The Forgotten Landscape

Essay as originally posted on FQXi, August 31, 2012 (http://fqxi.org/community/forum/topic/1462). Abstract:

Contrary to common lore, the standard model of particle physics has a “landscape” of physically inequivalent vacua, most of them quite different from ours. I discuss some cosmological consequences and related observational constraints, show how non-perturbative electroweak dynamics selects our special vacuum, and put an old idea to rest.