One teaching of Dr. A.P.J. Abdul Kalam that I have always tried to follow is to ‘stay in circulation’, as he put it. By this, he did not merely mean travelling, attending meetings or remaining publicly visible. He meant keeping the mind in motion—meeting people, visiting institutions, listening to new ideas and allowing one’s own convictions to be questioned and renewed. Circulation prevents intellectual stagnation. It keeps experience connected with emerging realities.

Now that my health does not permit me to travel widely, I consider myself fortunate to live in Hyderabad, a city endowed with many fine institutions. I make it a point to visit some of them whenever possible and exchange ideas with people who have accomplished meaningful work in their chosen fields. Such visits are not formal obligations for me. They are opportunities to remain a student of life.

One such visit recently took me to the Banjara Hills campus of the Administrative Staff College of India (ASCI), where Dr. Subodh Kandamuthan, Professor and Director of the Dr. Kakarla Subba Rao Centre for Health Care Management, invited me to deliver an inaugural lecture to the new Batch 21 students of the PGDM (Hospital Management) programme.

It turned out to be one of those excellent visits that immediately occupy the ‘front seat’ of memory. The ASCI campus stands at perhaps one of the highest elevations in Banjara Hills. From there, one gets a panoramic view of KBR National Park, the precious green expanse that remains a vital lung for our fast-growing metropolis. The setting itself seemed to offer a lesson. As towers, roads and commercial establishments steadily encircle this surviving forest, one is reminded that progress must be measured not only by what we build, but also by what we choose to preserve.

The audience was pan-Indian: bright young students who had arrived at ASCI after walking meritorious academic paths in different parts of the country. Their presence represented India not merely as a geographical entity but as a confluence of diverse aspirations. They chose healthcare and hospital management at a moment when India’s health system is expanding rapidly but also confronting serious questions about affordability, access, ethics, and purpose.

What stayed with me most, however, was my tête-à-tête with Dr. Kandamuthan, a health economist. A native of Kerala with an MPhil from the Centre for Development Studies, Thiruvananthapuram, affiliated to Jawaharlal Nehru University, New Delhi, and a PhD in Health Economics from the Institute of Social and Economic Change, Bengaluru, his academic rigour is enriched by a perceptive grasp of India’s social complexities. In him, one can see the enduring social conscience of Indian society—a conviction that human welfare cannot be left entirely to the seasonal tides of capitalism.

Markets are powerful instruments. They can mobilise resources, encourage innovation and improve efficiency. But they cannot, by themselves, decide what a society ought to value. If profitability alone becomes the organising principle of healthcare, illness begins to acquire greater economic value than wellness. More tests, procedures, hospital admissions and interventions generate more visible revenue than fewer illnesses. The system may then grow financially while society becomes progressively less healthy.

From the stimulating and sagacious company of Dr. Kandamuthan, I could distil the need for a decisive paradigm shift: from an illness-based healthcare ‘industry’ to health economics rooted in wellness.

He drew attention to the wrong scorecard by which healthcare success is commonly measured. We count hospital beds, surgeries, diagnostic procedures, intensive-care facilities and insurance claims. These indicators are necessary, but they mainly tell us how much illness we are managing. They do not tell us how much illness we have prevented.

A hospital may perform thousands of cardiac procedures and be celebrated as a great success. But if many of those patients could have avoided severe disease through early screening, nutritional guidance, exercise, tobacco control, stress management and timely primary care, the larger health system has not truly succeeded. It has intervened efficiently at the end of a chain of failures.

Is not the cheapest hospitalisation the one that never happens?

This question brings us to the idea of the ‘Wellness Dividend’. In simple terms, a wellness dividend is the value created when individuals and communities remain healthy for longer. That value is not abstract. It is reflected in fewer hospital admissions, lower expenditure on medicines, reduced absenteeism, greater workplace productivity, longer working lives and less emotional and financial distress for families. It also frees public resources for education, sanitation, nutrition, housing and the treatment of illnesses that cannot be prevented.

Consider a person at risk of diabetes who receives timely advice, regular monitoring and sustained support to change diet and physical activity. If the onset of diabetes is delayed by ten years—or prevented altogether—the gain is much greater than the price of a few consultations and tests. The individual gains years of healthier life. The family avoids expenditure and anxiety. The employer benefits from greater productivity. Insurers face fewer claims. Hospitals retain capacity for those who genuinely need advanced care. The nation gains from the continued participation of a healthy citizen.

That combined value is the wellness dividend.

Yet our economic system often fails to recognise the wellness dividend because those who fund prevention may not receive its eventual savings. The benefits are dispersed across individuals, employers, insurers and governments—and may appear only years later. We readily calculate the cost of vaccination, screening or nutrition, but rarely the value of the illness prevented.

Realising the wellness dividend therefore requires incentives that give prevention measurable economic value. Healthy behaviour could earn lower insurance premiums, tax benefits or credits in a Personal Health Account. Employers could be rewarded for healthier workplaces, and primary-care providers for keeping communities well—not merely for treating them.

A Personal Health Account, linked securely with the Ayushman Bharat Health Account (ABHA), could serve as a lifelong health ledger supporting screening, vaccination, nutrition, mental wellbeing and chronic risk management, while safeguarding privacy and consent. It could also recognise citizens economically for remaining healthy, rather than paying only after serious illness occurs.

