Tuesday, February 28, 2012

Commemorating a historical achievement – Raman, his effect and the National Science Day


I have never seen anyone who enjoyed science so much.  The sheer joy of seeing things and doing science filled him with exuberance and excitement.  He had an incredible zest for life.  He enjoyed his food, his jokes, his fights and quarrels.  Yet the enjoyment he had for his science was something apart.  In this pursuit it was as if his ego disappeared completely in the presence of effulgent Nature.  Yes, he was truly lost in the wonder and beauty of what he was trying to comprehend.

Biographer S Ramaseshan on C V Raman


[This write-up is based on the talks I have given over the last two decades, especially in schools and colleges and generally on 28th February, the National Science Day, on the significance of the day in relation to the life and work of India’s only native and home-grown science Nobel Laureate, C V Raman in whose research institute I had the privilege to work for my doctorate degree during 1977-81.  I am uploading this post to coincide with the day this year.]


28Feb28

28 February 1928 was the day when one of the greatest experimental discoveries in the annals of twentieth century science was definitively confirmed in a nondescript laboratory at the Indian Association for the Cultivation of Science (IACS) in Kolkata (then Calcutta) with some of the most primitive equipment then in existence by a group of physicists led by Chandrasekhara Venkata Raman (1988 -1970) and announced by him to the news media the very next day.  He followed it up with a formal lecture on the discovery, titled "A New Radiation", in the inaugural session of the South Indian Science Association on the 16th March 1928 at the Central College in Bangalore.  Incidentally, the lecture hall in the Cental College where this happened is named after him and I had the privilege of attending many classes and lectures in it as a postgraduate student of Physics in the late fifties.
 
As the news of the discovery spread and received swift confirmation from several of the better established laboratories around the world, C V Raman began to believe that it would fetch him the highest award one could dream of in the scientific world, something that he had the audacity to promise himself five years earlier!  So convinced and cocksure was he that the Nobel Prize for Physics in 1930 would be awarded to him that he had, in the words of his biographer, "... booked two tickets for himself and his wife in July that year to enable them to reach Stockholm in early December!". No, there is no evidence that any astrologer had predicted the outcome! Incidentally, Raman's biographer Dr S Ramaseshan, who was also a nephew as well as a student of Raman, vehemently rubbished any connection between the former and astrology while reacting to a mischievous innuendo from a 'noted astrologer' to such an implied link through his wife.

Raman was not disappointed with his outrageously confident expectation. The Nobel Committee did give its 1930 Physics Nobel Prize to him graciously and exclusively for his discovery that came to be recognized as the Raman Effect.  There are few instances in the history of the Nobel Prize of such a short gap between discovery and recognition.  The rest is history, marking one of the most memorable moments in the quest for scientific glory in India, a moment that is being commemorated as the National Science Day ever since it was so designated in 1986.

 
Raman the Physicist

Born near Trichy in Tamilnadu in 1888, Raman had his school education in Vishakhapatnam where his father taught Mathematics in a college and stimulated Raman’s early interest in both Mathematics and Physics.  Later he moved to Chennai (then Madras) and joined the famous Presidency College.  He was an exceptionally brilliant student in both Physics and English and obtained his B A degree when he was just 15.  While still an undergraduate, he had begun some meaningful research on Acoustics and Optics and published his first research paper at the age of 18.  He obtained his M A degree in Physics with the highest honours aged just 19.  Circumstances however compelled him to take up a lucrative position in the Indian Finance Department in Calcutta, a turn of events in some ways similar to that of Einstein.  His interest in Physics couldn’t be held back too long and he fortuitously made contact with the Indian Association for the Cultivation of Science where he spent most of his spare time doing some independent research with the meagre resources available. He soon came into limelight with his irrepressible talents and became a Professor of Physics in the Calcutta University in 1917, a switch that meant a considerable financial sacrifice.  In 1921 he attended a Universities Congress at Oxford and lectured on the theory of stringed instruments before the Royal Society of London.  In 1924 he was conferred the very prestigious Fellowship of the Royal Society (FRS).  At the invitation of Robert Millikan, he spent five months at the California Institute of Technology, USA the same year.  His historic discovery relating to light scattering, called the Raman Effect, came four years later and the Nobel Prize for it soon after.  Decades later, a grateful and independent India bestowed upon him the nation’s highest honour, the Bharat Ratna award, the same year it was instituted (1954).

