GRAND UNIFICATION

As the universe cooled it entered the realm of workable physics.

The epoch of Grand Unification refers to that fleeting instant between 10^-43 and 10^-33 second when electromagnetism, weak force and strong force were indistinguishable.

This initial symmetry was broken as the universe cooled down further. The separation of strong force from the remaining "electroweak" force marked the end of Grand Unification.