On Mon, May 13, 2019 at 7:45 AM Bruce Kellett <[email protected]> wrote:
> On Mon, May 13, 2019 at 5:42 PM Jason Resch <[email protected]> wrote: > >> On Mon, May 13, 2019 at 1:20 AM Bruce Kellett <[email protected]> >> wrote: >> >>> On Mon, May 13, 2019 at 3:49 PM Jason Resch <[email protected]> >>> wrote: >>> >>>> On Sun, May 12, 2019 at 11:20 PM Bruce Kellett <[email protected]> >>>> wrote: >>>> >>>>> On Mon, May 13, 2019 at 2:00 PM Jason Resch <[email protected]> >>>>> wrote: >>>>> >>>>>> On Sun, May 12, 2019 at 9:52 PM Bruce Kellett <[email protected]> >>>>>> wrote: >>>>>> >>>>>>> On Mon, May 13, 2019 at 12:40 PM Jason Resch <[email protected]> >>>>>>> wrote: >>>>>>> >>>>>>>> On Sun, May 12, 2019 at 9:04 PM Bruce Kellett < >>>>>>>> [email protected]> wrote: >>>>>>>> >>>>>>>>> From: Jason Resch <[email protected]> >>>>>>>>> >>>>>>>>> On Fri, May 10, 2019 at 6:02 PM Bruce Kellett < >>>>>>>>> [email protected]> wrote: >>>>>>>>> >>>>>>>>>> On Fri, May 10, 2019 at 11:42 PM Jason Resch < >>>>>>>>>> [email protected]> wrote: >>>>>>>>>> >>>>>>>>>>> On Fri, May 10, 2019 at 8:16 AM Bruce Kellett < >>>>>>>>>>> [email protected]> wrote: >>>>>>>>>>> >>>>>>>>>>>> >>>>>>>>>>>> Then with mechanism, we get the many-histories from a simple >>>>>>>>>>>>> fact to prove: all computations are realised in all models of >>>>>>>>>>>>> arithmetic. >>>>>>>>>>>>> >>>>>>>>>>>> >>>>>>>>>>>> But arithmetic does not exist independently of the human mind, >>>>>>>>>>>> and mechanism is manifestly a pipe dream. >>>>>>>>>>>> >>>>>>>>>>>> >>>>>>>>>>> You sound certain. What is your evidence? >>>>>>>>>>> >>>>>>>>>>> Jason >>>>>>>>>>> >>>>>>>>>> >>>>>>>>>> The is no evidence for mathematical realism, >>>>>>>>>> >>>>>>>>> >>>>>>>>> There is plenty given in my other post to you. Even if there were >>>>>>>>> none, what evidence do you have against it for you to be so sure it is >>>>>>>>> false? (mathematical realism is the leading philosophy of mathematics, >>>>>>>>> among mathematicians, >>>>>>>>> >>>>>>>>> On Mondays, Wednesdays, and Fridays.The other days of the week >>>>>>>>> most mathematicians are nominalists! (And I had this from a >>>>>>>>> professional >>>>>>>>> mathematician!) >>>>>>>>> >>>>>>>> >>>>>>>> That's an anecdote, not data. >>>>>>>> >>>>>>> >>>>>>> The truth of these issues is not determined by counting heads. >>>>>>> >>>>>> >>>>>> It does not. But your conviction that Platonism is false requires >>>>>> some justification or reason, given that it would overturn a predominate >>>>>> theory in a field. >>>>>> >>>>> >>>>> No, you have to give evidence in support of platonism, given that this >>>>> view has been a philosophical failure, leading to a dead end, not a >>>>> progressive theory. >>>>> >>>> >>>> That is false. Taking the pre-existence of all conscious states (a >>>> natural consequences of Platonism) is the only theory in science I am aware >>>> of that plausibly explains why our universe has: >>>> >>>> - https://arxiv.org/pdf/1712.01826.pdf >>>> >>>> I have started to read this paper. It seems to be just another take on >>> computationalist arguments such as given by Bruno. It could be criticised >>> in detail, but the main problem I see is the rejection of scientific >>> realism at the start, and the unquestioned assumption of mathematical >>> realism. Defining 'things' by relationships loses the distinction between >>> physics and mathematics, which is the cause of all the trouble. >>> >> >>> >>>> - Simple physical laws that are probabilistic >>>> - Persistent regularities >>>> - An external world that contains the observer >>>> - Inter-subjective agreement on physical laws >>>> >>>> These are just empirical observations. We choose laws that are as >>> simple as possible to describe observations. There is nothing profound in >>> that. >>> >>> >> >> Falling apples were just empirical observations until Newton gave a >> theory that provided an account of why apples fell. >> > > No he didn't. Newton gave a theory that describes both how apples fall and > planets orbit the sun. It doesn't tell us why apples fall. Science provides > 'how' answers, not 'why' answers. Newton was very careful to point out that > he wouldn't make hypotheses beyond the observable facts -- no 'why' answers. > > >>>> - Simple initial conditions >>>> >>>> Who said the initial conditions of the universe were simple? >>> >>>> >>>> - Observation of a universe that evolves in time >>>> >>>> What is time in General relativity. It is merely a local phenomenon. >>> >>>> >>>> - Observation of a universe with an absolute beginning in time >>>> >>>> Does it? There are plenty of cosmological theories where this is not >>> the case. >>> >> >> There is a time (Big Bang) which we cannot