Editing Multiverse (section)

==== Level II: Universes with different physical constants ====

In the [[eternal inflation]] theory, which is a variant of the [[Inflation (cosmology)|cosmic inflation]] theory, the multiverse or space as a whole is stretching and will continue doing so forever,<ref>{{cite serial |title=[[How the Universe Works#Season 3|How The Universe Works 3]]|episode=First Second of the Big Bang |network=[[Science (TV network)|Discovery Science]] |date=2014}}</ref> but some regions of space stop stretching and form distinct bubbles (like gas pockets in a loaf of rising bread). Such bubbles are embryonic level I multiverses.

Different bubbles may experience different [[spontaneous symmetry breaking]], which results in different properties, such as different [[physical constant]]s.<ref name="TegmarkPUstaple"/>

Level II also includes [[John Archibald Wheeler]]'s [[oscillatory universe]] theory and [[Lee Smolin]]'s [[Cosmological natural selection|fecund universes theory]].