Below are two quotes on the blackboard of Feynman’s office in Caltech which were found just after his death.
Category: History
Physics Ideas for Entrepreneurs
Starting a new (ad)venture
A YouTube channel dedicated to discussing physics ideas for entrepreneurs
I bring ideas from an ocean of physics and present them to anyone interested in using them for business and entrepreneurship. These are not physics lectures, but discussions on ideas with a perspective of economic utility.
As with all my ventures, it is open source.
Join me in this journey, and please share and subscribe
The first video is out:
Raman essay and Open-Access
I see that the essay I wrote on CV Raman and made open access (thanks to Resonance, which published it) has been used by several educators on YouTube, including some in Indian languages. Also, the Google AI overview shows the published essay as the main reference for a search related to Raman’s science communication (see slideshow below).
I am glad to see that making one’s writing open to all has positive effects. Open-access, not just for readers, but also for authors, is beneficial. Especially in India, paywalls for science are a detriment.
My worry is that open-access publishing has been mainly driven by commercial publishers that extract huge funds from the publishing authors. This defeats the purpose of open science, especially when the research of an author is publicly funded. Added to that, Indian researchers and writers cannot afford to pay huge sums for publishing articles and books.
The publication landscape (including journals and books) across the world needs an introspection. Open-access model is effective only when the readers and authors have access to that model. Otherwise, the model becomes a paywall for authors.
Quantum Optics – teaching in Jan 2026
More than 22 years ago, I started my journey as a research student in theoretical physics – Quantum Electrodynamics (QED) + Radiative Transfer (MSc summer project at the Indian Institute of Astrophysics), and my special paper in the MSc final semester was QED. Later in my PhD, I branched into experiments on light scattering (Raman, Mie & Rayleigh).
Over the years, QED and quantum optics have always been at the back of my mind while studying, researching and teaching.
Come January, I will be teaching a course on Quantum Optics to MS(Quantum Tech), MS-PhDs, and 4th-year physics UGs
I designed the first course on this topic at IISER Pune about a decade ago with the able inputs from Prof. Rajaram Nityananda, and I have taught the course a few times. Now, after a few years, I will teach it again.
With the emergence of quantum sci & tech, there is a new impetus and excitement on this topic.
Having said that, the foundations of the topic remain the same, and Quantum Optics has a wonderful history and philosophy associated with it…and where better to start than Dirac’s classic (see below).
Look out for ‘quantum blogs’ in 2026…

Betty Archdale – 1939 cricket picture – Kannada magazine
This may be a rare pic:

