By T Fightingstar Mawlong
Our thinking of science education should not be limited merely to measuring electric current, deducing an equation, dissecting a china rose or looking at test tubes within our school walls. Nor is science merely about technical know-how or productivity. More importantly, science literacy is about the ability to make sense of the world around us and to critically think about ideas and events we encounter in everyday life. Jawaharlal Nehru forcefully argued, “Science is a culture, a form of playfulness, providing a sense of discovery and excitement. It is a way of looking at the world and a way of training the minds to function according to the ways of science.” Also Cyril Hinshelwood, scientist who laid the groundwork for the discovery of the structure of DNA once said: “A common fallacy in much of the adverse criticism to which science is subjected today is that it claims certainty, infallibility and complete emotional objectivity. It would be more nearly true to say that it is based on wonder, adventure and hope.” And it is the spirit of scientific enquiry, adventure and sense of wonder that prompted an Indian Physicist, CV Raman to ask the question: “Why the deep oceans are blue?” He couldn’t have thought that this simple question would have a far reaching effect in modern science.
CV Raman passed the Financial Civil Service examination in 1907 and worked as Deputy Accountant General in Calcutta. Though a government official, his interest in science did not wane. He was an ‘efficient officer’ during the day and a ‘passionate scientist’ in his leisure time. It was in 1921 on his return from Europe that Raman’s scientific mind was tickled by the blue colour of the Mediterranean Sea. A natural childlike curiosity in Raman propelled him to question and to critically think about the blue opalescence of deep sea. In those days it was thought that reflection of light is the cause of the blue opalescence of oceanic waters. But the scientific temper in CV Raman refused to readily accept the existing theories and opinions unless he could fairly convince himself. So in that voyage, with his ‘Nicol prism’, he observed the waters and was convinced that reflection could not possibly be the only reason for blue colour of deep seas.
The Raman Effect in Science:
Back in Calcutta he began studying the scattering of light from various organic compounds. When light beams pass through a medium, a ‘small fraction’ of the beam goes shooting off in a new direction – this is called scattering. And CV Raman discovered that ‘a small fraction’ of this scattered light beam has energy (or colour) different from the incident light. This small fraction of scattered light whose energy is different from that of incident light is the ‘new type of light’ (or the new induced radiation) coming out of the medium. When light is scattered by the water molecules, the ‘new type of light’ has energy in the blue end of the spectrum more than in reds and yellows, hence deep sea appears blue. This phenomenon came to be known as the “Raman effect”.
The Raman Effect in Everyday life:
In a letter to her father, Rosalind Franklin, a Bio-technologist, said: “You look at science (or at least talk of it) as some sort of demoralising invention of man, something apart from real life, and which must be cautiously guarded and kept separate from everyday existence. BUT science and everyday life cannot and should not be separated.”So how is Raman Effect tied into the everyday? The essence of Raman Effect is that the energy of scattered light (or the “Raman pattern”) depends on the type of molecules of the substance. This means different substances have different Raman patterns, just like people have different fingerprints. One can therefore say that the Raman Effect “fingerprints the universe”. It helps in the ‘identification of substances’ just like fingerprints identify humans. Today the Raman scanners that detect the molecular structure of objects they are scanning are being used in Airport and Narcotic squads to detect drugs; by security experts to detect explosives; by police force in forensic work; and in medical science to detect pathogens. Researchers in Stanford University are busy experimenting with Raman scanner to detect cancer and in comprehensive blood tests. In short, Raman Effect enables us to instantly recognize everyday substances and to determine if the substance is RDX or TNT, heroin or chalk, glucose or cholesterol, etc, even in minute quantities.
The Raman Effect in education:
What is equally impressive is the ability of CV Raman to communicate science concepts without the help of jargons, in contrast to the ‘boring, dry and detached’ way that our teachers present science. Stories go that CV Raman’s lectures are gripping and thrilling to the children, to the general public as to the science community. His lectures are spellbindingly simple yet profound and always accompanied by demonstrations that would send a tingle down the students’ spine. He would bring out things in their simplest and most basic elements. His lecture of scientific phenomena would make his audience feel that they have seen it too. I believe Raman is one of those teachers who understood what the developer of first Atomic Reactor, Enrico Fermi said: “Once basic knowledge is acquired, any attempt at preventing its fruition would be as futile as hoping to stop the earth from revolving around the sun.”
I am tempted to pen down the way Raman explained his discovery to school children and the public. He had his audience picture a batsman wagging his bat forward and backward incessantly, and a ball is bowled at him. If the bat is moving backward at instant of contact between the ball and the bat, there will be incremental increase in velocity. In like manner, he would say, one can picture that when the light particles (or photon) hits the revolving electron in an atom there will be an incremental increase or loss in energy of light particle depending upon whether at the moment of contact the electron moves along the direction of movement of light particle or in opposite direction. The light particle of increased or decreased energy constitutes the ‘new type of light’ different from incident light beam. Of course this is an oversimplified and flawed analogy but it does serve the purpose of popularizing science.
Such is the ability of Raman to communicate the scientific phenomena, the scientific method and the scientific spirit that after listening to him about his discovery his aunt is said to have remarked: “I didn’t know it was so simple. I am surprised that such simple things should have merited international recognition.”
To mark the discovery of Raman Effect that earned CV Raman the Nobel Prize in Physics, India is celebrates February 28, every year as, ‘National Science Day’. I do hope that at least on this particular day, the word “popular” be brought back to “popular Science”. I also hope that the Science day Celebration would transplant in students a sense of wonder and inspire teachers to bring the wonder into science and make science inspiring. Let me end with what Max Weber, a German economist and sociologist, once said:“Inspiration plays no less a role in science than it does in the realm of art.” To me, CV Raman is an inspiration that could help people get science, get the feeling for science, and bring science alive.
(The writer is an alumnus of IIT Kanpur)