Bagchihas contributed broadly to physical chemistry. His theories have profoundlyinfluenced interpretation of contemporary experiments. Bagchi produced thefirst successful theory of barrierless chemical reactions and introducedmicroscopic and continuum theories of solvation dynamics and dielectricrelaxation. He coined the name “biological water” following his insightful works on the dynamics of hydrated proteins,DNA hydration layers, and protein-DNA interactions. Bagchi elaborated thetheory of Förster resonance energy transfer theory and detailed a mode coupling theoryof electrolyte conductance. He has authored three monographs on physicalchemistry. Importantly, his students are professors in the very bestinstitutions in India.