Hospitals and advanced care remain indispensable, but they must rest upon a vibrant primary-care system—the economic and moral foundation of modern healthcare. Without it, patients reach specialist care too late, illnesses become costlier to treat, and expenditure rises without proportionate improvement in public health. Family physicians, nurses, community health workers, nutritionists and local diagnostic centres may prevent more suffering than sophisticated hospitals can later repair; their contribution must therefore be recognised, measured and rewarded.

The movement from the economics of illness to the economics of wellness is ultimately a change in what we choose to celebrate. Do we celebrate only the dramatic rescue in the intensive-care unit, or also the quiet work that prevented a thousand people from entering it? Do we reward only the procedure, or also the years of healthy living that made the procedure unnecessary? Do we regard health expenditure as money spent after disease appears, or as an investment in human capability?

These are not merely philosophical questions. Nor are the Personal Health Account and the Wellness Dividend utopian ideals. They are practical concepts articulated by an astute economist whose thinking remains grounded in the realities of his country and its people.

India needs many more such conversations. It must also cherish institutions such as ASCI—places where administrators, economists, healthcare professionals and young managers can meet beyond their disciplinary boundaries and reconsider the assumptions governing public systems. Institutions acquire greatness not through buildings alone, but by creating spaces where experience encounters inquiry and ideas become instruments of service.

We must equally celebrate people such as Dr. Subodh Kandamuthan: true sons of the soil whose education has taken them across institutions and disciplines, but whose hearts continue to beat with their people. Their scholarship does not distance them from society; it returns them to it with greater responsibility. In their work, knowledge remains accountable to the ordinary citizen.

As I left the high-ground ASCI College Park campus, with KBR Park spread below and a new generation of healthcare managers beginning its journey, I felt renewed by Dr. Kalam’s counsel to stay in circulation. Sometimes circulation is not about travelling far. It is about reaching the right place, meeting a thoughtful person and returning home with an idea capable of changing how we see the future.

Every year on September 5, India celebrates Teachers’ Day in memory of Dr. Sarvepalli Radhakrishnan (1888–1975), one of modern India’s most distinguished philosophers, teachers and statesmen. His life demonstrated that scholarship need not remain confined to the classroom; at its best, it can illuminate public life and guide a nation.

Dr. Radhakrishnan taught at several eminent institutions, including the University of Oxford, and was knighted in 1931. He served as Vice-Chancellor of Andhra University from 1931 to 1936 and of Banaras Hindu University from 1939 to 1948. After India attained independence, he became the country’s ambassador to the Soviet Union from 1949 to 1952, Vice-President of India from 1952 to 1962, and President from 1962 to 1967. Yet, through all these distinctions, he remained fundamentally a teacher. It is only fitting that his birthday became an occasion not merely to remember an illustrious life, but to honour the countless men and women who quietly shape the nation’s intellectual and moral character.

This year, Dr. Srivari Chandrasekhar, my long-standing friend and an eminent synthetic organic chemist, hosted a Teachers’ Day dinner at Dakshin, the iconic restaurant at ITC Kakatiya in Hyderabad. A large gathering of teachers attended, many from local schools and colleges, where they teach with financial support from Dr. Chandrasekhar and his wife, Bharathi. It was one of those rare evenings whose warmth remains long after the lights have dimmed and the tables have been cleared.

There was something deeply moving about the simplicity of the teachers gathered there. They carried no outward signs of power or privilege. Yet they possessed an unmistakable dignity—the quiet aura of people who have made useful work their livelihood and the growth of others their reward. Their lives may seldom receive public attention, but their influence travels through generations. A teacher may spend decades in the same classroom, yet through the students who pass through it, that classroom reaches laboratories, hospitals, industries, universities, public institutions and distant countries.

It is a sad truth that teachers in India are often underpaid. Their compensation rarely reflects the weight of the responsibility placed upon them. But a good teacher receives another kind of wealth: the affection of students, the respect of families and the knowledge that something of his or her mind and spirit will continue to live in the minds of others. This, of course, does not excuse society from paying teachers fairly. Respect cannot settle household expenses, nor can gratitude substitute for institutional support. Yet the love accorded to a good teacher remains one of the purest forms of recognition available in human life.

Dr. Chandrasekhar and Bharathi honoured me that evening as a teacher. It was indeed a humbling moment. I have never considered myself an academician in the formal sense. Except for a decade-long association as an adjunct faculty member at the School of Management Studies, University of Hyderabad, I possess few academic credentials that might justify such recognition. Most of my learning and work took place in laboratories, technology missions, public projects, books and conversations with remarkable people.

But perhaps teaching is larger than an academic appointment. A teacher is anyone who helps another person see more clearly, think more rigorously or act with greater confidence. A scientist explaining a failure to a young colleague is teaching. A physician listening carefully to a patient is teaching a young intern. A senior engineer who allows a junior colleague to attempt a difficult task is teaching. An author who places a hard-earned insight before an unknown reader is also, in some measure, teaching. Seen in this way, teaching is not merely a profession. It is a way in which knowledge accepts responsibility for the future.

Another satisfying part of the evening was meeting some of Dr. Chandrasekhar’s former students, now accomplished scientists in their own right. Over his three-decade academic career, he guided 97 scholars to complete their PhDs—an extraordinary achievement. Each doctorate represents far more than a thesis, a viva voce examination and a degree. It embodies years of experiments, failed chemical reactions, uncertain results, revised hypotheses, rejected manuscripts and the slow cultivation of scientific judgement.

