Greatest Scientists of the 20th century Mr Subrahmanyan Chandrasekhar

The inventor of Chandrasekhar Limit, Mr Subrahmanyan Chandrasekhar was Novel Prise Winner for Physics in 1983  

One of the greatest scientists of the 20th century Mr Subrahmanyan Chandrasekhar, an Indian by birth and American by citizenship was astrophysicist and mathematician who won Nobel Prize for Physics in 1983 for theoretical studies of the physical processes about THE STRUCTURE AND EVOLUTION OF THE STARS. He also talked on evolutionary stages of massive stars and black holes in his mathematical studies. He had given the concept of famous CHANDRASEKHAR LIMIT which has been named after him because of his hypothesis and proposed theory on it. The CHANDRASEKHAR LIMIT is the maximum mass of a stable white dwarf star. The white dwarf star obtaining masses more than the limit goes on further gravitational collapse, converting into various stellar remnants, such as a neutron star or black hole.

Mr Subrahmanyan Chandrasekhar was born on 19 October 1910 at Lahore, Punjab (presently in Pakistan) in British India. He was belonging to a Tamil Brahmin family and his early study was happened at home itself where his father and mother used to teach him. Till his middle school study he was taught by his father and mother. His father taught him Mathematics and Physics while his mother taught him Tamil. He was very much inspired by Ramanujan’s example of total dedication to science and his interest in Ramanujan remained to his entire life. Chandrasekhar married to Lalitha Dorai swamy in September 1936 who was a fellow student at Presidency College. He got U.S. citizenship in 1953.

His mother Late Smt Sita Balakrishnan (1891–1931) and his father Late Mr Chandrasekhar Subrahmanyan Ayyar (1885–1960) were also intellectual persons. Mr Ayyar was DAG of North-Western Railways posted in Lahore and his mother was literary intellectual who had translated Henrik Ibsen’s book ‘A Doll’s House’ in Tamil. She was the leady who had aroused the intellectual curiosity in Mr Chandrasekhar. When Mr Chandrasekhar was born, his father was posted at Lahore who six years later moved to Allahabad in 1916, and finally settled in Madras in 1918.

Chandrasekhar completed his school education from Hindu High School in Madras and obtained his degree of BSc (Hon) in 1930 from Presidency College, Madras (now Chennai). He wrote his first paper, “The Compton Scattering and the New Statistics”, in 1929 before completing his Bachelor of Science Honours. He went to University of Cambridge for higher study on scholarship offered by the Government of India. He met with R. H. Fowler (his mentor during his research) in the Trinity College in Cambridge and discussed about his first paper with him. Chandrasekhar was already working out to Fowler’s previous work for the statistical mechanics of the degenerated electron gas in white dwarf stars. He provided relative corrections the work during his tour to England.

He served the University of Chicago as a professor for long time from 1937 until his death in 1995 at the age of 84. He was the Morton D. Hull Distinguished Service Professor of Theoretical Astrophysics. He did some of his studies at the Yerkes Observatory also and served as an editor of The Astrophysical Journal for over 19 years from 1952 to 1971. He worked on numerous physical problems contributing to understanding the study of stellar structure with his concept like white dwarfs, stellar dynamics (the systems of many point mass particles whose mutual gravitational interactions determine their orbits.), stochastic process (in probability theory and related fields, a stochastic (or random) process is a mathematical object usually defined as a family of random variables).

Besides, the study of radioactive transfer (the physical phenomenon of energy transfer in the form of electromagnetic radiation), the quantum theory (the theoretical basis of modern physics that explains the nature and behaviour of matter and energy on the atomic and subatomic level), hydrodynamic (a branch of physics that study motion of fluids and its forces applied on solid bodies immersed in it and in relative motion to them ) and hydro magnetic stability, turbulence (fluid motion characterized by chaotic changes in pressure and flow velocity), equilibrium, general relativity, mathematical theory of black holes and theory of colliding gravitational waves, etc are also to his credit.

At the University of Cambridge he defined that the mass of a white dwarf con not exceed 1.44 times that of the Sun – the Chandrasekhar limit. He revised the models of stellar dynamics which was first outlined by Jan Oort and many other scientists on the basis of the effects of variable gravitational fields on stars. His solution to this complex problem was “dynamical friction” that was described new quantity which has the dual effects of decelerating the star and helping to stabilize clusters of stars. Chandrasekhar extended this analysis further to the interstellar medium, showing that clouds of galactic gas and dust are distributed much unevenly.

There are numerous awards, accolades and recognition to his name which included: FRS in 1944;  Adams Prize in 1948; Nobel Prize in Physics in 1983; Copley Medal in 1984, National Medal of Science in 1966; Royal Medal in 1962; Padma Vibhushan in 1968 and Heineman Prize in 1974. Mr Chandrasekhar worked on a project which was devoted to explaining the detailed geometric arguments in Sir Isaac Newton’s book “Philosophiae Naturalis Principia Mathematica” using the language and methods of ordinary calculus. His work and effort was published in the book “Newton’s Principia for the Common Reader” in 1995. Chandrasekhar was an honorary member of the International Academy of Science.

Many people considered him positive minded, generous, and open hearted in various debates, while many people criticised him also for his work especially to non-scientific matters. His thought was different and modern. There was an incident when once he was involved in a discussion about the Gita, and said, “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.” This was also confirmed many times in his other talks and various interviews.

Mr Chandrasekhar mostly lived and worked abroad. However, he was deeply concerned with India’s well-being and was associated with many scientific institutions and young Indian scientists. He played considerably deciding and an instrumental role in establishing the Ramanujan Institute of Mathematics (RIMs) in Madras in the late 1940s. When the Institute was facing financial crisis he helped it reviving it financially by taking up the matter to then leading politicians. He also managed to get increased pension for Ramanujan’s widow who was living in poverty.

Mr Chandrasekhar died of heart attack at the University of Chicago Hospital in 21 August 1995, it was the second heart attack for him which turned fatal. Before that he was once survived of heart attack in 1975. His wife died on 2 September 2013 at the age of 102.