2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/86326A relation connecting the {\it{rest mass}} and {\it{separation of events in space-time continuum}} is suggested and the idea of Compton scattering is used as a method for the determination of rest mass. An experiment involving collision of photons resulting in creation of rest mass is discussed theoretically in order to illustrate the connection formula.5 pages, 1 figure. Indian J. of Theo. Phys. Vol. 51, No.3 (2003) (will appear shortly)General Physicstext