Dr. Chandrasekhar also remembered, with equal warmth, another 13 students who had registered under his supervision but could not complete their doctoral work. For different personal, professional or academic reasons, they had to leave midway through the several years of demanding work typically required to complete a PhD. His remembrance of them was important. A teacher’s responsibility is not limited to those whose names appear successfully on a list. Those who could not complete the journey are also part of the teacher’s story. Education must retain compassion for unfinished journeys, for life does not always cooperate with ambition.

Of the 97 students who earned their doctorates under him, only about half pursued academic careers. The others entered industry, carrying their scientific training into the practical world of products, processes and manufacturing. More than 30 now work abroad, many in major chemical companies. Their paths remind us that the value of a doctoral education cannot be measured only by the number of professorships it produces. A scientist trained to observe accurately, question assumptions, endure uncertainty and learn from failure carries those capacities wherever he or she goes.

After retiring from the distinguished position of Secretary of the Department of Science and Technology, Government of India, Dr. Chandrasekhar did not retire from science. Through his association with GITAM University and PI Health Sciences, he continues to teach, mentor and participate in research. He hosted me at both places, and the vibrancy of the people around him struck me. Young researchers approached him freely. Questions moved easily across age and hierarchy. Ideas were discussed without ceremony. That atmosphere revealed something essential: a true teacher does not create dependence on himself; he creates confidence in others.

The continuity of this tradition became even more visible when Dr. Chandrasekhar spoke of his own teacher, the legendary Dr. A. V. Rama Rao, who guided 108 PhD scholars, including Dr. Chandrasekhar himself. His students once presented him with a unique Periodic Table containing 108 elements, each represented by the photograph of one of his doctoral scholars. It was a beautiful scientific metaphor. Just as the elements combine to create the material world, those students had carried their teacher’s influence into numerous institutions, disciplines and industries.

On the morning of Teachers’ Day, Dr. Chandrasekhar visited his guru. In speaking of Dr. Rama Rao’s achievement, he made his own remarkable record of 97 PhDs appear almost modest. But this is precisely how a great lineage of learning sustains itself. The accomplished student does not outgrow gratitude. He honours the teacher by extending the tradition, improving upon what he received and passing it forward. In Indian civilisation, the guru–shishya relationship has never been understood merely as a transaction of information. It is a living chain of trust, discipline, example and intellectual inheritance.

India’s chemical and pharmaceutical achievements offer visible evidence of this chain. The country has developed formidable capabilities in active pharmaceutical ingredients, generic medicines, agrochemicals and process chemistry. Its chemical industry is among the world’s most capable and competitive. Behind every successful molecule manufactured at scale stands an often-invisible community of teachers and students: professors who established laboratories with limited resources, research scholars who repeated experiments late into the night, technicians who refined processes, and industrial scientists who converted laboratory insight into reliable production.

The Indian scientific system has its share of shortcomings. Laboratories may face shortages of equipment and resources. Universities may struggle with bureaucracy. Research scholars may endure uncertain fellowships, inadequate infrastructure and long periods without encouraging results. Yet the system continues to produce scientists of international standing. This is not a reason to ignore its deficiencies. It is a reason to recognise the extraordinary human qualities that keep it alive despite them

During dinner, I asked Dr. Chandrasekhar what makes science—and especially the teaching of science at the highest level—truly great. His answer was concise: teacher commitment and student resilience.

The teacher’s commitment is not fulfilled merely by delivering lectures or signing progress reports. It means standing by a student through periods of confusion; protecting intellectual freedom while insisting on rigour; recognising potential before achievement makes it visible; and knowing when to guide, when to challenge, and when to step aside. A committed teacher does not provide easy answers to every question. He helps the student acquire the courage and discipline to pursue the answer independently.

The student’s resilience is the answering virtue. Research repeatedly confronts the young mind with failure. Experiments refuse to behave. Instruments malfunction. Papers are rejected. Promising ideas collapse under evidence. Resilience is not stubborn repetition; it is the capacity to absorb disappointment, learn from it and return to the problem with a better question. The student must remain teachable without becoming submissive, confident without becoming arrogant, and ambitious without losing integrity.

Commitment without resilience can produce frustration; resilience without commitment can become lonely endurance. But when the two meet, education becomes transformative. The teacher holds the lamp steady, while the student develops the strength to continue walking. One offers faith before success; the other justifies that faith through perseverance.

That Teachers’ Day dinner therefore became more than a celebration. It became a reminder of how civilisation renews itself. Nations are not built only in parliaments, factories or markets. They are built wherever one generation accepts responsibility for the next—where a teacher refuses to give up on a student and where a student rises once more after failure.

Blessed are such teachers. Blessed, too, are the resilient students who honour them not merely with flowers and words, but by carrying their learning into the world and making it fruitful.

Among the great images created by Indian civilisation, few possess the visual authority of the Chola Nataraja. Shiva dances within a circle of flame, one foot planted upon ignorance and the other lifted in liberating grace. His hair flies outward, his arms extend in several directions, yet his face remains serenely composed. Motion and stillness, destruction and renewal are held together in one form. It is not merely a god dancing, but a philosophical account of a universe continuously becoming, dissolving and beginning again.

The Chola Nataraja is also remarkable as a product of metal engineering. The sculptor had to transform an extraordinarily complex wax model—with extended arms, slender fingers, flying locks, flames, ornaments and an asymmetrically positioned body—into a durable copper-alloy image. Molten metal had to flow into every extremity before solidifying; the mould had to preserve minute details while containing the molten alloy; and the finished sculpture had to remain stable despite appearing to balance on a single dancing foot.

