Tuesday, August 25, 2009

On teaching Physics


On Teaching Physics : A Letter from a Grown-Up Student to his
Veteran Teacher
Tirtha Pratim Das
To
Fr. A. Wavrail,
St. Xavier’s College, Kolkata
Dear Father,
It is a real pleasure to share my thoughts and beliefs with you since you have seen me from
my childhood and have witnessed my every evolution, both physical and intellectual, very
closely. I shared with you how did I enter the world of physics out of bewilderment and
ecstasy, and how am I evolving continuously with my ideas and thoughts. Let me , first of
all, send you and all the respected Fathers and Teachers my warm regards on the auspicious
occasion of Teachers’ Day, before, on this auspicious occasion I once again share with you
some thoughts regarding the knowledge development of the students and the role of modern
teachers in the same.
Any branch of knowledge, may it be science or humanities, demands something common in
order to bloom into totality, regardless of the contents and the view it takes towards reality.
That common thing is a set of trio, which Buddhists call ‘Buddha, Sangha and Dhamma’. If
you happen to visit any Buddhist monastery you can listen to their chants “ Buddham
Saranam Gachhami (Taking recourse to Buddha), Sangham Saranam Gachhami (Taking
recourse to Sangha) , Dhammam Saranam Gachhami (Taking recourse to Dhamma)” .
These prayers are of great relevance to any branch of knowledge and realization. I will
elaborate the same in connection with physics.
Towards proper realisation of physics, we require Buddhas, which mean ‘enlightened
teachers of physics’. An enlightened teacher of physics should be like a magician; wherever
you catch him in whatever position, may it be on the road, may it be sitting quietly on a
park-bench, or in a restaurant, and ask him about a concept, he would be able to answer it
lucidly. If a layman asks him about the mystery of this Universe, what makes the planets
revolve round the Sun, he would answer with his usual ease and his exquisite lucidity and
smile. That makes a magician in physics. Such an enlightened person would know lots of
mathematics , the ins and outs of the toughest theory of differential geometry or tensor
calculus, but, that knowledge would gift him the realization that how dispensable they are.
Really an enlightened teacher can avoid gamut of mathematics and explain the toughest
theory of physics to a layman like a magician; each and every word of him would carry
immense energetic dimensions which is equivalent to thousand lines of mathematical
equations; his popular lecture, which contains no mathematics, can make people visualize
what’s going on in the arena of the tiniest of the fundamental particles as well in the
gigantic vastness of the remotest galaxies.
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These kind of teachers have a great impact on their students. Not only at the time when they
deliver lectures at classes, but also when a student studies on his own. I myself used to
imagine , when I used to study any topic of physics on my own, that my subject teacher is
present in front of me and explaining all these to me, even if I was alone in the room. I
imagined the topics to be coming out from his mouth. It used to give me convenience. This
psychology of a student associates the dependability of his/her teacher with his/her own
understanding, which, in turn, blooms into realization.
There was a time when I was a teacher, teaching Physics and Mathematics, along with
electronics engineering. I told my students on the last day with them (before I left to join
the Indian Space Programme) in a lecture session that all my efforts in teaching, at their
level best , could impart 50 % of the understanding to them. They were wondering why was
I telling them like that, only 50 % ? Then I explained, there is a second phase , which will
fetch you 25 % more understanding. What is that ? That is sharing of understanding and
discussion among the fellow-mates . When you discuss the ideas in a group that you have
learnt, a positive feedback prevails and that eventually strengthens the understanding,
enhances the power of expression, and when one expresses an idea, he himself listens to his
own words which , in turn, offer more meaning to the subject. The last 25 % will come as a
blessing; one day all of a sudden you discover yourself enlightened, nothing is hidden to
your intellect, to be more precise, the limited domain of ‘intellect’ also vanishes, you bloom
into totality which is beyond words, mind or intellect.
