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.

Conversation with Dibyendu Nandi

Conversation with Dibyendu Nandi – Solar Astrophysics & Space Weather

Dibyendu Nandi is a Professor at IISER Kolkata.

His webpage : https://www.iiserkol.ac.in/~dnandi/

His research includes solar astrophysics – sun spots, magnetohydrodynamics and the recent Aditya L1 mission.

In this episode, we discussed his biography, research and teaching astrophysics, his thoughts on science in India, a short segment in Bengali and many other things.

Listen as we humanize science.

youtube (audio) :

spotify :

on google podcast: https://podcasts.google.com/feed/aHR0cHM6Ly9hbmNob3IuZm0vcy9lMTcyMGUwYy9wb2RjYXN0L3Jzcw/episode/MGJkODBhODgtOTc1Zi00NGI5LTkzZDUtZmU5ZjEwMzRjNGI5?sa=X&ved=0CAUQkfYCahcKEwiAh7XouP6BAxUAAAAAHQAAAAAQAQ

on apple podcast: https://podcasts.apple.com/us/podcast/ep-24-conversation-with-dibyendu-nandi-solar/id1687861465?i=1000631666686

References :

“Center of Excellence in Space Sciences India | CESSI.” Accessed October 14, 2023. http://www.cessi.in/.

Chapter 8.1: Understanding the Sun | Dibyendu Nandi, 2023. https://www.youtube.com/watch?v=KtKmaKgfa9Q.

“Dibyendu Nandi.” In Wikipedia, October 4, 2023. https://en.wikipedia.org/w/index.php?title=Dibyendu_Nandi&oldid=1178592189.

“‪Dibyendu Nandy (/Nandi)‬ – ‪Google Scholar‬.” Accessed October 14, 2023. https://scholar.google.com/citations?user=QFFFmQcAAAAJ&hl=en.

“Homepage of Dibyendu Nandi.” Accessed October 14, 2023. https://www.iiserkol.ac.in/~dnandi/.

Nandi, Dibyendu. “Aditya-L1 Mission Pursues the Enigma of Space Weather.” The Hindu, September 11, 2023, sec. Science. https://www.thehindu.com/sci-tech/science/aditya-l1-sun-space-weather-forecast/article67288282.ece.

“ADITYA-L1 Mission Details.” Accessed October 14, 2023. https://www.isro.gov.in/Aditya_L1-MissionDetails.html.

———. “Unravelling the Mysteries of the Sun.” Nature India, August 31, 2023. https://doi.org/10.1038/d44151-023-00127-8.

Nandy, Dibyendu, and Arnab Rai Choudhuri. “Explaining the Latitudinal Distribution of Sunspots with Deep Meridional Flow.” Science 296, no. 5573 (May 31, 2002): 1671–73. https://doi.org/10.1126/science.1070955.

X (formerly Twitter). “Dibyendu Nandi (@ydnad0) / X,” October 14, 2023. https://twitter.com/ydnad0.

Conversation with Sudeshna Sinha

Sudeshna Sinha is a Professor at IISER Mohali. She works on areas related to nonlinear dynamics, complex systems and networks.

Here webpage : https://web.iisermohali.ac.in/dept/physics/Sudeshna_Sinha.html

In this episode we discussed her biography, career trajectory, her current research interest, thoughts on science in India, a short segment in Bengali and her future plans.

Listen, as we humanize science…

on youtube :

on spotify :

  1. “DPS – People – Sudeshna Sinha.” Accessed October 1, 2023. https://web.iisermohali.ac.in/dept/physics/Sudeshna_Sinha.html.
  2. “Dr. Kapil Hari Paranjape – IISER Mohali.” Accessed October 2, 2023. https://www.iisermohali.ac.in/faculty/dms/dr-kapil-hari-paranjape.
  3. “Home | ICTP.” Accessed October 2, 2023. https://www.ictp.it/.
  4. Murali, K., Manaoj Aravind, and Sudeshna Sinha. “Noise-Aided Invertible Logic from Coupled Nonlinear Systems.” Physical Review Applied 20, no. 3 (September 19, 2023): 034041. https://doi.org/10.1103/PhysRevApplied.20.034041.
  5. “Prabodh Chandra Bagchi.” In Wikipedia, August 8, 2023. https://en.wikipedia.org/w/index.php?title=Prabodh_Chandra_Bagchi&oldid=1169380835.
  6. Sinha, Sudeshna. “Noisy Uncoupled Chaotic Map Ensembles Violate the Law of Large Numbers.” Physical Review Letters 69, no. 23 (December 7, 1992): 3306–9. https://doi.org/10.1103/PhysRevLett.69.3306.
  7. Sinha, Sudeshna, and William L. Ditto. “Dynamics Based Computation.” Physical Review Letters 81, no. 10 (September 7, 1998): 2156–59. https://doi.org/10.1103/PhysRevLett.81.2156.
  8. “Sudeshna Sinha.” In Wikipedia, September 12, 2023. https://en.wikipedia.org/w/index.php?title=Sudeshna_Sinha&oldid=1175056931.
  9. “‪sudeshna Sinha – ‪Google Scholar.” Accessed October 1, 2023. https://scholar.google.co.in/citations?user=yc87OXUAAAAJ&hl=en.
  10. The Dynamics Lab – IIT Delhi. “Home.” Accessed October 2, 2023. https://ramramaswamy.org/.

