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  1.  
    @angus

    There's no wiggling anywhere - and in fact none is needed. What are you talking about?

    If the model is incomplete or resource constrained, it may "predict" a violation. If it's a (imaginary) perfectly implemented theoretical model it's still subject to the same limitations surrounding any sufficiently powerful formal system.

    And if the model is based on principles that make it just reflexive enough, the same uncertainties apply.

    All you seem to be saying, in effect, is "if I program my model so that a violation of COE is impossible, no violation of COE will be observed".

    That would be true, but lacking in insight, and not the issue I'm discussing.

    How many models program violation of COE *out*? I'd guess that's a very small number - maybe zero. But perhaps implicitly by basing certain behaviours / approximations of behaviour on the "fact" of COE.

    If a model correctly encompasses sufficient physical laws with sufficient accuracy, what you'd expect is that COE emerges "for free". Unless there's something incomplete or inconsistent about the system as a whole. And how could that possibly be?

    So, "probable".
    • CommentAuthorBigOilRep
    • CommentTimeMay 6th 2010
     
    It's all "tinker says" that any such simulation was ever run in the first place, let alone it's allegedly anomalous result.
    •  
      CommentAuthorAngus
    • CommentTimeMay 6th 2010 edited
     
    @tt
    No.

    It is known that a violation of CoE cannot occur in a universe with constant laws, per Emmy Noether. That is a very general mathematical result. Nothing to do with the completeness of any particular model. So to the extent that mathematics describes the universe, it excludes violations of CoE under Noether's conditions.

    Models are mathematical representations of the universe. Therefore (whether or not experimental facts agree) they cannot predict a violation of CoE if they are executed correctly.

    A correct model that violates CoE has to violate the conditions of Noether's proof. That is contrary to observation so far. In effect your remark "if I program my model so that a violation of COE is impossible, no violation will be observed" is close to the mark, but it is not the programming that precludes the violation. It is the fundamental concepts behind any mathematical model.


    As to self-reference in physical law, I really don't know where it could come up. Can you provide an example?
    •  
      CommentAuthortimetrumpet
    • CommentTimeMay 6th 2010 edited
     
    @angus

    You describe it as a "general mathematical result", placing it squarely in the territory governed by GIT.

    The discussions of GIT as it relates to TOE underpin all these issues. Any sufficiently powerful formal system is inconsistent or incomplete. The question to answer is if a specific system - an imperfectly modelled subset of physical laws for instance - is nevertheless sufficiently powerful to in turn suffer from this limitation.

    Your mathematical model is, erm, mathematical. How would you propose to prove that it is sufficiently flexible to model reality and simultaneously constrained enough that it isn't subject to the vagaries of GIT? The more complete the model is in terms if the reality it represents, the more at risk it is of being incomplete or inconsistent in the formal sense.

    As to an explicit example of self reference in a physical law, no idea.

    But it's not necessarily something that would be easy to spot - indirect circular reference between multiple laws would be enough, and that can be difficult to recognise even in very simple contexts. If you read the Wikipedia article in question, it's this very question of unification / relationship of different physical laws that leads to considerations of incompleteness / inconsistency.


    ETA: Bed "probably". 3-way squash has done for me, but I'd be interested to pick it up again.
    •  
      CommentAuthormaryyugo
    • CommentTimeMay 6th 2010
     
    @Spectre
    FYI, you can edit your posts, remove the contents of the "extra" post and replace it with a single character.
    • CommentAuthorjoshs
    • CommentTimeMay 6th 2010
     
    Posted By: timetrumpet@joshs

    I don't think we disagree too much on this. But every non-trivial simulation is resource constrained in some way that makes the expression of errors or unexpected results a certainty if you know which edge-cases to exercise (or you exercise it inadvertently)
    That's a circular expression of claiming that resource constraints force error that violate fundamental principle. Even in your circling the drain argument you admit the program is in error if it violates its fundamental assumptions. In such a case if the program designer doesn't understand how to find the boundaries where the program generates incorrect results, then he is not competent to design the program. So you are still left in the losing position of trying to defend the disproven idea that a competent program premised on a rule it must universally hold can be written to find an exception to that universal rule. If the program is competently written, it does not violate its underlying rules. Saying that it can is a direct logical self-contradiction. It is a fail.


    eta note I'm explicitly separating out @tinkers claim to have found a result of this sort from any claim that it "proves" COE doesn't hold. In the absence of any other empirical data I'd also be looking hard at the accumulation of errors or invalid assumptions somewhere.
    •  
      CommentAuthoraber0der
    • CommentTimeMay 6th 2010
     
    Posted By: maryyugo@Spectre
    FYI, you can edit your posts, remove the contents of the "extra" post and replace it with a single character.

