Dr Thanu Padmanabhan (1957-2021): In Remembrance

  • Oops!
    Something went wrong.
    Please try again later.
·7-min read
In this article:
  • Oops!
    Something went wrong.
    Please try again later.

Padma Shri recipient, theoretical physicist and cosmologist, Dr Thanu Padmanabhan passed away in Pune on Friday, 17 September.

Here is a recollection of the scholar's life and works and his lasting contributions to science.

A dedication in a book can sometimes bring out the innermost yearnings of the author. The book had an interesting title – After the first three minutes – the story of our universe, Cambridge University Press, 1998. Coming two decades and a year after the perennial classic The First Three Minutes, written by physicist Steven Weinberg, this book about the cosmic after-story after the first three minutes had been written by an Indian physicist – Thanu Padmanabhan.

Padmanabhan was with the Inter-University Centre for Astronomy and Astrophysics (IUCCAA) at Pune - one of those institutions that make an Indian proud.

One problem with popular science books is that they make the science look so elegant, beautiful and more importantly simple, that the non-specialist reader becomes vulnerable to the delusion that science is all about exotic speculation. This book was different, in the sense that it combines the best of two worlds – lucid narration with a text-book style explanation. And for an undergraduate student of physics, this book can be the gateway to the challenging mysteries in cosmology.

In the last chapter on open questions, Dr. Padmanabhan brought out the question of aesthetics. Physicists building cosmological models also look for aesthetics in their models and not without reason:

"Theoretical sciences, however, have benefited tremendously from aesthetic considerations, and one should not completely ignore aesthetic aspects of a model, however subjective such criteria can be. It has been generally accepted by scientists that models with fewer parameters and which make predictions are better models." -

But post-1992, models have been ‘quite unpleasing’ on the aesthetic front. Even the conventional cosmological model which Padmanabhan adheres to in the book, ‘predicts a singularity at some finite time in the past’, which ‘is probably the most unaesthetic feature any theory can have!’ But it has explanatory power in terms of observed phenomenon like for example, the microwave background radiation.

One is reminded here, of the argument of Sabine Hossenfelder, as to how aesthetics could actually lead physicists away from truth and Michio Kaku’s partial acceptance and rejection of this stand. But that would be again two decades later.

He also co-authored with his wife Vasanti Padmanabhan, also an astro-physicist, a book on the history of science: The Dawn of Science: Glimpses from History for the Curious Mind (Springer, 2019).

This book provides an excellent walk through the history of science in a non-Eurocentric way. It also highlights Indian achievements. There are no exaggerations and the book makes the reader realise how science is a common heritage that unites all humanity, even as it respects cultural diversity. There is no aversion-filled rhetorical claim, like ‘the West stole calculus’ etc. Instead, there is a detailed explanation of what actually the Kerala school of mathematics achieved. Here is an excerpt:

"The word used for the infinitesimal by Madhava, the Indian mathematician who developed these ideas in the fourteenth century, is ‘sunya-prayam’. It is a Malayalam word meaning ‘like zero’, ‘of the size of zero’, etc. The fact that you can make the interval as close to zero as you like is captured by the use of the word ‘yadhestam’, which roughly translates to ‘as you desire’. Once Madhava had the concept of infinitesimal, he could build the rest of the concepts in his own tradition. … Madhava also developed the concept of integration in his tradition of mathematics. Centuries later, the same ideas were developed in greater generality by Leibnitz and Newton." -

This book forms a narrative of the evolution of various sciences. It is also modular – that is, each ‘module’ can be read independently. There are box items which highlight the important points. All this make it a must-read for every lover of science-history as well as every student of Indian history.

'History of science' is a neglected area in our teaching of history. It will be really a tribute to the physicist if this book is used by NCERT in developing its curriculum.

Dr. Padmanabhan also had a philosophical bend of mind laced with humour. His essay on the Bhagavad-Gita is a must read. It is available online on his official IUCAA website. The article is powerful. But if one is either the left-woke or trad-woke, then this article is PG-rated and better not read. But read it if you want to know how a hardcore no-nonsense physicist can approach the Gita, even if he were a non-believer, with reverential intensity.

Consider just these excerpts:

"Incidentally, one direct consequence of this is that authors of Gita or Upanishads do not try to save your souls! There is a clear injunction in verse 18-67 that “Gita should not be conveyed to those who do not wish to hear it”. ... Such an attitude goes hand in hand with the acceptance of all other human endeavors towards happiness — including all other religions — because you have the right to believe that some other religion (e.g., Marxist Socialism or Jainism, it doesn’t matter what you choose!) will solve your problems of unhappiness. Krishna does not quarrel with you. ... Such a liberal and tolerant attitude can only arise in a philosophical structure which is supremely self-confident about its own veracity and mature in its attitude. It knows that, eventually, its tenets have to be accepted and is willing to wait patiently! More diffident and insecure philosophical ideas will resort to force or inducements for their sustenance and propagation." -

One wonders what a great social scientist the astrophysicist would have made. He points out a core Gita vision: at once the basic urge in all religious movements (and note he includes Marxism in that) comes from a need to achieve happiness and if genuine, even through Marxism you ultimately come to Krishna.

And if you thought that he would gloss over the Personal God aspect of Gita, he is not. He embraces the true nature of Gita with an ease of the movements of a Bharatnatyam dancer:

"Krishna is talking about a God to whom you surrender completely. If you do that, the God will exist for you with as much reality as Bhavadharini existed for Sri Ramakrishna. ... But if your surrender or devotion is less than one hundred percent, God does not exist and what you get out of prayers and pujas is similar to the relief you get by visiting a psychiatrist." -

And then this:

"As I said, there are two parallel themes in Gita and only one of them relies on surrender to the Personal God; if you do not want to do it and think that all this God business is nonsense after ‘reflecting on it fully’, why, surely you can still use what is acceptable to you, and Krishna doesn’t mind. Real Gods don’t feel insecure if you tell them they do not exist." -

The last line defines it: ‘Real Gods don’t feel insecure if you tell them they do not exist.’ That should define the Gods and Goddesses of Sanatana Dharma. Otherwise, in what other culture can you see ‘ninthaa’—scolding and disrespecting with bhakti—become a form of stuti, worship? His essay on Gita definitely is an important classic and should deserve as much respect among Hindus as his science works deserves in the physics community.

And his dedication in his book After the First Three Minutes, reads: ‘to my daughter Hamsa, who thinks I should be playing with her instead of writing such books.’

Today, that daughter is also an astrophysicist. Perhaps she may come out with an updated version of After the First Three Minutes with the latest discoveries and theoretical models – as a befitting tribute to her father whose work and life have made all Indians proud as has his sudden demise made us all deeply sad.

Our goal is to create a safe and engaging place for users to connect over interests and passions. In order to improve our community experience, we are temporarily suspending article commenting