Author: G.V. Pavan Kumar

Namaste, Hola & Welcome from G.V. Pavan Kumar. I am a Professor of Physics at the Indian Institute of Science Education and Research, Pune, India. My research interests are : (1) Optics & Soft Matter: Optically Induced Forces – Assembly, Dynamics & Function; (2) History and Philosophy of Science – Ideas in Physical Sciences. I am interested in the historical and philosophical evolution of ideas and tools in the physical sciences and technology. I research the intellectual history of past scientists, innovators, and people driven by curiosity, and I write about them from an Indian and Asian perspective. My motivation is to humanize science. In the same spirit, I write and host my podcast Pratidhvani – Humanizing Science.

Why do people climb mountains?

When I was growing up, I always wondered about this.   If the aim was to go to the top of the mountain, why not just take a helicopter and reach the summit?  Then, I gradually realized that people climb mountains for a different reason: happiness through temporary pain.  This transient, painful process of climbing motivates people to take up the challenge.  If you look at the amount of time a climber spends on reaching the summit, it will be minuscule compared to the climbing time.  The elaborate process and the preparation make climbing not only an adventure but also a meditation.  There is joy in reaching the summit, but happiness comes from the climb, which starts as a painful step.  Joy, in that way, is temporary. The climb, which is the process, is the happiness. 

Then, can the climber focus on the climb and forget about the summit and destiny?  Over the years, I have realized that any journey requires a point of reference, a temporary destiny.  It tells the climber roughly which direction they must head towards to reach the summit – destiny.  However, once this reference point is decided, it is better to forget about the summit and focus on the next step.  Interestingly, each step becomes a mini-goal, keeping the motivation alive.  The way to reach the summit is through multiple steps.  Therefore, it is the repetition of steps that makes the journey.  Even as they approach the summit, it is only through the individual step that they reach it.  As they reach the summit, what has taken up the climber is still a tiny step.  But this step was preceded by another step, and another preceded that.  Then, they realize these steps are permanent, and the summit is a temporary stop.  There is the realization that the summit is transient and the steps are permanent.  Somehow, a tiny bit of discomfort with each step culminated in happiness.  A transformation has happened.    

Conversation with Dibakar Roy Chowdhury

Dibakar Roy Chowdhury is a professor of physics at Mahindra University. https://www.mahindrauniversity.edu.in/faculty/prof-dibakar-roy-chowdhury/

With a rich background in research, including stints at prestigious institutions like Los Alamos National Laboratory and the Australian National University, Dr. Roy Chowdhury has significantly contributed to our understanding of light-matter interaction at the micro-nano scale. Listen to this ‘Emergence’ series, where we explore his groundbreaking research in metamaterials, plasmonics, and more through his academic journey until now. Specifically, we discuss the opportunities and challenges of doing experimental research at a private university in India.

Listen as we humanize science.

Apple and Google podcast

References :

  1. “Dibakar Roy Chowdhury.” n.d. Mahindra University. Accessed May 14, 2024. https://www.mahindrauniversity.edu.in/faculty/prof-dibakar-roy-chowdhury/.
  2. “‪Dibakar Roy Chowdhury – ‪Google Scholar.” n.d. Accessed May 14, 2024. https://scholar.google.co.in/citations?user=63q8bcwAAAAJ&hl=en.
  3. “Dibakar r Chowdhury (@DibakarRC) / X.” n.d. X (Formerly Twitter). Accessed May 14, 2024. https://twitter.com/DibakarRC.

Election in Pune and Zero shadow day

Today is election day in Pune (Lok Sabha), and I voted.

Today is also a ‘zero shadow day’ in Pune. The sun is exactly over our head (zenith), and no angle is subtended by the shadow. In the pic, the sun is captured at its zenith.

Caution: don’t look at the sun directly. This image was captured wearing filtered glass

Check the webpage of the Astronomical Society of India linked below. It has some good explanations and geographical locations in India where zero shadow day is observed.

Zero Shadow Day

Conversation with Sundar Sarukkai

Sundar Sarukkai is a philosopher who specializes in the natural and social sciences.

His webpage : https://www.sundarsarukkai.in/

As a professor and visiting faculty at various institutions, he has made significant contributions to the field. Sarukkai is the author of numerous books, including “Philosophy for Children,” “Translating the World,” “Philosophy of Symmetry,” and “What is Science?” He has also co-authored works exploring Indian philosophy, caste, and democracy. Sarukkai is the founder of Barefoot Philosophers, an initiative to bring philosophy to children and the public. With his diverse expertise and passion for accessible philosophy, Sarukkai is a captivating thinker in the intellectual landscape.

Listen, as we humanize science.

Note: The audio in the first 10 min is of lower quality

References :

  1. “Sundar Sarukkai, Philosopher, Writer | Barefoot Philosophers.” n.d. Sundar Sarukkai. Accessed May 4, 2024. https://www.sundarsarukkai.in.
  2. Barefoot Philosophers, dir. 2024. A Conversation with Sundar Sarukkai – Philosophy of Science Workshop (2024). https://www.youtube.com/watch?v=XszjdsCvCV4.
  3. Christ University, Bangalore, dir. 2023. Dr Sundar Sarukkai Talk on Philosophy and Literature. https://www.youtube.com/watch?v=1tL1GbPYkfs.
  4. DC Books, dir. 2024. The Cracked Mirror: An Indian Debate on Experience and Theory | Sundar Sarukkai | Babu Thaliath |KLF. https://www.youtube.com/watch?v=gMMoI0ZQgS0.
  5. Toor, Sanchit. 2023. “‘The Challenge Was to Produce a Language, Not Just Use What Is Accepted as Correct’: Sundar Sarukkai.” Text. Scroll.In. https://scroll.in. April 22, 2023. https://scroll.in/article/1047684/the-challenge-was-to-produce-a-language-not-just-use-what-is-accepted-as-correct-sundar-sarukkai.