    ...or even 'whisper' it to yourself...
  2.  
    @joshs

    Your reply is difficult to parse. The fact remains that complex applications can exhibit errors in non-trivial and unpredictable ways, regardless of the intelligence of the developer when designing it or his diligence when testing it. All the more so for applications with broad or generalised functionality.

    Few applications are written from scratch and tend to build on progressive layers of abstraction previously laid down by other trusted 3rd parties, and subject themselves to various documented and undocumented sources of error. You may be able to identify the cause of emergent errors through this chain post-mortem, but is isn't reasonable or feasible to expect them all to be predicted.
    • CommentAuthorSPECTRE
    • CommentTimeMay 6th 2010
     
    @ Mary; thanks, my blog-fu sux.
    • CommentAuthorSPECTRE
    • CommentTimeMay 6th 2010
     
    So in timetrumpet's bizarre universe driven by free energy lunacy, if one were to buy an ordinary calculator at walmart, one should expect that the calculator will occassionally display a "5" in answer to the query "2+2=". This is because computer programmed systems can actually simply disregard their programming in favor of any other result even if not permitted by the basic rules of the program.
  3.  
    Posted By: timetrumpet@joshs

    Your reply is difficult to parse. The fact remains that complex applications can exhibit errors in non-trivial and unpredictable ways, regardless of the intelligence of the developer when designing it or his diligence when testing it. All the more so for applications with broad or generalised functionality.

    Few applications are written from scratch and tend to build on progressive layers of abstraction previously laid down by other trusted 3rd parties, and subject themselves to various documented and undocumented sources of error. You may be able to identify the cause of emergent errors through this chain post-mortem, but is isn't reasonable or feasible to expect them all to be predicted.


    They display "aberrant" and "unexpected" results because while we cannot make the millions of calculations in a blink of an eye to get there, they can, and will. This is why applications and operating systems often show unexpected interactions that can ruin your spreadsheets or destroy your registry. To the computer, killing the entire crew so that his contradicting orders are both met is not an aberration but cold logic to the extreme, so I'm sorry that I can't do this Dave.
  4.  
    @SPECTRE

    No. You're failing to apprehend the discussion. You should really stop before you embarrass yourself further.

    They will do what they're programmed to do (barring catastrophic hardware failure, cosmic ray events or other imponderables). This is not always what you intend them to do. There are a number of reasons of varying subtlety and complexity that may contribute to the degree of separation between the two. You might want to go and read up on a few.
  5.  
    @Drakkenmensch

    I don't disagree with any of that. Where I seem to part company with @joshs is the degree to which a failure can be anticipated. Context means a lot.
    •  
      CommentAuthorAngus
    • CommentTimeMay 6th 2010
     
    @tt
    You describe it as a "general mathematical result", placing it squarely in the territory governed by GIT.


    Clarify that please.
    • CommentAuthorSPECTRE
    • CommentTimeMay 6th 2010
     
    Posted By: timetrumpet@SPECTRE

    No. You're failing to apprehend the discussion. You should really stop before you embarrass yourself further.

    They will do what they're programmed to do (barring catastrophic hardware failure, cosmic ray events or other imponderables). This is not always what you intend them to do. There are a number of reasons of varying subtlety and complexity that may contribute to the degree of separation between the two. You might want to go and read up on a few.


