Teaching: Experience, interests and philosophy
Rafi Blumenfeld
My experience
As a Teaching Assistant at Tel
Aviv University I taught laboratory courses to undergraduates, problem-solving
in statistical mechanics and electrodynamics to physics graduates, and general
physics, classical mechanics, thermal physics and electromagnetic theory to
undergraduates. This involved frontal teaching, supervision during experiments,
clarification of lectures (sometimes to the point of completely re-lecturing
the course if the lecturer gave a particularly impenetrable course, which
happened all to often those days), demonstrations of problem solution, homework
assignment and marking and marking exams and course work. Most of the students
I dealt with came from physics and engineering but there was a fair amount of
classes that I gave to biology and medicine students. I believe I did not do
too badly as in the official surveys of teaching and instructing quality at Tel
Aviv University I was usually ranked by students among the top 10% in their
favourites.
At the Cavendish Laboratory I supervised for colleges second and third year
undergraduates in Classical Physics, Thermodynamics and Statistical Mechanics,
Dynamical Systems and Properties of Condensed Matter. At Princeton University I
gave lectures to students on Fractals and Percolation Theory in a course on
heterogeneous materials. This subject proved very attractive and popular among
the students.
At Los Alamos National Laboratory there are no undergraduate studies but graduates from other universities come to work at the lab for periods of a few months at a time. I have had one such a student, Yi Jiang from Notre Dame University, who worked with me on evolution of two dimensional interfaces and a coarse-graining procedure for heterogeneous media. She did very well and went on to become a postdoc and then staff member in Los Alamos.
My philosophy
In general I like teaching and I
get a great deal of satisfaction when I see on the face of a student that the
penny dropped. I believe that it is by far preferable to allow more time for
students to gain the fundamental understanding through practice rather than
drill them in solving problems by memorizing formulae. I believe that is true
not only at the university level, but even more so at the primary and secondary
education. I have found that teaching how to approach problems systematically,
remembering as few formulae as possible, is the most effective way to
produce thinking students. By relying less on memory and more on insight
students gain confidence and grow to experiment with the application of the
analysis and reasoning 'tools' that they acquire. While it is evident that for
graduates this approach is the only one possible (after all, the essence of
their career will be to solve problems that no one has solved before). I
believe that this approach, combined with emphasis on independent research
projects, is also essential at the undergraduate level. By and large,
independent projects get students excited about research and this is more than
half way toward the production of a good graduate. Another point to remember,
however, is that the university is not an extension of high school and students
need to be encouraged to independence in obtaining relevant material and to
hard work on problem solving, without which theoretical understanding is not of
much use. It seems to me that education to independence is not a high priority
in universities these days.
Most important is that students get a broad and an in-depth knowledge of the
state of the art in science. In today's world there is a need to produce
scientists at all levels who know how to apply their expertise flexibly and
practically. Nevertheless, a good education system has to identify students
showing the inclination and appetite for research and provide those with the
freedom to conduct their own line of research, even at the expense of giving up
some conventional studies. As the history of science shows, it is impossible to
predict where the next breakthrough will come from. It is certain though that
such breakthroughs are more often than not the result of original thinking and
alert minds, not just of familiarity with the body of existing knowledge. There
is a delicate balance that has to be struck between the teaching of current
knowledge and the nurturing of creativity. Giving freedom to follow one's
interests should encourage original thinking and is bound to prove essential in
today's society.
Personally I regard teaching and supervision as paying my debt to those who educated me to become a creative physicist. I will elaborate on my personal views regarding student-advisor relations below. I would leave my door open to students to discuss anything from clarifications of the lectures (mine and others'!) to creative ideas that they might have. More importantly, I would also encourage them to think about the ramifications of the subjects discussed in class in any field. To me, one of the signatures of a potentially good student is the ability to ask questions whose answers may not be clear even to the teacher. And there are plenty of those around. I believe that acknowledging the large gaps in current scientific knowledge tends to attract students. One of the worst things that a teacher can do is pretend that s/he knows something s/he does not. Therefore I think that 'embarrassing' questions should be not only acknowledged but also rewarded. It definitely should not be quenched by refering to existing formulae, which are usually limited by their simplifying implicit assumptions.
