Tag: science

Some writing advice (mainly physics) for UG students

Some writing advice (mainly physics) I shared with my undergraduate class. This may be useful to others.

  1. Equations, data and figures make meaning when you include a context. This context is expressed using words. Symbols and data by themselves cannot complete the meaning of an argument, unless one knows the context. A common mistake undergraduates make in an exam is to answer questions using only symbols and figures and assume the reader can understand the context.
  2. One way to treat writing in physics (in this case, an exam paper or an assignment) is to imagine you are talking to a fellow physics student who is not part of the course you are writing about. This means you can assume some knowledge, but not the context. Anticipate their questions and address them in the text you are writing. This model also works while writing research papers with some caveats.
  3. While you refer to equations, data and figures in your assignment, make sure you cite the reference at the location of the content you are discussing. Merely listing the references at the end of the document does not make the connection. Remember, while talking, you never do this kind of referencing.
  4. It is useful to structure your arguments with headings, sub-headings and a numbered list. This gives a visual representation of your arguments. You may not find this kind of structured writing in novels, other forms of fictional writing and also in some literature related to social sciences, but in natural sciences with dense information, this will be very useful. Always remember, while writing science (or any form of nonfiction writing), clarity comes before aesthetics.

Also, below is another blog related to written assignments.

Basic advice to undergrads: written assignments

Builders of Modern Scientific India

Images from: Leslie, Stuart W., and Indira Chowdhury. ‘Homi Bhabha Master Builder of Nuclear India’. Physics Today 71, no. 9 (2018): 48–55. https://doi.org/10.1063/PT.3.4021.

When we remember and talk about building modern, scientific India, we must acknowledge past scientists who played a critical role in taking ideas and turning them into reality. Homi Bhabha (image on left) was one of the pioneers. But we must also remember many unknown people of India who literally built modern scientific facilities, such as the CIRUS nuclear reactor (image on right is from 1958). Although their faces are invisible, their contributions should not be.

Physics Nobel – 2025 : Schrödinger’s cat and her laboratory cousins

The 2025 Nobel Prize in physics has been awarded to John Clarke, Michel H. Devoret and John M. Martinis “for the discovery of macroscopic quantum mechanical tunnelling and energy quantisation in an electric circuit.“

The Nobel Prize webpage has an excellent summary of the work at popular and technical levels.

In this blog, I want to draw attention to an interesting review article from 1984 by Anthony Leggett that pre-empts the awarded work. Leggett himself was a Nobel laureate (2003), and his work on the theory of superconductors and superfluids forms one of the conceptual foundations for this year’s Nobel prize. Four of his papers have been cited by the Nobel committee as part of the scientific description of the award, and one of them is a review article I wish to emphasize.

The title of Leggett’s review is “Schrödinger’s cat and her laboratory cousins“. It discusses the detection and implication of macroscopic quantum mechanical entities, and has a description of the so-called Schrödinger’s cat, which is essentially a thought experiment describing quantum superposition and the bizarre consequence of such a formulation. Leggett utilizes this conceptual picture of the cat (in alive and dead states) and extends this to possible scenarios in which the macroscopic quantum superposition can be detected and verified under laboratory conditions. The text below from his review captures the essence of the concept and connects it to experimental verification :

“It is probably true to say that most physicists who are even conscious of the existence of the Cat paradox are inclined to dismiss it somewhat impatiently as a typical philosophers’ problem which no practising scientist need worry about. The reason why such an attitude can be maintained is that close examination of the paradox has seemed to lead to the conclusion that, worrying or not at the metaphysical level, it has at any rate no observable consequences: that is, the experimental consequences of the above apparently bizarre description are quite undetectable. Since physicists, by virtue of their profession, tend to be impatient of questions to which they know a priori no experiment can conceivably be relevant, they have tended to shrug off the paradox and leave the philosophers to worry about it.

