• tom
    1.5k
    I have no arguments against this nonsense; I'm just the dunce, for now. Just here to throw some confetti. Confetti sometimes gets deleted, but sometimes it scatters widely and adds a nice dolup of humanity to an otherwise robotic landscape of laconic lunacy. The confetti isn't for you, tom; don't worryNoble Dust

    Maybe you could do the decent thing, and stop wasting people's time?
  • Noble Dust
    7.9k


    Not at all; I'm the dunce. I'm doing the decent thing and supplementing people's time against your utter robotic roboticness. :rofl:
  • TheMadFool
    13.8k
    That anything that 'explains everything' explains nothing.Wayfarer

    Really? You see no unifying principle at work?

    The trend (if I'm correct) seems to be to look for a unified theory that ''explains everything''.

    Do you think that's a dead end enterprise?
  • MetaphysicsNow
    311
    "Every finitely realizable physical system can be perfectly simulated by a universal model computing machine operating by finite means"
    That's what Deutsche takes to be his physical version of the (unproven/unprovable) Church-Turing thesis.
    There are a handful of scientists who believe that a universal computer cannot be realized, but that is a technical argument in computer science. The issue here seems to be more the following question: are human beings finitely realizable physical systems? If they are not, then the Deutsche principle is entirely irrelevant. Of course, the Deutsche principle itself does not provide the means to answer that question, and was not intended to.
  • tom
    1.5k
    That's what Deutsche takes to be his physical version of the (unproven/unprovable) Church-Turing thesis.MetaphysicsNow

    It is proved that current known laws of physics obey the Deutsch Principle. It is conjectured that all future laws must also.

    There are a handful of scientists who believe that the a universal computer cannot be realized, but that is a technical argument in computer science.MetaphysicsNow

    The earliest known design of a universal computer is Babbage's Analytic Engine.
  • MetaphysicsNow
    311

    The earliest known design of a universal computer is Babbage's Analytic Engine.
    Whatever Babbage's Analytic Engine was, that it was the realization of a universal computer is what the computer scientists I am talking about deny. Specifically they deny (in fact they claim to be able to prove) that there are computable functions that cannot be computed on any machine capable only of a finite number of operations.
    It is proved that current known laws of physics obey the Deutsch Principle. It is conjectured that all future laws must also.
    That says nothing to the question whether the principle applies to human beings.
  • tom
    1.5k
    Whatever Babbage's Analytic Engine was, that it was the realization of a universal computer is what the computer scientists I am talking about deny. Specifically they deny (in fact they claim to be able to prove) that there are computable functions that cannot be computed on any machine capable only of a finite number of operations.MetaphysicsNow

    That is almost funny.

    That says nothing to the question whether the principle applies to human beings.MetaphysicsNow

    I see, the Deutsch-Principle applies to Reality, but not humans.
  • MetaphysicsNow
    311
    @tomThe Deutsche principle applies to physical systems. Physical systems are part of reality, sure, but whether or not human beings are just physical systems is precisely the issue in question and so whether or not the Deutsche principle applies to them is a question the Deutsche principle is not going to be able to answer.

    I'm not sure why you think the first remark is funny - I didn't find anything particularly amusing about this paper
  • Wayfarer
    22.4k
    Really? You see no unifying principle at work?

    The trend (if I'm correct) seems to be to look for a unified theory that ''explains everything''.

    Do you think that's a dead-end enterprise?
    TheMadFool

    The point I was making is that to rationalise everything about 'free will' and human choice, which are huge topics in their own right, in terms of the principle of natural selection, amounts to a huge over-simplification. You can tell any number of 'just-so stories' about what is likely to enhance a species' "ability to survive" but it doesn't amount to anything. Actually now that I go back to the start of the thread, SLX's initial response more or less sums up the whole issue. There's nothing else needs saying.
  • TheMadFool
    13.8k
    You can tell any number of 'just-so stories' about what is likely to enhance a species' "ability to survive" but it doesn't amount to anythingWayfarer

    The fact that we humans, the most successful life-form, have free will or the illusion of it doesn't say anything about the process (evolution) that got us there seems quite unbelievable to me.

