Subrahmanyan Chandrasekhar was an Indian-American astrophysicist. His dicroveries led to the currently accepted theory on the later evolutionary stages of massive stars.
Background
Chandrasekhar, better known as Chandra, was born on October 19, 1910, in Lahore, India (now part of Pakistan), the first son of C. Subrahmanyan Ayyar and Sitalakshmi nee (Divan Bahadur) Balakrishnan. Chandra came from a large family: he had two older sisters, four younger sisters, and three younger brothers. As the firstborn son, Chandra inherited his paternal grandfather's name, Chandrasekhar. His uncle was the Nobel Prize-winning Indian physicist, Sir C. V. Raman.
Education
Chandrasekhar was tutored at home initially through middle school and later attended the Hindu High School, Triplicane, Madras.
While studying at Presidency College, Madras, he wrote his first paper, "The Compton Scattering and the New Statistics", in 1929 upon inspiration from a lecture by Arnold Sommerfeld and obtaining his bachelor's degree in physics. 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, secured by Professor R. H. Fowler with whom he communicated his first paper. During his travels to England, Chandrasekhar spent his time working out the statistical mechanics of the degenerate electron gas in white dwarf stars, providing relativistic corrections to Fowler's previous work.
In his first year at Cambridge, as a research student of Fowler, Chandrasekhar spent his time in intensive study, calculating mean opacities and applying his results to the construction of an improved model for the limiting mass of the degenerate star, and was introduced to the monthly meetings of the Royal Astronomical Society, where he met Professor E. A. Milne. At the invitation of Max Born he spent the summer of 1931, his second year of post-graduate studies, at Born’s institute at Göttingen, working on opacities, atomic absorption coefficients, and model stellar photospheres. On the advice of Prof. P. A. M. Dirac, he spent his final year of graduate studies at the Institute for Theoretical Physics in Copenhagen, where he met Prof. Niels Bohr. After receiving a bronze medal for his work on degenerate stars, in the summer of 1933, Chandrasekhar was awarded his PhD degree at Cambridge with a thesis among his four papers on rotating self-gravitating polytropes, and the following October, he was elected to a Prize Fellowship at Trinity College for the period 1933-37.
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. Famously, Chandrasekhar declined many offers from other universities, including one to succeed Henry Norris Russell, the preeminent American astronomer, as director of the Princeton University Observatory.
Chandrasekhar did some work at Yerkes Observatory in Williams Bay, Wisconsin, which was run by the University of Chicago. After the Laboratory for Astrophysics and Space Research (LASR) was built by NASA in 1966 at the University, Chandrasekhar occupied one of the four corner offices on the second floor. Chandrasekhar lived at 4800 Lake Shore Drive, about a mile from the University, after the high-rise apartment complex was built in the late 1960s.
During World War II, Chandrasekhar worked at the Ballistic Research Laboratories at the Aberdeen Proving Ground in Maryland.
Chandra worked closely with his students and expressed pride in the fact that over a 50 year period (from roughly 1930 to 1980), the average age of his co-author collaborators had remained the same, at around 30. He insisted that students address him as "Chandrasekhar" until they received their philosophy's degree, after which time they (as other colleagues) were encouraged to address him as "Chandra".