2023 Nobel in Sciences – A few observations and questions

One of the interesting aspects of the Nobel Prize in Sciences this time is that all the 8 laureates are experimentalists. This is not to underplay the contribution of theoreticians but to emphasize the point that experimental observations are central to the progress of sciences and follow-up technology. Also note that many of these laureates were equally well-versed in theoretical ideas, and hence were able to connect the abstract to the real. An effective way to do science.

Another aspect is that all the experimentalists are strongly anchored in the West. They have performed all their work in an ecosystem that has supported their efforts, even when their ideas were not well known. A case in point is Katalin Karikó (one of the medicine/physiology laureates). Although U Penn treated her badly, she was still able to sustain her research thanks to the research-driven business ecosystem in the West, including the USA and Germany, where she could establish herself in the biotech research industry. This means the Western research ecosystem, including its businesses, was open enough to allow someone who was almost discarded by the US academic system. Karikó’s is a great story, but we must not forget that eventually, the system in which she worked recognized her contribution.

Now, some things to ponder – what if Karikó had moved to a place such as India? Could she have survived and thrived in our research ecosystem? If she had moved, was our academic and market ecosystem open to welcome her, take her expertise, and utilize it effectively? Answers to these questions are not straightforward but may indicate where we are as a research ecosystem. 

2023 Nobel in Physics – Initial thoughts

One should not be surprised nowadays if a Nobel prize in physics goes to something related to light. As a person working in optics and light-matter interaction, I welcome any recognition of one of the most profound aspects of nature: light. This time, the prize has gone to some great experimental effort dating back to the late 1980s to early 2000s when amazing progress was made in three aspects related to the prize: a) higher harmonic generation of light in rare gases, b) production of a train of attosecond light pulses, and c) eventually production of single attosecond light pulses that can interact with matter, especially electrons in matter. Such an interaction can lead to the mapping of dynamics of quantum entities such as electrons and will have far-reaching consequences in probing the internal degrees of molecules and atoms. The scientific information published by the Nobel Committee has wonderful illustrations and is worth reading.

This time, the Nobel Prize website has published a fantastic set of illustrations to convey the relevance of the research. The above one shows the spectrum of temporal scales. It elegantly illustrates the breadth of the scale – attosecond to heartbeat:: Heartbeat to the age of the universe.. Oh, how beautiful science is!

Via Twitter, thanks to a student who was attending a lecture by Anne (one of the Nobel laureates), we got to see continuing her lecture even after a Nobel announcement. Now that is the spirit of academics!

This is the fundamental paper that triggered higher harmonic generation in gases and laid the foundation for attosecond pulse generation. of today, the impact factor of this journal is 1.6. The impact is not proportional to the impact factor of a journal

अहिंसा, सत्याग्रह

अहिंसा, सत्याग्रह

Gandhi lived a life in pursuit of non-violence and truth (the meaning of the above two words in Devanagari script).

The beauty of Gandhi’s life is his astonishing honesty. You can still disagree with him on certain aspects of his politics, including economics, and yet engage with his ideas and learn something deep. If you observe his writings, he was always engaging in disagreement and yet never dismissive of an opposing idea. He subjected himself to scrutiny of his character and yet emerged with a deeper meaning of flaws and self-introspection. Talk about confidence!

This is perhaps the hallmark of his education. A lesson he took not only as a teacher but also as a student of life.

Probably Gandhi’s most innovative idea was to recognize the deep philosophical and human aspects of life and incorporate them into his work. He practiced what he preached, which is a rarity. Einstein realized this very early (see the quote).

The two ideas mentioned at the beginning have stood the test of time, and I think they will continue to serve as benchmarks of human intellectual life. That is the lesson I take away from his life.

