It is 1983 and the most prestigious award in Physics, the Nobel Prize, is being granted in two physicists, one of them being Subrahmanyan Chandrasekhar. His colleagues, his friends, his family and his students are not surprised. They believe, this scientific recognition that comes along with the highest honor, should have been made about 50 years ago. Chandrasekhar himself, has mixed feelings: happiness, since his work is being recognized at last, but also disappointment, because the award is referred to some of his first findings, meaning a lot of his later hard work is remaining unnoticed.
His whole life as well as his work, could be perfectly described by Shakespeare’s lyrics in A Midsummer’s Night Dream. Recognized or not, his work was so remarkable that changed the field of physics forever and for this, we decided to get to know this great scientist, who shed light on the life of the stars, with his bright mind.
Chandrasekhar was born on 19 October 1910 in Lahore, Pakistan, which back then was ruled by the British. He grew up in an open-minded environment which promoted education and supported his scientific pursuit. He was home-schooled until the age of twelve by his parents and graduated from high school at the age of fifteen, when he began studying at the University of Madras and got his bachelor’s degree in Physics, four years later. He was still an undergraduate student when he made his first scientific publication. For this publication, he asked Ralph Fowler for advice, with whom he was going to share the Nobel Prize some decades later.
In 1930, he managed to claim a scholarship to pursue a master’s degree in the University of Cambridge. During his trip towards Europe, an excellent idea is born in the brilliant mind of the young student. “What if we apply the Special Relativity Theory in dying stars?”, he wondered. Einstein’s theory of special relativity was already known since 1905, but beside the recognition, the theory was not fully tested. Until then, the scientific community knew that dying stars, meaning stars that have converted all their hydrogen into helium, don’t have any more energy and cannot emit radiation, resulting in collapsing towards their center, due to gravity. This stellar corpse that we end up with, is roughly the same size as Earth, but with great density and is consisted of a “soup” of electrons and atomic nucleus. What Chandrasekhar was thinking, was: “what would happen if these electrons in the interior of the star were moving with high velocities close to the speed of light?”. A few nautical miles later, his creative thinking was completed. His mathematical reasoning led him to the unusual conclusion that all stars cannot have the same fate. Those with smaller mass, should indeed, follow the path we just described, but those with bigger mass, should continue collapsing while explode their external layers in an impressive burst.
Artistic representation of a neutron star(source: www.sciencenews.org)
Chandrasekhar himself, didn’t realize the importance of his discovery and its meaning for future physicists. Objects that were later discovered, like neutron stars and black holes, that were much denser than white dwarfs, couldn’t be explained with the existing theories at that time. They were objects that exceeded the upper limit Chandrasekhar proposed for the initial stellar mass, up to which all the stars were going to end up as white dwarfs. These bigger objects that part with their external layers, have a major contribution to the diffusion of different chemical elements even in the most isolated corners of our Universe. Humans are also made of these elements. The mystery of our existence could have been kept a secret for longer if this bright mind didn’t figure out our stellar origin.
Even though Chandrasekhar’s theory became the base of modern astrophysics, at that time, it had to deal with a lot of critique and even rejection by the conservative scientific community of Great Britain. The main rival for the recognition of his theory, was Arthur Eddington, who was probably the most prominent astrophysicist of his time. A few years ago, he had completed one of his most important projects, which was about the internal stellar structure and eventually their destiny. As a result, the proposition of this young Indian student didn’t just seem obscure to Eddington, but it was also completely opposite to his own, internationally known work. He even got to the point where during the conference of the Royal Astronomical Society, in 1935, he humiliated Chandrasekhar by calling his idea a “stellar absurdity”, full of cruelty and cynicism. Even though, some members of the scientific community didn’t agree with him, nobody dare to doubt what Eddington said. As for the reason, it is obvious. How could an unknown Indian immigrant ever disprove a well-known British astrophysicist?
That could never happen as the history proved. This immigrant though, was already a PhD holder, since 1933 and was working as a researcher in Cambridge. He was, only the second Indian man to achieve this. After all this, his confidence was ruined, but he never gave up. At the same time, he came across and collaborated with a lot of scientists from all over the world, some of them being prominent and well-known scientists, like Niels Bohr and Paul Dirac.
These acquaintances helped him get away from English conservatism and develop professionally. As a result, he earned the title of a professor in the University of Chicago, where he remained until the end of his career. Within only 4 years, he obtained a permanent position, at the age of 33. Wanting to deviate a bit from his original research field, he turned his interest towards different subjects, such as stellar dynamics, mechanisms of radiative diffusion in stellar atmospheres and black holes. He tried to choose each new subject according to his interests and abilities and after conducting research on it. He dealt with every topic in a methodical and dedicated manner, studying it thoroughly and he proceeded to publications only after he had a global view and felt comfortable with it. He even wrote down all the existing information about a topic in books that stood out for their good structure and use of mathematics.
His recognition, came at last, gradually and sparingly. His respected figure led Robert Oppenheimer to offer Chandrasekhar collaboration in the Manhattan Project, for producing nuclear weapons during World War II. Unfortunately, this collaboration didn’t flourish due to bureaucratic reasons. He was awarded a few times, with the most important award being the metal of Royal Astronomical Society in 1953 (ironically, the metal came from the same Society that alienated him from its circles).
In 1983, the delayed Nobel Prize came to honor his theoretical contribution to stellar structure and evolution. Why then? Because there was undeniable proof to support his proposition. Even though, racism and dogmatism, didn’t remove him from the astrophysical scene, they put astrophysical evolution on ice for about 30 years. However, during the Cold War and the first attempts for constructing hydrogen bombs, it became clear that this kind of bombs behave like a stellar explosion and so his theory that was rejected in 1935, was then investigated further. Furthermore, in 1971 the first black hole was found. All this led to one of the most important discoveries of the 20th century.
The mass limit, above which stars don’t end up as white dwarfs, was named after him, Chandrasekhar limit. Moreover, the 1958 Chandra asteroid, the Chandra X-ray observatory that is still scanning the sky outside our atmosphere and the Himalayan Chandra Telescope, were all named after the same person.
This man won after all because he had faith in himself and because of his persistence. A great assistant, during his lifetime, was his beloved wife, Lalitha Doraiswamy. He died on 21 August 1995, leaving as a heritage, his scientific method and work. Now, one century after he was born and that his story is being rediscovered, we owe to remember the name of the man who stood up to prejudices and strongly supported our stellar origin. Subrahmanyan Chandrasekhar.
Translation: Zoi Filiou
Proof-reading: Giorgos Alexandris
