Bruno Marchal wrote: > I answer you, but it is at the same time a test, because most of my > yesterday (sunday 22 october) posts seems not having been send > successfully. > (Some arrived at the archive, but not in my mail box, others nowhere, I > will wait a whole and resend them: it was message for Peter and David).

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Bruno, I think it's the Beta version that's intermittently losing posts - Colin lost one, and I've lost two. I've posted a topic to this effect for the list. You may wish to revert to the old version. David > Hi Stathis, > > I answer you, but it is at the same time a test, because most of my > yesterday (sunday 22 october) posts seems not having been send > successfully. > (Some arrived at the archive, but not in my mail box, others nowhere, I > will wait a whole and resend them: it was message for Peter and David). > > Le 23-oct.-06, à 04:35, Stathis Papaioannou a écrit : > > > > > >> Church thesis just assert that a universal turing machine can compute > >> all computable functions from N to N. > >> It relate a mathematical object with a human cognitive notion. It does > >> not invoke physical machine at all. > > > > In a sense that is true, but a TM is still a model of what could > > possibly be built > > in a physical universe such as ours. Of course the model is still > > valid irrespective > > of the existence of a physical machine or indeed a physical universe, > > but if you > > abandon the idea of a physical universe there is no need to constrain > > yourself to > > models based on one. > > I am not sure why you say the TM model is based on what we can build in > the physical universe. > Both with comp and without, the physical universe is a priori far > richer than a UTM. > The UTM of Turing relies explicitly on an analysis of human capacity > for computations. > Post universal systems are based on analysis of mathematician > psychology. > > > > > So I suppose the two questions I have (which you partly > > answer below) are, having arrived at step 8 of the UDA could you go > > back and > > say that the UD is not really necessary but all the required > > computations exist > > eternally without any generating mechanism or program (after all, you > > make this > > assumption for the UD itself), or alternatively, could you have > > started with step > > 8 and eliminate the need for the UD in the argument at all? > > > This is the way I proceed in "Conscience and Mechanism". I begin, by > using the movie graph argument MGA, to show that consciousness cannot > be attached to physical activities, and then I use the UD to explain > that the comp-physics get the form of a measure on all computations. > In my Lille thesis I do the opposite because the UDA is simpler than > the MGA. It is not so important. > UD is needed to justify and to make mathematically precise the ontic > 3-observer moments. They correspond to its (the UD) accessible states. > > > > > > >>> It seems that this is the computer you > >>> have in mind to run the UD. > >> > >> Only for providing a decor for a story. This assumption is eliminated > >> when we arrive (step eight of UDA-8) at the conclusion that universal > >> digital machine cannot distinguish any "reality" from an arithmetical > >> one. > >> > >> > >>> That's OK and the argument works (assuming > >>> comp etc.), but in Platonia you have access to hypercomputers of the > >>> best > >>> and fastest kind. > >> > >> Fastness is relative in Platonia. Universal machine can always been > >> sped up on almost all their inputs (There is a theorem by Blum and > >> Marquez to that effect). Then indeed there are the "angels" and > >> hierachies of "non-comp" machine. A vast category of "angels" can be > >> shown to have the same hypostases (so we cannot tested by empirical > >> means if we are such angels). Then they are entities very closed to > >> the > >> "one", having stronger hypostases, i.e. you need to add axioms to G > >> and > >> G* (or V, V* with explicit comp) to get them. > > > > Of course I was joking when I said "best and fastest". In Platonia > > there is > > no actual time and everything is as fast and as perfect as you want it. > > OK. But of course there exist notion of relative time: a fast Fourier > transform is faster than a slow Fourier transform, even in Platonia. Of > course this can be said in term of number of steps in computations (no > need to invoke time). > > 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 [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/everything-list -~----------~----~----~----~------~----~------~--~---