DOES AN OBSERVER BELONG IN PHYSICS?

                                            JAN NOVOTNÝ

Abstract: In this paper we comment on the opinions of great philosophers from various epochs on the
relationship between computers and the human mind. We ponder over whether we might be able to gain
an understanding of the human mind and a perception of the world from the scientific point of view.
We focus on the relationship between these two issues.

Keywords: computers, understanding, human mind, observer, natural processes


Introduction


            The title of the conference is “Computers, or pencil and paper?” As a theoretical
physicist I am used to using both, so in my mind the question becomes: computer or “head”? Does
relying on a computer mean that the “head” loses human qualities such as understanding and insight?
Computers are becoming more and more capable—will they ever converge with the human mind? Will
computers ever become, as Alan Turing (Turing, 1950) once dreamt, our equal partners?

            Even this question is starting to appear to be a part of an even bigger problem: is it
possible that in the future human beings will be understood and explained as a natural part of
nature, fully subjected to natural laws, as we understand them in contemporary mathematics-oriented
science?

            These questions are not new and to gain a deep understanding of them would be a never
ending task. Hence, I will concentrate only on four steps, as if I were walking through a gallery
and have chosen only four key paintings. I would like to use them to demonstrate how the same
problems reappear again and again, their essence unchanged, even though the technology is
increasingly advanced.


The first stop:  The senses and the mind


            The first attempts to explain natural processes on the basis of particle physics and
the formulation of the laws of particle behavior were undertaken by ancient Greek thinkers. Their
efforts culminated in Democritus’ teaching (Democritus A14, 1948), postulating that the world is
composed of atoms which move within unlimited space. The interaction between these atoms causes
everything else.


            How can we know atoms exist and can our mind influence the way they move? Ancient Greek
thinkers did not avoid this question. Lucretius’ writing (Lucretius (2011)) is proof of this. His
writing combines poetry, science, and philosophy in a way which could not have been achieved later.
Lucretius states that everything in this world is connected to the law of cause and effect. Thus
the question arises:


Whence this free will for creatures o'er the lands,
Whence is it wrested from the fates,- this will
Whereby we step right forward where desire

            Lucretius develops this theme of the free will of all beings in many intriguing scenes,
and then he concludes succinctly:


… this state comes to man
From that slight swervement of the elements
In no fixed line of space, in no fixed time.


            Lucretius was using Epicuros’ idea of trying to correct the original strict determinism
of original atomic theory, which would have meant all freedom was an illusion. Even if the
possibility of freedom emerges, we still do not know how to approach it. How can the movement and
interaction of atoms which make up our bodies be transformed into a human perception of the world
and how can we direct the randomness of these movements so that we can achieve our goals?

            Five centuries later, Claudius Galenus (Galenos B 125,[INS: :INS] 1948) identified the
problem of atomic theory:

Democritus, when he had run through the senses (saying 'by convention colour, by convention sweet,
by convention bitter: in truth, atoms and the void'), then portrayed the senses by speaking to the
intellect as follows: 'Wretched mind, do you take your evidence from us and then overthrow us? Our
overthrow is your fall'.


            As all good doctors are, Claudius Galenus is capable of having a deep understanding of
the scientific and human site of things. Through our senses we have access to knowledge, which is
then processed by our mind. Our mind awakens a desire for unbiased knowledge, which should be
expressed using scientific language and accessible to all investigators. We do not then trust data
obtained by our senses that does not comply with these requirements. What will we be left with if,
on the one hand, we set strict requirements of objectivity and, on the other hand, belittle the
vague testimony of our senses? The mind without the support of the senses would become an isolated
island, incapable of understanding its own existence and its destiny in the world, accessible only
through senses.



