How to
Teach Physics in an Anti-Scientific Society
Herbert Pietschmann
Institute for Theoretical Physics
University of Vienna
1. Introduction
At the University of Vienna, we have decided almost
30 years ago, to split the main course (four semester) on theoretical physics
into two branches: one for those who want to become research physicists (either
in industry or basic research) the other one for those who want to become
physics teachers (in schools between the 5th and 12th grade, i.e. pupils aged
10 - 18 years). For the latter, we compressed the content of the "main
course" into one year, so that we had the other year left for all those
topics which are very important for teachers, but are not included in a
standard theoretical physics course (like particle physics, nuclear physics,
solid state physics, astrophysics, general relativity, cosmology and the like).
As a result, it soon became standard custom to call the main course the
"difficult" one and the teachers course the "easy" one.
Personally, I am teaching the two courses
alternately. Whenever I am starting to teach the course for physics teachers, I
tell my students that this is the more
difficult course for the following reasons: if you want to become a
research physicist, you have to be able to handle rather complicated
mathematics, you have to be able to write publications and get the necessary
information from the newest experiments; however, you do not have to understand what physics really is! On the other hand,
those who want to teach physics must necessarily have a deep insight into the
methodology of physics, otherwise their teaching will be in vain.
I also tell my students, that teaching physics to
young people has many different aspects, of which I would like to select three
of particular importance:
a) You have to prepare those who later on choose
to study physics at the University so that they get the basic knowledge. This
is important, but certainly not the most important goal of physics teaching.
b) You have to teach physics in such a way,
that those who later on do not choose
to study physics (who may never have close contact to any other physicist or
even scientist in general) so that they get enough insight into methodology and
structure of physics in order to be able to make correct decisions. Some of
them may choose to study law or political science and may sit in committees who
have to decide on energy policy or even whether accelerators should be built or
not. The fate of physics will also depend very critically on the ability of
those people to base their decisions on proper understanding.
c) However, I still think that this is not
the most important aspect of physics teaching! To me, the most important aspect
of teaching in any subject is to lay out all the various possibilities in front
of young people, so that they will be able to choose their profession according
to their best skills and interests not to say love. I think that this is
important for young people, for I believe that the decision to choose one's
profession and the decision to choose one's partner are the two most important
decisions in everybody's life (even in our time, when these decisions may
sooner or later be reconsidered). However, it is also of great importance for
physics! For I have no fear, that we will not get any students of physics in the future, but it may very well turn
out that we do not get those who have the necessary and sufficient creativity
in this particular area if they are not confronted with the challenges and
beauties of it.
In the mid-sixties (when I was a research associate at
the University of Virginia) the third point was not a very big problem; I
remember very vividly, that in those days in the so-called
"soap-opera" series on American television, the heroes who got all
the admiration of the most beautiful girls were always either doctors or
nuclear physicists. However, the attitude towards physics and science in
general has changed since these days and we are faced with a completely
different situation which we will carefully examine now.
2. The
Rise of Anti-Scientific Feelings in Western Societies
Until the late sixties, there was a general
consensus in western societies, that science will eventually solve all
essential problems. One was even contemplating to create ice-free harbours in
northern territories, to change the bed of large streams, to eliminate all but
one lock in the Panama canal or to cut through the Rocky Mountains; all this by
using nuclear explosions instead of dynamite. In our days, it seems hard to
even remember the mood of these years which now seems outrageously overenthusiastic.
I think we can place the turning point at
the "revolution" of 1968. Young students practically all over the
world expressed their general dislike of the way society was run and in western
countries this included a very critical attitude towards experts and
specialists. In Germany, students created the term "Fachidiot"
(idiot-specialist) and pointed out, that somebody who is specialist and expert
in one particular narrow field may as well be an idiot in general. Nobody would
have thought of such a combination of notions before 1968! The anti-nuclear
movement formed itself and this was a germ which developed into a quite
impressive plant with branches almost everywhere: a widespread anti-scientific
mood. (Nowadays, it is particularly active as the movement against
gen-technology.)
The general reaction of scientists is all
too often simply the opinion, that these are uneducated people and a better
education in science would prevent them from their opinions. Personally, I
think that this reaction stays too much on the surface of the phenomenon; I
would like to invite you to try to dig a little bit deeper. In order to do so,
we should look at the human being and its life in more general terms.
3. The Triangle of Essential Human Interests
If science allows us to formulate the laws
of nature, it is only one of many human interests. I would like to point out
two more, which then form a triangle of typical
interests and I do not claim that this should be in any way complete.
Besides the laws of nature, a human being is certainly also interested in the
meaning of life, in the questions as to origin and destination of the personal
selves, questions which are dealt with by philosophy (and maybe religion).