Over the last few years, thanks to rapid advances in cryogenics, noise control and microfabrication technologies, it has become clear that the above conclusion may be over-optimistic (or pessimistic, depending on one’s point of view!). To be sure, it is unlikely that in the foreseeable future we will be able to exhibit the experimental consequences of a cat being in a linear superposition of states corresponding to life and death. However, at a more modest level it is possible to ask whether it would be possible to exhibit any macroscopic object in a superposition of states which by a reasonable common-sense criterion could be called macroscopically different. The answer which seems to be emerging is that it is almost certainly possible to obtain circumstantial evidence of such a state of affairs, and not out of the question that one might be able to set up a more spectacular, direct demonstration. This is the subject of this article.“

Cut to 2025, this is also the subject of the Nobel Prize in Physics today.

This year’s laureates, John Clarke, Michel H. Devoret and John M. Martinis, experimentally revealed the quantum mechanics of a macroscopic variable in the form of a phase difference of a Josephson Junction. They called their system a “macroscopic nucleus with wires.”

Quantum Physics Zindabad.

Meghnad Saha – lest we forget

Meghnad Saha (6 October 1893 – 16 February 1956), of the fame of Saha’s ionization formula, was born this day. In 1993, a postage stamp in India was released commemorating his birth centenary.

Saha was an astrophysicist with a broad knowledge and appreciation of various branches of physics. One of the earliest English translations (1920) of the papers on relativity by Einstein and Minkowski was written by Meghnad Saha and S.N.Bose.

At the beginning of the book, Mahalanobis introduces the topic with a historical introduction. He begins with a thoughtful discussion on experiments that eventually ruled out the presence of ether, and it sets the stage as follows:

“Lord Kelvin writing in 1893 in hig preface to the English edition of Hertz’s Researches on Electric Waves, says many workers and many thinkers have helped to build up the nineteenth century school of plenum, one ether for light, heat, electricity, magnetism; and the German and English volumes containing Hertz’s electrical papers, given to the world in the last decade of the century, will be a permanent monument of the splendid consummation now realised.”

Ten years later, in 1905, we find Einstein declaring that “the ether will be proved to be superflous”. At first sight the revolution in scientific thought brought about in the course of a single decade appears to be almost too violent. A more careful even though a rapid review of the subject will, however, show how the Theory of Relativity gradually became a historical necessity.

Towards the beginning of the nineteenth century, the luminiferous ether came into prominence as a result of the brilliant successes of the wave theory in the hands of Young and Fresnel. In its stationary aspect, the elastic solid ether was the outcome of the search for a medium in which the light waves may “undulate.” This stationary ether, as shown by Young, also afforded a satisfactory explanation of astronomical aberration. But its very success gave rise to a host of new questions all bearing on the central problem of relative motion of ether and matter.“

Saha, in various capacities, took a stance against British colonialism. Although it affected some opportunities, he continued to do science and was recognized for his outstanding contributions. As Rajesh Kochhar mentions:

“Saha had wanted to join the government service, but was refused permission because of his pronounced anti-British stance. For the same reason, the British government would have liked The Royal Society to exclude Saha. It goes to the credit of the Society that it ignored the pressures and the hints, and elected him a fellow, in 1927. This recognition brought him an annual research grant of £300 from the Indian government followed by the Royal Society’s grant of £250 in 1929 (DeVorkin 1994, p. 164).“

Saha led a tough life. He not only had to face suppressive British colonial rule but also academic politics and battles (versus Raman, no less). His knowledge of physics, his contributions to Indian science, and his commitment to people (he was a politician too) were significant. Let me end the blog with a few lines from Arnab Rai Choudhuri’s article, which nicely summarizes Saha’s work (specifically his ionization formula), and his scientific life:

“Saha’s tale of extraordinary scientific achievements is simultaneously a tale of triumph and defeat, a tale both uplifting and tragic. Saha showed what a man coming from a humble background in an impoverished colony far from the active centres of science could achieve by the sheer intellectual power of his mind. But his inability to follow the trail which he himself had blazed makes it clear that there are limits to what even an exceptionally brilliant person could achieve in science under very adverse circumstances.“

India and Indian science should remember Meghnad Saha.

