I'm confused about the universe expanding faster than light speed. Anyone care to explain or cite a ref? Thanks, m.a.
On Thu, Sep 6, 2018 at 4:01 PM Philip Thrift <[email protected]> wrote: > > > On Thursday, September 6, 2018 at 2:48:53 PM UTC-5, Philip Thrift wrote: >> >> >> >> On Thursday, September 6, 2018 at 11:47:46 AM UTC-5, Bruno Marchal wrote: >>> >>> >>> On 6 Sep 2018, at 17:04, Philip Thrift <[email protected]> wrote: >>> >>> >>> >>> On Thursday, September 6, 2018 at 4:23:23 AM UTC-5, Bruno Marchal wrote: >>>> >>>> >>>> On 5 Sep 2018, at 18:58, Philip Thrift <[email protected]> wrote: >>>> >>>> >>>> >>>> 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]> 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 ] >>>> >>>> >>>> I appreciate very much Barry Cooper. He invited me at one of the >>>> European Meeting on Computability (CiE). >>>> It is there that I prenseted my Plotinus paper (accessible on my URL >>>> frontage). >>>> >>>> >>>> >>>> >>>> Basically: We don't know the full nature of physical [ that is, >>>> material ] computation. >>>> >>>> >>>> OK. But Feynman and Dutch, like Landauer and Bekenstein did great >>>> advances. Of course many great questions remain unsolved. >>>> >>>> >>>> >>>> Corollary: We don't know the full nature of matter. >>>> >>>> >>>> I can explain in all details that “matter” (in its usual occidental >>>> sense of primary substance) does not make sense once we postulate (Digital) >>>> Mechanism. To put it simply: matter do not exist. There is no physical >>>> universe, … or Mechanism is false, but there are no evidence for that. On >>>> the contrary, modern physics sides more and more with the immaterialist >>>> theology/metaphysics. The more we observe nature, the more we guess the >>>> deep mathematical reality at its origin. >>>> >>>> >>>> >>>> >>>> >>>> Computation without matter, even though we don't know completely what >>>> matter is (like Kant's noumenon) remains a ghostly entity, >>>> >>>> >>>> Here I disagree. Unless you mean that 2+2=4 is a ghostly truth (in >>>> which case I invite you to convince my taxe inspector! >>>> The (arithmetical) notion of computation is a astonishingly clear >>>> mathematical notion thanks to Church thesis. It admit an infinity of >>>> apparently very different definitions, yet they can be shown equivalent, >>>> and indeed equivalent to very simple definition of them, like I illustrate >>>> with the combinators. It is a unique fact in the history of mathematics: an >>>> epistemological (computable) notion which get a precise mathematical (even >>>> arithmetical) definition. I am as sure about the existence of computations >>>> than I am about the existence of prime numbers. I am less sure of >>>> Mechanism, but then that is why I proposed an experimental testing >>>> procedure, and as I said, physics confirms Mechanism (up to now at least, >>>> thanks mainly to quantum-mechanics-without-collapse). >>>> >>>> >>>> >>>> >>>> one where there is no real experientiality (like the pleasure of eating >>>> a candy bar). >>>> >>>> >>>> On the contrary, the logic of self-reference explains both qualia and >>>> quanta, and link them without using the brain-mind identity thesis, which >>>> has been debunked in the frame of Mechanism. Why would there be no real >>>> experience, and how could you know that? Yet, your position might be >>>> coherent: if matter exist and play a role in consciousness, then we cannot >>>> be digital machine, and there must be actual infinities in nature. But that >>>> seems rather speculative, given the absence of evidence for both actual >>>> infinite in Nature, and the evidences for mechanism (Darwin theory of >>>> evolution uses mechanism quasi explicitly, for example). >>>> >>>> So, you would not accept a digital brain transplant (in theory, in >>>> practice me too!). That seems to me like invoking something more complex >>>> that what we want to explain, to avoid searching an explanation. Matter is >>>> a speculative hypothesis in metaphysics without evidences, and which hides >>>> more the problem than clarifying it, I think. I prefer to assume Mechanism, >>>> and see if we are lead to absurdity or to facts contradicted by nature. But >>>> the most startling fact predicted by Mechanim, —the fact that physics is a >>>> statistic on many computations is somehow confirmed by Quantum Mechanics >>>> (without collapse). Then it took me 30 years to confirms this >>>> mathematically (using the self-reference logics of Gödel, Löb and Solovay). >>>> >>>> Bruno. >>>> >>>> >>>> >>> >>> My own (hypothetical) course in Philosophy of Mathematics would begin >>> with this slide: >>> >>> *"There are no such things as mathematical objects.”