VISMAYA: History & Philosophy of Physics

Tag: physics

  • Conversation with Ashutosh Jogalekar

    Ashutosh Jogalekar is a scientist, science writer, and historian of science based in the San Francisco Bay Area. He develops agentic AI frameworks for science at Microsoft and is a Scientist in Residence at the Oppenheimer Project, where he studies emerging technology risks. Trained as a chemist, his interests span artificial intelligence, biotechnology, drug discovery, the history and philosophy of science, and U.S. history. He is also the author of the long-running Curious Wavefunction blog and has written for Nature, Scientific American, Fast Company, and the Lindau Meeting of Nobel Laureates.

    In this episode, we discuss his work, writings, various interests and his friendship and interaction with Freeman Dyson and many others.

    References:

    The Curious Wavefunction. n.d. Accessed 11 July 2026. http://wavefunction.fieldofscience.com/.

    X (Formerly Twitter). ‘Ash Jogalekar (@curiouswavefn) / X’. 9 July 2026. https://x.com/curiouswavefn.

    ‘Ash Jogalekar | LinkedIn’. Accessed 11 July 2026. https://www.linkedin.com/in/ash-jogalekar-0649934/.

    Jogalekar, Ash. ‘The Curious Wavefunction | Ash Jogalekar | Substack’. 15 June 2026. https://medchemash.substack.com/.

    ‘Ash Jogalekar’. Bulletin of the Atomic Scientists, n.d. Accessed 11 July 2026. https://thebulletin.org/biography/ash-jogalekar/.

    ‘Ashutosh Jogalekar – 3 Quarks Daily’. Accessed 11 July 2026. https://3quarksdaily.com/3quarksdaily/author/ashutoshjogalekar.

    ‘‪Ashutosh Jogalekar‬ – ‪Google Scholar‬’. Accessed 11 July 2026. https://scholar.google.com/citations?user=voMehLQAAAAJ&hl=en.

    Scientific American. ‘Stories by Ashutosh Jogalekar’. Accessed 11 July 2026. https://www.scientificamerican.com/author/ashutosh-jogalekar/.

  • Criticism – just a science thing..

    Conclusion of a review paper:

    Reference:

    Beyer, Robert T. ‘Radiation Pressure—the History of a Mislabeled Tensor’. The Journal of the Acoustical Society of America 63, no. 4 (1978): 1025–30. https://doi.org/10.1121/1.381833.

  • The 5 Maxwellians

    One of the underappreciated facts is the amount of work that people did to bring Maxwell’s theory of electromagnetism to the form that we use today. Among many enthusiastic researchers, five names often come into the picture, and they are Poynting, Heaviside, Fitzgerald, Lodge, and Hertz. Without their contribution, we would have been seeing a very different form of Maxwell’s electromagnetic theory and the equations named after Maxwell. As Loudon and Baxter describe: “The main influence on all of the activity in electromagnetic theory during the later years of the nineteenth century came from Maxwell’s famous treatise (Maxwell 1873). Poynting was a member of the group of young physicists led by Heaviside, Fitzgerald, Lodge and Hertz who developed Maxwell’s electromagnetic theory in the years following his death in 1879. They transformed his 1873 presentation into the formalism recognizable today as Maxwell’s equations.” (Loudon and Baxter, 2012, p. 1826)

    Interestingly, all five Maxwellians were not only interested in electromagnetic field theory but also applied it to a variety of practical problems. Poynting wrote an elaborate paper in which he describes the transfer of energy and momentum of electromagnetic waves titled “On the Transfer of Energy in the Electromagnetic Field” (Poynting, 1884, p. 343), and connected them to a series of interesting observations in electromagnetism. Among the seven applications Poynting discussed in his paper, the last one was on the theory of electromagnetic waves, and it is there that he computed the maximum value of the velocity of light. More on this in a future blog.

    References:

    Loudon, R., and C. Baxter. ‘Contributions of John Henry Poynting to the Understanding of Radiation Pressure’. Proceedings of the Royal Society A: Mathematical, Physical and Engineering Sciences 468, no. 2143 (2012): 1825–38. https://doi.org/10.1098/rspa.2011.0573.

    Poynting, J. H. ‘XV. On the Transfer of Energy in the Electromagnetic Field’. Philosophical Transactions of the Royal Society of London, no. 175 (December 1884): 343–61. https://doi.org/10.1098/rstl.1884.0016.

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  • Bohr’s handwriting

    Niels Bohr had an interesting handwriting, and below is a gist as described by Pais1

    1. Pais, Abraham. 1991. Niels Bohr’s Times: In Physics, Philosophy, and Polity. Oxford Univ Pr. p. 10.
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  • Unified subject map of physics – 130 years

    An interesting paper on arxiv today, which charts the “disciplinary evolution of 130 years of physics”

    Nguyen, Khoa, Pragyan Pandey, Sophie Li, and Eric Y. Ma. ‘A Unified Subject Map for 130 Years of Physics’. arXiv:2606.14043. Preprint, arXiv, 12 June 2026. https://doi.org/10.48550/arXiv.2606.14043.

