Category: general

59. Who is a physicist?

“The physicist is most cogently identified, not by the subject studied, but by the way in which a subject is studied and by the nature of the information being sought.”

Above is an interesting quote by Sol Gruner, James Langer, Phil Nelson, and Viola Vogel from a 1995 article in Physics Today titled WHAT FUTURE WILL WE CHOOSE FOR PHYSICS?

Although written more than 25 years ago from the viewpoint of US physics community, many of the issues discussed in this article are pertinent even today. Probably more so in the Indian context.

Nice read :

What Future Will We Choose for Physics?
Sol M. Gruner, James S. Langer, Phil Nelson, and Viola Vogel
Citation: Physics Today 48, 12, 25 (1995); doi: 10.1063/1.881477
View online: https://doi.org/10.1063/1.881477

55. Kindness in science

There is absolutely no conflict between doing good science and being kind to people with whom you work, and this includes not only colleagues and students, but also administrative staff and everyone in an academic ecosystem. The below linked article makes a good case for this point.

It also derives some relevant lessons from philosophy which can be applied to academic environment. Worth reading…if you have access

https://www.cell.com/trends/cell-biology/fulltext/S0962-8924(21)00229-4

54. End-sem email to my class

Below is an email I sent to my introductory-optics class of 77 students (third-year undergraduates) on the final day of my course, which was today. Although the course was completely online, I did enjoy interacting and discussing with them on various topics on optics and photonics.

———————

Dear All,


Today is the final day of the optics course – PH3134, and I hope all of you have gained some knowledge from the online interaction we had over the past months. 


Optics is one of the most fascinating areas of science, and historically one of the oldest topics in physics. Yet, it continues to throw new surprises in contemporary research. I hope some of you will pursue research in optics and related areas. Even otherwise, do remember that optics plays a vital role in understanding and implementing various aspects of science and technology. Its relevance has remained high for centuries, and will remain so for the foreseeable future. 

I know many of you are at home, and conditions are not ideal for studies. So, thank you for keeping up your interests even during these tough times. I highly appreciate it.


An important take away for me as a teacher/researcher (from every course I teach) is that what we have discussed and studied is just a metaphoric drop in a mighty ocean of knowledge. That means there is a lot to learn for all of us. Do keep learning beyond the coursework. There is no limit for that.


Light up the world !

best wishes,

Pavan

53. Karnad’s preface to his memoir

One of the important aspects of reading a preface to a book is to know why an author wrote that book. This is one place where authors freely express their opinion on various things, and sometimes this opinion is not necessarily related to that book. For me, reading the preface connects me to the author in a better way than say, reading a review of the book, which I generally do after reading the book. Over the years, I have made it a habit to read the preface of almost any book I have come across.
In this context, recently I came across one of the most hilarious prefaces I have read. This is from Girish Karnard‘s memoir (translated from Kannada) titled : this life at play.


Below I reproduce the preface (which is by the way, available online) :

Dharwad, 1973

Aayi (my mother), Bappa (my father) and I were having lunch. My first film Samskara had won the President’s Gold Medal. My second, Vamsha Vriksha, had had a successful run and won the National Award for best direction. My latest film Kaadu was in the final stages of production. I was a Sangeet Natak Akademi awardee. And I had just been named the director of the Film and Television Institute of India. The air at home was thick with self-congratulation.

Then Aayi looked at Bappa and said, ‘And we had thought of not having him.’Bappa went red in the face. After some stammering, he managed to say, ‘That was all your idea, not mine. Why bring this up now?’ and hid his face in the plate in front of him.

I had to know more. I asked Aayi, and she explained: ‘I had three children already when I became pregnant with you. I thought that was enough, so we went to a doctor in Poona named Madhumalati Gune.’

‘And?’

‘She had said she would be at the clinic, but she wasn’t. We waited an hour and returned.’

‘And then?’

‘And then, nothing. We never went back.’

I was stunned. I was then thirty-five years old. Still, I grew faint at the possibility that the world could have gone on without me in it. For a while, I sat there unaware of my surroundings, considering the idea of my non-existence. A thought struck me. With some bewilderment, I asked about my younger sister: ‘Then, what about Leena…?’

Aayi said, somewhat coyly, ‘Oh, we had stopped thinking of all that by then.’ She burst out laughing. Bappa remained engrossed in the contents of his plate.

Had the doctor arrived at the clinic as promised, these memoirs and their narrator would not have existed. So, I dedicate this autobiography to the memory of the person who made all this possible: Dr Madhumalati Gune.