* >>> >>> >>> >>> With mechanism, we are mathematical object, and the physical reality is >>> a mathematical phenomenon, so there is no physical object per se. That does >>> not threat the existence of the moon, of galaxies, or bosons and fermions, >>> but such existence becomes phenomenological, yet more universal in the >>> sense that the core of the physical laws is the same for all universal >>> machine, the rest becomes historico-geographical differentiations. >>> Mechanism makes it possible to delineate the indexical geography from what >>> are genuinely univarsable laws for the universal machine observable. >>> >>> >>> >>> >>> >>> >>> cf. https://twitter.com/philipthrift/status/1029079439190228992 >>> *Mathematical pulp fictionalism* [ >>> https://codicalist.wordpress.com/2018/08/26/mathematical-pulp-fictionalism/ >>> ] >>> ref: https://plato.stanford.edu/entries/fictionalism-mathematics/ >>> >>> That being the first principle, I would say what does exist are material >>> objects. And then proceed from there. >>> >>> >>> You will have to say “no” to the doctor proposing you a digital brain >>> transplant. If we survive such transplants, we survive in the infinitely >>> many continuations that are emulated in arithmetic, and the laws of physics >>> are determined by what is provable in all such continuations, which is >>> then mathematically recovered by nuances on provability logic imposed by >>> incompleteness. It works actually, until now, formally, and intuitively if >>> you agree with QM-without collapse. >>> >>> I avoid as much as possible to use any hypothesis in philosophy of >>> mathematics, as the Mechanist Hypothesis in ogive science is so strong as >>> to reset what we can sought on this. Contrary to what many people think, >>> Mechanism is incompatible with Materialism. It explains the observable >>> without any ontological commitment other than what is needed to define the >>> notion of computation (and this requires nothing more than what is required >>> in elementary arithmetic, or combinator theory, or anything equivalent with >>> respect to computability). >>> >>> It uses only arithmetical realism, and recently I have discovered that >>> it works even with some form of ultrafinitism. My “theory” seems to be the >>> common base of all possible theories. A non arithmetical realist is someone >>> who disbelieve that it is false that a digital machine stops or not. >>> >>> I doubt less 2+2=4 than F=ma or the SWE, or the existence of the moon, >>> or my body, which are among what I try to explain from simple things, like >>> "x+2 = 9 has a solution”. >>> >>> When you say “there is no mathematical object?” What do you mean. Please >>> make your point here, and refers only for more detailed and lengthy >>> treatment. To me, even without Mechanism, it seems that the notion of >>> physical object is far less clear than mathematical object. I am not sure >>> modern physics can define what is a physical object: you need a “theory of >>> everything physical” for that, but gravitation and the quantum makes the >>> big picture still not accessible. Mechanism does not (yet) seem to imply >>> that the physical reality is, or not, immune to diagonalisation, so some >>> universal number can still play some role in the physical reality, but we >>> are far to know that, and the theory would still be a description of number >>> relations. With mechanism, we can associate minds only to infinities of >>> computations. Assuming physical object gives them a magical ability to >>> deflect your consciousness in arithmetic, in a way which is not explainable >>> when we assume Mechanism. >>> >>> Just to say that at some point you will need some non mechanist theory >>> of mind, if you really want to have physicalist primary objects. Of course, >>> I will also ask you some theory about those objects. >>> >>> Assuming Matter is a bit like assuming God. I can accept that things >>> like that exists phenomenologically, and perhaps ontologically. But even in >>> that case, invoking them does not help to explain them. I prefer to start >>> from what I am the closest to certainty, like 2+2=4, or SKKK = K. >>> >>> Bruno >>> >>> >>> >> >> By *"There are no such things as mathematical objects”* (quoted from >> the SEP article "Fictionalism in the Philosophy of Mathematics") I mean >> that in the language(s) of mathematics (including arithmetic), the objects >> referred to are fictional and do not exist; as in vampire stories, the >> vampire is a fictional object that does not exist. So the 2 in "2+2=4" is a >> fictional object: it does not exist. >> >> - Philip Thrift >> > > On "digital machines", of course all material machines have to stop > operation eventually given that this universe won't go on forever (unless > "fictional" black hole computers are possible). > > - 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. > -- 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.
