• Ashoke Sen’s extraordinary scientific journey reminds us that the greatest discoveries begin not with certainty, but with the courage to ask questions that no one has yet answered.

Professor Ashoke Sen is a name I first encountered many years ago, perhaps in the pages of a children science magazine . The memory is faint, but the name has remained with me, like the recollection of an unfamiliar door opening briefly upon a world of extraordinary ideas. His recent receipt of the Oskar Klein Medal has brought him renewed public attention, and with it a wave of justifiable pride. As the first Indian physicist to receive this distinction, he has given us ample reason to celebrate; some have even begun to wonder whether a Nobel Prize might one day follow. I sincerely hope it does. Yet, amid the applause and the accolades, I find myself drawn to a more intriguing question: what is it, precisely, that this remarkable physicist has spent his life trying to understand? For behind every great scientific achievement lies something more compelling than a medal—the restless curiosity of a mind unwilling to accept the universe merely as it appears, and daring enough to ask what might lie beneath its bewildering surface.

There is, of course, nothing unusual about our pride when someone from Bengal receives international recognition. Cultural kinship has a way of making another person's achievement feel almost personal. Yet there is a difference between celebrating a scientist and understanding the significance of his work. Perhaps the more meaningful tribute is to look beyond the award and explore the questions that have occupied his mind. Let me, therefore, attempt to explain, in language as simple as I can manage, something of the extraordinary intellectual adventure to which Ashoke Sen has devoted his life.

The universe has a secret. Could it be one secret, rather than many?

We encounter the world as an astonishing variety of things. Stars burn in distant galaxies; planets circle their suns; electricity illuminates our homes; atoms combine to form the matter from which our bodies are made. Beneath this bewildering diversity, however, modern physics has identified four fundamental forces: gravity, electromagnetism, the strong nuclear force and the weak nuclear force.

Gravity holds us to the Earth and governs the movements of planets and stars. Electromagnetism underlies light, electricity and much of the chemistry of everyday life. The strong and weak nuclear forces operate within the subatomic world, helping to determine the behaviour of matter at its most fundamental levels.

To our ordinary senses, these forces appear distinct, each obeying its own rules. Yet one of the most ambitious dreams in the history of physics has been to discover whether this apparent multiplicity conceals a deeper unity.

Physicists have already shown that electromagnetism and the weak nuclear force can be understood within a unified theoretical framework. But a complete, experimentally verified theory, encompassing gravity and the other fundamental forces. remains elusive. The search continues for a more comprehensive account of nature, one that might explain why the universe possesses the structure it does.

Imagine discovering that thousands of different melodies could be produced from a single underlying musical language. The melodies would remain distinct, yet their apparent diversity would rest upon a common foundation.

Could nature possess a comparable unity?  Among the most ambitious attempts to explore this possibility is string theory.

What if the universe were made of music?

Imagine examining a grain of sand, a leaf or your own hand through a microscope of unimaginable power. Move beyond the familiar world of molecules and atoms, towards the elementary constituents of matter. 

Now imagine that, at the deepest level described by string theory, the fundamental objects are not mathematical points but extraordinarily tiny, vibrating strings.

Different patterns of vibration would correspond to different particles, much as different vibrations of a violin string produce different musical notes. The analogy is imperfect, but it offers an accessible glimpse of the theory's central ambition: apparently different constituents of reality might emerge from different manifestations of a common underlying structure. The bewildering variety of matter and forces might be understood through a more fundamental mathematical framework. 

It is an extraordinary possibility. But a crucial qualification is necessary: string theory has not yet been experimentally confirmed as a description of nature. Its mathematical sophistication and theoretical appeal do not establish that the universe is actually made of strings.

Science cannot rest upon elegance alone. Ultimately, a theory must confront evidence.Yet the absence of experimental confirmation does not make the intellectual endeavour meaningless. It makes the distinction between possibility and proof all the more important. The history of science is a reminder that the pursuit of understanding often begins long before the necessary instruments, observations or experimental techniques become available.

The question, then, is not simply whether string theory will prove correct. It is also what its investigation has taught us about the mathematical structures through which we attempt to understand the universe. This is where Ashoke Sen enters the story.

Ashoke Sen: the detective of hidden connections

Professor Ashoke Sen has made major contributions to string theory, including the study of duality—the discovery that apparently different theoretical descriptions can, under certain conditions, be related to one another or describe the same underlying physics.

Consider two maps of the same city. One displays the roads; another shows the railway network. They appear to represent different systems. Yet a closer examination may reveal connections that help us understand the city as a whole.

In theoretical physics, such relationships can be far more subtle. Two mathematical frameworks that initially seem unrelated may turn out to possess a deep correspondence. Establishing that relationship can transform the way scientists approach a problem.

Sen's work has helped reveal and clarify important connections of this kind, advancing our understanding of string theory and its implications for fundamental physics.

One particularly significant area of his research concerns black holes.Black holes are among the most astonishing objects in the universe. According to Einstein's general theory of relativity, gravity can become so intense that, beyond a boundary known as the event horizon, nothing can escape—not even light.

But black holes pose questions that extend far beyond their dramatic image. They challenge physicists to reconcile gravity with quantum mechanics and to understand how information behaves under extreme conditions.

One important concept is entropy, which, in this context, is related to the number of microscopic 

configurations compatible with a black hole's observable properties. Explaining black-hole entropy from a microscopic perspective has become a central problem in theoretical physics.

Sen's work has contributed to this field, including research into black-hole entropy and the mathematical structures that allow certain properties of black holes to be investigated within string theory.

