String Theory May Be The Closest To A "Theory Of Everything"

String theory suggests that the sub-atomic particles do not exist in points of space but are instead strings vibrating at different frequencies. The difference between different particles is that they may be vibrating on different frequencies. The theory proposes that one way these strings may be vibrating at different frequencies is due to sub-atomic particles called "Gravitons" where a Graviton mediates the gravitational force of interaction. String theory unifies Einstein's theory of gravity and particle physic, however, there is one problem, "String theory is purely theoretical..."