|
|
DI:Personality
Dr.C.V.RAMAN
Not a Minute to Waste
Absorbed in experiments, it was not unusual for him to forget food and sleep.
Sometimes working late at night, he would sleep in the laboratory on one of the
tables.
In the mornings too, most of his time was spent in the laboratory. He worked in
informal clothes. At 9.30 a.m. he would rush home. After a shave and a bath he would
dress up and send for a taxi. He would finish his breakfast in two or three minutes
and get into the taxi. Racing over a distance of four miles, he would reach the
class on time. He never wasted time.
In England
The Congress of the Universities of the British Empire met in 1921 in London. Raman
went to England as the represen- tative of Calcutta University. This was his first
visit abroad.
Raman lectured in the ‘Physical Society’ of London. People came in large numbers
to listen to him. He was introduced to J.J. Thomson and Ernest Rutherford, the
famous English Physicists. Raman visited St. Paul’s Church in London. A whisper at
one point of the church tower is heard clearly at another point. This effect,
produced by the reflection of sound, aroused his curiosity.
The Blue of the Sea
Raman’s journey to England and back was by sea. In his leisure hours, he used to
sit on the upper deck of the ship and enjoy the beauty of the vast sea. The deep
blue color of the Mediterranean Sea interested the scientist in him. Was the blue
due to the reflection of the blue sky? If so, how could it appear in the absence of
light? Even when big waves rolled over the surface, the blue remained. As he
thought over the problem, it flashed to him that the blue color might be caused by
the scatter- ing of the sun’s light by water molecules. He turned over this idea in
his mind again and gains. Immediately after his return to Calcutta, he plunged into
experiments. Within a month, he prepared a research paper and sent it to the Royal
Society of London. Next year he published a lengthy article on the molecular
scattering of light.
Raman never held the wrong belief that research could be carried out only with
foreign-made or very complicated equipment. No doubt, he imported some equipment.
No doubt, he imported some equipment. But he prepared much of the equipment he used
with the help of his students.
New Contacts
Scientists of many countries appreciated the research papers of Raman and his
colleagues. The Royal Society, the oldest and the most important science society
of England, honored Raman in 1924 by electing his as its ‘Fellow’ (that is, a
member).
The annual session of ‘The British Association for the Cultivation of Science’ was
held in the same year in Toronto (Canada). Raman inaugurated the seminar on the
scattering of light. R.A. Millikan, the famous American Physicist, who also
attended, was full of admiration for Raman. They became fast friends too.
At the Mount Wilson Observatory in California (U.S.A), a telescope of 100-inch width
was in use. Those were the times when discoveries in the field of astronomy (study
of stars and planets and their movements) filled people with wonder. Raman was
always eager to learn new things. He spent a couple of days onMount Wilson. During
the nights he viewed the Nebula (bright or dark patch in the sky caused by distant
stars or a cloud of gas or dust.) Through the telescope and was thrilled.
He went to Russia in 1925 to participate in the twohundredth anniversary of the
‘Russian Academy of Sciences’.
The Guide
Many scholars were working in the Calcutta laboratories to unlock the secrets of
sound and light. To all of them Professor Raman was the 'Guru' and the leader. He
had observed the blue color of the deep glaciers (mass of ice or snow) in the Alps
mountain ranges. Taking the clue from this, some of the research workers studied
some scattering of light in ice and quartz crystals. They also studied the
scattering of light in liquids such as pure water and alcohol, as well as in vapors
and gases.
With a complete mental picture of the phenomenon, Raman would proceed to experiment
systematically. After that he would write the research paper based on the results of
the experiments and arrange for its early publication. Sometimes it would be late in
the day by the time the final copy was prepared. Then he would rush to the General
Post Office in a taxi to catch the last mail. Then he would enjoy a feast of
Rasagulla with his students.
He started 'The Indian Journal of Physics' in 1926 to make the prompt publication
of research papers possible.
Raman wanted the young men working with him to take up indepenent positions and to
serve the nation. He felt that his laboratory was a centre of training for young
talent, but not a permanent storehouse.
Raman's research on sound became famous allover the world. 'Handbuck der Physic', a
German Encyclopaedia of Physics, was published in 1927. Raman was the only foreign
scientist invited to contribute an article to it.
Raman Effect
Sometimes a rainbow appears and delights our eyes. We see in it shades of red,
orange, yellow, green, blue, indigo and violet. The white ray of the sun includes
all these colors. When a beam of sunlight is passed through a glass prism a patch
of these *color- bands are seen. This is called the spectrum. The Spectro- meter
is an apparatus used to study the spectrum. Spectral lines in it are characteristic
of the light passing through the prism. A beam of light that causes a single
spectral line is said to be monochromatic.
When a beam of monochromatic light passes through a transparent substance (a
substance which allows light to pass through it), the beam is scattered. Raman
spent a long time in the study of the scattered light.. On February 28, 1928, he
observed two low intensity spectral line corresponding to the incident mono-
chromatic light. Years of his labor had borne fruit. It was clear that though the
incident light was monochromatic, the scattered light due to it, was not
monochromatic.Thus Raman's experiments discovered a phenomenon which was lying
hidden in nature.
The 16th of March 1928 is a memorable day in the history )f science. On that day a
meeting was held under the joint auspices of the South Indian Science Association
and the Science Club of Central College, Bangalore; Raman was the Chief Guest. He
announced the new phenomenon discovered by him to the world. He also acknowledged
with affection the assistance given by K.S. Krishnan and Venkateshwaran, who were
his students.
The phenomenon attracted the attention of research workers all over the world. It
became famous as the 'Raman Effect'. The spectral lines in the scattered light were
known as 'Raman Lines'.
Is light wave-like or particle-like? This question has been discussed from time to
time by scientists. The Raman Effect confirmed that light was made up of particles
known as 'photons'. It helped in the study of the molecular and crystal structures
of different substances.
World-Wide Interest in Raman Effect
Investigations making use of the Raman Effect began in many countries. During the
first twelve years after its discovery, about 1800 research papers were published
on various aspects of it and about 2500 chemical compounds were studied.Raman
Effect was highly praised as one of the greatest discoveries of the third decade
of this century.
After the 'lasers' (devices that produce intense beams of light, their name coming
from the initial letters of 'Light Amplification by Stimulated Emission of
Radiation) came into use in the 1960's, it became easier to get monochromatic light
of very high intensity for experiments. This brought back scientific interest in
Raman Effect, and the interest remains alive to this day.
Next
|
|
