Re: Fundamental problems in Physics

[Tim Gwinn <***>]

Howard,
See interposed.
Regards,
Tim

> -----Original Message-----
> From: ROSEN Forum [mailto:*** Behalf Of Howard
> Pattee
> Sent: Thursday, December 16, 2004 1:40 AM
> To: ***
> Subject: Re: Fundamental problems in Physics
>
>
> Tim,
> This kind of categorical statement of how physicists think is what I am
> criticizing in my post to Judith.
>
> >TG: To the extent that physics community limits their formalisms to
> >state-based paradigms, they are effectively mechanists and reductionists,
> >whether they explicitly consider themselves as such or not.
>
> HP: The concept of "state" is not set in Rosen stone, nor are
> "machine" and
> "reductionism." States can refer to memory or time intervals or timeless
> configurations. Machines can be constraints or boundary conditions or
> dissipative structures with inherent error. And for reductionism
> you should
> read philosophy. It isn't so easy to define and has many manings. Physics
> also uses complementary models, one can be reductionist and the other
> emergent. It is better not to tell people you don't know what their
> philosophy is!


TG: As I said, they are "effectively mechanists and reductionists", when
adhering to that paradigm. I did not assert what they think or their
philosopical beliefs might be. It is the nature of the Newtonian state-based
paradigm that it is an embodiment of Church's Thesis and all that that
entails, as laid out in LI. Clearly in my remarks I was using Rosen's
definitions of "state". I do not know of a modern physics which uses some
notion of 'state' that fundamentally differs from Rosen's.


>
> TG: "Closed loops of entailment may be a useful abstract
> concept."?? I'm not
> sure why you bother with the ROSEN list if this is only an
> abstract concept
> to you with no counterparts in the external world.
>
> HP: I meant closure was an abstract principle used in modeling,
> as opposed
> to an explicit model. Symmetry in physics is an abstract principle. It is
> not a model.


TG: I am talking about closed loops of entailment in models, not "closure"
(whatever that is). The whole basis of the modelling relation is the
matching of entailment structures between both sides of the MR. Whether
those entailments structures are predicative or impredicative (loops), one
seems to me no more or less "abstract" than the other.


> TG: The predicative limits of entailment in Turing computability
> do not rest on whether one computes exact functions or their
> approximations,
> or whether the Turing machine is a UTM or a finite TM.. It is a limitation
> of the very nature of computability.
>
> HP: Of course I agree. I have not made my point clear. I am saying that
> Turing computability is indeed a formal limit, but a limit that
> has not yet
> caused a problem with any physical or biological models or any other
> programs that I know about.
>
> TG: One can certainly utilize simulations rather than models to
> circumvent
> this
> limit .  .  .
>
> HP: That is what I am pointing out.
>
> TG: .  .  . but then one does not have a commuting modelling relation.
>
> HP: That's not often a fatal error. The Hertzian "commutation" is not a
> formal commutation, but an analogy. It is a "conformation"
> relation that is
> not well defined because it is so different for different models and
> contexts. How close and to what types of observables does the formalism
> have conform before it is an acceptable model? That type of
> question makes
> Rosen's distinction between simulation and model. This is crucial
> for some
> models and irrelevant for others. It depends on the question you want to
> answer, and that is up to the modeler.


TG: Ah, now we come to the crux of the matter. What you previously seemed to
assert to be the same things - Hertz's discussion in the Introduction of the
Principles of Mechanics and the Rosen Modelling Relation - as represented in
your diagram "ELABORATED HERTZ/ROSEN MODEL COMMUTATION DIAGRAM" combining
the two - are now very different things. If you wish to promote an entirely
different epistemological basis for science founded on your interpretation
of Hertz, then fine, but this really isn't a useful forum for that.

I say this not to be exclusive, but because Rosen's philosophy of science
and his arguments all flow from the commuting (in Rosen's sense) modelling
relation being the epistemological underpinning. Without the requirement for
the modelling relation to commute (in Rosen's sense), the whole epistemology
collapses and there is no force of argument for the existence of Rosennean
complexity or a requirement for complementary models or analytic <>
synthetic or for any importance of organization, a distinction between
models and simulations, etc.


> Howard
>
>
>
>