Prof. Subrahmanyan Chandrasekhar FRS – Astrophysicist

Subrahmanyan Chandrasekhar FRS- Astrophysicist

“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.” 
― Subrahmanyan Chandrasekhar talking about the nature of scientific research

Profile:

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Image of a young Prof. Chandrasekhar. Source: http://chandra.harvard.edu/resources/illustrations/chandraPortraits.html

Name: Professor Subrahmanyan Chandrasekhar

Life: 19 October 1910 – 21 August 1995 (died aged 84).

Degrees: B.Sc: Presidency College (Madras, India).

                  Ph.D: Trinity College, Cambridge

Occupation:  Astrophysicist and research professor

[1][2]

Who was Prof. Subrahmanyan Chandrasekhar?

Prof. Subrahmanyan Chandrasekhar was born in Lahore, Punjab (now Pakistan) during the time of the British occupation of India. He was born into a large Tamil family, with his paternal uncle being Sir Chandrasekhara Venkata Raman, a famous Indian physicist who won the 1930 Nobel Prize for his ground-breaking work in the field of light scattering, most notably his discovery of how light changes wavelength when it traverses a transparent material, which was named Raman scattering after him. [1][9]

Chandrasekhar’s mother and father were also key in encouraging him and aiding his academic abilities, as Chandrasekhar was home-schooled until the age of 12, with his father tutoring him in maths and physics, and his mother teaching him Tamil. Chandrasekhar’s mother, Sitalakshmi Balakrishnan, is credited as being key in rousing his intellectual curiosity and herself was dedicated to intellectual pursuits; she was responsible for translating Henrik Isben’s famous play “Doll House” into Tamil.[1][3]

After the age of 12, he attended the Hindu High School in Madras, a school set up at a time where many Indian parents were incredibly reluctant to send their children to the school as they were run by the British, (such as those run by the British East India Company).[1]

From 1925 (at the age of just 15!) he studied at Presidency College, Madras, where he wrote his first paper “The Compton Scattering and the New Statistics“, and graduated with his bachelor’s degree in physics in June 1930.

One month later, the government of India awarded Chandrasekhar with a scholarship so he could continue his studies at Trinity College, Cambridge, and here he started his graduate studies at the tender age of 19. [2]

What did Chandrasekhar’s work focus on?

On his voyage to England in 1930, Chandrasekhar worked out that there was a maximum mass for a stable white dwarf star. [2]  A white dwarf star is what Sun-like stars turn into once all of their nuclear fuel has been exhausted. Because the white dwarf can’t release energy from fusion (as all the fuel has gone), the electrons in the white dwarf are squashed together via the force of gravity, causing all the energy levels inside the atoms to fill up completely. In order to not violate the Pauli Exclusion Principle (which states that no two electrons can occupy the same quantum state), electron “degeneracy pressure” prevents the white dwarf from undergoing gravitational collapse. Chandrasekhar worked out is that this is only possible when the mass of the white dwarf is less than or equal to 1.44 Solar Masses. This was then named the Chandrasekhar limit; beyond this mass limit the white dwarf undergoes further gravitational collapse becoming either a neutron star or black hole. [4]

Chandrasekhar’s graduate research involved calculating opacities and applying these results to an improved model for the mass limit of a degenerate star, and later on in his second year, he moved on to looking at atomic absorption coefficients and modelling stellar protospheres (solar/stellar surface layers which visible radiation escapes from).  In 1933, Chandrasekhar was awarded a bronze medal for his work on degenerate stars and in the summer of 1933, received his Ph.D, which was awarded for his thesis on rotating self-gravitating polytropes and he was elected to receive a Prize Fellowship at Trinity College.[1][10]

In 1937, Chandrasekhar was made an assistant professor at the University of Chicago, and would remain at this institution for his entire career, becoming a Morton D.Hull Distinguished Service Professor of Theoretical Astrophysics in 1962. He also worked at the Yerkes Observatory in Williams Bay, Wisconsin and during WWII he worked at the Ballistic Research Laboratory in Maryland, becoming an expert in hydrodynamics. While working at Yerkes Observatory, Chandrasekhar would drive 150 miles to and fro each weekend to teach a course at the University of Chicago, showing his dedication towards helping his students with their research and studies.[1][2]

From 1952 to 1957 Chandrasekhar was editor of The Astrophysical Journal, and in 1983 was awarded a Nobel Prize for Physics along with William A. Fowler for “theoretical studies of the physical processes of importance to the structure and evolution of the stars.” Between 1990 and 1995, Chandrasekhar worked on explaining Newton’s “Principia Mathematica” using simple calculus, showing a genuine desire to make complicated physics principles understandable to the masses, and in 1995, “Newton’s Principia for the Common Reader” was published.[1][2][9]

What racism and hardships did Chandrasekhar face?

After his work calculating the Chandrasekhar limit, Chandrasekhar arrived in Cambridge full of hopes and dreams and excitement about his academic future, however many scientists he met ridiculed the concept of there existing such a mass limit for white dwarfs. Due to this hostile attitude and feeling utterly alone, his mental health declined. As science writer Arthur Miller states in [11]:

“He had grown up in a free-thinking Brahmin household in Madras and had been recognised as a prodigy from an early age. He had already completed his undergraduate degree and had published several scientific papers. The daily reminders that India was under the yoke of the British Empire rankled him and science seemed a way to show that he was at least equal to the colonial masters… At Cambridge his hopes were dashed. Scientists there ignored his discovery. Cast down by the dank fens and dreary weather, utterly unlike the welcoming warmth of south India, he gave way to depression.”