This is the concept of having Sangha, i.e. group. It is very much necessary to have a
Sangha in order to share the same ideas , breathe in the same air of environment. This
sometimes gives rise to even a new school of thought. This was exactly what we used to do
during our M.Tech. course at Calcutta University. During M.Tech. we had to study
different subjects at immense depth, and the teachers had the time pressure to complete
their respective syllabi. You can imagine what happens when one has to devour food
without crunching , and the same thing would have happened to us, the entire batch, unless
one of my friends, Mr. Tilak Nandi came out with a bright idea.
We had a famous canteen at the Rajabazar campus of the Calcutta University, where we
used to visit regularly to get refreshed. At that time the M.Tech. course was going on at full
pace. Six of us found ourselves, one afternoon, at the canteen table, with 7 UP drinks. It
was Tilak who gave this idea.
“What about forming a group of teachers among ourselves and re-teach our fellow-mates
all the subjects in a capsule form that we have come across in M.Tech. ?”
“Sounds good ! But there are so many subjects. How many volunteers would you expect to
get ?”
“That will not be a problem. We can chalk out a plan first. I am sure the rest of the class
also will welcome our idea because they also find difficulty in absorbing what are being
taught in class.”
“Well, get a piece of paper…… Lets chalk out.”
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That was the beginning. We six of us split up the entire M.Tech. course in different relevant
parts, and we assigned six of us to take up some subjects to teach. Some took Lightwave
technology and photonics, some took Digital communication, …… I myself took Advanced
mathematics and Quantum and Solid State devices.
We announced the idea in our class. The response was joyous. Everybody welcomed this
idea because they themselves wanted to clarify their doubts, and being peers, we could
understand our own difficulties in understanding, rather than an experienced professor. We
started the course during vacation.
During long vacations, the students used to get a month of holidays, while the teachers had
to come to the institute. They were astonished to see that at the top floor of the Institute of
Radiophysics and Electronics building, where the M.Tech. students used to attend their
classes, a group of students with full strength, attending some lectures on a regular basis.
They used to peep and got amazed to see either me or somebody else offering a class on an
advanced topic which they have taught us, and the attendance in the class was full.
This immensely helped us in understanding our own subjects. Another idea came out from
me. I asked to my friends…
“Why stopping here ? Why don’t we prepare very good quality notes on each and every
topic and distribute to all of us ?”
“You mean to all of us ?”
“Yes. To all of us. The benefit should go to al of us.”
“I understand your point. But, who will make the notes of so many subjects ?”
“We will not invite all to prepare the notes. Only selected persons who show interest in
respective fields would take the responsibility to prepare the notes on respective topics. And
the work should move in a project mode….. there should be a part chart, the work should
be time-bound.”
It happened . I was told to take the responsibility to communicate between the students who
were making the notes, ask them regularly about their progress and estimate the time
required to complete this project. I myself made notes on Advanced Mathematics, Quantum
and subjects like that.
Within a month or less, we assembled our notes.
It was a thick collection of all the knowledge we were supposed to acquire during M.Tech..
It was written by a group of enthusiastic students who learnt their subjects with respect,
who used to feel excited about their subjects. Their enthusiasm and excitement got reflected
in the quality notes. Some of them also solved previous years’ question papers. This gave
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rise to an excellent compilation. That was, however, hand written. Now I think, had it been
computer-typed, we could have compiled it in a very systematic manner and could have
made it available to the next generation students.
We set, in our Institution, an example of Sangha. We learnt so many things out of this
project. The spirit of team work, project management, teaching, etc.. Later , when I became
a teacher few months right after that, I used to tell these stories to my students. They used to
find it bewildering, because, unfortunately the feeling of Sangha was not among them
except at the time of writing the examination, which , again, I used to prevent. I could not
blame them, because, they have not witnessed any such example of Sangha in front of them
which they could have taken as their role model.
There is another advantageous outcome of having Sangha. Being in a group always
cultivates fellow-feeling, which is based on some common interests and thoughts, which
bind everybody together. Each individual in the group starts strongly believing about the
ideologies prevailing in the group. Like, a group of physicists forming a school of thought
will have a strong belief on their ideas. They will be proud of their identities of belonging to
that group , which, in turn, will give them strong confidence on their own knowledge and
abilities. This is Dhamma.