The second stop: Machines, free will, and the mind


            After thousands of years of lethargy, interest in a scientific understanding of nature
is awakening again. Galileo Galilei (Galileo, 1960, p. 237) outlines the major methodological
principles:


“Philosophy [nature] is written in that great book which ever is before our eyes -- I mean the
universe -- but we cannot understand it if we do not first learn the language and grasp the symbols
in which it is written. The book is written in mathematical language, and the symbols are
triangles, circles and other geometrical figures, without whose help it is impossible to comprehend
a single word of it; without which one wanders in vain through a dark labyrinth.[INS: ” :INS]


            Galileo's attempts to postulate a comprehensive theory of natural phenomena is nicely
summarized in the book The Assayer. These attempts may have been the main reason why the clergy
were concerned—they were afraid people might conclude that God does not intervene in the world's
affairs (White, 2007). Galileo writes (Galileo, 1960, p. 277):


To excite in us tastes, odors, and sounds I believe that nothing is required in external bodies
except shapes, numbers, and slow or rapid movements. I think that if ears, tongues, and noses were
removed, shapes and numbers and motions would remain, but not odors or tastes or sounds. The
latter, I believe, are nothing more than names when separated from living beings, just as tickling
and titillation are nothing but names in the absence of such things as noses and armpits.


            Galilei follows an approach similar to the one Claudius Galenus challenges in
Democritus' teaching. Interestingly enough, and contrary to Democritus, Galilei does not include
eyes and colors, or more widely, the perception of light, in his statement. He understands how
important light is as a source of information and he suspects that light phenomena are more likely
to be converted into shapes, numbers, and movements (later described in physics as waves,
amplitudes, and frequencies).


            The first calculating machines—mechanical calculators—were built in the 17^th century.
Surprisingly enough, one of their first designers, Blaise Pascal, organized  their mass production
for some time. In Pensées he devotes but a single, yet very serious, sentence to them (Pascal
Sec.VI/340,XXXII, 1958):


The arithmetical machine produces effects which approach nearer to thought than all the actions of
animals. But it does nothing which would enable us to attribute will to it, as to the animals.


 René Descartes mentions a similar problem in his Discourse on the Method. He writes (Descartes,
1998, p. 114):


Machines which had organs, and the exteriour figure of an Ape, or of any other unreasonable
creature, we should finde no means of knowing them not to be altogether of the same nature as those
Animals: whereas, if there were any which resembled our bodies, and imitated our actions as much as
morally it were possible, we should always have two most certain ways to know, that for all that
they were not reall men.


            For Descartes, the boundary between minds that are able to think and minds that are not
is located in a different place than for Pascal. According to Pascal people belong to the same
category as animals, which Lucretius calls creatures. According to Descartes only people are able
to think. Let us hear why Descartes thinks even machines that perfectly imitate human abilities
would not be the same as humans. (Descartes, 1998, p. 115)



The first of which is, that they could never have the use of speech, nor of other signes in framing
it, as we have, to declare our thoughts to others…


            Today we would probably consider this argument non-valid since computers nowadays not
only use words and characters, but they use languages too. But the second argument is still very
relevant. (Descartes, 1998, p. 116)



And the second is, that although they did divers things aswel, or perhaps better, then any of us,
they must infallibly fail in some others, whereby we might discover that they act not with
knowledge, but onely by the disposition of their organs...


            According to Descartes, perception and will are not sufficient attributes of
intelligence, only the intelligent mind as a universal tool is. The absence of perception and will
results from the absence of an intelligent mind. We can complete Descartes' thought: [INS:
creatures :INS]  composed only of organs base their acts on the laws of nature, they have no mind
of their own since they do not need one. If we consider machines or [INS: creatures :INS]  from the
standpoint of a scientist, then they became simple machines or things  with no mind or will.


The third stop:  Apparatus, measurement, observer


            In his Mathematical Foundations of Quantum Mechanics, John von Neumann (Neumann (1996))
simply, but thoroughly, analyzes how essential the role of observer is in physics. He illustrates
this using an example: When we measure temperature we can conclude the process by measuring the
temperature of the air around the flask using mercury and state that the temperature was measured
by the thermometer. We can include the length of the column of mercury and say that the length was
recorded by the observer. We can add that the light traveled from the thermometer to the observer's
eye and produced an image on the observer's retina. Given sufficient scientific knowledge we could
research how the chemical signals traveled to the brain.  But in any case, Neumann's conclusions
(Neumann, 1996, p.77):

 will still be true:


That is, we must always divide the world, into two parts, the one being the observed system, the
other the observer. In the former, we can follow up all physical processes (In principle at least)
arbitrarily precisely. In the latter, this is meaningless.