The precise construction method varied with the idol’s size and design. In some monumental examples, Shiva, the dwarf Apasmara, an icon of spiritual ignorance, ego, and forgetfulness of one’s true divine nature, and the flaming aureole were solid-cast together, while the lotus pedestal and rectangular plinth were cast separately and mechanically attached. What appears to the observer as a single, effortless composition could therefore be a carefully planned assembly of cast and joined components.

The engineering began long before the furnace was lit. The figure was constructed according to a canonical system of proportion in which the body was divided into modules that regulated the dimensions of the head, torso, limbs, hands, and overall stature. These proportions were not merely aesthetic conventions. They also controlled the length, position and mass of projecting components.

The raised leg extends across the body, four arms spread into the surrounding space, and locks of hair radiate from the head. If these elements were disproportionately long or heavy, they would increase the bending moments acting at the ankles, shoulders, wrists and hair junctions. Proportional geometry therefore helped the sculptor reconcile visual dynamism with physical stability.

In the living bronze-casting tradition of Swamimalai, the wax mixture has commonly been prepared from approximately equal proportions of beeswax and powdered dammar resin, softened with a small quantity of groundnut or sesame oil. Beeswax provides plasticity; the resin increases firmness and helps the model retain sharp edges; and the oil modifies its workability. The result is a modelling material that can be shaped by hand while remaining sufficiently stable to hold intricate detail.

Wax channels were then attached to the model. Some became pouring passages, or sprues, while others formed runners that distributed molten metal towards distant or delicate regions. Traditional prescriptions and surviving workshop practices often place these channels at the back, shoulders, neck and head, where the marks left after their removal would be least disruptive.

Their position was critical. Insufficient feeding could leave a hand, finger or flame incomplete. Poorly arranged passages could create excessive turbulence, trap gases or cause separate streams of metal to meet only after they had cooled too far to fuse properly. The channels therefore had to deliver metal rapidly and evenly while allowing displaced air and gases to escape.

The clay mould had to perform several apparently conflicting functions. Its inner surface needed to be fine enough to reproduce delicate facial modelling and ornament. At the same time, it had to be porous enough to release gases, refractory enough to withstand contact with molten copper alloy and mechanically strong enough to resist cracking or bursting during the pour.

The principal constituent of most early South Indian bronze images was copper, often forming around four-fifths or more of the alloy. Tin and lead were present in varying proportions, while zinc, silver, gold and other metals might occur in smaller or even trace quantities. The ritual term pancha-loha, meaning ‘five metals’, should therefore not be understood as a single, universally fixed metallurgical formula.

Tin increases copper’s hardness and strength, although excessive tin can make the alloy brittle. Lead has only limited solubility in copper and tends to remain dispersed as small globules, but it can improve the apparent fluidity and castability of the molten alloy. It may therefore help the metal enter narrow passages and reproduce fine details.

Yet some outstanding bronzes contain relatively modest quantities of both tin and lead. Their successful casting depended not merely upon a highly fluid alloy, but upon the entire foundry system: careful mould preparation, accurate temperature control, intelligent gating and rapid, well-directed pouring.

A Nataraja is especially difficult to cast because its sections vary greatly in thickness. The massive torso retains heat and remains molten longer than the slender fingers, flying hair and individual flames. If these thin regions solidify before they have filled completely, the result is a misrun—an incomplete casting. If two partly cooled streams meet, they may produce a cold shut, a weak seam where the metal fronts fail to fuse fully.

Thicker sections created additional challenges because metal contracts as it cools. Without continued feeding from reservoirs of molten alloy, shrinkage cavities, gas porosity, residual stresses, cracking and distortion could develop. The mould and gating system therefore had to ensure rapid filling of delicate features followed by progressive solidification, keeping heavier regions supplied with liquid metal long enough to compensate for contraction. The sculptor-founder was controlling not only the bronze’s form, but also the sequence in which it became solid.

The structural achievement is equally impressive. Visually, Shiva appears to float upon one leg. Mechanically, however, the load is distributed through a more complex system. The principal gravitational force passes through the supporting leg, the figure of Apasmara, the footplate and the pedestal. The entire geometry of the dancing Shiva is composed around this gravitational axis: although the limbs, hair and surrounding aureole extend dramatically into space, their masses counterbalance one another so precisely that the sculpture’s combined centre of gravity is brought into alignment with the single supporting leg. What appears to be movement at the edge of instability is, in fact, a remarkable achievement of static balance.

The Nataraja is therefore not a statue precariously balanced upon a single point of support. It is a carefully integrated structural system that conceals its engineering within its iconography. Apasmara becomes a compression-bearing element; the lotus pedestal becomes a load-distributing foundation; hair and ornamental links act as braces; and the aureole helps unite the composition mechanically as well as visually.

Chola craftsmen did not possess modern phase diagrams, finite-element models or computational fluid-dynamics software. Their knowledge was embodied in measurements, materials, proportions, workshop sequences and accumulated experience. A failed finger indicated inadequate feeding. A cracked investment revealed unsuitable clay, excessive moisture or insufficient drying. Porosity could indicate trapped gases, turbulence or inadequate control of the melt.

