An amazing story of how Maxwell figured out the connection between electricity, magnetism and light…
Category: Uncategorized
51. A case for Science + Philosophy
Linked below is an interesting article written by a Phd student.
I am glad to see a research student writing about it, and importantly it appreciates the diversity of thought, and ends well with a disclaimer.
“My background, and therefore my suggestions, are mainly rooted in the Western tradition, but I aim to continue diversifying my education.”
In my opinion philosophy is a subject that ‘many’ scientists are reluctant to entertain, and sometimes are dismissive of it. Many of the great ones, including Feynman and Weinberg have criticized it. (If I’m correct, Einstein was not one among them)
But, with the emergence of technology such as artificial intelligence, machine learning, genetic engineering and stem cell research, philosophical questions become important. Even otherwise, asking philosophical questions about any work helps us appreciate aspects such as: what it is to do work and how our scientific thought and expression interacts with the external world. In a way it is path to self realization.
I am no way dismissing the criticism of great scientists, who may have had a valid point in how philosophical enquiry is conducted. But I think it is not prudent to just discard a school of thought that lays the foundation of how humans think and evolve.
It is important for us to appreciate that Manhattan project was a remarkable scientific achievement, but the consequences had deep and disastrous societal implications. In my opinion what was badly missing there was deeper philosophical enquiry. In an essence, it was a collective human failure, where science was right, and the philosophy was wrong.
Philosophical enquiry not only helps in the evolution of science, but also helps in understanding its interface with societies. And, as we know, how science interacts with western and eastern society can have different consequences.
The case in point is the business of science tuitions in India, and the emergence of online educational platforms which are worth a billion dollars or more. Remember that the science which is been taught in these online tuitions is essentially the same across the globe, but how the society consumes, and for what reason, is very different.
On the same footing, it also says why so many Indians are attracted to godmen and there unscientific thought processes. It may be because people may have got only the scientific, utilitarian aspect of the knowledge, but not the philosophical component. In this case the concept of critical thinking, which is by no means alien to the eastern philosophy, has been lacking in the mix of things. As an Indian society, with the rich tradition of debate and discussion, we cannot afford to lose this culture.
This is where philosophy matters : western, eastern, and their combinations.
It is important for us, humans, to combine science with philosophy. Otherwise, science will be an ill defined vector : large in magnitude without any direction.
50. Nanowire-nanoparticle Raman Antenna

We have a new paper in J. Optics (IOP)
Mirror enhanced directional out-coupling of SERS by remote excitation of a nanowire-nanoparticle cavity
Sunny Tiwari Adarsh Bhaskara Vasista Diptabrata Paul experimentally show how a nanowire-nanoparticle junction placed on a gold mirror can lead to extreme directionality in Raman emission
https://doi.org/10.1088/2040-8986/ac2dd8
Arxiv : https://arxiv.org/abs/2104.13121
48. Test Match Cricket and Research
My favourite sport to watch is test match cricket. It has the ebb and flow of a long drawn, thoughtful contest where temperament is as important as skills. This was evident in the century innings of Rohit Sharma. Although I could not watch the innings live, I did catch up on the highlights, and as expected Rohit’s batting was sublime.
In limited over cricket, Rohit is undoubtedly one of the most accomplished batter ever, with two double centuries in one day internationals. He also is one of the most stylish batter who can score runs on any continent. Unfortunately, he has not accomplished the same reputation in test match cricket. But in the ongoing tour of England, there are some interesting developments. He has taken the initiative to stay at the crease for a long period, and has tightened his game which has let him to score runs as an opener. Mind you, opening batting in overcast English conditions is never an easy task, and it is a remarkable achievement that he has been able to do so with reasonable success.
Coming back to yesterday’s innings Rohit occupied the crease for more than five hours, and played out more than 200 balls, which does require skill and concentration. This undoubtedly lead to fruitful result in him scoring 100. What more, his first hundred overseas came up with a spectacular six.
Now, what lessons, especially in the context of research, can we extract from Rohit success in England?
First and the foremost is the consistency. Many a times, in research, good ideas emerge after consistently working on a particular area. A quote attributed to Linus Pauling puts it well on the lines : “to have a good idea you need to have many ideas”. Rohit has been playing for a long time, and his experience has indeed helped him to adapt on this tour to be consistent.