The significance of such work lies in the connections it establishes between different areas of physics. Calculations developed through string-theoretic methods can, in appropriate settings, reproduce results associated with black-hole physics. These correspondences offer valuable insights into the internal consistency and explanatory possibilities of theoretical frameworks that might otherwise appear disconnected.

They do not prove that string theory is the final description of nature. They demonstrate something more precise: that seemingly different approaches can contain unexpected mathematical coherence, and that this coherence can open new avenues of investigation.

Scientific greatness does not always consist of announcing a discovery that the world can immediately see. Sometimes it means solving a problem that has resisted years of effort, finding a connection no one previously recognised, or showing that two apparently incompatible ideas may be understood within a common framework.

Such achievements may not produce a spectacular photograph or an instantly marketable invention. Yet they can change the intellectual landscape in which future discoveries become possible.

Why should young people care?

Because the most exciting thing about science is not what we already know. It is what we have yet to discover.

Young people are frequently encouraged to think of education as a race: secure the marks, obtain the qualification, find the job and move ahead. There is nothing wrong with ambition or professional success. But education becomes impoverished when it leaves no room for wonder.

Science begins somewhere else. It begins when someone looks at the night sky and asks why the stars shine. When a student wonders whether a familiar explanation is incomplete. When a seemingly simple question refuses to go away, even after everyone else has moved on.

The scientist's essential equipment is not merely a laboratory, a computer or an expensive instrument. It is a mind capable of questioning assumptions, testing explanations and remaining patient when the answers do not arrive.

That is why Ashoke Sen's story matters to young people who may never become physicists. His career illustrates the possibilities of sustained intellectual curiosity. It shows that one can devote a lifetime to problems whose solutions are neither immediate nor guaranteed, and that difficult, highly specialised work can contribute to humanity's collective understanding.

It also offers a lesson about uncertainty. Science is not a procession of unquestionable certainties. It is a continuing conversation between ideas, mathematics, observation and evidence. A theory may be elegant and still be wrong. An accepted explanation may need revision. An unanswered question may eventually open an entirely new field of investigation.

For young minds, there is something liberating about this. You do not have to know everything before you begin asking questions. You do not even have to be certain that your first idea is correct. You must be willing to investigate, to learn, to revise and to try again.The courage to be wrong, provided one is prepared to learn from the mistake, is an essential part of intellectual progress.

Perhaps this is one of the most valuable lessons a scientist can offer a generation growing up in a world saturated with instant answers, confident opinions and information that is not always reliable. The ability to distinguish evidence from assertion, knowledge from speculation and curiosity from credulity is not merely useful in science. It is indispensable to an informed citizen.

Beyond celebrity: celebrating the life of the mind

Our public culture has ample room for film stars, sporting heroes and political personalities. Their 

achievements and failures are discussed endlessly, often with an intensity that more enduring questions rarely receive.

Scientists, by contrast, frequently enter public conversation only when they win a prestigious award or when a controversy briefly makes their work newsworthy.

We should do better.

Imagine a school corridor displaying not merely photographs of famous personalities but also portraits of scientists, accompanied by short, engaging accounts of the questions they pursued. Imagine children learning how a mathematician solved a difficult problem, how an astronomer inferred the existence of something invisible, or how a physicist spent years investigating the nature of a black hole.

The purpose would not be to turn scientists into idols. It would be to make intellectual achievement visible and curiosity respectable.

Bengal possesses a distinguished scientific and intellectual heritage. But heritage is not a substitute for creating the conditions in which the next generation can flourish. Young people need good teachers, accessible books, functioning laboratories, encouragement to question authority and the freedom to explore ideas beyond the immediate demands of examinations.

They also need to understand that scientific merit must be judged by the quality of the work, not by a person's political loyalties or public disagreements. A scientist's criticism of a government neither invalidates his research nor exempts it from scrutiny. Evidence, not allegiance, must remain the standard.

Professor Ashoke Sen belongs to a tradition of inquiry whose significance extends far beyond Bengal or India. His work forms part of humanity's shared effort to understand the universe. That is a source of pride worth cultivating—not merely pride in the medal, but pride in the intellectual journey behind it.

The next great question may be waiting in a classroom

There is, of course, no guarantee that string theory will ultimately provide the unified account of nature that its proponents seek. Its relationship with experiment remains one of the central challenges facing the field.

Nor should we assume that every ambitious scientific idea will succeed. The history of science is filled with hypotheses that did not survive scrutiny, alongside discoveries that transformed our understanding in ways their originators could scarcely have imagined.

That is precisely why the process matters.

We should tell young people about Ashoke Sen not because they must follow his path, but because they should know that such paths exist. We should tell them about the problems he has investigated, the mathematical ingenuity his work has demanded and the patience required to pursue questions without immediate answers.

We should tell them that a life devoted to understanding can be as adventurous as one devoted to exploration, and that the frontiers of human knowledge are not always geographical. Some lie in equations, in laboratories, in the depths of space—and in questions that have not yet found their answers.

Perhaps somewhere in Bengal, a student is sitting at the back of a classroom, bored by a lesson that seems to have little connection with the world outside. Perhaps that student will one day encounter the idea that the universe may possess a hidden mathematical order. A question will take root. A book will be opened. One question will lead to another.

No one can predict what will follow.

But perhaps that student will become a physicist. Perhaps a mathematician, an engineer, a philosopher—or something we do not yet have a name for.

The point is not that every child must become another Ashoke Sen. It is that no child should be denied the opportunity to discover what an inquisitive mind can accomplish. So let us celebrate the medal, certainly. Let us take pride in the scientist. But, above all, let us celebrate the question that has not yet been answered.

(A well-recognised Delhi-based author and commentator, is a regular TEW columnist on politics, culture, and sports.)