the physicist Jeffrey Goldstone discovered that a hallmark of such symmetry breaking would be the existence of other massless particles, now called Nambu-Goldstone (NG) bosons, whose interactions with other matter would also reflect the nature of the sym- metry breaking. An analogy of sorts can be made here to

perconductor comes about as the condensate oscillates in response to the passing electro- magnetic wave. In particle physics language, the massless Nambu-Goldstone modes that correspond to the particle version of the otherwise vanishingly small energy oscillations in the condensate get "eaten" by the electro-