In spite of his depression, Chandrasekhar pushed through to complete his Ph.D and it was around this time he made acquaintance with Sir Arthur Stanley Eddington, a scientist who was very famous for his work concerning the theory of relativity. Eddington suggested that Chandrasekhar should announce his conclusion about the stable white dwarf mass limit at a meeting of the Royal Astronomical Society, and Chandrasekhar was elated.[1][2][3]

On the 11th of January 1935, Chandrasekhar delivered a presentation of his results to RAS, however, to his horror, Eddington stood up and instead of stating his approval of Chandrasekhar’s work, he unleashed a vicious verbal attack on the young man’s discovery, ridiculing it in front of the renowned astrophysicists present. Chandrasekhar was upset and heartbroken that a mentor he trusted would betray him in such a cruel, vile way. [2]

At the end of the meeting, Eddington and Chandra had a brief moment alone. “I am sorry if I hurt you,” Eddington said to Chandra. Chandra asked whether he had changed his mind. “No,” Eddington retorted. “What are you sorry about then?” Chandra replied and brusquely walked away.  This showed that even at the young age of 25, Chandrasekhar knew his intellectual worth and was not prepared to let Eddington get away with such rudeness, and when in his later years Chandrasekhar was asked about why Eddington had acted in such a manner, he replied that Eddington’s behaviour was racially motivated. (This turned out to be true considering the work Chandrasekhar presented was literally correct and is now commonly taught in the physics curriculum). [1][2]

The reason Chandrasekhar left Cambridge for the University of Chicago was because he felt that his life and career had been blighted by racism, and the emotional toll that it had taken on him proved too great for him to continue working there.  40 years after his initial discovery of the Chandrasekhar limit (as a mere 19 year old on a ship to England), he was proven correct through the first identification of a black hole (the result of an unstable white dwarf) Cygnus X-1 in 1972. [2][3]

Chandrasekhar’s genius cannot be overstated; not only was he a pioneer in astrophysics, he mastered several different other fields of physics, and published books and papers on Brownian motion, radiative transfer and fluid dynamics. He guided 45 students to obtaining PhD’s, and his legacy reflects how much he cared for his students. After his death, his widow, Lalitha Chandrasekhar gifted his Nobel Prize money to the University of Chicago in order to set up the Subrahmanyan Chandrasekhar Memorial Fellowship. [5]The Chandra Astrophysics Institute (CAI) is a program offered for high school students who are interested in astrophysics, which is mentored by MIT scientists and sponsored by the Chandra X-ray Observatory. [6]

A list of honours bestowed on Subrahmanyan Chandrasekhar can be found below:

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.“[12]

References:

References are categorised by the following types:

🗒️ = Written 

🎧 = Audio

💻 = Video

[1]🗒️ – Wikipedia – https://en.wikipedia.org/wiki/Subrahmanyan_Chandrasekhar#cite_note-12

[2]🗒️ – The Guardian article: “S Chandrasekhar: the student who took on the world’s top astrophysicist” – https://www.theguardian.com/education/2005/mar/31/research.highereducation

[3]🗒️ – Al Jazeera article: “S Chandrasekhar: Why Google honours him today” – https://www.aljazeera.com/news/2017/10/chandrasekhar-google-honours-171018135910958.html

[4]🗒️ – NASA website (Goddard Space Flight Centre) – https://imagine.gsfc.nasa.gov/science/objects/dwarfs2.html

[5]🗒️ – University of Chicago – Astronomy and Astrophysics department website – https://astro.uchicago.edu/academics/chandrasekhar-fellowship.php

[6]🗒️ – Massachusetts Institute of Technology website: – https://ocw.mit.edu/high-school/physics/chandra-astrophysics-institute/

[7]🗒️ – University of Chicago library website – https://www.lib.uchicago.edu/e/scrc/findingaids/view.php?eadid=ICU.SPCL.CHANDRASEKHAR

[8]🗒️ – K.C. Wali, “Chandrasekhar vs. Eddington: An Unanticipated Confrontation”, Physics Today, vol. 35, no. 10, pp. 33–40 (October, 1982)

[9]🗒️ – Wikipedia – https://en.wikipedia.org/wiki/C._V._Raman

[10]🗒️ – Nobel Prize website – https://www.nobelprize.org/prizes/physics/1983/chandrasekhar/auto-biography/

[11]🗒️ – Miller, Arthur I. (2005). Empire of the Stars: Friendship, Obsession, and Betrayal in the Quest for Black Holes. Boston: Houghton Mifflin. ISBN 978-0-618-34151-1.

[12]🗒️ – Tayler, R. J. (1996). “Subrahmanyan Chandrasekhar. 19 October 1910 – 21 August 1995”. Biographical memoirs of Fellows of the Royal Society 42: 80 94. doi:10.1098/rsbm.1996.0006.

Authors Note: Although after his dispute with Eddington, Chandrasekhar clearly went on to achieve outstanding greatness in the field of physics, it hurts to know that at such a young age he had to face so much hardship due to a racist mentor (Eddington); someone he should have been able to trust to guide him. It is important therefore that a critical eye be taken to so-called “scientific greats” such as Eddington, and to make sure they are not deified: and as can be seen with how he reacted to Chandrasekhar, they can be bigoted, racist and terrible people, regardless of their intellectual prowess.

For more information on POC scientists please visit our resources page or read through the rest of our blog. We are constantly updating both.

Written by Pruthvi Mehta. For more information see the about page or follow her on Twitter @q_the_ordinary.

 

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