make meaningful predictions >> about what happened before. Muller's paper goes into more details about >> what specifically an observer could predict about the beginnings of their >> universe. >> > > I am not sure I have the time to delve into Muller's paper to find out his > reasons. He is clearly misguided, because there are many viable > cosmological theories that do not have a beginning of time (such as eternal > inflation and related ideas) -- even if time is universally defined, which > is very doubtful. > To be clear, his result does not rule out inflation, he finds only that observers can expect that there we will find a beginning in history where if we try to penetrate more deeply into what happened before, it devolves into a multitude of indistinguishable possibilities. > > >> >>>> - https://arxiv.org/pdf/physics/0001020.pdf >>>> - Why Occam's razor works >>>> - Why the postulates of QM hold >>>> - http://iridia.ulb.ac.be/~marchal/publications/SANE2004MARCHAL.pdf >>>> - Why physics is quantum mechanical >>>> >>>> Bruno has not proved this. The real question is why do we observe a >>> classical world? >>> >> >> Everett and H. Dieter Zeh explained this. >> > > No they didn't. Zeh's ideas of decoherence go some distance, but Everett > is totally irrelevant to this. > Do you think something more than decoherence is needed to get there? > > >> Why certain qualia are incommunicable >> >>> All quail are incommunicable by definition. Not something that requires >>> explanation. >>> >> >> Getting a explanation is better than having to accept it by definition. >> > > See above re: Newton and falling apples. 'whys' are not the stuff of > science. > The "beginning of infinity" in the title refers to several things but especially to human progress. The book discusses the rapid progress we've seen since the Enlightenment, and its cause: the rational quest for good explanations. David Deutsch > > >> Why do you consider it a failure? Where does Nominalism succeed where >>>> Platonism fails? >>>> >>> >>> Scientific realism rejects platonism. And scientific realism is where >>> the progress has been made. And that is nominalism wrt mathematics. >>> >> >> What does Nominalism have to do with "scientific realism"? Nominalism is >> an anti-realist idea. >> > > You seem to be using the old scholastic notion of nominalism. > "In more recent usage, 'nominalism' is often employed as a label for any > repudiation of abstract entities, whether universals or particulars, and > thus embraces the rejection of such things as propositions, sets, and > numbers." (Oxford Companion to Philosophy, OUP, 2005) > But then what is arithmetical truth? We have no label for it. It cannot be derived from or defined by labels. > > Using stanford's definition: >> >> "Scientific realism is a positive epistemic attitude toward the content >> of our best theories and models, recommending belief in both observable and >> unobservable aspects of the world described by the sciences. " >> >> > There are as many definitions of scientific realism as there are > philosophers of science. The central core, which is all I require, is that > there exists an external, mind-independent world. > It is clear to me how you have come to accept that the Hubble volume is real. What is unclear to me is how you have come to accept that the Mandlebrot set (or any other structure besides the one that contains you and me) is not real and is not also part of a mind-independent world. > > >> Unless you want to artificially separate mathematics from "the sciences", >> shouldn't someone who advocates for scientific realism recommend belief in >> the observable and unobservable aspects of reality described by the >> sciences (which includes math)? >> > > Nominalism is not in conflict with scientific realism as I am using the > term. > > >> Or is it because math and science are two different departments in your >> university that math is somehow different, and not involved in the >> furtherance of human knowledge? "Science" means "knowledge" it doesn't mean >> "physics, chemistry, biology". >> >> >>>> I await your reason, argument, or evidence. >>>>>> >>>>> >>>>> Arithmetical realism is part of platonism, if not the whole of it. And >>>>> arithmetical realism is manifestly false -- numbers are not things. >>>>> >>>> >>>> What is a thing anyway? >>>> >>>> Maybe the relationships are all that exist. Maybe the world is made of >>>> math. At first that sounded nuts, but when I thought about it I hard to >>>> wonder, what exactly is the other option? That the world is made of >>>> "things"? What the hell is a "things"? It was one of those concepts that >>>> fold under the slightest interrogation. Look closely