Yet he made his career as an important director of India's railways, applying his mathematical skills there.
Upon retirement, he set out in writing several books, starting with Great Ideas of Modern Mathematics, popularizing science and targeting laymen.
Singh subsequently won the Kalinga Prize from UNESCO in 1963, being the first Indian and Asian to do so.
He was also chosen by Pakistan scientist and Nobel Prize winner in Physics in 1979, Abdus Salam to write his biography, which came out in 1992 published by Penguin books.
Jagjit Singh under the heading 'A MAN OF SCIENCE' Biographical note Frontispiece notes in 'Modern Cosmology' (retitled from 'Great ideas and Theories of Modern Cosmology'), Penguin (1961).