Dr Purnima Sinha: Pioneering Physicist

While women in India had already begun marching forward in the fields of botany, chemistry and biochemistry in the mid-20th century, Physics was still very much an all-male domain. But this young lady with an unusual passion for the subject had no time to worry about glass ceilings. She was busy scouring surplus army equipment sold as scrap on the footpaths of Calcutta after the Second World War. Purnima Sinha was looking for spare parts to build the X-ray equipment she needed for her doctoral research.

Not long after that, this gritty and gifted youngster went down in the annals of Indian science as the first woman to earn a PhD in Physics from Calcutta University, in 1956. A protégé of Prof Satyendra Nath Bose, the celebrated theoretical physicist known for his work in quantum mechanics, she set many benchmarks as a scientist while also indulging her creative talents as an artist, writer and a musician.

In times when roles for women were rigidly defined, it helped that Dr Sinha was raised in a progressive family. Born on 12th October 1927 in Calcutta, her father, Dr Naresh Chandra Sengupta, was a constitutional lawyer and a writer who believed in equal rights for men and women. Dr Sinha attended Lake School for Girls; an institution founded by her eldest sister Sushama Sengupta.

With her siblings engaged in diverse and specialised fields, Purnima chose to study Physics in college and later at university. She acquired an MSc degree in Physics from Calcutta University and was most probably the only female student in her class.

Searching For Answers

The eager student soon found the impetus she was looking for in one of her teachers, Prof Bose, who noticed Purnima’s unusual interest in Physics and signed her on as his research student at the Calcutta University, where he had joined as Khaira Professor of Physics in 1945. Prof Bose had a group of researchers studying crystal structures using X-ray diffraction, one of the most pioneering areas of research at the time, and Purnima joined the group. Here’s an account of her work in her own words as quoted in Lilavati’s Daughters: The Women Scientists of India, an extraordinary collection of essays published by the Bengaluru-based Indian Academy of Sciences in 2008:

“Around the middle of 1951, I started working on my PhD with Prof S N Bose at the Khaira Laboratory in Calcutta. He advised me to carry out an investigation on the structure of clay from various parts of India. He suggested that I could use techniques of thermal and chemical analysis along with X-ray scattering and also suggested that I fabricate my own X-ray tube of the Coolidge kind so that the parts could be dismantled and put together at will.

At that time, about ten of us were involved in experimental research at the Khaira Laboratory. Each of us used to fabricate her or his own instruments according to individual needs. This was an unwritten rule in our laboratory. The more experienced research students used to initiate newer students in this mode of doing research and Prof Bose would routinely keep track of the problems we faced in the lab as well as our progress.

There was constructive cooperation between fellow students and people working in related departments. We all enjoyed the excitement of doing science in this manner. Because of the desire to hasten the pace of doing research, there has been a trend towards buying easily available, expensive, imported equipment. It would have perhaps been possible to develop a much more self-sufficient and confident scientific culture in the applied sciences in our country — in spite of the slower pace — if the ideal set by Bose had been followed.

The high-voltage transformer used for our X-ray equipment was fabricated in the applied physics department of our university. We had put together our X-ray equipment from the World War II surplus gathered in the lane behind Dr Bidhan Roy’s house. The rest of the parts were put together at the workshop in our department.

Our efforts in the X-ray laboratory finally led to a complete classification of about fifty clay samples into categories like Kaolinite, Montmorillonite, Illite, Vermiculitc, Chlorite and so on. The results of this investigation were put together in 1955. In 1956, Prof Bose retired from Calcutta University and we did further detailed X-ray studies of the structural characteristics of these clay samples in collaboration with Prof Kamalaksha Dasgupta.

Since that time, many publications on X-ray analysis of clay samples have come out of the Geological Survey of India, Central Glass and Ceramic Research Institute, Indian Institute of Technology and many other institutes. Few will realise that it was S N Bose, one of India’s finest theoretical physicists, who first initiated research in X-ray-based structural analysis of clay samples from different parts of this country.”

Fabricating one’s own laboratory instrument for research is unthinkable even in most modern, well-equipped labs today. But here was one of the first Indian women Physics research scholars looking for scraps from a World War II surplus to build her own X-Ray laboratory apparatus (we must remember that X-ray techniques were being applied to unravel DNA structure on other side of the globe around 1953). Most interestingly her research was funded by Assam Oil Company (research-industry collaboration in that era was unheard of).

Not only did she build it, but she also went on to study different types of clay from all over India.

– Her pioneering research on Indian clay had many applications, from X-ray studies to oil-drilling, to geology, to even art and pottery.

