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It must be that
organisms - as physical systems - have constraints...and some of them are
holonomic and some are non-holonomic. It is required so that organisms are
"held together" by forces rather than merely being blobs of statistically
congregated particles in some area of space, like a gas cloud. Whether the
non-holonomic constraints that are present are such in number that all
velocity variables of all the structural 'particles' of an organism are
determined by configuration alone is in question.
When I wrote my
post this morning, it seemed compelling to me that an organism could be a
maximally constrained system. Howard in his reply disagrees, and I thought about
it some more and maybe it is not so compelling. And the reason I am
reconsidering has to do with what Rosen called "structure-function
complementarity" in the paper.
If I adopt the view that an organism is not a maximally
constrained system, then what comes to mind for me is: if an organism's pattern
(for lack of a better word) of
behavior is not dependent upon forcing all velocity variables to be
determined by configuration, then what allows its pattern of behavior to remain
invariant despite the removal of some information (i.e., the removal
of momenta due to freezing) from the system? [Here I am using 'information' in a general sense, not
specifically referring to Howard's 'informational constraint'.]
My conjecture
would be: those momenta (of
the unconstrained 'particles') must not therefore constitute information relevant for the system's pattern of behavior.
In that case, it would appear to
follow that the dynamics of structure are not the relevant criteria. What I am now wondering is if the invariance
of behavior to the removal of all dynamics indicates that (at least some) of the
non-holonomic constraints that are present constitute a nexus of such
constraints which serves to keep the functional organization invariant. This
would be very difficult to describe in strictly structural terms, i.e. in the
usual formal representation for constraints in analytical mechanics, because we
don't have a good way to first represent biological "functions" in structural
terms onto which these constraints could then be imposed.
The result would
be that an organism is not maximally constrained structurally, but
is maximally constrained functionally.
That's my thoughts
for the moment anyway,
Tim
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