On Wednesday, September 5, 2018 at 9:12:49 AM UTC-5, Bruno Marchal wrote: > > > On 5 Sep 2018, at 11:54, Philip Thrift <[email protected] <javascript:>> > wrote: > > > > On Wednesday, September 5, 2018 at 2:28:39 AM UTC-5, Bruno Marchal wrote: >> >> >> On 2 Sep 2018, at 21:32, Philip Thrift <[email protected]> wrote: >> >> >> >> On Sunday, September 2, 2018 at 8:15:01 AM UTC-5, Bruno Marchal wrote: >>> >>> >>> On 30 Aug 2018, at 01:04, Philip Thrift <[email protected]> wrote: >>> >>> >>> >>> On Wednesday, August 29, 2018 at 4:55:12 PM UTC-5, Brent wrote: >>>> >>>> Do you have some evidence for doubting CT? It seems that it's >>>> essentially a definition of digital computation. So you could offer >>>> some other definition, but it would need to be realisable. >>>> >>>> Brent >>>> >>>> On 8/29/2018 12:12 PM, Philip Thrift wrote: >>>> > also thought by some in what I call the UCNC gang >>>> >>>> Also thought WHAT? >>>> >>> >>> >>> >>> >>> In terms of theory, Joel David Hamkins @*JDHamkins* >>> <https://twitter.com/JDHamkins> (the set-theorist now at Oxford) >>> considers infinite-time TMs to be a part of "computation": >>> >>> >>> http://jdh.hamkins.org/ittms/ >>> >>> If computation is the fundamental "substrate" of nature, and ITTMs are >>> "natural" extensions of TMs, there is no reason to exclude ITTMs. >>> >>> I have explained in this list, and in my papers, that Church’s thesis >>> (with Mechanism) entails that matter and nature are non computable. >>> Elementary arithmetic realise/emulate all computations, and physics is >>> reduced into a statistic on all computations, which is not something a >>> priori computable. If mechanism is refuted some day, it will be by showing >>> that nature is “too much computable”, not by showing that nature is not >>> computable. Mechanism in cognitive science is incompatible with Mechanism >>> in physics. Now, it could be that the only not computable things is just a >>> random oracle, but this does not change the class of computable function. >>> It would change the class of polynomial-time computable function, as we >>> suspect nature do, but that confirms mechanism which predicts this. >>> >>> >>> >>> >>> >>> But what does the presence of ITTMs mean for the CT thesis? Whether >>> ITTMs are "realizable" remains to be seen. >>> >>> >>> The CT thesis identifies human intuitively computable functions with >>> functions programmable on a computer. It is a priori neutral on what the >>> physical reality can compute. With mechanism, CT entails the existence of >>> non emulable phenomena by computer “in real time”. >>> >>> >>> >>> >>> In terms of practice, UCNC people think that computers made with >>> non-standard materials, e.g. "live" bioware produced by synthetic biology, >>> could have novel computational (behavioural) abilities not equivalently >>> replicable in a simulation. >>> >>> >>> Quantum computer can emulate some piece of matter more quickly than a >>> classical computer. But that was a prediction of mechanism. You can read >>> the basic explanation in my paper here if interested. >>> >>> >>> B. Marchal. The Origin of Physical Laws and Sensations. In 4th >>> International System Administration and Network Engineering Conference, >>> SANE 2004, Amsterdam, 2004. >>> >>> http://iridia.ulb.ac.be/~marchal/publications/SANE2004MARCHALAbstract.html >>> (sane04) >>> >>> >>> The key notion if the “first person indeterminacy” which is just the >>> fact that if we are machine, we are duplicable, and duplicated in >>> arithmetic, and whatever we predict about our first person experience is >>> indeterminate on the set of all computations (in arithmetic) which go >>> through our local and actual state of mind (that is: an infinity). >>> Physicalism is refuted with mechanism, and becomes a branch of machine >>> psychology, or better machine theology (the study of the non provable true >>> propositions). >>> >>> I am just know writing a post on why Church’s thesis is a quasi-miracle >>> in mathematics and epistemology. In particular it entails the >>> incompleteness phenomenon, from which we can derive mathematically the >>> physical laws. That makes Mechanism testable, and indeed, we recover >>> already the quantum logical core of the formalism. >>> >>> Bruno >>> >>> >> >> This is very interesting. (I've written about the irreducibility of >> "matter" to physics, e.g., >> [ https://codicalist.wordpress.com/2018/06/20/materialism-vs-physicalism/ >> ].) >> >> >> >> I will take a look, but feel free to explain the basic. >> >> >> >> >> >> >> Do you see what role a "multiverse perspective of mathematical truth" >> could play in your theory? >> >> https://en.wikipedia.org/wiki/Joel_David_Hamkins#Philosophy_of_set_theory >> https://arxiv.org/abs/1108.4223 >> >> >> I am not sure why you say that the the universe of set is well defined. >> To be franc, although I am realist on arithmetic, I am not for set theory, >> nor analysis, second ordre arithmetic. >> >> Most set theories that I know are first order theory, ans thus they have >> infinitely many non-isomorphic models, including enumerable one. A problem >> here is that we call set theory, well set theory or theory of sets, when we >> should say “theory of universes” (in the math sense of universes of set), >> if we use “of” like in theory of groups, or we should call “theory of >> groups” a theory of vectors, or a theory of transformation. That gives the >> feeling that set theory admit one clear model, but it has many. Arithmetic >> also has many non-isomorphic models, but most people agree on a notion of >> standard model, which lacks for