These three points viz. Buddha, Sangha and Dhamma define a triangle which hold
collectively the base of becoming a master in any branch of knowledge. Here , at this point,
whenever I look at the present scenario of studying science and engineering, I find, to my
great agony, that, everything is in dearth.
You can very clearly identify a vicious cycle here which causes this sustained problem. A
great fraction of the teachers are not themselves motivated about their subjects, they
themselves do not feel excited about what they teach. As a result, the students also never
feel the life in the subject and it seems to be a dry stuff. They can not correlate whatever
they learn with their everyday lives, the teachers also don’t think of the real life examples
of the basic physics they teach. The result is catastrophic, because the students start
thinking that whatever they are being taught is something alien, which is a stand-alone
knowledge, which is no way connected to the real life, and hence got only exam-related
significance.
I describe this situation catastrophic in true sense of the term. As they don’t get the flavour
of a subject, that carries no meaning to them, which, in turn, results in to the inability to
correlate different subjects. One can not expect of discovering the undercurrent of unity of
different branches of knowledge unless he can appreciate the energetic current in a given
subject. The outcome is to become like a mule, who can carry knowledge as a luggage,
without really having even mere access to it. They receive degrees, diplomas and
certificates, it becomes a very funny comedy of their lives, a tragedy too, at the same time.
As the knowledge becomes void, there is no point in telling about ‘realization’, which is the
next step to knowledge. So, we can never expect such students discussing the topics among
themselves, except about how to downsize the syllabi during preparation for the
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examination, and how to further divide that downsized syllabi among themselves in order to
create a sangha (!!) at the examination hall.
One day one of my students asked me :
“Sir, in real life we all have to work in groups. Nobody will be lone travelers, as you
yourself tell. Then why do you refrain ourselves in ‘consulting’ each other during
examination?”
(This poor fellows did not have the slightest idea that it was called cheating.)
I replied , “Well. Suppose, you work in an organisation, in a big project. You are attending
a meeting. Or, imagine, your team is handling the most difficult part of the project. What
would you do ?”
“Why, we will discuss among ourselves.”
“Right you are. But suppose, in your team nobody has learnt anything, everybody relied on
‘consulting’ during exam when they were students. So individually all of them are big zeros.
Now, what sort of consultation would you expect to handle the project ? Moreover, in a
meeting, when you are asked something by the chairman, would you start ‘consulting’ with
somebody else , or try to answer on your own ?”
I continued: “Team spirit gets its meaning only after each individual of the team is capable
of standing on his own feet, as a stand-alone entity. This calls for becoming self sufficient.
More knowledge, more power. Once you are confident with your own subject, you can
distinguish between a show-master who bluffs people and the person who really knows and
hence can manage a group, become a leader. Then comes your team spirit.”
Another thing which renders knowledge suffering from leukemia is its
compartmentalization. The student of physics does not show interest in biology or history
or sociology. He doesn’t pay interest any more, as he ‘grows’ further, to the other areas of
physics barring one or two (that is called ‘research’), get still ‘focused’ by isolating himself
from the rest of the world. I am not against focusing, neither I disagree in going to enough
depth of a subject, but that should be done only with some minimum foothold on the other
subjects. Otherwise, there is no completeness. I really pity those ‘physicists’ who can not
see the thermodynamics in ‘history’, quantum statistics in ‘sociology’, statistical mechanics
in ‘economics’, particle physics in ‘neuroscience’, so on and so forth. What is the use of
that knowledge which doesn’t promote oneself to ‘realization’ ?
So, there is neither Buddha, nor Sangha. In absence of these two, there is no faith in one’s
own subject (I have heard people saying “That what ‘physics’ says, but in real life
…………”), and hence no Dhamma. All the three pillars are absent, where does knowledge
stand ? This is the root of the problem in almost every branch of knowledge today.
For these, I never blame the students. It is us who have failed in inducting them to the right
spirit.
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Whenever these poor fellows themselves get selected for teaching by the virtue of their
certificates, you can easily assess what will they teach to their students and what, in turn,
will they pick up. Likewise, generations after generations, we are diverging to more and
more chaos, which, ironically, is a law of physics by itself (law of entropy, the second law
of thermodynamics). If you want to bit the chaos, get ordered, you have to supply energy
externally to the system in form of your right intention and enthusiasm.