Over generations, success and failure produced a systematic body of empirical knowledge, transmitted through apprenticeship and grounded in close observation, disciplined practice and an intimate understanding of materials. This tradition remains alive in Swamimalai, where master sculptors and bronze casters from hereditary craft families continue to create sacred images through the lost-wax process, preserving historic proportions, materials and foundry techniques.

The continuing capacity of this tradition was dramatically demonstrated by the Nataraja installed at Bharat Mandapam for the 2023 G20 Summit in New Delhi. Standing 27 feet high including the pedestal and weighing approximately 18 tonnes, it was produced by traditional master craftsmen from Swamimalai using lost-wax casting and canonical proportions. Its scale was modern, but the fundamental sequence—proportional design, wax modelling, refractory investment, dewaxing, alloy melting, pouring and hand finishing—continued the historic South Indian foundry tradition.

The Chola Nataraja is thus not simply bronze shaped into a beautiful deity. It is geometry translated into wax, wax transformed into a refractory void, and that void filled through the controlled movement of fire and molten metal. Its deepest engineering triumph lies in making immense technical difficulty disappear.

The observer sees neither sprues nor solidification fronts, neither shrinkage cavities nor hidden load paths. One sees only Shiva dancing—bronze transformed into rhythm, mass into apparent weightlessness, and metallurgical knowledge into spiritual form.

I recently visited PI Health Sciences Ltd. at Genome Valley, Hyderabad, at the invitation of my long-standing friend, Dr. S. Chandrasekhar, who joined the organisation as Chief Scientific Advisor after his superannuation as Secretary, Department of Science and Technology, Government of India. Given the freedom to choose my subject, I decided to speak on From Molecules to Missions, and, building upon my continuing engagement with artificial intelligence, made Science Beyond Silos in the AI Era my theme.

The conference room, with a capacity of about a hundred, was filled to capacity. Scientists from PI Health Sciences facilities at Panoli, Jaipur, Ankleshwar and Udaipur joined online. For a non-chemist to stand before such a formidable gathering of chemists was initially a little awkward for an engineer like me.

I therefore began with engineering.

Chemistry, I said, cannot remain in the flask. For a chemical reaction conceived by a scientist to become an industrial reality, engineering must create and control the required temperature, pressure, flow, mixing, separation and containment—precisely, repeatedly and safely. That simple acknowledgement produced an instant bonhomie. I could then change tracks and make the larger point: in the modern world, chemistry cannot remain separated from engineering, biology, environmental science, medicine—and increasingly, AI.

The hour then passed like a breeze.

Using AI-generated slides, I began with a proposition that sounds almost philosophical but is fundamentally scientific: molecules have an afterlife. What we create does not simply vanish after its intended use is over. Molecules may degrade, transform, bind to other substances, migrate, accumulate or persist. Their journey can continue long after the product they were designed for has been discarded.

Consider the chemicals entering soil through fertilisers, herbicides and pesticides; industrial chemicals discharged onto land and water; or pharmaceuticals and their metabolites leaving the human body and entering sewage systems. Some are removed or broken down, but others can survive treatment, move through water and soil, interact with organisms and reappear in unexpected places.

What goes down does not simply go away.

Groundwater makes this particularly clear. Landfill leachate, industrial effluents and agricultural chemicals can migrate through soil and rock and, under the wrong conditions, reach aquifers. Once there, the problem is no longer one of chemistry alone. Hydrology must tell us where the water moves. Geology determines the pathways. Agriculture must examine uptake by crops. Toxicology and medicine must assess exposure and consequences. Public policy must decide acceptable risk levels and how best to prevent or mitigate the associated harms.

The food web carries the story further. Certain persistent pollutants can accumulate in organisms and, in some cases, become increasingly concentrated at higher trophic levels. What begins invisibly in water may pass into plankton, fish, larger predators and ultimately human beings. The food web remembers what our production and disposal systems may forget.

Then there is plastic.

Plastic is one of modern chemistry’s great achievements precisely because it is durable, versatile and inexpensive. Yet the durability that created its enormous utility has also created its environmental persistence. Larger plastic objects fragment into microplastics and still smaller particles; fragmentation is not disappearance. Such particles are now found across marine and terrestrial environments and have been detected in human tissues as well. The precise health consequences are still being investigated, and science should resist premature claims. But the ubiquity of exposure itself gives us sufficient reason to take prevention, materials design and waste management far more seriously than we presently do.

This led me to a more uncomfortable question. Have we built parts of modern civilisation in which we first create exposures and lifestyles that favour chronic disease and then build increasingly sophisticated systems to treat their consequences?

The diabetes epidemic, for example, cannot be attributed simply to sugar—humans have consumed sugars for millennia. But it certainly cannot be separated from the modern ability to refine, concentrate, manufacture and distribute calorie-dense foods on an unprecedented scale, combined with sedentary living and other metabolic risks. Similarly, rising concern about environmental exposures and cancers in younger populations deserves rigorous investigation, not sensational attribution to a single culprit. The scientific responsibility is to ask the question early enough, collect the right evidence and act when the evidence becomes persuasive.

The same principle applies to climate change. Carbon capture is scientifically feasible and has already been demonstrated in several settings. But capturing carbon dioxide is only one part of the problem. It must then be compressed, transported and stored securely for very long periods. Economics, infrastructure, geology, monitoring, regulation and public confidence immediately enter the picture. Once again, no discipline owns the problem.

This was the central message of my lecture.

Plastic pollution is not merely polymer chemistry. Groundwater contamination is not merely hydrology. Food safety is not merely biology. Climate change is not merely atmospheric science. The problems have already crossed the boundaries between our departments. Our science must now do the same.