Raman was such a strongly egotistic and domineering personality that he couldn’t get on well with the people who mattered in Calcutta, including the great astrophysicist Meghnad Saha, and decided to move to the Indian Institute of Science (IISc) in Bangalore to head its Physics department in 1933.  With this, the centre of gravity of Indian science shifted from its long standing base in Calcutta to Bangalore. Raman was later elevated to the directorship of IISc, but had to revert to his earlier position because of serious conflict with the governing council of the institute.  After his retirement in 1948 he founded his own institute for scientific research in Bangalore and staunchly maintained its administrative independence, uninfluenced by other considerations.  It was only after his death that the Raman Research Institute (RRI) came under the official umbrella of the Department of Science and Technology of the union government.

Here is a picture of Raman with his collection of awards at the Raman Research Institute in Bangalore.



The Raman Effect

It is not my intention here to give a detailed account of the discovery of the Raman Effect, its significance and  how it can be understood within the framework of quantum theoretical physics; nor is it my intention to delve into its extensive applications in science and industry following its rebirth after the invention of the laser.  However, a cursory treatment of the underlying principles may be in order.

When light is incident on matter in any state – transparent solids/liquids or a gas – the light photons are scattered by the molecules or atoms of the material.  A considerable fraction of the photons move away in different directions, without losing or gaining any energy in the process.  This is the well-known Rayleigh scattering phenomenon. Because of unchanged photon energy, and hence of the wavelength/frequency or colour, the scattering is said to be elastic. In very rare cases, the photon energy decreases or increases due to an electromagnetic interaction with the molecule/atom of the scattering material, thereby the wavelength or colour of the incident radiation is altered.  This is an inelastic scattering process, theoretically envisaged before Raman and his associates showed that it could indeed be achieved.  Because of the very low probability of such (Raman) scattering, extremely intense and monochromatic (single wavelength) sources of light such as mercury arc lamps with appropriate filters to produce nearly monochromatic light needed to be used.  The spectrum of the scattered radiation could be produced with a prism spectroscope and photographed with very long exposure times, yielding some extremely faint wavelength shifted spectral lines, in addition to a highly intense unmodified spectral line corresponding to the wavelength of the incident radiation.  The wavelength shift and the nature of the Raman scattered radiation depends on the nature and physical properties of the molecules of the material and can be determined through appropriate measurements.  The earliest experiments were done with clear liquids such as carbon tetrachloride, but later extended to transparent solids and gases as well.  The intensities and wavelengths of the scattered lines varied greatly, but the lines  corresponding to loss of photon energy were always more intense than those corresponding to a gain in energy.

Here is a picture of the spectrograph used by Raman and his team, exhibited prominently and proudly in IACS, whose old headquarters as well as the present one are also shown in the next picture.



When Raman confirmed the discovery he realized that what he had found was the optical analogue of a very similar process taking place with X-ray photons discovered earlier and known as the Compton Effect.  Significantly, the discoverer, Arthur H Compton of USA, had been awarded the Nobel Physics Prize just a year before.

Rejuvenation of Raman Effect

Despite the tremendous importance of the process, Raman scattering experiments and applications went into hiatus for want of monochrormatic light sources strong enough to produce significant results.  Raman’s research interests drifted away to other, more promising, areas where he made very valuable contributions, and stayed that way till the rest of his productive life.  But the invention of the LASER which made possible tremendously high intensity coherent sources of radiation in the sixties changed the scenario dramatically, though by then it was too late for Raman to re-enter the field. 

Laser Raman scattering became one of the most useful and productive techniques in scientific research and has remained so even now.  If anything, its importance and usefulness as an analytical tool for scientific and industrial applications has grown even more, with the development of portable and low cost Raman spectrometers employing the vastly more efficient ‘surface enhanced Raman scattering technique’, flexible fibre optic probes, integrated CCD video detectors and dedicated microprocessors for real time data acquisition and analysis.  The following picture shows one such ultra-compact commercial device:



Raman the Man

The following short statement by Dr Subodh Mahanti of Vigyan Prasar sums up Raman’s human side succinctly: “Raman was a very simple man. He was also a supreme egotist. But then in private conversation he often showed utmost humility.  He was a man of emotion.  He never bothered to suppress his feelings.  He could get violently angry.  He hurt many.  He feared no authority.  On some occasions he publicly wept like a child.  Raman had ‘all-too-human’ drawbacks in abundance.  But then he was an excellent physicist and totally devoted to the pursuit of science.” 

Few people ever seem to have seen Raman without his trade-mark turban and ill-fitting suit.  The former is seen as a symbol of his orthodoxy.  He was also a pure vegetarian and teetotaler. He had a refined sense of humour, one of the best illustrations of which was his purported remark  at the Nobel Prize after-dinner ceremony, “Ladies and gentlemen, you may all know the Raman effect on alcohol, but don’t try to find out the effect of alcohol on Raman.”

