Breaking Symmetry Built the Universe

Perfect symmetry is beautiful but sterile. In the first microseconds after the Big Bang, a near-perfectly symmetric field of energy cooled unevenly, and that tiny flaw tipped the balance: for every billion particles of antimatter, about a billion and one particles of matter survived. That sliver of surplus is everything we see today.

That one-sided outcome has a name, CP violation. Discovering it won the 1980 Nobel Prize in Physics; explaining how it arises won the 2008 prize. A related break in symmetry, the Higgs mechanism (2013 Nobel), is how particles gained mass in the first place.