Furthermore, the beautiful aspects of the world and of life are the third human
interest which I would like to point out. We can arrange them in a triangle
SCIENCE ARTS
PHILOSOPHY
The laws of nature are universal, they are
objective and generally applicable. The human activity which leads to them is
the aim at determining these laws.
In arts, human beings try to create something unique. In philosophy,
human beings try to reflect the problematic,
the contradictory aspects of life such as the relation of time and eternity,
the meaning of a life which knows by itself that it has to end some time etc.
If you can accept my suggestion, it follows
that society is not genuinely anti-scientific, but it simply objects against an
uneven domination of science in the human realm. For the human being should
encompass all these three goals and the many others which lay between the
corners of the triangle. The aim of fulfilling one's life is balance between the
three corners and not the domination of one over the others. But if this is
acceptable, then the difference between scientists and a seemingly
anti-scientific society is not that of a fight in which one side is right and
the other one wrong, it is rather a misunderstanding in the communication of
the two sides. Let us try to illustrate that a little bit.
4. The HX-Confusion
The misunderstanding in the communication of
two sides is a rather common phenomenon and I have tried to clarify it by the
use of a simple model which I call the "H-model"1). According to my opinion, the
misunderstanding rests largely in an either-or attitude of both sides, each of
which claims that the own side is correct and the other one is wrong. In
reality, it is mostly so that there is right and wrong (or better: advantages and disadvantages) on both sides.
So I suggest, that each side looks at its own advantages and disadvantages. I
am fully aware of the fact, that in a
confrontation this needs some retreat from a heated dialogue in which such an
attitude is very difficult to attain.
We will probably easily reach agreement that
science with its laws of nature can claim general validity; it should be
equally easy to accept that it is restricted to matter in space and time. On
the other side, human society at large requests that human needs in general
should be of concern but it should also accept that human needs are subjective.
If we plot these aspects on the two bars of an H, we arrive at the following
model-picture:
General Validity Human
Needs
H
Restricted to Matter Subjective
The vertical bars of the H connect
advantages and limitations of each side and the horizontal bar should indicate
a balance or harmony between the two sides, each respecting the other one.
However, in practice the misunderstanding is born out in the fact that instead
of an H we have an X. Each side only considers its own virtues and the
limitations of the other one. We arrive at the following picture
General Validity Human
Needs
X
Restricted to Matter Subjective
I call this the HX-confusion and it is the
usual attitude in a conflict. If we want to come to an agreement between
science and society at large, we should try to avoid this confusion and go back
from the X to an H. In order to do so, scientists should recognize merits and
limits of their method, they should be aware of the fact (and publicly say so)
that science can not make any statements about the meaning of life. I am
personally very unhappy (not to say angry) when prominent scientists claim that
- as scientists from their own method - they can conclude that life is
meaningless (or else that it has a definite meaning). An example is the Nobel
laureate Steven Weinberg, who in his book about "the first three
minutes" of the universe claims at the end: "The more the universe
seems comprehensible, the more it also seems pointless"2).
Likewise, society at large has to recognize
that science is an essential part of its culture not only today but also in the
future. However, in order to communicate this, scientists should not simply lecture to society, in other words tell
society what is right and what is wrong, they should engage in a genuine
communication process, trying to understand the anxieties and needs of the
general public.
5. What is the Consequence for Physics Teaching?
Let us now turn to the main topic: physics
teaching.
In section 3, I have shown the
"triangle of essential human interests". Science is placed at one corner;
it is very important to recognize that this describes only the result of scientific work. The actual
process of achieving these results is certainly integrating all three aspects
of the triangle. The process of formulating a new law of nature is a creative
act, comparable to arts (this is why we speak of Newtons laws, Einsteins laws
etc.). This creative process usually starts from a philosophical problem; for
instance: "what is time?", what is space?" and the like. In
other words, in order to properly teach physics as a whole, we should remember
that science is a human enterprise, an activity of human beings which is
universal, objective and generally applicable only in its final results.
Consequently, teaching physics in the way that only the laws of nature are
explained and transported to the next generation is extremely reductionistic
and should not be called teaching physics at all! We should not be surprised
that young people do not like this subject if it is presented in this extremely
reductionistic way.
What should be the alternative? It is my
firm conviction that physics is really taught only if the method of science is
also included. In other words, in some way or other pupils have to participate
in finding the laws of nature, obviously under the guidance of an experienced
teacher. To illustrate what I mean, let me take an example: suppose the teacher
prepares an experiment. Before he or she actually performs it, he or she should
ask the pupils what result they expect. Hopefully, there will be disagreement.
The teacher should then encourage a discussion between various groups, supporting the weaker one, not necessarily the correct one! When he or she thinks
that the discussion does not produce anything new, the experiment should be performed
and provide the answer to the discussion. For it is the experiment not the
authority of the teacher which decides about right or wrong in physics!