Raman was also a staunch nationalist.  His following remarks relating to the Nobel award ceremony are very significant: “When I sat in that crowded hall and saw the sea of western faces surrounding me, and I, the only Indian, in my turban and closed coat, it dawned on me that I was really representing my people and my country.  … When I turned round and saw the British Union Jack under which I had been sitting, I realized that my poor country, India, did not even have a flag of her own – it was this that triggered off my complete breakdown.”

It is interesting to note that Subrahmanyan Chandrasekhar, the great astrophysicist and Nobel Laureate,  did not have any great admiration for his uncle C V Raman and did not opt to work under his tutelage before he left India for greener pastures abroad.  He also thought that K S Krishnan, Raman’s best known associate at Calcutta, did not receive adequate credit for his contributions that resulted in the discovery of the Raman Effect.  In Chandrasekhar’s own words, Much of Raman's work relating to the discovery of the Raman Effect was carried out in collaboration with K S Krishnan.  But unfortunately, Raman and Krishnan fell out in the late forties and they became estranged.  It is a very unpleasant and unfortunate story.”  This certainly doesn’t imply that Krishnan deserved to share the Nobel award with Raman as has been made out by some distractors of the latter.

A Memorable Encounter

As a student of the Physics honours course at the Central College, Bangalore during 1956-59, I was as keen as my fellow classmates in meeting C V Raman and listening to him. One day some of us had the audacity to visit him at his institute and invite him to our department for a special lecture.  As soon as he heard our words, he flew into a violent rage, asked us to get out of his sight at once and virtually chased us out of the building.  Perplexed and deeply hurt at such a reception from someone we had all adored for his achievements, we were about to make a hasty retreat when he called us back in a commanding voice, regained his composure, put us at ease and explained why he had reacted so irritably.  Apparently, he had a grudge against the college and the thought of visiting it at the request of a bunch of irresponsible students was too much for him.  His temper cooled swiftly and he offered us a very reasonable compromise – that we should all visit him at his institute to hear a special lecture from him.  This was even better than what we had bargained for and, on the appointed day when all of us trooped in and awaited his presence in his spacious lecture hall, he gave us a masterly exposition of the theory of specific heats of solids, especially including his own recent contributions to it. In doing so, he castigated the work of the great German physicist Max Born, whom he had strongly patronized earlier at IISc,  as well as others who had preceded both.  To us it was a first-hand exposure to his complex and unpredictable personality to which Ramaseshan has alluded so frequently in his biography.
 
At the end of his talk,  I had the temerity born mainly out of ignorance and half-baked ideas to ask him if his theory was in any way connected with the famous Raman Effect.  I was too frozen stiff to understand his answer, but I do remember it was a patient, condescending and considerate one, making no mention of its irrelevance.   This was the other face of the great man.  Incidentally, Raman’s theory of specific heats was quickly dumped into the dustbin of history, a fate that befalls almost all great scientists sometime or other in their lives.

Subsequently, I had the opportunity to hear Raman’s lectures on two different occasions, once in my own city of Mysore to a packed gathering in the Maharaja/Yuvraja college complex. Though few in the audience really understood the contents, everybody had been mesmerized by his imposing personality.  It was not a particularly healthy sign for cultivating good science.
 
Working at RRI

As recounted elsewhere in my blog, I had the privilege of being attached to the Raman Research Institute during 1977-80 to pursue my doctoral work under the guidance of Prof S Chandrasekhar FRS, another nephew of C V Raman.  This gave me a ring side view of the institution that Raman had built up after his retirement from the Indian Institute of Science, Bangalore in 1948.  I could learn a great deal about Raman and his personality, including his love-hate relationships with other people,  from distinguished former students and assistants at the institute.  The museum of collections of butterflies, minerals, and expensive gems and precious stones he had built up was a notable sight in the RRI campus.  For good measure, I could actually lay my hands on his Nobel gold medallion and certificate of award, one of only two such repositories in the whole of the country.

Most lay visitors to RRI in those days invariably asked to see the Raman Spectrometer and were disappointed to learn that RRI didn’t have any such instrument, not even the one with which Raman had done his pioneering work, which is actually displayed at the IACS Kolkata.  Soon the situation was to change.  As part of my work on the study of the vibrational spectral characteristics of aligned liquid crystalline molecules, I needed to build and use a laser raman spectrometer at the Liquid Crystals Laboratory of RRI.  Prof Chandrasekhar had obtained a discarded traditional raman spectrometer built around a very good double reflection grating monochromator as a gift from abroad and I cannibalized it to isolate the monochromator and convert it to a laser Raman spectrometer using an existing powerful He-Ne laser souce, an imported photon counting system and some auxiliary equipment.  This not only served my purpose but also became a much needed show piece for the institution.  The excitement and thrill I derived from obtaining the first laser Raman spectrum of a liquid crystalline sample at RRI is permanently etched in my memory.  The success of my endeavour also provided me some bragging rights, not to speak of the blogging rights I am now indulging in.

