Dear Bruno, On Tuesday, January 21, 2014 1:11:16 PM UTC-5, Bruno Marchal wrote: > > > On 21 Jan 2014, at 15:45, Alberto G. Corona wrote: > > > It is a phisical definition of computation in the physical world, to > > distinguish what physical phenomena are computations and what are not. > > I don´t care about mathematical oddities. > > But nobody has found such a definition. Physical computation are only > recognized as computation in machine that we can build, from subset of > physical laws, to implement the mathematical definition. >
Why not? The solution is staring us in the face. We have to recognize that the class of Physical systems have related a class of Representations: all of the possible measurement data of a physical system. We can examine the measurement data and generate simulations of the physical system in order to predict its behavior. We call this Physics. > > Then it is a theorem that we cannot recognize something as being a > computation, even in the arithmetical reality. Sure, but that assumes that one is dealing with an infinite set. The set of measurable data of a physical system is not infinite. > We can build one and > recognize those we built, or we can bet that some process computes, > like when saying "yes" to a doctor. But there is no general means to > see if something is a computation or not, and this will depends in > part of we look at it. > This remark seems to have an interesting implication: that if I examine some string of code that might happen to be a simulation of a physical system, I will not be able to know which physical system it is. We get universality of computation this way? > > Computability is a notion discovered in math. It is related to the key > discovery of Turing (also some others) of the universal (Turing) > machine. > But this universality comes with a great price. It abstracts away time and space and all the rest of our local reality. > > You can defend naturalism, or physicalism, and you have the right to > believe in a primitive physical universe. I am agnostic, and I have to > be, if only because we have not yet decided between Plato and > Aristotle. We are very ignorant, notably on the mind-body question. > Umm, your agnosticism does not seem very strong. You defend AR very strongly. I have offered you a sketch of a solution to the mind-body problem and you vigorously attack it with demands for formalism that I cannot write. What if both Plato and Aristotle are wrong? > > I do not defend computationalism. I just show that IF we assume it, > then we get a constructive and testable platonic theology, which > explains physics. And I have done a piece of the derivation and tested > it. > It does not take much to show examples of your defend, Bruno. You are lying to yourself in claiming "I do not defend computationalism." You will not consider any alternative. > > If you are right on metaphysical naturalism, with a real ontological > universe, then comp is wrong. That is all what I say. > Pfft, that is a false dichotomy. It is not necessary to assume ontological primitives that have some set of properties to the exclusion of others. You hold onto this dichotomy because it is your tool to defend AR. > > > > > > Computation in this sense is a manifestation of teleological entities > > capable of maintaining his internal structure. > > I can accept this as a putative truth about a notion of physical > computation, but this has not yet been defined. Why do we need a well founded definition? I offer a non-well founded definition: Computation is any transformation of Information. Information does not need to be of physical systems; it can be of representational systems: like you favored Sigmas and PA. > "reducing entropy" was > a good try, less wrong than "quantum computation" (despite here Turing > universality is verifiable), but it does not work as nature can > compute without dissipating energy (indeed quantum computers requite > that). > Where do you get that rubbish idea? Quantum computation has been proven to require resources if it is to be evaluated. Sure, the evolution of the phase is Unitary, but this holds for QM systems in isolation. The only real example of such is the Universe itself. We get the Wheeler-Dewitt equation with its vanishing of time. > > > > > Math do not compute. > > That does not make a lot of sense. > Math performs no actions on its own. > > > > > Computers do not compute, > > Only computers compute. That's almost tautological. > For example universal computers compute anything computable. > > I often use the word "computer" in the sense of the french > "ordinateur", which means all purpose computer or universal computer. > > > > Books do not compute. > > We agree on this! > > > > > Is people that compute > > with the help of them. > > > That makes sense, if only because the Turing machine describe very > well how a person compute with pencil and paper, going through > different state of mind. Yes, people can compute, but computer compute > too, with the standard mathematical definition. > > > > > > Bruno marchall invoking church thesis to > > convince us flooding the list with comp theory > > Well, many people agree with the comp axioms, and are interested in > thinking on the conceptual consequences. Then Church thesis is rather > important to understand the generality of the notion. > > > > > > talking about non > > computability does compute too . > > I don't understand the sentence. > > > > > as