Conversation with Aparna Deshpande

Welcome to the podcast, Pratidhavani – Humanizing Science

Aparna Deshpande is an Associate Professor of Physics at IISER Pune, specializing in atomic-scale exploration of two-dimensional materials and their interfaces using scanning tunneling microscopy. She is deeply engaged in research on nanomaterials and is active in physics education (as part of the department of science education at IISER Pune), communication, and outreach at IISER Pune.

Aparna is also the faculty in charge of the Smt. Indrani Balan Science Activity Centre at IISER Pune, where she leads diverse science outreach and STEM education initiatives, promoting hands-on multi-lingual learning and innovative workshops for students and teachers across India.

In this conversation, we explore her research in physics and science education.

You can also watch or listen on spotify

References:

[1] “Dr. Aparna Deshpande.” Accessed: Sept. 25, 2025. [Online]. Available: https://draparnadeshpande.github.io/portfolio/

[2] “Dr. Aparna Deshpande (@DrAparnaIISERP) / X.” X (formerly Twitter). Accessed: Sept. 25, 2025. [Online]. Available: https://x.com/draparnaiiserp

[3] “Aparna Deshpande | LinkedIn.” Accessed: Sept. 25, 2025. [Online]. Available: https://www.linkedin.com/in/aparna-deshpande-01927015/?originalSubdomain=in

[4] “Aparna Ramchandra Deshpande – Google Scholar.” Accessed: Sept. 25, 2025. [Online]. Available: https://scholar.google.com/citations?user=f5FnqMIAAAAJ&hl=en

[5] “Aparna Deshpande – IISER Pune.” Accessed: Sept. 25, 2025. [Online]. Available: https://www.iiserpune.ac.in/research/department/physics/people/faculty/regular-faculty/aparna-deshpande/259

[6] J. Poskett, Horizons. London, UK: Penguin Books, 2023. Accessed: Sept. 25, 2025. [Online]. Available: https://www.penguin.co.uk/books/313423/horizons-by-poskett-james/9780241986264

[7] P. Lockhart and K. Devlin, A Mathematician’s Lament. Illustrated ed. New York, NY: Bellevue Literary Press, 2009. https://www.blpress.org/books/a-mathematicians-lament/

Satish Dhawan – truly a man for all seasons

Image credit: Current Science 119, no. 9 (2020): 1427–32

Today is the birth anniversary of Satish Dhawan (25 September 1920 – 3 January 2002). He was probably India’s best scientist-administrator who headed institutions such as the Indian Institute of Science and the Indian Space Research Organization. With a PhD from Caltech, he came back to India and set up a marvellous research enterprise on fluid mechanics, including aerospace science and engineering. He mentored some of the outstanding scientists of India and led scientific institutions with vision, openness and informality, which is still a great benchmark to emulate1.

Below are a couple of historical documents related to Dhawan:

The first one is a lecture note from 1979, on making a case for a national satellite system and how it influences science and scientific activity (a copy of this note has been reproduced in a wonderful tribute to Satish Dhawan written by P. Balaram on his birth centenary2).

The next one is a beautiful perspective article written by Dhawan on ‘Bird Flight’ from an aerodynamics perspective3. It is a detailed overview of the dynamics of bird flight and shows Dhawan’s interest and ability to bridge two facets of science. It is a prototypical example of interdisciplinary research.

Finally, let me end the blog with a quote from P. Balaram on Satish Dhawan4:

“Dhawan mentored some remarkable students and built the discipline of aeronautical engineering at the Institute. He influenced aeronautical research and industry in India in a major way. He shepherded the Indian space programme following Vikram Sarabhai’s untimely death. He served the Indian scientific community in many ways. His stewardship transformed IISc. How then do we describe such a man? Dhawan studied English literature obtaining a Master’s degree in his youth. It may therefore be appropriate for me to borrow a 16th century description of Sir Thomas More:


‘[Sir Thomas] More is a man of an angel’s wit and
singular learning. I know not his fellow. For where is
the man of that gentleness, lowliness and affability?
And, as time requireth, a man of marvelous mirth and
pastimes, and sometime of as sad gravity. A man for
all seasons.’