Truth and Beauty. Aesthetics and Motivations in Science
Newton's Principia for the Common Reader
title
On the decay of plane shock waves
The normal reflection of a blast wave
Views
As a member of the Royal Astronomical Society since 1932, Chandra was entitled to present papers at its twice monthly meetings. It was at one of these that Chandra, in 1935, announced the results of the work that would later make his name. As stars evolve, he told the assembled audience, they emit energy generated by their conversion of hydrogen into helium and even heavier elements. As they reach the end of their life, stars have progressively less hydrogen left to convert and emit less energy in the form of radiation. They eventually reach a stage when they are no longer able to generate the pressure needed to sustain their size against their own gravitational pull and they begin to contract. As their density increases during the contraction process, stars build up sufficient internal energy to collapse their atomic structure into a degenerate state. They begin to collapse into themselves. Their electrons become so tightly packed that their normal activity is suppressed and they become white dwarfs, tiny objects of enormous density. The greater the mass of a white dwarf, the smaller its radius, according to Chandrasekhar. However, not all stars end their lives as stable white dwarfs. If the mass of evolving stars increases beyond a certain limit, eventually named the Chandrasekhar limit and calculated as 1. 4 times the mass of the sun, evolving stars cannot become stable white dwarfs. A star with a mass above the limit has to either lose mass to become a white dwarf or take an alternative evolutionary path and become a supernova, which releases its excess energy in the form of an explosion. What mass remains after this spectacular event may become a white dwarf but more likely will form a neutron star. The neutron star has even greater density than a white dwarf and an average radius of about 15 km. It has since been independently proven that all white dwarf stars fall within Chandrasekhar's predicted limit, which has been revised to equal 1. 2 solar masses.
Quotations:
"The black holes of nature are the most perfect macroscopic objects there are in the universe: the only elements in their construction are our concepts of space and time. "
"Beauty is that to what the human mind responds at its deepest and most profound. "
"Science is a perception of the world around us. Science is a place where what you find in nature pleases you. "
"In some strange way, any new fact or insight that I may have found has not seemed to me as a "discovery" of mine, but rather something that had always been there and that I had chanced to pick up. "
"Indeed, I would feel that an appreciation of the arts in a conscious, disciplined way might help one to do science better. "
"One may ask the question as to the extent to which the quest for beauty is an aim in the pursuit of science. . . . It is, indeed, an incredible fact that what the human mind, at its deepest and most profound, perceives as beautiful finds its realization in external nature. What is intelligible is also beautiful. "
"I am aware of the usefulness of science to society and of the benefits society derives from it. "
"The pursuit of science has often been compared to the scaling of mountains, high and not so high. But who amongst us can hope, even in imagination, to scale the Everest and reach its summit when the sky is blue and the air is still, and in the stillness of the air survey the entire Himalayan range in the dazzling white of the snow stretching to infinity? None of us can hope for a comparable vision of nature and of the universe around us. But there is nothing mean or lowly in standing in the valley below and awaiting the sun to rise over Kinchinjunga. "
"Macroscopic objects, as we see them all around us, are governed by a variety of forces, derived from a variety of approximations to a variety of physical theories. In contrast, the only elements in the construction of black holes are our basic concepts of space and time. They are, thus, almost by definition, the most perfect macroscopic objects there are in the universe. "
Membership
International Academy of Science
1988
Royal Society
,
United Kingdom
1944
Connections
Before taking up the associate position at Yerkes Observatory at Williams Bay, Chandra returned home to India to marry the woman who had waited for him patiently for six years. He had known Lalitha Doraiswamy, daughter of Captain and Mrs. Savitri Doraiswamy, since they had been students together at Madras University. After graduation, she had undertaken a master's degree. At the time of their marriage, she was a headmistress. Although their marriage of love was unusual, as both came from fairly progressive families and were both of the Brahman caste, neither of their families had any real objections. After a whirlwind courtship and wedding, the young bride and groom set out for the United States. They intended to stay no more than a few years, but, as luck would have it, it became their permanent home.
