On 03 Jan 2010, at 12:05, Stathis Papaioannou wrote: > 2010/1/3 Nick Prince <[email protected]>: >> HI Bruno >> Thank you so much for your answers to my queries so far. I really >> need to do some more thinking about all that you have said so far and >> to understand why I am having difficulty replacing a real physical >> universal machine existing in the future (like Tipler suggests) or a >> great programmer existing now (like schmidhuber suggests) with your >> arithmetical realism. I also need to search some previous posts to >> make use of past discussion topics that are relevant. Perhaps my >> background makes me a physicalist who can currently accept a milder >> form of comp. However, I want to explore your position because I >> think it makes sense in so far as I think it is less vulnerable to >> the >> threat of infinite regressions like in Schmidhuber’s great >> programmer >> (or even the greater programmer that programmed him). Your version >> of >> computationalism would still be valid if either or both of the two >> options above were true. Herein lies its appeal to me (both >> fundamental and universal). >> I would like to read up on logic and computation as you suggest. I >> have read about all the books you recommend . However, can you >> suggest >> topic areas within these texts which I can focus on to help me get >> up >> to speed with the problems I have regarding arithmetical realism with >> the UDA? There is much that could perhaps be left out on a first >> reading and to my untrained eyes, it’s difficult to know what to omit >> (for example what would godels arithmetisation technique come under? >> (Googling it brings not much up). Sorry but I haven’t ordered any >> books yet so I can’t look into them. >> Is there an English translation of your Ph.D. thesis yet? Sorry >> but I >> can’t do French. My thanks and best wishes. > > My justification for the hardwareless computer is the fact that any > computation can be mapped onto any physical process, in the same way > that any English sentence can be mapped onto any string of symbols.
You should elaborate and be more precise. Ho do you map the English sentence "Life what is it but a dream" onto the string "xxx"? How do you map the computation of the decimal of PI on *any* physical process. It is true that once we understand that any piece of matter is somehow the result of an infinity of competing universal machine, then you are right: if the quantum or comp vacuum can be said to compute anything, but not in the "doctor" sense: of saying "yes" for a relative substitution. > Such a post hoc mapping would be useless to an observer trying to > extract meaning from the symbols or the result of a calculation from > the computer, since he would have to figure out the mapping himself > and he would have to know the answer he wants before doing this. I mainly agree. the computation define the interpreter/observer, and there is no need to interpret the interpreter. He does it by itself very well (assuming comp). > With > the right key Bruno's PhD thesis contains an account of next week's > news, but so what? Such a key to make sense has to be universal. If you change the key often, you encode the computation in an arbitrary string together with a non arbitrary sequence of key. Computation makes sense only because e choose once and for all any arbitrary key, and don't change it anymore. The basic key is the given of elementary arithmetical axioms. > If you look at it the right way the dust swept up > by a storm is implementing a Turing machine calculating the digits of > pi, I don't believe this. To interpret the dust move as a computation of PI, you will have to generate a complex sequence of keys. The computation of PI will be hidden in the generation of the sequence of key, not in the dust move. > but what good does that do anyone? The claim that codes and > computations lurk hidden all around us could be taken as true but > trivial, or perhaps defined away as untrue on account of its > triviality. However, there is a special class of computations to > consider: computations that give rise to conscious observers in > virtual universes that do not interact with the environment at the > level of the substrate of implementation. If such computations are > possible (i.e. if comp is true) then it doesn't matter that no > external observers have access to the mapping that would allow them to > recognise them, for these computations create their own observers, > bootstrapping themselves into non-triviality. That is right. Once number relations describe a computation, we can ascribe consciousness to it, if the computation describe some interpreters. This includes the key. But the dust doesn't do that, except in the comp sense that dust itself is a sump on an infinity of computations. The dust don't do the computations without the keys. Except in the lucky "white rabbit" case where it does, for some unknown fixed case, but the probability of this happening, is 1/10^(very big number). That is why no one will say yes to a doctor who propose to you to replace your brain by dust. > The physical process > "sustaining" the computation need not even be as complex in structure > as the computation: the computation could be mapped for example onto a > repetitive process, the idle passage of time, even a single instant of > time implementing the parts of the computation in parallel. I can give sense to this, but it is misleading imo. > And if we > get that far, it's obvious that the physical process does nothing, and > we may as well map the computation onto the null set. It is obvious > that the entire structure of the computation is contained in the > mapping, and the mapping is a platonic object, not dependent on being > written down or even understood in the mind of an external observer. I agree again. The mapping, including the key, as to be done by a universal number/computer, and exists independently of matter. Remember that even the movie of a computation does not compute despite the existence of a (physical) mapping. Arbitrarily complex mapping always exists, but computation exists only in the abstract mapping, so that the sequence of key have to be related to a genuine computation (in the math sense). Then complex arbitrary mapping just become relatively rare, and will correspond to white rabbit realities, except that here those white rabbit realities are faking "normal computations". You may read the papers of Bennett on depth of computation. A computation, or a computable mapping is quite different from arbitrary mapping. Only the computable one makes sense and can produce consciousness. From our first person perspective, the non computable mapping will just add a level of noise, for the statistical/measure reason. A brain really interprets itself, the key is in the universal interpreter it realizes. You cannot change the key aribtrarily, you have at least to be able to generate the sequence of key changes on a "universal" base (like arithmetic, combinators, etc.). 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 [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.
