multiverse
Beyond black holes – Area of study
Cosmogony – Branch of science or a theory concerning the origin of the universe
Eternity – Endless time or timelessness
Impossible world – Term used to model separate circumstances that cannot exist together
Measure problem (cosmology) – Concept in cosmology
Modal realism – Philosophical concept
Parallel universes in fiction – Universe coexisting with another universe
Philosophy of physics – Truths and principles of the study of matter, space, time and energy
Philosophy of space and time – Branch of philosophy relating to spatiality and temporality
Simulated reality – Concept of a false version of reality
Twin Earth thought experiment – Thought experiment proposed by Hilary Putnam
Ultimate fate of the universe – Theories about the end of the universe