Meghnad Saha

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Meghnad Saha
Born(1893-10-06)6 October 1893
Shaoratoli, Dhaka District, Bengal Presidency, India (modern-day Kaliakair Upazila, Gazipur District, Bangladesh)
Died16 February 1956(1956-02-16) (aged 62)
New Delhi, India
Alma mater
Known for
SpouseRadha Rani Saha
Scientific career
FieldsPhysics, astrophysics
Academic advisors
Doctoral students
Member of Parliament, Lok Sabha
In office
3 April 1952 – 16 February 1956
Preceded byFormed
Succeeded byAshoke Kumar Sen
ConstituencyCalcutta North West
Personal details
Political partyIndependent politician

Meghnad Saha FRS[1] (6 October 1893 – 16 February 1956) was an Indian astrophysicist who helped devise the theory of thermal ionisation. His Saha ionisation equation allowed astronomers to accurately relate the spectral classes of stars to their actual temperatures. Saha's equation is considered one of the ten most outstanding discoveries in astronomy and astrophysics since Galileo's invention of the telescope in 1608. [2][3][4] He was elected as an independent member to the Parliament of India in 1952.[4][5]


c. 1934

Meghnad Saha was born in 1893 into a poor Bengali Hindu Teli family in Shaoratoli village, Dhaka district, Bengal Presidency of British India (present-day Gazipur District, Bangladesh). He was the son of grocer Jagannath Saha and Smt. Bhubaneshwari Devi.

During his youth, he was forced to leave Dhaka Collegiate School because he participated in the Swadeshi movement.[6] After that he joined K. L. Jubilee High School & College. He earned his Indian School Certificate from Dhaka College.[6] He was also a student at the Presidency College, Kolkata and Rajabazar Science College CU. Saha faced discrimination from other students due to his caste; when he was at the Eden Hindu Hostel, upper-caste students objected to him eating in the same dining hall as them.[2][7]

He was a professor at Allahabad University from 1923 to 1938, and thereafter a professor and Dean of the Faculty of Science at the University of Calcutta until his death in 1956. He became a Fellow of the Royal Society in 1927. He was president of the 21st session of the Indian Science Congress in 1934.[8]

Amongst Saha's classmates were Satyendra Nath Bose, Jnan Ghosh and Jnanendra Nath Mukherjee. In his later life, he was close to Amiya Charan Banerjee.[9][10] Saha was an atheist.[11][12]


Saha's study of the thermal ionisation of elements led him to formulate what is known as the Saha ionisation equation. This equation is one of the basic tools for interpreting the spectra of stars. By studying the spectra of stars, one can find their temperature and using Saha's equation determine the ionisation state of the elements making up the star. This was extended by Ralph H. Fowler and Edward Arthur Milne. Saha had previously reached the following conclusion on the subject:

It will be admitted from what has gone before that the temperature plays the leading role in determining the nature of the stellar spectrum. Too much importance must not be attached to the figures given, for the theory is only a first attempt for quantitatively estimating the physical processes taking place at high temperature. We have practically no laboratory data to guide us, but the stellar spectra may be regarded as unfolding to us, in an unbroken sequence, the physical processes succeeding each other as the temperature is continually varied from 3000 K to 40,000 K.[13]

Saha also invented an instrument to measure the weight and pressure of solar rays.

Meghnad Saha helped to establish several scientific institutions, including the Physics Department at Allahabad University in United Provinces (now Uttar Pradesh) and the Institute of Nuclear Physics (now Saha Institute of Nuclear Physics) in Kolkata. He founded the journal Science and Culture and was the editor until his death.[14] He was the leading figure in organising several scientific societies, such as the National Academy of Science (1930), the Indian Physical Society (1934), and the Indian Institute of Science (1935). He was the director at Indian Association for the Cultivation of Science from 1953 to 1956. The Saha Institute of Nuclear Physics, founded in 1943 in Kolkata, is named after him.[15]