Satish Dhawan was truly a man for all seasons.”

Happy Birthday to Prof. Satish Dhawan!

References:

  1. Current Science, in 2020, had a section of a volume dedicated to the birth centenary of Satish Dhawan, and has a foreword by his daughter and articles by many of his students and co-workers. https://www.jstor.org/stable/e27139029 ↩︎
  2. P. Balaram, “Satish Dhawan: The Transformation of the Indian Institute of Science, Bangalore,” Current Science 119, no. 9 (2020): 1427–32. This reference has many interesting references, including a handwritten obituary of CV Raman written by Dhawan https://www.jstor.org/stable/27139041. ↩︎
  3. S. Dhawan, “Bird Flight,” Sadhana 16, no. 4 (1991): 275–352, https://doi.org/10.1007/BF02745345. ↩︎
  4. P. Balaram, Current Science 119, no. 9 (2020), page 1432. https://www.jstor.org/stable/27139041. ↩︎

Sir MV on Education

In India, “National Engineers’ Day is celebrated every year on September 15 to honor the birth anniversary of Sir Mokshagundam Visvesvaraya, one of India’s greatest engineers”. Sir MV, as he was known, is one of the 20th-century Indians I admire. He was a forward-looking statesman who contributed immensely to building India (literally and figuratively). MV was a well-read and well-travelled person for his era, and wrote a few books and memos that are still pertinent to the current developments in India and the world.

Reconstructing India (1920)

One of his books, Reconstructing India (1920), reveals his thoughts on how and why India needs to reconstruct itself based on knowledge in science, technology and humanities. The title page is shown below, and the book is free to read online, thanks to the Internet Archive.

The book, as mentioned by MV in the preface, was written just after the First World War, and contemplates problems faced by India in light of geopolitical developments. In the 17 chapters of the book, divided into 4 parts, MV discusses specific issues faced by India, and proposes that political and administrative reforms can help India become a progressive society.

The largest part of the book is on economic reconstruction, in which he proposes contemporary methods (for the 1920s) to improve various sectors of manufacturing, including agricultural technology and communication media.

The third part of the book is on social reforms, and in there, he has a dedicated chapter on Education, which caught my attention, and I found it relevant even for today’s India.

Education, Humanities, and STEM

It is important that students of science and technology have a good exposure to some aspects of the humanities, including economics, history and philosophy. The pursuit and ability to choose good problems in science and technology critically depend on the social and economic structure in which they are practiced in universities and research institutions. MV anticipated this and highlights it as:

“Secondary and university education, though producing many able recruits for subordinate positions in the Civil Service, does not provide the men needed to carry on the work of agriculture, engineering, commerce and technology. The provision for training in economics and history is inadequate, and the study of those subjects is even discouraged. An attempt is actually made to teach economics in such a way as to render India’s emergence from a state of dependency difficult.”

Even in 2025, I would suggest that STEM students pay attention to economics, as it anchors them to understand the need and functions of a society, and therefore, their work can be calibrated accordingly. This is not to discourage open-ended research, but to understand how natural sciences are connected to the societal thoughts and needs. It gives us a broader understanding of the context, which is so important while understanding the evolution of ideas.

Comparative Education Systems

There is always a lot to learn from various societies and cultures. In order to do so, one needs comparative analysis. This helps one to choose some good elements from a society that can be emulated elsewhere. MV compares and comments on the 1900s British educational system in contrast to the German and Japanese counterparts. Note that India in the 1920s was still a British colony, and in a way, MV is critical of the system in which he himself was educated and trained. As he notes:

“Britain herself has had to pay a heavy price for her hand-to-mouth policy in regard to education. The educational chaos still existing there compares unfavourably with the great yet orderly progress made by Germany and Japan, both of which countries, after weighing and testing the educational systems of the world, absorbed the best of all.”

