Commentary 05 on|
Karl Jaspers Forum, Target Article 19, 3 August 1999
Review of 'PHYSICS FROM FISHER INFORMATION'
By Chris Nunn
INFORMATION, PHYSICS AND ANIMAL SUBJECTIVISM
by Paul Jones
24 August 1999
Unfortunately, I haven't read Frieden's book, and I doubt I could
ever get it. Nevertheless, I feel that I have right to discuss its
contents, because it is not novel to me, and I read all that before,
in a different edition. As far as I can judge, Frieden reproduces,
with minor differences, the results obtained by Italian physicist
E.R.Caianiello, who worked on the same problem since early 50s .
It is up to historians of science to trace the relations between
Frieden and Caianiello they are not relevant to the theme of this
commentary. Personally, I have nothing against plagiarism, provided
it serves to bring something valuable to as many people as possible .
Attempts to somehow employ the notion of information in physics
are older than the very term "information". A historical review
in  traces them down to 1867 though I recall Hegel saying
something of the kind, and the ancient Pythagorean school could be
readily associated that line. However, one can rarely find a scientific
work that would recourse to information in order to solve a physical
problem proper (as in ) most likely, such works would
deal with philosophy rather than physics, trying to play on term
indeterminacy to advocate some kind of philosophical idealism.
One popular direction ascends to L. Szillard (1929)  trying
to find a direct correspondence between information and energy.
The corner stone of this approach, Landauer's principle , has
been discussed in tons of papers and books, as if it were something
well established and experimentally proven. Many scientists
have been seduced by the apparent simplicity of such a correspondence,
and there have been numerous attempts to refine theory to accommodate
information along with the other thermodynamic quantities. However,
no significant progress has been made, except designing numerous
sophisticated constructions designed to explain a number of mental
experiments. Modern thermodynamics can do well without information,
as it seems. It has entropy already, and another quantity of the
same kind would be excessive.
Ideas of a different scope originate from the universality of
variational principles in physics. Physicists are accustomed to
think that all kinds of equations of motion should be derivable
from action minimization, with appropriate action functional.
This approach is closely related to universal geometrization,
since the value of action functional can be treated as curve
length in a space of a certain kind. Fischer metric , obtained
from the functional of cross-entropy, which is also called
information, can be used to construct action functionals like
any other metric, and, choosing an appropriate form of the
density that enters the definition of Fischer metric, one
can obtain almost any result. This is how all physics gets
derived from Fischer information in Caianiello's and Frieden's
It should be stressed that variational derivations are little
sensitive to the exact form of the action functional used,
and the same equations of motion can be obtained from quite
different variational considerations . Even with the same
Lagrangian approach, all Lagrangians differing by the full
derivative of any function of coordinates and momenta produce
the same equations of motion; also, a Lagrangian can be
multiplied by the full derivative of any function vanishing
on the boundary, without changing the equations of motion
obtained this essential arbitrariness is often used to
express the variational principle in a simpler way .
One can easily comprehend it, recalling that there can be
uncountably many functions on the interval [a, b] possessing
minimum in a fixed point x between a and b the more so
for functionals taking their minimum on a certain function class.
The two ways of introducing information in physics are not
entirely uncorrelated. Thus, since Lagrangians can be
represented as the difference of kinetic and potential energy,
one can employ proportionality of energy and information to
obtain the same Lagrangian as the difference of "actual"
and "potential" information, like in the Frieden's case.
Astonishingly, why many people tend to associate inequalities
of the Kramer-Rao type with quantization. The famous Heisenberg
relations of quantum mechanics are merely a special case of
a general principle valid for any wave motion, and, in particular,
applicable to acoustic waves, tension waves, gravitational waves
on water surface etc., which are all classical, as well as
classical optics, which used such relations for centuries,
and which lent them to quantum physics as a kind of metaphor.
The appearance of such limiting inequalities in measurement theory
is also quite natural, and one can develop an entirely physical
interpretation involving no characteristics of the observer other
than physical .
It is quite admissible that people try various conceptualizations
and get engaged in intellectual play of any sort. However, a sound
person will always distinguish such play from what can be actually
done in the world, and it is in application to practical problems
that formal constructions become justified. As long as Landauer,
Caianiello or Frieden speak about just another approach to
theorizing in physics, this is a physical study like any other,
and it certainly has right to exist. The development of physics
will show which parts of these conceptual constructions can be
used to describe physical systems, and what in them is not feasible
enough. It is also quite natural that, in the first (syncretic)
phase of its development, any physical theory has to seek for
substantiation other than that provided by applications, and new
directions of research are bound to be guided by philosophy.
