alternative universe

• alternate universe (US)

alternative universe (plural alternative universes)

1. (physics, cosmology) A hypothetical world situated in a different dimension of space and time than the real world consisting of the universe known and experienced by human beings.
   • 2007 June 21, Bernard Carr, editor, Universe Or Multiverse?, page 367:

     In particular, it has been argued that if any of six (or perhaps a few more) numbers did not have rather particular values, then life as we know it would not be possible; atoms would not exist, or no grativationally bound structures would form in the Universe, or some other calamity would occur that would appear to make the alternative universe a very dull and lifeless place. How, then, did we get so lucky as to be here?

2. (literature, narratology) An imaginary realm, often a variant form of the real world, depicting a different way events could have unfolded or the universe could have functioned.
   • 2022 June 13, S. Sayyid, Recalling the Caliphate – Decolonization and World Order:

     This mirroring was marked out by the way in which the Federation of Planets, a voluntary association of different worlds, never existed in the alternative universe; instead we find ourselves confronting a vicious militaristic Terran empire.