ("AIXI drops an anvil on its head").
By "Searlian reasons" I mean something like emphasizing the difference between syntax and semantics and the difficulty of the grounding problem as representative of this important dichotomy between narrow and general intelligence that philosophers of mind get angry with non-philosophers of mind for ignoring.
I don't think Tipler's not having heard of AIXI is particularly damning, even if true.
It's really not obvious that if you run an AIXI-like AI it will actually do anything other than self-destruct, no matter how much juice you give it. There have been various papers on this theme recently and it's a common LW meme ("AIXI drops an anvil on its head").
I don't think it's obvious it would self-destruct - any more than it's obvious humans will not self-destruct. (And that anvil phrase is common to Eliezer.) The papers you allude to apply just as well to humans.
...I don't think Tipler's not having heard of AIXI is particularly damning,
...has finally been published.
Contents:
The issue consists of responses to Chalmers (2010). Future volumes will contain additional articles from Shulman & Bostrom, Igor Aleksander, Richard Brown, Ray Kurzweil, Pamela McCorduck, Chris Nunn, Arkady Plotnitsky, Jesse Prinz, Susan Schneider, Murray Shanahan, Burt Voorhees, and a response from Chalmers.
McDermott's chapter should be supplemented with this, which he says he didn't have space for in his JCS article.