Meghnad SahaFRS was an Indian astrophysicist who developed the Saha ionization equation, used to describe chemical and physical conditions in stars. His work allowed astronomers to accurately relate the spectral classes of stars to their actual temperatures. He was elected to the Parliament of India in 1952.
Saha's study of the thermal ionisation of elements 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. This work was soon extended by Ralph H. Fowler and Edward Arthur Milne. Saha had previously reached the following conclusion on the subject. Saha also invented an instrument to measure the weight and pressure of solar rays and helped to 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. He was the leading spirit in organizing several scientific societies, such as the National Academy of Science, the Indian Physical Society, Indian Institute of Science. He was the Director at Indian Association for the Cultivation of Science during 1953–1956. The Saha Institute of Nuclear Physics, founded in 1943 in Kolkata, is named after him. To actively participate in planning of education, industrialization, health, and river valley development Saha stood as a candidate in the constituency of North-West Calcutta in the 1951 Loksabha election. He ran on the ticket of Union of Socialists and Progressives but Saha always maintained his independence. He was pitted against a powerful and well-funded candidate from Congress, Mr. Prabhu Dayal Himatsingka. Saha was not well funded for his campaign and wrote to his publisher in November 1951 to ask for a Rs 5,000 advance against the sale of his textbook, Treatise on Heat, "because I am standing for election in the house of the people from NW Calcutta". Saha won the contest by a margin of 16%. Saha actively participated in the parliament in the areas of Education, Refugee and Rehabilitation, Atomic Energy, Multipurpose River Projects and Flood Control and long term planning. In the book "Meghnad Saha in Parliament" Saha is described as "Never unduly critical, Saha was so 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 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." 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 is as follows:
Tributes to Saha
"Meghnad Saha's ionization equation, which opened the door to stellar astrophysics was one of the top ten achievements of 20th century Indian science could be considered in the Nobel Prize class." — Jayant Narlikar
"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
"He 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
