““SYMMETRY BREAKING The preferential direction fixed by this spontaneous symmetry breaking will now determine which among the elementary particles will share in the strong interaction and which will not. The gist is that the spontaneous symmetry breaking sees to it that, in addition to gravity, the one unified force that knew no preferential direction in the abstrat space of particle properties is now split into two distinguishable forces-the strong force and the electroweak force. The symmetry that broke down in this phase transition is what we call GUT symmetry. Formally speaking, GUT symmetry breaking, which permits us to tell the difference between the strong force and the electroweak force, is equivalent to symmetry breaking in the ferromagnet. As one direction in space is spontaneously chosen as a preferential one, a field emerges and, simply by differing from zero, points in some given direction, breaking the previous symmetry. In the ferromagnet, this field is the magnetization; in our cooling universe, it is the Higgs field.””