at any object and you >>>> find it's an amalgamation of particles. But look closely at the particles >>>> and you find that they are irreducible representations of the Poincaré >>>> symmetry group--whatever that meant. The point is, particles, at bottom, >>>> look a lot like math. -- Amanda Gefter >>>> >>>> >>> So what? >>> >> >> So why is quark a thing, but a Calabi–Yau manifold is not? How are you >> drawing the distinction? >> > > Given that reality is external and mind-independent, quarks, since they > are theoretical constructs, may or may not be part of the furniture of > reality. "Things", if you want a definition, are the 'ding an such' of Kant. > Do you think there is there some underlying principle that determines which "dings and such" are real and which are not? Is your belief that only the "ding and such" you can see are real? > We might discover some of their properties, but we can never know the > "thing" in itself. Theoretical entities are generally dealt with by > nominalism, as above. > Most scientists would say quarks are real, because they are part of successful theories which have explanatory power. > > > Calabi-Yau manifolds are mathematical constructs, depending on the > definitions of topological manifolds. They are certainly theoretical items > that have no mind-independent existence. > Most string theorists would guess that Calabi-Yau manifolds are real, because they are part of successful theories which have explanatory power. The more you keep pushing this, the closer you get to seeing there is some truth to the Quine Putnam indispensability argument. You can't remove mathematical objects and numbers from our scientific theories. > > >> What separates the existent from the non-existent? >>>> >>>> >>>> It might be that at a certain level of description it becomes >>>> impossible to adequately represent the world other than mathematically. ... >>>> So yeah, you might think, if we eventually did have a one-to-one >>>> mapping, what could be the grounds for denying that reality was >>>> mathematical? I'm not really sure. I suppose I'm very skeptical of anything >>>> in philosophy that purports to explain the difference between abstract >>>> maths and maths that's substantiated. Because in the end, what could >>>> possibly explain that difference in terms of? Like, I reject the question >>>> 'What breathes fire into the equations?' Because anything you say is just >>>> gonna be figurative, right? Because you'd say, 'Well, there's the abstract >>>> maths and then the actual universe is a sort of substructure of all the >>>> possible structure there could be. So what's the difference between the >>>> uninstantiated structure and the instantiated structure?' Well, the >>>> philosopher will say there's a primitive instantiation relation or >>>> something--you could invent some metaphysical language to talk about it, >>>> but to me that's no different from saying that some of the maths has pixie >>>> dust in it. It's not going to do any work. Because what could it possibly >>>> connect to that would have any meaning? If you ask questions in science >>>> like 'What causes an earthquake?' you appeal to conceptual resources and >>>> those are non-empty because they're tied to observation. But maths--pure >>>> maths isn't tied to observation. If the theory of everything id a >>>> mathematical theory, how would you test it? It would have to have some >>>> content that has to do with something other than mathematics. -- James >>>> Ladyman, when asked "Does that mean the physical world is made of math?" >>>> >>>> >>> That sounds confused. But if anything, Ladyman is arguing for scientific >>> realism >>> >> >> He's saying any attempt to draw a boundary between "instantiated >> possibility" and "uninstantiated possibility", or between "physical >> structure" and "mathematical structure" is doomed to be ad hoc. >> > > He has a very good point, then. The problem with identifying "things" in > terms of their relations to other things, as Muller seems to do, is that > you make things into mathematical structures, and that is what Ladyman is > rejecting as ad hoc. This is a straight rejection of such ideas as > Tegmark's 'Mathematical (or Computable) Universe Hypothesis'. The universe > has its inherent physical structure, which is part of the 'ding an such', > which is not identified with any 'mathematical structure'. > You think there is no mathematical structure that can be identical to our physical universe with?! This is very surprising to me, why would this not be the case? > > >> what is your alternative?) >>>>>>>>> >>>>>>>>> Nominalism. >>>>>>>>> >>>>>>>> >>>>>>>> Incompleteness disproves nominalism. Arithmetical truth was