Chandra: An Indian Scientist’s Struggle With Prejudice  

As black holes collided, gravitational waves were born 1.8 billion years ago and they travelled as distortions in the space-time fabric. Those many years ago, a third planet around a yellow star was a site of an interesting phenomenon – evolving a new form of life, the eukaryotes, from the more primitive prokaryotes. But, by the time the gravitational waves would reach this pale blue dot, the planet would have developed a sentient civilisation that would have not only hypothesised the presence of gravitational waves but calculated and constructed instruments to cognise them.

All that happened in the blink of an eye in the cosmic time frame. But what is a very minuscule time period in cosmic time would be millennia for us humans, and in that enduring yet ephemeral passage of time, we have discovered the black holes. And in that discovery is the story of an Indian student, a boy from Triplicane Hindu High School, Madras, who had crossed the seas to enter the portals of one of the greatest centres of learning, Cambridge. There he would encounter both Christian evangelism explicitly and colonial racism subtly but adamantly.

Chandrasekhar would recall how one Father Saldanha, a Christian missionary from Kerala, would slip books into his cabin that characterised Hindu gods as primitive, evil and corrupt. While other Hindu students would fume at the missionary, Chandrasekhar would silently listen to him “more out of politeness than anything else” and yet he “never left him in doubt that he did not share his views”.

But a more decisive blow was dealt after one of the most remarkable discoveries of young Chandrasekhar. By 1930, when he was barely 20, the South Indian boy, having spent just one year pursuing graduate study at Trinity College, Cambridge, had come to the audacious conclusion that challenged the prevailing wisdom on the burning of stars.

Physicist, historian of science and author, Arthur Miller, in his engaging book on Chandrasekhar’s work (Empire of the Stars: Friendship, Obsession and Betrayal in the Quest for Black Holes, 2005) writes: “In ten minutes, sitting in a deckchair overlooking the Arabian Sea, Chandra (as he was universally known) carried out some calculations that augured a disturbing fate for small, dense stars known as white dwarfs.”

Till then, it was considered that once a star’s fusion fuel was over, they would become what are called “white dwarfs”. Further, collapse would be stopped by what is called the exclusion principle – the repulsion between electrons. But Chandra said stars with a mass of at least 1.44 times that of the sun would not just stop at that. Here, gravity would be able to conquer the repulsion and the stars would continue to collapse. Into what? Black holes!

There is of course another possibility. Famous Soviet physicist Lev Landau, who too arrived at a limit similar to that of Chandrasekhar, considered that in that case the stars might become neutron stars, denser and smaller than white dwarfs. Whatever the case, the story of stars with masses 1.44 times and above the solar mass, would not stop at being white dwarfs.

Thus was born the Chandrasekhar limit but not without birth pangs.

Miller explains:

Chandrasekhar’s astrophysics guru at Trinity was Sir Arthur Eddington. He was the chief scientist who in 1919, during the total solar eclipse, had put out the stunning first empirical proof of Einstein’s conceptualisation of gravity as presented in his general theory of relativity. In 1933, Chandrasekhar had completed his doctoral thesis and Eddington had assured the presentation of his most brilliant student’s thesis at Royal Astronomical Society in London in 1935. Already Eddington was working on a theory that aimed to unite quantum mechanics and general theory of relativity.

The day 11 January 1935, which should have been a dream launch for a brilliant career of a genius astrophysicist, turned into a nightmare for the young Indian. Yet Eddington, who “himself had flirted with the idea that a dead star might collapse indefinitely in this manner”, without any warning attacked Chandra’s result with convoluted and flimsy arguments. The event would leave a scar on the young Indian physicist prodigy, who was just 20 at the time. Later, Chandrasekhar would recall that Eddington was the only astrophysicist who, with his “enormous physical insight”, would understand that what Chandra proposed implied black holes. Had Eddington accepted that, “he would have been 40 years ahead of anybody else”.

Miller observes that “despite the flimsiness of Eddington’s arguments, the established scientists had chosen to support him against Chandra, the outsider”. But there were notable exceptions, as a disheartened Chandra wrote letters about his meeting with another famous young Belgian physicist, Léon Rosenfeld, who wrote back to him asking him to “cheer up” and characterised Eddington’s criticism as “fruitless arguments”. Soon, two of the greatest physicists of the time, Niels Bohr and Paul Dirac, would also say the same in favour of Chandrasekhar. When at times Chandra used to brood when he saw any merit in Eddington’s attacks, Rosenfeld did not hesitate to call Eddington’s papers against Chandra “nonsense”.

The main reason was perhaps the fact that Eddington was trying to develop a great synthesis of quantum theory and general theory of relativity, still a holy grail for physicists. The work of this Indian student threatened some of the key components of that work. Still, that does not explain the visceral hostility Eddington exhibited towards Chandra. Because Eddington had encouraged another physicist, Edmund Stoner, who too had been working on the limiting mass of white dwarfs, the same line of theoretical research that Chandra was engaging in. So what could have been the actual reason, asks Miller.