Saha stood as a candidate for North-West Calcutta in the 1951 Lok Sabha election. He ran as a member of the Union of Socialists and Progressives,[16][17][18] but maintained his independence from the party. His goal was to improve the planning of education, industrialisation, healthcare, and river valley development. He was up against Prabhu Dayal Himatsingka. Due to low funding for his campaign, Saha wrote to the publisher of his textbook Treatise on Heat to ask for an advance of ₹5000. He was elected by a margin of 16%.[19]

Saha participated in the areas of education, refugees, rehabilitation, atomic energy, multipurpose river projects, flood control, and long term planning. In the book Meghnad Saha in Parliament, Saha is described as:

"Never unduly critical... forthright, so incisive, so thorough in pointing out lapses that the treasury bench was constantly on the defensive. This is brought out by the way he was accused of leaving his laboratory and straying into a territory not his own. But the reason why he was slowly drifting towards this public role (he was never a politician in the correct sense of the term) was the gradually widening gulf between his dream and the reality—between his vision of an industrialised India and the Government implementation of the plan."[20]

Saha was the chief architect of river planning in India and prepared the original plan for the Damodar Valley Project. His own observation with respect to his transition into government projects and political affairs was:

Scientists are often accused of living in the "Ivory Tower" and not troubling their mind with realities and apart from my association with political movements in my juvenile years, I had lived in ivory tower up to 1930. But science and technology are as important for administration now-a-days as law and order. I have gradually glided into politics because I wanted to be of some use to the country in my own humble way.[21]

Meghnad Saha


Saha died on the way to the hospital on 16 February 1956 after getting cardiac arrest. He was going to the office of the Planning Commission in the Rashtrapati Bhavan. It was reported he had been dealing with hypertension for ten months prior to his death.[22] His remains were cremated at the Keoratola crematorium, Kolkata the following day.[23]

Saha with other scientists at Calcutta University


Bust of Saha at Indian Association for the Cultivation of Science.
Statue of Saha, University College of Science, Technology & Agriculture.
Bust of Saha in Birla Industrial & Technological Museum.
  • "Meghnad Saha's ionization equation (c. 1920), which opened the door to stellar astrophysics was one of the top ten achievements of 20th century Indian science [and] could be considered in the Nobel Prize class." — Jayant Narlikar[24]
  • "The impetus given to astrophysics by Saha's work can scarcely be overestimated, as nearly all later progress in this field has been influenced by it and much of the subsequent work has the character of refinements of Saha's ideas." — Svein Rosseland[25]
  • "He (Saha) was extremely simple, almost austere, in his habits and personal needs. Outwardly, he sometimes gave an impression of being remote, matter of fact, and even harsh, but once the outer shell was broken, one invariably found in him a person of extreme warmth, deep humanity, sympathy and understanding; and though almost altogether unmindful of his own personal comforts, he was extremely solicitous in the case of others. It was not in his nature to placate others. He was a man of undaunted spirit, resolute determination, untiring energy and dedication." — Daulat Singh Kothari[26]