proven >>>>>>>> not only to be not human defined, but to be not human definable. >>>>>>>> >>>>>>> >>>>>>> What has arithmetical truth got to do with it? >>>>>>> >>>>>> >>>>>> The independence of arithmetical truth *is* Platonism. With it you >>>>>> get all the consequences of that infinite truth: >>>>>> >>>>>> - The truth that 9 is composite implies the existence of its >>>>>> factor 3. >>>>>> - The truth of the Nth state of the machine during the execution >>>>>> of a Kth program implies the existence of the execution trace of >>>>>> program K, >>>>>> etc. >>>>>> >>>>>> >>>>> You are making the usual mistake of taking the existential quantifier >>>>> over a domain as an ontological statement. >>>>> >>>> >>>> Why should one's ontological opinions take precedence over what our >>>> best theories tell us? >>>> >>> >>> Our best theories are based on scientific realism, not mathematical >>> realism. >>> >> >> I say that's a meaningless distinction. >> >> >>> >>> >>>> You have still not addressed that nominalism is disproved by >>>> incompleteness. >>>> >>> >>> You have not shown that it is. >>> >> >> Nominalism holds that math is invented, that math is a game played with >> symbols where all the nuance comes down to how we chose the starting rules >> (axioms). >> >> Incompleteness (as well as Turing's halting problem) shows that >> arithmetical truth, or even the question of whether or not any program will >> complete are beyond the capacity of any axiomatic system to prove. >> Regardless of the starting rules chosen, no finite set of rules can define >> all of arithmetical truth. Truth will always be bigger than what can be >> proved within any axiomatic system. >> > > Sure. > > >> Therefore, the notion that math is invented is not tenable. >> > > That does not follow. The sets of axioms that we can employ is effective > unlimited, but all invented. > I know, I said as much. But arithmetical truth does not come from the axioms we invent. That was my point. > > The science of whether or not certain Turing machines halt is an >> objective science. One we explore, not create nor invent. >> > > It depends on the construction of the TM. There can be intersubjective > agreement about the structure of the machine. But the question as to > whether it halts is undecidable in general. It is not empirical, because we > can never know in whether any machine that has not yet halted will ever > halt. > > So is computer science part of your "scientific realism" which deals with and considers as real both the observable and unobservable objects of our theories? > > >> Numbers are just names, not existing things. >>>>>>> >>>>>> >>>>>> Again, where is your evidence? I gave you mine in support of >>>>>> Platonism. >>>>>> >>>>> >>>>> You gave no viable evidence for platonism. >>>>> >>>> >>>> See above. When simple theories explain many facts, that's generally >>>> taken as evidence in support of the theory. >>>> >>> >>>> >>>>> >>>>> >>>>>> If you have no evidence contrary to Platonism you should at least >>>>>> remain undecided/agnostic/humble on the matter. >>>>>> >>>>> >>>>> Why? Platonism rests on a confusion. I reject that confusion, and >>>>> hence platonism. >>>>> >>>> >>>> What is the confusion? >>>> >>> >>> Existential quantifiers confused with ontology. >>> >>> >>>> What replaces it at the simplest level is nominalism -- numbers are >>>>> names, not things. >>>>> >>>>> >>>> >>>> Let's define what is meant by "thing" first. Then we can debate >>>> whether or not numbers meet that definition, and whether or not it is >>>> important to the question of whether numbers and their relations could >>>> explain the appearance of reality. >>>> >>>> But before that, let's address this question: *Do you believe it is >>>> possible (in principle) that the physical universe could be explained from >>>> something more primitive?* >>>> >>> >>> No. >>> >>> >> What is the rational basis for your answer? >> > > Rejection of mathematical realism and acceptance of my minimal idea of > scientific realism -- the existence of an external, mind-indpendent reality. > > Why do you think arithmetical or mathematical realism does not qualify as an external mind-independent reality? The answer of "*No*" to my question "*Is it possible that the physical universe could be explained from something more primitive?*" signals a quasi-religious belief. There is little point in trying to debate any further on this question while you hold so firmly to this belief. Jason -- 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 view this discussion on the web visit https://groups.google.com/d/msgid/everything-list/CA%2BBCJUhkq62dm3%2B2XvMSZyA_dg_84yx1w79Gs8-PX%3D%3DCHT%3DoGA%40mail.gmail.com.