set. Also, there are many set theories, >> which all have different models, but quite different theorems too. In Quine >> set theory (New Foundations, NF), the universes can belong to themselves, >> which is not the case in Zermelo-Fraekel of Von Neuman Bernays Gödel set >> theories. That is a reason why I prefer to put “set theory” in the catalog >> of the mind of the universal machine looking at itself. >> >> Once we postulate Mechanism, the “cardinality” of the mathematical >> "universe" becomes undecidable, and it is simpler to use enumerable models. >> In fact, the standard model of arithmetic is already too much big, and we >> can decide to postulate only the “sigma_1 truth”, or the “PI_1 truth”, that >> is the truth of the proposition having the shape ExP(x,y) with P decidable >> (and their negations). That is, we need only the notion of computation >> (which provably exists in any Sigma_1 complete (= Turing universal) theory. >> We do get a constructive “multiverse” of some sort, which I call Universal >> Dovetailer. It is a program which generates all programs, and executes them >> all, in a dovetailed way, pieces by pieces to avoid being stuck in non >> terminating computations (something that I have just explained to be non >> predictable in advance). From this I have extracted the mathematics of a >> physical multiverse, but that structure is phenomenological: it exist only >> in the mind of the machines (naturally implemented in arithmetic). Physics >> becomes a statistics on computations, and the math fit well with some >> version of Quantum Mechanics, until now. >> >> More on this later, very plausibly. >> >> Bruno >> >> >> > On the reduction of all matter to physics: > > I consider "all matter" to include everything studied by natural sciences: > physics, chemistry, biology, etc. I cite in some of my Notes* the concept > that there may be "laws" of chemistry (or biology) that cannot be "reduced" > to "laws" of physics. > > * e.g. 87. Backward and Downward! > https://codicalist.wordpress.com/2018/07/06/backward-and-downward/ > (the references there to "downward causation") > > There is another term: Incommensurability of the sciences > https://plato.stanford.edu/entries/incommensurability/ > > http://depa.fquim.unam.mx/sieq/Documentos/floresgallegosgarritzgarciaincommensurabilityse2007.pdf > > The idea is that the spectrum of matter (from particles to people) has a > spectrum of laws. > > > On a (computational) universal dovetailer and its relationship to > conscious matter: worth finding out more. > > > > I can explain that IF we assume that the brain or the body is Turing > emulable, then everything can be reduced to arithmetic. Note that > arithmetic is not a computable thing (the computable part of arithmetic is > a very tiny part of arithmetic). It makes machine theology becoming the > fundamental science. In particular physics and the natural science get > reduced to “machine theology”, and this has been proven constructively: so > that physics is deducible from arithmetical self-reference. That makes > mechanism testable by comparing the physics deducible from theology with > the physics inferred from observation. This works (until now), where > physicalism does not work (as most people grasping the mind)body problem > are more or less aware since long). > > I can agree that there is a spectrum of laws, that is the natural case in > computer science. To understand a brain by studying neurons cannot work. It > would be like trying to understand Big Blue strategy to win Chess game by > studying the electronic gates. That might explain how some strategy is > implemented, but that will not put light on which strategy is used. > > I am skeptical on (primary) matter. That is not used in physics, only in > metaphysics, and its use is more like the use of God in some theologies: to > prevent the search of theories and make people stopping asking question. > > What is matter? If I may ask? What are your evidence for all is matter? > And are you open to the mechanist theory of mind? (The idea that there is > no magic operating in a brain, or the idea that we could survive with a > digital brain transplant, obtained by copying it at some level of > description). Mechanism is my working hypothesis, and it makes primary > matter very doubtful. We get a simpler explanation of both mind and > matter-appearances without it, as matter, nor a god, can select a > computation in arithmetic. > > The notion of computation is a purely mathematical (arithmetical) notion. > It should not be confused with the notion of physical computation, which > will appear to be a very special case, observable by the average universal > (digital) machine/number from inside arithmetic. > > Bruno > >
I have mainly followed the perspective of the late Turing scholar S. Barry Cooper [ https://en.wikipedia.org/wiki/S._Barry_Cooper ]: *Incomputability after Alan Turing* [ https://arxiv.org/abs/1304.6363 ] Basically: We don't know the full nature of physical [ that is, material ] computation. Corollary: We don't know the full nature of matter. Computation without matter, even though we don't know completely what matter is (like Kant's noumenon) remains a ghostly entity, one where there is no real experientiality (like the pleasure of eating a candy bar). - Philip Thrift -- You received this message because you are subscribed to the Google Groups "Everything List" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To post to this group, send email to [email protected]. Visit this group at https://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/d/optout.