These were words written long before the Second World War, and give us a glimpse of how German and Japanese systems were functioning in the 1920s and had a lot to offer to the world. Of course, history took its own path, and German and Japanese society had other ideas.

Incidentally, I am writing this piece sitting in Leipzig (eastern Germany), and I am amazed by its architectural marvels that date back centuries. Indeed, German society had (and has) a lot to offer to the world. As MV indicates above, we need to absorb the best that is on offer. In doing so, we also need to reject that which is not good for any society.

Liberal Education and Financial Support

He further adds how liberal education adds value to a society, and calls not only the government but also the people to recognize the importance of financial support for education.

“Both the Government and the people must recognize that only by pursuing a liberal educational policy, and making generous financial provision for schools and colleges can they lift India out of her present low condition and ensure rapid progress.”

These words still hold good, and as a society, India has to re-emphasize modern education that helps us become not only better doctors and engineers, but also better human characters that can add value to the “modern” world.

Call to Action

In the final part of the book, MV makes a passionate appeal to the people of India, calling them to take action and move towards becoming a progressive nation:

“Do the people of India propose to profit by the lessons which world experience has to teach them, or will they be content to allow matters to drift and themselves grow weaker and poorer year by year?
This is the problem of the hour. They have to choose whether they will be educated or remain ignorant; whether they will come into closer touch with the outer world and become responsive to its influences, or remain secluded and indifferent; whether they will be organized or disunited, bold or timid, enterprising or passive ; an industrial or an agricultural nation ; rich or poor ; strong and respected, or weak and dominated by forward nations. The future is in their own hands.”

Indeed, the future is in our hands, and these words written more than 100 years ago still resonate loudly. We need more engineers like Sir MV. The reason he was so effective was that he combined thinking and doing. Importantly, the lesson we can learn from MV’s life and by reading this book, is that an open mind can grasp good ideas at any time and anywhere. Implementing those ideas is an equally important challenge, and MV was up to this in his own way. Are we, as Indians, open to this prospect and engineer our future?

Gardner’s Synthesis

Once in a while, during my research, I come across writing by scholars from other disciplines that gives me a perspective that not only helps me to grasp the complexity of learning across disciplines, but also resonates with some thoughts on education.

Howard Gardner is one such academic who works on developmental psychology and has researched extensively on cognition and education. He has written ~30 books and ~1000 articles, and blogs regularly, even at the age of 82 or so. His recent book is titled A Synthesizing Mind.

Howard Gardner is a renowned Harvard academic and, as his book describes him as follows:

“Throughout his career, Gardner has focused on human minds in general, or on the minds of particular creators and leaders. Reflecting now on his own mind, he concludes that his is a ‘synthesizing mind’—with the ability to survey experiences and data across a wide range of disciplines and perspectives. The thinkers he most admires—including historian Richard Hofstadter, biologist Charles Darwin, and literary critic Edmund Wilson—are exemplary synthesizers. Gardner contends that the synthesizing mind is particularly valuable at this time and proposes ways to cultivate a possibly unique human capacity.”

While exploring the book and the related material, I came across an interview with Howard Gardner. In there, he is conversing about the theme of the book and discusses the synthesis of thought across disciplines. One of the pertinent aspects of learning is to know how innovation can be fostered by cross-disciplinary exploration without diluting disciplinary rigour. As Gardner says:

“I am not opposed to disciplinary learning—indeed I am an enthusiastic advocate. Any person would be a fool to try to create physics or psychology or political science from the start. But if we want to have scholars or professionals who are innovative, creative—and innovation is not something that we can afford to marginalize—then they cannot and should not be slaves of any single discipline or methodology.”

As a physicist, I can relate to this thinking within my discipline, and how innovative ideas, over the ages, have emerged by bringing ideas from mathematics, engineering and biology into physics. Particularly, the combination of biology, physics and mathematics is one of the most exciting frontiers of human exploration today, and Gardner’s words apply well in this scenario.

