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: 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. 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. 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, 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%. Saha participated in the areas of education, refugees, rehabilitation, atomic energy, multipurpose river projects, flood control, and long term planning. On the dust jacket flap of 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."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: ==Personal life==