Girish Karnad

Bangalore, 19 May 2011

47. Nagendra, Weinberg and some memories…

IIA days…

It was late summer/early monsoon season of 2003, in Bangalore. The BTS bus travel from Rajajinagar to Koramangala via Majestic used to take 90 min or more. This commute, which I did for about 2 to 3 months, as summer student at Indian Institute Astrophysics (IIA) is still etched in my memory. I had just finished my first year MSc (Physics), and was seriously hooked on to physics in general, and astrophysics in particular. My summer project was on second solar spectrum guided by Prof. K. N. Nagendra (KNN) at IIA. It was he who introduced me to the fabulous world of polarization optics in the context of solar physics. This opened my eyes to the spectacular world of photon transport through an inhomogeneous medium, and hence multiple scattering of light. It was KNN who also introduced me to the classic : Radiative Transfer by Subrahmanyan Chandrasekhar. My first task as a summer student was to read the first chapter of this book and understand the representation of polarized light using Stokes parameters. The summer of 2003, was also the first time I encountered the power of computational methods to solve scientific problems, and ever since then I have deeply appreciated the role of computers in solving scientific problems. This introduction to computational physics and polarization optics (in the form of Jones, Stokes and Muller matrices) has turned out to be an important concept which I still use in my research. I thank KNN for this.

Recently, I was shocked to know that Prof. KNN passed away. His death was untimely, and a very sad news to me and many of the people who knew him. My condolences to his family, friends and students.

Weinberg inspires…

Recently, I also came to know about the sad demise of Steven Weinberg. Thanks to a special paper on Introduction to Quantum Electrodynamics in the final semester of my MSc, I learnt a bit about Weinberg as we were introduced to some aspects of unification of weak and electromagnetic forces. Also, with great enthusiasm, I learnt a lot from his fascinating book : The First Three Minutes: A Modern View of the Origin of the Universe. Undoubtedly, the scientific world has lost a great thinker.

The greatest impact of Weinberg on me was in a different context. In summer of 2004, I was selected for a PhD position at JNCASR. Prof. Chandrabhas had agreed to take me in as a PhD student, and I was elated and excited to join his group. I still remember the first time I visited his lab (after the selection) sometime in late May or early June 2004. As I entered the lab and opened that famous sliding door, there was a print-out of an article which was pasted right beside the door. This article was the Four Golden Lessons by Steven Weinberg, which was then recently published in 2003. This was literally, the first article I read as a PhD student in the lab, and has deeply impacted my work.

I still revisit the four golden lessons, time and again, and has been extremely useful throughout my career. As a tribute to him, below I reproduce the third lesson, which I think is worth contemplating :

My third piece of advice is probably the hardest to take. It is to forgive yourself for wasting time. Students are only asked to solve problems that their professors (unless unusually cruel) know to be solvable. In addition, it doesn’t matter if the problems are scientifically important — they have to be solved to pass the course. But in the real world, it’s very hard to know which problems are important, and you never know whether at a given moment in history a problem is solvable. At the beginning of the twentieth century, several leading physicists, including Lorentz and Abraham, were trying to work out a theory of the electron. This was partly in order to understand why all attempts to detect effects of Earth’s motion through the ether had failed. We now know that they were working on the wrong problem. At that time, no one could have developed a successful theory of the electron, because quantum mechanics had not yet been discovered. It took the genius of Albert Einstein in 1905 to realize that the right problem on which to work was the effect of motion on measurements of space and time. This led him to the special theory of relativity. As you will never be sure which are the right problems to work on, most of the time that you spend in the laboratory or at your desk will be wasted. If you want to be creative, then you will have to get used to spending most of your time not being creative, to being becalmed on the ocean of scientific knowledge. (emphasis is mine)

Thank you, KNN and Weinberg…for some golden lessons…

45. Scientific Gandhism

Thanks to Gautam Menon, I came across this article in Nature, which makes an interesting case for being self critical of one’s own published work.

Perhaps, this is a good way to go, although much easier said than done. Overall, I strongly support the line of thinking of looking inward and being critical of one’s work.

One of the motivations for writing my blog is to highlight the human element of doing science, and honest mistakes in the pursuit of science are very much part of it.

This is indeed a good culture to inculcate and encourage in a day and age where everything negative and critical is looked down upon as a disadvantage.

The article also reminds me of Peter Medawar’s talk: “Is the scientific paper a fraud?” , which was one of the most refreshing viewpoints on the pursuit of science that I have read. Interestingly, there has been quite a lot of debate on this question, and is worth exploring.