In fact, later in life, in 1963-64, Dr Sinha joined the Biophysics Department at Stanford University’s ‘Origin of Life’ project, which had an interface with her work. She compared the X-ray structure of clay with DNA patterns, geometrically, and was fascinated to find a connection.

Renaissance Scientist

Dr Sinha was multi-talented and explored each facet of her personality to the fullest. She was not only one of the first female students in the field of Experimental Physics in India, but she was also one of the first female students of renowned tabla player Pandit Jnan Prakash Ghosh. Clearly, ahead of her time, she mastered a percussion instrument that not many women choose to learn even today. She also learned Hindustani Classical Music from Yamini Ganguly and painting from the renowned painter Gopal Ghosh.

When she joined the Central Glass and Ceramic Research Institute, Dr Sinha continued her work on clay minerals and ceramic colours. Amazingly, she also moulded the material that she studied in artistic ways and learned clay modelling.

When not indulging her creative pursuits, Dr Sinha was translating science books into Bengali. It was something she probably inherited from her teacher, Prof Bose, who was a polyglot and believed in teaching subjects in the vernacular, in this case, Bengali. He set up an organisation Bangiya Bijnan Parishad (Bengal Science Association) to propagate scientific ideas in Bengali and Dr Sinha took this up as her life’s mission.

She translated Erwin Schrodinger’s Mind And Matter into Bengali in 1990; she wrote books on the life of Prof Bose; published a book titled Amar Katha (Bangiya Bijnan Parishad , a compilation of her interviews done in 1973, word-for-word, with Prof Bose; and authored a book on Prof Bose titled Bijnan Sadhanar Dharay Satyendranath Bose (Visva Vidya Sangraha – 1980).

Dr Sinha also wrote an article titled Satyen Bose-er Byaktitto O Mononer Dhara, which was published in the popular magazine Desh; she regularly contributed to Jnan O Bijnan, a scientific journal in Bengali published by Bangiya Bijnan Parishad (Bengal Science Association) who recognised her effort with an S. N. Bose memorial award in 2001; and contributed articles to The Journal of Asiatic Society of India –Science and Culture and the Economic & Political Weekly.

Her literary and academic interests did not stop here. Dr Sinha was married to eminent anthropologist Dr Surajit Sinha, who was also Vice-Chancellor of the Visva-Bharati University at Shantiniketan. She too had a keen interest in Anthropology. She wrote a book An Approach to the Study of Indian Music in 1970 and articles about folk music based on folk music recordings done in the field by her husband and her during anthropological field studies in the tribal regions of Purulia in West Bengal. She wrote an analytical article ‘Jarawa Songs and Vedic Chant: A Comparison of Melodic Pattern’ in The Journal of Asiatic Society in 2005 based on their field trip to the Andaman Islands in 1988. Together, they also started an informal school – Mela Mesha r Pathshala in Shantiniketan for tribal children.

Post-retirement, when she moved to Shantiniketan, Dr Sinha delivered a course in the Sangeet Bhavan on the Physics of Music and collaborated with potters there. A mural she created still adorns the wall of the Vice-Chancellor’s bungalow in Shantiniketan.

Memories of Our Mother

Dr Sinha’s phenomenal achievements were made while raising two daughters, Dr Sukanya Sinha and Dr Supurna Sinha, who are also successful physicists. She balanced the challenges of motherhood against her academic passions and creative pursuits extremely well, without sacrificing one for the other.

According to Dr Supurna Sinha: “I remember my mother as a person who was ever creative. From the youngest age, I would see her either engaged in making models of crystals with push pins and clay balls, or making a painting on the floor with enamel paint, or making artistic drawings suitable for cover designs of books or analysing music as part of her book on Indian music, or practising the tabla.

Around the end of her life, the image that stays in my mind is the sight of her sitting at a desk and painstakingly and passionately translating (Maxim) Kamenetskii's book, ‘Unraveling DNA: The Most Important Molecule of Life’. Her eyesight was very poor at that time and she had to use a magnifying glass to read the words. She used to discuss modern-day molecular biophysics of DNA with me since I was doing some related theoretical work at that time. She was a truly inspiring presence, a true amalgamation of science and art.”

Dr Purnima Sinha was not interested in awards and titles, and she never complained about glass ceilings. All that mattered to her was using her intellect and artistic abilities in the most productive and creative ways. Her advice to her grand-daughter, Roshni, was: “Stay creative all your life,” words she truly lived by.

Special thanks to Dr Sukanya Sinha and Dr Supurna Sinha for their inputs.

– ABOUT AUTHOR

Madhuri Katti is a Kolkata based physics teacher, heritage enthusiast and an aspiring writer.

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