|
Hallelujah! Thank you, Tim!
I think, however, it might be worth discussing whether organisms
are also "maximally non-holonomically constrained" systems or not. The more I
consider the nature of organization and how it creates context, the more I
see that non-holonomic constraints are actually a possibility
engine.
When this thread first came up, it was presented as if my father
was actually saying that, and I knew the only way he could have said
it, which would be consistent with his belief structure, was if
there was some aspect to it that created more possibilities than it limited.
Hence, it seemed quite reasonable to interpret the language such that "maximal"
is to "maximized" what "optimal" is to "optimized", and that may still be the
case-- he used the word that way in conversation. It became apparent, as more of
the paper was included, that the argument was a moot point; he was talking about
how a machine could mimic an organism.
The more I have researched the range of what can be defined as
a "non-holonomic constraint", though, the more I realize that the whole phrase
represents a situation in a system where the potentials are the most highly
developed (maximized). I regard anything that interacts with a system in any way
that causes change as "a constraint". Certainly, from that vantage
point, non-holonomic constraints in system organization generate more
potential than no constraints at all.
That fascinates me because it is, as my father would say;
"counterintuitive".
----- Original Message -----
Sent: Wednesday, November 03, 2004 9:46
AM
Subject: Re: [ROSEN] Maximally
constrained
After re-reading the paper, I think I agree
with Judith here. (I admit I did not clearly see this before re-reading.) He
carefully writes around any assertion that an organism
actually is a maximally constrained system. We do not know that
they are in fact maximally constrained system. Rather, he argues that we do
not know what organisms are, but only what they are like. I
would liken it to a reverse-engineering problem where we do not know about how
it was put together in order that it became an organism, we can
instead only make conjectures about its construction and organization by way
of comparing its known properties and behaviors with properties and
behaviors of other known physical or formal systems such that we will
hopefully gain some insight into what an organism is; without drawing the
further conclusion that if an organism can be like
some other system in some ways, then an organism is in
fact an instance of such a class of system. Such a conclusion
would require extensive and conclusive evidence. In this paper, his
focus is on how organisms can be likened to machines, and what are the
ramifications of such a comparison.
The paper begins:
"No one knows or can express what an organism
is. The best we can do is to try to do say what an organism is
like. For at least the past four hundred years, the pervasive
metaphor in biology has ben that of the machine. However, no one can say
what a machine is either; or rather, many people have said many different
things over the years; things which are inequivalent or even mutually
contradictory....Machines themselves have been variously considered as
physical or material systems, as the executors of specific functions, and as
mathematical abstractions. The remarks which follow are intended to clarify
the sense (if any) in which the organism is like a machine; in the process,
we may hope to learn some new things about both; about the extent to which
machines can be considered lifelike, and to which organisms are
machine-like." [p.107, ital orig]
I think that the quote Howard
provides...:
"The results of our
analysis above suggest that, whatever else may be true of relatively simple
but nevertheless highly evolved contemporary cells, they must at least
behave physically like maximally (nonholonomically) constrained,
programmable mechanical systems." [p.122, ital
org]
...which is immediately
followed by...:
"Therefore, it appears
that a sensible strategy along these lines is to attempt to fabricate such
a system artificially. This would at least give us a conceptually
well-defined end-point to aim at." [p.122]
...demonstrates the
caution Rosen is using. If behaviorally organisms act like maximally
constrained systems, then a logical next step in the comparison process would
be to move from a mathematical argument to an empirical study: to try to
construct such a system. Then we would know more about the requirements for
constructing such system, how such systems work physically and how well
these physical realizations compare (or don't compare) to
organisms.
I think the mathematical argument that
organisms are in fact instances of maximally constrained systems is
compelling. But it remains unproven empirically to this day; therefore,
conclusions drawn from comparisons between the mathematical conclusions
and organisms can be equally compelling, but do not serve as
proof. I think that Rosen is making a similar - if subtle
- distinction between compelling and unproven.
Regards,
Tim
> -----Original Message-----
> From: ROSEN Forum [mailto:***]On
Behalf Of Judith
> Rosen
> Sent: Tuesday, November 02, 2004 4:56
PM
> To: ***
> Subject: Re: Maximally
constrained
>
>
> He was referring to a machine, as
Tim pointed out in his first
> post on this
> whole
discussion:
>
> > Tim Gwinn wrote: Rosen later notes that
this is the only kind of
> mechanical system which can accomplish the
experimental result
> that Morowitz
> pointed out years earlier:
that a bacterial cell could be carefully frozen
> to absolute zero
(where all dynamics (all momenta) are removed) and then
> re-thawed
(with no real control over the specific imparted
> momenta) and
the
> cell could continue to grow.>
>
> My father was not
talking about the bacterial cell being a "maximally
> etc....." but
rather the only kind of machine that could appear as if...
>
> It
is the machine that he referred to as having the "maximal number of
>
non-holonomic constraints".
>
> Judith
>
> > Howard
Pattee wrote: On p. 414 of Anticipatory Systems, Rosen points out
> that
informational constraints are not a part of Newtonian mechanics but
>
"can be regarded as arising out of [Newtonian mechanics] by the
imposition
> of a sufficient number of non-holonomic constraints." The
only problem I
> have is why "a sufficient number" has become "maximal
number.">
|