    It isn't something I believe. I just wanted the views of others on the matter. Thank you.
  • tom
    1.5k
    I'm not sure why you think the first remark is funny - I didn't find anything particularly amusing about this paperMetaphysicsNow

    I think it is hilarious when people trawl the internet in desperation. Anyway, you made the amusing claim that:

    Specifically they deny (in fact they claim to be able to prove) that there are computable functions that cannot be computed on any machine capable only of a finite number of operations.MetaphysicsNow

    Name me a computable function that cannot be computed. I'll wait.
  • MetaphysicsNow
    311
    The claim made is not that computable functions cannot be computed, that would be a contradiction in terms. The claim is that there are computable functions that cannot be computed by specific types of computing machine (i.e. Turing machines and their extensions). Read the work of S.G. Akl if you are really interested in specific examples.
  • Streetlight
    9.1k
    It's also worth checking out the work of Robert Rosen, who showed quite definitely [PDF] that the C-T thesis can hold for physical systems only under very specific constraints, and that, if those constraints do not hold, that the thesis doesn't really say much about anything at all regarding those systems. In any case, that the C-T thesis is applicable to everything is an article of faith, and hardly some undeniable principle.
  • MetaphysicsNow
    311
    Point taken. In fact when I admitted that the Deutsche principle applies to physical systems, I should have more accurately stated that it applies only to finitely realizable physical systems.
  • tom
    1.5k
    The claim made is not that computable functions cannot be computed, that would be a contradiction in terms. The claim is that there are computable functions that cannot be computed on specific types of computing machine (i.e. Turing machines and their extensions). Read the work of S.G. Akl if you are really interested in specific examples.MetaphysicsNow

    What has the Turing machine got to do with any of this, or Godel for that matter? What laws of physics do Turing machines obey?
  • Streetlight
    9.1k
    I didn't find anything particularly amusing about this paperMetaphysicsNow

    This is a really interesting paper btw. Rosen actually drew a parallel between C-T and Godel as well, some time back: "What we today call Church’s Thesis began as an attempt to internalize, or formalize, the notion of effectiveness. It proceeded by equating effectiveness with what could be done by iterating rote processes that were already inside—i.e., with algorithms based entirely on syntax. That is exactly what computability means. But it entails commensurability. Therefore it too is false. This is, in fact, one way to interpret the Godel Incompleteness Theorem. It shows the inadequacy of repetitions of rote processes in general. In particular, it shows the inadequacy of the rote metaprocess of adding more rote processes to what is already inside." (Rosen, "The Church-Pythagoras Thesis", in Essays on Life Itself).
  • MetaphysicsNow
    311
    @tom
    What has the Turing machine got to do with any of this, or Godel for that matter? What laws of physics do Turing machines obey?
    To the first question, I suggest you read the papers referred to - and note that the remark was about Turing machines and their extensions (Deutsche's universal model computing machine is an extension of a Turing machine).
    To the second question, is it a trick one? Turing machines (and their extensions) are abstract constructs, as such the notion of obeying a law of physics does not apply to them. If you are talking about actual physical machines that attempt to implement the operations of a Turing machine, then I suppose contraptions like that must obey all the same laws of physics that any physical contraption obeys. Why? What's your point?
  • Heiko
    519
    and the implications of that would be...???TheMadFool
    No need to search for the garden inside the house.
    A scientific investigation on the matter would be possible.
  • Heiko
    519
    I'm not sure why you think the first remark is funny - I didn't find anything particularly amusing about this paperMetaphysicsNow
    I do. Introducing time into mathematics is really funny. Like "2+2=4, but only if you answer in less than 3 seconds. It's 5 otherwise."
    And then I write 2+2=4 - is this the correct answer for the 2+2-problem?
  • tom
    1.5k
    To the first question, I suggest you read the papers referred to - and note that the remark was about Turing machines and their extensions (Deutsche's universal model computing machine is an extension of a Turing machine).MetaphysicsNow

    Babbage's Analytic Engine is a universal computer, as are PCs. These are all finite state machines. Ignoring the fact that Turing machines do not exist, they are not finite state machines.

    To the second question, is it a trick one? Turing machines (and their extensions) are abstract constructs, as such the notion of obeying a law of physics does not apply to them.MetaphysicsNow

    Right, they are abstractions obeying abstract rules, not real physical systems obeying the laws of physics.

    Physical systems that obey the laws of physics may be emulated on certain other physical systems that possess the physical property of computational universality.

    What has Godel got to do with any of this?
  • MetaphysicsNow
    311

    What has Godel got to do with any of this?
    Take it up with Akl and co. - the paper I linked to draws a parallel between Godel's work on completeness and consistency in arithmetic and the impossibility of acheiving a universal computer. I have not read Rosen, but given what @StreetlightX says, it seems he (Rosen) also thinks there is an implication of that work on the Turing-Church thesis. Curious that Deutsche did not make any reference to Rosen's work.

    Right, they are abstractions obeying abstract rules, not real physical systems obeying the laws of physics.

    Physical systems that obey the laws of physics may be emulated on certain other physical systems that possess the physical property of computational universality.
    You don't seem to understand that in the Deutsche principle which you presume to be relevant to this thread, the universal model computing machine he is referring to is an abstract model, he is not using the term to refer to actual nuts and bolts and silcon-chipped physical machines. Computational universality is a mathematical construct. Deutsche's principle is about the extent of what that construct can be used to model. Read the paper you linked to, his brief discussion of what a UMCM is makes it clear that it is an abstract model.