Student - advisor relations:
My principal advisor throughout my graduate studies at Tel Aviv University was professor Amnon Aharony, whose approach to advisorship was probably not too common. His main goal was that a student finishing a Ph.D. with him would be in the best possible position to when getting out into the scientific arena. This means that he not only guided me in learning the necessary technical skills but also made an effort to expose me to all the top-ranking scientists in my, and related, fields so that I become connected. When a visitor would come to the department he would collect all his students in his not-too-large office and the visitor would present his work and discuss it with all of us. Amnon would usually lead the discussion but would later retreat and let the students take over. He sent me to as many conferences as possible, selecting (under budget constraints) the conferences that maximised exposure and interaction. These were usually the most prestigious ones. I remember one instance when, while I was in his office, he got a call from Mandelbrot who apparently needed someone to work with for a few months. He turned to me and asked off-handedly "would you like to go to Benoit for a couple of months?" "Yes", I said, "When?". "Next week" replied he. I did set off only slightly more than a week later for about four months to what proved to be a very educational experience. Amnon also put a lot of effort in teaching me to write clear manuscripts. A draft manuscript would come back to me completely covered with red ink at least 15-20 times before he was satisfied. Interestingly, he did not extend a lot of help, at least to me, beyond the Ph.D., perhaps because he felt that I need to fight for my own place under the sun.
When Amnon went abroad for a sabbatical I approached Professor David Bergman who
agreed to be my second advisor. (Interestingly, he took a sabbatical the
following semester. The administration, astutely making the connection, warned
me in advance that I could not take a third advisor even if I tried lest he
takes off too!). Having been exposed to two different approaches to doing
science was a big advantage in my education. David's style was completely
different from Amnon's: He was very methodic, doing every calculation himself
to the last iota and rounding up every possible detail before publishing
anything. In contrast, Amnon would cut quickly straight to the heart of a
problem and then organise the plan of attack to resolve it and publish the
result. David would play with one problem for a long time until he was sure
that we haven't missed any detail. He also made a point of educating me in the
etiquette of science. He used to repeat to me that one GOOD paper a year is
worth more than five half-baked ones and that therefore I should put a lot of
time and effort in making the paper good even if I believe I solved the problem
and I wanted to be off to the next one. On top of that he was one of the most
critical persons I have ever met. The collaboration with both of them produced
a good list of papers, some of which were real gems from my perspective.
All this, however, is on the surface or just below it. A lower-lying theme, of
which I was aware already as a first-year graduate student, was the emotional
undercurrent. In retrospect, I see advisorship as not too different from
parenthood (In fact, I could easily take Bill Cosby's book on the subject and
interpret it in terms of this situation). The advisor receives a raw student
and moulds him into a scientist in whatever way that he perceives a scientist
should be. Isn't this what parents do with children? The student first looks up
to his advisor with admiring eyes, thirstily drinking everything that is poured
down on him, much like toddlers do. Then the student tries hard to prove
himself to the advisor. Gradually, however, as the student becomes more
involved in his field, he starts to notice that there are some things that he
knows better than the advisor. This is where the 'teen-age'-like period sets in
and the budding feeling that he can eventually surpass the advisor. In due course
the student leaves the nest to make do on his own, and, looking back, starts to
appreciate the values and education that he received. All this process is not
dissociated from emotions that resemble those between children and parents:
Devotion, love, disappointment and feeling of being abandonned at times.
Talking to quite a few colleagues on this subject, I found that I am not alone
in this view and quite a few felt a child-parent sort of relationship with
their advisors.
I absorbed much from my advisors and the standards that they set are with me to stay. Whatever I have been given in this respect I regard as a debt that I need to repay to other students, inasmuch as my debt to my parents I repay to my children. Hopefully, I will be able to follow and continue the line of good mentorship that my advisors exemplified.
Cavendish Laboratory
Madingley Road, Cambridge CB3 0HE, UK
Tel: +44 (1223) 337-001, Fax: +44 (1223) 337-000
Email: rbb11@phy.cam.ac.uk