|
Jack Park wrote: From my, possibly naive, Rosennean view, it seems to
me that the entailment structures map to each other.
Once again, it matters what you want "the model" to do. If you want
a rough commutativity between the real airplane and the model such that thrust
plus wingshape, plus ? equals, whatever... then you have a modeling relation. I
was thinking about the kinds of things like pilot inside airplane, small
moving parts in engine and flammable fueltanks on board, passengers and luggage
and the exigencies of how to balance all that such that you can still become
airborne and remain stable, the density of atmosphere at whatever altitude the
plane is supposed to fly, how to compensate for thin atmosphere inside the
cabin, what safeties are in place for various weather conditions, etc... none of
which are engineered into the toy airplane. It's different, contextually. It
models some aspects of airplane flight, but simulates others. How's
that?!
Judith
----- Original Message -----
Sent: Friday, December 31, 2004 1:28
PM
Subject: Re: [ROSEN] simulation vs.
mimesis
Model airplanes of the radio-control type. I own those. Judith
said:
<quote>
The causal entailments of an airplane (which
constitute the "guts" of an
airplane's functionality) are not present in
the model...
</quote>
Say what?
Let me enumerate my
view of the functionalities of an airplane, be it a
model or one you climb
in and fly (I built those too). They are:
overcoming drag
forces
overcoming gravitational forces
Now, in my, possibly naive,
Rosennean view, drag forces are entailed by
a body moving through a fluid,
such as air; gravitational forces are
entailed by the mass that is the
airplane, whether model or "real".
Drag entails thrust. Thrust entails
a thrust-producing device, be it a
propeller-with-engine, or jet or
rocket, (or rubberband slingshot, as in
some models). Lift entails lifting
devices, typically called "wings",
which are known to have airfoil shapes
which entail pressure differences
between the upper and lower surfaces,
those pressure differences
entailed by the motion of air over the surface,
whether that motion is
the air moving over the surface or the surface
moving within a mass of
air. It's all relative, I suppose.
So,
building a model airplane (mine are mostly gliders, some with gas or
electric moters to launch them to appropriate altitudes), I install
wings, tail feathers, and motors, plus electronics and servos for
controls. That all adds weight, so, again, gravity is entailed, and lift
is required. Moving that mass around in air entails drag, requiring
thrust. Some thrust can be provided by a propulsive force, and some can
come out of a vector analysis of the forces entailed by a wing moving
through an air mass while descending (gliding).
From my,
possibly naive, Rosennean view, it seems to me that the
entailment
structures map to each other. The primary differences being
those related
to scale effects, known as Reynolds number effects; that
is to say, the
lift-to-drag polars of a model will not be anything near
as "good" as they
are with a "real" airplane.
So, how can you
say
<quote>
However, even there I would suggest that the reasons
why the toy
airplane is able to fly are mostly not the same as the reasons
the real
airplane is able to fly. The entailment structures don't commute
very well.
</quote>
Inquiring minds want to
know...
Jack
Judith Rosen wrote:
> *That's OK, Howard,
that's what makes horseraces.*
> **
> *Sometimes it's important
to "play devil's advocate" and show how
> aspects of Yin are
embodied/entailed-by Yang, and vice versa. Otherwise,
> we might forget
and become hidebound-- not a good thing to become.*
> **
>
*Incidentally... I would argue that the causal entailments of an
>
airplane (which constitute "the guts" of an airplane's functionality)
>
are not present in the model. However, the model I have in my mind's eye
> is a little plastic one like the ones that my brother used to build
from
> a kit, with modeling glue, and it only "looked like" an
airplane. It was
> perfectly hollow and if you tried to make it fly, it
tended to plummet
> and break into a zillion pieces. You may be
imagining a model airplane
> that is a remote-controlled flying toy
airplane...*
> **
> *However, even there I would suggest that the
reasons why the toy
> airplane is able to fly are mostly not the same
as the reasons the real
> airplane is able to fly. The entailment
structures don't commute very
> well. So the flying toy may be a useful
model for demonstrating what
> happens to a real airplane when
interacting with a downdraft, perhaps,
> or some other application
where the missing entailment structures don't
> impact the outcome...
*
> **
> *We need to remember, though, that all of these airplane
and model
> examples are still dealing with "machines"... simple
systems. When we
> are dealing with new territory, like relational
models of complex or
> complex/living systems, it is wise never to make
that assumption (that
> the missing entailment structures won't impact
the outcome).... and I
> would side with Tim, in that case, myself.
*
> **
> *(But my reasons for doing so are different!)*
>
****
> *Judith (the-devil-made-me-do-it) Rosen*
> /PS: Happy last
day of the year, everybody!/
>
> -----
Original Message -----
> *From:* Howard Pattee
<mailto:***>
>
*To:* ***
<mailto:***>
>
*Sent:* Friday, December 31, 2004 2:43 PM
>
*Subject:* Re: [ROSEN] simulation vs. mimesis
>
> Judith,
>
> I have to side with Tim. A model airplane has
the basic causal
>
entailments
> of an airplane. It flies. A
simulator doesn't. This is an important
>
distinction.
>
>
Howard
|