Subrahmanyan Chandrasekhar

Chicago, US

1930–7

Subrahmanyan Chandrasekhar was an applied mathematician and astrophysicist. He completed his university education at Presidency College, Madras, graduating with a Bachelor of Science degree in physics. In June 1930 he moved to Britain for postgraduate studies. He was awarded a Government of India scholarship to study at Cambridge as a member of Trinity College, where he became a research student under the supervision of Professor R. H. Fowler. He took his PhD degree at Cambridge in the summer of 1933. In October 1933 he was awarded a Prize Fellowship at Trinity College for the period 1933–7. He joined the faculty of the University of Chicago in 1937 and remained there for the rest of his academic career.

He made one of his most significant discoveries, called ‘Chandrasekhar's limit’, while on his way to England. He applied Einstein’s theory of relativity to the processes inside a star. His calculations suggested that once a star had burned up all its energy it would collapse to a point of infinite density, until it disappeared in what would be later described as a black hole. On his arrival in Cambridge, however, his colleagues paid little attention to his discovery. Arthur Eddington took great interest in Chandrasekhar’s work, and it looked as though he approved of his work. He persuaded Chandrasekhar to present his findings at the Royal Astronomical Society in London on 11 January 1935. The day before the event, he found out that Eddington would give the following lecture on the same topic. Eddington used the opportunity to demolish the young researcher’s calculations and theory, dismissing them as mere mathematical game-playing. However, while Chandrasekhar’s work was based on sound mathematical calculations, Eddington’s argument was in this case unfounded.

It would take years before scientists would follow up Chandrasekhar’s calculations and the controversy would preoccupy scientific journals for several years. In 1966 scientists combined computer codes for astrophysics and the hydrogen bomb and proved that a star could collapse and fall into a black hole. In 1972 the first black hole was positively identified. Chandrasekhar's outstanding contribution to astrophysics was acknowledged with the 1983 Nobel Prize in Physics for his work on white dwarfs and black holes and in 1984 by the Royal Society's Copley Medal.