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Open vs. Closed system

  1. Jul 14, 2006 #1

    Q_Goest

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    In his book, "Representations and Reality", Putnam states:
    How would you define an "open system" in this context? How would you define a closed system?
     
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  3. Jul 14, 2006 #2

    DaveC426913

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    You haven't provided enough context for my liking, but that's just me.
     
  4. Jul 14, 2006 #3

    Q_Goest

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    I've read Putnam's account and even from context, it is unclear. However, it must be clear to philosophers as Putnam's contention has gained considerable attention, primarily from Chalmers on the opposing field and Bishop on Putnam's side. I'll include relavent discussion from Davenport as well.

    From Chalmers.
    http://consc.net/papers/rock.html
    From Bishop:
    (Mechanical Bodies, Mythical Minds 2004)
    From Davenport:
    (Computationalism: The very idea)
     
  5. Jul 14, 2006 #4

    loseyourname

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    I think he is using the term in the normal thermodynamic sense. If I had to guess at a reason why he specifies the argument to only open systems, it is because a completely closed system can theoretically reach permanent homeostasis and cease to go into changing physical states as time passes. Don't quote me on that, though. Ask a chemistry expert.
     
  6. Jul 14, 2006 #5

    selfAdjoint

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    This is correct, except the stable state is known as "thermal equilibrium", not homeostasis. Homeostasis is the property some open systems have of maintaining an approximately stable internal state in the face of varying inputs. An example of that would be a mammalian body in varying temperatures. Homeostasis requires some "programming" on the part of the system that exhibits it.
     
  7. Jul 14, 2006 #6

    loseyourname

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    Thanks, Adjoint.
     
  8. Jul 14, 2006 #7

    selfAdjoint

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    THis is correct except that the stable state is known as thermal equilibrium, not homeostasis.

    Homeostasis is the property some open systems have of maintaining their internal state in approximate stability in spite of varying inputs from the environment. Animals, and especially mammals, are VERY homeostatic.
     
  9. Jul 14, 2006 #8

    Q_Goest

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    Thanks for the input Lose & Adjoint. I'd like to think that's what he's refering too, but after reading through a number of papers on the topic, I can't see any connection between Putnam's use of the term "open physical system" and the more conventional use. Unfortunately, I've lost my copy of the book. I had it a day or two ago <sigh> Regardless, take for example Chalmers:

    I don't see the importance of using the phrase "open physical system" here if it is used in the thermodynamic sense, unless I'm applying more importance to it than it deserves. Perhaps that's all there is to it. Perhaps 'open system' here is miss-leading, but I don't think so.

    I say this because the argument Chalmers uses against Putman is to say that "strong conditionals" and counterfactuals are important features of a computational mind. Chalmers argument seems to suggest the 'open system' is one which is disconnected somehow, such that one can't have a simple 1 to 1 mapping between an FSA with and an FSA without a mind. Chalmers claims that without the ability to duplicate all potential I/O, you can't preserve mentality. Bishop comes back and suggests "counterfactuals can't count". In each case the focus on Putnam seems to be on proving whether or not this 'mapping' of an alleged conscious FSA with an 'ordinary open system' is a valid argument.

    Take Bishop for instance, who claims that "over a finite time window, every open system implements the trace of a particular FSA … lead[ing] to panpsychism" and, by a reductio, "a suitably programmed computer qua performing computation can never instantiate genuine phenomenal states".

    The references to "open systems" seem to indicate only some stationary system in which states can be mapped. If they mean open system in the conventional sense, it seems misleading.

    If this is all sounding like nonsense, then you probably understand it as well as I do. I think I'm going to shove a water hose in my ear now, I can smell brain cells burning…
     
  10. Jul 16, 2006 #9
    From Chalmers' paper at

    http://consc.net/papers/rock.html

    The argument seems to rest on the fact that any given open system (such as a rock exposed to the rest of the universe) is in different maximal states at different times (assuming Putnam’s Principle of Non-Cyclic Behaviour) - and Putnam argues for this on the basis that every such system is exposed to electromagnetic and gravitational radiation from a natural clock.

    Thus (my understanding of Putnam's argument would be) it follows that over an infinite length of time such an open system would occupy every possible maximal state, and if each physical state is mapped to a different FSA then it follows that it would implement all possible FSAs?

    I find it hard to follow Putnam's argument, but is this what Putnam is basically claiming?