And this is where AI offers an extraordinary opportunity.

AI’s greatest contribution to science may not ultimately be faster calculation. It may be its ability to connect what science has separated—datasets residing in different institutions, models built by different disciplines, research literature too vast for one individual to master, and relationships visible only when information is examined across scales.

Chemistry can speak to biology. Environmental measurements can connect with health outcomes. Molecular properties can be combined with hydrology and land-use data to predict environmental fate. AI-enabled surveillance can identify emerging contamination hotspots, detect weak signals and help us move from discovering damage after it has occurred to anticipating pathways before harm becomes widespread.

In other words, from prediction to prevention.

That requires a change in the scientist’s question. We must continue asking, Does this molecule work? But we should add: Where will it eventually go? What will it become? What will it encounter? And what might it do there?

We must begin to design for fate, not merely for function.

After the lecture and an engaging Q&A, we continued the conversation over an excellent working lunch. It gave me an opportunity to interact more closely with Dr. Dinesh Chaurasiya, Dr. Prathama Mainkar and Dr. Abhishek Sud, among other outstanding scientists who have helped build PI into a leading Contract Research, Development and Manufacturing Organisation, particularly in the agrochemical domain. Their depth of scientific experience and the range of the discussion reinforced the very point I had tried to make in my lecture: important problems are increasingly solved not within disciplinary compartments, but through conversations across them.

Dr. Chandrasekhar, with his trademark wit, provided the perfect closing line. “Karl Ziegler and Giulio Natta received the 1963 Nobel Prize in Chemistry for their discoveries in the chemistry and technology of high polymers”, he said. “Now depolymerisation is waiting for one. Whoever really gets rid of plastics may take it home.”

Behind the humour lies a serious mission.

The scientist’s responsibility does not end when the molecule succeeds. It extends to what that molecule eventually does in the world.

Our molecules. Our missions. Our world. Our responsibility.

I returned home with a quiet sense of fulfilment—almost like a pilgrim returning from a place of learning and purpose. PI Health Sciences had seemed to me not merely a laboratory or an enterprise, but a portal of scientific excellence, where knowledge is being transformed into possibilities for a better world.

Recently, I had the pleasure of attending a family dinner hosted by Vishal Arora, a young CEO and a friend of my son Amol. His wife’s parents were also present. Although they all come from New Delhi, they seemed to carry with them something of the city’s older culture—refinement in living, warmth in social relationships and a deep appreciation of food. We spent nearly four hours together, but the evening passed like a mild breeze.

As we were leaving, Vishal, who is also an accomplished chef by passion, presented me with a small glass jar of pickle. He invited me to choose from a remarkably wide variety that he had prepared and curated himself. I selected a dried raw-mango pickle seasoned prominently with black mustard seeds—rai in Hindi. It contained only a minimal quantity of mustard oil, used less as a heavy covering than as a medium for carrying the flavour and aroma of the spices.

Pickles are almost inseparable from Indian food. A small portion may accompany an otherwise simple meal of dal, rice, roti, curd or khichdi and transform its entire sensory character. Vishal’spassionately curated collection made me reflect upon the considerable science concealed within this ordinary-looking food. A pickle is not merely a fruit or vegetable immersed in salt, oil and spices. It is a deliberately constructed biochemical environment in which water, acidity, oxygen, microbial life, plant enzymes and aromatic molecules are brought into a controlled relationship.

The first principle of pickling is the management of water. Fresh mango, lemon, chilli, carrot, radish, amla, garlic and most other vegetables contain enough available water to support the growth of bacteria, yeast and mould. Salt begins the preservation process through osmosis. When salt surrounds the plant tissue, water moves out of the cells towards the region of higher solute concentration. This produces the familiar brine that appears even when no water has been added. The removal and binding of water reduce its availability to microorganisms. At the same time, salt penetrates the plant tissue, changing its texture and creating conditions in which some organisms are inhibited while more salt-tolerant species may survive. Studies of vegetable fermentation show that salt concentration influences not only preservation but also the composition of the microbial community, the speed of fermentation and the final flavour. Excessive salt may inhibit even desirable fermentative organisms, while insufficient salt can permit spoilage microbes to dominate.

Drying, as in the mango pickle Vishal gave me, adds another layer of protection. Sun-drying or controlled dehydration removes a substantial part of the fruit’s moisture before it enters the jar. The biochemical reactions that require available water consequently slow down. Enzymes become less active, microbial multiplication becomes difficult, and the mango acquires a concentrated sourness and a resilient, chewy texture. Drying does not sterilise the fruit, but it makes the internal environment much less favourable to rapid decomposition.

Acidity is the second great principle. Raw mangoes and lemons naturally contain organic acids, while many recipes add vinegar or lemon juice. In genuinely fermented pickles, naturally occurring lactic acid bacteria metabolise sugars present in the fruit or vegetable and convert them largely into lactic acid. As acidity increases and the pH falls, many undesirable organisms are progressively excluded. Fermentation also creates new flavour molecules, which is why a fermented pickle tastes more complex than a vegetable merely dipped in vinegar. Traditional Indian pickles have yielded diverse lactic acid bacteria, yeasts and other microorganisms, demonstrating that the pickle jar can become a small, evolving ecosystem.

