On 12 Dec 2011, at 04:39, Joseph Knight wrote:

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On Sat, Dec 10, 2011 at 6:39 AM, Bruno Marchal <marc...@ulb.ac.be>wrote:On 09 Dec 2011, at 19:47, Joseph Knight wrote:On Fri, Dec 9, 2011 at 3:55 AM, Bruno Marchal <marc...@ulb.ac.be>wrote:The heap argument was already done when I was working on thethesis, and I answered it by the stroboscopic argument, which hedid understand without problem at that time. Such an argument isalso answered by Chalmers fading qualia paper, and would introducezombie in the mechanist picture. We can go through all of this ifyou are interested, but it would be simpler to study the MGAargument first, for example here:http://old.nabble.com/MGA-1-td20566948.htmlThere are many other errors in Delahaye's PDF, like saying thatthere is no uniform measure on N (but there are just non sigma-additive measures), and also that remark is without purpose becausethe measure bears on infinite histories, like the iterated self-duplication experience, which is part of the UD's work, alreadyillustrates.All along its critics, he confuses truth and validity, practicaland in principle, deduction and speculation, science andcontinental philosophy. He also adds assumptions, and talk like ifI was defending the truth of comp, which I never did (that mistakeis not unfrequent, and is made by people who does not take the timeto read the argument, usually).I proposed him, in 2004, to make a public talk at Lille, so that hecan make his objection publicly, but he did not answer. I have toinsist to get those PDF. I did not expect him to make them publicbefore I answered them, though, and the tone used does not inviteme to answer them with serenity. He has not convinced me, noranyone else, that he takes himself his argument seriously.The only remark which can perhaps be taken seriously about MGA isthe same as the one by Jacques Mallah on this list: the idea that aphysically inactive material piece of machine could have a physicalactivity relevant for a particular computation, that is the ideathat comp does not entail what I call "the 323 principle". But asStathis Papaioannou said, this does introduce a magic (non Turingemulable) role for matter in the computation, and that's againstthe comp hypothesis. No one seems to take the idea that comp doesnot entail 323 seriously in this list, but I am willing to clarifythis.Could you elaborate on the 323 principle?With pleasure. Asap.It sounds like a qualm that I also have had, to an extent, with theMGA and also with Tim Maudlin's argument against supervenience --the notion of "inertness" or "physical inactivity" seems to befairly vague.I will explain why you can deduce something precise despite thevagueness of that notion. In fact that vagueness is more a problemfro a materialist than an immaterialist in fine.How so?

`With comp, if you want introduce a physical supervenience thesis, the`

`physical activity can only mean "physical activity relevant with the`

`computation". So we can say that a physical piece of a computer is`

`inert relatively to a set S of computations in case the computations`

`in S are exactly executed with and without the physical piece.`

`Digitalness makes the notion of exactness here sense full. If someone`

`says that such a piece of matter has still some physical activity`

`involved in the computation, it can only mean that we have not chosen`

`the right level of implementation of those computations. If a`

`materialist can convince someone that such a piece, which has no role`

`for the computation in S, has some role, for S bearing a first person`

`perspective, then we can no more say "yes" to a doctor, in virtue of`

`building a device which will emulate correctly the computations in S`

`(assuming some of them corresponds to a conscious experience).`

Indeed, it is not yet entirely clear for me if comp implies 323*logically*, due to the ambiguity of the "qua computatio". In theworst case, I can put 323 in the defining hypothesis of comp, butmost of my student, and the reaction on this in the everything listsuggests it is not necessary. It just shows how far some people aretaken to avoid the conclusion by making matter and mind quitemagical.I think it is better to study the UDA1-7, before MGA, and if youwant I can answer publicly the remarks by Delahaye, both on UDA andMGA.I feel quite confident with both the UDA and the MGA (It took me alittle while).Nice.I read sane04, and quite a few old Everything discussions,including the link you gave for the MGA as well as the other postsfor MGA 2 and 3.I might send him a mail so that he can participate. Note that thetwo PDF does not address the mathematical and main part of thethesis (AUDA).So ask any question, and if Delahaye's texts suggest some one toyou, that is all good for our discussion here.My main question here would be: when Delahaye says you can't(necessarily) have probabilities for indeterministic events, isthat true?Simplifying things a little bit I do agree with that statement.There are many ways to handle indeterminacies and uncertainty.Probability measure are just a particular case. But UDA does notrely at all on probability. All what matters to understand thatphysics become a branch of arithmetic/computer science is thatwhatever means you can use to quantify the first personindeterminacy, those quantification will not change when youintroduce the delays of reconstitution, the shift real/virtual, etc.Formally, the math excludes already probability in favor ofcredibility measure. But for the simplicity of the explanation, Iuse often probability for some precise protocol. The p = 1/2 forsimple duplication is reasonable from the numerical identity ofreconstituted observers. We have a symmetry which cannot be hopedfor any coins!Credibility measure? What's that?

`Let T be a finite set, and 2^T its power set. A belief function b is a`

`function from 2^T to [0, 1] quite comparable to a probability`

`function. We have for example that b({ }) = 0, and b(T) = 1. The main`

`difference is we don't ask for the Poincare identity, we ask only for`

`an inequality:`

if Ai are subsets of T, we ask that

`b(A1 U A2 U ... U An) bigger or equal than Sum_i b(Ai) - Sum_i < j`

`b(Ai inter Aj) + ...`

`For probability we ask an equality. I see that in english they use`

`"belief", but in french we use "croyance" (credibility).`

`This leads to a variant of probability calculus which can handle`

`better the notion of ignorance than the bayesian approach.`

You might Google on "Dempster Shafer theory of evidence".

`Modal logics can be used to formalize the "certainty" case. Alechina,`

`in Amsterdam, has shown that the normal modal logic K + the formula D`

`(Bp -> Dp) formalizes this "certainty" completely, and we get`

`something similar in the relevant variants of the self-reference`

`logics. (B = [ ], D = < >), except that we loose the modal`

`necessitation rule, like for the quantum logics.`

`This is just one example of a calculus of uncertainty (apart from`

`probability). There are theories of possibility, of plausibility, etc.`

`Dempster-Shafer theory of evidence got some success in criminal`

`inquests, medical diagnostic, finding location of secret submarines,`

`debugging and inductive inference. It is particularly useful when we`

`don't want to ascribe a uniform probability in case of ignorance,`

`which is the case when we ignore the content of the set T, that is`

`when we have only partial knowledge on the elementary results of the`

`random experiences. It works also better on vague or fuzzy sets. I am`

`not an expert in that field, but my late director thesis, Philippe`

`Smets, the founder of IRIDIA, was working on an extension of such a`

`belief function theory (or theory of evidence).`

How would it affect the first few steps of the UDA if there were nodefined probability for arriving in, say, Washington vs Moscow?Well, in that case, there are probability measure. In the infiniteself-duplication, you can even use the usual gaussian. But even ifthere were no such distribution, the result remains unchanged:physics becomes a calculus of first person uncertainty with orwithout probability. As I said, only the invariance of thatuncertainty calculus matter for the proof of the reversal.Tell me if this answer your question. That seems to make sense. Thanks

`OK. Ask any question in case you want grasp completely, or who knows,`

`refute, the UDA argument. Please, for the step 8, MGA, use the most`

`recent version which exists only on this list:`

http://old.nabble.com/MGA-1-td20566948.html 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.