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Gauge field theory

In physics, the widely accepted theories of the standard model are known as gauge field theories. What that means is, the fields in the standard model all exhibit a high degree of symmetry known as a gauge symmetry or a gauge transformation. All gauge fields are mediated by the massless 'gauge boson' group.

Even though in the Standard Model all forces exhibit this symmetry, it is not always obvious in the states one sees in nature. Sometimes, especially when temperature decreases, the symmetry gets spontaneously broken. A basic example of broken symmetry that is often given is a solid state magnet. It is composed of many atoms, each of which has a magnetic dipole moment. However, the laws of magnetism are rotationally symmetric, and so at high temperatures, the atoms will be randomly aligned, and the rotational symmetry will be restored. Similarly, you can, under the right conditions, super-cool water to below freezing point. When an ice crystal is dropped into the liquid, the symmetry is broken and it solidifies instantly.