The Grand Unification Epoch.

The GUT or TOE "Theory of Everything" is the unification of Relativistic and Quantum Physics, probably via String Theory.

The Grand Unification Theory used to be called the Unified Field Theory. It is a search for a theoretical/mathematical framework that can account for and unite all the basic forces, and therefore be considered a Theory of Everything. Currently there are 2 important branches of physics which seem to contradict each other. General Relativity which explains the behaviour of big systems and Quantum Mechanics which explains the behaviour of small systems (atomic/sub-atomic.) If you apply the wrong theory for the size of system then predictions from the theory don't match experimental results. (i.e. The theory is wrong!) Many physisists think there is a theory that can adequately explain both of these systems but they haven't found it yet. Einstein spent his last years attempting to find it. He did not. M theory, a development of string theory is currently considered by many to be the best prospect for a Grand Unification Theory.

Well, you still have your first principles, the things that are unproved and unprovable but which undergird all theories. When people speak of an all-encompassing theory they often are unawares that all theories must have unproven and unprovable parts to them.

Currently, to my knowledge, nobody has discovered a monopole (magnet with a single pole), although this is something that is predicted by super string theory and the grand unification theory.

So for now, in your everyday life, it is safe to say that a magnet always has two poles.