Dear FIS,
As usual, I am highly irregular in my contributions. I would like to make a
sporadic remark on quantum complexity. In my opinion, the quantum
measurement process is at the core of emergence of complexity in quantum
systems.
Suppose the instrument A is measuring the object B. B has a certain
complexity, and A, as a result of measurement, becomes more complex. Suppose
A is a photofilm, and B is the object of the photographer's interest. Before
the measurement A was simple (uniform). After the measurement B is encoded
in A, and A becomes non-uniform and therefore more complex.
In classical measurement A measures B. In the limit of infinitely
precise A it just becomes a replica of B and, therefore, as complex as B.
Thus classical measurement becomes in the limit exact.
In quantum measurement A measures the system of A and B, i.e. the
instrument is embedded in the measured object, is part of it. Here the
situation is more involved. A becomes more complex as a result of
measurement, and, concomitantly, so becomes the measured system, which is (A
and B). Therefore, as the measurement develops, A becomes more and more
complex. A measures (A and B), i.e. A in the process of measuring (A and B),
i.e. A measuring (A and B) and so on. However the measured system (A and B)
keeps ahead of it in complexity, because A is always part of (A and B). If
B, in turn, also measures (A and B), we have a steady increase in complexity
of A and B. A metaphor could be looking at one's self in the mirror, and
seeing the reflection of the mirror in one's eyes, and reflection of these
eyes in this reflected mirror, etc...
This recursion is not instantaneous but develops in time and, in my
view, represents a pretty good model for evolution. A cell mechanism A
adapts (measures) to the cell environment, which it is part of. During this
adaptation it increases its complexity and changes (by its very presence)
the cell environment, which thus also increases its complexity. Given that
there are many such mechanisms (enzyme catalyzed chemical reactions,
organelles, membranes, etc), each mechanism increases its complexity by
reflecting on the presence of the totality of the other mechanisms.
Hope anyone can understand this mess.
Igor
----- Original Message -----
From: "Pedro Marijuan" <marijuan@unizar.es>
To: <fis@listas.unizar.es>
Sent: Tuesday, December 13, 2005 5:13 PM
Subject: [Fis] quantum & bionetworks
> Dear all,
>
> In a recent essay by physicist Paul Davies (A quantum recipe for
> life --Nature 437, 6 Oct. 2005) there is a series of intriguing
> assertions:
>
> "Today the cell is regarded not as magic matter but as a computer
--an
> information processing system and replicating system of astonishing
> precision... to get life started all you need is to replicate
> information... Quantum Mechanics thus provides an automatic
discretization
> of genetic information [without the need for complex intermediate
> chemistry]... but how complexity emerges in quantum systems is a subject
> still in its infancy... the principles involved could be illuminated by
> applying algorithmic complexity to quantum information theory...
> [Unfortunately] molecular biologists are content with ball and stick
> models based on classical concepts...."
>
> Let me make a couple of comments, first, about the off-repeated vision of
> life a an "information processing system", which can also be
found
> literally in most leaders of systems biology ---e.g., Walter Gilbert,
> Leroy Hood, Hirachi Kitano. It is a truism in these new fields, that
> sensibly identify the subject with the technology used, but it is not so
> innocuous as almost automatically it leads to a number of misperceptions:
> the input / output scheme, the hardware / software separation (DNA as a
> program), the sufficiency of control theory, and also the idealized
> "neurodynamics" of behaviorism and functionalism, and all sorts
of
> life-as-mechanism doctrines (now in the more fashionable dressing of
> info-processing ). Well, it may be OK, or perhaps not so disastrous, in
> the context of particularized analysis, but as an overall integrative
view
> it means "flat thinking", a cul-de-sac for informational
schemes... And I
> should stop here, as I already referred to the subject in previous mails.
>
> Far more interesting (in my opinion) looks the approach to
> complexity-growth in the quantum realm. Personally, I am situated at the
> other side --hoping that new views on biological complexity and
> information will get an unexpected convergence with new quantum
> interpretations. As Michael Conrad argued in our Madrid conference (1996,
> BioSystems): "When we look at a biological system we are looking at
the
> face of the underlying physics of the universe." In Davies'
comments,
> however, one has to appreciate the criticism to molecular biology ball
&
> stick models. The biomolecule, I argued weeks ago, appears as caught in a
> very complex "production and functioning cycle" implying a
plurality of
> actions and codes, where the exclusive insistence on mechanistic parts or
> on a "central dogma" becomes close to a minimalist caricature.
>
> So, where to go? At the time being, let me argue, we cannot advance much
> along the really needed bioinformation synthesis without playing --very
> wildly-- with new ideas on molecular production/function cycles,
molecular
> recognition, heterogeneous networks, protein synthesis / degradation,
> minimal cellular complexity, cell cycles and checkpoints, cellular
> signaling systems, cell-fate specification, asymmetrical cell division,
> cell survival, organ and tissue development, physiological and neuronal
> circuits... Who knows whether the very bizarre panorama of today will
> find very elegant simplifications --every new synthesis appears so
> "natural" once it has succeeded!
>
> An important part of FIS agenda might hinge herein.
>
> Thanking the patience!
>
> Pedro
>
>
>
>
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Received on Wed Dec 14 16:31:46 2005
