Part 6/14:
Initially, electromagnetic and weak forces were separate, but a remarkable unification occurred, revealing they are two facets of the electroweak force. This union predicted four force carriers: W+, W−, Z0, and photons. However, the W and Z bosons are massive, unlike photons, indicating that the symmetry breaking process endows particles with mass.
How Symmetry Breaking Works
In the universe's early, extremely hot moments, forces appeared unified. As the universe cooled, a mechanism called spontaneous symmetry breaking occurred, driven by the Higgs field—a quantum field uniformly present everywhere.