Chandrasekhar (Chandrasekhar), Subrahmanyan( Indian-American astrophysicist Nobel Prize in Physics, 1983)
Comments for Chandrasekhar (Chandrasekhar), Subrahmanyan
Biography Chandrasekhar (Chandrasekhar), Subrahmanyan
born October 19, 1910
Indian-American astrophysicist Subrahmanyan Chandrasekhar was born in Lahore, India (now Pakistan). He was the first son and the third of ten children Chandrasekhar Subrahmani Aiyar, Indian government officials and musicologist, and his wife Sita (before marriage Balakrishnan), a teacher of literature and linguistics. Inspired by the example of his uncle, the physicist Venkata Ramana, the boy decided to become a scientist. Chandra (as he always called), he studied at home under the guidance of parents and visiting teachers, and in 1922. enrolled in school in Madras, where the family moved in 1918. Leaving school in 1925, he entered the Presidential College, University of Madras, where the chosen main subject of physics, is particularly interested in the latest discoveries in astrophysics. He received a bachelor's degree with honors in 1930. Even as a undergraduate, he was in 1928. published article, which analyzed the thermodynamics of the Compton effect (on behalf of Arthur X. Compton) in connection with the processes inside stars.
Received the Indian government scholarship to study in graduate school at Cambridge University, Ch. in 1930. went by sea to the shores of England. During the long journey, he read the book Arthur Eddington 'internal structure of stars', which received as a reward for the physical contest. In this book, an eminent British astronomer claimed that all the stars, when the fuel is exhausted, who supported a nuclear reaction, are compressed under its own weight, highlighting the excess energy in the space. Such a star like the Sun shrinks to a white hot ball of the size of Earth, called a white dwarf, with a density of 10 tons per cubic centimeter, then it will simply cool down, the rest remain forever unchanged. At Trinity College in Cambridge B. studied the behavior of dying stars led by physicist Ralph Howard Fowler, . and at the age of twenty-one years he published three works 'configurations of stellar mass at high compression' ( "The Highly Collapsed Configurations of a Stellar Mass"), . 'The maximum mass of ideal white dwarfs' ( "The Maximum Mass of Ideal White Dwarfs") and 'density of white dwarfs' ( "The Density of White Dwarf Stars"),
. In these studies H. argues with Eddington. Eddington's views largely shared by Fowler, . pointing, . that stars form when compressing the size of planetary objects, . who are either white dwarfs, . red-hot and bright, respectively, . or brown dwarfs, . cold and rather dull.,
. On the advice of P.A.M
. Dirac h. Last year, his doctoral research conducted at the Niels Bohr Institute for Theoretical Physics in Copenhagen. After receiving his doctorate in 1933, he was 4 years was a member of the Academic Council of Trinity College. All the while he continued to study the stars.
In his early works H. showed that large and small stars behave differently after the fire will go out of their nuclear. With the help of quantum mechanics and relativity theory, he analyzed the behavior of stellar material in the process of compression, with particular attention to electronic. If a star's mass is sufficiently small, the gravitational pressure, causing compression gradually balanced by internal pressure, and the star reaches equilibrium with the size of the white dwarf. This conclusion remains true regardless of whether, . whether we calculate the internal pressure with the help of classical physics, . where it is primarily a source of thermal energy of electrons, . or in the framework of quantum mechanics, . when you have to take into account the value, . called the Fermi energy (on behalf of Enrico Fermi), . which depends on the density of electrons,
. However, if a star's mass exceeds a certain amount, then the electrons will gradually shrink to such an extent that their speed would be close to the speed of light, a condition called relativistic degeneracy. As a result of gravitational contraction surpass opposing forces and the star will continue to shrink to an incredibly small size and great density of the critical mass of the star, . below which the star can become a white dwarf, . now known as the Chandrasekhar limit of,
. It is 1,4 times the mass of the Sun.
From the general theory of relativity Albert Einstein was known that the massive stars, whose dimensions are compressed less than a certain radius, will not let them get away with the surface of any emissions. They become invisible. Calculations V. predicted what is now known as 'black holes'.
