Tuesday, May 17, 2011

Biography of Subrahmanyan Chandrasekhar

Biography of Subrahmanyan Chandrasekhar

    Subrahmanyan Chandrasekhar was an Indian-born American astronomer of the 20th century. The majority of his work focused on the structures and life cycles of stars. His most prominent studies were conducted on the subject of radiation emitted from stars, particularly white dwarf stars. He was the first to discover that higher mass white dwarfs have smaller radii, and made many contributions to astrophysics regarding stars, including the establishment of the Chandrasekhar limit.
    Chandrasekhar was born on October 19, 1910, in Lahore, India (which today is part of Pakistan) as the first son of what would eventually be a family of 12. Chandra received his first education from his parents starting at age 5. His mother taught him Tamil and his father taught him English and arithmetic. Quite early on, Chandra already had his sights set on being a scientist of some description, and to that end he began to study physics and calculus on his own. By 1918, the family had moved south to Madras where he was taught by tutors until 1921, when he enrolled in Hindu High School in Triplicane. Quickly becoming the head of the class, Chandra finished high school by age 15, at which time he began attending in Presidency College in Madras. Despite his father’s wishes that he pursue physics, Chandra’s studies were mainly focused on mathematics.
    After Chandra graduated with an M.A. in 1930, he set off for Trinity College, Cambridge, courtesy of a special government scholarship. During the long journey from India to Cambridge, Chandra began working out his own theory on stellar evolution. Inspired by his idea, Chandra turned to astrophysics studies once he arrived at Cambridge. In 1932, he was inducted into the Royal Astronomical Society. It was at one of the meetings of the RAS that Chandra stated his ideas about the stellar life cycle, specifically that not all stars that deplete their hydrogen reserves can end their lives as stable white dwarfs. If the mass of an evolving star exceeds a certain limit, he proposed, the star may instead go supernova, and become an even denser neutron star. This mass limit, which was eventually calculated to be 1.4 solar masses, would be known as the Chandrasekhar limit, and would become the discovery that made Chandra a name for himself. Unfortunately, the theory wouldn’t actually be widely accepted for another 20 years.
    Chandra then spent time at Harvard University from 1935-1936, was offered a research position at the Yerkes Observatory in Williams Bay, Wisconsin, and would eventually move to the United States as a permanent resident. During World War II, he was employed at Aberdeen Proving Ground in Maryland doing research in ballistics and shock waves. In 1942, he was promoted to associate professor of astrophysics at the University of Chicago, and around 1944, shifted his research from stellar dynamics to radiative transfer. Chandra became an official U.S. citizen in 1953, and despite receiving numerous offers from all over the world, he never left the University of Chicago until 1980, when he voluntarily retired. Throughout his career, he received numerous awards and accolades, including the National Medal of Science of the United States, the Lincoln Academy Award of Illinois, and the Nobel Prize in Physics. Chandrasekhar died on August 21, 1995, at the age of 84.

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