    Babbage's Analytic Engine is a universal computer, as are PCs. These are all finite state machines. Ignoring the fact that Turing machines do not exist, they are not finite state machines. — tom

    You display here even more confusion about the abstract notion of a machine, on the one hand, and its physical implementations, on the other. If by "universal computer" you mean to evoke the same concept that Deutsche is using when he talks about universal model computing machines, your statement is false, since UMCMs (like Turing machines) have infinite memory, something which no actual physical implementation of any abstract machine actually has. Furthermore, a finite state machine is a mathematical construct just like a Turing machine, in a sense it is a conceptual restriction on a Turing machine, just as Deutche's UMCM is a conceptual extension of a Turing machine.

    The real point here, anyway, and one which you seem to be overlooking by getting bogged down in nitpicking about technicalities - presumably the aim being to catch me in an outrageous error - is whether the Deutsche principle applies to human beings andthat question turns on the philosophical question whether human beings are finitely realizable physical systems, about which the Deutsche principle has nothing to contribute.
  • tom
    1.5k
    Take it up with Akl and co. - the paper I linked to draws a parallel between Godel's work on completeness and consistency in arithmetic and the impossibility of acheiving a universal computer. I have not read Rosen, but given what StreetlightX says, it seems he (Rosen) also thinks there is an implication of that work on the Turing-Church thesis. Curious that Deutsche did not make any reference to Rosen's work.MetaphysicsNow

    It's clear you don't know what Godel has to do with any of this, so let me explain. The laws of physics are written in a mathematics which is consistent, complete and decidable. Any calculation that you have ever carried out, or that a computer has carried out, or any finite state machine will ever carry out, in the entire history of the universe, will use a mathematics that is consistent, complete, and decidable.

    So Godel has literally nothing to do with this.

    And, universal computers can emulate any finite physical system.

    You don't seem to understand that in the Deutsche principle which you presume to be relevant to this thread, the universal model computing machine he is referring to is an abstract model, he is not using the term to refer to actual nuts and bolts and silcon-chipped physical machines.MetaphysicsNow

    You really are a comedian! Yes, he has a model of a real computer that can be built. That is why there is an entire academic industry focused on trying to construct a quantum one. We have classical machines already.

    The real point here, anyway, and one which you seem to be overlooking by getting bogged down in nitpicking about technicalities - presumably the aim being to catch me in an outrageous error - is whether the Deutsche principle applies to human beings andthat question turns on the philosophical question whether human beings are finitely realizable physical systems, about which the Deutsche principle has nothing to contribute.MetaphysicsNow

    The Deutsch Principle applies to all of Reality, even humans.
  • MetaphysicsNow
    311
    The Deutsch Principle applies to all of Reality, even humans.
    Wrong, the Deutsche principle applies explicitly to two things and two things only, finitely realizable physical systems and universal model computing machines, neither of which in isolation nor in conjunction can be claimed to constitute all of reality without further argument. But I've had enough now, I'll go and join @Noble Dust in the dunce's corner.
  • Wayfarer
    22.4k
    Deutsch is the cargo cult leader for the digital age.
  • MetaphysicsNow
    311
    And tom is one of his altar boys.
  • tom
    1.5k
    Wrong, the Deutsche principle applies explicitly to two things and two things only, finitely realizable physical systemsMetaphysicsNow

    You don't think humans are finite physical systems?
  • tom
    1.5k

    Wow! The laws of physics don't apply to humans. Now, that really is funny.
  • Wayfarer
    22.4k
    They govern how fast you would fall if you fell out of the window, but not what you’d think when you were going down. :razz:
  • jkg20
    405
    I think @Wayfarer probably hit the nail on the head, but also - although I do not think MN needs any help from me - simply to respond "No" to your question doesn't commit MN to any particular position one way or another. Your original question was "So you don't think that humans are finitely realizable physical systems?" responding "No" to that question does not entail that MN thinks that humans are not finitely realizable physical systems - it's a subtlty concerned with the scope of negation which may have escaped you. He may believe, for instance, that the notion of a finitely realizable physical system, or indeed even the notion of a human being, is not clear enough to be able to reach any reasonable conclusion concerning whether one is an instance of the other or not, and in which case the reasonable position is probably to suspend judgement.
bold
italic
underline
strike
code
quote
ulist
image
url
mention
reveal
youtube
tweet
Add a Comment

Welcome to The Philosophy Forum!

Get involved in philosophical discussions about knowledge, truth, language, consciousness, science, politics, religion, logic and mathematics, art, history, and lots more. No ads, no clutter, and very little agreement — just fascinating conversations.