Why this matters now
Saha is tested for the Saha ionization equation, his role in reforming the Indian National Calendar (Saka), his work on the Damodar Valley Corporation (DVC) and his social activism (he was elected an MP from North-West Calcutta in 1952 on an independent ticket).
The Saha Ionization Equation (1920)
While at the University College London in 1920 working under Alfred Fowler, Saha derived an equation relating the ionization state of an element in a stellar atmosphere to its temperature, pressure and ionization energy. The equation explained for the first time why stellar spectra show different absorption lines at different surface temperatures (O/B/A/F/G/K/M classification). It is the foundation stone of theoretical stellar astrophysics and is still used today.
Institutions: IACS, Allahabad, Calcutta, INSA
Saha was a founder of the Indian Physical Society (1934) and led the Indian Science Congress in 1934. He was Professor at Allahabad (1923-38) and then Khaira Professor of Physics at Calcutta University (1938-56). He founded the Saha Institute of Nuclear Physics, Calcutta (1950) — India’s premier institute for nuclear physics research, still functioning under DAE.
Public service: DVC, Calendar Reform, MP
Saha was a member of the National Planning Committee under Nehru (1940), and was instrumental in conceiving the Damodar Valley Corporation (DVC) (1948) modelled on the Tennessee Valley Authority. He chaired the Calendar Reform Committee (1952) which adopted the Saka Era as India’s National Calendar from 22 March 1957. He was elected an Independent MP from North-West Calcutta (1952). He died of a heart attack at the Planning Commission office, New Delhi, on 16 February 1956 aged 62.
UPSC angle
Know Meghnad Saha — Saha ionization equation (1920, University College London under Alfred Fowler), foundation of stellar spectroscopy; founded Indian Physical Society (1934), Saha Institute of Nuclear Physics SINP Calcutta (1950) under DAE; member National Planning Committee under Nehru (1940); conceptualised Damodar Valley Corporation DVC (1948, after TVA model); CHAIRED Calendar Reform Committee 1952 → Saka Era adopted as India’s National Calendar from 22 March 1957; independent MP from North-West Calcutta (1952); died 16 Feb 1956.
Frequently asked questions
What is the Saha Ionization Equation?
An equation derived by Meghnad Saha in 1920 relating the ionization state of an element in a stellar atmosphere to its temperature, pressure and ionization energy — foundational to stellar spectroscopy.
What is the Saha Institute of Nuclear Physics?
India’s premier nuclear physics research institute, founded by Saha in 1950 at Calcutta. Still functioning under DAE.
What was the Calendar Reform Committee?
A 1952 Government of India committee chaired by Saha that recommended adopting the Saka Era as India’s National Calendar, effective from 22 March 1957.
Did Saha hold any political office?
Yes — he was elected Independent MP from North-West Calcutta in the 1952 general election.