Padma Vibhushan Subrahmanyan Chandrasekhar, FRS (Tamil: சுப்பிரமணியன் சந்திரசேகர்), English ) (October 19, 1910 – August 21, 1995) was an Indian born American astrophysicist, and Nobel laureate in physics along with William Alfred Fowler for their work in the theoretical structure and evolution of stars.

Chandrasekhar served on the University of Chicago faculty from 1937 until his death in 1995 at the age of 84. He became a naturalized citizen of the United States in 1953.

Biography

Chandrasekhar was born in Punjab Lahore, British India (Present day Pakistan), into an Iyer family, the third of ten children to Sita Balakrishnan, and Subrahmanya Ayyar, a senior officer in the Indian Audits and Accounts Department. Subrahmanya Ayyar was posted in Lahore as the Deputy Auditor General of the Northwestern Railways at the time of Chandrasekhar's birth.

Chandra's father was also an accomplished Carnatic music violinist who had authored several books on musicology. His mother was devoted to intellectual pursuits and had translated Henrik Ibsen's A Doll's House into Tamil. She is credited with arousing Chandra's intellectual curiosity early on. Chandra's father's brother, physicist C. V. Raman is also a Nobel laureate in physics.

Chandra was tutored at home initially through middle school and later attended the Hindu High School, Triplicane, Madras, British India during the years 1922-25. Subsequently, he studied at Presidency College from 1925 to 1930, obtaining his bachelor's degree, B.Sc. (Hon.), in physics in June 1930. In July 1930, Chandrasekhar was awarded a Government of India scholarship to pursue graduate studies at the University of Cambridge, where he was admitted to Trinity College and became a research student of Professor R. H. Fowler. On the advice of Prof. P. A. M. Dirac, as part of his graduate studies, Chandra spent a year at the Institut for Teoretisk Fysik in Copenhagen, where he met Prof. Niels Bohr.

In the summer of 1933, Chandrasekhar was awarded his Ph.D. degree at Cambridge, and the following October, he was elected to a Prize Fellowship at Trinity College for the period 1933-37. During this time, he made acquaintances with Sir Arthur Eddington and Professor E. A. Milne.

In September 1936, Chandrasekhar married Lalitha Doraiswamy, who he had met as a fellow student at Presidency College, Madras, and who was a year junior to him. In his Nobel autobiography, Chandrasekhar wrote, "Lalitha's patient understanding, support, and encouragement have been the central facts of my life."

Career

The following year in January 1937, Chandrasekhar was recruited to the University of Chicago faculty as Assistant Professor by Dr. Otto Struve and President Robert Maynard Hutchins. He was to remain at the university for his entire career, becoming Morton D. Hull Distinguished Service Professor of Theoretical Astrophysics in 1952 and attaining emeritus status in 1985.

During World War II, Chandrasekhar worked at the Ballistic Research Laboratories at the Aberdeen Proving Ground in Maryland. While there, he worked on problems of ballistics; for example, two reports from 1943 were titled, On the decay of plane shock waves and The normal reflection of a blast wave.

Chandrasekhar developed a style of working continuously in one specific area of physics for a number of years; consequently, his working life can be divided into distinct periods. He studied stellar structure, including the theory of white dwarfs, during the years 1929 to 1939, and subsequently focused on stellar dynamics from 1939 to 1943. Next, he concentrated on the theory of radiative transfer and the quantum theory of the negative ion of hydrogen from 1943 to 1950. This was followed by sustained work on hydrodynamic and hydromagnetic stability from 1950 to 1961. In the 1960s, he studied the equilibrium and the stability of ellipsoidal figures of equilibrium, but also general relativity. During the period, 1971 to 1983 he studied the mathematical theory of black holes, and, finally, during the late 80s, he worked on the theory of colliding gravitational waves.

During the years 1990 to 1995, Chandrasekhar worked on a project which was devoted to explaining the detailed geometric arguments in Sir Isaac Newton's Philosophiae Naturalis Principia Mathematica using the language and methods of ordinary calculus. The effort resulted in the book Newton's Principia for the Common Reader, published in 1995. Chandrasekhar was an honorary member of the International Academy of Science.

Subrahmanyan Chandrasekhar died of heart failure in Chicago in 1995, and was survived by his wife, Lalitha Chandrasekhar. In the Biographical Memoirs of the Fellows of the Royal Society of London, R. J. Tayler wrote: "Chandrasekhar was a classical applied mathematician whose research was primarily applied in astronomy and whose like will probably never be seen again.

