Re: simulation vs. mimesis

[Judith Rosen <***>]

A model airplane either "simulates" or "models" the appearance of an airplane (without including much, if any, of the underlying causal entailment relations of the airplane in its own inferential entailments). If the inferential entailment relations between the model's external observables are not in any commutative relation with the causal entailment relations which exist between the airplane's external observables, then it's not a "model" in the sense we have been discussing; it is a "simulation".  The modeling relation doesn't commute. Which is my point: the modeling relation is A RELATION. So, the relation, as specified, is what determines whether something is a "model" or an empty "simulation"... How we define these things is context based (context perhaps being: What is the model supposed to do?) So the definition of "a simulation" is sometimes radically different from that of "a model" and other times they are synonymous. If the relations for "external observables" commute, but we want to model something about flight of an airplane, then the external-observables-model isn't a useful model. Again, the difference is based on contextual constraints.

 

Judith

----- Original Message -----

From: Tim Gwinn

To: ***

Sent: Friday, December 31, 2004 1:14 PM

Subject: Re: [ROSEN] simulation vs. mimesis

Judith,

 

JR:What I'm saying is that a simulation is still a model when the entailment structures of the external behaviors/observables are what are intended to be modeled (my example of the movie set and the storm).

 

What I am saying is that if the entailment structures are in congruence, then it is a model, not a simulation. How is a "model airplane" a simulation?? As I quoted, 'simulation' requires an extraneous machine on which the simulation runs, and which does not decode to something on the natural system side.

 

Regards,

Tim

 

-----Original Message-----
From: ROSEN Forum [mailto:***On Behalf Of Judith Rosen
Sent: Friday, December 31, 2004 11:03 AM
To: ***
Subject: Re: simulation vs. mimesis

Tim, there is more to entailment congruence between system and models than that-- it sounds like you are saying that a model has to model the whole entailment structure to be considered a model! This is not the case. How do you think humans have been able to get as far as we have, scientifically???

 

Yes, a modeling relation has the requirement of congruence between causal entailment in the system and inferential entailment in the model, but no model can include the system's entire entailment. All models are incomplete representations. This is simply the nature of the beast as far as human capacity to do science goes. The only big problem with it arises when humans forget that our models are incomplete representations of natural systems and we start making decisions based on predictions learned from our models for applications in the real systems. This is exactly what we are doing with genetic engineering of crops to be tolerant of herbicides, for example.

 

What I'm saying is that a simulation is still a model when the entailment structures of the external behaviors/observables are what are intended to be modeled (my example of the movie set and the storm). A model airplane, for example, has almost none of the underlying causal entailment of a real airplane. It's use as a model is limited to only a few practical applications: Like how to design an airport hanger to house the airplane if it is that design of airplane and the model is "in scale". What does "in scale" mean? It means that entailment relations in external observables are preserved, regardless of the different size. If the model is in scale, then those relations will commute with the relations present in the actual system (the plane).

 

A flight simulator is also a model, but not of the entailment relations of the external observables. It models other entailment relations. Do you see?

 

Judith