Meghnad Saha

Derived the thermal ionization equation in a 1920 paper, which Britannica says became fundamental to all work on stellar atmospheres: it links a star's spectrum to its temperature and the abundance of its elements.

Used the theory to explain why rubidium and caesium lines are missing from the Sun's spectrum and to predict that they should appear in cooler sunspots, where H. N. Russell then found the rubidium lines.

Helped build Indian science institutions: first president of the Allahabad academy, driving force behind the Institute of Nuclear Physics in Calcutta (later named for him), and founder of the journal Science and Culture.

After writing a paper on the Harvard classification of stellar spectra, he withdrew it in London and spent about four months rewriting it with A. Fowler's criticism, publishing it in 1921 as 'On a physical theory of stellar spectra'.

This is consistent with openness to expert criticism when improving his own theory. Analytical Rigour

After independence he opposed setting up the Atomic Energy Commission at that time, arguing that India lacked the industrial base and trained people, and disagreed with Bhabha and Nehru on the approach.

This is consistent with willingness to hold a public position against more powerful figures. Conflict Tolerance

Awarded the Premchand Roychand Scholarship in 1919, he spent about two years in London and Berlin, where he worked in Fowler's and Nernst's laboratories and published his stellar-spectra theory in 1921.

This is consistent with a shift from isolated work in Calcutta to an international research network. Cross-Domain Range