What is string theory ? (correct me if i am wrong) Why a new underlying theory was required when modern Physics was only one step away from establishing a G.U.T. (unification attempt for four fundamental forces out of which three could be clubbed.) using Tensor Flow ?
This article describes string theory.
In physics, string theory is a theoretical framework in which the point-like particles of particle physics are replaced by one-dimensional objects called strings. String theory describes how these strings propagate through space and interact with each other. On distance scales larger than the string scale, a string looks just like an ordinary particle, with its mass, charge, and other properties determined by the vibrational state of the string.
Why a new underlying theory was required when modern Physics was only one step away from establishing a G.U.T.
GUT , and normal field theoretical models have a problem with the mathematics, there are singularities when higher order terms are added that have to be taken out by hand. The effort for new theories is based on that, trying to find mathematically rigorous theories that would have no singularities.
Supersymmetry was proposed as one such possibility for the three forces, not including gravity.
String theory is explored by theorists because it has the possibility of including gravity in the model, and also embedding the standard model which is an encapsulation of practically all data up to now.