By 1934, Mr.. These calculations resulted in H. to the prediction of yet another stellar event compressing a dead star with a mass in 2 or 3 times the mass of the Sun, will provide a tremendous amount of energy that turned into a supernova explodes. Its outer shell is ejected into space, and the balance shrinks to a stable neutron star, does not contain electrically charged electrons and protons. Its density should be about 100 million. tons per cubic centimeter.
In January next year, at age 24, W. was invited to a meeting of the Royal Astronomical Society in London, where he was asked about his calculations. Only the day before he, to his horror, found out that Eddington also make a presentation at this meeting. He and Eddington, with whom they became friends for months discussing the idea of Charles, but Eddington has never hinted that he is working in the same direction, and show no desire to publicly challenge the views V. After H. finished his report, Eddington, 52-year-old world-famous astronomer, made a deeply offensive ironic refutation 'There is no relativistic degeneracy, he said, rejecting the idea of' black hole 'as absurd. I think that there should be a law of nature, not allowing the star to behave so ridiculous'.
Although Eddington not confirmed its denial of something significant, H. was in terrible condition. No one spoke publicly in his defense, but such eminent physicists as Niels Bohr and Wolfgang Pauli, a privately reassured him. He quit his job and even remained on friendly terms with the Eddington. After his ideas were ridiculed Eddington, prospects take a strong position in the scientific community in Britain have become very shaky, and in 1937. He moved to the United States, occupying the post of Research Fellow at the University of Chicago. In 1938. CH. became an associate professor in 1944. full professor and in 1947. honorary professor of astrophysics.
After studies on the structure of stars H. investigated the stellar dynamics, especially the dynamic friction, slowing the movement of any star in the galaxy because of the gravity surrounding stars. Between 1943 and 1950. He developed the theory of radiative transfer, is important for understanding the stellar atmosphere, the stellar brightness and education of the spectral lines, as well as for the atmosphere of planets and the polarization of the light falling from the sky on a sunny day. During the Second World War, he served as a consultant to the War Department at Aberdeen Proving Ground (Maryland). University of Chicago participated in the Manhattan Project to build the atom bomb and H. also contributed, working with Fermi, James Franck and others.
. In addition, he studied the hydrodynamics and hydrodynamic resistance (1952 1961), equilibrium and stability of ellipsoidal figures of revolution (1961 1968), as well as the general theory of relativity and relativistic astrophysics (1962 1971)
. His work on the mathematical theory of 'black holes', held in 1974 ... 1983. Contributed to the confirmation of the very views that challenged the Eddington in 1935. In fact, it was not found a single white dwarf whose mass is greater than would be more than 1.4 times the mass of the sun, and limit Chandrasekhar lay the foundation of modern astrophysics, leading to the recognition of neutron stars and 'black holes'. Perhaps the quasi-stellar object, or quasar, is a 'black hole' in the center of the galaxy. 'Black holes' are determined by the radiation emitted by a substance which is accelerated to very high energy, when it tightens 'black hole'.
W. was awarded in 1983. Nobel Prize in Physics "for his theoretical studies of the physical processes that play an important role in the structure and evolution of stars'. He shared the prize with William Fowler. In his speech, W. quoted a few lines of poetry by Rabindranath Tagore, which referred to the necessity of freedom for creative activity.
Throughout his life, H. was a theorist, and teacher. His doctoral students have been Tszundao Lee and Chen Ning Yang. He was the sole editor of the 'Astrophysical Journal' ( "Astrophysical Journal") from 1951 to 1972. In the rare hours of leisure W. Listening to classical music or reading.
During a visit to India in 1936. CH. married Lalita Doraysvami, college scholarships Presidential. He received U.S. citizenship in 1953
In addition to the Nobel Prize, W. Brusovsky received a gold medal of the Astronomical Society of the Pacific (1952), the gold medal of the Royal Astronomical Society in London (1953), the Rumford Medal of the American Academy of Arts and Sciences (1957). Royal Medal of Royal Society of London (1962), the National Medal 'For his scientific achievements' of the National Science Foundation (1966) and Danny Heineman Prize of the American Physical Society (1974). He is a member of the National Academy of Sciences, the American Academy of Arts and Sciences. American Astronomical Society. The Royal Astronomical Society in London and the Royal Society of London.