Likewise, I am firmly convinced that it is
fruitless if not counterproductive to examine knowledge about physical laws and
physical results in tests. However, we do have to provide grades to our
students and pupils. For physics in the school, I usually propose to teachers
the following procedures: instead of a formal examination, let them prepare short
talks about a subject of their interest. If there are too many pupils in one
class, I would suggest a compromise, let them prepare these talks in small
groups. I am aware of the fact, that some totally disinterested untalented
pupils may use this opportunity to get a passing or even a good grade, however,
I think that this can be tolerated in view of the positive effects of this
method and in view of the fact that in large classes standard examinations may
become totally obsolete in the sense that they do not at all reflect the
genuine understanding of the subject. I would then grade the presentations of
single pupils or a group, I would reserve the best grade only for those who
choose a topic which has not been presented before by the teacher (and tell them
so).
Why can I be so extreme in this proposition?
There is one big misunderstanding about "knowing facts". It is very
often said that to our great regret, knowledge which is memorized for the sake
of an examination goes into the "short term memory". I would not be
so extreme if this were true! Unfortunately, besides the "long term
memory" and the "short term memory" there is a third kind of
memory which is sometimes called "waiter's memory", occasionally I
call it the "conductor's memory". It is a peculiar kind of memory
which memorizes facts only until a certain condition is fulfilled, after which
they are erased. The waiter in a restaurant uses this memory, he memorizes your
orders until you have paid. The conductor in a train remembers that he has already
seen your ticket until you leave your seat. (You can test this by simply moving
to another seat in the same or another car and you will notice that the
conductor asks you again for your ticket). I am reminded of this kind of memory
whenever I am on a journey: when I check into a hotel I remember the room
number without great difficulties. But after I have checked out, it is
completely gone and makes room in my memory for the next hotel-room number.
I claim, that most of the knowledge which is
just memorized for the sake of an examination is going into this kind of memory
and erased after the examination! Therefore, if you wish that your pupils
remember some of your teachings beyond the end of their school-time, you should
not ask them to memorize it for the
sake of examinations!
Since I am also a teacher at the university,
I have of course taken my own consequences. At the university level, one can do
it in a different way and the following procedure has turned out (after several
decades of experimenting) to be satisfactory. For students of the main course
in theoretical physics (beginning in the second year of university studies) I
tell them that for the examination they should try to understand what I have
taught in a four or five hour course of one semester. I add, that it is
completely impossible that they will understand everything! Those parts, where
they have difficulties either in understanding the general meaning and
connections or some mathematical steps (preferably they should have examples of
both kinds) they should note down and I will be prepared to answer those
questions instead of an examination. Needless to say, that the grade I give
them is not "objective" or quantifiable in any way. However, the idea
that the teacher or the examiner should in principle be replaceable by a
computer is appalling to me and I prefer to take personal responsibility in a
communication process like an examination.
This method is not possible for first year
students because they have to gradually grow into the university environment.
Since I am teaching a first year course in theoretical physics occasionally
(called "Principles of Modern Physics" in order to arouse their
interest in physics) I use the following procedure. I tell them that out of the
four, five or six chapters of my lecture they should pick the two which are of
greatest interest to them. They should then go to the líbrary and look for
additional literature and in the examination they should tell me what they have
learned in addition to what I have taught in the lecture. (In this way, I also
get them to use a research library very early in their studies). Over the three
decades in which I am a professor at the University of Vienna I have developed
the system and I am personally quite satisfied with it in spite of the fact
that it is neiter "objective" nor quantifiable. However in true life,
we very often meet the same situation. If a colleague of mine would ask me to
tell him about a certain applicant for a position which I will meet at the
occasion of a talk at another university, I would not go into the office of
this person and ask him or her questions of knowledge; rather, I would engage
him or her into a talk about their interests in physics and even if this
conversation is very short, I have to be prepared to give an evaluation to my
colleague. Why should I not use a similar system for my students?
6. Conclusion
Let me briefly conclude by reiterateing that
we should not pretend to be able to draw any conclusions about the meaning of
life or even the meaning of the world or "all that is" from physics.
On the other hand, we should insist both verbally and in our teaching
behaviour, that physics is and should remain a part of culture which is
different from other aspects of human life but an integrable part of it.
Literature
1) H. Pietschmann: Aufbruch in neue
Wirklichkeiten, Weitbrecht Verl., Stuttgart
(1997) p. 29 ff.
H. Pietschmann: Limits of Specialization and Integrated Approaches, in:
Potentiating Health and the Crisis of the Immune System (eds. Mizrahi et
al.)
Plenum Press, New York (1997) p. 39
2) S. Weinberg: The first three Minutes,
Andre Deutsch, London (1977) p. 154
This article is based on a talk given at a
conference on: Creativity in Physics Education, Sapron, August, 1997.