On 11 Oct 2011, at 22:14, Russell Standish wrote:

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On Tue, Oct 11, 2011 at 06:03:42PM +0200, Bruno Marchal wrote:With COMP, and via your UDA, our observed universe is selected from the set of all infinite strings (which I call descriptions in my book).My non observed "future"; or computational extensions, is selected, making the comp physics explainable in term of statistics on computations. This leads to general physical laws invariant for all observers. There is no selection of a particular computations, just a relative indeterminacy bearing on all computations going through my state. In particular we cannot use Bayes theorem, for example.Like Brent, I don't follow you here.

`See my answer to Brent. Basically, Bayes is induction. Conditional`

`probability is usual deductive-type probability.`

Computations are not infinite strings, but can have infinite strings as inputs, and so infinite strings can play a role in the (re)normalization needed to avoid the infinities of abnormal histories.That wasn't my point. The set of computational extensions is infinite, uncountable cardinality even.

`Yes. A point where Schmidhuber disagreed on this list, but I am glad`

`that we agree on this.`

Without the anthropic principle, ISTM that your theory would suffer the Occam catastrophe fate. How do you avoid that?Is that equivalent with the white rabbits?No, it is quite the opposite problem. As Einstein purportedly said "Everything should be made as simple as possible, but not simpler". Occam's razor theorem, which comes from Solomonoff and Levin's considerations of algorithmic information theory would imply that we don't see anything interesting at all. That is the Occam catastrophe. Something prevents the world from being too simple. I think that something is the Anthropic Principle, but I'm interested if you have an alternative suggestion.

`You can give me a link to this. Does the OCCAM catastrophe relies on`

`Bayes? What would it be with respect of UD*?. I don't use probability`

`at all in my reasoning, except as a result (first person`

`indeterminacy) which transforms physics into a probability or`

`uncertainty or indeterminacy calculus on computations or arithmetical`

`relations, without using Bayes, nor #-thropic principles.`

`If you explain this in your book, remind me the pages, or just the`

`title of your paper (which I have on some of my hard disks). I deduce`

`(or show how to deduce) the necessary physical laws for all machine-`

`observer. I don't infer anything from observations at all (which would`

`be needed to use an anthropic principle and Bayes).`

Bruno http://iridia.ulb.ac.be/~marchal/ -- You received this message because you are subscribed to the Google Groups "Everything List" group. To post to this group, send email to everything-list@googlegroups.com. To unsubscribe from this group, send email to everything-list+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/everything-list?hl=en.