From Lahore to the Stars: The Genius of Subrahmanyan Chandrasekhar

In the autumn of 1983, browsing through a university bookshop, I stumbled upon ‘An Introduction to the Study of Stellar Structure’ by S. Chandrasekhar. The name rolled off my tongue with intrigue. Little did I know that just months later, the man behind the name, Subrahmanyan Chandrasekhar, would win the Nobel Prize for the insightful mathematics he done in 1930 — at the tender age of 19, while sailing from India to England to take up a scholarship at the University of Cambridge. His revolutionary discovery would forever change our understanding of the cosmos, even if it took the world many years to catch up with his brilliance.

Born on October 19, 1910 in Lahore to a family of Shaivite Brahmans, Chandra was a precocious if mischievous child. Tutored at home as his father distrusted the quality of the local schools – his mother taught him Tamil, his father English and mathematics – he did not enter formal schooling until he was eleven. By the time he was 15, at the Presidency College in Chennai, he was considered a maths prodigy. He was so devoted to his studies that his father used to admonish him, telling him to stop reading so much and get some fresh air. Then, at the age of 17, he spent the summer working in Kolkata, at his uncle’s laboratory, where he broke some of the apparatus, confirming for him that he was not destined to be an experimentalist. That uncle of his was C.V. Raman, famous for his work in the physics of light scattering, winner of the Nobel Prize in 1930, the first non-White person to do so in any branch of the sciences.

It was in his uncle’s laboratory that Chandra was introduced to the mathematics of the new quantum mechanics that was then transforming the world of physics, actually meeting such eminences as Arnold Sommerfeld and Werner Heisenberg. In 1929, with the help of Ralph Howard Fowler, Chandra published his first paper in the Proceedings of the Royal Society.

Fowler was to transform Chandra’s life. Fowler had been thinking about white dwarfs – small, hot, and very dense remnants of stars that have burned through all their nuclear fuel. Such stellar remnants did not make sense. Such stars should undergo total gravitational collapse. But, by applying the new quantum mechanics to white dwarfs, Fowler solved the problem of their existence.

On his voyage to England to become Fowler’s doctoral pupil at Cambridge, Chandra turned his mind to Fowler’s work on white dwarfs. Chandra’s insight was to realise that special relativistic effects must be taken into account within a white dwarf. Working out the mathematics, he demonstrated that Fowler’s explanation of the physics that stabilized white dwarfs would be true only up to a point, that there was an upper limit – now known as the Chandrasekhar Limit – to the mass of a star that could evolve into a white dwarf, about 1.4 times the mass of our sun. Any greater and the star would collapse into what we now know as a neutron star or even a black hole. Chandra’s insight has to be one of the greatest scientific discoveries of the 20th century.

However, at Cambridge, Chandra’s work on white dwarfs was to be ignored. As he completed his doctorate, he refined his calculations, and was pleasantly surprised when the great astronomer Sir Arthur Stanley Eddington, arranged for him to speak in 1935 at the Royal Astronomical Society in London. Expecting Eddington to support him, Chandra was shocked when Eddington spoke after him, ridiculing his conclusions, stating that something as large as a star could not simply disappear. Such was Eddington’s formidable prestige it would take many years for the Chandrasekhar Limit to be accepted. And it was not until 1972, when the first black hole, Cygnus X-1, was identified, that Chandra and his work would be fully vindicated.

Deciding that any future career path in England was now blighted by Eddington, Chandra returned briefly to India in 1936, where he married Lalitha, a physics scholar herself. It was a rare love match in those days. They would share a passion for literature and classical music. Unhappy with the political situation in India, Chandra and Lalitha left for the United States where he took up a position at the University of Chicago. There, he would stay for the rest of his working life, conducting much more ground-breaking research, and achieving fame as both an inspiring and intimidating teacher.

Although his Nobel Prize in 1983 was awarded solely for his youthful discovery, Chandra’s contributions to astrophysics spanned decades of groundbreaking work. Perhaps feeling the sting of the long-delayed recognition, he ended his Nobel lecture with a poignant reflection:

“The simple is the seal of the true. And beauty is the splendour of truth.”

(The writer is a novelist and retired investigator with an abiding passion for Chinese history)