Those unforgettable and informative demonstrations

A day that’s filled with sad memories looms over me recalling the day she left us so very suddenly. As time goes by some say the heartaches subside, but the feelings in my heart today are just the same even after the lapse of two years.

I often think of the good old days when we were kids, the seven of us together, laughing, joking, teasing and even quarrelling with each other. Those were happy years and then when we grew up still the bonds of affection never left us, understanding each other, helping each other and extending to each other support and co-operation in happiness as well as in times of calamity.

We have lost her now – things have changed – the light in our family is gone. Society especially the not so rich may be missing her the most remembering the help she extended to them with love and affection, easing their burdens whenever possible. She was so loving, caring and helpful. I miss you terribly darling sister. As each day passes the emptiness grows, it is not difficult to keep back tears but my aching heart will always remain with me.

This is samsara – the never ending stream of life. You meet – you love and then depart. As the years go by slowly, in our hearts she will always stay, loved, missed and remembered every day.

Karunakka

Emeritus Professor of Physics and a former Head of the Department of Physics at the University of Colombo Professor Lakshaman Kannangara, passed away on September 26.

Like his many students, I was immensely privileged to have known him, first as a teacher and later as a colleague, and to benefit from his vast experience as a true academic and scientist.

Professor Kannangara was born on March 29, 1925. He graduated from Royal College, Colombo, in 1943 and entered the University of Ceylon, where he obtained a BSc Honours Degree in Physics in 1948. Soon after, he joined the University as an Assistant Lecturer in Physics and proceeded to theUniversity of Manchester, UK, where, within the research group of Professor George Rochester, he studied the properties of cosmic rays in the atmosphere. During this time, Rochester and his students discovered the so-called strange particles – which many regard as one of the greatest discoveries in physics not to be rewarded with a Nobel Prize. For his work in Manchester, Professor Kannangara was awarded the degree of Doctor of Philosophy in 1953.

Returning to his motherland, he then served as a Lecturer in Physics at the University of Ceylon until his promotion to the grade of Associate Professor of Physics in 1970. He was further promoted to Full Professor and Chair of the Department of Physics in the University of Colombo in 1979 and held this position until his official retirement from active duty in 1990.

During this period, Professor Kannangara was just one of a handful of scientists who successfully continued to conduct active research in Sri Lanka. His work on geomagnetic micropulsations resulted in a series of papers in the Journal of Geophysical Research, the leading scientific journal in geophysics. These findings were significant as they were based on observations made in the proximity of the geomagnetic equator, which runs right through Sri Lanka. His work served to demonstrate that quality research could be carried out in Sri Lanka and published in highly reputed international journals.

His achievements received international recognition when, in 1967, he was elected a Member of the American Geophysical Union and in 1971 to Fellowship of the Institute of Physics, London.

In the early seventies, together with his close friend and colleague Professor Osmund Jayaratne, he initiated a research programme in atmospheric electricity and lightning physics at the University of Colombo. This programme produced many outstanding researchers and gave rise to many scientific publications. He was instrumental in setting up a collaborative agreement with the International Seminars, University of Uppsala, Sweden, which continued to serve the Universities of Colombo and Uppsala with great advantage for many years.

In view of his academic achievements, service to the University system and in recognition of his invaluable contribution to national development, Professor Kannangara was conferred the Degree of Doctor of Science Honoris Causa in 1990.

Throughout his illustrious career, his many students will always remember him as a dedicated teacher with a sound passion for Physics. Prof Kannangara was that rare breed of teacher who always placed emphasis on the basic principles of science. He would take great pains to explain the fundamental principles in detail before describing how they may be applied in the real world. He often carried this out by means of very informative lecture demonstrations, whether it was a beach ball suspended in the airstream from a vacuum cleaner to demonstrate Bernouille’s Principle of Fluid Motion or a student cajoled into sitting on a rotating stool, carrying two dumbbells, to demonstrate the Law of Conservation of Angular Momentum. Both these demonstrations were received with tremendous enthusiasm and served to instil a love of science in many of his students.

I well remember another time when he was teaching a large first year class in the Old Physics Lecture Theatre; he brought with him a bow and arrow to the class. He then proceeded to explain how potential energy is converted to kinetic energy by literally shooting the arrow through the lecture room door. Unfortunately, our trusted Laboratory Technician, Mr Silva, happened to be passing right at that moment and received the shock of his life when an arrow whizzed past an inch of his bald head and landed in the quadrangle outside!

In later years, he persuaded a group of us students to build a model to demonstrate the occurrence of lightning. The lightning bolt was simulated by applying a high voltage across two electrodes using an induction coil. At the same time, a young first-year student was asked to stand at the back and rattle a sheet of aluminium to create the sound of rolling thunder. An elaborate model was constructed, with matchbox houses and plasticine cars on a green cardboard landscape representing the ground. A short distance above the ground was suspended a canopy of cotton wool, representing a thundercloud. One of the electrodes was hidden under the cardboard and the other was embedded within the cotton wool cloud. After a long and interesting description of the phenomenon of lightning Professor Kannangara announced to the large gathering of schoolchildren and teachers that we will now produce a lightning bolt. The order was given to switch the induction coil on. Lo and behold, there was a bright spark and a mighty roll of thunder! But what no one had anticipated was that cotton wool and cardboard were inflammable materials. In an instant, there was not only lightning and thunder but a fire to go with it. The induction coil was quickly switched off and disconnected. Mr Silva was hastily summoned with a bucket of water to douse the flames. I still recall a visibly flustered professor telling the half-drenched first-year student with the aluminium sheet that he could stop rattling it now!

Professor Kannangara is fondly remembered with gratitude by many of his students and colleagues not only in Sri Lanka but now scattered through many parts of the world. Dr. Rohan Jayaratne