    Are each of the FSAs supposed to be implemented entirely within the rock itself, or do we have to take the environment into account as part of the enabling of the FSAs (after all, part of the basis for arguing that the rock occupies every possible maximal state is that it IS an open system, exposed to electromagnetic and gravitational radiation etc)?

    I would also certainly (at least) challenge his Principle of Non-Cyclic Behaviour.

    Finally - funny things happen when you play around with infinity. Remember Hilbert's hotel? I can prove that there are twice as many natural numbers as there are natural numbers, for example. Just because we let the experiment run for an infinite time does not (imho) entail that every possible maximal state will be visited, nor does it entail that every FSA will be implemented.

    Best Regards
     
    Last edited: Jul 16, 2006
  11. Jul 16, 2006 #10

    Q_Goest

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    Hi MF. After reading Putnam, Chalmers, Bishop, and a few others on this argument, I still wasn't following Putnam's original reasoning. He's even more difficult to understand than Chalmers and Bishop. I thought perhaps I was simply missing something to do with a philisophical open system because the arguments are also focused on a disconnected or disjointed system. I thought perhaps there was a relationship there that I was missing. On further review, I've concluded the term "open system" is exactly as Adjoint states, and I must be putting too much emphasis on the term. I don't see it as being crucial to Putnam's argument at this point.

    I'm not sure if Putnam's argument requires an infinite time period, though Chalmers mention something about this. I'm also unfamiliar with Putnam's principal of non-cyclic behavior. I'll open a new thread to discuss Putnam's work in more detail soon. It's difficult to understand but it seems to have drawn considerable attention from the philisophical community.
     
  12. Jul 16, 2006 #11

    selfAdjoint

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    I think this quote from your post #3:

    From Davenport:
    (Computationalism: The very idea)


    pretty much settles the issue. You can't get more thermodynamically open than a rock, and it's just the ordinary successive states of the rock that Putnam is referring to. He says he can use these successive states (he seems to need that external "clock' the flow of time; hence the system has to be open) can be used as a surrogate for any finite state machine, in other words as the instantiation of a Turning Machine. Hence a computational intelligence cannot be unique to human minds, since such computers are ubiquitous in Nature. I am just restating what Davenport says here. I can see problems with the mapping of any old succession of environmental states as a Turing machine; how do you erase?

    But Davenport also says he "disposes" of Putnam's thesis. How does he do that?
     
    Last edited: Jul 16, 2006
  13. Jul 18, 2006 #12

    Q_Goest

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    Ref: Davenport

    I wouldn't say that Davenport manages to do this. His paper isn't particularly convincing IMO, and I don't see anyone referencing him. I'll try and get something together on the issue shortly.
     
  14. Jul 18, 2006 #13

    selfAdjoint

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    I don't see why you're not convinced. Here is his argument:

    In other words, given some fixed set of transitions in the transition table, you can find some set of rock states at some time that implement that string of transitions. If you have some other set of transitions you have to find some completely different states of the rock which might be at some immense gap in time from the first. So just showning some typical string of transitions can be simulated doesn't do the job. What has not been shown is that you can implement the whole table and every path through it. So you can't use the rock to simulate the automaton.
     
  15. Jul 18, 2006 #14

    Q_Goest

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    I'm not sure your representation of Putnam's argument is correct, but assuming it is, I'll quote Maudlin:
    Also, Bishop presents numerous articles "Counterfactuals cannont count", "Dancing with Pixies" and "Mechanical Bodies, Mythical Minds"
    about which Chalmers remarks:
    Anyway, I've read most of these through, but still having trouble deciphering what the exact meaning of some of this is. There's a lot of work that's focused on this and plenty of debate on both sides. I don't see it as being as simple as Davenport makes it out. In any case, I still need a better understanding of the prior work.
     
  16. Jul 18, 2006 #15

    selfAdjoint

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    Frankly I think the whole rock thing is ridiculous. And anyway there are available alternatives to finite state automata as models of the mind. Note that if you include recursion you can reach an arbitrary number of states with a finite resource: It is not true (that I am disturbed (that (Chalmers comments that (Bishop presents...)...)...), the point being that you can't code these into a static transition matrix, or I don't think so (someone who knows can orrect me). Chomsky claims that anything expressible in a natural language can be simulated by a small automaton with recursion.
     
  17. Jul 24, 2006 #16
    A "closed system" can be defined as a system of which the internal properties in investigative question can not be substantively modified through existing external influence.
    In reality this is impossible.
    As such, a "closed system" is a fictional, idealized state of isolation, though very useful in certain examinations.
     
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