It is important, however, not to call every pickle ‘fermented’. Many Indian achaar preparations are preserved primarily through a combination of drying, salt, natural or added acid, spices and oil. Their purpose is to prevent microbial activity rather than encourage a controlled fermentation. Similarly, not every homemade pickle should automatically be described as probiotic. Researchers have isolated organisms with potentially beneficial properties from certain traditionally fermented mango pickles, but such findings relate to particular strains studied under defined conditions. Whether those organisms survive storage, remain present in sufficient numbers and withstand digestion must be demonstrated before a specific pickle can legitimately be regarded as probiotic.

Mustard seeds bring a small chemical drama to the pickle jar. Black and brown mustard contain sinigrin and an enzyme called myrosinase, which are stored separately within the seed. Crushing and moistening the seed brings them together, producing allyl isothiocyanate—the volatile compound that gives mustard its sharp, nose-clearing bite. It can also inhibit some bacteria and fungi, allowing rai to contribute both flavour and modest chemical protection. Yet it is only one part of the preservation system.

Mustard oil spreads spice aromas, coats the fruit or vegetable, and helps limit contact with air and moisture. The oil layer at the top of a jar also discourages surface contamination. But oil alone cannot preserve a wet, poorly salted or insufficiently acidic pickle. Safety and stability arise from several barriers working together: salt, acidity, reduced moisture, antimicrobial spices, limited oxygen and clean handling.

The glowing colours of Indian pickles are also products of chemistry. Turmeric owes its golden hue mainly to curcumin, a pigment that can also slow some oxidation reactions. In experimental studies on pickled cucumbers, turmeric reduced the formation of volatile aldehydes associated with oxidative deterioration. Chillies add red carotenoid pigments and capsaicinoids, the compounds responsible for their heat. Fenugreek, fennel, cumin, ajwain, ginger, garlic and asafoetida contribute their own essential oils, sulphur compounds, phenolics, bitters and aromatic molecules. Together, they create a rich flavour system: acids provide sourness, sodium ions saltiness, plant compounds bitterness, mustard and chilli pungency, and numerous volatile molecules the characteristic aroma.

Time then works quietly within the jar. Salt and acid move deeper into the mango, while spice compounds pass into the oil and plant tissue. Sharp individual flavours gradually blend and soften. Some aromas fade, new ones emerge, and the texture changes as cell membranes and cell-wall materials are altered. A freshly prepared pickle and a matured one may contain exactly the same ingredients, yet taste remarkably different. Maturation is therefore not merely waiting; it is a continuing series of physical and biochemical exchanges.

India also has a smaller but notable tradition of non-vegetarian pickles, particularly those made from fish and prawns in coastal and southern regions. The basic principles remain the same—thorough cooking, moisture reduction, salt, acid, spices and oil—but the chemistry is more demanding. Protein-rich foods can support microbial growth, while animal fats are vulnerable to oxidation and may develop rancid flavours. Careful cooking, scrupulous hygiene, minimal residual moisture and proper storage are therefore essential to the pickle’s safety, quality and shelf life.

Pickles are best enjoyed in modest quantities. Their concentrated salt, acidity, oil and pungency allow even a small spoonful to stimulate the appetite, sharpen flavours and provide a lively contrast to the rest of the meal. Larger quantities, however, may add excessive salt and oil while overpowering the food they are meant to complement.

The science of pickles offers a useful lesson about tradition. Traditional practice should neither be romanticised as infallible nor dismissed as primitive simply because its practitioners did not speak in the language of pH, water activity, osmotic pressure, glucosinolates or microbial ecology. Through generations of observation, households learned that mango must be dried, jars must remain clean, moisture must be controlled, salt must be sufficient, spices must be properly prepared, and the contents must be protected from air and contamination.

Science does not diminish this inheritance. It reveals its architecture. The jar that Vishal placed in my hands contained mango, mustard, salt, oil and spices—but it also contained osmotic gradients, organic acids, enzyme reactions, volatile antimicrobials, antioxidant molecules and the memory of countless domestic experiments. What appears at the table as a modest spoonful of achaar is, in reality, a beautifully balanced exercise in biochemistry.

A recent knowledge-sharing session titled CSR Meets the Social Stock Exchange: A Journey Ahead, organised by Equippp Social Impact Technologies Limited (EQUIPPP) and held at Yashoda Hospitals, Hyderabad, recently introduced me to Dr. Bhaskar Chatterjee, a veteran IAS officer, who played a pioneering role in shaping India’s Corporate Social Responsibility framework. The gathering represented a broad cross-section of the social development ecosystem.

Hosted by Dr. Chinnababu Sunkavalli, a robotic cancer surgeon and Founder of the GRACE Cancer Foundation, the programme marked the Foundation’s listing on the Social Stock Exchange. Dr. Chinnababu is also a valued friend, and I have long admired his sustained commitment to making cancer care and early detection accessible to underserved communities. What appeared to be a specialised financial event was, in fact, an important attempt to bring the discipline, transparency and accountability of capital markets into the service of social good.

The Social Stock Exchange addresses a familiar yet persistent problem. Compassion is abundant, but often fragmented. Individuals are willing to contribute, companies have CSR commitments, and social organisations possess valuable field experience. Yet these strengths do not always converge within a credible, transparent and scalable system. Whether donated funds are ultimately deployed for genuine, measurable social good often remains uncertain—an enigma at best and a serious concern at worst.

