  When first proposed in 1957, the BCS theory for superconductivity, which
explained the quasi-totality of its thermodynamic and transport properties, was
greeted with great circumspection, before it became the play ground of particle
physicists, who largely contributed to understand the deep physics behind this
phenomenon. In the course of this undertaking, revolutionizing new concepts in
physics were brought to light, such as (i) the "physical significance of the
phase" of a quantum mechanical wave function whose role in force-transmitting
gauge fields is to control the interaction between elementary particles in a
current conserving manner (ii) "spontaneous symmetry breaking" and its related
to it collective Nambu-Goldstone modes, which encode the basic symmetry
properties of a quantum vacuum and the associated to them conserved quatities,
(iii) The "Anderson-Higgs mechanism" and its associated to it, but so far
experimentally unconfirmed "Higgs field", which provides the introduction of
massive force transmitting gauge fields and ultimately the mass of elementary
particles. These concepts were vital in consolidating the standard model for
elementary particles and presented the final answer to what distinguishes a
superconducting from a non-superconducting state: "electromagnetic gauge
symmetry breaking", whatever the microscospic mechanism for that might be. We
illustrate here how these concepts gradually emerged, once the basic features,
which characterize superconductivity - the Meissner-Ochsenfeld magnetic field
screening and the fundamental London equations explaining them in a
phenomenological way - were established.