That this boundary can be pushed arbitrarily deeply into the interior of the body of the actual
observer is the content of the principle of the psycho-physical parallelism — but this does not
change the fact that in each method of description the boundary must be put somewhere, if the
method is not to proceed vacuously, i.e., if a comparison with experiment is to be possible.


            Before the end of the 19^th century, the observer was almost never considered to be of
any importance. It was assumed that the analysis of a physical process ends with reading a
measuring device and that this reading is not dependent on the observer. With the gradual
perfection of scientific devices and the statistical evaluation of data we come ever closer to this
reality.


            Thanks to the theory of relativity and quantum theory, the word “observer” appeared
frequently within the science of physics during the 20^th century. But these two examples are very
different. Using “observers” makes the concepts of the theory of relativity much easier to explain,
and observers could easily be substituted with measuring devices. When objects travel in high
velocity and great amounts of energy are involved, the results of measurements are considerably
different than one would expect given the classical teachings (distance contraction, time
dilation). The situation is even more complicated in quantum theory and has yet to be successfully
clarified. Let us consider an excerpt from Landau and Lifshitz’s famous Course of Theoretical
Physics (Landau & Lifshitz, 1977, pp. 21-24):


We consider a system consisting of two parts: a classical apparatus and an electron (regarded as a
quantum object). The process of measurement consists in these two parts' coming into interaction
with each other, as a result of which the apparatus passes from its initial state into some other;
from this change of state we draw conclusions concerning the state of the electron.

…

The classical nature of the apparatus appears in the fact that, at any given instant, we can say
with certainty that it is in one of the known states.

…

We see that the measuring process in quantum mechanics has a "two-faced" character: it plays
different parts with respect to the past and future of the electron. With respect to the past, it
"verifies" the probabilities of the various possible results predicted from the state brought about
by the previous measurement. With respect to the future, it brings about a new state (see also
§44). Thus the very nature of the process of measurement involves a far-reaching principle of
irreversibility.


            The authors avoided talking about the observer directly. Observers can choose what they
are going to measure. Their decisions and preparations concerning the experiment are not subject to
physical analysis. As soon as the experiment is set up, the observer is there only to record the
data.  He/she cannot influence nature's answer to the question.


            Unlike in classical physics the answer to this question cannot fundamentally be
predicted. Quantum physics formulas describing the changing status of quantum objects can only
predict  the probable condition of a classical instrument in interaction with quantum objects.
These formulas do not explain how the instrument selects from different conditions—reduces data.
There is no clear definition of “classical”. Classical physics is not an extreme case of quantum
theory, but it is a fundamental condition necessary to prove quantum theory.


            Now the question arises as to whether the seemingly haphazard reality detected by
measuring was created by the measuring or if it existed beforehand and somehow predetermined the
outcome. Einstein and his coworkers defended the second opinion in their dispute with Bohr. The
importance of the work they conducted in 1935 was recognized much later, when it lead to the
definition of quantum entanglement (Einstein, Podolsky, Rosen, 1935).


We are dealing with the relationship between data obtained in different locations where there is no
possibility of one measurement influencing the other—for instance if superluminal speed (which is
impossible in terms of modern physics) was involved. This connection could exist if the objects
measured shared a mutual history. If I discover I have packed only my right shoe, it is pretty
obvious that the shoe I left at home is my left shoe. To the eccentric philosopher who would object
that I can only be sure that the shoe is the right one after I have looked at it (Berkeley’s “esse
est percipi”), I can argue that if my wife sees the shoe I left at home, I can predict with
certainty that she will see my left shoe, even though my looking at my right shoe could not have
influenced what she sees. The shoe was a left shoe before my wife looked at it; likewise my right
shoe was a right shoe before I looked at it.

            Einstein and his colleagues tried to point out that quantum theory is unsatisfactory
when applied to quantum objects that are entangled by their common history. They assumed that
physical interactions travel at a finite speed. So despite the fact that the measurement taken of
an object at location A cannot influence the measurement of an entangled object at location B we
can predict the outcome of measuring at location B on the basis of the measurement at location A.
Einstein concludes that an “element reality” localized in space exists and predetermines the
outcome of measuring at location B.