In 1939, a Kannada magazine – Swadeshabhimani – reported on growing interest in women’s cricket.
Pictured is a shot by Betty Archdale, the then women’s cricket captain in England (according to the caption in the picture).
A copy of the magazine can be found here:
https://archive.org/details/karnataka-state-archives-RGVlcGFrMTA0MjYz-RGVlcGFrMQ/page/n23/mode/2up
Humanizing Science – A Conversation with a Student
Recently, I was talking to a college student who had read some of my blogs. He was interested in knowing what it means to humanize science. I told him that there are at least three aspects to it.
First is to bring out the wonder and curiosity in a human being in the pursuit of science. The second was to emphasize human qualities such as compassion, effort, mistakes, wrong directions, greed, competition and humour in the pursuit of science. The third thing was to bring out the utilitarian perspective.
The student was able to understand the first two points but wondered why utility was important in the pursuit of humanizing science. I mentioned that the origins of curiosity and various human tendencies can also be intertwined with the ability to use ideas. Some of the great discoveries and inventions, including those in the so-called “pure science” categories, have happened in the process of addressing a question that had its origin in some form of an application.
Some of the remarkable ideas in science have emerged in the process of applying another idea. Two great examples came into my mind: the invention of LASERs, and pasteurization.
I mentioned that economics has had a major role in influencing human ideas – directly or indirectly. As we conversed, I told the student that there is sometimes a tendency among young people who are motivated to do science to look down upon ideas that may have application and utility. I said that this needs a change in the mindset, and one way to do so is to study the history, philosophy and economics of science. I said that there are umpteen examples in history where applications have led to great ideas, both experimental and theoretical in nature, including mathematics.
Further, the student asked me for a few references, and I suggested a few sources. Specifically, I quoted to him what Einstein had said:
“….So many people today—and even professional scientists—seem to me like someone who has seen thousands of trees but has never seen a forest. A knowledge of the historic and philosophical background gives that kind of independence from prejudices of his generation from which most scientists are suffering. This independence created by philosophical insight is—in my opinion—the mark of distinction between a mere artisan or specialist and a real seeker after truth..”
The student was pleasantly surprised and asked me how this is connected to economics. I mentioned that physicists like Marie Curie, Einstein and Feynman did think of applications and referred to the famous lecture by Feynman titled “There is Plenty of Room at the Bottom” (1959).
To give a gist of his thinking, I showed what Feynman had to say on miniaturization:
“There may even be an economic point to this business of making things very small. Let me remind you of some of the problems of computing machines. In computers we have to store an enormous amount of information. The kind of writing that I was mentioning before, in which I had everything down as a distribution of metal, is permanent. Much more interesting to a computer is a way of writing, erasing, and writing something else. (This is usually because we don’t want to waste the material on which we have just written. Yet if we could write it in a very small space, it wouldn’t make any difference; it could just be thrown away after it was read. It doesn’t cost very much for the material).”
I mentioned that this line of thinking on minaturization is now a major area of physics and has reached the quantum limit. The student was excited and left after noting the references.
On reflecting on the conversation, now I think that there is plenty of room to humanize science.
Why is astronomy interesting? Chandra likes Wigner’s answer
The questions “Why is astronomy interesting; and what is the case for astronomy?” have intrigued me; I have often discussed these questions with my friends and associates. Granted that physical science, as a whole, is worth pursuing, the question is what the particular case for astronomy is? My own answer has been this: Physical science deals with the entire range of natural phenomena; and nature exhibits different patterns at different levels; and the patterns of the largest scales are those of astronomy. (Thus Jeans’ criterion of gravitational instability is something which we cannot experience except when the scale is astronomical.) Of the many other answers to my questions, I find the following of Wigner most profound: “The study of laboratory physics can only tell us what the basic laws of nature are; only astronomy can tell us what the initial conditions for those laws are.”
from A Scientific Autobiography: S. Chandrasekhar (2011) by edited by Kameshwar C. Wali
Polanyi’s quote
“…The example of great scientists is the light which guides all workers in science, but we must guard against being blinded by it. There has been too much talk about the flash of discovery and this has tended to obscure the fact that discoveries, however great, can only give effect to some intrinsic potentiality of the intellectual situation in which scientists find themselves…”
Michael Polanyi, in an essay titled “My Time with X-Rays and Crystals” (1969)
Random Walks in Polarization
I have been teaching polarization of light in my optics class. In there, I introduced them to matrix representation of polarization states. One of the standard references that I use for explanation is a 1954 paper in American J. Physics, by McMaster titled: “Polarization and the Stokes Parameters.”
While skimming through the pdf of the journal paper, I found an excerpt from a 1954 book, which quotes Fresnel writing to Thomas Young:

Further, I knew from the past that S. Chandrasekhar (astrophysicist) had a role in rejuvenating Stokes vector formalism in radiative transfer. Below is his description from AIP oral history archives (May 1977):
” I started the sequence of papers, and almost at the time I started it, I read the paper by Wick in which he had used the method of discrete coordinates,* and I realized at once that that method can be used in a large scale way for solving all problems. So that went on. I have always said and felt that the five years in which I worked on radiative transfer [1944 – 49] is the happiest period of my scientific life. I started on it with no idea that one paper would lead to another, which would lead to another, which would lead to another and soon for some 24 papers — and the whole subject moved with its own momentum.” (emphasis added)
He further states how he rediscovered Stokes polarization vector formalism:
“All this had a momentum of it own. Then suddenly I realized one had to put polarization in; the problems of characterizing polarized light — my rediscovery of Stokes original paper, writing on Stokes parameters and calling them Stokes parameters for the first time“
Chandra further adds that the Stokes formalism was almost forgotten for 50 years, and he had a role in resurrecting it.

Next, there was some noise on social media where some one questioned the utility of matrix multiplication. For them, below is a wonderful review article by McMaster (again), to explore from polarization viewpoint, and realize the power of non-commutative matrix algebra:

Finally, the original paper by Stokes on his formalism, which is hard to find (thanks to paywall). But, classic papers are hard to suppress, and I found the full paper on internet archives.
Below is a snapshot:

Enjoy your random walk !
Cartoon – Factory Workers

A cartoon from a 1947 edition of a US magazine
Source: https://archive.org/details/sim_factory_1947-08_105/page/112/mode/1up