Nobel prize

He was awarded the Nobel Prize in Physics in 1983 for his studies on the physical processes important to the structure and evolution of stars. Chandrasekhar accepted this honor, but was upset that the citation mentioned only his earliest work, seeing it as a denigration of a lifetime's achievement.

Legacy

Chandrasekhar's most famous success was the astrophysical Chandrasekhar limit. The limit describes the maximum mass of a white dwarf star, ~1.44 solar masses, or equivalently, the minimum mass, above which a star will ultimately collapse into a neutron star or black hole (following a supernova). The limit was first calculated by Chandrasekhar in 1930 during his maiden voyage from India to Cambridge, England for his graduate studies.

When Chandra first proposed this limit during his fellowship at Trinity college in the 1930s, it was obstinately opposed by Arthur Eddington and much to Chandra's frustration none of the established physicists in Europe came to his rescue. This episode had a bitter impact on Chandra resulting in his move to the University of Chicago in the United States and in his choice of moving to another research topic. Chandra, however, compiled all his work on the topic of stellar structures into a book for posterity. This also subsequently led to his style of working continuously in one specific area of physics for a number of years and at the end of that period compiling a book on that topic. As a result, Chandra has left us with great expositions on different topics.

In 1999, NASA named the third of its four "Great Observatories'" after Chandrasekhar. This followed a naming contest which attracted 6,000 entries from fifty states and sixty-one countries. The Chandra X-ray Observatory was launched and deployed by Space Shuttle Columbia on July 231999. The name Chandrasekhar is one of the appellations of Shiva meaning "holder of the moon" in Sanskrit and is a common Tamil name.

The Chandrasekhar number, an important dimensionless number of magnetohydrodynamics, is named after him.

The asteroid 1958 Chandra is also named after Chandrasekhar.

Awards

• Fellow of the Royal Society (1944)
• Henry Norris Russell Lectureship (1949)
• Bruce Medal (1952)
• Gold Medal of the Royal Astronomical Society (1953)
• National Medal of Science award by President Lyndon Johnson (1967)
• Padma Vibhushan (1968)
• Henry Draper Medal (1971)
• Nobel Prize in Physics (1983)
• Copley Medal, the highest honour, of the Royal Society (1984)
• Honorary Fellow of the International Academy of Science (1988)

Bibliography

Books by Chandrasekhar :

• Chandrasekhar, S. (1958). An Introduction to the Study of Stellar Structure. New York: Dover.
• Chandrasekhar, S. (2005). Principles of Stellar Dynamics. New York: Dover.
• Chandrasekhar, S. (1960). Radiative Transfer. New York: Dover.
• Chandrasekhar, S. (1975). Plasma Physics. Chicago: The University of Chicago Press.
• Chandrasekhar, S. (1981). Hydrodynamic and Hydromagnetic Stability. New York: Dover.
• Chandrasekhar, S. (1987). Ellipsoidal Figures of Equilibrium. New York: Dover.
• Chandrasekhar, S. (1998). The Mathematical Theory of Black Holes. New York: Oxford University Press.
• Chandrasekhar, S. (1990). Truth and Beauty. Aesthetics and Motivations in Science. Chicago: The University of Chicago Press.
• Chandrasekhar, S. (1995). Newton's Principia for the Common Reader. Oxford: Clarendon Press. Books about Chandrasekhar:
• Miller, Arthur I. (2005). Empire of the Stars: Friendship, Obsession, and Betrayal in the Quest for Black Holes. Boston: Houghton Mifflin.
• Srinivasan, G. (ed.) (1997). From White Dwarfs to Black Holes: The Legacy of S. Chandrasekhar. Chicago: The University of Chicago Press.
• Wali, Kameshwar C. (1991). Chandra: A Biography of S. Chandrasekhar. Chicago: The University of Chicago Press.
• Wali, Kameshwar C. (ed.) (1997). Chandrasekhar: The Man Behind the Legend - Chandra Remembered. London: imperial College Press.

References

External links

• National Academy of Sciences biography
• Harvard's site on Chandrasekhar
• Subrahmanyan Chandrasekhar
• Subrahmanyan Chandrasekhar
• Subramaniam Chandrashekhar
• Bruce Medal page
• Awarding of Bruce Medal: PASP 64 (1952) 55
• Oral History interview transcript with Subrahmanyan Chandrasekhar 17 May 1977, American Institute of Physics, Niels Bohr Library and ArchivesObituaries
• BAAS 28 (1996) 1448
• Obs 116 (1996) 121 comment
• PASP 109 (1997) 73
• QJRAS 37 (1996) 261