Subrahmanyan Chandrasekhar

Subrahmanyan Chandrasekhar
File:Chandrasekhar.gif Subrahmanyan Chandrasekhar
Born	19 October1910 Lahore, (British South Asia), now Pakistan.
Died	21 August1995 Chicago, Illinois, USA
Nationality	American
Alma mater	Presidency College Cambridge
Known for	Chandrasekhar limit
Awards	File:Nobel.svg Nobel Prize in Physics (1983)
Scientific career
Fields	Physicist
Institutions	Cambridge University of Chicago
Doctoral advisor	R.H. Fowler
Doctoral students	Russell Kulsrud Norman Lebovitz Guido Muench-Paniagua Donald Edward Osterbrock

"Chandrasekhar" redirects here. For the film director, see Jay Chandrasekhar. For the Prime Minister of India, see Chandra Shekhar.

Subrahmanyan Chandrasekhar (October 19, 1910, (Lahore, British South Asia, now Pakistan, – August 21, 1995, Chicago, Illinois, United States) was an American astrophysicist born of Tamil heritage in Lahore who was awarded the 1983 Nobel Prize in Physics (shared with William Alfred Fowler) for his theoretical work on the 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.

Early life and Education

Chandrasekhar was the third of ten children born to Sita Ayyar (neé Balakrishnan) and Chandrasekhara Subrahmanya Ayyar, a senior officer in the British Indian Audits and Accounts Department, who was posted in Lahore as the Deputy Auditor General of the Northwestern Railways. Chandrasekhar's mother was devoted to intellectual pursuits and had translated Henrik Ibsen's A Doll House into Tamil. His father was an accomplished Carnatic music violinist who had authored several books on musicology. Chandrasekhar was the nephew of Nobel-prize winning physicist C. V. Raman.

Chandrasekhar attended the Hindu High School, Triplicane, Madras, 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 became a research student of Professor R. H. Fowler, and was admitted to Trinity College. On the advice of Prof. P. A. M. Dirac, Chandrasekhar spent a year at the Institut för Teoretisk Fysik in Copenhagen, where he met Prof. Neils 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 formed friendships 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 (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 ballastics; 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 astrophysics 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.

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, though he was upset that the citation mentioned only his earliest work, seeing this as a denigration of a lifetime's achievement. It is not certain if the Nobel selection committee was at least remotely influenced in formulating this citation by the early criticisms of Sir Arthur Stanley Eddington, another distinguished astrophysicst of his time and a senior to him. His lifetime's achievement may be glimpsed in the footnotes to his Nobel lecture.

Legacy

Chandrasekhar's most famous success was the astrophysical Chandrasekhar limit. The limit describes the maximum mass (~1.44 solar masses) of a white dwarf star, or equivalently, the minimum mass for which a star will ultimately collapse into a neutron star or black hole (following a supernova). The limit was first calculated by Chandrasekhar while on a ship from India to Cambridge, England, where he was to study under the eminent astrophysicist, Sir Ralph Howard Fowler. When Chandrasekhar first proposed his ideas, he was opposed by the British physicist Arthur Eddington, and this may have played a part in his decision to move to the University of Chicago in the United States.

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 23, 1999. The name Chandrasekhar is one of appellations of Shiva meaning "holder of the moon" in Sanskrit and is a common Tamil name.

The asteroid 1958 Chandra is also named after Chandrasekhar.

In 2006, the legendary Detroit electronic music pioneer Gerald Donald, under his Arpanet alias, released a song called "Chandrasekhars Limit". It is on the Inertial Frame LP.

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)
• Henry Draper Medal (1971)
• Nobel Prize in Physics (1983)
• Copley Medal, the highest honour, of the Royal Society (1984)

References

• Chandrasekhar, S. (1998) [1983]. The Mathematical Theory of Black Holes. New York: Oxford University Press. ISBN 0-19-850370-9.
• Miller, Arthur I. (2005). Empire of the Stars: Friendship, Obsession, and Betrayal in the Quest for Black Holes. Boston: Houghton Mifflin. ISBN 0-618-34151-X.
• Wali, Kameshwar C. (1991). Chandra: A Biography of S. Chandrasekhar. Chicago: University of Chicago Press. ISBN 0-226-87054-5.

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

Obituaries

• BAAS 28 (1996) 1448
• Obs 116 (1996) 121 comment
• PASP 109 (1997) 73
• QJRAS 37 (1996) 261