  • Conversation with Ashna Bajpai

    Ashna is an associate professor of physics at IISER, Pune, with research interests in experimental low-temperature physics that include magnetic oxides, carbon nanotubes, and spintronics.

    In this episode, we explored her explorations in condensed matter and nanophysics. Also, we converse about Prof. R. Srinivasan, a remarkable experimental physicist who pioneered cryogenics and teaches it to college students and researchers across India.

    Explore her work here:

  • lab –> www

    A lab is a place where questions are asked, experiments are conducted, and theories are tested…& sometimes.. in this pursuit, the world is changed.

    A case in point is the connection between CERN and the origins of www :

    https://home.cern/science/computing/the-birth-of-the-web

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  • Tiny value of the radiation pressure of sunlight on Earth

     

    • If radiation pressure is indeed a genuine electromagnetic phenomenon, then why don’t we observe it in our everyday lives?
    • The reason is that the magnitude of the radiation pressure from the natural light source on Earth (the Sun) is feeble.
    • from electromagnetic theory, this tiny amount of pressure can be calculated by the formula \(\frac{E}{c}\), where ‘E’ is the energy of sunlight on earth and ‘c’ is the speed of light in vaccum (which is \(3 \times 10^8 \text{ ms}^{-1}\) [\(9.83 \times 10^8 \text{ ft s}^{-1}\)]).
    • Maxwell himself recognized the low value of this energy, which he assumed to be \(83.4 \frac{\text{ft} \cdot \text{pound}}{\text{sec} \cdot (\text{ft})^2}\)
    • Taking this value and dividing it by ‘c’ gives us a radiation pressure of \(10^{-7} \frac{\text{pound}}{(\text{ft})^2}\).
    • Poynting, who extensively worked on radiation pressure from an electromagnetic theory viewpoint, compared this tiny pressure to the size of a grain in an area of \(200,0000 \text{ (ft)}^2\)!
    • This highlights why radiation pressure is hard to measure experimentally, and it took some trial and error to ascertain the value and the method. More on this later…

    Reference :

    Loudon, R., and C. Baxter. ‘Contributions of John Henry Poynting to the Understanding of Radiation Pressure’. Proceedings of the Royal Society A: Mathematical, Physical and Engineering Sciences 468, no. 2143 (2012): 1825–38. https://doi.org/10.1098/rspa.2011.0573.

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  • Conversation with Prasad Subramanian

    Prasad Subramanian is a Professor at the Indian Institute of Science Education and Research Pune whose research spans plasma astrophysics, solar physics, and space weather. His work focuses on solar coronal mass ejections, black hole accretion, and astrophysical jets, combining theoretical approaches with observational data. He has contributed significantly to understanding turbulence, magnetic fields, and energetic processes in cosmic plasmas. He is also actively involved in science communication and interdisciplinary academic initiatives.

    In this conversation, we discuss general aspects of astrophysics and the research topics he is interested in.

    References with links:

    ‘Prasad Subramanian’. Accessed 21 May 2026. https://sites.iiserpune.ac.in/~p.subramanian/.

    ‘Prasad Subramanian – IISER Pune’. Accessed 21 May 2026. https://www.iiserpune.ac.in/research/department/physics/people/faculty/regular-faculty/prasad-subramanian/343.

    ‘‪Prasad Subramanian‬ – ‪Google Scholar‬’. Accessed 21 May 2026. https://scholar.google.co.in/citations?user=EHu_h-kAAAAJ&hl=en.

    ‘Nptel.Ac.in/Courses/115106124’. Accessed 21 May 2026. https://nptel.ac.in/courses/115106124.

  • When Chandra’s paper got rejected

    Sometimes, referee reports can be frustrating, especially if your paper gets rejected and criticized without justification. This is not a new thing in scientific discourse, and even accomplished researchers like S. Chandrasekhar had to face such rejections. As Chandra notes in the winter of 1956:

    “The frustration of these months was due also to the fact that the Royal Society rejected my second paper on turbulence with a most discourteous referee’s report. I withdrew the paper, but continued the correspondence with the referee. The referee withdrew some of his more blatant remarks; but the whole incident was an unhappy interlude. I went specially to Washington to talk to von Neumann; and corresponded also with Heisenberg.” (Chandrasekhar, 2010, p. 38)

    When a paper gets rejected, what is important is to seek feedback from people who are knowledgeable and courteous. Chandra had friends such as von Neumann and Heisenberg to seek input. One cannot get better than this.  

    Source:  Chandrasekhar, S. 2010. A Scientific Autobiography: S. Chandrasekhar: With Selected Correspondence. (posthumously published)