One could only regret that this is not always a philosophy of a
better sort and it is shame for the society that makes scientists
advertise their results by ascribing them an inappropriate
philosophical background just because such a philosophy is
more socially acceptable. Definitely, is Frieden had not felt
that presenting the human mind as the source of reality would
promote his theory better, he would have well done without any
conscious observer, staying within the objective framework he
was used to in his image recognition studies.
As D.Lindley has clearly expressed it , all physical problems
can be solved using physical means, and there is no physical situation
that would require conscious intervention being included in the
description. Any recourse to the mind of the observer drives
consideration out of physics to some other science, or philosophy.
One could consider the apparently physical influence of a distant
star on the course of a ship, mediated by a human navigator
however, such a consideration would refer to the interaction of
different levels of material motion, rather than be restricted to
the physical level only; physics can be engaged on the extremes of
the mediation chain, in explaining the positions of stellar bodies
and light propagation, or the mechanics of rudder declination
physics has nothing to do with the people's intention to move in
a preferred direction. One could trace the influence of physics
on mentality, rather than the other way round. Trying to derive
physics from consciousness is like to assert that the motion of
the centre of mass of the system of two bodies is the cause of
their individual motion. That is what M.Szirko characterized
as putting the cart before the horse .
As for the ways of subjectivist re-interpretation of physical
theories, one could find term substitution to be a basic mechanism.
Physicists (and other scientists) use many common words in a
terminological meaning, which can be entirely different from
their meaning in the ordinary language. Thus, it would be
naive to literally understand such physical terms as flavor,
color, spirality, frame etc. The same care should be exercised
about such terms as force, energy, entropy, signal etc. I admit
that it might be difficult to always remember that the words like
space, time, particle, interaction, measurement, observation etc.
can only be physically meaningful within certain physical theories,
having little in common with the everyday word usage. Also,
information, as it may enter a physical theory, will have a meaning
different from that of other sciences, or philosophy, or ordinary
language. The persistent prejudice that the content of a message
may be "measured" with the quantity of information as defined in
systems theory is due to illegal term identification; some
handbooks on mathematical information theory clearly indicate
that they deal with a specific quantity that does not have all
the connotations of the ordinary word [13; 14, ch.5]. It should also
be noted that the well-known Shannon information (or Fisher
information related to it) is only one of the many measures of
uncertainty, indeterminacy, nonspecificity, fuzziness etc. .
One has to be careful in applying one of those measures to a
problem of a certain level (physical, biological, social), selecting
a measure that would adequately describe the system under
consideration. Beside the quantitative measures, there are
also various qualitative aspects of information , and one
could also consider creative communication, which can in no way
be described by the parameters of the physical signal .
When a physicist speaks of an observer, no human observer is
meant the term is a mere abbreviation for a certain physical
situation, when a number of physical bodies can reflect the
motion of the system "observed" without too much perturbation
in their own motion. The meaning of "too much" depends on
the level of description. A heavy particle, or a plasma cell,
can be an "observer" of an electron as readily as a human being,
from the physical standpoint. The act of "observation" can be
specified in purely physical terms, without any recourse to
consciousness. It is only poor philosophers who identify this
metaphorical usage of the word with a reference to a conscious
being on the same grounds, one might claim Maxwell's demon
to be a kind of human being, with superhuman capabilities!
No need to repeat the same for "measurement", or "information".
Originally, all the words are anthropocentric, and the ability
to overcome this innate anthropocentrism is one of the greatest
achievements of science. One has to go beyond mere experiences
to get knowledge, and the socialization of the ways of handling
external things is the only instrument for that. An idealist
may be convinced that he/she produces anything (whatever it can
be: a car, a painting, a scientific theory or philosophical
treatise) merely for amusement, without any thought of the
others this is either lie or delusion, since everything
people do is designed to be used by other people (which may or
may not include the author), and this is what distinguishes
humans from most animals, who can do something for the other,
but only in certain cases, not universally. Well, one can
lose that universal social orientation of activity this
would mean the loss of consciousness and reason as well,
degrading to the animal state. Unfortunately, in a poorly
organized society, many people get compelled to behave that
way, competing with each other and robbing each other of the
human appearance. This is the worst kind of violence, since
it kills the spirit, the very ability to be human.
