Why String Theory?
The most common question from lay-people about string theory is Why?. To understand why physicists study string theory rather than theories of surfaces or other objects we have to go back to its origins. In 1968 physicists were trying to understand the nature of the strong nuclear interactions which held the quarks together in nucleons. There was an idea about duality between scattering interactions which led Veneziano and Virasoro to suggest exact forms for the dual resonance amplitude. These amplitudes turned out to have interesting properties in 26 dimensions and various independent lines of research by Nambu, Nielson and Susskind led to the revelation that the amplitudes were derivable from a theory of strings. String theory was considered as a theory of strong interactions for some time. Physicists thought that the explanation for confinement of quarks was that they were somehow bound together by strings. Eventually this theory gave way to another theory called Quantum Chromo Dyna
