ABSTRACT
The description of hadronic processes in the 1960s was based on models with an infinite number of states, lying on linear Regge trajectories. An important theoretical realization of these ideas was given by the Veneziano (1968) model, which actually describes the scattering of one-dimensional objects, strings. The inclusion of fermions into the theory laid the ground for supersymmetry (Ramond 1971, Neveu and Schwarz 1971). A radical change in the interpretation of the model has been suggested in the 1970s: the hadronic scale is replaced with the Planck scale; and the string model is interpreted as a framework for the unification of all basic interactions including gravity (Neveu and Scherk 1972, Scherk and Schwarz 1974). The importance of these ideas became completely clear in 1980s, after the discovery that string theory was free of quantum anomalies (Green and Schwarz 1984, 1985).