Subjectivistically minded people are like animals, their
minds are too weak to penetrate the barrier of their immediate
experience, and eventually they refuse to try. For an animal,
everything occurring between the animal's action and the
sensory input is absolutely irrelevant, since the animal's
"mind" is centered on the animal itself, its well-being and
sensory ease. The same holds for certain sorts of people,
Experimental study of animal conditioning has shown that there
is a phenomenon called hyper-generalization: when an animal
has a positive experience, it tends to associate it with
the current situation in a syncretic way, including its both relevant
and irrelevant aspects. It is much later, with repeating instances
of confirmation and discourage, that the animal learns to
recognize the relevant stimuli among the rest of experiences.
Thus, a cat who has caught a mouse in the corner will look for
a mouse in the same corner for quite a while, though there may
be no trace of the mice frequenting the place.
When Frieden (and the army of subjectivist philosophers) argues
that, since all we measure in a physical experiment is a
response to the act of measurement, all Nature may be nothing but
a response to some conscious act, they employ the same syncretic
reasoning and shy materialists like Nunn have to invent
something like time loops to avoid the ghost of god arising as
a response to such an inadequate generalization... A scientist
(and every layman) understands that any experimenting makes sense
only if the experiment triggers some natural process in the same
way as it gets triggered in industry, or in natural circumstances
otherwise, the experiment would be justly criticized as improperly
staged. The ability to analyze what occurs between one's action
and the environment's response to that action is a distinctive
feature of humans as conscious beings.
The logical analogue of hyper-generalization could be illustrated
by the following examples:
Theorem: The sine is an even function.
Proof: Indeed, sin(π)=sin(-π); consequently, the sine is even.
Theorem: All the odd integers are primes.
Proof: 1 is a prime, 3 is a prime, 5 is a prime, 7 is a prime...
Obviously, every odd integer is a prime.
Women: All men are villains, 'cause I knew one...
Men: All women are stinkers...
Philosophers: Anything I observe is certainly my observation.
Consequently, anything in the world is nothing but my observation.
This scheme is known as empirical induction, and it may be useful
to generate hypotheses, but it certainly cannot be used in an argument.
- There is nothing wrong in that Caianiello, Frieden, or anybody else
tries to employ the notion of information (or, rather, one of the
possible formalizations) in physics. Physical theories are flexible,
and they allow various interpretations, some of which may be more
suitable than the others.
- Any attempts to introduce information in physics must be
consistent with the physical methodology, and they should not
refer to consciousness (or any other phenomena of a different level)
to explain the dynamics of a physical system.
- The attempts to interpret physical results in a subjectivist way
have nothing to do with physics, and, in general, they are politically
- The logic of subjectivism is nothing but reduction of conscious
reasoning to the primitive forms similar to those observable in
1. E. R. Caianiello "Quantum and Other Physics as Systems Theory" La Rivista del Nuovo Cimento, v. 15, no. 4 (1992)
3. Maxwell's Demon: Entropy, Information, Computing (H. S. Leff and A. F. Rex, eds.) (Princeton, NJ: Princeton Univ. Press, 1990)
4. R. B. Bernstein and R. D. Levine Adv. At. Mol. Phys., v. 11, 215 (1975)
5. L. Szillard, Zeitschrift f. Physik, v. 53, 840 (1929)
6. R. Landauer, IBM J. of Research and Development, v. 5, 183 (1961)
7. R. A. Fischer, Philos. Trans. R. Soc. London A 309 (1921)
8. V. V. Dobronravov, Foundations of Analytical Mechanics (Moscow: Vysshaya Shkola, (1976)
9. L. D. Landau and E. M. Lifschitz, Mechanics (Moscow: Nauka, 1973)
10. M. B. Mensky The Path Group: Measurements, Fields, Particles (Moscow: Nauka, 1983)
11. D. Lindley, KJF TA19 Commentary 1
12. M. Szirko, KJF TA19 Commentary 4
13. H. J. Flechtner, Grundbegriffe der Kybernetik (Wissentschaftliche Verlagsgesellschaft, 1966)
14. G. J. Klir and T. A. Folger, Fuzzy Sets, Uncertainty and Information (Englewood Cliffs, NJ: Prentice Hall, 1988)
15. M. Mazur, Qualitative Information Theory (Moscow: Mir, 1974)
16. P. Ivanov,
"Art as creative communication",
Interaction between Man and Culture: Information Standpoint Proceedings of the International Symposium (Taganrog, Russia, 1998),
v. 1, pp. 95-100