The term ‘Social Stock Exchange’, or SSE, can initially be confusing. A conventional stock exchange enables companies to raise capital and investors to seek financial returns by buying and selling shares. Are we now proposing to buy and sell charities? “No, no—a thousand times no! Nothing could be further from the truth,” one might say, borrowing the emphatic tone of Sherlock Holmes after eliminating the impossible.

India’s Social Stock Exchange (SSE) is a relatively recent institutional innovation. The Securities and Exchange Board of India (SEBI) formally notified the regulatory framework on 25 July 2022, followed by the issuance of a detailed operational framework on 19 September 2022. The SSEoperates as a separate segment of a recognised stock exchange, enabling eligible social enterprises to register, make prescribed disclosures and raise funds within a regulated framework. Its most distinctive innovation is the Zero Coupon Zero Principal (ZCZP) instrument.

In an ordinary bond, the investor earns interest and expects the principal to be repaid at maturity. A Zero Coupon Zero Principal instrument is fundamentally different: it offers neither interest nor repayment of principal. The contributor provides funds for a clearly defined social purpose, and the ‘return’ lies entirely in the social value created. Yet the instrument is issued within a regulated framework, supported by prescribed disclosures, reporting requirements and accountability. It may therefore be understood as a donation supported by the discipline of the capital market.

Consider a cancer foundation seeking ₹2 crore to operate mobile screening units in underserved districts. Under the traditional model, it may have to approach companies, charitable trusts and individual donors separately, preparing different proposals and complying with different reporting requirements. Funding may arrive irregularly, making it difficult to sustain a programme that depends on specialised equipment, trained personnel, digital data systems, diagnostic referrals and continuous patient follow-up. Such an undertaking requires not only generosity, but also a dependable funding pipeline.

Through the Social Stock Exchange, the foundation can present the programme as a clearly defined project, specifyingthe population to be covered, the personnel and equipment required, the duration, the budget, the referral pathway and the expected outcomes. It can then raise funds by issuing ZCZP instruments for that project. A company may contribute ₹50 lakh, a philanthropic institution ₹25 lakh, and numerous smaller contributors the balance. A mission beyond the capacity of any one donor can thus be supported collectively by many.

The contributors receive neither interest nor repayment, but they gain visibility into how the funds are used, whether the stated targets are achieved, how many suspected cases are identified and referred, and what measurable difference the programme makes. The exchange neither operates the screening units nor guarantees their success. Its role is to provide a transparent and regulated platform that connectsthose who possess resources  with organisations that have the experience and capacity to address social needs.

Corporate Social Responsibility (CSR) enters the picture here. Under Section 135 of the Companies Act, 2013, qualifying companies are required to spend at least two per cent of their average net profits of the preceding three financial years on eligible CSR activities. On 27 May 2026, the Ministry of Corporate Affairs expanded this framework by recognising subscriptions to eligible ZCZP instruments listed on the Social Stock Exchange as permissible CSR expenditure. Companies may use this route for up to ten per cent of their total CSR expenditure in a financial year. The SSE does not replace conventional CSR; it provides an additional regulated channel through which companies can join other contributors in supporting clearly defined social projects.

The value of the SSE lies in four interconnected strengths: trust, visibility, aggregation and accountability. Registration and standardised disclosures establish a common threshold of transparency, allowing a credible social organisation—even one working in a remote district—to reach a much wider community of contributors.

Aggregation can be equally transformative. A public health, education, nutrition or livelihood programme may be beyond the capacity of any single contributor, yet entirely feasible when hundreds or thousands participate. Scattered streams of generosity can thus converge into a river capable of sustaininga major social mission.

Above all, the SSE shifts attention from expenditure to impact. Traditional philanthropy may sometimes measure success by the amount spent, the activities conducted or the number of people reached. The more demanding question is: What actually changed in the lives of the intended beneficiaries?

The central question is not how much money was spent, but what changed as a result. A training programme should be judged by whether participants acquired useful skills and improved their livelihoods. A cancer screening programme should track abnormal findings, referrals, confirmed diagnoses, treatment linkages and, ultimately, lives extended or saved. Data must show not merely that an activity took place, but whether it produced meaningful change. Digital systems and artificial intelligence (AI) can strengthen such accountability at scale.

The SSE should not, however, be romanticised. Listing on the exchange cannot guarantee social transformation. Smaller organisations may struggle with documentation and compliance, and not every valuable outcome can be reduced to a number. Dignity, confidence, solidarity and freedom from fear resist easy measurement. Funding must not therefore flow only to causes whose results are easiest to quantify.

People seek not only wealth, but also meaning. Wealth finds its deepest purpose when it creates a legacy that endures beyond one lifetime. The Social Stock Exchange offers a way to convert generosity into sustained social action by preserving purpose, measuring outcomes and building institutions that endure.

The listing of organisations such as Grace Cancer Foundation is therefore more than a financial milestone. It points to a new social compact in which corporations provide resources, civilsociety organisations contribute field experience, regulators foster trust and citizens participate in measurable public good. The SSE does not put a price on compassion. It gives compassion a platform, a structure and a means of demonstrating what it has achieved.

Grace Cancer Foundation’s dream of deploying 1,000 mobile screening buses across India’s hinterlands can now move closer to reality. Properly channelled, compassion can flow like rain across the countryside, reaching every field rather than only those with their own source of water.

Hats off to these aggregators of compassion. I have encountered few ideas in the social sector that appear so credible, hopeful and potentially transformative. When compassion is aggregated, organised and made accountable, it ceases to be an occasional act of charity and becomes a sustained force for social change.