Water colours
On February 28 we remember a great scientist — Sir C.V. Raman. His
discovery placed India on the world Science map. He was the first person
from Asia to be awarded a Nobel prize in any field of science.
A glass of water has no colour. But a deep sea with the same water is a brilliant blue. Why is this so?
This was the question that C.V. Raman asked himself in 1921 on seeing
the colour of the Mediterranean sea from a ship. He immediately began to
conduct experiments on board the ship using some simple instruments he
had with him. At that time, scientists believed the sea was blue because
it reflected the colour of the sky, but Raman found that it was the
water itself that caused blue light to scatter more than other colours
in light.
At that time Raman was a professor at the University of Calcutta. He
returned from his visit of England and Europe and started experiments to
study how light behaved when it passed through various substances. On
February 28, 1928, one of the experiments gave a clear result. Light of
only one colour was passed through a liquid, but the light that emerged
had small traces of another colour. This meant that the molecules in the
liquid were changing the colour of some of the light passing through
it. The discovery created a sensation around the world and was named the
Raman Effect. In 1930, C.V. Raman became the first person from Asia to
be awarded a Nobel prize in any field of science. The date of the
discovery, February 28, is now celebrated as National Science Day in
India.
The Raman effect has been very useful in many areas of science. It was
found that when light was passed through a substance, a series of
colours were seen that could be thought of as a fingerprint of the
substance. This idea has been used in chemistry, medicine, biology and
many other areas of science to find out what a substance is made of.
Recently, people have used the idea to make a device called a Raman
Scanner. It can be pointed at a substance to tell what it is. Police
have begun to use this scanner to find out if people are carrying any
banned substances.
Not all of us will be as brilliant as C.V. Raman. But on the occasion of
National Science Day we must remember that we can all be just as
curious about the world as he was.
Simply brilliant
Raman was a man of extraordinary ability. He passed his Std. X when he
was just 11 years old. At 15 he had a degree, with gold medals in
Physics and English. By the time he was 19 he had an MA. Professors at
college used to allow him to skip science classes because they knew he
didn't need them. In addition to being brilliant, Raman was also
intensely curious about the world around him. We saw how his curiosity
about the colour of the sea led to the discovery of the Raman Effect.
Similarly, his curiosity led to a wide range of scientific work. On his
1921 trip to England he was taken to see St. Paul's Cathedral. Raman
became so excited by the whispering gallery there that he performed some
experiments and wrote scientific papers about it. As a child, Raman had
seen his father play the violin. Much of his life's research work was
about the science behind music. He also investigated the effect of sound
on light and the structure of crystals. His collection of crystals is
preserved at the Raman Research Institute in Bangalore.
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