Long live अहिंसा and सत्याग्रह…

New paper – Emergence of Directional Rotation

We have a new paper to appear in ACSPhotonics. Great effort by Rahul Chand, Chaudhary Eksha Rani and Diptabrata Paul from our group. We ask : How & why does directional rotation emerge in an optical trap of thermally active (smaller) + passive colloidal combination ?

By combining light absorbing colloid (smaller one) with a normal colloid (bigger ones), we can observe directional rotation in a 2D optical trap. What determines the rotation direction is the relative position of the active colloid in the assembly.

One can switch the direction of rotation, by changing the relative position of active colloid.

For the rotation to emerge, the symmetry of the colloidal arrangement matters. As you see, if there are two active colloids (smaller ones) are symmetrically positions with respect to passive colloids (bigger one), we do not observe rotation.

There is a lot more interesting stuff and explanation of the observed effect discussed in our paper. You can read the pre-print of the our paper in arxiv : https://arxiv.org/abs/2309.12740

Conversation with Vishwesha Guttal

Vishwesha is a physicist turned ecologist. He is an associate professor in centre for ecological sciences at Indian institute of science Bengaluru

His webpage :  https://ces.iisc.ac.in/?q=user/36.

In this episode we discuss his

  • biography
  • education and research experience at IIT Kanpur,  Ohio State University, Princeton and IISc
  • laboratory research interests
  • love for teaching
  • fatherhood and work-life balance
  • interests in philosophy of science
  • thoughts on science in India

Listen, as we humanize science…

Youtube audio :

spotify :

google podcast : https://podcasts.google.com/feed/aHR0cHM6Ly9hbmNob3IuZm0vcy9lMTcyMGUwYy9wb2RjYXN0L3Jzcw/episode/YTQ2YTRiOTYtNjYxYy00MTMxLTgzMTMtM2ZlNzhiZGQwYTk4?sa=X&ved=0CAUQkfYCahcKEwjQvPX338mBAxUAAAAAHQAAAAAQAQ

apple podcast : https://podcasts.apple.com/us/podcast/ep-22-conversation-with-vishwesha-guttal-physicist/id1687861465?i=1000629271604

References :

(1)Theoretical Ecology and Evolution Laboratory. Theoretical Ecology and Evolution Laboratory. https://teelabiisc.wordpress.com/ (accessed 2023-09-21).

(2)Vishwesha Guttal. https://ces.iisc.ac.in/?q=user/36 (accessed 2023-09-21).

(3)‪Vishwesha Guttal‬ – ‪Google Scholar‬. https://scholar.google.com/citations?user=2ew94JcAAAAJ&hl=ja (accessed 2023-09-21).

(4)Physics | IIT Kanpur. https://www.iitk.ac.in/phy/ (accessed 2023-09-21).

(5)Debashish Chowdhury. https://www.iitk.ac.in/new/dr-debashish-chowdhury (accessed 2023-09-21).

(6)Home. Vijaya College. https://vijayacollege.ac.in/ (accessed 2023-09-21).

(7)National College Basavanagudi. http://ncbgudi.com/ (accessed 2023-09-21).

(8)2012_Guttal_brief_intro_phil_science.pdf. Google Docs. https://drive.google.com/file/d/0B9WKrHfGyqu4My1RNU1Da2pBNzQ/view?usp=drive_open&usp=embed_facebook (accessed 2023-09-21).

(9)Shanker-Guttal-2021-CurrentScience.pdf. Google Docs. https://drive.google.com/file/d/1N6l3w9P8XVAEVp9v5zdc_1aGw3ej6IPn/view?usp=sharing&usp=embed_facebook (accessed 2023-09-21).

(10)Guttal, V. Ecology: From Individuals to Collectives: A Physicist’s Perspective on Ecology. Reson2014, 19 (4), 368–375. https://doi.org/10.1007/s12045-014-0041-y.

(11)Ciriyam Jayaprakash | Department of Physics. https://physics.osu.edu/people/jayaprakash.1 (accessed 2023-09-21).

(12)Iain Couzin. Wikipedia; 2023.

(13)Jhawar, J.; Morris, R. G.; Amith-Kumar, U. R.; Danny Raj, M.; Rogers, T.; Rajendran, H.; Guttal, V. Noise-Induced Schooling of Fish. Nat. Phys.2020, 16 (4), 488–493. https://doi.org/10.1038/s41567-020-0787-y.

(14)Vishu Guttal !! ವಿಶ್ವೇಶ ಗುತ್ತಲ್ (@vishuguttal) / X. X (formerly Twitter). https://twitter.com/vishuguttal (accessed 2023-09-21).