I tried to tackle the problem in some different way when I was a teacher. I had to offer both
theoretical and practical courses on Electronics at undergraduate level. The faculties had to
conduct class tests in regular intervals; and the marks were added to their public
examination marks. In order to prevent them from cheating , I announced to offer an open
book exam. I knew people feel irresistible affinity for things which they are prohibited to
do; if I officialize copying from books, the charm of ‘consulting’ will be killed. And I
wanted that.
I announced “You may keep any book open, even I won’t mind if you keep my lecture notes
also open while you write this class test.”
They could not believe first. Later they realized I was serious about that. Then I added
“However, my questions will not be straight forward like ‘state so-and-so law’. I will ask
conceptual questions which will call for a deeper understanding of the topics I have taught.
So, even you keep all of the materials open while you write, it will not help if you have not
understood.”
They agreed. They understood that they were going to experience something very
interesting. In order to prevent them from helping their friends at the time of exam., I made
a further announcement. “And I am not going to call it an exam., rather it is a competition.
The first three scorers will be awarded.”
It worked. Nobody showed their answer paper to their friends, nobody discussed in the hall,
although they were feeling a bit uneasy to consult books openly (they all were habituated to
do the same secretly). After my announcement, they started preparing for my exam in a
different way, and to my utter surprise, all performed well in that exam., although the
questions were very conceptual.
Something more interesting happened during practical exam.. It was very boring of the
examiners to individually take the viva-voce exam of about 90 students in a class (5 or 6
such classes) . It was monotonous and the students were also managing to escape taking the
advantage of the intellectual tiredness of the examiners. I adapted a different technique.
Instead of taking the interview of a single student at a time, which was taking lot of time, I
gathered eight of them together for the test. All were surprised how could I take the test of
the eight at a single stroke.
I grouped them into two. Four students facing the other four, all sitting. “Now, group1, you
are a group of engineers who use analogue filters in your work. These people (group 2)
have come to sell digital filters to you. Group 2, you use your salesmanship and technical
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expertise to convince them that the digital filters are superior to the analogue ones. Group
1, you are going to purchase digital ones from them; before that ask the ins-and-outs of
their products. No, start your conversation !”
They started. It was unbelievable, all were boiling with enthusiasm. From their discussion,
so many points came out, which , otherwise, in conventional ways of examining, would
have taken the form of some text-bookish questions like “What are the advantages of
Digital Filter ? What are the differences between ………. Blah blah blah” Students
memorize most of all these answers without understanding, and even if the teachers
understand that the student is memorizing only and have not understood, he is bound to
give marks because, after all he could answer the question. In this conversation, which was
an extempore dramatic version of group discussion, the spontaneity of each individual
indicated their respective understandings. I arranged similar things for other groups of
eight also: “ Okay, you eight are the electronics lecturers of this college. You are the head
of the Department. Discuss among yourselves how to set up a laboratory in the college for
Basic Electronic Circuits.” Like this, so many.
The students went on discussing, the examiners did not have to talk much, eight students
were examined at a stretch, proper evaluation was also done. Above all, when all the
candidates were examined, the Class Representative (CR) came to me
“Sir, it was nice of you to conduct the exam in this innovative way. It was never boring. We,
when sitting as audience watching the other students playing different roles, enjoyed as if
we were watching a drama. It also helped us a lot to get out of the exam tension. When we
ourselves had our respective turns, we felt like acting in a movie. Smart of you, Sir!”
Good recognition. Not only recognition, the main thing is that this innovation,
unconventional way of thinking, touched the hearts of the students which they will never
forget. If some of them become teachers, they will also dare to be innovative. This will pay
forward to the next generation of students.
I still cherish those days. So thought of sharing with you. Everything will change, the mode
of teaching, contents, …. But the basic thing that will never change its fundamental form is
the relation between the teacher and the taught. It will continue to ooze its fragrance.
Take care of your health. My warm regards to all the respected Fathers and teachers.
Warmth for the juniors.
Yours Lawrencianly and Xaverianly,
Tirtha Pratim Das

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