Bruno Marchal wrote: > > Le 26-avr.-07, à 16:31, Juergen Schmidhuber a écrit : > > > >> Hi Max, >> >> in this particular universe it's going well, thank you! >> >> As promised, I had a look at your paper. I think >> it is well written and fun to read. I've got a few comments >> though, mostly on the nature of math vs computation, >> and why Goedel is sexy but not an issue >> when it comes to identifying possible mathematical >> structures / universes / formally describable things. >> I think some of the comments are serious enough to affect >> the conclusions. Some come with quotes from papers in >> http://www.idsia.ch/~juergen/computeruniverse.html >> where several of your main issues are addressed. >> Some are marked by "Serious". >> >> I am making a cc to the everythingers, although it seems >> they are mostly interested in other things now - probably >> nobody is really going to read this tedious response which >> became much longer than I anticipated. > > > > > Don't worry, we are used to some long posts in this list. I am not sure > you follow the list because the "other things" you are mentioning are > just the follow up of the search of the theory of everything, except > that since you leave the list, denying the 1-3 distinction, some years > ago, most people who continue the discussion now are aware of the > necessity to take into account that distinction between first and third > person points of view, and more generally they are aware of the mind > body problem (or of the 1-person/3-person pov relations). I think most > of them, except new beginners, have no more any trouble with the first > person indeterminacy in self-duplication experiments, etc. > > I have already made this clear: the hypothesis that there is a physical > computable universe (physicalist-comp) is just untenable. > Let me recall you the reason: obviously physicalist-comp entails what > we are calling comp in this list, that is, the hypothesis that "we" are > locally emulable by a digital universal machine. I will call it > "indexical comp" to insist on the difference. So: > > PHYSICALIST-COMP => INDEXICAL-COMP > > > Then the Universal Dovetailer Argument shows that comp entails that > the physical appearances have to be justified *exclusively* by a > self-duplication like first person (plural) indeterminacy: see the pdf: > http://iridia.ulb.ac.be/~marchal/publications/SANE2004MARCHAL.pdf > > The main idea is that INDEXICAL-COMP entails that we don't know which > computations support our local states, and that they are a continuum of > computational histories (computations + possible "real" oracles) going > through those states.
Exactly how do you mean "continuum"? Do you mean an uncountably infinite number (the power set of the integers)? Is it a realized infinity or a potential one? >It can be argued that the first person "physical" > appearances does emerge from a "sum" on all those computational > histories, but only *as seen from those 1-person views*. But this > entails that "apparent physical universe" are not necessarily > computable objects. Actually, indexical comp entails it exists > "exploitable" internal indeterminacies. A priori: > > INDEXICAL-COMP entails NOT PHYSICALIST-COMP. > > It gives to physics a more key role than in Tegmark's idea that the > physical universe is a mathematical structure of a certain type. Comp > (indexical comp) relate somehow physics to almost all mathematical > structures (in a certain sense). > > > This constitutes the main critic of both your approach and Tegmark's > one in the search of a TOE. You still talk like if the mind body > relation was a one-one relation, when the mind can only be associated > to infinities of states/worlds. With indexical-comp there is no obvious > notion of "belonging to an universe". This has been discussed many > times on the list with different people. > > > And then, once you realize the fundamental importance, assuming comp, > of keeping distinct the possible views that a machine has to have about > arithmetical or mathematical reality, What is a machine? Am I to think of it as one of the continuum of histories corresponding to a 1st person viewpoint? Brent Meeker > and that physics emerges from one > such points of view, then it is hard not to take into account the fact > that any universal machine looking inward cannot not discover those > points of view; indeed they appear as inevitable modal or intensional > variant of the godelian provability predicate. This makes Godel's > theorems (and Lob's generalization, and then Solovay's one) key tools > for extracting physicalness from number's extensions and their (lobian) > intensions. And, and this is a major technical point, it makes this > form of comp testable, by comparing the comp-physics with the empirical > physics. > > Now I have discovered that those modal variant offer a transparent > arithmetical interpretation of Plotinus hypostases. You are welcome in > Siena in June where I will present my paper "A purely Arithmetical, yet > empirically falsifiable, Interpretation of Plotinus' Theory of Matter": > > http://www.amsta.leeds.ac.uk/~pmt6sbc/cie07.html > > I can send you a copy of the paper later for copyright reason. You can > also consult my preceding paper: > Marchal, B., Theoretical Computer Science & the Natural Sciences, > Physics of Life Reviews, Elsevier, Vol 2/4 pp 251-289, 2005. Available > here: > http://linkinghub.elsevier.com/retrieve/pii/S1571064505000242 > > > > Max, Juergen, you are still under the Aristotelian physicalist spell, > and you are still putting the "mind-body" problem under the rug, I'm > afraid. But I am aware it is a tradition since about 1500 years, when > scientists, without much choice alas, did abandon theology to > "politicians" ... > (scientific theology = theology done with the usual doubting procedure > of the modest interrogating scientist). > > > Juergen, are you still denying the 1-3 distinction (like in our old > conversations)? Are you still thinking that there is no 1-first > person indeterminacy, or that such an indeterminacy has no role in the > emergence of the physical laws? Could you tell me at which step of the > UDA you are stuck? (cf the UDA version of the SANE paper, ref above). > > I will asap try to explain the arithmetical version of the UDA, the one > based on Godel and which can be seen as an arithmetical interpretation > of Plotinus' main "hypostasis" (in case you prefer to read Plotinus > instead of doing the duplication thought experiment, UDA, ...). > Some people asks me to do this without too much technics and I have to > think about how to do that. I recall the UDA is already the "non > technical" (yet rigorous) argument. The interview of the machine is of > course formal and technical, and its only need (beside illustrating the > UDA) comes from the desire to *explicitly*extracts the physical from > numbers. > > Bruno > > PS This list, wisely unmoderated by Wei Dai, welcomes, for obvious > reason giving the hardness and originality of the subject, both > professional and non professional. By professional I just mean people > submitting theses, papers or books from time to time, even rarely. So, > don't hesitate to send us "call of paper" related with comp and or > everything-like or Everett-like TOEs. Thanks. And don't hesitate to > participate, 'course! > > > 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 [EMAIL PROTECTED] To unsubscribe from this group, send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/everything-list?hl=en -~----------~----~----~----~------~----~------~--~---