Also there is an element of Gandhism in being truthful to oneself and others, which is refreshing to see in scientific world :-)

43. Gadagkar’s article

Central to scientific thinking is the ability to create an idea, test it rigorously, and report the results. This thinking is made coherent and expressed in the form of writing. Scientific research indeed can be fostered and improved by writing well, especially when guided by the goals to achieve accuracy and clarity.

I recently read a wonderful article by Prof. Raghavendra Gadagkar, which elegantly makes a case for why scientist must write to a wider audience, and why the boundary between the roles of a scientist and a science writer should be diminished.

The article reads like a manifesto for science communication, as the author himself states at the end. I strongly recommend this article to anybody who is involved in pursuit of science.

Perhaps I will add one more point to what the author mentions. There might be a very important role for science writers who can take emerging developments in science literature and translate it into vernacular language. An authentic scientific voice in regional language can really impact not only the interest of students, but also of the general public, including policy makers and politicians.

India and the world needs more science, and scientific way of life. Therefore, doing science is as important as communicating it. Prof. Gadagkar’s article makes an excellent case for this.

37. A call from Varanasi

Today (4th Feb, 2021), I had a strange but pleasant experience.

At around 5pm, I got a call on my office number from a person named Anil Tiwari from Varanasi. He told me that he had some questions related to science and he wanted to get some clarifications. Initially, I was a bit reluctant to engage in the conversation, as he was incoherent and probably a bit nervous. Then, he gradually gained some confidence, and mentioned that he was not convinced that the speed of light is a constant irrespective of the frame of reference in which it was measured, and he had difficulty in understanding the concept of light and its connection to electricity and magnetism. This led to our conversation on Maxwell’s electromagnetic theory and Michelson-Morley’s experiment to (dis)prove ether. I also urged him to look up history of light and Michelson’s lifelong obsession of measuring velocity of light. As our conversation went further, he mentioned that he wishes to understand the concept of light in its complete depth, and asked me for further references. I mentioned that he should read Feynman’s book on QED, and told him that Feynman’s explanation of interaction of light with matter was possibly one of the deepest understanding of nature we have.

All this conversation was in Hindi, and perhaps, my lengthiest attempt to talk science in that language. Then, Anil thanked me for the time I spent (around 10 to 15 min), and we were about to hang-up. Casually, I asked him how he could find my number, and he told me that he googled about light and matter, and he stumbled upon my webpage from which he could get the number. Then, I asked him if he was a student and where was he studying?  He hesitantly replied that he had completed his BSc many years ago, and now he was a farmer working in the fields, and was still interested in science. In order to spend time in the evening, it seems he watches science videos on YouTube and came across many interesting topics, of which velocity of light caught his attention recently, and he had many questions regarding this. I was elated to know about this, and strongly encouraged him to look up and study some good books including Feynman’s lectures and many other resources freely available on the internet.

Then we ended the call, and I could feel that both of us had an enjoyable conversation in science. Undoubtedly, this was a small but a pleasant experience for me, and reinforces my faith in science, in India, and importantly in humanity….      

36. Science for…?

As student of science and as a practicing researcher one can always ask why should we do science?

If you look at this question from an utilitarian viewpoint, especially in times where vaccination is in the news (for right and wrong reasons), one does not need to give strong justifications for doing science. Its relevance is there to see in our lives and its impact is it ubiquitous.

So, do scientists always think about an application while doing science? The answer is : not always.

In fact many important discoveries and inventions in science, even those which turn out to have huge applications, were not envisaged with an application in mind.

An illustration of this aspect is beautifully communicated in the above video by Prof. P. Balaram, who is an excellent scientist at IISc, and also served as its director in the past.

I should mention that during my PhD course work days, I had the privilege of taking professor Balram’s molecular spectroscopy course in the molecular biophysics unit of IISc.

Being a student of physics I was introduced to the fascinating concepts of molecular spectroscopy from biophysics and biochemistry viewpoint. I learnt a lot about molecules, their stereochemistry and their interaction with light in this fantastic course. Even to date, when I think about chirality in the optical physics, some of the lessons learnt during this course has come extremely handy. Undoubtedly this was one of the best courses I have attended.

General advice, especially for students in physics, is in order to get a deeper intuition in physics it is good to study some fundamental aspects in chemistry and biology. For sure ones understanding of concepts such as chirality and symmetry is enriched if we look at these topics from the chemistry and biology viewpoint.

Similarly students of chemistry and biology can get a deeper insight into the structure and dynamics of molecules if they understand the nature of light in the context of polarization, phase and momentum etc.

After all the universe we live in does not discriminate between the disciplines we used to study it…