well as any living being. > > > > That definition of computation is more restrictive and wider that the > > traditional one. Is more restrictive for obvious reasons. It is wider > > because it depart from the legomania of digitalism. > > But that is the essence of computation. Then it is a beautiful miracle > in AUDA (but implicit in the UDA) that the first person appears not to > be computable or even nameable from her first person point of view. > In fact S4Grz exists by an arithmetical tour de force. It is a formal > logic of the non-formalizable. It explains why, from the 1p view, we > cannot avoid the depart from the legomania of digitalism. > But comp explains the why and the how. > > > > > Moreover it is an > > operational definition closer to everyday reality and includes all > > that is traditionally called computer science and biology (and > > sociology) within a wider physical framework. > > May be. You did not provide a definition of physical computation. Nor > of "physical", which might help a skeptic like me. The only one you > gave was "reducing entropy". But it does not work. It might work for > life perhaps. It is certainly an interesting idea. But it is not > "computation". You can't change definition at will, or we are talking > about different things. The mathematical notion of computation is NOT > controversial. The physical notion of computation is not even > existing, and most attempts are controversial. The existence of my desktop computer is obvious to me.... > > > Bruno > > > > > > > 2014/1/21, Bruno Marchal <[email protected] <javascript:>>: > >> > >> On 20 Jan 2014, at 21:17, Alberto G. Corona wrote: > >> > >>> Computation is understood as whatever made by a digital computer or > >>> something that can be emulated (or aproximated) by a digital > >>> computer. > >> > >> OK. That's a good definition, and it is correct if ... we assume > >> Church's thesis. > >> > >> > >> > >>> So everything is a computation. > >> > >> Goddam! Why. Even just about what is true in arithmetic cannot be > >> emulated by any computer. > >> > >> I am afraid you might not really grasp what a computer is, > >> conceptually. See my answer to stephen yesterday, which shows wahy > >> Church thesis entails that most attribute of *machines* cannot be > >> computed by a machine. > >> > >> Or think about Cantor theorem. The set of functions from N top N is > >> not enumerable, yet the set of *computable* functions is enumerable. > >> > >> > >> > >> > >>> That is a useless definition. because > >>> it embrace everything. > >> > >> For a mathematician, the computable is only a very tiny part of the > >> truth. > >> > >> > >> > >> > >>> > >>> Everything is legoland because everything can be emulated using lego > >>> pieces? No, my dear legologist. > >> > >> Not veything can be emulated by a computer. few things actually in > >> usual math. Some constructivist reduces math so that everything > >> becomes computable, but even there, few agree. > >> In Brouwer intuitionist analysis he uses the axiom "all function are > >> continuous" or "all functions are computable", but this is very > >> special approach, and not well suited to study computationalism > >> (which > >> becomes trivial somehow there). > >> > >> > >>> > >>> What about this definition? Computation is whatever that reduces > >>> entropy. > >> > >> It will not work, because all computation can be done in a way which > >> does not change the entropy at all. See Landauer, Zurek, etc. > >> > >> Only erasing information change entropy, and you don't need to erase > >> information to compute. > >> > >> > >> > >>> In information terms, in the human context, computation is > >>> whatever that reduces uncertainty producing useful information and > >>> thus, in the environment of human society, a computer program is > >>> used > >>> ultimately to get that information and reduce entropy, that is to > >>> increase order in society, or at least for the human that uses it. > >> > >> The UD generates uncertainty (from inside). > >> > >> > >>> > >>> A simulation is an special case of the latter. > >>> > >>> So there are things that are computations: what the living beings do > >>> at the chemical, physiological or nervous levels (and rational, > >>> social > >>> and technological level in case of humans) . But there are things > >>> that > >>> are not computations: almost everything else. > >> > >> That is the case with the definition you started above, and which is > >> the one used by theoretical computer scientist. > >> > >> Bruno > >> > >> > >> http://iridia.ulb.ac.be/~marchal/ > >> > >> > >> > >> -- > >> 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] <javascript:>. > >> To post to this group, send email to everything- > >> [email protected] <javascript:>. > >> Visit this group at http://groups.google.com/group/everything-list. > >> For more options, visit https://groups.google.com/groups/opt_out. > >> > > > > > > -- > > Alberto. > > > > -- > > 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] <javascript:>. > > To post to this group, send email to > > [email protected]<javascript:>. > > > Visit this group at http://groups.google.com/group/everything-list. > > For more options, visit https://groups.google.com/groups/opt_out. > > http://iridia.ulb.ac.be/~marchal/ > > > > -- You received this message because you are subscribed to the Google Groups "Everything List" group. 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