  1. ^ Kothari, D. S. (1 February 1960). "Meghnad Saha, 1893–1956". Biographical Memoirs of Fellows of the Royal Society. 5: 216–236. doi:10.1098/rsbm.1960.0017. S2CID 121719435.
  2. ^ a b Banerjee, Somaditya (1 August 2016). "Meghnad Saha: Physicist and nationalist". Physics Today. 69 (8): 38–44. Bibcode:2016PhT....69h..38B. doi:10.1063/PT.3.3267. ISSN 0031-9228.
  3. ^ "Meghnad N. Saha | Indian astrophysicist". Encyclopædia Britannica. Archived from the original on 26 December 2018. Retrieved 23 November 2016.
  4. ^ a b Kean, Sam (2017). "A forgotten star". Distillations. 3 (1): 4–5. Archived from the original on 23 March 2018. Retrieved 22 March 2018.
  5. ^ "Meghnad N. Saha | Indian physicist, scientist | Britannica". 5 April 2024. Retrieved 12 April 2024.
  6. ^ a b Madhumita Mazumdar and Masud Hasan Chowdhury (2012), "Saha, Meghnad", in Sirajul Islam and Ahmed A. Jamal (ed.), Banglapedia: National Encyclopedia of Bangladesh (Second ed.), Asiatic Society of Bangladesh, archived from the original on 10 January 2017, retrieved 6 February 2016
  7. ^ "Even a scientist wasn't spared caste discrimination". Newslaundry. 27 October 2017.
  8. ^ Murty, K. Krishna (2008). 50 timeless scientists. Delhi: Pustak Mahal. pp. 97–100. ISBN 9788122310306. Archived from the original on 26 December 2018. Retrieved 28 July 2017.
  9. ^ Bose, D.M. (1967). "Meghnad Saha Memorial Lecture, 1965" (PDF). Proceedings of the Indian National Science Academy. 33A: 111–132. Archived (PDF) from the original on 28 July 2017. Retrieved 28 July 2017.
  10. ^ Wali, Kameshar C. (2009). Satyendra Nath Bose : his life and times. Singapore: World Scientific. p. 462. ISBN 978-9812790712. Archived from the original on 26 December 2018. Retrieved 28 July 2017.
  11. ^ Chatterjee, Santimay; Chatterjee, Enakshi (1984). Meghnad Saha, scientist with a vision. National Book Trust, India. p. 5. Even though he later came to be known as an atheist, Saha was well-versed in all religious texts— though his interest in them was purely academic.
  12. ^ Robert S. Anderson (2010). Nucleus and Nation: Scientists, International Networks, and Power in India. University of Chicago Press. p. 602. ISBN 9780226019758. a self-described atheist, saha loved swimming in the river and his devout wife loved the sanctity of the spot. swimming and walking were among the few things they could do together.
  13. ^ Hearnshaw, John B. (2014). The Analysis of Starlight: Two Centuries of Astronomical Spectroscopy (2nd ed.). Cambridge University Press. p. 136. ISBN 978-1-107-03174-6.
  14. ^ Eminent scientists published by Scholastic India pvt. Ltd.
  15. ^ Anderson, Robert S. (2010). Nucleus and Nation Scientists, International Networks, and Power in India. Chicago: University of Chicago Press. ISBN 9780226019772.
  16. ^ "Members Bioprofile". Archived from the original on 6 March 2018. Retrieved 5 March 2018.
  17. ^ "Biographical Sketch of First Lok Sabha (State wise)". Archived from the original on 6 March 2018. Retrieved 5 March 2018.
  18. ^ "Members : Lok Sabha". Archived from the original on 6 March 2018. Retrieved 5 March 2018.
  19. ^ "Statistical Report on General Elections, 1951 to the First Lok Sabha" (PDF). Archived (PDF) from the original on 4 March 2016. Retrieved 5 March 2018.
  20. ^ Gupta, Jyotirmoy (1993). Meghnad Saha In Parliament.
  21. ^ "Meghnad Saha". Archived from the original on 23 February 2015. Retrieved 31 May 2008.
  22. ^ "Nation Mourns Meghnad Saha". The Indian Express. 17 February 1956. pp. 1, 7.
  23. ^ "Saha's Remains Cremated". The Indian Express. 18 February 1956.
  24. ^ Narlikar, Jayant (2003). The Scientific Edge. Penguin Books. p. 127.
  25. ^ Rosseland, S. (1939). Theoretical Astrophysics. Oxford: Oxford University Press. Archived from the original on 23 February 2015.
  26. ^ Kothari, D. S. (1970). Biographical Memoirs of Fellows of the National Institute of Sciences of India. Vol. 2. New Delhi. Archived from the original on 23 February 2015.{{cite book}}: CS1 maint: location missing publisher (link)

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