Bruno Marchal wrote: > On 30 Apr 2009, at 15:49, Stathis Papaioannou wrote: > > >> 2009/4/30 Bruno Marchal <marc...@ulb.ac.be>: >> >> >>>> Putnam and Searle use the Rock argument to suggest >>>> that computationalism is false: they consider it absurd that any >>>> conscious computation supervenes on any physical activity (or >>>> equivalently no physical activity, since at one extreme the Rock >>>> argument allows that any computation is implemented by the null >>>> state). >>>> >>> ? >>> >> If the vibration of atoms in a rock can be mapped onto any >> computation, then there is a one to many relationship between a >> physical state and a computation. >> > > > But why and how should the vibration of atoms in a rock be mappable > onto any computations? > Accepting QM I can see one quantum computation: the simulation of the > rock. > Computation are global things. It is not the union of a lot of tiny > computations, it is the union of those tiny computations + the > universal state which unite them. (and then from inside the problem is > that there are an infinity of them). > > > > > > >> That is, you can't say that the rock >> implements one computation but not another. >> > > I don't think it implements any computations. I could accept some tiny > apparition of tiny pieces of of tiny automata, but nothing big or > sophisticated. Some very special crystals perhaps, no doubt, but those > are, then, computer. > > > > >> So the rock is a massively >> parallel computer implementing every computation. >> > > > No, a finite rock goes in cycle and does not makes any long > computation, still less the deep one. It does at most some > computational noise. Computation, like brain are relatively rare in > the universe. If Hubble detect a computation somewhere, iy will be > taken as an argument for the presence of intelligent beings there. But > it hasn't. > The genome of a bacteria implements very simple form of computations. > There are IF ... THEN... ELSE, loops, and conditionnal (by regulatory > gene). But it took billions of year to "nature" to make them appear. > Just show me the computation of factorial(24) in a rock. No one has > shown that. > > > > >> Furthermore, any >> subset (in time and space) of the rock is a massively parallel >> computer implementing any computation. >> > > > This is probably true for something like the border of the Mandelbrot > set. But there is no concrete mandelbrot set in nature. > > > > >> At the limit, a minimal subset >> of the rock, such as a quark existing for one Planck interval, >> implements every computation. >> > > Hard for me to think you are serious here. A case can be made that the > quantum vacuum is Turing universal, but this makes him doing > "sophisticated" computation relatively to us, only ... in the quantum > white rabbit universes. > > > > > >> And why not go one step further and say >> that nothingness implements every computation? >> > > > If you stay with a physical realm, you will get only physical > nothingness, which even in classical physics is not nothingness. > > > > >> So you arrive at the >> conclusion, computation exists independently of physical activity. >> > > That would please me, but I don't see at all the logic. > > > > >> Few >> people seem satisfied with this conclusion, so they try to argue >> either that computationalism is false >> > > > A lot of people try to argue that computationalism is false, and > usually the argument can be shown directly non valid; Searles for > example mixes levels of description (as Dennett and Hofstadter show > very well in Mind'sI). > Other have better argument, like Maudlin, but this shows only that > comp is not compatible with linking computation with the running of > one universal machine, or worse with the only physical one. It is more > interesting because it shows the real difficulty of the mind-body > problem once we take comp seriously. > But remember Jacques Mallah. He shows that there is an implementation > problem (with physicalism). Along those line a physicalist could > affirm that even a running computer does not run a "mathematical > computation". Unfortunately for Mallah, such a problem dissolves when > you understand that the physical world is not a primitive reality, but > something which emerge from the logical relations among numbers. > Indeed, through the "eyes" of the universal machines/numbers. > Arithmetical reality or alike are the only realms where computations > exists and are well defined. > > > > >> or else that computationalism is >> true and dependent on physical activity >> > > Which is false by UDA+MGA. > > > > > >> and therefore that the >> argument is invalid. >> > > > That is weird. > > I think that you believe that a rock implements computations, because > you believe a computation can be decomposed in tiny computations, but > this is not true, you need much more. You need a universal machine > which links and complexify the states in a precise way. > Some alive beings do some computations (like some flowers compute tiny > part of the Fibonacci function). But again, this is sophisticated and > took time to appear. Waves do analog computations, hardly universal > digital one, or only when put in some very special condition. > Interesting and rich computations are relatively rare and exceptional > until they self-multiplied, like amoebas. > Does the universe compute its states? How is the evolution of the wave function of the universe or of a flower not a computation?
> Nor do I believe the filmed movie graph do any computation, it "read" > a description of one, but does not link them logically in real time. > Today, genetical systems, brains, and computer (human or engineered) > do "concrete" computations. > But that seems like introducing a "magic" similar to the magic of physical existence, except now it is the magic of computational connection. Brent > The mathematical Universal Dovetailer, the splashed universal Turing > Machine, the rational Mandelbrot set, or any creative sets in the > sense of Emil Post, does all computations. Really all, with Church > thesis. This is a theorem in math. The rock? Show me just the 30 first > steps of a computation of square-root(2). > Robinson Arithmetic, Peano Arithmetic, Zermelo Fraenkel Set theory and > many theories compute, notably, all computations, through the > enumeration of the proof of all the True Sigma_1 arithmetical > sentences, but they do much more, they reason and prove more complex > propositions about them (Lobian Machine). > > But again, even if rocks implements computations, this changes nothing > to the reversal reasoning. IF rocks implements all computations, it > means the Universal measure is a tiny epsilon more complex to compute, > given that the measure is put on all possible computations. It means > we have to take into account all digital rock's state accessed by the > universal dovetailer. > > 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 -~----------~----~----~----~------~----~------~--~---
