Full Idea
In the very early hot universe the electromagnetic and weak nuclear forces were one. The early emergence of the Higgs field led to electroweak symmetry breaking. The W and Z bosons grew fat, and the photon raced away mass-free.
Gist of Idea
The symmetry of unified electromagnetic and weak forces was broken by the Higgs field
Source
New Scientist writers (Why the Universe Exists [2017], 07)
Book Reference
New Scientist writers: 'Why the Universe Exists' [John Murray 2017], p.129