Explain spontaneous symmetry breaking in physics.
Spontaneous symmetry breaking is a mechanism, not a miracle. It describes a situation where the underlying laws of physics possess a certain symmetry, but the lowest energy state of the system, the vacuum, does not exhibit this symmetry. Think of a ferromagnet below its Curie temperature; the microscopic interactions are rotationally invariant, but the bulk material develops a preferred magnetic orientation. This orientation is dictated by an 'order parameter.' In particle physics, this 'order parameter' is related to the vacuum expectation value of a field, which spontaneously breaks a gauge symmetry, leading to massive gauge bosons.
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