grand unified theory 
noun Physics
A theory attempting to give a single explanation of the strong, weak, and electromagnetic interactions between subatomic particles.Scientists had believed that once the shortcomings of particle physics had been left behind by the adoption of the exotic string theory, that a grand unified theory of everything would be an easily ascertainable goal....
- Like physicists who are trying to make sense of the particles and forces that make up the physical world, knot theorists are looking for something akin to a grand unified theory that would explain all invariants and all knots.
- Science still seeks for a grand unified theory.