    Because you're actually just plain wrong, which is no surprise, I'll simply answer by saying shit or get off the pot. Put up your evidence of your absurd claim that doesn't make any sense to any other person on this board except tinkerbell. Otherwise, your boring pontifications are just that; boring, rambling, and wrong. As Josh pointed out, your entire argument is an epic fail.
    • CommentAuthorjoshs
    • CommentTimeMay 6th 2010
     
    Posted By: timetrumpet@joshs

    Your reply is difficult to parse. The fact remains that complex applications can exhibit errors in non-trivial and unpredictable ways, regardless of the intelligence of the developer when designing it or his diligence when testing it. All the more so for applications with broad or generalised functionality.

    Few applications are written from scratch and tend to build on progressive layers of abstraction previously laid down by other trusted 3rd parties, and subject themselves to various documented and undocumented sources of error. You may be able to identify the cause of emergent errors through this chain post-mortem, but is isn't reasonable or feasible to expect them all to be predicted.
    Don't be so obtuse. If A is always true, then an algorithm that evaluates A as false is errant.
    • CommentAuthorjoshs
    • CommentTimeMay 6th 2010
     
    Posted By: SPECTRESo in timetrumpet's bizarre universe driven by free energy lunacy, if one were to buy an ordinary calculator at walmart, one should expect that the calculator will occassionally display a "5" in answer to the query "2+2=". This is because computer programmed systems can actually simply disregard their programming in favor of any other result even if not permitted by the basic rules of the program.
    Yes, because in TT's world, things are "complicated".
    •  
      CommentAuthorpcstru
    • CommentTimeMay 6th 2010
     
    Posted By: timetrumpet@SPECTRE

    No. You're failing to apprehend the discussion. You should really stop before you embarrass yourself further.

    They will do what they're programmed to do (barring catastrophic hardware failure, cosmic ray events or other imponderables). This is not always what you intend them to do. There are a number of reasons of varying subtlety and complexity that may contribute to the degree of separation between the two. You might want to go and read up on a few.


    So a simulation of a system based on known physics, which incorporates CoE as a basic assumption (as proved mathematically by E. Noether), could produce a result which shows additional energy and you say that there is a possibility (maybe just a very slim one) that the result is correct?

    Mathematically that is much the same as 2+2=5. How about a slightly more complex example - a^2+b^2=c^2. Mathematically we have a proof that this is true. Yet from what you say, a simulation which produces a result 5.0067 from a=3 and b=4, might just be right - albeit a slim possibility? If not, how is that different from any of the equations for motion, magnetism or charge?
  6.  
    Posted By: joshs
    Posted By: timetrumpet@joshs

    Your reply is difficult to parse. The fact remains that complex applications can exhibit errors in non-trivial and unpredictable ways, regardless of the intelligence of the developer when designing it or his diligence when testing it. All the more so for applications with broad or generalised functionality.

    Few applications are written from scratch and tend to build on progressive layers of abstraction previously laid down by other trusted 3rd parties, and subject themselves to various documented and undocumented sources of error. You may be able to identify the cause of emergent errors through this chain post-mortem, but is isn't reasonable or feasible to expect them all to be predicted.
    Don't be so obtuse. If A is always true, then an algorithm that evaluates A as false is errant.


    True, but not at issue.

    This particular point of disagreement rests on whether or not a developer who fails to anticipate that an errant result may be produced in some circumstances is an idiot. Your answers so far suggest that you hold this opinion. I strongly disagree.

    Modelling the behaviour of complex systems is usually iterative and approximate as opposed to symbolic and exact. You don't need to work to hard to understand where that leaves you in terms of certainty that the model will behave according to your *intention*

    Iteration is a rich source of error, and iteration is a cost that leads to approximation and consequent error in any complex simulation.

    You can't necessarily predict a problem or it's significance until you get there.
  7.  
    Posted By: joshs
    Posted By: SPECTRESo in timetrumpet's bizarre universe driven by free energy lunacy, if one were to buy an ordinary calculator at walmart, one should expect that the calculator will occassionally display a "5" in answer to the query "2+2=". This is because computer programmed systems can actually simply disregard their programming in favor of any other result even if not permitted by the basic rules of the program.
    Yes, because in TT's world, things are "complicated".


    And in your world as it happens.

    SPECTRE (and others) are trotting out pointlessly trivial examples that demonstrate that they don't understand the issue or how and where it may apply, rather than "proving" that there is no issue.

    They should do some reading. They can start with the Wikipedia reference.