How confinement leads to emergence ?

New vlog post: I take, e.g. from the game of cricket (ft. Laxman, Dravid), soft matter physics, ants, Feynman’s seminar & a few other references to explain the emergence, self-organization and spontaneous order in our world

References:

“Second Test, 2000–01 Border–Gavaskar Trophy.” 2024. In Wikipedia. https://en.wikipedia.org/w/index.php?title=Second_Test,_2000%E2%80%9301_Border%E2%80%93Gavaskar_Trophy&oldid=1207694527.

Araújo, Nuno A. M., Liesbeth M. C. Janssen, Thomas Barois, Guido Boffetta, Itai Cohen, Alessandro Corbetta, Olivier Dauchot, et al. 2023. “Steering Self-Organisation through Confinement.” Soft Matter 19 (9): 1695–1704. https://doi.org/10.1039/D2SM01562E.

arxiv link : https://arxiv.org/abs/2204.10059

FeynmanChaser, dir. 2008. Feynman Chaser – Imagination in a Straitjacket. https://www.youtube.com/watch?v=IFBtlZfwEwM.

“Why Constraints Are Good for Innovation.” n.d. Accessed May 3, 2024. https://hbr.org/2019/11/why-constraints-are-good-for-innovation.

Tromp, Catrinel, and John Baer. 2022. “Creativity from Constraints: Theory and Applications to Education.” Thinking Skills and Creativity 46 (December): 101184. https://doi.org/10.1016/j.tsc.2022.101184.

Conversation with Mayurika Lahiri

Mayurika is a cancer biologist and a senior faculty member at IISER Pune : https://www.iiserpune.ac.in/research/department/biology/people/faculty/regular-faculty/mayurika-lahiri/289

In this episode, we discuss her intellectual journey, how she became interested in molecular and cancer biology, her initiatives related to breast cancer research, and her role in the Genome India project.

We had a wonderful conversation about various aspects of science in India and tried to understand it through the lens of gender equity. Mayurika speaks about women’s representation in science and how and why it should improve.

There are many interesting strands in this conversation, and each branch enriches the discussion.

Listen, as we humanize science.

Google and Apple podcast

References :

1.      “Mayurika Lahiri – IISER Pune.” n.d. Accessed April 29, 2024. ⁠https://www.iiserpune.ac.in/research/department/biology/people/faculty/regular-faculty/mayurika-lahiri/289⁠.

2.     “Webpage of Her Lab.” n.d. Lahirilab. Accessed April 29, 2024. ⁠https://lahirilab.wixsite.com/lahirilab⁠.

3.     “Dr. Mayurika Lahiri: A Flagbearer of Breast-Cancer Research.” n.d. Accessed April 29, 2024. ⁠https://scicomm.iiserkol.ac.in/docs/1/pages/mayurika.html⁠.

4.     IISER Pune, dir. 2019. Episode 4, SciTalk@SMC Feat. Dr. Mayurika Lahiri (Associate Professor, IISER Pune). ⁠https://www.youtube.com/watch?v=gNIpb2cywtg⁠.

5.     IISER Pune Science Activity Centre, dir. 2023. International Women’s Day Celebration: Talk by Dr  Mayurika Lahiri. ⁠https://www.youtube.com/watch?app=desktop&v=S4l1HYxSKaE⁠.

6.     “Mayurika Lahiri (@MayurikaLahiri) / X.” 2024. X (Formerly Twitter). April 12, 2024. ⁠https://twitter.com/MayurikaLahiri⁠.

Why write interesting papers ?

A lesson I keep learning from Daan Frenkel: write interesting research papers. Thanks to Arghya Dutta (on X), who brought the paper below to my notice. https://arxiv.org/abs/1211.4440

Sometimes, interesting, well-written papers can have a deeper impact. Even otherwise, it would add clarity.

Scholarship + interesting writing >>>> prestige of the journal.

Don’t worship journals.

A common question when I say so is: what about academic assessment for jobs and promotion?

My answer is that academia (still) values consistent, scholarly output in reasonable journals.

It is very hard to reject scholarship. Aim for this as it is under your control.

Why liquid state is amazing ?

One of the research questions I am interested in is how light interacts with the liquid state of matter?

A related question is how is it different from the interaction of light with a solid state?

Specifically, I am interested in understanding how optical forces can influence the structure of liquid matter and if one can control such interaction.

The liquid state of matter is ubiquitous but not as well understood as the solid or gaseous state of matter. This is because the nature of interaction in liquid is intermediate between the other two states, and the way molecules and atoms interact depends on parameters that include interaction in classical and quantum physics.

Jean Perrin – Image courtesy: Nobel Foundation archive.

A connected question to this problem is how liquid behaves under and out of equilibrium. This classification is again non-trivial as it depends on the spatio-temporal scales under which one is making an observation. An important aspect of the liquid state is the local and global fluctuations, which complicate the problem. Jean Perrin, in his 1926 Nobel lecture, alludes to this problem very succinctly.

There is still much to learn about the liquid state, and enormous progress has been made from experimental and theoretical viewpoints. But there are some fascinating ‘landscapes’ yet to be fully explored in this domain.

Sometime in the future, I will write more about how this is done and what the historical context is, especially from an optical force viewpoint.

On a related note :

Here is an illustration of the Brownian motion of gold nanoparticles..imaged using a dark field optical trapping microscope..this is a custom-built system in my lab. We study the effect of laser traps on Brownian dynamics..more on this later.