Unified Theories

One of the goals of physics is to draw seemingly unrelated theories together into a single, simple unified theory. The advantage of a unified theory over many fragmented theories is that a unified theory often offers a more elegant explanation of data and may point toward future areas of study.

For example, in 1861-65 James Maxwell explained the interrelation of electric and magnetic fields in his unified theory of electromagnetism. Then, in 1881-84 Hertz demonstrated that radio waves and light were both electromagnetic waves, as predicted by Maxwell's theory.

In the later years of his life Einstein tried, but failed, to write a theory which unified gravity with other theories.

Today, one of the major goals of particle physics is to unify strong, weak, and electromagnetic interactions into a "Grand Unified Theory" (or, G.U.T. if you prefer). Perhaps such a theory could tell us at what energies all forces merge into one.