Whatever it was, what Eddington did to Chandra definitely inhibited the advancement of black hole physics by decades. It was only in the 1970s that new mathematical work opened up fresh vistas for the subject. Particularly important was the work of a New Zealand physicist, Roy Kerr, in 1963 on spinning black holes. When Chandra’s attention was drawn to Kerr’s work, he uttered the famous words, which in the history of science have become as important as the words “cosmic religious feeling” said by Albert Einstein. Chandra remarked:

In 1964, two decades after the death of Eddington, rocket flights launched by NASA discovered a powerful source of X-ray emission and identified it as Cygnus X-1. Part of a star system which was 6,000 light years away from earth, it was located in the Milky Way galaxy. Two physicists, Gary Gibbons and the other, the famous Stephen Hawking, said in 1971 that evidence for black holes can be seen in binary star systems. In March that same year at a meeting of the American Astronomical Society, Italian astrophysicist Riccardo Giacconi, who laid the foundations for X-ray astrophysics, proposed that Cygnus X-1 was a black hole. In 1990, Hawking would lose a bet and concede that Cygnus X-1 was indeed a black hole. (Hawking had made the bet as ‘insurance policy’, for his lifelong work had been on black holes. If he lost the bet, his lifelong work actually stands vindicated, whereas if he won it, at least he would have had the satisfaction of winning a bet!)

The supreme irony is that the general theory of relativity, which was first empirically vindicated by Eddington, would again be reasserted in a more spectacular manner by the detection of gravitational waves – which would emanate from colliding black holes – the same black holes which Eddington so viciously attacked.

What happened to Chandrasekhar in Cambridge is not an isolated phenomenon. It had also happened to Jagadish Chandra Bose in 1901 at the Royal Society. A whole century and a decade after biophysicist V A Shepherd would point out that science had vindicated Bose: “In 2011 it is understood that most and perhaps all plant cells are excitable, responding to stimuli such as heat, cold, wounding, touch and changes in extra-cellular osmotic pressure with electric signals.”

Yellapragada Subbarow (1895-1948) discovered ATP (adenosine triphosphate), the biological energy coin, in 1929. He was then a graduate student at Harvard Medical School. He also discovered a host of other biochemical remedies for various diseases. However, he never received full credit for his discovery then because “his PhD supervisor Cyrus Fiske took credit for his work”. George Hitching, a fellow student at Harvard, who went on to share the Nobel prize in physiology for the year 1988, said that “some of the nucleosides isolated by Subbarao had to be rediscovered years later by other workers because Fiske apparently out of jealousy, did not let Subbarao's contributions to see the light of the day” (Krishna R Dronamraju, Popularizing Science: The Life and Work of JBS Haldane, Oxford University Press, 2017).

Chandrasekhar too was robbed in a totally unjustified way of the glory he should have received in his youthful exuberance. Yet, in his inner space, he had a great calm. A declared atheist, he was also well-rooted in Hindu philosophy. And he did use this rootedness to face the challenges in his own life and in his melancholic pursuit of the passion of his life – science. In his conversation with Kamelshwar C Wali, a fellow physicist of Indian origin, who was also his biographer, Chandra confided:

Affirming Wali’s response that “it's almost impossible for anyone to say that he is not a Hindu because of such and such” and that “there is ample room for atheism in the Hindu religion”, Chandrasekhar continued that the (Hindu) “idea that as one grows older one has to develop a sense of detachment has played a positive role” for him.

In 1987, at the Colloquium on Nuclear Policy, Culture and History held at Chicago, there was a session titled ‘An Ethics for Nuclear Policy: The Bhagavad Gita, or Gandhian Non-violence or the Middle Way?’ Chandrasekhar delivered a lecture in that session. He started with a cautionary line: “I should like to preface my remarks with a personal statement in order that my later remarks will not be misunderstood. I consider myself an atheist.”

He continued, and the lecture provides the perfect answer to those even within the academia who, as late as 2000, carrying colonial prejudices, caricatured the Gita as “not a nice book” where “Krishna goads human beings into all sorts of murderous and self-destructive behaviors such as war”.

When one reads this poignant observation by Chandrasekhar, coupled with what he endured in his life, one cannot but feel that this has been the basic philosophy of his life – “to play your own part as well as you can under the circumstance in which you happen to be involved”.

The best affirmation of his attitude towards life comes from perhaps the letter written by his brother Parasu Balakrishnan to Chandrasekhar just one year before the latter’s death. Chandra had written to his brother about a “strange feeling” that all his hard work, when the books have been written and the work has been done, seem not to be his own but some extraneous entities by themselves, separate and different from himself. Balakrishnan replied in his letter dated 8 July 1994:

Then, on 21 August 1995, Dr Chandrasekhar Subrahmanyan chose to live forever in his equations.

Today, on his 107th birth anniversary, as the Google Doodle rekindles the memory of this great scientist, we need also to know what a great, relentless, silent fighter he was and what the invisible reservoirs of his strength of spirit looked like.