Megh Nad Saha.html



Meghnad Saha
Meghnad Saha
Born	6 October 1893(1893-10-06) Shaoratoli, Dhaka (Present day Bangladesh)
Died	16 February 1956 (aged 62)
Residence	India
Nationality	Indian
Fields	Physics
Institutions	Allahabad University University of Calcutta
Alma mater	Dhaka College Presidency College, Kolkata
Known for	Thermal ionisation

Meghnad Saha FRS (Bangla:মেঘনাদ সাহা) (Devanagari: मेघनाद साहा) (October 6, 1893 – February 16, 1956) was an Indian astrophysicist best known for his development of the Saha equation, used to describe chemical and physical conditions in stars.

Life and work

Saha was born on October 6, 1893 in Shaoratoli village near Dhaka (in present Bangladesh). Son of Jagannath Saha, Megh Nad Saha belonged to a poor family and struggled to rise in life. He had his initial schooling at Dhaka Collegiate School, and later moved to Dhaka College. He was also a student at the Presidency College, Kolkata; 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 Fellow of the Royal Society in 1927. He was president of the 21st session of the Indian Science Congress in 1934.

Saha was fortunate to have brilliant teachers and class fellows. In his student days, Jagadish Chandra Bose and Prafulla Chandra Roy were at the pinnacle of their fame. Amongst his class fellows were Satyendra Nath Bose, Jnan Ghosh and J. N. Mukherjee. In later life he was close to Amiya Charan Banerjee, a renowned mathematician at Allahabad University.

Meghnad Saha's best-known work concerned the thermal ionisation of elements, and it led him to formulate what is known as the Saha equation. This equation is one of the basic tools for interpretation of the spectra of stars in astrophysics. By studying the spectra of various stars, one can find their temperature and from that, using Saha's equation, determine the ionisation state of the various elements making up the star.

Saha also helped build several scientific institutions, such as the Physics Department in Allahabad University and the Institute of Nuclear Physics in Calcutta. He founded the journal Science and Culture and was the editor until his death.¹ He was the leading spirit in organizing several scientific societies, such as the National Academy of Science (1930), the Indian Physical Society (1934), Indian Institute of Science (1935) and the Indian Association for the Cultivation of Science (1944). A lasting memorial to him is the Saha Institute of Nuclear Physics, founded in 1943 in Kolkata

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

He was also the chief architect of river planning in India. He prepared the original plan for the Damodar Valley Project.

Saha's own comment on his work was as follows:

“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.”²

Tributes to Saha

• "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 Narlikar³

• "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." - S. Rosseland⁴

• "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." - D. S. Kothari⁵

References

1. ^ Eminent scientists published by Scholastic India pvt. Ltd.
2. ^ "Meghnad Saha".
3. ^ Narlikar, Jayant (2003). The Scientific Edge. Penguin Books, 127. 
4. ^ Rosseland, S. (1939). Theoretical Astrophysics. Oxford: Oxford University Press. 
5. ^ Kothari, D. S. (1970). Biographical Memoirs of Fellows of the National Institute of Sciences of India 2. 

Further reading

• Obituary - The Observatory 76 (1956) 40

• Obituary - Proceedings of the Astronomical Society of the Pacific 68 (1956) 282

External links

• "Meghnad Saha".
• Biography
• Biography
• ScienceWorld: Saha Equation
• List of M. N. Saha's papers