From White Dwarfs to Black Holes: The Legacy of S. Chandrasekhar
From White Dwarfs to Black Holes chronicles the extraordinarily productive scientific career of Subrahmanyan Chandrasekhar, one of the twentieth century's most distinguished astrophysicists. Among Chandrasekhar's many discoveries were the critical mass that makes a star too massive to become a white dwarf and the mathematical theory of black holes. In 1983 he shared the Nobel Prize for Physics for these and other achievements. Over the course of more than six decades of active research Chandrasekhar investigated a dizzying array of subjects. G. Srinivasan notes in the preface to this book that "the range of Chandra's contributions is so vast that no one person in the physics or astronomy community can undertake the task of commenting on his achievements." Thus, in this collection, ten eminent scientists evaluate Chandrasekhar's contributions to their own fields of specialization. Donald E. Osterbrock closes the volume with a historical discussion of Chandrasekhar's interactions with graduate students during his more than quarter century at Yerkes Observatory. Contributors are James Binney, John L. Friedman, Norman R. Lebovitz, Donald E. Osterbrock, E. N. Parker, Roger Penrose, A. R. P. Rau, George B. Rybicki, E. E. Salpeter, Bernard F. Schutz, and G. Srinivasan. From White Dwarfs to Black Holes chronicles the extraordinarily productive scientific career of Subrahmanyan Chandrasekhar, one of the twentieth century's most distinguished astrophysicists. Among Chandrasekhar's many discoveries were the critical mass that makes a star too massive to become a white dwarf and the mathematical theory of black holes. In 1983 he shared the Nobel Prize for Physics for these and other achievements. Over the course of more than six decades of active research Chandrasekhar investigated a dizzying array of subjects. G. Srinivasan notes in the preface to this book that "the range of Chandra's contributions is so vast that no one person in the physics or astronomy community can undertake the task of commenting on his achievements." Thus, in this collection, ten eminent scientists evaluate Chandrasekhar's contributions to their own fields of specialization. Donald E. Osterbrock closes the volume with a historical discussion of Chandrasekhar's interactions with graduate students during his more than quarter century at Yerkes Observatory. Contributors are James Binney, John L. Friedman, Norman R. Lebovitz, Donald E. Osterbrock, E. N. Parker, Roger Penrose, A. R. P. Rau, George B. Rybicki, E. E. Salpeter, Bernard F. Schutz, and G. Srinivasan.
The Theory of Turbulence: Subrahmanyan Chandrasekhar's 1954 Lectures (Lecture Notes in Physics)
In January 1937, Nobel laureate in Physics Subrahmanyan Chandrasekhar was recruited to the University of Chicago. He was to remain there for his entire career, becoming Morton D. Hull Distinguished Service Professor of Theoretical Astrophysics in 1952 and attaining emeritus status in 1985. This is where his then student Ed Spiegel met him during the summer of 1954, attended his lectures on turbulence and jotted down the notes in hand. His lectures had a twofold purpose: they not only provided a very elementary introduction to some aspects of the subject for novices, they also allowed Chandra to organize his thoughts in preparation to formulating his attack on the statistical problem of homogeneous turbulence. After each lecture Ed Spiegel transcribed the notes and filled in the details of the derivations that Chandrasekhar had not included, trying to preserve the spirit of his presentation and even adding some of his side remarks. The lectures were rather impromptu and the notes as presented here are as they were set down originally in 1954. Now they are being made generally available for Chandrasekhar’s centennial.
Chandra: A Biography of S. Chandrasekha
Chandra is an intimate portrait of a highly private and brilliant man, Subrahmanyan Chandrasekhar, a Nobel laureate in physics who has been a major contributor to the theories of white dwarfs and black holes. "Wali has given us a magnificent portrait of Chandra, full of life and color, with a deep understanding of the three cultures—Indian, British, and American—in which Chandra was successively immersed. . . . I wish I had the job of reviewing this book for the New York Times rather than for Physics Today. If the book is only read by physicists, then Wali's devoted labors were in vain."—Freeman Dyson, Physics Today "An enthralling human document."—William McCrea, Times Higher Education Supplement "A dramatic, exuberant biography of one of the century's great scientists."—Publishers Weekly Chandra is an intimate portrait of a highly private and brilliant man, Subrahmanyan Chandrasekhar, a Nobel laureate in physics who has been a major contributor to the theories of white dwarfs and black holes. "Wali has given us a magnificent portrait of Chandra, full of life and color, with a deep understanding of the three cultures—Indian, British, and American—in which Chandra was successively immersed. . . . I wish I had the job of reviewing this book for the New York Times rather than for Physics Today. If the book is only read by physicists, then Wali's devoted labors were in vain."—Freeman Dyson, Physics Today "An enthralling human document."—William McCrea, Times Higher Education Supplement "A dramatic, exuberant biography of one of the century's great scientists."—Publishers Weekly