Re: Fundamental problems in Physics

[Howard Pattee <***>]

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: "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: 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.

Howard