Going beyond science, I am always intrigued and amazed by artists (especially musicians) who can create art that simultaneously draws the attention of specialists and generalists. This is not a trivial achievement, and as a scientist, I am always trying to understand how artists resonate so well with the public. Gardner, in the abovementioned interview, frames this problem by looking at the goals of science and arts, and draws a contrast that is worth noting:

“Most scholars and observers like to emphasize the similarities between the arts and the sciences, and that is fine. But the goals of the two enterprises are different. Science seeks an accurate and well supported description of the world. The arts seek to capture and convey various aspects of experience; and they have no obligation other than to capture the interest and attention of those who participate in them.

Of course, there are some individuals who excel in both science and art (Leonardo is everyone’s favorite example). But most artists—great or not—would not know their way around a scientific laboratory. And most scientists—even if they like to play the violin or to draw caricatures or to dance the tango—would not make works of art or performances that would interest others.”

I partially agree with this assessment, as I know a few scientists who are deeply involved in various forms of art (including music) and do it very well, even at the professional level. In a way, Gardner is re-emphasizing the “two cultures” debate of C.P. Snow. My own thoughts on this viewpoint are ambivalent, as I see science, arts and sports as important pursuits that cater to different facets of the human mind. Of course, when it comes to expertise, the division may matter. There is a lot more to learn about the interface of art and science, at least for me.

Anyway, Gardner is a fabulous writer, and his blogs and books are worth reading (and studying) if one is seriously interested in understanding how to synthesize thought across disciplines.

Since we are discussing synthesis of thought, which is a kind of harmony, and coming together, let me end the blog with a line from Mankuthimmana Kagga by the Kannada poet-philosopher D.V. Gundappa:

“ಎಲ್ಲರೊಳಗೊಂದಾಗು ಮಂಕುತಿಮ್ಮ” (Eladaralongodhagu manku thimma)

which loosely translates to: oh fool…be one among all (blend into world, living in harmony).

Harmony of disciplines and minds – how badly the world needs it today?

When Chandra wrote to Hawking

Learning is a lifelong process, and even the best researchers have to update their knowledge as and when they come across new information. Subrahmanyan Chandrasekhar was undoubtedly one of the most accomplished mathematical astrophysicists in the 20th century, and his range of topics covered almost all aspects of astrophysics.  Chandra (as he was known) was a lifelong learner, and took up new topics within astrophysics, researched them deeply, and wrote definitive books on them, which are still of great utility even today. In his research process, Chandra consulted various scholars across the world, irrespective of their age, and learned new things.

In 1967, Chandra, aged 57, wrote a letter to a 25-year-old researcher, Stephan Hawking, to learn more about his work ‘on the occurrence of singularities in cosmology’. In this letter, which is written in a desperate tone, Chandra mentions that he is grappling with some mathematical aspects of Stephen Hawking’s work and is asking him for references that he can consult to understand his papers. Chandra describes reading Hawking’s papers as  ‘climbing a staircase moving downwards’. Below, I reproduce the letter (from the University of Chicago archives).

 To this letter, Hawking dutifully replies (see below), suggesting specific books on topology and differential geometry. Hawking also suggests some of his published papers. Hawking himself downplays his knowledge of mathematical aspects related to the work, and mentions that it improved after he consulted the mentioned books. Below, I reproduce the handwritten letter (from the University of Chicago archives).

There are two aspects that are interesting to note:  one is the fact that even accomplished researchers have to learn and relearn many things as they get exposed to new information, which calls for humility and setting aside egos, and the second aspect is that ideas are built on existing ideas available at that time, and a major part of it is to learn from papers, books and of course communicating with people, as Chandra did in this case.

Science, after all, is a human endeavor.

Some Optical and IR observatories in India

Below are ‘locations of some of the optical and infrared observatories marked on the Indian map’.

from: Narendranath, Shyama, Shashikiran Ganesh, Dipen Sahu, et al. 2025. “Solar System Research Prospects for the Decade and Beyond.” Journal of Astrophysics and Astronomy 46 (2): 34. https://doi.org/10.1007/s12036-025-10060-0.