(15)ಕನ್ನಡ | Theoretical Ecology and Evolution Laboratory. https://teelabiisc.wordpress.com/category/%e0%b2%95%e0%b2%a8%e0%b3%8d%e0%b2%a8%e0%b2%a1/ (accessed 2023-09-21).

(16)Thale-Harate Kannada Podcast Ep. 21: ವಿಜ್ಞಾನ ಪ್ರಾಧ್ಯಾಪಕನ ಬದುಕು-ಬವಣೆ.The…; 2019. https://www.youtube.com/watch?v=8N9jH_p4tlI (accessed 2023-09-21).

(17)ವಿಜ್ಞಾನಿಯನ್ನು ಕೇಳಿ [ಕನ್ನಡ] ಭಾಗ ೧; 2020. https://www.youtube.com/watch?v=BNhqyd5CMVg (accessed 2023-09-21).

Video on Shechtman and Nobel predictions…

Campanario, Juan Miguel. “Rejecting and Resisting Nobel Class Discoveries: Accounts by Nobel Laureates.” Scientometrics 81, no. 2 (November 1, 2009): 549–65. https://doi.org/10.1007/s11192-008-2141-5.

“Dan Shechtman.” In Wikipedia, September 20, 2023. https://en.wikipedia.org/w/index.php?title=Dan_Shechtman&oldid=1176268332.

“David Smith Negative Refraction – Google Search.” Accessed September 24, 2023. https://www.google.com/search?sca_esv=567971749&rlz=1C1CHBF_enIN947IN947&q=david+smith+negative+refraction&tbm=isch&source=lnms&sa=X&ved=2ahUKEwj65sitgsOBAxWvbvUHHdXgBDgQ0pQJegQIDBAB&biw=1163&bih=554&dpr=1.65#imgrc=ETQJRC1YLQoZIM.

Duke Electrical and Computer Engineering. “David R. Smith.” Accessed September 24, 2023. https://ece.duke.edu/faculty/david-smith.

“Eli Yablonovitch – Google Search.” Accessed September 24, 2023. https://www.google.com/search?gs_ssp=eJzj4tTP1TcwyiqryDFg9BJIzclUqExMysnPyy_LLEnOAACJLwn8&q=eli+yablonovitch&rlz=1C1CHBF_enIN947IN947&oq=eli+ya&aqs=chrome.2.69i57j46i512l2j0i512j46i512j0i512l4.7471j0j7&sourceid=chrome&ie=UTF-8.

“Federico Capasso – Google Search.” Accessed September 24, 2023. https://www.google.com/search?gs_ssp=eJzj4tTP1TdIyi0xrDJg9BJIS01JLcpMzldITixILC7OBwCI3QnT&q=federico+capasso&rlz=1C1CHBF_enIN947IN947&oq=fedrico+capaso&aqs=chrome.1.69i57j46i13i512j0i13i512l2j0i13i30l5.5850j0j7&sourceid=chrome&ie=UTF-8.

“John Pendry – Google Search.” Accessed September 24, 2023. https://www.google.com/search?q=john+pendry&rlz=1C1CHBF_enIN947IN947&oq=john+pendry&aqs=chrome.0.0i355i512j46i512j0i512l2j46i512j0i15i22i30l3j0i22i30l2.2305j0j7&sourceid=chrome&ie=UTF-8.

NobelPrize.org. “The Nobel Prize in Chemistry 2011.” Accessed September 24, 2023. https://www.nobelprize.org/prizes/chemistry/2011/shechtman/facts/.

“Omar Yaghi – Google Search.” Accessed September 24, 2023. https://www.google.com/search?q=omar+yaghi&rlz=1C1CHBF_enIN947IN947&oq=omar+yaghi&aqs=chrome.0.0i355i512j46i512j0i512l8.5713j0j7&sourceid=chrome&ie=UTF-8.

PROFESSOR SIR MICHAEL VICTOR BERRY, FRS. “PROFESSOR SIR MICHAEL VICTOR BERRY, FRS.” Accessed September 24, 2023. https://michaelberryphysics.wordpress.com/.

“Sajeev John – Google Search.” Accessed September 24, 2023. https://www.google.com/search?q=sajeev+john&rlz=1C1CHBF_enIN947IN947&oq=sajeev+john&aqs=chrome.0.0i355i512j46i512j0i512l2j0i22i30l3j0i390i650.2812j0j7&sourceid=chrome&ie=UTF-8.