28Feb78

To commemorate the 50th anniversary of the discovery of the Raman Effect, RRI had organized an international conference on Raman scattering and related topics in 1978. I was also associated with its organization and logistics to some extent. Many top notch researchers from abroad had participated, including Dr C K N Patel form Bell Labs, USA who had invented the highly powerful carbon dioxide laser for which I thought he deserved a Nobel Prize.  I had the opportunity to meet and talk to many of the distinguished delegates.   As part of the celebrations, Prof Ramasehan delivered the first C V Raman Memorial Lecture at the Indian Institute of Science and the subject of his lecture was none other than Raman himself, his multi-faceted personality and his scientific achievements. He summed up Raman’s scientific philosophy in these words: “To Raman, scientific activity was the fulfillment of an inner need.  His approach to science was one of passion, curiosity and simplicity.  It was an attempt to understand.  To him science was based on independent thought, combined with hard work.  Science was a personal endeavour, an aesthetic pursuit and above all a joyous experience.”

Here is a picture of the very impressive main building of RRI more or less as it was when I was attached to its almost invisible Liquid Crystals Laboratory far to its left.  RRI is located quite close to the sprawling Indian Institute of Science campus.


National Science Day

In 1986, the National Council for Science and Technology Communication (NCSTC), later renamed Vigyan Prasar, recommended to the Government of India the designation of February 28 for obvious reasons as the National Science Day (NSD).  The event is now celebrated all over the country in schools, colleges, universities and other academic, scientific, technical, medical and research institutions.  On the occasion of the first NSD (28 February 1987) NCSTC announced institution of the National Science Popularization awards for recognizing outstanding efforts in the area of science communication and popularization.
 
Conceived as an ‘autonomous’ organization, but fully funded by the central government, Vigyan Prasar’s primary objective is to promote/nurture a scientific temper and rational outlook among all categories of people through a variety of activities, particularly aimed at making NSD as productive as possible.  Considering the sorry status of science and science education in the country against the backdrop of stifling social customs and traditions, this is indeed an onerous responsibility, virtually impossible to achieve to any significant extent.  The fact that the organization works like most government departments further restricts its usefulness.  To be more effective, it needs to enlist the help of dedicated non-governmental voluntary organizations in a very big way and play an even more proactive role, exercising full functional autonomy and a much greater commitment to its primary objective. In trying to do so, it also needs to clearly elucidate for itself, in the context of it’s the primary objective, what constitutes scientific temper and rational outlook in different groups of people, including scientists and students of science, and what does not.

In the last few years Vigyan Prasar has been centering its efforts around a focal theme, usually of contemporary interest.  Last year, the theme was appropriately, “Chemistry in Daily Life”, to highlight 2011 as the International Year of Chemistry.  This year the theme has been, “Clean Energy Options and Nuclear Safety”, partially perhaps to deflect attention from the ongoing agitation against the Koodankulam nuclear power project.  Three sub-themes have been identified: (i) Nuclear Energy: A Clean, Reliable and Safe Energy Options, (ii) Alternative Energy for Sustainable Development, and (iii) Clean Energy Options – Choices for Tomorrow.   Undue importance appears to be given for Essay Writing, Slogan Writing and On-the-spot Poster Making competitions which are of rather dubious and superficial productive value, the last two being downright trivial.
 
Raman had believed that the only method of promoting science was by doing and living it in the real day-to-day world and not merely in scientific institutions, laboratories and universities and was contemptuous of professional organizers of science.  “for such people“ he said, “the so called organization of science becomes more important than science itself or its values”.  Here is much food for thought, particularly for Vigyan Prasar.

Regarding public awareness, there is very little dissemination of concrete information related to the NSD in the electronic and print media.  Like the numerous national festivals, NSD appears to be degenerating into yet another ritual in the national calendar.
  
Postscript

At the professional level, nobody has served the cause of science in independent India with greater commitment, conviction and example than C V Raman.  But, if the nation has to carry forward the torch he lighted as well as translate Nehru’s dream of science and science education as transformational agencies to combat the ills and evils of our society, a great deal more needs to be done than the merely ritualistic observation of one day in the year as a special day in the nation’s calendar. 

4 comments:

A V G Rao said...

Very nice

Chiranjeevi B said...

Superb writing as always.

Surya.S.P. said...

Very well written regarding the celebration of NSD, its significance & historical background ,Inspiring & interesting character of C.V.Raman. Your experience with the esteem personality is so thrilling.

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