String Theory

String theory is a theoretical framework in physics that attempts to reconcile the two pillars of modern theoretical physics—quantum mechanics and general relativity. It posite that instead of point-like particles or fields, the fundamental building blocks of the universe are one-dimensional objects called strings.

In the set of notes on quantum field theory, we have seen how quantum field theory is the natural extension of quantum mechanics to fields. We have also discovered that applying the principle of locality to Newtonian gravity leads to a field theory of gravity, which is general relativity. However, there is a problem with this approach: quantum field theory is not compatible with general relativity.