Second, no matter how skilled or talented you are, you cannot accomplish big things without the right temperament and perseverance. Research and test match cricket is very similar in that way. Compare Rohit’s limited over cricket record versus the test record.
Third, there is enough room in the chosen area of research to be creative. All researchers need not do the same kind of work, and there is enough room for individuality in the kind of research one can do. Rohit doesn’t play like Virat or Pujara, but still contributes in his own way.
Finally, the right ecosystem to flourish. Generally in research, the most important aspect is the people – students, colleagues and staff. Next comes the infrastructure and funding. The order that I have chosen to mention this is deliberate, because having the right people, with right mindset, is more important than having more money. Indian cricket has always been quite rich in finances, but over the last 15 years or so, a lot of professional people, like Dravid, have taken up the supporting rule, which has made a positive difference.
Whether India will win the series or not, we will have to see. But the fact that even during the pandemic we are entertained with high quality test match cricket is a tribute to the sporting spirit of the players. In many ways, it also motivates us to do good research.
Long live test match cricket !
39. Paper on nanophotonics of 2D material
We have a paper appearing in Advanced Photonics Research, in collaboration with the group of my colleague Atikur Rahman.
One of my PhD students, Shailendra Kumar Chaubey, is passionate about nanophotonics of 2D materials and its interface with plasmonic nano-elements. In collaboration with Atikur Rahman’s group, Shailendra, Gokul, Diptabrata Paul and Sunny Tiwari have experimentally shown directional photoluminescence from WS2 monolayer sandwiched between a plasmonic nanowire and a gold film.
Such directional emission is a vital step in photonic signal processing on a chip, and can serve as a solution-processed, soft platform to study optical emission in nonlinear and quantum optical regimes.
Personally, I am intrigued by the prospect of using optical trapping and assembly on such 2D materials to influence emission characteristics. Work is under progress in this direction…more on this later..
Link to the the arxiv version of the article is below
30. Post-Nobel blues and blackbody science
Generally, when the Nobel prizes are announced in October, it is an occasion to celebrate science. The people who get the prize are shot into the limelight, and deservingly so. It is also an occasion where the subjectivity behind these prizes get exposed.
One such case is the invention of laser and the Nobel prize related to it. People who work with lasers and who are aware of its history will readily recognise that Theodore Maiman, the person who actually created the first working laser at optical wavelength, did not receive the Nobel prize.
It has been around 60 years since the invention of lasers, and John Dudley, in a recent commentary, has briefly summarised the context in which black body radiation science was initiated and its evolution towards lasers and the subsequent nomination and award of Nobel Prize. Some of the numbers related to nomination, that Dudley furnishes, is very interesting:
“Maiman, despite being the first to see laser emission, never won the Nobel Prize, and neither did Jim Gordon. Whilst it is natural to consider these omissions as major oversights by the Nobel Committee, the available Nobel Prize archives reveal that the lack of any Nobel recognition for Maiman and Gordon may simply be linked to the fact that they were not strongly supported by the broader physics community at the time. In particular, starting as early as 1958, Charles Townes had been nominated 75 times for the Nobel Prize, including 29 nominations for the year in which he won. In contrast, based on what we know of the nomination archives (which are accessible until 1966), Gordon was nominated only once in 1963 and Maiman only once in 1964.”
Interestingly, I also learnt the initial reason why black body radiation was studied in late 1800s. To my surprise, it seems it was initiated purely for an economic and practical purpose, which turned out to be a trigger point for the revolution in quantum mechanics. As Dudley says:
“In fact, it is not widely appreciated that these studies were not initially motivated by questions of fundamental scientific curiosity, but were rather stimulated by a very practical and economic problem. In particular, the city of Berlin at the time was choosing between gas and electric lighting, essentially the same problem as we have had in recent years in switching from incandescent and fluorescent lights to LEDs. Naturally, when making such a decision, standardizing the spectral content of the different light sources was a critical first step, and it was this that drove experiments to measure precision radiation curves of sources at different temperatures. Theoretical work by Wien was able to connect the peak emission wavelength and the source temperature, but explaining the shape of the emission curve was only possible with the introduction of energy quantization by Max Planck in 1900.”
This highlights how nonlinear the evolution of ideas are, and how new directions in science can be motivated and triggered by something which is purely practical. In some other cases, great science has also evolved from “blue sky” curiosity driven research, as in the case of laser, which has enormous practical utility.
Perhaps there lies the beauty of science: if you pay attention, everything is an inspiration…