Even though the quantum mechanics uncertainty principle holds that the values of two variables
cannot be predicted at the same time, they can both be predicted. So the “element reality” which is
outside the scope of quantum mechanics, exists for each of them even before it is measured. John
Bell’s theoretical reflections and his associated experiments showed that the world is not governed
by Einstein’s assumptions. By comparing measurements of entangled objects it could be shown that
reality and location, in the sense Einstein understood them, are irreconcilable.


            It seems that the outcome of an interaction between a quantum object and a classical
measuring instrument is not preceded by any predetermining reality. On that basis we can
legitimately ask if the reduction is carried out by the instrument or the observer's mind.


The fourth stop:  Towards a theory of everything


            During the last few decades the dream many great physicists have had of the possibility
of formulating a universal theory of physics explaining all relationships among all physical
phenomena has come to fruition. This Theory of Everything is usually understood as encompassing all
four known interactions: strong, weak, electromagnetic, and gravitational. The main obstacle seems
to be that the theoretical foundation for explaining gravity is the general theory of relativity
based on classical concepts, and it is very difficult to connect it to quantum theory, which is
applicable to the remaining interactions.


The Theory of Everything might even have greater ambitions—it could include systems of considerably
larger complexity, including the human brain. That is how Roger Penrose, among others, understands
this theory. In his books (Penrose, 1989, 1994) he points out that the main obstacle to formulating
a universal theory is not only the fact that the general theory of relativity occupies an isolated
position among the other theories, but he also points out the contradictory character of quantum
mechanics, which does not allow a satisfying bridge to be constructed between quantum and classical
physics. Only once the bridge is built will we be able to understand brain processes and
incorporate consciousness and the intelligent mind into physics.


From that point of view, Penrose asks to what degree can modern computers actually “think”
(Penrose, 1997). He argues, and provides examples, that computers cannot understand and comprehend
the world the way humans can. Let me give you at least one example: a computer program called Deep
Thought capable of winning against champions. The program chooses a simple winning move connected
with material gain, because the catastrophic outcome would have surfaced after dozens of moves and
the program would not have calculated its moves that far. But even when a computer wins over a
human being it does so through “brutal force”—a computer can only do what people following
instructions would be able to do if they were not held back by their inability to act faster.


According to Penrose, the conscious mind can never be substituted by computing—when an algorithm is
followed. The fundamental attribute of the conscious mind is non-computability and Penrose believes
that the theories capable of overcoming the contradictions of quantum mechanics will have the same
attribute. But computability is not the same as mathematical science or determinism, and so it is
potentially possible (according to Penrose) to understand the conscious mind within mathematical
science. (Penrose, 1997, p.146):


I simply do not see any room for conscious mentality within our present-day physical world-picture
- biology and chemistry being part of that world-picture.


Conclusions (which I do not wish to force on anyone)


            Computers can execute our programs, but they cannot think for us. What computers and
people excel in is complementary, to some degree, and therefore it is important to combine these
strengths. We should always keep developing strengths that can never be replaced by the computer:
our intuition, ability to estimate, our understanding, and empathy. It is still good to know how to
calculate integrals and solve differential equations, even though a computer can do it much faster.

[INS: k :INS]           Pascal's thoughts and the second of Descartes' reasons are still true.
There is no evidence that even the most powerful computers have any will of their own and that they
have anything that people could not understand (as is the case with human conscience and the mind).

            Galen’s words are still valid: if we rid the world of everything subjective we will
have an incomprehensible world.

            Reflections on non-computability might lead to an understanding of conscious mind, but
like Lucretius' element deviations—they do not really show us how to approach this problem.

            I would like to try to answer the question: “Does an observer belong in physics?” Well,
on the one hand, yes, and on the other, no. Without an observer there would be no physics, but
physics does not explain the observer (now and maybe for ever). Perhaps we can say that an observer
forms the boundary of physics.


Acknowledgment

The author would like to express his thanks to Jindřiška Svobodová for her interest and
discussions, which helped to achieve more precise and clearer formulations.



References


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Faculty of Education,

Masaryk University,

Poříčí 7,

603 00 Brno

Czech Republic

E-mail: novotny@physics.muni.cz